JP6784965B2 - Gas permeation member - Google Patents

Description

The present invention relates to a gas permeable member to facilitate exhausting gas generated in the interior of the sealed container to block moisture such as water vapor to the outside of the closed container.

In order to discharge the gas generated inside the closed container to the outside of the closed container and eliminate problems due to the pressure rise inside the closed container, etc., water such as water vapor is blocked and generated inside the closed container. In a closed container such as an electric double layer capacitor having an electrode element and an electrolyte or a lithium battery, the electrolyte is inside the closed container, for which the gas needs to be appropriately discharged to the outside of the closed container. Since it is housed in a sealed container, the electrolyte is decomposed by repeating the charge / discharge cycle, leaving it at a high temperature, short-circuiting, overcharging, reverse charging, etc., and gas such as oxygen and carbon dioxide inside the closed container. Is generated, and the generated gas accumulates inside the closed container, causing the internal pressure to rise sharply, which may cause the closed container body to swell or explode. There is a demand for a gas permeable member that prevents gas that is discharged to the outside of the closed container and increases the internal pressure from accumulating inside the closed container and blocks moisture such as water vapor generated outside the closed container.

In Patent Document 1, a button-type alkaline battery is taken up as a material for a gas permeable member that discharges the generated gas to the outside of the closed container each time to prevent the gas that increases the internal pressure from accumulating inside the closed container. Therefore, a gas permeable member using a polyolefin resin having excellent gas permeability has been proposed. In Patent Document 1, a straight hole having a diameter of 0.7 mm is formed in a negative electrode can (corresponding to a closed container body) that also serves as a case to form a gas vent hole (corresponding to a through hole), and excellent gas permeability is achieved. A sheet-shaped polyolefin resin having a thickness of 0.2 mm is thermocompression bonded to close the hole. Further, in Patent Document 2, a sealed battery in which the opening of the outer can is closed with a lid is taken up, and a gas permeable membrane for escaping (exhausting) the gas generated in the battery to the outside of the battery is attached to the lid. , A zeolite membrane having the property that hydrogen, carbon dioxide, carbon monoxide, lower hydrocarbons, etc. are permeable, but water (water vapor) is impermeable; alumina, zirconia, silica, mullite, Membrane obtained by sintering fine particles of inorganic oxides such as hydrocarbonite and titania; membrane of organic polymer material such as silicone rubber, silicone resin and silicone oil; membrane of carbonaceous material such as graphite; Pd And Pd-based alloy films have been proposed as examples.

However, in the material of the gas permeable member as proposed in Patent Document 1 and Patent Document 2, the gas permeation amount is determined by the characteristics of the material itself, so that the gas permeation amount is increased in order to increase the gas permeation amount. It is necessary to reduce the thickness of the member and increase the surface area, and in a closed-type electrochemical device of a limited size, the gas generated inside the closed container is sufficiently discharged to the outside of the closed container. It's difficult to do.

Therefore, in order to sufficiently discharge the gas generated inside the closed container to the outside of the closed container, in Patent Document 3, the electrolytic capacitor is taken up and a storage unit for storing the electrolytic solution by a cap that seals the upper surface of the base. Each particle of the filler is electrolyzed by pressure molding a resin composite such as a phenol resin composed of a filler such as alumina having an average particle size of 1 to 40 μm so that the cap serves as a gas permeable member. It is cured in a partially bonded state to form pores with an average pore size of 0.01 to 2 μm by the gaps between the particles, and the cap allows hydrogen gas to permeate and block the permeation of electrolytic solution and water vapor. A gas permeable member has been proposed.

However, in the resin composite that allows only hydrogen gas to permeate as proposed in Patent Document 3, the pores are not the predetermined pore diameter, but the particles of the filler having an average particle size of 1 to 40 μm are partially bonded. Since it is cured and formed by the gaps between the particles, it takes time and effort to stably obtain the pore diameter and the pore ratio, and the gas permeable member that allows only hydrogen gas to permeate blocks the electrolytic solution and water vapor. However, consideration is not given to discharging a gas other than the hydrogen gas generated inside the closed container, that is, a gas such as oxygen or carbon dioxide, to the outside of the closed container.

In the above Patent Documents 1, 2 and 3, the problems of gas permeable members in button-type alkaline batteries, sealed batteries and electrolytic capacitors have been taken up, respectively, but devices used indoors around water or electrical equipment for vehicles have been taken up. In equipment such as products, sensors, portable devices, etc. that are used outdoors and are used in a sealed manner, pressure cannot be adjusted when pressure or temperature changes or gas is generated inside. There is also a demand for a gas permeable member that prevents moisture and water vapor in the air from entering the inside through the ventilation holes, causing rust and mold to deteriorate the circuit and equipment and prevent them from performing their normal functions.

As this gas permeable member, in Patent Document 4, the plasticizer is removed from the film formed by melt-kneading a raw material composition mainly composed of a polyolefin resin, an inorganic powder, and a plasticizer to form an inorganic powder. The skeleton is made of a porous film consisting of a single-layer structure in which a three-dimensional network structure in which a polyolefin resin is bonded as an adhesive functional material is formed and innumerable communication holes having intricate and complicated paths are formed. It has been proposed to use the water vapor permeation prevention porous film in equipment used outdoors such as electrical components for vehicles, sensors, portable equipment, etc., which is used in a sealed manner.

However, in the gas permeation member proposed in Patent Document 4, the polyolefin-based resin is a hydrophilic inorganic powder having a weight average molecular weight of 500,000 or more, and the inorganic powder is a hydrophilic inorganic powder having a specific surface area of 100 m ² / g or more. Is made of a hydrophilic porous film having an average pore diameter of 0.05 to 0.2 μm, containing 20 to 50% by mass and 50 to 80% by mass of inorganic powder, and has entered the pores of this porous film. Although the capillary condensing action in which water vapor causes condensation in the pores is utilized, consideration is not given to stably obtaining pores having an appropriate size in this porous structure .

