JP6739027B2 - Breathable packing blocks - Google Patents

Description

The present invention relates to a breathable packing that makes it difficult for water to pass therethrough and allows gas to pass therethrough easily.

Gas is generated inside, and when the temperature rises, gas is actively generated and the pressure in the closed container increases due to the generated gas.In the closed container, the pressure in the closed container causes the closed container to expand, The closed container may burst. Gas is generated in such an inside, and when the temperature of the sealed container becomes high, the gas is actively generated, and the pressure in the sealed container rises due to the generated gas, for example, a capacitor having an electrolytic solution or lithium. In sealed electrochemical devices such as batteries, the electrolyte is sealed so that it does not leak out of the sealed container.Therefore, repeat charge/discharge cycles, leave at high temperature, short circuit, overcharge, reverse The electrolytic solution is decomposed by charging, and gas such as hydrogen gas and carbon dioxide gas is generated in the sealed container, and the gas is accumulated in the sealed container, so that the internal pressure rapidly rises and the sealed container is closed. Since there is a risk that the gas will expand or burst, a breathable packing that appropriately discharges the generated gas to the outside of the closed container so that the generated gas does not accumulate too much in the closed container is desired. Further, even in the lithium battery sealed housing a solid electrolyte in a sealed container in place of the electrolytic solution, since the sealed container is so as not to transmit moisture and gas from outside and contained in the solid electrolyte in the closed container Since the solvent gas is generated and the gas is accumulated in the closed container, the internal pressure rises abruptly, and the closed container may expand or burst. There is a demand for a breathable packing that appropriately discharges the generated gas to the outside of the closed container so as not to accumulate too much inside.

It is effective in preventing the rupture of a container whose contents are liquid or solid gas is generated, and the liquid impermeability and breathability are not impaired for a long period of time even when the container falls over and is wet by the contents that are liquid. In addition, as a breathable packing in which the contents do not leak out, a packing base material made of polyolefin in which a microporous film made of polyolefin having an intrinsic viscosity of 3 dl/g or more is formed in a gas passage is disclosed in Patent Document 1. Ventilation that allows the generated gas to escape but prevents the liquid or solid from leaking when it is used for packing the cap of a container containing a liquid or solid that generates gas, by sticking it on at least one side of Sex packing is suggested.

However, in the air-permeable packing of Patent Document 1, the microporous film laminated on the packing base material made of polyolefin having a gas flow path has a porosity so as to balance liquid impermeability and air permeability, It is necessary to set the air permeability and average pore size.

Further, as a sealed electrochemical device such as a capacitor having an electrolytic solution or a lithium battery, in Patent Document 2, a through hole that penetrates the front and back is formed in a sealing plate of the electrolytic capacitor, and the through hole is formed by a foamed silicone rubber. By sealing with, the gas generated inside the electrolytic capacitor is permeated and released (exhausted) to the outside to mitigate the rise in internal pressure and delay the safety valve operation, aiming to improve the life characteristics of the electrolytic capacitor. Is proposed.

However, in the electrolytic capacitor of Patent Document 2, the foamed silicone rubber has a high gas permeability and does not allow the electrolytic solution to permeate, but the inside of the electrolytic capacitor generates gas due to a rapid temperature rise. It is necessary to consider that it will flourish. That is, it is necessary to consider that the safety valve operation of the electrolytic capacitor cannot be delayed unless the temperature of the electrolytic capacitor is increased and the gas is discharged to the outside of the electrolytic capacitor.

Further, in Patent Document 3, in order to prevent the deterioration of the discharge performance of the battery by lowering the airtightness inside the battery at high temperature and dissipating the gas generated inside the battery to the outside, the upper surface of the sealing gasket and the positive electrode terminal plate are There has been proposed a dry battery in which a paraffin-impregnated packing having a melting point of 40 to 45° C. is sandwiched between the lower surface and the lower surface of the peripheral portion to improve the liquid leakage resistance.

