JP2006125559A - Gas bleeding valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas bleeding valve easily assemblable and installable on a container, having excellent closing stability and chemical resistance, and capable of securely preventing the outside air from invading therein over a long period. <P>SOLUTION: This gas bleeding valve is installed, from its inside, in a hole part for releasing gases generated from contents formed in the container. The gas bleeding valve comprises a synthetic resin cup having a recessed part with a bottom face hole and a flange part at the peripheral edge of the recessed part, an elastic and non-permeable valve film laid down to cover the bottom face hole on the inside of the recessed part, and an elastic and permeable synthetic fiber material installed on the valve film on the inside of the recessed part. The synthetic resin cup is adhered and installed onto the inner surface of the container at a flange part so that the bottom face thereof on the inner side of the recessed part faces the hole part of the container. In the installed state, the adhered part of the synthetic resin cup surrounds the hole part of the container, and the synthetic fiber material is pressed by the inner surface of the container to oppress the valve film so as to seal the bottom face hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a degassing valve used for an application in which gas is generated from the contents attached to a sealed container and escaped to the outside of the container, and in particular, from the container of an electric double layer capacitor or a secondary battery. It is related with the gas vent valve suitable for releasing the gas which generate | occur | produced in (1) outside.

  When a gas contained in a sealed container made of a hard material or a soft material generates gas, the pressure in the container may increase unless the gas is released to the outside, and the gas may burst. Conventionally, various venting valves have been used to prevent intrusion of outside air while letting gas generated from the contents of the storage container escape.

  Patent Document 1 describes a gas vent valve having a cross-sectional structure shown in FIG. This degassing valve has a container 601 having a hole 602 for releasing gas generated from the contents, a gas permeable film 603 that blocks the liquid attached to the hole from the inside and transmits the gas, and enters the hole from the outside. The cover 610 is attached and has a discharge hole 612 on the peripheral surface, the valve seat 616 accommodated in the cover, the valve body 615, and the elastic body 618. The valve seat 616 has a ring shape and is fixed at a position concentric with the hole 602 on the outer wall of the container, and the elastic body 618 biases the valve body 615 in the valve closing direction. As a result, the peripheral portion of the valve body 615 contacts the inner peripheral portion of the valve seat 616 and the hole 602 is closed.

  However, in this structure, the valve seat 616 is supported by the outer wall of the container. When the container is a soft material such as a bag, the valve seat 616 is not sufficiently supported by the outer wall of the container. The contact force with the seat 616 becomes weak and the sealing performance is poor. Further, the structure in the cover is complicated, and it is necessary to attach members from both the inside and outside of the container 601, so that the attaching operation is complicated.

  Patent Document 2 describes an electric double layer capacitor in which an exterior is formed of an aluminum laminate film, and an electrolytic solution that is a propylene carbonate solution and an activated carbon electrode are accommodated therein. A container made of aluminum laminate film is provided with a resin gas vent valve. FIG. 7 shows a cross-sectional structure of the gas vent valve. The degassing valve 720 includes a pan-like main body 721 having a bottom hole 722 fused to an aluminum laminate film 715, a valve membrane 723 laid on the bottom surface, and a pressing member 724 provided on the valve membrane.

  The valve membrane 723 is operated by the pressure difference between the inside and outside of the container. That is, when the internal pressure of the container is lower than the external pressure, the valve membrane 723 sticks to the bottom surface and the bottom hole 722 is closed (FIG. 7A), and gas is generated and the internal pressure of the container becomes higher than the external pressure. It rises and discharges the gas to the outside (FIG. 7B).

However, in this structure, both end portions of the valve membrane 723 are not always pressed against the bottom surface, and the bottom surface hole 722 is likely to be insufficiently closed over time. Further, this gas vent valve cannot prevent the electrolyte from flowing out from the bottom hole 722. Furthermore, it is necessary to cut out the container in accordance with the dimensions of the pan-shaped main body at the time of attachment, and the attachment operation is complicated.
JP 2000-335649 A JP 2003-297700 A

  The present invention solves the above-mentioned conventional problems, and its object is that it is easy to assemble and attach to a container, has excellent blocking stability and chemical resistance, and ensures the invasion of outside air for a long time. The object is to provide a vent valve that can be prevented.

