JPH08306596A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE: To provide a reliable electrolytic capacitor with good alkali-proof characteristics and small transmittance in electrolytic solution, in which liquid spill is prevented completely even when a driving electrolytic solution of quaternary salt is used. CONSTITUTION: An electrolytic capacitor comprises a capacitor element 1 impregnated with a GBL-based electrolytic solution made of quaternary salt as a solute, a case 2 with an opening part, a sealing member 3 for sealing the opening part, and a lead member 4 connected with the capacitor element 1. The sealing member 3 includes two rubber layers 31 made of IIR monomer and a resin layer 32 made of simple polypropylene between these rubber layers 31, and the volume of polypropylene is 80% of the sealing member 3. The sealing member 3 has a through hole 33 smaller than the lead member 4 so that the lead member 4 is passed in the through hole 33. In addition, a step part 23 projected inward is formed in the vicinity of the opening part of the case 2, and the sealing member 3 is put on the step part 23.

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 technique for improving a sealing structure for sealing an opening of a case.

[0002]

2. Description of the Related Art Generally, an electrolytic capacitor is constructed by housing a capacitor element impregnated with a driving electrolytic solution in a case having an opening, and sealing the opening with a sealing member. FIG. 11 is a diagram showing an example of such an electrolytic capacitor. As shown in FIG. 11, the electrolytic capacitor includes a wound capacitor element 1, a cylindrical metal case 2 having an opening at the top, a sealing member 3 for sealing the opening of the case 2, and a capacitor element. It is composed of a pair of lead members 4 connected to 1.

That is, in FIG. 11, the capacitor element 1 is formed by winding a pair of electrode foils with a spacer interposed therebetween. The capacitor element 1 is housed in a case 2 in a state of being impregnated with a driving electrolytic solution. The sealing member 3 is attached to the pair of lead members 4 connected to the capacitor element 1 such that the lead member 4 penetrates the sealing member 3.

In the state where the capacitor element 1 is housed in this way, the opening at the upper part of the case 2 is closed by the sealing member 3. In this case, a ring portion 21 protruding inward is formed on a part of the case 2 that contacts the side surface of the sealing member 3. With this ring portion 21,
The adhesion between the side surface of the sealing member 3 and the inner surface of the case 2 is enhanced, and the airtightness of the opening of the case 2 is ensured.
Further, the upper open end of the case 2 is curled inward, and the curled portion 22 bites into the edge of the sealing member 3,
The curl portion 22 further enhances the airtightness of the opening of the case 2.

In the electrolytic capacitor thus constructed, the inner space of the case 2 can be shielded from the outside air by sealing the opening of the case 2 accommodating the capacitor element 1 with the sealing member 3. In addition, at the penetrating portion of the lead member 4 in the sealing member 3, the sealing member 3 comes into close contact with the lead member 4 due to the elasticity of the sealing member 3, so that airtightness is secured by this close contact force. That is, as a result, it is possible to prevent the deterioration of the capacitor element 1 and the driving electrolyte in the case 2 due to the influence of outside air such as humidity, and thus there is an advantage of excellent reliability.

Conventionally, as a material of the sealing member 3 of such an electrolytic capacitor, ethylene propylene terpolymer (EPDM) or isobutylene isoprene rubber (II
R: popularly called butyl rubber) is used. In particular, IIR is used as the material of the sealing member 3 in an electrolytic capacitor that uses a γ-butyrolactone (GBL) -based electrolytic solution as the electrolytic solution. In this way, the sealing member 3
When IIR is used as the material, there is an advantage that the permeation amount of the electrolytic solution is small and the life can be extended. Further, at present, a quaternary salt is mainly used as a solute of the γ-butyrolactone electrolyte.

[0007]

However, the conventional electrolytic capacitor as described above has the following problems.

