WO2015129866A1

WO2015129866A1 - Sealing member

Info

Publication number: WO2015129866A1
Application number: PCT/JP2015/055888
Authority: WO
Inventors: 青山　高久; 英樹河野; 継紅劉
Original assignee: ダイキン工業株式会社
Priority date: 2014-02-28
Filing date: 2015-02-27
Publication date: 2015-09-03
Also published as: CN106068413A; KR101856892B1; KR20160119202A; JP2015178899A; JP6011657B2; CN106068413B

Abstract

　Provided is a sealing member capable of achieving a satisfactory sealing effect even when used over a long period of time. An annular sealing member, wherein the sealing member is used while being pressed from both one side and the other side in a pass-through direction in an inner passing-through portion, and the sealing member has a portion in which, when the sealing member is pressed, the compression ratio in the direction of pressing is greater on the outer side than on the inner side.

Description

Sealing member

The present invention relates to a sealing member.

Conventionally, there is a sealing member for closing a gap between members connected to each other and suppressing leakage of fluid from the inside and entry of foreign matter from the outside.

For example, a gasket used for sealing the periphery of an electrode of a lithium ion battery, such as a gasket described in Patent Document 1 (Japanese Patent Laid-Open No. 2013-157155), has been proposed. This gasket is made of resin and is configured to have a portion extending around a hole penetrating vertically.

However, the above-described gasket disclosed in Patent Document 1 is configured only to have a uniform thickness as a whole, and is more effective for leakage of fluid and entry of foreign matter from the outside. The shape of a sealing member such as a gasket that can be suppressed is not described. In particular, no consideration has been given to a shape capable of maintaining a good sealing state even when a long time has passed in a state where the sealing member is used and pressed.

This invention is made | formed in view of the point mentioned above, The subject of this invention is providing the sealing member which can acquire a favorable sealing effect even when it is a case where it uses for a long time. .

The sealing member according to the first aspect is an annular sealing member, and is used in a state where it is pressed from one side and the other side in the penetrating direction in the inner penetrating portion. In the pressed state, the sealing member has a portion where the compression ratio in the pressed direction is larger on the outside than on the inside.

The sealing member according to the second aspect is the sealing member according to the first aspect, and is configured such that the thickness in the pressed direction increases from the inside toward the outside.

The sealing member according to the third aspect is the sealing member according to the first aspect or the second aspect, and has a tensile elastic modulus of 0.8 GPa or less.

The sealing member according to the fourth aspect is a sealing member according to any one of the first to third aspects, and includes a perfluoropolymer.

The sealing member according to the fifth aspect is the sealing member according to the fourth aspect, and the PFA content is 50 wt% or more and 100 wt% or less.

The sealing member according to the sixth aspect is a sealing member according to any one of the first to fifth aspects, and is used for a battery gasket.

The sealing member according to the present invention has a portion having a larger compression ratio on the outer side than on the inner side, so that the sealing effect can be improved when used by pressing from the penetration direction. .

It is a top view of sealing member 10 as a candidate for simulation. It is a top view of the sealing member 110 as an example. It is a top view of the sealing member 210 as an example. It is side view sectional drawing of the sealing member 10 as the object of simulation. It is side surface sectional drawing of the sealing member 10X as the object of simulation. FIG. 6 is a side sectional view of a sealing member 310 as an example. FIG. 4 is a side sectional view of a sealing member 410 as an example. FIG. 5 is a side sectional view of a sealing member 510 as an example. It is sectional drawing of the side view of the sealing member 610 as an example. FIG. 10 is a side sectional view of a sealing member 710 as an example. It is sectional drawing of the side view of the sealing member 10Y as a comparison object of simulation. It is a side view sectional view of sealing member 10Z as a comparison object of simulation. It is a diagram which shows the relationship between a nominal stress and a nominal strain. It is a diagram which shows the relationship between a true stress and a true strain. It is a graph which shows the simulation result regarding the magnitude | size of the repulsion force after 200,000 hours of the sealing member at the time of changing inclination-angle (alpha) and (beta). It is a graph which shows the simulation result which shows the change of the repulsive force according to the elapsed time from the use start of a sealing member. It is a graph which shows the simulation result of a time-dependent change in the case of the material in which repulsive force becomes double. It is a graph which shows the simulation result regarding the relationship of the repulsive force after 200,000 hours with respect to a friction coefficient. It is a figure which shows the initial state of the repulsive force according to the position of radial direction. It is a figure which shows the state which 10,000 hours passed of the repulsive force according to the position of radial direction. It is a figure which shows the state which 100,000 hours passed of the repulsive force according to the position of radial direction. It is a figure which shows the state which 200,000 hours passed of the repulsive force according to the position of radial direction. It is a side view which shows the state before the press of the gasket used around the electrode of a battery. It is a side view which shows the use condition in which the gasket used around the electrode of a battery was pressed.