The present invention is a gas vent valve attached to the hole from the inside to a container having a hole for releasing gas generated from the contents,
A synthetic resin cup having a recess having a bottom hole and a flange portion around the periphery of the recess,
An elastic and non-breathable valve membrane laid on the bottom surface inside the recess to cover the bottom hole, and an elastic and breathable synthetic fibrous material provided on the valve membrane inside the recess,
Have
The synthetic resin cup is attached to the inner surface of the container at the flange portion so that the bottom surface inside the recess faces the hole of the container,
In the attached state, the adhesive part of the synthetic resin cup surrounds the hole of the container, the synthetic fibrous material is pushed by the inner surface of the container, the valve membrane is pressed, and the bottom hole is sealed. A relief valve is provided, whereby the above object is achieved.
The gas vent valve is a gas that blocks the liquid and permeates the gas, with the film body covering the bottom surface hole and the bonding portion surrounding the bottom surface hole on the bottom surface outside the concave portion of the synthetic resin cup. It is preferable to further have a transmissive film.

  FIG. 1 is a sectional view showing a state in which a gas vent valve according to an embodiment of the present invention is attached to a container. The outer wall 10 of the container is provided with a hole 11 through which gas generated from the contents escapes. The container is not particularly limited as long as it is a hermetically sealed container that requires regular degassing while preventing intrusion of outside air, and may be formed of a metal, a hard resin, a soft resin, or a composite material thereof. . For example, the container may be a plastic film, for example, a bag having a polyolefin film, and preferably an aluminum laminate film having a polyolefin film as an inner layer. This is because the polyolefin film is excellent in chemical resistance, particularly resistance to organic solvents. Among the polyolefins, polypropylene is preferable. This is true for the polyolefins described throughout the specification.

  The gas vent valve 1 includes a synthetic resin cup 2, a valve membrane 3, and a synthetic fiber material 4. The material of the synthetic resin cup 2 may be a resin having sufficient rigidity to maintain the shape during use. In view of ease of molding and attachment, a thermoplastic resin is preferable. Polyolefin resins are particularly preferred because of their excellent chemical resistance. The resin cup 2 has a recess having a bottom hole 5 and a flange portion at the periphery of the recess.

  A valve membrane 3 is laid on the bottom surface inside the recess so as to cover the bottom hole 5. The valve membrane 3 is made of a material having elasticity and non-breathability and showing resistance to an organic solvent. Preferably it is rubber or the like. A synthetic fibrous material 4 is provided on the valve membrane 3. The synthetic fibrous material 4 has elasticity and air permeability, and is formed from a material exhibiting resistance to an organic solvent. From such a viewpoint, a fibrous material mainly composed of polyolefin fibers is preferable. Examples of the fibrous material include fiber deposits, woven fabrics, nonwoven fabrics, and combinations thereof. A nonwoven fabric is preferable, and a nonwoven fabric with embossing formed on the entire surface is more preferable. The thickness of the synthetic fibrous material may be appropriately determined according to the opening pressure required for the valve.

  The synthetic resin cup 2 is bonded to the inner side surface of the container 10 at the flange portion so that the bottom surface inside the recess faces the hole of the container 10. The bonding method is not particularly limited, but when the inner surface of the container and the synthetic resin cup are both made of polyolefin, they may be fused. In the attached state, the adhesive portion of the synthetic resin cup 2 surrounds the hole 11 of the container, and the outside air does not touch the contents. In other words, the synthetic resin cup can be attached simply by positioning and bonding.

  The synthetic fibrous material 4 is pushed by the inner surface of the container 10, the valve membrane 3 is pressed, and the bottom hole 5 is sealed. The synthetic fibrous material 4 can push the entire surface of the valve membrane 3, and the bottom hole 5 is reliably sealed. Synthetic fibrous materials with excellent chemical resistance are less likely to deteriorate in elasticity and have excellent sealing durability. The opening pressure of the valve can be easily controlled by changing the thickness of the synthetic fibrous material. In addition, the synthetic fiber material does not require handling in comparison with an elastic body such as a spring, and the assembly operation is very simple.