When isobutylene isoprene rubber (IIR) is used as the material of the sealing member 3 of the electrolytic capacitor using the γ-butyrolactone type electrolytic solution containing a quaternary salt as a solute, there is a problem that the sealing member 3 deteriorates. That is,
In an electrolytic capacitor using a γ-butyrolactone-based electrolytic solution containing a quaternary salt as a solute, when a DC voltage is applied, an electrochemical reaction occurs between the electrodes inside the electrolytic capacitor, the pH on the cathode side rises, and it becomes strongly alkaline. May be. The electrolytic solution having a strong alkalinity acts on the isobutylene isoprene rubber (IIR) that constitutes the sealing member 3 and deteriorates it, causing a decrease in the hardness of the rubber and corrosion of the rubber surface. As a result, the adhesion of the deteriorated sealing member 3 to the lead member 4 is weakened, and the airtightness between the sealing member 3 and the lead member 4 is reduced, so that the electrolytic solution leaks out from this portion.

The problem of such electrolyte leakage is as follows.
The problem is not limited to the electrolytic capacitor shown in FIG. 11, but is similarly present in various electrolytic capacitors configured so that the lead member 4 of the capacitor element 1 penetrates the sealing member 3. For example, in addition to the first lead member connected to the capacitor element 1, the sealing member 3 is provided with a second lead member in advance, and an electrolytic capacitor of a type in which these lead members are connected to each other is also strongly alkaline. When the sealing member 3 is deteriorated by the deteriorated electrolytic solution, the airtightness between the deteriorated sealing member 3 and the second lead member is reduced, and the electrolytic solution leaks out from this portion.

The present invention has been proposed to solve the above-mentioned problems of the prior art, and its purpose is to:
By improving the sealing member, the amount of electrolyte permeation is small, it has excellent alkali resistance, and even when a driving electrolyte containing a quaternary salt as a solute is used, it is possible to completely prevent leakage of the electrolyte. To provide a high electrolytic capacitor.

[0011]

An electrolytic capacitor of the present invention is a capacitor element impregnated with a driving electrolytic solution, a case having an opening for accommodating the capacitor element, and the opening of the case is sealed. An electrolytic capacitor having a sealing member and a lead member connected to the capacitor element, the lead member penetrating the sealing member is characterized by having the following configuration.

The electrolytic capacitor according to the first to fifth aspects is characterized in that the sealing member is constructed as follows.
In the electrolytic capacitor according to the first aspect, the sealing member is made of a rubber material and a resin material, and the ratio of the resin material to the volume of the sealing member is 10 to 99%. In the electrolytic capacitor of the second aspect, the resin material is one or more kinds of materials selected from polypropylene, polyphenylene sulfide, polyimide, polyamide, and fluororesin. In the electrolytic capacitor according to claim 3, the rubber material is at least one material selected from ethylene propylene terpolymer (EPDM), isobutylene isoprene rubber (IIR), and butadiene styrene rubber (SBR). In the electrolytic capacitor according to claim 4, the sealing member is configured such that the resin material is present on the contact surface of the penetrating portion of the lead member with the lead member. The electrolytic capacitor according to claim 5, wherein the sealing member is configured such that a diameter of a penetrating portion of the lead member is smaller than a diameter of the lead member.

An electrolytic capacitor according to a sixth aspect of the invention is characterized in that a sealing structure including a sealing member is constructed as follows. That is, in the electrolytic capacitor according to the sixth aspect, the case has a step portion formed in the vicinity of the opening and protruding inward. Then, the sealing member is arranged on the stepped portion of the case.

An electrolytic capacitor according to a seventh aspect is characterized in that a γ-butyrolactone (GBL) -based electrolytic solution containing a quaternary salt as a solute is used as a driving electrolytic solution.