Japanese Unexamined Patent Publication No. 6-150895 Japanese Unexamined Patent Publication No. 2003-217549 Japanese Unexamined Patent Publication No. 2000-286170 Japanese Unexamined Patent Publication No. 2012-30184

The present invention focuses on increasing the gas permeation amount stably in the gas permeation member formed in the airtight container body exemplifying the hermetically sealed electrochemical device having an electrode element and an electrolyte, and does not make it a porous structure. , A gas permeable member in which a through hole having a fine hole diameter is formed in a base material which is a constituent member of a closed container body is found, and the above problem can be solved.

The gas permeable member of the present invention dissolves or decomposes the thermoplastic synthetic resin component into a substrate made of a thermoplastic synthetic resin material containing an inorganic filler as a constituent member of a closed container body by irradiation with laser light to obtain fine particles. In a gas permeation member that forms a through hole having a large hole diameter and discharges gas inside a closed container to the outside through the through hole , the through hole has a conical inner peripheral wall and the conical inner peripheral wall. Is combined vertically and has a drum shape consisting of holes with a hole diameter of 0.01 to 100 μm at an intermediate position in the irradiation depth direction of the laser light, and the inorganic filler is applied to the inner peripheral wall of the through hole by irradiation with the laser light. It is characterized in that it is left to exhibit a gas selection action utilizing the difference in gas permeability with respect to the through hole to block water such as water vapor.

The gas permeable member exemplifying the sealed electrochemical device of the present invention is a base material made of a thermoplastic synthetic resin material containing an inorganic filler, which is a constituent member of a closed container body, and is subjected to laser light irradiation to the thermoplastic synthetic resin. In a gas permeation member that dissolves or decomposes a component to form a through hole having a fine hole diameter and discharges the gas inside the closed container to the outside through the through hole , the through hole has a conical inner peripheral wall. The conical inner peripheral wall is combined vertically and has a drum shape consisting of a hole having a hole diameter of 0.01 to 100 μm at an intermediate position in the irradiation depth direction of the laser beam, and the inner peripheral wall of the through hole is a laser. The inorganic filler is left by irradiation with light, and a gas selection action utilizing the difference in gas permeability to the through hole is exhibited to block water such as water vapor. Therefore, a thermoplastic synthesis containing no inorganic material filler. Compared with the resin material, even if the base material is a plate-shaped thin-walled material, the strength is high, and a gas permeable member having improved gas permeability and a large amount of gas permeation can be obtained.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 2 showing a gas permeable member formed in a closed container body or tightly bonded to the closed container body in the first embodiment of the present invention. It is a top view which shows the gas permeation member formed in the closed container main body or tightly joined to the closed container main body in Embodiment 1 of this invention. It is a rear view which shows the gas permeation member formed in the closed container main body or tightly joined to the closed container main body in Embodiment 1 of this invention. FIG. 5 is a cross-sectional view taken along the line BB of FIG. 5 showing a gas permeable member formed in the closed container body or tightly joined to the closed container body in the second embodiment of the present invention. It is a top view which shows the gas permeation member formed in the closed container body or tightly joined to the closed container body in Embodiment 2 of this invention. It is sectional drawing which shows a part of the closed container in which the gas permeation member of Embodiment 1 or Embodiment 2 of this invention is tightly joined to the closed container main body. It is sectional drawing which shows a part of the closed container which formed the gas permeation surface layer sheet by tightly joining the gas permeation member of Embodiment 1 or Embodiment 2 of this invention to a closed container main body. FIG. 5 is a cross-sectional view showing a part of a closed container in which a gas permeable member according to the first or second embodiment of the present invention is tightly bonded to a closed container body and a gas permeable surface sheet is formed in a different embodiment. It is sectional drawing which shows the state which the gas permeation member of Embodiment 1 or Embodiment 2 of this invention is tightly joined to the closed container main body of the closed type electrochemical device. It is sectional drawing which shows the state which laser-processes the base material integrally molded with the closed container body in Embodiment 3 of this invention. It is sectional drawing which shows the gas transmission member formed by laser processing the base material of the gas transmission member of FIG. It is sectional drawing which shows the working state which forms the gas permeation surface layer sheet on the base material of the gas permeation member of FIG. It is sectional drawing which shows the main part of the closed type electrochemical device which used the gas permeable member made by the formation work of the gas permeable surface layer sheet of FIG. It is sectional drawing which shows the state which formed the gas permeation surface layer sheet on the base material of the gas permeation member in Embodiment 4 of this invention. FIG. 5 is a cross-sectional view taken along the line CC of FIG. 16 showing a gas permeable member formed in a closed container body according to the fifth embodiment of the present invention. It is a top view which shows the gas permeation member formed in the closed container body in Embodiment 5 of this invention. It is sectional drawing which shows the closed type electrochemical device which formed the gas permeation member in the closed container body in Embodiment 5 of this invention. It is sectional drawing which shows the state which laser-processes the closed container body in Embodiment 6 of this invention. It is sectional drawing which shows the gas transmission member which was made by laser processing the closed container body in Embodiment 6 of this invention. It is sectional drawing which shows the main part of the closed type electrochemical device which formed the gas permeation surface layer sheet on the gas permeation member of FIG. 19 in Embodiment 6 of this invention. It is an optical micrograph which shows the processed surface in the laser-machined through hole of Example 1, and (A) and (B) are photograph taken from the upper surface and the lower surface, respectively. It is an optical micrograph showing the processed surface in the laser-machined through hole of Example 2, and (A) and (B) are photographs taken from the upper surface and the lower surface, respectively.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The gas permeation member formed on the base material which is a constituent member of the closed container main body will be described with reference to FIGS. 1 to 3.

Reference numeral 1 denotes a gas permeation member composed of through holes 3 formed in the base material 2. The base material 2 is a member that is tightly bonded to the closed container main body 4 (see FIGS. 6 to 9) by adhesion, welding, molding, etc., and serves as a constituent member of the closed container main body 4, and the gas permeation member 1 is the base material. It is formed in the closed container main body 4 via 2. The material of the base material 2 is a thermoplastic resin such as polyamide resin, polypropylene resin, polybutylene terephthalate resin, polyphenylene sulfide resin, or a heat-curable resin such as phenol resin, epoxy resin, polyimide resin, and unsaturated polyester resin. Yes, multiple resin materials were mixed, or resin materials were used as the main component, and additives such as elastomers, plastics, and flame retardants, and inorganic materials such as carbon fibers, metals, glass, ceramics, and clay minerals were mixed. It may be used as a material. In addition to these resin materials, there are rubber material materials such as butyl rubber, silicone rubber, and fluororubber, metal materials such as aluminum and stainless steel, and inorganic material materials such as glass, ceramics, and clay minerals. Patent Document 1 It may be a polyolefin resin having excellent gas permeability proposed in 1 or a porous material proposed in Patent Document 3.