However, in Patent Document 3, the packing impregnated with paraffin at low temperature or normal temperature adheres well to the upper surface of the sealing gasket and the lower surface of the peripheral portion of the positive electrode terminal plate to have high airtightness, but at high temperature of 40° C. or higher, This paraffin melts and flows, and the adhesion between the packing and the upper surface of the sealing gasket and the lower surface of the peripheral portion of the positive electrode terminal plate is reduced, and the airtightness of this portion is reduced. As a result, the gas generated inside the battery is dissipated to the outside, but at this time, it is necessary to consider that the melted and fluidized paraffin does not flow out to the outside.

In Patent Document 4, a thin battery in which a solid electrolyte or a gel electrolyte is contained in a closed container instead of an electrolytic solution, and the closed container body is an exterior material made of a moisture-proof multilayer film including a resin layer and a metal foil layer, A thin battery such as a lithium battery sealed by heat fusion or an adhesive resin has been proposed. Due to this thin battery and its high energy density, in the unlikely event of an internal short circuit or destruction due to an external force, there is a risk that energy will be released in a short time and the battery will reach a high temperature. The vapor pressure of the solvent contained in the electrolyte increases, and the internal pressure of the battery becomes high due to the gas derived from the solvent. Therefore, when a cut is made in the resin layer inside the moisture-proof multilayer film and the internal pressure of the battery rises, this cut part tears and linearly breaks to discharge the gas in the battery and prevent the battery from bursting. It forms a safety valve.

However, in Patent Document 4, since the safety valve due to the opening of the exterior material is used, in order for the internal pressure of the battery to rise and the cut portion of the exterior material to tear, the internal pressure needs to rise as the exterior material expands. It is necessary to safely discharge the gas by managing the relationship between the internal pressure of the battery caused by the gas generation, the cleavage of the exterior material, and the gas discharge. In addition, the cleavage of the exterior material prevents the thin battery from performing its proper function.

JP, 2002-347821, A JP, 2001-15391, A Japanese Utility Model Publication No. 62-31369 JP, 11-125505, A

The present invention, in order to solve the above-mentioned problems, gas is generated inside, and when the temperature becomes high, the generation of gas becomes active and the pressure in the closed container increases due to the generated gas. An object of the present invention is to provide a breathable packing that uses a permeable base material and a low melting point element to make it difficult for water to permeate and to discharge the generated gas to the outside of a closed container.

The air-permeable packing block according to claim 1 of the present invention has a vent hole communicating with the inside and outside of the closed container body that constitutes the closed container, and gas is generated inside the closed container to generate gas when the temperature becomes high. Is used in a closed container in which the pressure in the closed container increases due to the generated gas, and the gas is discharged from the ventilation hole to the outside of the closed container in the process of increasing the pressure in the closed container. A breathable packing block , wherein the breathable packing block is a breathable packing obtained by dispersing low melting point elements inside a gas permeable substrate made of a material having fine holes or gaps through which moisture and gas pass. And a protective sheet that protects the melted low melting point element from scattering outside the sealed container body, the breathable packing is disposed inside the sealed container body, and the protective sheet is the ventilation member. And a gas bypass for separating the low melting point element without melting the low melting point element and closing the vent hole, and melting the low melting point element at a temperature equal to or higher than the melting point to allow the gas to pass therethrough. It is characterized in that it has a function of opening the vent hole due to generation of a passage and a function of preventing the melted low melting point element from scattering to the outside . The invention described in the claim 2, breathable packing block according to claim 1, the material of the previous SL gas permeable substrate is characterized in that a nonwoven fabric.