Hereinafter, the sealing member according to the embodiment of the present invention will be described.

(1) Use of sealing member The use of the sealing member is not particularly limited, and examples thereof include a gasket and packing.

Especially, the sealing member used for a battery gasket is preferable.

An example of such a battery is a lithium ion battery. As an electrolytic solution of this lithium ion battery, one that is unlikely to occur until deterioration reaches 60 ° C. or higher is desirable.

When used as a gasket for a battery, the sealing member is preferably used such that a battery electrode (for example, a positive electrode or a negative electrode) is located in a portion penetrating inside the sealing member.

(2) Shape of the sealing member The shape of the sealing member is an annular shape, and is used in a state where it is pressed from one side and the other side in the penetrating direction at the inner penetrating portion. The compression ratio in the pressed direction is not particularly limited as long as it has a portion where the outer side is larger than the inner side.

Although not particularly limited, for example, in the case of having inclined surfaces up and down, the inclined surface may be inclined at 10 degrees or more and 80 degrees or less with respect to a plane whose normal is the penetrating direction, You may incline at 20 degree or more and 70 degrees or less.

In the following, regarding the shape of the annular sealing member, the upper surface, the lower surface, and the like will be described on the assumption that the inner penetrating portion penetrates in the vertical direction.

Here, the term “annular” includes a cylindrical shape in which the inner cylindrical portion 11 is cut out and the outer periphery 12 is circular, as in the sealing member 10 shown in the plan view of FIG. As shown in the plan view of the sealing member 110, a square tube in which the inner rectangular portion 111 is hollowed out and the outer periphery 112 is square is included, and like the sealing member 210 shown in the plan view of FIG. A shape in which the center with respect to the hollowed portion 211 and the center with respect to the outer periphery 212 are eccentric is also included. In addition, the shape of the hollowed portion on the inner side in plan view of the sealing member is not particularly limited, and may be a hollowed shape of a cylindrical shape, or a polygonal column such as a quadrangular column or a pentagonal column. It may be a hollow shape. Similarly, the shape of the outer edge of the sealing member in plan view is not particularly limited, and may be an arc shape or a polygonal shape.

The annular sealing member may be configured such that the pressed portion to be pressed in the usage state increases in thickness in the direction in which it is pressed from the inside toward the outside in the non-pressed state. Specifically, like the sealing member 10 shown in FIG. 4 which is a cross-sectional view including a line extending in the penetrating direction including the center of the penetrating portion on the inner side of the sealing member, the upper surface 13 is positioned upward toward the outer side. The bottom surface 14 may be shaped so as to be positioned downward as it goes outward, or like the sealing member 10X shown in FIG. 5, the upper surface 13x is positioned upward as it goes outward, and the lower surface 14x extends to the same height position. The shape may be different. Here, the upper side and the lower side in the direction perpendicular to the penetrating direction from the viewpoint of easily obtaining a sealing effect by improving the balance of force when pressed from one side and the other side in the penetrating direction of the sealing member It is more preferable that the shape of

Further, the upper and lower portions of the sealing member do not need to form a plane, and are, for example, cross-sectional views including a line extending in the penetrating direction including the center of the penetrating portion inside the sealing member. 6, the upper portion 313 may bulge upward and the lower portion 314 may bulge downward, or as the sealing member 410 illustrated in FIG. 7. Alternatively, the upper portion 413 may be recessed downward and the lower portion 414 may be recessed upward. Further, like the sealing member 510 shown in FIG. 8, the upper portion 513 and the lower portion 514 may both be inclined and may have shapes with different inclination angles. Furthermore, like the sealing member 610 shown in FIG. 9, the upper part 613 and the lower part 614 may be inclined as a whole with an uneven shape. Further, like the sealing member 710 shown in FIG. 10, an upper inclined portion 713 a that is located around the inner penetrating portion and is inclined with respect to the penetrating direction so that the length in the penetrating direction becomes shorter toward the inner side, and the lower portion It may have a shape having an inclined flat portion 714a and an upper flat portion 713b that is not inclined outside the upper inclined portion 713a and a lower flat portion 714b that is not inclined outside the lower inclined portion 714a.