As the shape of the base material 2, a flat plate shape and a thickness t of 50 to 200 μm are exemplified, but a thin material smaller than 2 mm and an uneven shape may be used. By using this base material 2, a through hole 3 having a fine hole diameter is formed, so that it can also be used as a breakable explosion-proof valve.

The gas permeation member 1 is formed on the base material 2 as in the second embodiment described later, and the base material 2 may be tightly bonded to the closed container main body 4 in order to form a constituent member of the closed container main body 4. Although it may be integrally molded with the base material 2 as shown in the third embodiment described later, the base material 2 and the closed container main body 4 are not separated in this way, and the following embodiments 5 and 6 can be used. As shown, the closed container main body 21 may have a through hole 32 having a fine hole diameter formed in the closed container main body 4 itself.

The base material 2 is formed with a drum-shaped through hole 3 having one or a plurality of fine hole diameters penetrating from the upper surface 2A to the lower surface 2B, and the through hole 3 has a perfect circle or an oval cross section. It has a cylindrical shape and a conical shape or a drum shape made up of holes with different sizes of the inner peripheral wall surface, and the holes are machined so that the minimum hole diameter R is 0.01 to 100 μm. At the time of processing, the hole diameter of the through hole 3 is set so as to exhibit a gas selection action utilizing the difference in gas permeability to block water vapor and the like. The hole processing is performed by laser processing of a laser light source such as a YAG laser, YVO4 laser, GdVO4 laser, and YLF laser, preferably laser processing that irradiates laser light from a short wavelength pulse laser device L by wavelength conversion, a microdrill, or a microneedle. It may be machined by drilling or chemically etched. Laser processing is preferable as the processing of the through hole 3, and in the first embodiment, as shown in FIG. 1, a gas permeation in which a through hole 3 having a fine hole diameter is formed in the base material 2 by the laser device L. Member 1 is obtained. The through hole 3 formed by the laser device L is focused by a condenser lens (not shown) to obtain a through hole 3 having a minimum hole diameter R of 0.01 to 100 μm, and the base material 2 has a through hole 3. It has an inner peripheral wall surface 3A that is inclined so that the thickness direction, that is, the irradiation depth direction of the laser beam gradually becomes smaller than the hole diameter R1 of the upper surface 2A and the hole diameter R2 of the lower surface 2B, and the minimum hole diameter R is obtained at the intermediate position. A gas permeable member 1 formed in a drum shape by combining conical holes vertically is obtained.

21 and 22 are optical micrographs showing the processed surface of the gas permeable member 1 in the through hole 3 laser-machined so that the through hole 3 having a minimum hole diameter R of 0.01 to 100 μm can be obtained in the base material 2. Is shown.

In FIG. 21, the base material 2 of the gas transmission member 1 is a 200 μm-thick film made of polyphenylene sulfide (PPS) resin, and has a short wavelength in the central portion of the base material 2 due to wavelength conversion of a laser light source of a YVO4 laser. FIG. 1 is obtained by irradiating the upper surface 2A of the base material 2 with a pulse laser device L (laser wavelength 355 nm, pulse width 14 ns, pulse frequency 50 KHz, lens focal length 50 mm, output 0.54 W, number of shots per hole 5000). As shown in (Example 1), a through hole 3 in which the minimum hole diameter R, the hole diameter R1 of the upper surface 2A of the base material 2 and the hole diameter R2 of the lower surface 2B are formed is obtained (Example 1). By imaging the upper surface 2A of the base material 2 as shown in FIG. 2 as the laser-machined surface in the through hole 3 with an optical microscope device, the optical micrograph shown in FIG. 21 (A) is obtained. According to this photograph, the resin is melted or decomposed on the upper surface 2A of the base material 2 by irradiation with a laser beam, and a recess corresponding to the pore diameter R1 is seen on the upper surface 2A, and the minimum pore diameter R is located at the center of the recess. A hole corresponding to is shown. Further, by turning the base material 2 upside down and imaging the lower surface 2B with an optical microscope device, an optical microscope photograph shown in FIG. 21 (B) is obtained, and a recess corresponding to the pore diameter R2 is seen on the lower surface 2B, and the recess is formed. A hole corresponding to the minimum hole diameter R is shown at the center position of the place. It is shown that a drum-shaped through hole 3 having an inclined inner peripheral wall surface 3A is formed by the recesses and holes on the upper surface 2A and the recesses and holes on the lower surface 2B. Further, when observing the inner peripheral wall surface 3A of the drum-shaped through hole 3, it can be seen that the inner peripheral wall surface 3A of any of the recesses and holes on the upper surface 2A and the recesses and holes on the lower surface 2B has an intricate wall shape. Be done.

In FIG. 22, the base material 2 of the gas permeation member 1 is an injection-molded sheet made of polyphenylene sulfide (PPS) resin and having a thickness of 150 μm, which is irradiated on the upper surface 2A of the base material 2 in the same manner as in FIG. By irradiating the pieces, as shown in FIG. 1, a plurality of through holes 3 in which the minimum pore diameter R, the pore diameter R1 of the upper surface 2A of the base material 2 and the pore diameter R2 of the lower surface 2B are formed can be obtained (Example 2). ). By imaging the upper surface 2A of the base material 2 as shown in FIG. 2 as the laser-machined surface in the through hole 3 with an optical microscope device, the optical micrograph shown in FIG. 22 (A) is obtained. According to this photograph, a recess corresponding to the hole diameter R1 is shown on the upper surface 2A of the base material 2, and a hole corresponding to the minimum hole diameter R is shown at the center position of the recess. Further, by turning over the base material 2 and imaging the lower surface 2B of the base material 2 with an optical microscope device, an optical micrograph shown in FIG. 22B is obtained, and a recess corresponding to the pore diameter R2 is obtained on the lower surface 2B of the base material 2. A hole corresponding to the minimum hole diameter R is shown at the center position of the recess. It is shown that a drum-shaped through hole 3 having an inclined inner peripheral wall surface 3A is formed by the upper surface 2A and the lower surface 2B. It is shown that a drum-shaped through hole 3 having an inclined inner peripheral wall surface 3A is formed by the recesses and holes on the upper surface 2A and the recesses and holes on the lower surface 2B. Further, when observing the inner peripheral wall surface 3A of the drum-shaped through hole 3, as in FIG. 21, unevenness is found on any of the inner peripheral wall surface 3A of the recess and the hole on the upper surface 2A and the recess and the hole on the lower surface 2B. You can see the intricate wall shape.