  FIG. 2 is a sectional view showing a state in which a gas vent valve according to another embodiment of the present invention is attached to a container. The difference from the embodiment shown in FIG. 1 is that the gas permeable film 6 is provided outside the synthetic resin cup recess. The gas permeable film 6 is preferably provided when the content contains a liquid. This is because the provision of the gas permeable film 6 prevents the liquid from being taken out together with the gas and prevents the liquid from entering the valve structure.

  The gas permeable film 6 has a characteristic of blocking a liquid and transmitting a gas, and is formed of a material exhibiting resistance to an organic solvent. From such a viewpoint, a continuous porous structure film of polyfluoroolefin is preferable.

  The gas permeable film 6 is bonded to the outer surface of the synthetic resin cup so that the film body covers the bottom hole and the bonding portion surrounds the bottom hole. Then, the liquid contained in the contents will not leak to the outside. When the synthetic resin cup material is polyolefin and the gas permeable membrane is a continuous porous structure film of polyfluoroolefin, the bonding method is a step of melting the synthetic resin cup material at the bonded portion, It is preferable to carry out by a method including a step of contacting and a step of quenching and curing the contact portion.

  Polyfluoroolefin is difficult to wet with liquid. Therefore, the adhesive or the molten resin does not adhere to the continuous porous structure film of polyfluoroolefin, and is difficult to adhere by a normal adhesion method or fusion method. According to the bonding method used in the present invention, it is considered that the melted polyolefin penetrates into the microporous structure of the polyfluoroolefin, and the polyolefin is cured in that state, thereby exhibiting an anchor effect and enabling strong bonding.

  The degassing valve of the present invention is excellent in blocking stability and chemical resistance, and can reliably prevent the intrusion of outside air for a long period of time. Therefore, it is preferably used by being attached to a container of a secondary battery or an electric double layer capacitor. Can do. For example, in an organic electric double layer capacitor formed by immersing a carbonaceous electrode in an organic solvent, an organic solvent having strong erosion and leaching properties is used as a solvent for the electrolytic solution, and the chemical resistance, sealing property and liquid blocking property are improved. The superior vent valve of the present invention is particularly useful. Specific examples of such an organic solvent include ethylene carbonate, propylene carbonate, γ-butyrolactone, sulfolane, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and acetonitrile.

  The following examples further illustrate the present invention, but the present invention is not limited thereto.

  FIG. 3 is an exploded perspective view of the gas vent valve of the present embodiment. A polypropylene plate with a thickness of 0.5 mm (Mitsubishi Resin “Hishi plate” thickness: 1 mm) is press-molded to form a circular flat bottom recess with a bottom inner diameter of 6 mm, an edge inner diameter of 7 mm and a depth of 1 mm, and a width of 3 mm at the periphery of the recess. A polypropylene cup 32 having a flange portion was formed. One hole 5 having a diameter of 0.5 mm was formed in the center of the recess.

  A PTFE (polytetrafluoroethylene) continuous porous structure film having a thickness of 0.3 mm (“PORFLON” WP-100-100, manufactured by Sumitomo Electric Industries, Ltd.) was cut into a circle having a diameter of 15 mm. The obtained PTFE film 36 was placed on the outer surface of the polypropylene cup 32, and the temperature was raised to 200 ° C. for 5 seconds and held for 10 seconds using an impulse welder manufactured by Munekata Co., Ltd., and then rapidly cooled to room temperature in 10 seconds. As a result, the peripheral portion of the PTFE film 36 was bonded to the outer surface of the polypropylene cup 32 flange portion.

  A rubber sheet having a thickness of 0.2 mm (“EPDM” manufactured by Kogoku Intec Co., Ltd.) was cut into a circle having a diameter of 6 mm, and the obtained rubber sheet 33 was laid on the bottom surface inside the polypropylene cup 32. Next, a 0.8 mm-thick polypropylene fiber non-woven fabric (manufactured by Kmberly-Clark) having embossments with a diameter of about 0.5 mm formed on the entire surface at intervals of about 2 mm is cut into a circle with a diameter of 6 mm and placed on the rubber sheet 33. This polypropylene fiber nonwoven fabric 34 was stacked to obtain a gas vent valve 31.

  This degassing valve was attached to the container to produce an electric double layer capacitor. FIG. 4 is a perspective view of the electric double layer capacitor of this embodiment. FIG. 5 is an AA ′ cross-sectional view of the electric double layer capacitor shown in FIG. 4.