[0015]

In the present invention having the above structure,
The following effects are obtained. First, in the invention according to claims 1 to 3, the sealing member is ethylene propylene terpolymer (EPDM), isobutylene isoprene rubber (I
IR) or butadiene styrene rubber (SBR), etc., and not such a rubber material alone, but such a rubber material and a resin having high alkali resistance such as polypropylene, polyphenylene sulfide, polyimide, polyamide, or a fluorine resin. It is constructed by combining materials. As described above, the sealing member made of the rubber material and the resin material has excellent alkali resistance as compared with the sealing member made of the conventional isobutylene isoprene rubber (IIR) alone.
Therefore, such a sealing member of the present invention is claimed in claim 7.
As described above, even when it is combined with a driving electrolytic solution containing a quaternary salt as a solute, it is stable without causing a decrease in hardness or surface erosion due to the electrolytic solution becoming strongly alkaline. And such an effect is remarkably obtained when the ratio of the resin material is 10 to 99% of the volume of the sealing member.

According to the fourth aspect of the present invention, the presence of the resin material in the penetrating portion of the lead member of the sealing member can increase the alkali resistance of the sealing member in this portion. Therefore, even if such a penetrating portion having excellent alkali resistance is combined with a driving electrolyte solution containing a quaternary salt as a solute as described in claim 7, the hardness decreases due to the electrolytic solution becoming strongly alkaline. It is stable without erosion or surface erosion. Therefore, the airtightness between the sealing member and the lead member can be maintained.

According to the invention of claim 5, the diameter of the penetrating portion of the lead member of the sealing member is made smaller than the diameter of the lead member, so that the airtightness between the sealing member and the lead member is improved. Can be higher. In this case, when attaching the lead member to the sealing member, the elasticity of the sealing member is used to push the lead member into the penetrating portion.

Further, according to the invention of claim 6, a step portion projecting inward is provided in the vicinity of the opening of the case, and the sealing member is arranged on the step portion, whereby the case and the sealing member are separated from each other. High airtightness can be secured in the meantime. That is, in such a configuration, by pushing the sealing member into the case, not only the side surface of the sealing member is in close contact with the inner surface of the case, but the bottom surface of the sealing member is in close contact with the upper surface of the step portion, A contact surface having an L-shaped cross section is formed, and high airtightness can be ensured between the case and the sealing member.

On the other hand, by increasing the proportion of the resin material in the sealing member, it is possible to reduce the amount of permeation of the electrolytic solution, which is greatly related to the life of the electrolytic capacitor. In this case, the overall thickness of the sealing member can be reduced, so that the electrolytic capacitor can be downsized.

[0020]

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

[1] Structure of sealing member ... FIG. 1 First, as a rubber material and a resin material, isobutylene isoprene rubber (IIR) alone and polypropylene alone are combined, and the ratio of polypropylene is 10 to 9 of the volume of the sealing member.
A sealing member 3 having a laminated structure including two rubber layers 31 and a resin layer 32 sandwiched between the rubber layers 31 as shown in FIG. In this case, the sealing member 3 is configured such that the resin material is present on the contact surface of the penetrating portion 33 of the lead member 4 with the lead member 4. The diameter of the penetrating portion 33 of the sealing member 3 is smaller than that of the lead member 4. At the same time, the sealing member was composed of IIR alone and polypropylene alone, and these were made into two comparative examples.

[2] Action and Effect of Sealing Member ... FIGS. 2 to 5 [2-1] Action and Effect of Sealing Member of Comparative Example ... FIGS. 2 and 3 First, FIG. 2 shows IIR alone and polypropylene alone. The result of having measured the permeation amount of the γ-butyrolactone (GBL) -based electrolytic solution with respect to each of the configured two sealing members which are comparative examples is shown. Here, the test conditions are both 10
It is 5 ° C. and 200 hours (h). As is clear from FIG. 2, in the case of the sealing member made of polypropylene alone, the permeation amount of the γ-butyrolactone (GBL) -based electrolytic solution is smaller than that of the sealing member made of only IIR, and the life can be extended. Benefits are obtained.

Next, FIG. 3 shows the results of measuring the hardness of each sealing member with time by immersing each sealing member, which is two comparative examples composed of IIR alone and polypropylene alone, in an alkaline solution. There is. Here, the conditions of the alkaline solution are pH 12 and 105 ° C., and the immersion time is 200 hours (h). As is clear from FIG. 3, when polypropylene is used alone, there is no change in hardness in the alkaline solution, and it is possible to obtain extremely excellent alkali resistance as compared with IIR.