In the optical micrographs taken in FIGS. 21 and 22 above, the base material 2 has through holes 3 having minimum hole diameters R of 5 μm and 1.49 μm formed by laser processing at the base at the center of the recess, respectively. Has been done. Since the inner peripheral wall surface 3A of the drum-shaped through hole 3 has a wall shape in which irregularities are intricate, the minimum hole diameter R is even smaller than the above value depending on the portion of the inner peripheral wall surface 3A. It is presumed.

Further, a water repellent such as silicone-based, fluororesin-based, acrylic-based or amide-based, or a surfactant is sprayed on the inner peripheral wall surface of the through hole 3 of the gas permeation member 1 so as to have hydrophilicity or wettability. By applying a water-repellent surface treatment layer or a hydrophilic or wet surface treatment layer by immersion or plasma treatment , moisture such as water vapor is repelled or condensed on the inner peripheral wall surface of the through hole 3. The gas permeation member 1 is obtained by further reducing the permeation of moisture such as water vapor and improving the moisture blocking action.

(Embodiment 2)
In FIGS. 4 and 5, similarly to the first embodiment, the base material is tightly joined to the closed container body to form a constituent member of the closed container, and the gas permeating member formed on the base material is described below. The points different from the first embodiment will be described.

The material of the base material 2 is made of fibrous, scaly, particulate or a combination of these, glass and ceramics, and a thermoplastic resin containing an inorganic material such as clay mineral as a filler, which increases the amount of gas permeation. In order to form a through hole 31 having a fine pore diameter by drilling the base material 2 as described above, a laser device L preferably a laser light source such as a YAG laser, a YVO4 laser, a GdVO4 laser, and a YLF laser is formed on the base material 2. The thermoplastic resin is melted or decomposed by irradiating laser light from the short wavelength pulse laser device L by wavelength conversion, and the filler of the inorganic material remains at least on the inner peripheral wall surface 31A and is exposed, utilizing the difference in gas permeability. Holes are processed so that the gas selective action is exhibited, and through holes 31 having a minimum pore diameter R of 0.01 to 100 μm are formed and smoothed by the filler of the remaining exposed inorganic material. Compared to the inner peripheral wall surface 31A, the action of blocking moisture such as water vapor is improved, and the gas permeating member 1 capable of permeating gas can be obtained. In this case, the hole shape of the through hole 31 is exemplified by a conical shape, but it may be a drum shape like the through hole 3 of the first embodiment.

Since the gas permeation member 1 in which the filler of the inorganic material is present in the through hole 31 is formed by the hole processing in this manner, the base material 2 made of the thermoplastic synthetic resin material containing the filler of the inorganic material is used. Therefore, the strength is high even if the base material 2 is a plate-shaped thin-walled material as compared with the thermoplastic synthetic resin material that does not contain the filler of the inorganic material, and the gas permeability is improved by the hole processing of the through hole 31. A gas permeation member 1 having a large gas permeation amount can be obtained.

(Embodiment of a closed container having the gas permeable members of the first and second embodiments)
6 and 7 show a part of a state in which the base material on which the gas permeable member is formed is tightly bonded to the closed container body and the closed container body has a gas passage space.

In FIG. 6, the closed container main body 4 is the outer shell of the closed container 41 whose lower surface faces the inner 41B of the closed container 41, and the inner 41B is an electrolyte of a closed electrochemical device such as an electric double layer capacitor or a lithium battery. It is a sealed space that can accommodate the heating elements of electronic circuits of electronic control devices for vehicles. The closed container main body 4 is formed with a gas passage space portion 5 formed of a through hole 3 of the first embodiment or a ventilation hole having a larger hole diameter than the through hole 31 of the second embodiment. The gas permeation member 1 made of a flat base material 2 having through holes 3 and 31 adheres to the outer surface 41A of the airtight container 41 (the upper surface of the airtight container body 4 in FIG. 6) in the gas passage space 5. It communicates with the inside 41B of the closed container 41 and the through hole 3 of the first embodiment or the through hole 31 of the second embodiment by being tightly bonded by welding or molding. In this way, the through holes 3 and 31 are set to have a hole diameter large enough to block water vapor and the like so that a gas selection action utilizing the difference in gas permeability is exhibited, and the water vapor and the like can be removed. It is possible to shut off and discharge the gas (oxygen or carbon dioxide) generated in the inside 41B of the closed container 41 to the outside without accumulating in the closed container 41 . Further, the gas passage space 5 makes it easy to send the gas (oxygen or carbon dioxide) generated in the inside 41B of the closed container 41 into the through holes 3 and 31.

Next, FIG. 7 shows the closed container main body 4 in which the gas permeation surface layer sheet 100 is tightly bonded to the inside of the gas passage space 5 in the closed container main body 4 shown in FIG. The gas permeable surface layer sheet 100 is a non-woven fabric, cloth, porous film or sheet made of a synthetic resin material or a metal material, and is made of a material having better gas permeability than the through holes 3 and 31. The gas permeation surface sheet 100 is fixed to the inner peripheral wall of the gas permeation surface sheet 100 by using an adhesive, and on the upper surface of the gas permeation surface sheet 100, through holes 3 and 31 are formed inside the gas permeation space 5. There is a space 5A without contacting the gas, and the inside 41B of the closed container 41 and the space 5B are formed on the lower surface of the gas permeation surface sheet 100. Although the number of gas-permeable surface sheet 100 is one in FIG. 7, a plurality of gas-permeable surface sheets 100 may be polymerized or separated if there are space spaces 5A and 5B. Moisture such as water vapor is blocked by the through holes 3 and 31 of the gas permeation member 1 which are closely joined to the closed container body 4 in this way, and the gas generated in the inside 41B of the closed container 41 (as in FIG. 6). Oxygen and carbon dioxide) can be discharged, and even if there is a liquid such as water in the inside 41B of the closed container 41 in the gas permeation surface sheet 100, the liquid adheres to the through holes 3 and 31 to permeate the gas. It is possible not to reduce the sex.