The sealing member only needs to have a portion where the compression ratio in the pressed direction is larger on the outer side than on the inner side in the pressed state. Here, about the to-be-pressed part in the use condition pressed among the sealing members, you may be comprised so that a part with a larger compression ratio may not arise inside than the outside.

Further, regarding the compression ratio of the sealing member, the inner side and the outer side of the sealing member are based on the center of the thickness in the inner and outer directions in the cross section including the line extending in the penetrating direction including the center of the penetrating portion inside the sealing member. The inner compression ratio is preferably smaller than the outer compression ratio, and the value obtained by subtracting the inner compression ratio from the outer compression ratio is preferably 2% or more and 60% or less. It is more preferably 3% or more and 50% or less, and further preferably 10% or more and 30% or less.

The overall compression ratio of the sealing member, not the compression ratio divided into the inside and the outside, is preferably 10% or more in order to reduce the influence of dimensional tolerance. Furthermore, 20% or more is preferable in order to maintain a high repulsive force for a long period.

Here, the compression ratio means a sealing member (or a state where no force is applied to the sealing member in a cross section including a line extending in the penetration direction including the center of the penetrating portion inside the sealing member (or The sealing member (or specifying the sealing member) in a state where the sealing member is pressed from one side and the other side in the penetrating direction and sealed with respect to the cross-sectional area of the specific part of the sealing member) The ratio of the reduced portion of the cross-sectional area (1—the cross-sectional area of the sealing member in the pressed state / the cross-sectional area of the sealing member in a state where no force is applied). This compression ratio is such that when the sealing member is pressed from one side and the other side in the penetrating direction and sealed (used state), the size of the sealing member simply decreases in the pressing direction. The value is obtained assuming that the dimensions do not change.

Further, in a cross section including a line extending in the penetrating direction including the center of the penetrating portion inside the sealing member, when the upper portion is configured by an inclined surface, the inclination angle of the surface is relative to the horizontal plane. It is preferably inclined at 5 degrees or more, more preferably at least 10 degrees, and further preferably at least 20 degrees.

(3) Material of sealing member The material of the sealing member is not particularly limited, and the upper limit of the tensile elastic modulus of the sealing member is preferably 0.8 in order to obtain the sealing effect by the sealing member for a longer time. GPa, more preferably 0.7 GPa. Further, the lower limit of the tensile modulus of the sealing member is preferably 0.3 GPa. The basis for the desirable range of the tensile modulus will be described later.

The material for the sealing member is not particularly limited, and rubbery substances, resins other than fluororesins, fluororesins, and mixtures thereof can be used. These materials are preferably contained as a main component of the sealing member.

Examples of rubbery substances include nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluoro rubber (FKM), perfluoro fluoro rubber (FFKM) silicone rubber (VMQ), ethylene propylene rubber (EPDM), and chloroprene rubber. (CR), acrylic rubber (ACM), butyl rubber (IIR), urethane rubber (U), natural rubber (NR), chlorosulfonated polyethylene rubber (CSM), and epichlorohydrin rubber (CO, ECO) At least one of the above can be used.

Examples of resins other than fluororesins include polyethylene (PE), polypropylene (PP), polycarbonate (PC), methacrylic resin, acrylonitrile / butadiene / styrene resin (ABS), polymethylpentene (PMP), and polystyrene (PA). At least one selected from the group consisting of polyethylene terephthalate (PET), melamine resin, phenolic resin, and unsaturated polyester resin can be used. For example, in the case of PP, the melt flow rate of a resin other than a fluororesin is a value measured at a temperature of 230 ° C. and a load of 2.16 kg according to ASTM D 1238, and is preferably 5 or more and 60 or less.

Fluororesin includes polytetrafluoroethylene (PTFE), tetrafluoroethylene (TFE) / hexafluoropropylene (HFP) copolymer (FEP), TFE / perfluoro (alkyl vinyl ether) (PAVE) copolymer (PFA) , Polyphenylene sulfide (PPS), ethylene (Et) / tetrafluoroethylene (TFE) copolymer, polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene (CTFE) / TFE copolymer, Et / CTFE copolymer , Polyvinylidene fluoride (PVdF), TFE / vinylidene fluoride (VdF) copolymer, VdF / HFP copolymer, and polyvinyl fluoride (PVF) can be used. .