[2-2] Operation and effect of the sealing member of the present embodiment ... FIGS. 4 and 5 Based on the operation and effect of the comparative example as described above, II
Rubber layer 31 such as R and resin layer 32 such as polypropylene
According to the sealing member 3 of the present embodiment configured from, the electrolyte permeation amount can be reduced and the life can be extended,
It becomes possible to greatly improve the alkali resistance. Particularly, in the sealing member 3 of the present embodiment, the diameter of the penetrating portion 33 is smaller than the diameter of the lead member 4, so that the airtightness between the sealing member 3 and the lead member 4 is high. Moreover, since the resin material is present on the contact surface of the penetrating portion 33 of the lead member 4 with the lead member 4, the alkali resistance of this portion is high.

Therefore, in the electrolytic capacitor using the sealing member 3 of the present embodiment and using the γ-butyrolactone (GBL) -based electrolytic solution containing a quaternary salt as a solute as the electrolytic solution, the electrolytic solution becomes strongly alkaline. Even in the case of becoming unsealed, the high airtightness between the sealing member 3 and the lead member 4 can be maintained, and the leakage of the electrolytic solution from this portion can be prevented. As a result, the life of the electrolytic capacitor can be further extended.

Further, FIG. 4 shows the γ-butyrolactone (GBL) type electrolytic solution of the sealing member 3 of this embodiment in which the volume ratio of polypropylene in the sealing member 3 is continuously changed under the condition of 105 ° C. The results of examining the relationship between the polypropylene volume ratio and the amount of permeation after 200 hours have been shown. As is clear from FIG. 4, when the volume ratio of polypropylene is 10% or more, the permeation amount is almost equal to that of the sealing member made of polypropylene alone, and a sufficient effect is exhibited.

On the other hand, FIG. 5 shows that the sealing member 3 of this embodiment in which the volume ratio of polypropylene in the sealing member 3 was continuously changed was immersed in an alkaline solution of pH 12 and 105 ° C., and after 200 hours had elapsed. The result of examining the relationship between the polypropylene volume ratio and the rate of change in hardness is shown. As is clear from FIG. 5, the volume ratio of polypropylene is 10%.
In the above case, the hardness change rate is reduced to about 2% or less. Therefore, it can be seen that when the volume ratio of polypropylene is 10% or more, sufficient alkali resistance can be obtained.

The volume ratio of polypropylene is 100
When it is set to%, the elasticity of the sealing member 3 becomes weak and the airtightness is lowered. Therefore, it is necessary to secure the airtightness by the elasticity of the rubber material by setting the volume ratio of polypropylene to 99% or less and using at least 1% or more of the rubber material. Therefore,
When the volume ratio of polypropylene is in the range of 10 to 99%, the permeation amount of the electrolytic solution, alkali resistance,
And the same excellent effect can be obtained for all of the airtightness.

[3] Structure of electrolytic capacitor: FIG. 1 Further, based on the above results, IIR and polypropylene were combined and the volume ratio of polypropylene was 8%.
The sealing member 3 having a three-layer structure as shown in FIG. Then, using this sealing member 3, a rating of 2
5V-1000μF, case size φ12 × 20 (m
The electrolytic capacitor of m) was actually manufactured with the structure as shown in FIG. 1, and this was used as the electrolytic capacitor of this example.

That is, as shown in FIG. 1, first, in the vicinity of the opening of the case 2, below the portion where the sealing member 3 is disposed, a step 23 protruding inward is formed. Next, in this case 2, the capacitor element 1 impregnated with a γ-butyrolactone (GBL) -based electrolytic solution containing a quaternary salt as a solute was housed. The sealing member 3 was attached to the pair of lead members 4 connected to the capacitor element 1 in such a manner that the lead members 4 were inserted into the penetrating portions 33 of the sealing member 3. Subsequently, after the sealing member 3 is arranged on the stepped portion 23 of the case 2, the upper open end of the case 2 is curled inward, and the curled portion 22 is bitten into the edge of the sealing member 3 to electrolytic capacitor. Was completed. At the same time, an electrolytic capacitor having the same structure except for the sealing member was produced by using the sealing member composed of a single IIR, which was used as a comparative example (conventional example).