The air-permeable packing block of the present invention has a ventilation hole communicating with the inside and outside of the closed container body forming the closed container , gas is generated inside the closed container, and the gas is actively generated when the temperature becomes high. A gas permeable packing block that is used in a closed container in which the pressure in the closed container increases due to the generated gas, and that discharges the gas from the ventilation hole to the outside of the closed container in the process of increasing the pressure in the closed container. The breathable packing block includes a breathable packing formed by dispersing low melting point elements inside a gas permeable substrate made of a material having fine pores or gaps through which moisture and gas can pass, and a melted low melting point. The element is composed of a protective sheet that protects the airtight container from being scattered to the outside, the breathable packing is disposed inside the airtight container body, and the protective sheet is separated from the breathable packing. It is arranged so as to close the vent hole without melting the low melting point element and to generate the gas bypass passage for melting the low melting point element at a temperature equal to or higher than the melting point to allow gas to pass therethrough by the pressure of the gas. By providing a function with the state of opening the pores and a function of the molten low melting point element not scattering to the outside, it is possible to prevent the molten low melting point element from scattering to the outside, and usually the vent hole It is closed so that it is difficult for water to permeate and does not allow gas to permeate.When the temperature becomes high and gas is actively generated, the vent hole is opened through the gas bypass passage to accumulate gas in a closed container. The gas is discharged from the ventilation hole to the outside of the closed container so as not to be excessive, and when the temperature is lowered, the gas permeable substrate is returned to a state in which moisture and gas are not permeated by the low melting point element to close the ventilation hole. Can be made impermeable to moisture and gas.

It is an AA sectional view shown in Drawing 2 which expanded the composition of the air permeable packing used for the closed container body in Embodiment 1 of the present invention. FIG. 2 is a plan view of FIG. 1. FIG. 3 is a cross-sectional view showing a state in which the breathable packing is subjected to a temperature and pressure equal to or higher than a melting point according to the first embodiment of the present invention. It is sectional drawing which expanded the site|part of the low melting point element of the air permeable packing of this invention. FIG. 5 is a plan view of FIG. 4. It is sectional drawing of the experiment apparatus which fuses a low melting point element with the air permeable packing of this invention. It is a top view of the photograph which imaged the air permeable packing in the state which does not fuse|melt the low melting point element of this invention with the measuring microscope. It is a top view of the photograph which imaged the air permeable packing in the state where the low melting point element of the present invention was made to melt with a measuring microscope. It is sectional drawing which shows the sealed electrochemical device using the air permeable packing of this invention. It is a BB sectional view shown in Drawing 11 which expanded the composition of the air permeable packing used for the closed container body in Embodiment 2 of the present invention. It is a top view of FIG. It is CC sectional drawing shown in FIG. 13 which expanded the structure of the air permeable packing used for a closed container main body in Embodiment 3 of this invention. FIG. 13 is a plan view of FIG. 12. FIG. 9 is a cross-sectional view showing another embodiment of the sealed electrochemical device using the breathable packing according to the third embodiment of the present invention.

