JPH0645194A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To provide an electrolytic capacitor which can be easily sealed up, more lessened in size, less deteriorated in capacitance, enhanced in long term reliability, and easily laminated. CONSTITUTION:Crosslinked polyether polyol, ammonium borodisalicylate, polyethylene glycol dimethyl ether, and methyl etchyl keton are mixed together by stirring into ionic conduction adhesive agent, solution, the adhesive agent solution concerned is applied onto the surfaces of eight sheets of aluminum foil anodes 1 where an aluminum oxide dielectric layer 3 are formed respectively and nine sheets of aluminum foil cathodes 4 and cured, the cathode 4, the ionic conduction adhesive agent layer 6, the anode 1, the ionic conduction adhesive agent layer 6, and the cathode 4 are repeatedly laminated in this sequence for the formation of a laminate whose both outermost layers are the cathodes 1. An anode lead 2 and a cathode lead 5 are spot-welded, and all the laminate provided with the leads 5 and 2 is sealed up with a polypropylene sheet 7.

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 type electrolytic capacitor using an ion conductive adhesive.

[0002]

2. Description of the Related Art Conventionally, as a constituent material of an electrolytic capacitor, a dielectric made of an oxide such as aluminum oxide is used as a dielectric layer, and an organic electrolytic solution prepared by dissolving an ammonium salt in a high boiling organic solvent such as ethylene glycol is used as an electrolytic solution. The element structure of the electrolytic capacitor using these is such that an aluminum anode foil on which a dielectric oxide film is formed as the dielectric layer and an aluminum cathode foil with a separator paper interposed therebetween are wound. By the way, the mainstream was a wound type in which the separator paper was impregnated with the electrolytic solution. Also, as for the electrolytic capacitor for strobes incorporated in a camera or the like, one having almost the same configuration is used.

[0003]

However, a capacitor simply sealed by using such an electrolytic solution cannot obtain long-term reliability due to leakage of liquid or evaporation of the electrolytic solution, and thus epoxy resin or the like cannot be obtained. It has been difficult to perform sealing with the resin described above, or simple sealing with a heat-meltable polyolefin film such as polypropylene film or polyethylene film, or a sheet.

Further, the wound-type electrolytic capacitor has a problem that the wound coil component affects the high frequency range characteristics, and there is an unnecessary space such as the winding core and the lead-out portion due to the structure, and as a result, The volume occupied by capacitors in electrical equipment was so large that it could not be ignored.
Further, as a strobe capacitor incorporated in a camera, a wound electrolytic capacitor is so large that the volume inside the camera cannot be ignored. Further, when a laminated type element is prepared using an electrolytic solution, it is difficult to superimpose 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 decrease due to repeated charging and discharging, and can be made smaller. An object is to provide an electrolytic capacitor having long-term reliability.

[0006]

In order to solve the above problems, the electrolytic capacitor of the present invention has the following constitution. (1) At least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, wherein the anode and the cathode are the ion conductive. An electrolytic capacitor that is bonded with an adhesive.

(2) At least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, wherein the anode and the cathode are the ions. 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.

(3) At least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, and the anode and the cathode are An electrolytic capacitor having a laminated structure in which an ion conductive adhesive is repeatedly adhered alternately, and the outermost layer constituting the laminated structure is the electrically conductive cathode.

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

[0010]

The electrolytic capacitor of the present invention according to the above item (1) comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide. In addition, since the anode and the cathode are adhered with the ion conductive adhesive, a laminated electrolytic capacitor can be simply constructed. Also,
Since the electrolytic solution consists of an ion conductive adhesive, there is little evaporation of the electrolytic solution and therefore simple sealing is possible, excellent frequency characteristics, less capacity loss due to long-term storage and less capacity loss due to repeated charge and discharge, and long-term reliability. It is possible to provide an electrolytic capacitor having excellent properties, further, it is possible to eliminate a large unnecessary space such as a winding core, and it is possible to further reduce the size and reduce the volume occupied in the electric device.

Further, as described in the above item (2), it comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon. The anode and the cathode are adhered with the ion conductive adhesive, and the cathode, the ion conductive adhesive, the anode, the ion conductive adhesive, the constitution of an electrolytic capacitor laminated in the order of cathode and By doing so, in addition to the above-mentioned function, each element constituting the electrolytic capacitor can be efficiently used, and the capacitance of the capacitor can be further increased.