Table 1 below summarizes the conditions of the electrolytic capacitors of this embodiment and the conventional example.

[0032]

[Table 1]

[4] Action and effect of electrolytic capacitor ... FIG. 6
8 [4-1] High airtightness from the shape surface In the electrolytic capacitor of this example produced under the above conditions, as described above, the penetrating portion 33 of the sealing member 3 is used.
Since the diameter of is smaller than the diameter of the lead member 4,
The airtightness between the sealing member 3 and the lead member 4 is high. Further, since the sealing member 3 is arranged on the stepped portion 23 of the case 2, by pushing the sealing member 3 into the case 2, the adhesion between the side surface of the sealing member 3 and the inner surface of the case 2 is improved. In addition to being able to ensure, the adhesion between the bottom surface of the sealing member 3 and the top surface of the step portion 23 can be ensured. That is, as shown in FIG. 1, a contact surface having an L-shaped cross section is formed between the sealing member 3 and the case 2, whereby high airtightness is secured.

[4-2] Permeation amount of electrolytic solution ... FIG. 6 FIG. 6 shows the results of measuring the permeation amount of electrolytic solution with time for the electrolytic capacitors of the present example and the conventional example manufactured under the above conditions. Shows. Here, the test conditions are both 1
It is 05 degreeC and 200 hours (h). As is clear from FIG. 6, in the present embodiment in which the sealing member configured by combining IIR and polypropylene and having a volume ratio of polypropylene of 80% was used, the sealing member configured by a single IIR was used. It is possible to significantly reduce the amount of electrolyte permeation compared to the example. Further, the high airtightness from the above-mentioned shape surface also helps to reduce the permeation amount of the electrolytic solution. As a result, the life of the electrolytic capacitor can be extended.

[4-3] Alkali resistance ... FIG. 7 FIG. 7 shows the hardness of the sealing members by immersing the sealing members of the electrolytic capacitors of the present example and the conventional example manufactured under the above conditions in an alkaline solution. The results measured over time are shown. The conditions of the alkaline solution in FIG. 7 are pH 12, 10
It is 5 degreeC and immersion time is 200 hours (h).

As can be seen from FIG. 7, in the present embodiment in which the sealing member constituted by combining IIR and polypropylene and having a polypropylene volume ratio of 80% was used, the sealing member constituted by IIR alone was used. In comparison, a significantly higher hardness can be obtained, and the hardness does not decrease. Therefore, in the sealing member of the present embodiment, II
Compared with a sealing member made of R alone, much higher alkali resistance is obtained, and the initial high hardness is maintained even when exposed to alkali.

That is, since the hardness of the sealing member made of only IIR changes in the alkaline solution, as described above, γ-butyrolactone (G
When the cathode side becomes strongly alkaline when a DC voltage is applied to an electrolytic capacitor using a BL) type electrolytic solution, the strongly alkaline electrolytic solution deteriorates the sealing member and reduces the airtightness between the sealing member and the lead member. The electrolyte leaks out from the part.

On the other hand, in the sealing member of this embodiment, which is composed of IIR and polypropylene in combination and the volume ratio of polypropylene is 80%, the sealing member is not deteriorated even by the strong alkaline electrolyte. Since the high airtightness between the sealing member and the lead member can be maintained, it is possible to prevent the electrolytic solution from leaking from this portion.