FIG. 8 shows a closed container main body 4 using a plurality of gas permeable surface sheets similar to those in FIG. 7. Inside the gas passage space 51, the inner peripheral wall is formed in a two-step step shape with a smaller hole diameter closer to the through holes 3 and 31, and two gas permeation surface sheets 100 are formed in the space 51C. The rings 100A are fixed so as to be separated from each other in the vertical direction. In this case, the number of gas permeable surface sheet 100 may be arbitrarily selected to be 1 or 3 or more depending on the size of the gas passage space 51, and the gas permeable surface sheet 100 is directly fixed without using the ring 100A. It may be joined with an adhesive or integrally molded. Above the gas permeable surface sheet 100 of a gas permeable surface sheet 100 spaced vertically in space space 51C has a spatial space 51A so as not to contact with the through-holes 3 and 31, the lower gas permeable surface layer sheet 100 sealed container It is formed so as to have a space 51B from the lower surface of the main body 4. In this case, when a porous film or sheet is used for the gas permeable surface layer sheet 100, the upper and lower gas permeable surface layer sheets 100 may be used so that the hole pitches are shifted vertically. By forming the gas permeation surface layer sheet 100 in the gas passage space 51 in this way, it is difficult for liquids such as water in the inside 41B of the closed container 41 to adhere to the through holes 3, 31. It is possible to prevent a decrease in the gas permeability of 31.

(Embodiment in which the gas permeable members of Embodiments 1 and 2 are used in a sealed electrochemical device)
FIG. 9 is for a closed electrochemical device in which the closed container 41 made of the closed container main body 4 in which the base material 2 on which the gas permeation member 1 shown in FIG. 6 is closely bonded is used as the closed electrochemical device 42. The gas permeation member is shown. Also in FIG. 9, the gas permeation surface layer sheet 100 shown in FIGS. 7 and 8 may be formed in the gas passage spaces 5 and 51.

In FIG. 9, examples of the closed-type electrochemical device 42 include an electric double-layer capacitor and a lithium battery, and the closed container main body 4 has a disk shape (including an ellipse) in which a pair of electrode terminals 9 are arranged side by side. A vent hole having a larger hole diameter than the through hole 3 of the first embodiment or the through hole 31 of the second embodiment is formed of a rectangular plate material, and the vent hole is a plate-shaped thin-walled material having the through holes 3 and 31. By adhering the gas permeable member 1 made of the base material 2 of the above to the closed container main body 4 by adhesion, welding, molding, etc., the inside of the closed electrochemical device 42 (the closed container main body 4 and the box type case 6) It is a gas passage space portion 5, 51 that communicates with the closed interior) and the through holes 3, 31. Although a metal material is exemplified as the material of the closed container main body 4, other materials such as synthetic resin materials may be used. Reference numeral 6 denotes a cylindrical or rectangular parallelepiped box-shaped case that hermetically houses the electrode element 8 and the electrolyte solution 7 of the electrolyte. The material thereof is the same metal material as that of the airtight container body 4, but other materials may be used. Good. The leads 10, 10 and the electrode element 8 and the electrolytic solution 7 that are electrically connected to the pair of electrode terminals 9 by closely joining the box-shaped case 6 to the closed container body 4 and closing the lid are hermetically accommodated. .. As described above, in the closed type electrochemical device 42 such as an electric double layer capacitor or a lithium battery having the electrode element 8 and the electrolytic solution 7, the inside thereof is sealed by the closed container body 4 and the box type case 6. Therefore, the electrolytic solution 7 is decomposed by repeating the charge / discharge cycle, leaving at a high temperature, short-circuiting, overcharging, reverse charging, etc., and gas such as oxygen and carbon dioxide is generated, and the gas is accumulated. As a result, the internal pressure rises sharply, and the closed container body 4 and the box-shaped case 6 may swell or burst, but the generated gas is inside the closed-type electrochemical device 42 (sealed container body 4). And the gas permeation member 1 having through holes 3 and 31 formed by perforating the base material 2 which is a constituent member of the closed container main body 4 so as not to accumulate too much in the inside sealed with the box-shaped case 6. As a result, the gas can be appropriately discharged from the gas passage spaces 5 and 51 to the outside of the closed type electrochemical device 42 through the through holes 3 and 31, so that the gas can be prevented from continuing to accumulate and the through holes 3 can be prevented from continuing to accumulate. , 31 are formed by hole processing performed by setting the minimum pore diameter to block moisture such as water vapor, so that moisture such as water vapor does not permeate through the gas passage spaces 5 and 51 through the through holes 3 and 31. To block water.

Also in this case, although not shown, if the gas permeation surface layer sheets 100 shown in FIGS. 7 and 8 are formed in the gas passage spaces 5 and 51, the through holes of the gas permeation member 1 closely joined to the closed container body 4 are formed. 3 and 31 block moisture such as water vapor, and the gas (oxygen and carbon dioxide) generated inside the closed type electrochemical device 42 is closed type from the gas passage spaces 5 and 51 through the through holes 3 and 31. When discharged to the outside of the electrochemical device 42, the moisture such as water vapor is blocked from permeating through the through holes 3 and 31 from the gas passage spaces 5 and 51 to block the moisture, and the sealed electrochemical device 42. It is possible to prevent the liquid contained in the electrolytic solution 7 from adhering to the through holes 3 and 31 and prevent the gas permeability of the through holes 3 and 31 from being lowered.

(Embodiment 3)
10 to 13 show a gas permeable member obtained by integrally molding a base material of a gas permeable member made of a synthetic resin material with a closed container body, and will be described below.