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

Further, as described in the above item (4), by using the electrolytic capacitor described in the above item (3) as a laminated electrolytic capacitor for strobe, a laminated electrolytic capacitor for strobe can be simply constructed. 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 polyether skeleton as a basic skeleton and the polyether moiety is a cross-linking polymer compound which is a random copolymer of oxyethylene and oxypropylene. By adopting a preferred embodiment of the present invention, which is an ion-conductive pressure-sensitive adhesive comprising a body and an ammonium salt and an ammonium salt-soluble plasticizer, an electrolytic capacitor having a high ion conductivity can be obtained, and the above-mentioned action is further exerted. It is possible and preferable.

[0015]

EXAMPLES The basis of the present invention comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon. An electrolytic capacitor is configured by bonding the cathode with the ion conductive adhesive.

As the ion conductive adhesive, for example, a crosslinked body of a polymer compound represented by the following formula (Formula 1), which has a polyether skeleton as a basic skeleton and a polyether moiety is a random copolymer of oxyethylene and oxypropylene And an ammonium salt and a plasticizer.

[0017]

[Chemical 1]

However, in the compound of the above (Chemical formula 1), 2
It is preferable that ≦ (n + m) × l ≦ 100. Examples of the cross-linked product of the polymer compound (Chemical formula 1) include those obtained by urethane-crosslinking the end groups of the polymer compound (Chemical formula 1) with diisocyanate, and acrylated the end groups of the polymer compound (Chemical formula 1) Those which are crosslinked by irradiation with rays or ultraviolet rays, or those in which the terminal group of the polymer compound (Chemical formula 1) is isocyanated and crosslinked with a compound having a plurality of active hydrogens such as water, polyols, polyamines, etc. Can be mentioned. The molecular weight of these polymer compounds (the molecular weight before crosslinking) is not particularly limited, but is 1,000 to 1
It is preferably about 10,000.

Any ammonium salt may be used as long as it is soluble in the above-mentioned polymer compounds and plasticizers and can be dissociated, and 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 Examples thereof include tetraethylammonium sulfonate. These may be used alone or in combination of two or more. Among these, ammonium borodisalicylate, ammonium benzoate, ammonium adipate, ammonium azelate and the like are particularly preferable in terms of high ionic conductivity in the crosslinked polymer compound. Although these ammonium salts are not particularly limited, they are used in the range of about 1 to 30% by weight based on the above-mentioned ion conductive adhesive.

As the plasticizer, a high boiling point 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 and tetraethylene glycol, and Examples thereof include polyalkylene glycol dialkyl ethers such as triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether.
You may use it in mixture of 2 or more types. The plasticizer is preferably used from the viewpoints of improving ionic conductivity, improving properties at low temperatures, and improving tackiness of a crosslinked polymer. The amount of the plasticizer used varies depending on the type and molecular weight of the polymer compound used, the degree of cross-linking, the type of the plasticizer, etc., so it is difficult to specify unconditionally, but usually 30 to 80% by weight relative to the ion conductive adhesive
Used to a degree.

The thickness of such an ion-conductive pressure-sensitive adhesive layer varies depending on the size of the electrolytic capacitor, the type and composition of the ion-conductive pressure-sensitive adhesive, etc., but it is difficult to specify unconditionally, but usually one anode and one cathode. 5 in the thickness laminated between
It is about 100 μm.

As the electrically conductive electrode, aluminum,
Tantalum and titanium can be used. Of these,
Aluminum and tantalum are preferable. It is to be noted that these electrodes are usually preferably used in order to increase the effective surface area of the electrodes, so that the surfaces thereof are etched to form fine etching holes.

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

As described above, the electrolytic capacitor of the present invention can be made 10% to 30% smaller than the conventional wound type capacitor, a thin capacitor can be obtained, and the space in the electric equipment can be effectively used. It will be possible. Therefore, when it is used as a laminated electrolytic capacitor for a strobe incorporated in a camera, for example, a disposable camera, it does not take a large space in the camera container and is useful.