[4-4] Capacitor Performance ... FIG. 8 FIG. 8 shows the results of evaluation of the performance of the electrolytic capacitors of the present example and the conventional example produced under the above conditions.
Here, FIG. 8 shows that the electrolytic capacitors of the present example and the conventional example were left under a condition of 105 ° C. for a long time, and the electrolytic solution permeation amount Δw, the capacitance change rate ΔC, and tan δ were changed with time. The measurement results are shown in. As can be seen from FIG. 10, in this embodiment, the electrolytic solution permeation amount of the electrolytic capacitor is smaller than that in the conventional example, and the capacitance,
The change in tan δ is also smaller than in the conventional example. Such a difference in the rate of change is particularly remarkable after 1000 hours (h) have elapsed. From this, it is clear that the electrolytic capacitor of this embodiment has a much longer life than the conventional example.

Further, Table 2 below shows 85 ° C. and 85 ° C. for each of 10 samples of electrolytic capacitors of this example and the conventional example.
Number of liquid leaks after 250 hours (h), 500 hours (h), 1000 hours (h), and 2000 hours (h) when the rated DC voltage was applied in% RH Are shown respectively. As shown in Table 2, in the conventional example, after the lapse of 200 hours (h), as many as 5 out of 10 liquid leaks occurred, but in the present example, no liquid leak occurred. Therefore, according to the present example, γ-butyrolactone (G
In the electrolytic capacitor using the BL) type electrolytic solution, the reliability can be significantly improved as compared with the conventional example.

[0041]

[Table 2]

[5] Other Embodiments FIG. 9, FIG. 10 The present invention is not limited to the above-mentioned embodiment,
For example, as the resin material used for the sealing member, in addition to polypropylene, polyphenylene sulfide, polyimide, polyamide, fluorine resin, or the like can be used. In this case, it is possible to use only one kind of resin material, but it is also possible to appropriately select and use two or more kinds of resin materials, and in any case, it is almost the same as the above embodiment. The action and effect of can be obtained.

Further, in the above embodiment, the case where the volume ratio of polypropylene as the resin material is set to 80% has been described, but in the present invention, the volume ratio of the resin material to the entire sealing member is 10 to 99%. It is possible to select between them, and as long as it is selected within this range, it is possible to obtain substantially the same operation and effect as the above-mentioned embodiment.

As the rubber material used for the sealing member, ethylene propylene terpolymer (EPDM), butadiene styrene rubber (SBR), etc. can be used in addition to IIR. In this case, it is possible to use only one kind of rubber material, but it is also possible to appropriately select and use two or more kinds of rubber material, and in any case, it is almost the same as the above embodiment. The action and effect of can be obtained.

On the other hand, with respect to the structure of the sealing member, various structures as shown in FIG. 9 are possible in addition to the above embodiment. In FIG. 9, (a) is a structure in which the rubber layer 31 and the resin layer 32 are arranged vertically, (b) is a structure in which (a) is turned upside down, and (c) is a side surface of the resin layer 32. This is a structure in which a rubber layer 31 is arranged around the periphery. (D) shows the resin layer 32
A structure in which a rubber layer 31 is arranged around the side surface and the upper surface of the
(E) shows the rubber layer 3 around the side surface and the lower surface of the resin layer 32.
1 is a structure in which 1 is arranged, and (f) is a structure in which the rubber layer 31 is arranged so as to cover the entire side surface and upper and lower surfaces of the resin layer 32. In either structure, the penetrating portion 33 of the sealing member 3
Since the resin material is present on the contact surface with the lead member 4 in, the same operation and effect as in the above-described embodiment can be obtained.

Further, as for the sealing structure including the sealing member for the case opening, various structures as shown in FIG. 10 are possible in addition to the above embodiment. In this FIG.
11A shows a structure in which a ring portion 21 protruding inward is formed in a part of the case 2 that contacts the side surface of the sealing member 3, as in the conventional example of FIG. 11, and FIG. In this structure, the thickness below the portion where the sealing member 3 is arranged is thickened inward to form the step portion 23, and the sealing member 3 is disposed on the step portion 23. In any structure, the airtightness can be maintained as in the above-described embodiment, and the same operation and effect as those in the above-described embodiment can be obtained. However, in the structure of (a), an extra force for overcoming the ring portion 21 is required for mounting the case 2 of the sealing member 3, and in the structure of (b), the thickness of the case 2 is partially increased. Need to change to. Therefore, from the viewpoint of workability and productivity, it can be said that the structure of the above embodiment is superior.