(Embodiment 1)
The configuration of the breathable packing will be described with reference to FIGS. 1 to 5.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a part of the closed container body, and the closed container body 1 is provided with ventilation holes 2 made of fine holes. The ventilation hole 2 is a hole having a circular cross section with a diameter of 0.5 to 100 μm that penetrates the inside and outside of the closed container body 1 and is formed so as to make it difficult for water to pass therethrough and allow gas to pass therethrough. In this case, the vent holes 2 may be set in combination with the air-permeable packing 3 so that it is difficult for water to permeate and gas can permeate. An air-permeable packing 3 is provided inside the closed container body 1 (lower surface in FIG. 1). This breathable packing 3 is made by dispersing low melting point elements 3A having a melting point of 40 to 120° C. inside a gas permeable base material. In this case, the gas permeable base material is a rectangular or circular sheet having a thickness of about 0.2 mm, which is a material having fine holes or gaps so that the upper surface and the lower surface communicate with each other, and moisture and gas are permeable. For example, it is a material such as a non-woven fabric made of a glass fiber material, a cloth, a film having fine perforations or single holes, and paper. The gas permeable base material is filled with the low melting point element 3A such as low molecular weight polyethylene wax, paraffin or low melting point olefin compound in the fine holes or gaps, and the low melting point element 3A is dispersed inside the gas permeable base material. There is. The breathable packing 3 thus formed is fixed to the bottom surface portion (bottom portion) 4B of the support body 4 made of a bottomed cylinder having one end open, so that the breathable packing 3 is supported by the support body 4. The bottom portion 4B is configured to form a space 4A inside the support body 4. The support 4 is formed in a cylindrical shape or a rectangular tube shape so that one end is opened and the bottom portion 4B at the other end is also opened and the breathable packing 3 is fixed to this bottom portion. Is made of a metal material or a synthetic resin material that is impermeable to moisture and gas. The support 4 is fixed to the inside (the lower surface in FIG. 1) of the closed container body 1 such that the air-permeable packing 3 communicates with the air hole 2 through the space 4A and is exposed. A protective sheet 5 is arranged inside the closed container body 1. The protective sheet 5 is made of a material similar to that of the gas permeable base material and has a rectangular or circular shape with a thickness of about 0.2 mm. In FIG. 1, the protective sheet 5 is the inside of the closed container body 1. It is fixed to (the lower surface in FIG. 1). As a result, it is shown that the open portion (open end) of one end of the support 4 is closed by the protective sheet 5. In this case, the protective sheet 5 may be fixed in advance so as to close the open end of the support 4, and the support 4 may be fixed together with the protective sheet 5 inside the closed container body 1. In this way, the breathable packing block 10 in which the breathable packing 3 is fixed to the inside of the closed container body 1 via the space 4A is obtained, and the breathable packing 3 has the low melting point element 3A inside the gas permeable base material. Are dispersed, so that the low melting point element 3A prevents moisture and gas from permeating. The protective sheet 5 is useful for protecting the melted low melting point element 3A from scattering from the ventilation hole 2 of the closed container body 1 to the outside .

Next, in FIG. 3, when the air-permeable packing 3 disposed inside the closed container body 1 receives a temperature and pressure P above the melting point in the closed container, the low melting point element 3A melts at a temperature above the melting point. Receiving the pressure P, the low melting point element removing portions 3B and 3C are formed on the upper surface and the lower surface of the gas permeable base material , respectively. As described above, the low-melting-point element removing portion 3B and the low-melting-point element removing portion 3C are formed by using the gas permeable base material made of a material that allows the upper surface and the lower surface to communicate with each other and allows moisture and gas to pass therethrough. Therefore, it is shown that the upper surface and the lower surface of the gas permeable base material are communicated with each other by receiving the temperature and pressure P equal to or higher than the melting point, and a gas bypass passage for allowing the gas to pass is generated inside the gas permeable base material. The breathable packing block 10 in which the pores 2 are opened is obtained.

FIGS. 4 and 5 are enlarged views of a part of the low melting point element 3A of the breathable packing 3 in FIG. 3 described above. When the breathable packing 3 receives a temperature and a pressure P above the melting point in the closed container. A state in which a part of the low melting point element 3A is in a molten state at a temperature and pressure equal to or higher than the melting point as described above, and the low melting point element removing parts 3B and 3C communicate with each other to generate a gas bypass passage inside the gas permeable base material. Indicates that

In FIG. 6, a polyphenylene sulfide (PPS) non-woven fabric is used as a material of a gas permeable base material that allows the upper surface and the lower surface to communicate with each other and allows moisture and gas to permeate, and the low melting point element 3A of paraffin wax is permeated into the gas permeable base material. An experimental apparatus for forming a low melting point element removing portion 3B and 3C by using a film having a thickness of 0.2 mm as the air permeable packing 3 and melting the low melting point element 3A of the air permeable packing 3 is shown. In this experimental apparatus, the temperature was set to 80° C. and the pressure P was set to 0.1 MPaG, and the heating/pressurizing air was sent from the lower surface to the upper surface, and the upper surface of the breathable packing 3 was measured by a measuring microscope (a The breathable packing 3 was observed using a Nikon measuring microscope MM-800)C.