Here, for example, when describing as “TFE / HFP copolymer”, it is a copolymer including a polymerized unit based on TFE (TFE unit) and a polymerized unit based on HFP (HFP unit). Means.

Here, when a part of the sealing member to be compressed is a surface and is inclined with respect to the surface of the member to be compressed, the surface to be contacted before compression is not parallel. For this reason, as a sealing member, what deform | transforms so that it may become parallel to the surface of the member of the side to deform | transform flexibly and compress is preferable. From such a viewpoint, as a material for the sealing member, a perfluoropolymer which is a relatively flexible resin is preferable, and among them, PTFE, PFA, and FEP are preferable. PAVE in PFA is preferably one having an alkyl group having 1 to 6 carbon atoms, more preferably perfluoromethyl vinyl ether (PMVE), perfluoro (ethyl vinyl ether) (PEVE) or perfluoropropyl vinyl ether (PPVE). The PFA has a PAVE unit of more than 2% by mass and preferably 8% by mass or less, and more preferably 2.5 to 6% by mass. The content of each monomer unit in these copolymers can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer (the same applies hereinafter). As long as the PFA has the above-mentioned composition, it may be obtained by polymerizing other monomers. Examples of other monomers include HFP. The content is preferably 1% by weight or less. One or more of the other monomers can be used. Among PFA, a TFE / PPVE copolymer is particularly preferable because of its excellent creep resistance. The copolymer composition of PPVE is preferably 2.0% by weight to 5.0% by weight. Here, it is also possible to add melt-flowable PTFE, apparently lower the PPVE content, improve creep resistance, and reduce compression set. In that case, the total PPVE content is preferably 1.0% by weight to 4.0% by weight. If the total PPVE content is less than 1% by weight, cracks are likely to occur, and if it exceeds 4% by weight, the effect of adding PTFE is reduced.

Further, when the sealing member is used as a gasket for a lithium ion battery, it is preferable that a material that hardly swells in a highly polar solvent and does not easily deteriorate due to contact is contained. Specifically, as a highly polar solvent, for example, LiCF ₃ SO ₃ , LiClO ₄ may be used in a nonaqueous solvent in which ethylene carbonate, propylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate or diethyl carbonate is appropriately mixed. And non-aqueous electrolyte obtained by dissolving LiBF ₄ and / or LiPF ₆ . Therefore, ETFE or perfluoropolymer is preferable as a material that hardly swells in these polar solvents and hardly deteriorates due to contact, and among the perfluoropolymers, PTFE, PFA, and FEP are preferable. Among these, since water vapor permeability is low, decomposition of electrolyte such as LiPF ₆ due to moisture can be suppressed, and it has sufficient hardness, solvent swellability is smaller than rubber, and a wide range of chemical substances In particular, PFA is preferable from the viewpoint of being resistant to chemicals and being resistant to oxidative degradation and enabling long-term use. When the sealing member contains PFA, the PFA content is preferably 50 wt% or more and 100 wt% or less, and the lower limit thereof is more preferably 70 wt% or more.

The above PTFE may be a TFE homopolymer or a modified PTFE. Here, “modified PTFE” is obtained by copolymerizing with TFE a small amount (1% by weight or less) of a comonomer (modifier) that does not impart melt processability to the resulting copolymer. means. Examples of the modifier include perfluoroolefins such as HFP; chlorofluoroolefins such as CTFE; trifluoroethylene, perfluoroalkyl vinyl ethers, and the like.

The above-mentioned TFE / VdF copolymer preferably has a TFE unit: VdF unit molar ratio of 45 to 85/55 to 15, more preferably 50 to 80/50 to 20.

The above-mentioned VdF / HFP copolymer preferably has a molar ratio of VdF units to HFP units of 45 to 85/55 to 15, more preferably 50 to 80/50 to 20, and still more preferably 60-80 / 40-20. The VdF / HFP copolymer is a copolymer containing a polymer unit based on VdF and a polymer unit based on HFP, and may have a polymer unit based on another fluorine-containing monomer. For example, VdF / HFP / TFE copolymer is also a preferred form. The VdF / HFP / TFE copolymer preferably has a VdF / HFP / TFE molar ratio of 40 to 80/10 to 35/10 to 25.