On the other hand, in the present invention, γ-containing a quaternary salt as a solute
It is also possible to use a driving electrolytic solution other than the butyrolactone (GBL) -based electrolytic solution. Also, the rating of the electrolytic capacitor to which the present invention is applied can be freely selected.

[0048]

As described above, according to the present invention,
By using a sealing member composed of a rubber material and a resin material, the amount of electrolyte permeation is small, and it has excellent alkali resistance,
It is possible to provide a highly reliable electrolytic capacitor that can completely prevent leakage of the electrolytic solution even when a driving electrolytic solution containing a quaternary salt as a solute is used.

[Brief description of drawings]

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

FIG. 2 is a graph showing the amount of electrolyte permeation with time of each sealing member composed of a single IIR and a single polypropylene.

FIG. 3 is a graph showing a change with time in hardness of each sealing member made of IIR alone and polypropylene alone in an alkaline solution.

FIG. 4 is a graph showing the relationship between the polypropylene volume ratio and the electrolyte permeation amount of the sealing member according to the present invention.

FIG. 5 is a graph showing the relationship between the polypropylene volume ratio of the sealing member according to the present invention and the hardness change rate in an alkaline solution.

6 is a graph showing the electrolytic solution permeation amount over time for the electrolytic capacitor of the example of FIG. 1 and the electrolytic capacitor of the conventional example.

FIG. 7 is a graph showing the change over time in hardness of the sealing member in an alkaline solution for the electrolytic capacitor of the example of FIG. 1 and the electrolytic capacitor of the conventional example.

8 is a graph showing changes over time in the electrolytic solution permeation amount Δw, the capacitance change rate ΔC, and tan δ for the electrolytic capacitor of the example of FIG. 1 and the electrolytic capacitor of the conventional example.

FIG. 9 is a schematic cross-sectional view showing another embodiment of the sealing member according to the present invention.

FIG. 10 is a schematic cross-sectional view showing another embodiment of the case opening sealing structure according to the present invention.

FIG. 11 is a schematic cross-sectional view showing an example of a conventional electrolytic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Capacitor element 2 ... Case 3 ... Sealing member 4 ... Lead member 21 ... Ring part 22 ... Curl part 23 ... Step part 31 ... Rubber layer 32 ... Resin layer 33 ... Penetration part

Claims (7)

[Claims] 1. A capacitor element impregnated with a driving electrolytic solution, a case having an opening for accommodating the capacitor element, and a sealing member for sealing the opening of the case,
And a lead member connected to the capacitor element, wherein the lead member is configured to penetrate the sealing member, the sealing member is composed of a rubber material and a resin material, The electrolytic capacitor is characterized in that the proportion of the resin material in the volume is 10 to 99%. 2. The electrolytic capacitor according to claim 1, wherein the resin material is one or more kinds of materials selected from polypropylene, polyphenylene sulfide, polyimide, polyamide, and fluorine resin. 3. The rubber material is one or more kinds of materials selected from ethylene propylene terpolymer (EPDM), isobutylene isoprene rubber (IIR), and butadiene styrene rubber (SBR). The electrolytic capacitor according to claim 1. 4. The electrolytic capacitor according to claim 1, wherein the sealing member is configured such that a resin material is present on a contact surface of the penetrating portion of the lead member with the lead member. 5. The electrolytic capacitor according to claim 1, wherein the sealing member is configured such that a diameter of a penetrating portion of the lead member is smaller than a diameter of the lead member. 6. The case has an inwardly projecting step formed in the vicinity of an opening of the case, and the sealing member is disposed on the step of the case. 1. The electrolytic capacitor described in 1. 7. The electrolytic capacitor according to claim 1, wherein a γ-butyrolactone-based electrolytic solution containing a quaternary salt as a solute is used as the driving electrolytic solution.