FIG. 7 is a photograph obtained by observing the upper surface of the air-permeable packing 3 in a state in which the low melting point element 3A is not melted, and FIG. 8 is a view showing that the low melting point element 3A is melted and the low melting point element removing portion 3B is formed. It is a photograph figure obtained by observing the upper surface of breathable packing 3 in the formed state with a measuring microscope. In FIG. 8, it is possible to confirm the small-diameter low-melting-point element removal portion 3B which becomes the gas bypass passage at three places surrounded by the broken line circle on the upper surface of the air-permeable packing 3.

(Principle of moisture impermeable and gas permeable action of breathable packing)
1 to 5, the breathable packing is applied to a closed container body 1 having a vent hole 2 made of fine holes to make it difficult for water to permeate, and the breathable packing has fine holes or gaps. A gas permeable base material made of a material that allows the upper surface and the lower surface to communicate with each other and allows moisture and gas to permeate is used, and the low melting point element 3A is filled in the fine holes or gaps of the gas permeable base material. Since the low-melting point element 3A is dispersed inside the low-melting point element, the low-melting point element 3A blocks the fine holes or gaps of the gas permeable substrate to prevent moisture and gas from passing at a temperature at which the low-melting point element 3A does not melt, that is, at room temperature. The gas permeable base material acts as a gas barrier in such a manner that the gas permeable base material blocks the ventilation hole 2 of the closed container body 1 and makes it difficult for moisture and gas to permeate through the ventilation hole 2. Due to this action, the airtight container makes it difficult for moisture and gas to permeate at room temperature. Next, when the closed container body 1 reaches a melting temperature of the low melting point element 3A, that is, a high temperature, the low melting point element 3A becomes in a molten state, and the closing action of the low melting point element 3A becomes weak from the fine holes or gaps of the gas permeable base material . When the gas pressure is applied in this state, a part where the low melting point element 3A is removed from the fine holes or gaps of the gas permeable base material due to the gas pressure is generated, and this part (low melting point element removing part) of the gas permeable base material A gas bypass passage is formed inside the gas permeable base material by opening fine holes or gaps to open the vent hole 2 of the closed container main body 1 which is closed by the gas permeable base material , and the moisture is discharged from the vent hole 2. It is difficult to permeate and acts so as to permeate gas. Next, when the sealed container body 1 is lowered to a temperature which does not melt the low melting point elements 3A, the low-melting device 3A becomes the gas barrier by obstructing micropores or gaps gas permeable substrate, the gas permeable substrate sealed container The ventilation hole 2 of the main body 1 is closed, and a state is restored in which it is difficult for moisture and gas to permeate through the ventilation hole 2. In this way, the gas can be transmitted through the air-permeable packing depending on the temperature and the internal pressure of the closed container body 1. Depending on the temperature, an opening/closing cycle can be obtained in which the gas is impermeable and the gas is permeable.

(Use of breathable packing)
FIG. 9 shows a closed container body in which the air-permeable packing of the present invention is used, which is formed in a closed container of a closed electrochemical device having an electrode element and an electrolytic solution so that water such as water vapor does not pass through. An example of use in a sealed electrochemical device that facilitates discharge of the gas generated inside to the outside of the sealed container is shown.

