JP2012104789A - Sealing body for electrolytic capacitor and electrolytic capacitor using sealing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic capacitor which prevents an electrolytic solution from leaking from a sealing body in a high temperature atmosphere due to deterioration of the sealing body, and to provide the sealing body.SOLUTION: A sealing body 6 has an insertion hole 9 for an electrode terminal formed by tightly joining a first sealing body element 7 which is made of silicone rubber and is formed in a columnar shape and a second sealing body element 8 which is made of a thermoplastic resin and is formed in a disc shape through a thin film layer 12 of an adhesive formed of a chemical treatment agent by at least pressurizing the elements. The electrolytic capacitor has the first sealing body element 7 arranged on the inner side of a cylindrical case 5, has an electrode terminal 2 airtightly provided in the insertion hole 9 for the electrode terminal of the sealing body 6, and has the sealing body 6 airtightly provided in an opening part 51 of the case 5, so that an end edge 52 of the opening part of the case 5 is caulked, and thereby the opening part 51 of the case 5 is sealed.

Description

  The present invention relates to a sealing body for an electrolytic capacitor and an electrolytic capacitor using the sealing body.

  Electrolytic capacitors use a sealing body that seals the electrolyte so that it does not leak to the outside. As represented mainly by aluminum electrolytic capacitors, they can be easily obtained in a small size and a large capacity. Although employed in equipment, if the electrolyte leaks out from the sealing body or evaporates, there is a problem that the service life of the electrolytic capacitor is shortened. In particular, electrolytic capacitors used for power control of automobiles and the like are used in a high temperature atmosphere of about 150 ° C., and a sealing body made of a rubber material is likely to be thermally deteriorated, and the electrolytic solution is transferred from the sealing body to the outside. There is a problem that leakage or evaporation tends to occur and the service life of the electrolytic capacitor is shortened.

  As a factor that causes the electrolyte solution to leak out from the sealing body using the rubber material or to evaporate, first, the first factor is that the electrolyte solution penetrates into the sealing body due to the permeability of the rubber material. Therefore, in order to solve this problem, for example, as in Patent Document 1, a silicon swelling layer is formed on the entire surface of the sealing body made of butyl rubber, and the penetration of the electrolytic solution into the sealing body by utilizing its water repellency. A sealing body using a rubber material that suppresses the electrolyte and suppresses the decrease in the electrolyte has been proposed. Patent Document 2 proposes a sealing body having a structure in which a resin plate is attached to the upper surface of a rubber stopper (corresponding to a sealing body using a rubber material) and a liquid epoxy resin is impregnated into the resin plate.

  In addition, as a second factor, the use environment of electrical equipment and electronic equipment itself in which electrolytic capacitors are employed has become high temperature, and rubber materials such as butyl rubber, ethylene propylene rubber and natural rubber have been conventionally used despite the low heat-resistant limit temperature. Is used for the sealing body, and this rubber material is deteriorated under high temperature use. Therefore, in order to solve the problem that the function of sealing the electrolyte solution deteriorates in combination with the thermal deterioration of the rubber material, a conventional resin plate is attached to the rubber lid of the case as in Patent Document 3. The sealing body using a rubber material such as butyl rubber, ethylene propylene rubber or natural rubber is improved, and a heat-resistant and chemical-resistant film (for example, polyethylene resin or silicon rubber) is used on the outer surface of the rubber material instead of the resin plate. ) To prevent deterioration of these rubber materials by heat and chemicals.

  However, in the proposal according to Patent Document 1, the electrolyte is prevented from evaporating due to the electrolyte penetrating into the sealing body even under high temperature use, but the rubber material used for the sealing body is used under high temperature use. The second factor has not been eliminated because no consideration has been given to deterioration.

  Further, in the proposal according to Patent Document 2, consideration is given to preventing the electrolytic solution from permeating from the rubber plug, but the resin plate and the rubber plug are brought into close contact with each other even though a work process for impregnating the liquid epoxy resin is required. There is no consideration to prevent the electrolyte that has been joined and permeated from the rubber plug from leaking between the resin plate and the rubber plug, so the factors that cause the electrolyte to leak or evaporate can be eliminated. Absent.