In FIGS. 10 and 11, the base material 2 made of a tubular synthetic resin material is integrally molded with the closed container main body 4 made of a metal material to form a tubular shape having a thickness larger than that of the closed container main body 4. The gas permeation member 11 is shown. Examples of the material of the base material 2 include thermoplastic resins such as polyamide resin, polypropylene resin, polybutylene terephthalate resin, and polyphenylene sulfide resin, and the material of the closed container body 4 includes aluminum (containing alloy) and copper (containing alloy). ) Or a metal plate with holes made of stainless steel or the like, and the tubular base material 2 is arranged in the holes of the metal plate. In FIG. 10, the base material 2 has a crosspiece 20 such that a recess 20A is formed above and a gas passage space 52 is formed below, and the crosspiece 20 is insert-molded into the closed container body 4 or the like. It is made by being integrally molded with. By irradiating the crosspiece 20 with laser light from the laser device L from above, a conical through hole 32 in which the upper hole diameter R is larger than the lower hole diameter R1 is obtained as shown in FIG. A gas permeation member 11 communicating with the recess 20A and the gas passage space 52 is formed on the base material 2 above and below the 32, respectively.

FIG. 12 shows a working state in which the gas permeation surface layer sheets 101 and 100 are formed on the base material 2 thus formed in the closed container main body 4 and having the gas passage space 52 and the gas permeation member 11. When the gas permeable surface layer sheets 101 and 100 are pressed against the base material 2 from above and below, respectively, the recess 20A above the base material 2 is adhered so as to be covered with the gas permeable surface layer sheet 101, as shown in FIG. The gas permeation surface sheet 100 is fixed to the inner peripheral wall of the gas passage space 52 below the base material 2 with an adhesive. Similar to FIG. 7, the gas permeation surface layer sheet 100 fixed to the gas passage space 52 has a space 52B formed on the upper surface thereof so as to be separated from the through hole 32 in the gas passage space 52. The materials of the gas permeable surface sheets 100 and 101 are porous made of a polyamide-based resin non-woven fabric, a polyurethane resin-based sponge, a fiber, a polypropylene resin-based synthetic resin material, aluminum (including an alloy), and a metal material such as stainless steel. Examples include films, sheets, and non-woven fabrics. In FIG. 13, the gas permeable member 11 having the gas permeable surface layer sheets 100 and 101 shows the upper part of the closed type electrochemical device 42 in which a pair of electrode terminals 9 are arranged side by side on the closed container main body 4, and the closed type electrochemical is shown. Since the device 42 is sealed by the closed container main body 4 and the box-shaped case 6 and contains the electrolytic solution 7 of the electrolyte as in FIG. 9, the charge / discharge cycle is repeated, the device 42 is left at a high temperature, and a short circuit / excessive is performed. The electrolytic solution 7 is decomposed by charging / reverse charging, and gas such as oxygen and carbon dioxide is generated. The accumulation of the gas causes the internal pressure to rise sharply, and the closed container body 4 and the box-shaped case. 6 may swell or explode, but the generated gas should not accumulate too much inside the sealed electrochemical device 42 (the inside sealed by the closed container body 4 and the box case 6). A gas permeation member 11 having a through hole 32 formed by perforating a base material 2 which is a constituent member of the closed container main body 4 allows gas to be appropriately discharged from a gas passage space 52 through the through hole 32. Since the gas can be discharged to the outside of the chemical device 42, the gas can be prevented from continuing to accumulate, and the gas passage space 52 promotes the gas discharge action. Further, also in the third embodiment, since the through hole 32 is formed by hole processing performed by setting the minimum hole diameter to block water vapor and the like, moisture such as water vapor is allowed to pass through the gas passage space 52 through the through hole 32. It is prevented from being transmitted through. Further, by forming the gas permeable surface layer sheet 100 having better gas permeability than the through hole 32 inside the gas passage space 52, it is difficult for the liquid of the electrolytic solution 7 to adhere to the through hole 32 and the gas permeability is prevented. I try not to lower it. Further, since the recess 20A formed above the base material 2 is covered with the gas surface layer sheet 101, the gas permeability due to the dust generated outside the closed container main body 4 adhering to the through hole 32. It is possible to prevent the decrease.

(Embodiment 4)
FIG. 14 shows a different embodiment in which the gas permeation surface sheet 100 shown in the third embodiment is formed inside the gas passage space portion.

In FIG. 14, the gas permeation member 11 has a tubular shape by integrally molding a base material 2 made of a tubular synthetic resin material into a closed container body 4 made of a metal material as in the third embodiment. However, the shape of the gas passage space portion 53 communicating with the through hole 32 is different from that of the third embodiment, and the inner peripheral wall of the gas passage space portion 53 has a two-step step shape in which the hole diameter is smaller near the through hole 32. It is formed. Two gas-permeable surface sheets 100 separated vertically are fixed to the gas passage space 53 by rings 100A, respectively. In the two gas permeable surface sheet 100 separated above and below, the upper gas permeable surface sheet 100 in the gas passage space 53 is separated from the through hole 32 with a space, and the lower gas. The transparent surface layer sheet 100 is separated from the lower surface of the closed container main body 4 with a space. The material of the gas permeable surface layer sheet 100 is a porous film made of a synthetic resin material or a metal material similar to that of the gas permeable surface layer sheet 100 of the third embodiment, or a sheet or a non-woven fabric. In this case, the number of gas-permeable surface layer sheets 100 can be arbitrarily selected to be one or three or more depending on the size of the gas passage space 53. In particular, when a porous film or a sheet is used for the gas permeable surface layer sheet 100, the upper and lower gas permeable surface layer sheets 100 may be used so that the hole pitches are shifted vertically. Further, the recess 20A is provided above the base material 2 as in the third embodiment, and the recess 20A is covered with the gas surface layer sheet 101. By using the base material 2 formed in the closed container main body 4 thus formed in the closed electrochemical device 42 as in the third embodiment shown in FIG. 13, it is housed inside the closed electrochemical device 42. It is possible to prevent the liquid of the electrolytic solution from adhering to the through hole 32 and prevent the gas permeability of the through hole 32 from being lowered. Further, the gas permeable surface layer sheet 100 may be fixed by directly joining with an adhesive or integrally molding without using the ring 100A. By providing the gas permeation surface layer sheet 100 inside the gas passage space 53 in this way, it is possible to prevent the liquid from adhering to the through hole 32 and prevent the gas permeation of the through hole 32 from being lowered.