In FIG. 9, a sealed electrochemical device is shown in which a pair of electrode terminals 100, 100 are arranged side by side on a lid that becomes the sealed container body 1. This sealed electrochemical device is a capacitor having an electrolytic solution 104, a lithium battery, or the like. A joining member for closing a cylindrical or rectangular parallelepiped box-shaped case 11 having an open end by a lid (closed container body 1) made of a synthetic resin material in the shape of a disc (including an ellipse) or a rectangle. The sealed container of the sealed electrochemical device joined at 12 is constructed. Inside the airtight container, a connection portion 101 of the electrode terminal 100, a lead 102 electrically connected to the connection portion 101, an electrode element portion 103 electrically connected to the lead 102 and an electrolytic solution 104 are hermetically accommodated. Has been done. As described above, in the sealed electrochemical device such as the capacitor or the lithium battery having the electrode element portion 103 and the electrolytic solution 104, the electrolytic solution 104 is sealed so as not to leak out, so that the charging/discharging cycle is not performed. Repeatedly, left at high temperature, decomposed electrolyte 8 due to short circuit, overcharge, reverse charge, etc., gas such as oxygen and carbon dioxide is generated, and the internal pressure rapidly increases due to the accumulation of the gas. There is a possibility that the lid body or the box-shaped case 11 that becomes the closed container body 1 may rise and swell or burst. Therefore, in order to prevent the generated gas from being excessively accumulated in the closed container, a lid body (a ventilation hole 2 is formed in the closed container body 1 and a breathable packing block 10 arranged on the lower surface of the lid body is used to remove vapor etc.). Preventing water from permeating and appropriately discharging the gas generated in the closed container from the ventilation hole 2 to the outside of the lid body which becomes the closed container body 1 to prevent the gas from continuing to accumulate in the closed container. Although not shown, the safety container for opening the sealed electrochemical device may be provided with a safety valve for discharging gas by opening the inside of the sealed container with high pressure in the sealed container.

(Embodiment 2)
10 and 11 show the breathable packing described in the first embodiment, which has a different structure in which the breathable packing is arranged in the closed container main body based on the principle of water impermeable and gas permeable action.

10 and 11, there is a ventilation hole 2 made of a through hole of the closed container body 1 similar to that of the first embodiment, and the ventilation hole 2 has a large space 2A formed inside (lower side in FIG. 10). Has been done. Protective sheets 6 and 7 are fixed to the upper surface and the lower surface of the ventilation hole 2 of the closed container body 1, respectively. The shape of these protective sheets 6 and 7 is rectangular or circular with a thickness of about 0.2 mm, and the material thereof is the same as the material of the gas permeable base material like the protective sheet 5 shown in the first embodiment. ing. Further, a breathable packing 3 is disposed in the space 2A, the breathable packing 3 has an upper surface spaced from the ventilation hole 2 and a lower surface spaced from the protective sheet 7. In this case, the protective sheet 6 protects the low melting point element 3A melted from the ventilation hole 2 so as not to be scattered to the outside (upper part in FIG. 10) of the closed container body 1 , and the protective sheet 7 protects the breathable packing 3 from the closed container. It is useful to protect the internal electrolytic solution (in FIG. 1, the electrolytic solution below the closed container body 1) from being immersed .

In this way, the breathable packing block 10 is obtained. In this case, the breathable packing 3 is made of the same material as that of the first embodiment, and the thickness of the closed container body 1 is large, but the structure thereof can be simplified.

(Embodiment 3)
12 and 13 show different configurations for arranging the breathable packing in the closed container body based on the principle of the water impermeable and gas permeation action of the breathable packing described in the first embodiment.

12 and 13, the closed container body 1 includes an inner layer 1A made of a heat-sealing resin such as polypropylene resin, a metal foil layer 1B made of aluminum or the like, and an outer layer 1C made of polyethylene terephthalate resin as in Patent Document 4. It is made of a moisture-proof multi-layer film. The closed container main body 1 has a vent hole 2 formed by a line-shaped cut 2B penetrating the outer layer 1C and the metal foil layer 1B and a space 2A communicating with the cut 2B and having a larger diameter than the cut 2B in the inner layer 1A. Are formed. The air-permeable packing 3 similar to that of the first or second embodiment in which the air hole 2 is closed via the space 2A is directly fixed to the inner side of the closed container body 1 (the lower surface in FIG. 12), and the air-permeable packing block 10 is formed. can get.

(Different embodiments of use of breathable packing)
FIG. 14 shows a hermetically sealed electrochemical device using the air-permeable packing of the third embodiment, in which a hermetically sealed container of the hermetically sealed electrochemical device having an electrode element and a solid electrolyte is formed as a hermetically sealed container body using the air-permeable packing. Then, an application example to a sealed electrochemical device in which moisture such as water vapor is prevented from permeating and the gas generated in the sealed container is easily discharged to the outside of the sealed container will be shown.