  Further, in the proposal according to Patent Document 3, a rubber material having a heat resistant temperature lower than about 150 ° C. such as butyl rubber, ethylene propylene rubber or natural rubber is selected as the rubber material used for the sealing body. It is easily damaged by high temperature atmosphere. Moreover, in the heat-resistant and chemical-resistant film formed on the outer surface of the sealing body using a rubber material, when used as a sealing body for an electrolytic capacitor that seals the opening of the case by crimping the edge of the opening of the case, The coating formed on the outer surface of the sealing body at the tip of the opening edge of the case is easily damaged, and the inner peripheral surface of the opening edge of the case is pressed against the outer peripheral surface of the rubber material in the radial direction. The coating formed on the outer surface of the body is easily damaged by mechanical stress. When such coating damage occurs, the electrolyte that has penetrated into the sealing body from the rubber material leaks to the outside or evaporates. However, the factor that the electrolyte leaks to the outside or evaporates cannot be solved.

JP-A-8-138981 JP-A-8-153654 Japanese Utility Model Publication No. 61-190125

  In order to solve the above problems, the present invention selects silicon rubber when using a rubber material as a sealing body of an electrolytic capacitor used in a high temperature atmosphere of about 150 ° C., and this silicon rubber is used as an electrolyte. Although it is a rubber material that has chemical resistance and heat resistance, it has not been used in the past, so we studied how it can be used as a sealing body for electrolytic capacitors, It aims at providing the electrolytic capacitor which prevents electrolyte solution from leaking from a sealing body under.

  The electrolytic capacitor sealing body of the present invention (hereinafter sometimes referred to as a sealing body) is an electrolytic capacitor sealing body having electrode terminal insertion holes, and has a first insertion hole and made of silicon rubber. Either one of the surfaces for joining the first sealing element formed in a cylindrical shape and the second sealing element formed in a disk shape having a second insertion hole and made of a thermoplastic resin. Chemical treatment with any of mercapto group, thiocarbonyl group, cyano group, isocyanate group, amino group, ammonium group, pyridinium group, azinyl group, carboxyl group, benzotriazole group, triazine thiol group, etc. An adhesive thin film layer made of an agent is formed, the first insertion hole and the second insertion hole are communicated with each other, and the first sealing body element and the second sealing body element are polymerized through the thin film layer. In the state The electrolytic capacitor of the present invention is characterized in that the electrode terminal insertion hole is formed by at least pressurizing and closely bonding the first sealing element and the second sealing element. An electrolytic capacitor formed by closing an opening of a cylindrical case containing the electrolytic capacitor with the sealing member for electrolytic capacitor, wherein the first sealing element is a second sealing member inside the case. The sealing body is arranged so that the body element becomes the outer surface, and the electrode terminal is provided in an airtight manner in the electrode terminal insertion hole of the sealing body, and the opening edge of the case is caulked, and the tip of the opening edge Presses the outer surface of the second sealing body element in the height direction, and the inner peripheral surface of the edge of the opening presses the outer peripheral surface of the first sealing body element in the radial direction to thereby contact the opening of the case. Provide a sealing body in an airtight manner Characterized by comprising a mouth portion is sealed.