(Embodiment 5)
15 and 16 show a gas permeable member in a state where the base material is the main body of the closed container, which is the outer shell of the closed container.

The closed container main body 21 is made of a plate material having a thickness t of 1 to 2 mm made of a synthetic resin material or a metal material, and a gas permeation member 12 having a conical through hole 32 is formed by hole processing. The conical through hole 32 has a shape in which the hole diameter R1 of the upper surface 21A of the closed container main body 21 is larger than the minimum hole diameter R of the lower surface 21B. For hole processing to obtain such a conical through hole 32, laser light is emitted from a laser device L of a laser light source such as a YAG laser, a YVO4 laser, a GdVO4 laser, and a YLF laser, preferably a short wavelength pulse laser device L by wavelength conversion. Although the laser processing for irradiating is illustrated, instead of the laser processing, mechanical processing by drilling such as a microdrill or a microneedle or chemical etching processing may be used.

(Embodiment in which the gas permeable member of Embodiment 5 is used for a closed-type electrochemical device)
In FIG. 17, the upper surface 21A of the closed container body 21 is the outer surface of the closed electrochemical device 42, and the closed electrochemical device 21 has a through hole 32 and a pair of electrode terminals 9 are arranged side by side. 42 is shown, and the sealed electrochemical device 42 is joined with an electric double-layer capacitor or a lithium battery having an electrolytic solution 7 of an electrolyte so as to close a cylindrical or rectangular box-shaped case 6 having an open end. It becomes the closed type electrochemical device 42. The leads 10 and 10, the electrode element portion 8 and the electrolytic solution 7 are airtight inside the sealed electrochemical device 42 (the inside sealed by the closed container body 21 and the box-shaped case 6) as in FIG. It is provided in a state, that is, sealed. As described above, in the sealed electrochemical device 42 such as the electric double layer capacitor and the lithium battery having the electrode element 8 and the electrolytic solution 7, since the inside thereof is sealed, the charge / discharge cycle is repeated and the temperature is high. The electrolytic solution 7 is decomposed by leaving it in the room, short-circuiting, overcharging, reverse charging, etc., and gas such as oxygen and carbon dioxide is generated, and the accumulated gas causes the internal pressure to rise sharply. Since the closed container body 21 and the box-shaped case 6 in the closed electrochemical device 42 may swell or explode, a through hole is provided so that the generated gas does not accumulate too much inside the closed electrochemical device 42. The gas can be appropriately discharged to the outside of the closed-type electrochemical device 42 by the 32, and the water is blocked by preventing the permeation of water such as water vapor.

(Embodiment 6)
18 to 20 show gas permeable members in a state where the base material is the outer shell of the closed container, which is the main body of the closed container, as in the fifth embodiment, and the shape of the base material is different from that of the fifth embodiment.

In FIG. 18, the closed container main body 21 is a metal plate made of aluminum (containing alloy), copper (containing alloy), stainless steel, or the like, and the metal plate is unevenly processed to form a part of the upper surface 21A of the closed container main body 21. A convex curved surface 22 protruding upward is formed, and the lower surface 21B is the inside of the sealed electrochemical device 42 (see FIG. 20). In order to form a through hole having a fine hole diameter so as to increase the amount of gas permeated, a laser device L is applied to the convex curved surface 22 of the upper surface 21A of the closed container main body 21 as shown in FIG. A conical through hole 32 is formed having a hole diameter larger than the minimum hole diameter of the lower surface 21B. As described above, in the closed container main body 21 formed with the through hole 32, a gas permeation member 13 having a gas passage space 54 communicating with the through hole 32 having a hole diameter larger than that of the through hole 32 is obtained, and a gas discharging action is performed. It is promoting .

In FIG. 20, as shown in FIG. 17, the base material is a closed container main body 21 in which a pair of electrode terminals 9 are arranged side by side, and the upper surface 21A thereof is the outer surface of the sealed electrochemical device 42 and is sealed with the box-shaped case 6. The sealed electrochemical device 42 containing the electrolytic solution 7 of the electrolyte is shown. Unlike FIG. 17, the sealed electrochemical device 42 has a gas passage space 54 and a gas permeation surface sheet 100.

In FIG. 20, since the closed-type electrochemical device 42 is sealed by the closed container main body 21 and the box-shaped case 6 and contains the electrolytic solution 7 of the electrolyte, the charging / discharging cycle is repeated or the gas is left at a high temperature. , The electrolytic solution 7 is decomposed by short circuit, overcharge, reverse charge, etc., and gas such as oxygen and carbon dioxide is generated, and the internal pressure rises sharply due to the accumulation of the gas, and the closed container body 21 The box-shaped case 6 may swell or explode, but the generated gas accumulates inside the sealed electrochemical device 42 (the inside sealed by the closed container body 21 and the box-shaped case 6). Through the through hole 32 formed by drilling the convex curved surface 22 of the closed container body 21 so as not to be too much, gas is appropriately sent from the gas passage space 54 to the outside of the closed electrochemical device 42 through the through hole 32. Since the gas can be discharged, the gas can be prevented from being continuously accumulated, and the gas passage space 54 promotes the gas discharge action. Further, in the gas passage space portion 54, the gas permeation surface layer sheet 100 having better gas permeability than the through hole 32 is bent into a convex curved shape and fixed to the inner peripheral wall of the convex curved surface 22 of the gas passage space portion 54. On the upper surface of the gas permeable surface sheet 100, a space 54A is formed between the gas permeable surface sheet 100 and the through hole 32, and on the lower surface of the gas permeable surface sheet 100, a gas permeable member 13 in which the space 54B is formed is obtained. The gas permeation surface sheet 100 makes it difficult for the electrolytic solution 7 of the sealed electrochemical device 42 to adhere to the through hole 32, and has an effect of preventing a decrease in gas permeability due to the adhesion of the liquid.