In FIG. 14, the closed container body 1 made of the moisture-proof multilayer film is on the upper side, and the closed container body 11 made of the same moisture-proof multilayer film is on the lower side, and the electrode terminals 100, 100 are provided on the respective end faces. The airtight container body 1 and the airtight container body 11 are heat-welded to each other via the connecting portion 101 of the electrode terminal 100 to form the airtight container. A lead 102 electrically connected to the connecting portion 101 of the electrode terminal 100, an electrode element portion 103 electrically connected to the lead 102, and a solid electrolyte 105 are hermetically accommodated in the sealed container. As described above, in the sealed electrochemical device such as the lithium battery having the electrode element portion 103 and the solid electrolyte 105, the sealed electrochemical device is sealed so as to make it difficult for water and gas to permeate. , The solvent of the solid electrolyte 105 is decomposed by leaving it at high temperature or by short circuit, overcharge, reverse charge, etc., gas is generated, and the gas is accumulated, the internal pressure rises rapidly, and the closed container body 1 and the closed container body 11 may swell or burst. Therefore, in order to prevent the generated gas from being excessively accumulated in the closed container, a ventilation hole 2 is formed in the closed container body 1, and the breathable packing block 10 in which the breathable packing 3 is arranged on the lower surface of the closed container body 1 is used. It is possible to prevent the gas from continuing to accumulate in the closed container by preventing the permeation of moisture such as water vapor and by appropriately discharging the gas generated in the closed container from the ventilation hole 2 to the outside of the closed container. it can.

In Embodiments 1 to 3, the low-melting-point elements 3A dispersed inside the gas permeable base material close the fine holes or gaps of the gas permeable base material by temperature to form a gas barrier, or open the gas bypass passage. or, it is necessary to consider the distribution of the variance of the micropores or gaps and a low melting element 3A of the gas permeable substrate to allow the action or to return to the gas barrier, in its consideration, whether of the protective sheet and containers It is also necessary to set so that the low melting point element 3A does not scatter out of the closed container due to gas pressure in the body.

Although not shown, the breathable packing may be arranged on the upper surface of the closed container body 1 having the ventilation holes 2 made of fine holes, that is, outside the closed container body 1.

The air-permeable packing of the present invention is used for a hermetically sealed container in which gas is generated, the temperature of the hermetically sealed container becomes high, the gas is actively generated, and the pressure in the hermetically sealed container is increased by the generated gas, and particularly the hermetically sealed container It is useful as a sealed electrochemical device such as a capacitor or a lithium battery having an electrolytic solution or a solid electrolyte inside.

1 Airtight container body 2 Vent hole 3 Breathable packing 3A Low melting point element

Claims (2)

The closed container body that constitutes the closed container has a vent hole communicating with the inside and outside, gas is generated inside the closed container, and when the temperature becomes high, the gas is actively generated and the inside of the closed container is generated by the generated gas. A breathable packing block which is used in a hermetically-sealed container whose pressure rises, and which discharges the gas from the ventilation hole to the outside of the hermetically-sealed container in the process of increasing the pressure in the hermetically-sealed container, wherein the air-permeable packing block is , A gas permeable substrate made of a material having fine pores or gaps through which moisture and gas can permeate, and a low melting point element dispersed in the gas permeable base material; It is composed of a protective sheet that protects it from scattering, the breathable packing is disposed inside the closed container body, and the protective sheet is disposed apart from the breathable packing, and the low melting point element is provided. A function of closing the ventilation hole without melting it and a state of melting the low melting point element at a temperature equal to or higher than the melting point and opening the ventilation hole by generating a gas bypass passage through which gas permeates by the pressure of the gas. A breathable packing block characterized in that it has a function to prevent the molten low melting point element from scattering outside . The breathable packing block according to claim 1, wherein the material of the gas permeable substrate is a non-woven fabric.

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