  First, an aluminum laminate bag (made by Dai Nippon Printing) 40 with a polyolefin film on the inner layer of 14cm in length, 11.0cm in width and 1.5cm in width is prepared, and several holes 41 are opened with needles on the side surface near the seal opening. It was. The gas vent valve 31 was attached to the bag 40 by fusing the flange portion of the polypropylene cup so as to surround the hole 41 from the inside of the bag 40.

  An aluminum electrode 47, a carbonaceous electrode 48, and a separator 49, which have been subjected to seal pretreatment on the lead electrode portion in advance, are formed into appropriate dimensions, and aluminum electrode 47 / carbonaceous electrode 48 / separator 49 / carbonaceous electrode 48 / aluminum electrode 47 are formed. A laminated body was obtained by stacking in this order, and this was sandwiched between jigs and inserted into the bag 40. A propylene carbonate solution of tetraethylammonium tetrafluoroborate was poured into the bag 40 as an electrolyte, and the seal port was heat-sealed and sealed in a predetermined reduced pressure state to obtain an electric double layer capacitor.

  The electric double layer capacitor thus obtained can surely release the gas generated during manufacture or during use, and can prevent intrusion of outside air. Further, the electrolytic solution is completely blocked by the PTFE film, so that the liquid is not taken out together with the gas, and the liquid is prevented from entering the valve. Further, it is made of a material having excellent chemical resistance, and the sealing property is reliably maintained for a long time.

It is sectional drawing which shows the state which attached the gas vent valve which is one embodiment of this invention to the container. It is sectional drawing which shows the state which attached the gas vent valve which is the other embodiment of this invention to the container. It is a disassembled perspective view of the degassing valve of an Example. It is a perspective view of the electric double layer capacitor of an Example. FIG. 5 is an AA ′ cross-sectional view of the electric double layer capacitor shown in FIG. 4. It is sectional drawing which shows the structure of the conventional gas vent valve. It is sectional drawing which shows the structure of the conventional gas vent valve.

Explanation of symbols

1 ... degassing valve,
2 ... Synthetic resin cup,
3 ... Valve,
4 ... Synthetic fiber material,
5 ... bottom hole,
6: Gas permeable film.

Claims (8)

A gas vent valve attached to the hole from the inside to a container having a hole for releasing gas generated from the contents,
A synthetic resin cup having a recess having a bottom hole and a flange portion around the periphery of the recess,
An elastic and non-breathable valve membrane laid on the bottom surface inside the recess to cover the bottom hole, and an elastic and breathable synthetic fibrous material provided on the valve membrane inside the recess,
Have
The synthetic resin cup is attached to the inner surface of the container at the flange portion so that the bottom surface inside the recess faces the hole of the container,
In the attached state, the adhesive part of the synthetic resin cup surrounds the hole of the container, the synthetic fibrous material is pushed by the inner surface of the container, the valve membrane is pressed, and the bottom hole is sealed. A vent valve. The gas permeable film which blocks | interrupts the liquid and permeate | transmits gas which the film body covered so that the bottom face hole was covered on the bottom face of the said synthetic resin cup recessed part, and the adhesion part enclosed the bottom face hole, and permeate | transmits gas is further provided. Degassing valve as described. The gas vent valve according to claim 2, wherein the synthetic resin cup material is polyolefin, and the gas permeable membrane is a continuous porous structure film of polyfluoroolefin. The bonding is performed by a method including a step of melting the synthetic resin cup material in the bonding portion, a step of bringing the gas permeable film into contact with the melting portion, and a step of quenching and curing the contact portion. Degassing valve as described. The gas vent valve according to any one of claims 1 to 4, wherein the synthetic fibrous material is a nonwoven fabric comprising polyolefin fibers. The gas vent valve according to any one of claims 1 to 5, wherein the container is a bag having a polyolefin film. The gas vent valve according to claim 6, wherein the bag is formed of an aluminum laminate film having a polyolefin film as an inner layer. A carbonaceous electrode is provided in an electrolyte solution containing at least one organic solvent selected from the group consisting of ethylene carbonate, propylene carbonate, γ-butyrolactone, sulfolane, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and acetonitrile. The degassing valve according to any one of claims 1 to 7, which has a structure of an electric double layer capacitor formed by immersion.

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