  The sealing body for an electrolytic capacitor of the present invention is a sealing body for an electrolytic capacitor having an insertion hole for an electrode terminal, and is a first sealing body having a first insertion hole and formed in a cylindrical shape made of silicon rubber. A mercapto group, a thiocarbonyl group, or a cyano group is formed on any one of the surfaces that join the element and the second sealing element having a second insertion hole and formed in a disc shape made of a thermoplastic resin. Forming a thin film layer of an adhesive composed of a chemical treatment agent such as isocyanate group, amino group, ammonium group, pyridinium group, azinyl group, carboxyl group, benzotriazole group, triazine thiol group, or a combination thereof. The first sealing body element and the first sealing body element in a state where the first sealing body element and the second sealing body element are polymerized through the thin film layer by communicating the first insertion hole and the second insertion hole. Second sealing body Since the electrode terminal insertion hole is formed by pressurizing the element at least by pressurizing the element, the hole processing after molding is generally performed for a molded product made of silicon rubber such as the first sealing element. Although it is difficult, since the first insertion hole constituting the electrode terminal insertion hole may be formed in advance in the mold at the time of molding, it is not necessary to drill the first sealing body element formed into a cylindrical shape. Thus, a sealing body which is not affected by the electrolyte solution by the silicon rubber of the first sealing body element and hardly deteriorates is obtained. The electrolytic capacitor of the present invention is an electrolytic capacitor in which an opening of a cylindrical case containing a capacitor element and an electrolytic solution is closed with the electrolytic capacitor sealing body. The sealing element is disposed so that the sealing element is on the inner side of the case and the second sealing element is on the outer surface, and the electrode terminal is hermetically provided in the electrode terminal insertion hole of the sealing element. The opening edge is crimped, the tip of the opening edge presses the outer surface of the second sealing element in the height direction, and the inner peripheral surface of the opening edge is the outer peripheral surface of the first sealing element. The sealing body is hermetically provided in the opening of the case by pressing in the radial direction, and the opening of the case is sealed, so even if the electrolytic capacitor is used in a high temperature atmosphere of about 150 ° C., The sealing body is not easily deteriorated thermally, and the electrolyte solution The electrolyte solution leaks from a portion where the first sealing body element and the second sealing body element are joined while preventing the electrolytic solution from penetrating from the first sealing body element and leaking from the second sealing body element. Since it is prevented from coming out, the cause of the electrolyte leaking out from the sealing body or evaporating can be eliminated, and the service life of the electrolytic capacitor can be extended.

It is sectional drawing which shows the sealing body for electrolytic capacitors which shows embodiment of this invention. It is sectional drawing of the electrolytic capacitor using the sealing body for electrolytic capacitors same as the above.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 illustrates an embodiment of a sealing body used in an opening of a cylindrical case of an electrolytic capacitor.

  The first sealing element 7 is a molded product made of silicon rubber and formed into a cylindrical shape having a pair (left and right in FIG. 1) of first insertion holes 10. The diameter and height of the first sealing element 7 are those of an electrolytic capacitor described later. What is necessary is just to set with the magnitude | size which seals the opening part 51 of the cylindrical case 5. FIG.

  On the other hand, the second sealing element 8 is a molded product made of a thermoplastic resin material and formed into a disk shape having a pair of second insertion holes 11, and the diameter thereof is the diameter of the first sealing element 7. The thickness is smaller than the height of the first sealing element 7. As the thermoplastic resin material of the second sealing body element 8, PBT resin (polybutylene terephthalate resin) or PPS resin (polyphenylene sulfide resin) is desirable.

  Further, either the upper surface of the first sealing body element 7 or the lower surface of the second sealing body element 8, that is, the surface where the first sealing body element 7 and the second sealing body element 8 face each other. On one side, a chemistry such as a mercapto group, thiocarbonyl group, cyano group, isocyanate group, amino group, ammonium group, pyridinium group, azinyl group, carboxyl group, benzotriazole group, triazine thiol group, or a combination thereof A thin film layer 12 of an adhesive made of a general treatment agent is formed. In this case, the thin film layer 12 may also be formed on the inner peripheral surface of the first insertion hole 10 or the second insertion hole 11 of the pair of electrode terminal insertion holes 9.

  Further, the upper surface of the first sealing body element 7 and the lower surface of the second sealing body element 8 are polymerized and pressurized so as to make the first insertion hole 10 and the second insertion hole 11 communicate with each other. Preferably, the thin film layer 12 generates a chemical adhesive action by heating and pressurizing at a temperature of 50 ° C. to 100 ° C., thereby closely bonding the first sealing element 7 and the second sealing element 8. Thus, a cylindrical sealing body 6 in which a pair of electrode terminal insertion holes 9 is formed is obtained.