When the sealing member contains a perfluoropolymer, the melt flow rate (MFR) is preferably 40 g / 10 min or less, and preferably 10 g / 10 min or less, from the viewpoint that it is difficult to flow and the repulsive force is easily secured. More preferably, it is 3 g / 10 min or less. Here, MFR refers to the melt flow rate of the polymer at 372 ° C. In accordance with ASTM D 1238-98, a melt index tester (manufactured by Toyo Seiki Seisakusho) is used, and about 6 g of resin is maintained at 372 ° C. After putting it in a cylinder and letting it stand for 5 minutes, the temperature reaches an equilibrium state, and then the resin is extruded through an orifice with a diameter of 2.1 mm and a length of 8 mm under a 5 kg piston load for a unit time (usually 10 to 60 seconds) ) Is measured three times for the same sample, and the average value is the value converted into the amount of extrusion per 10 minutes (unit: g / 10 minutes).

Of the fluororesins mentioned above, from the viewpoint of excellent melt processability, FEP, PFA, Et / TFE copolymer, PCTFE, CTFE / TFE copolymer, Et / CTFE copolymer, PVdF, TFE / VdF It is preferably at least one selected from the group consisting of a copolymer, a VdF / HFP copolymer, and PVF. By using such a melt processable fluororesin, molding can be easily performed.

(4) Simulation In the pressed state, the sealing member of the present invention has a portion in which the compression ratio in the pressed direction is larger on the outside than on the inside, so that the sealing member is used. Even after a long time (for example, 200,000 hours) has passed, the repulsive force of the sealing member tends to remain, and the sealing effect can be maintained satisfactorily.

Here, as an example of the sealing member according to the present invention, the sealing member 10 shown in FIG. 4 and the sealing member 10X shown in FIG.

The sealing member 10 shown in FIG. 4 is an example in which the width in the penetration direction increases toward the outside, and both the upper surface 13 side and the lower surface 14 side are inclined at an inclination angle α with respect to the horizontal plane. is there.

Further, the sealing member 10X shown in FIG. 5 has a shape in which the width in the penetrating direction increases toward the outside. The upper surface 13x is inclined at an inclination angle α with respect to the horizontal plane, and the lower surface 14x is horizontal. This is an example of spreading upward.

Moreover, in the simulation, the sealing member 10Y shown in FIG. 11 and the sealing member 10Z shown in FIG. 12 were used as comparative objects that are not the sealing member according to the present invention. The sealing member 10Y shown in FIG. 11 has a shape in which the upper surface 13y is positioned downward and the lower surface 14y is positioned upward and the width in the penetrating direction decreases toward the outer side. Both are inclined at an inclination angle β with respect to the horizontal plane. The sealing member 10Z shown in FIG. 12 has a lower surface 14z that spreads out on a horizontal plane, and the upper surface 13z has a shape in which the width in the penetrating direction decreases toward the outer side as it is located on the lower side, and the upper surface 13z. Is inclined at an inclination angle β with respect to the horizontal plane.

In addition, the sealing

members

10, 10X, 10Y, and 10Z used in the simulation are all annular, the inner penetrating portion is cylindrical, the inner diameter A is 6 mm, and the outer peripheral surface is also cylindrical. The same outer diameter B of 18 mm was used. Further, these sealing

members

10, 10X, 10Y, and 10Z have a width C in the penetrating direction at the center position of the horizontal width (the intermediate position between the inner circumference and the outer circumference in the radial direction) of 5 mm. Made common.

The simulation is performed under the condition that the sealing member is pressed by a rigid body from both one side and the other side in the penetration direction by a member having a horizontally extending surface in an environment of 60 ° C. and held as it is. , Using ANSYS V14.5. The pressing is performed until the width C in the penetration direction at the center position of the horizontal width of the sealing member (the intermediate position between the inner circumference and the outer circumference in the radial direction) becomes 3 mm, and this 3 mm is maintained. did.