Based on FIGS. 1 and 2, a through hole 3 having a minimum hole diameter R of 0.01 to 100 μm is formed by hole processing so that a gas selection action utilizing the difference in gas permeability is exhibited and the amount of gas permeation is increased. Hereinafter, an example in which it has been found that the gas permeable member 1 formed on the base material 2 maintains the blocking of moisture such as water vapor and improves the gas permeability will be described below.

As the thin-walled material of the base material 2, a disk-shaped film having a diameter of 35 mm made of polyphenylene sulfide (PPS) resin having a thickness of 200 μm was prepared. From the short wavelength pulse laser device L (laser wavelength 355 nm, pulse width 14 ns, pulse frequency 50 KHz, lens focal distance 50 mm, output 0.54 W, number of shots per hole 5000) by wavelength conversion of YVO4 laser light source on this base material 2. One piece (Example 1-) which is formed by irradiating laser light with a recess on the upper surface and the lower surface and a drum-shaped through hole 3 composed of a hole having a hole diameter of 5 μm at an intermediate position in the thickness direction, that is, the irradiation depth direction of the laser light. 1), 5 through holes 3 separated by 500 μm (Example 1-2) and 10 through holes 3 separated by 500 μm (Example 1-1) were formed to form a gas permeation experimental device GTR manufactured by GTR Tech Co., Ltd. Using −TUBE16-NIT, the water permeability is determined based on JIS standard K7129 at a temperature of 40 ° C and humidity of 90%, and the gas permeability of oxygen and carbon dioxide is determined by JIS standard K7126-2 (etc.). Based on the pressure method), it was determined at a temperature of 80 ° C., and the permeation amounts of water, oxygen, and carbon dioxide per unit time were calculated to obtain the 24-hour permeation amount shown in Table 1.

(Comparative Example 1)
A film made of polyphenylene sulfide (PPS) resin having the same size as that of Example 1 was prepared as a thin-walled material of the base material 2, and water, oxygen, and carbon dioxide were respectively prepared as in Example 1 without irradiating the laser beam. The permeation amount per unit time was calculated to obtain the permeation amount for 24 hours shown in Table 1.

As the thin-walled material of the base material 2, an injection-molded sheet made by injection-molding a polyphenylene sulfide (PPS) resin into a disk shape having a thickness of 150 μm and a diameter of 5.6 mm was prepared. From the short wavelength pulse laser device L (laser wavelength 355 nm, pulse width 14 ns, pulse frequency 50 KHz, lens focal distance 50 mm, output 0.54 W, number of shots per hole 5000) by wavelength conversion with a YVO4 laser light source on this base material 2. Irradiating the laser beam, the upper surface and the lower surface of the base material 2 became a drum-shaped through hole 3 composed of a recess and a hole having a hole diameter of 1.49 μm at an intermediate position in the thickness direction, that is, the irradiation depth direction of the laser light. (Example 2-1), 5 through holes 3 (Example 2-2) separated by 500 μm were formed, and a gas permeation experimental device GTR-TUBE16-NIT manufactured by GTR Tech Co., Ltd. was used. As in Example 1, the water permeability is determined at a temperature of 40 ° C. and a humidity of 90% based on JIS standard K7129, and the gas permeability of oxygen and carbon dioxide is determined by JIS standard K7126-2 (isopressure method). ), The permeation amount of water, oxygen and carbon dioxide per unit time was calculated at a temperature of 80 ° C. to obtain the permeation amount for 24 hours shown in Table 2.

(Comparative Example 2)
An injection-molded sheet made of polyphenylene sulfide (PPS) resin having the same size as in Example 2 was prepared as a thin-walled material for the base material 2, and water, oxygen, and carbon dioxide were prepared in the same manner as in Example 2 without irradiating the laser beam. The permeation amount per unit time was calculated to obtain the 24-hour permeation amount shown in Table 2.

Based on the above measurements, the presence of through-holes as in Examples 1 and 2 has a larger gas permeation amount and a higher water permeation amount than those without through-holes as in Comparative Examples 1 and 2. The result was that the water blockage was maintained to an acceptable level. In addition, the amount of gas permeated when the number of through holes was increased was smaller for carbon dioxide than for oxygen.

The gas permeation member 1 formed by forming the through holes 3, 31, 32 having a fine pore diameter in this way has the through holes 3, 31, 32 so as to exhibit a gas selection action utilizing the difference in gas permeability. moisture degree preferably the size pore size causes the block moisture such as water vapor is if you get a through hole 3, 31, 32 and hole processing is set to 0.01 to 100 [mu] m, the amount of transmitted moisture acceptable It was proved that the gas permeability was improved as compared with the materials whose gas permeation amount was determined by the characteristics of the materials themselves such as Comparative Examples 1 and 2.

The gas permeable member of the present invention is a sealed electrochemical device such as an electric double layer capacitor or a lithium battery as described above, which needs to block water and discharge a gas such as oxygen or carbon dioxide generated inside a closed container. It is useful for making equipment that is used outdoors and used in a sealed manner, such as electrical components for vehicles, sensors, and portable devices, to have breathability.

1, 11 Gas permeation member 2 Base material 3, 31, 32 Through hole 21, 4 Sealed container body 41 Sealed container 42 Sealed electrochemical device 5, 51, 52, 53.54 Gas passage space 100, 101 Gas permeation surface layer Sheet

Claims (1)

A through hole having a fine pore size is formed by dissolving or decomposing the thermoplastic synthetic resin component by irradiating a laser beam on a base material made of a thermoplastic synthetic resin material which is a component of a closed container body and contains an inorganic filler. In the gas permeation member that discharges the gas inside the closed container to the outside through the through hole , the through hole has a conical inner peripheral wall, and the conical inner peripheral wall is vertically combined to emit laser light. It has a drum shape consisting of holes having a hole diameter of 0.01 to 100 μm at an intermediate position in the irradiation depth direction of the above, and the inorganic filler is left on the inner peripheral wall of the through hole by irradiation with laser light to the through hole. A gas permeable member characterized by exhibiting a gas selection action utilizing the difference in gas permeability to block water such as water vapor.

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