  Next, FIG. 2 shows a schematic view of an electrolytic capacitor using the sealing body 6, and a cylindrical case 5 made of a metal material such as an aluminum material having an opening 51 at the upper end and capable of caulking processing is provided with an anode. A capacitor element 1 in which a pair of electrode plates 41 and 42 of a cathode is impregnated with an electrolytic solution 3 such as ammonium phosphate, ammonium borate, or ammonium adipate is accommodated. The capacitor element 1 is provided with an electrode terminal 2 including a pair of lead terminals 21 and 22 electrically connected to a pair of electrode plates 41 and 42. The electrode terminal 2 is provided on the sealing body 6 so as to protrude outward from the case 5 through the pair of electrode terminal insertion holes 9 of the sealing body 6 or to be exposed by bending.

  As shown in FIG. 2, the first sealing body element 7 is disposed on the inner side of the case 5 in a state where the first sealing body element 7 is on the lower surface side and the second sealing body element is on the upper surface side. The sealing body is arranged so that the second sealing body element is on the outer surface, the electrode terminal 2 is fitted into the electrode terminal insertion hole 9 of the sealing body 6, and the sealing body 6 is provided in the opening 51 of the case 5. Next, the tip of the opening edge 52 is brought into pressure contact with the outer surface of the second sealing element 8 of the sealing body 6 in the height direction, and the inner peripheral surface 53 of the opening edge 52 is connected to the first surface of the sealing body 6. The sealing element 7 is pressed against the outer peripheral surface 71 in the radial direction. In this way, by crimping the opening edge 52 of the case 5, the sealing body 6 having the electrode terminal 2 is hermetically provided in the opening 51 of the case 5, and the opening 51 of the case 5 is sealed. Electrolytic capacitors are provided. In this case, the thin film layer 12 may be formed on the outer peripheral surface 71 of the first sealing body element 7. If the thin film layer 12 is formed on the outer peripheral surface 71 of the first sealing body element 7, the opening end edge 52 of the case 5 is caulked and the inner peripheral surface 53 of the opening end edge 52 is the second end of the sealing body 6. When the outer peripheral surface 71 of one sealing body element 7 is pressed in the radial direction, the inner peripheral surface 53 of the opening edge 52 and the outer peripheral surface 71 of the first sealing body element 7 of the sealing body 6 are thin film layers 12. Thus, the inner peripheral surface 53 of the opening edge 52 of the case 5 and the outer peripheral surface 71 of the first sealing element 7 of the sealing body 6 are more tightly bonded.

  Thus, the electrolyte solution 3 that has permeated from the first sealing element 7 is prevented from leaking out by the second sealing element 8, and the first sealing element 7 and the second sealing element are further prevented. Since the element 8 is tightly bonded, even if the electrolytic solution 3 that has permeated from the first sealing element 7 attempts to permeate the second sealing element 8, the first sealing element 7 and the second sealing element 7 It is possible to prevent the electrolyte solution 3 from leaking from the portion where the sealing body element 8 is joined. Further, since the second sealing element 8 is tightly joined to the first sealing element 7 to constitute the outer surface of the sealing element 6, even if the first sealing element 7 is made of silicon rubber. When the opening edge 52 of the case 5 is caulked, the first sealing body element 7 is not damaged at the tip of the opening edge 52, and the electrolytic capacitor has a high temperature atmosphere of about 150 ° C. Even when used underneath, the sealing body 6 is less likely to be thermally deteriorated, and the cause of the electrolyte solution 3 leaking or evaporating from the sealing body 6 using a rubber material is eliminated. The lifetime can be extended.