Specific examples and comparative examples of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of the configuration of an electrolytic capacitor according to an embodiment of the present invention. Thickness 0.
Anode 1 made of aluminum foil with a diameter of etching holes of about 1 to 5 microns and a size of 3 cm x 12 cm 1
Boric acid solution (concentration 80 g /
1), the aluminum surface was oxidized at a current of 3 A for 15 minutes to form a dielectric layer 3 composed 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 aluminum foil of m was used as the cathode electrode. Next, in the structural formula (Formula 2), (n + m) × l =
A stock solution of the ion conductive adhesive was prepared by stirring and mixing 4.4 g of the polymer compound represented by 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]

[Chemical 2]

However, in the above (formula 2), (n + m)
X1 = 50. Subsequently, this was applied onto both surfaces of the anode 1 on the surface of the dielectric layer 3 and cured by standing in air at 30 ° C. for 3 hours. A total of 8 sheets were created by the same operation. Next, the ion conductive adhesive stock solution is applied to 9 aluminum foils of the cathode 4 to evaporate the contained methyl ethyl ketone, and then the cathode foil, the anode foil, the cathode foil,
Anode foil and cathode foil are repeatedly face-to-face pressure-bonded repeatedly at 30 ° C.
The electrolyte stock solution is cured by storing in air for 3 hours to obtain a laminate in which the cathode foil, the ion conductive adhesive layer 6, the anode foil, the ion conductive adhesive layer 6, and the cathode foil are repeatedly formed in this order. It was The anode foil and the cathode foil are 5 mm from each other.
It was made by shifting and taking the lead-out portion into consideration. The anode lead 2 and the cathode lead 5 were drawn out by spot welding.

Finally, by sealing the whole with a polypropylene sheet 7, the length of this embodiment is 12.5 cm and the width is 3 c.
An electrolytic capacitor A having a thickness of m and a thickness of 0.23 cm was prepared.
The ion-conductive polymer composition stock solution was applied using a nozzle having a liquid aperture of 0.5 mm, a nitrogen pressure of 3 kg / cm ² and a volume of 1 l / hr. It was carried out by spraying the above-mentioned stock solution of the ion conductive pressure-sensitive adhesive from the vertical direction of the electrode (from the top of the dielectric layer in the case of an anode) with a spray amount of. The coating method is as follows. The nozzle is fixed at a height of 10 cm in the vertical direction of the electrode, and the dielectric electrode is run laterally at a constant speed of 1.6 cm / sec.
This was performed by applying a nozzle spray angle of 22 degrees. The thus-prepared stock solution of the ion conductive polymer composition had a thickness of 0.06 mm and a difference within 20%.

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

The thickness is 0.1 mm and the diameter of the etching hole is about 1
~ 5μm, 2.8cm × 96cm size aluminum foil was kept at a temperature of 90 ℃ boric acid aqueous solution (concentration 80g
/ L) and a dielectric layer made of aluminum oxide was formed by oxidizing the aluminum surface at a current of 3 A for 120 minutes, and finally, the anode lead was spot-welded to form 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 form 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, a separator made of kraft paper having a density of 0.60 g / cm ² was wound up, and an electrolytic solution containing ethylene glycol and ammonium adipate as a main component was used for 1T.
After vacuum impregnation with orr, it was stored in an aluminum tube and the lead portion was sealed with an epoxy resin to obtain an electrolytic capacitor B of a comparative example having a target radius of 0.9 cm and a height of 4 cm.

With respect to the electrolytic capacitor A of the example and the electrolytic capacitor B of the comparative example produced as described above,
The frequency characteristics of impedance and capacity, life characteristics at 75 ° C., and charge / discharge cycle were evaluated. The results are shown in FIGS. 2 to 5 and Table 1. 2 to 5, the curve marked with a circle represents the characteristic of the electrolytic capacitor A of this embodiment, and the curve marked with a triangle represents the characteristic of the electrolytic capacitor B of the comparative example. .

In FIG. 2, the vertical axis and the horizontal axis are respectively
Impedance and measurement frequency. By this evaluation, the electrolytic capacitor A of the example is the electrolytic capacitor B of the comparative example.
It was found to give impedance equal to or higher than.

In FIG. 3, the vertical axis and the horizontal axis are respectively
Capacity and measurement frequency. From this evaluation, it was found that the electrolytic capacitor A of the example provided a capacity equal to or higher than that of 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 has a sufficiently high withstand voltage as compared with the electrolytic capacitor B of the comparative example.

[0038]

[Table 1]

The vertical axis of FIG. 4 represents the relative value of the capacity to the initial capacity of the electrolytic capacitor, and the horizontal axis represents the storage time at 75 ° C. As shown in FIG. 4, the electrolytic capacitor B of the comparative example is
If it is stored at 75 ° C, the capacity will be reduced early. On the other hand, 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 represents the relative value of the discharge capacity to the initial discharge capacity of the electrolytic capacitor, and the horizontal axis represents the number of charge / discharge cycles. The discharge capacity is 10V at 330V with an electrolytic capacitor.
It was evaluated by measuring the amount of electricity flowing when short-circuited for 5 minutes after charging for 5 minutes. As shown in FIG. 5, the electrolytic capacitor B of the comparative example has a reduced capacity at an early stage. On the other hand, it can be seen that the electrolytic capacitor A of the example maintains 70% of the initial capacity even after 10,000 cycles.

Comparing the capacities of the capacitors, the electrolytic capacitor B of the comparative example has a size of 10 cm ³ , whereas the electrolytic capacitor A of the embodiment has a size of 8 cm ³ , and the size is reduced by 20% while having the same capacity. I was able to. Therefore, the limited volume space can be effectively used as a laminated electrolytic capacitor for various electric devices and strobes of 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 electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide, and the anode and the cathode are the ions. Electrolytic capacitors that are bonded with a conductive adhesive have superior frequency characteristics compared to conventional electrolytic electrolytic capacitors, and because they do not evaporate and dissipate the electrolyte, they can be easily sealed, resulting in reduced capacity due to long-term storage and repeated charging. It is possible to produce an electrolytic capacitor having a long life and a decrease in capacity due to discharge. Further, the volume of the capacitor itself can be reduced, a thin capacitor can be obtained, and an electrolytic capacitor capable of effectively utilizing the space in the electric device can be provided.

Further, it comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, wherein the anode and the cathode are the ion conductive materials. In addition to the above effects, an electrolytic capacitor which is adhered with a conductive adhesive and in which a cathode, an ion conductive adhesive, an anode, an ion conductive adhesive and a cathode are laminated in this order Each of the elements constituting the above can be efficiently used, and an electrolytic capacitor having a larger capacitance can be provided.

Further, it comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide, and the anode and the cathode are ion In addition to the above effects, the electrolytic capacitor has a laminated structure in which the conductive adhesive is repeatedly and alternately adhered, and the outermost layer constituting the laminated structure is the electrically conductive cathode. Each of the elements constituting the above will be used more efficiently, and an electrolytic capacitor having a larger capacitance can be provided.

By using the above electrolytic capacitor as a laminated electrolytic capacitor for strobes, a laminated electrolytic capacitor for strobes can be simply constructed, and the volume occupied by the capacitor in the camera can be reduced. Is possible and preferable.

Further, the ion conductive pressure-sensitive adhesive has a crosslinked body of a high molecular compound having a polyether skeleton as a basic skeleton and a polyether portion being a random copolymer of oxyethylene and oxypropylene, an ammonium salt and an ammonium salt-soluble plastic. By using an ion-conductive pressure-sensitive adhesive composed of an agent, an electrolytic capacitor having high ion conductivity can be provided, and an electrolytic capacitor that can further exert the above-mentioned effects can be provided.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram of electrolytic capacitors of an example of the present invention and a comparative example.

FIG. 3 is a characteristic diagram of electrolytic capacitors of an example of the present invention and a comparative example.

FIG. 4 is a characteristic diagram of electrolytic capacitors of an example of the present invention and a comparative example.

FIG. 5 is a characteristic diagram of electrolytic capacitors of an example of the present invention and a comparative example.

[Explanation of symbols]

 1 Anode 2 Anode Lead 3 Dielectric Layer 4 Cathode 5 Cathode Lead 6 Ion Conductive Adhesive Layer 7 Polypropylene Sheet

Claims (5)

[Claims] 1. An ion conductive pressure-sensitive adhesive, an electroconductive cathode, and an electroconductive anode having a dielectric made of a metal oxide formed thereon, and the anode and the cathode are the ions. An electrolytic capacitor that is bonded with a conductive adhesive. 2. An ion conductive pressure-sensitive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, wherein the anode and the cathode are the ion conductive materials. Adhered with a transparent 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 ion conductive pressure-sensitive adhesive, an electrically conductive cathode, and an electrically conductive anode having a dielectric made of a metal oxide formed thereon, and the anode and the cathode are ions. An electrolytic capacitor having a laminated structure in which a conductive adhesive is alternately and repeatedly adhered, and 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 laminated electrolytic capacitor for strobes. 5. An ion conductive pressure-sensitive adhesive having a polyether skeleton as a basic skeleton, and a polyether portion being a cross-linked polymer of 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