  When the opening 51 of the case 5 is sealed with the sealing body 6, the electrode terminal 2 including the pair of lead terminals 21 and 22 electrically connected to the pair of anode and cathode plates 4 of the capacitor element 1 is sealed. By being inserted into the pair of electrode terminal insertion holes 9 of the body 6, the body 6 is provided in an airtight manner and protrudes or is exposed to the outside of the case 5. In this case, the thin film layer 12 may be formed on the inner peripheral surface of the first insertion hole 10 or the second insertion hole 11 of the pair of electrode terminal insertion holes 9. By forming the thin film layer 12 on the inner peripheral surface of the first insertion hole 10 or the second insertion hole 11, the inner peripheral surface of the first insertion hole 10 or the second insertion hole 11, the electrode terminal 2, and Is pressed through the thin film layer 12, and the electrode terminal 2 is more tightly fitted into the electrode terminal insertion hole 9, so that the electrolytic solution 3 is removed from the gap between the electrode terminal 2 and the electrode terminal insertion hole 9. It can be prevented from leaking or evaporating. Moreover, although not shown in figure, the electrolyte solution 3 is an electrode by filling the insertion part of the sealing body 6 and the electrode terminal 2 with the sealing agent which has pitches, such as coal tar pitch and asphalt pitch, as a main component, for example. It is possible to further improve the airtightness of the electrode terminal 2 to the electrode terminal insertion hole 9 so as not to leak or evaporate from the gap between the terminal 2 and the electrode terminal insertion hole 9.

  Similarly, the edge of the opening of the case 5 can be obtained by filling the caulking part between the sealing body 6 and the case 5 with a sealant mainly composed of a pitch such as coal tar pitch or asphalt pitch. In the electrolytic capacitor in which the opening 51 of the case 5 is sealed by crimping 52, an electrolytic capacitor with further improved airtightness can be obtained.

  The shape of the electrolytic capacitor sealing body 6 of the present invention is exemplified by a cylindrical shape, but the cross-sectional shape is not limited to a perfect circle, and is determined by the shape of the electrolytic capacitor case. If the cross-sectional shape of the case is a cylindrical body formed into an oval shape, the first sealing body element 7 and the second sealing body element 8 have a columnar shape with a cross-sectional shape formed into an oval shape, respectively. The shape of the sealing body 6 is plate-like, and the cross-sectional shape is an ellipse.

  The electrolytic capacitor sealing body and the electrolytic capacitor using the sealing body of the present invention are effective for electrical equipment, electronic equipment, or telecommunications equipment having a high operating environment temperature.

2 Electrode terminal 5 Case 6 Sealing body (or sealing body for electrolytic capacitor)
7 First sealing element 8 Second sealing element 9 A pair of electrode terminal insertion holes 10 First insertion hole 11 Second insertion hole 12 Thin film layer 51 Opening 52 Opening edge

Claims (2)

  A sealing body for an electrolytic capacitor having an insertion hole for an electrode terminal, the first sealing body element having a first insertion hole and formed in a cylindrical shape made of silicon rubber, and a second insertion hole. A mercapto group, a thiocarbonyl group, a cyano group, an isocyanate group, an amino group, an ammonium group on any one of the surfaces to be joined to the second sealing element formed into a disk shape made of a thermoplastic resin. , A pyridinium group, an azinyl group, a carboxyl group, a benzotriazole group, a triazine thiol group, etc. The first sealing body element and the second sealing body element are pressurized at least in a state where the first sealing body element and the second sealing body element are polymerized through the thin film layer by communicating with the insertion hole of the first sealing body element. Tightly bonded Sealing member for an electrolytic capacitor, characterized in that by forming a through hole for the electrode terminal Te.   An electrolytic capacitor formed by closing an opening of a cylindrical case containing a capacitor element and an electrolytic solution with the sealing body for an electrolytic capacitor according to claim 1, wherein the first sealing body element is the The sealing body is arranged so that the second sealing body element becomes the outer surface on the inner side of the case, and the electrode terminal is hermetically provided in the electrode terminal insertion hole of the sealing body, and the opening edge of the case is provided. The tip of the edge of the opening crimps the outer surface of the second sealing element in the height direction, and the inner peripheral surface of the edge of the opening presses the outer peripheral surface of the first sealing element in the radial direction. By doing so, the said sealing body is airtightly provided in the opening part of a case, and the opening part of a case is sealed, The electrolytic capacitor characterized by the above-mentioned.

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