Here, the materials of the sealing

members

10, 10 X, 10 Y, and 10 Z used for the simulation are all “copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether”, and specifically, NEOFRON (registered trademark) PFA The physical property values of AP-230 were used. Here, as physical properties of PFA AP-230, the MFR according to ASTM2.0D3307 is 2.0g / 10min, the melting point is 306 ℃ according to ASTM D4591, and the specific gravity according to ASTM D3307 is 2.14. The tensile strength according to ASTM D 3307 is 34.0 MPa, and the elongation according to ASTM D 3307 is 320%. The tensile modulus is 430 MPa. The physical property value at 60 ° C used for the simulation is a value measured by changing only the measurement atmosphere temperature of ASTM D 307 3307 to 60 ° C, the tensile strength is 23.5 MPa, the elongation is 330%, the tensile modulus is 186.1 MPa, The yield stress was assumed to be 3.42 MPa. The Poisson's ratio was assumed to be 0.46.

Here, the condition of the material used over time was determined using the creep characteristics of the PFA AP-230 used. The creep characteristics were assumed to be expressed by a modified time hardening type creep model as shown in the following equation. An AP230 11.3mmφ × 10L test piece was cut from a compression-molded block, and the creep characteristics under load of 6.9MPa, 14MPa, 20MPa, 30MPa and 40MPa were measured at 60 ℃. Using the measured values, C ₁ , C ₂ , C ₃ , and C ₄ were obtained by fitting the measured data to the following formula 1.

The coefficient of friction between the sealing member and the rigid body used for pressing from one side and the other side in the penetration direction was set to 0.1.

In addition, the diagram which shows the relationship between the nominal stress and the nominal strain shown in FIG. 13 was obtained by conducting a tensile test on the material used. Moreover, the diagram which shows the relationship between the true stress shown in FIG. 14 and a true distortion | strain was obtained by calculating based on the diagram of FIG. And from these diagrams, simulation conditions for aged behavior analysis were obtained.

In the simulation, even when the restraining member 20 assumed as a rigid body shown in FIG. 1 is provided outside the outer periphery of each of the sealing

members

10, 10X, 10Y, and 10Z and pressed from the penetration direction, the outer periphery is An example in which the constraint condition was set so as not to spread outward and an example in which the spread at the outer periphery was free without using such a constraint member 20 were studied.

FIG. 15 shows a simulation result regarding the magnitude of the repulsive force after 200,000 hours of the sealing member when the inclination angles α and β are changed.

As shown in FIG. 15, in any sealing

member

10, 10X, 10Y, 10Z, more repulsive force remains after 200,000 hours when the restraining member 20 is used, and the sealing effect Is found to be good. Further, for the sealing

members

10Y and 10Z whose thickness in the penetrating direction decreases toward the outside, the repulsive force remaining after 200,000 hours is not improved even if the inclination angle β increases. As for the sealing member 10X in which only the upper surface side is inclined, the repulsive force becomes slightly better as the inclination angle α increases, and the repulsive force becomes maximum within the range of the inclination angle of 15 degrees or more and 22 degrees or less. For the sealing member 10 having a shape in which the thickness in the penetration direction increases toward the outside, it can be confirmed that the repulsive force remaining after 200,000 hours becomes better as the inclination angle α increases, and the sealing member 10X The effect was remarkable compared with. Whether or not the restraining member 20 is present, the repulsive force is improved by increasing α.

As described above, as the sealing member, a member having a shape in which the thickness in the penetrating direction is increased toward the outer side and both the upper surface 13 and the lower surface 14 are inclined as in the case of the sealing member 10. It can be seen that it is desirable to be used in the presence of.

FIG. 16 shows a simulation result showing a change in the repulsive force according to the elapsed time from the start of use of the sealing member. Here, a flat plate-shaped plate having no inclination (an example of “no inclination”) was also used for comparison.

According to the results shown in FIG. 16, for any of the sealing

members

10, 10X, 10Y, and 10Z, the reduction in the repulsive force with the passage of time is gentler when the restraining member 20 is used. It can be seen that the sealing effect is better when 20 is present.

Further, among the above-described physical properties of the sealing member, a simulation was performed on a material obtained by doubling the stress during the tensile test and the repulsion force of the creep. Here, the simulation was performed on the assumption that the amount of creep when the load twice the actual measurement was applied was the same. In addition, simulation data was created on the assumption that twice as much stress as actually measured was generated for a certain amount of deformation.

FIG. 17 shows the simulation results of the temporal change of the repulsive force when the stress and creep repulsive force of the material used for the sealing member are 1 and 2 times.

According to the result of FIG. 17, the model with a repulsive force of 2 times is preferable at the beginning, but the difference between the repulsive force with the repulsive force of 1 time and that of the rebound force disappears in about 1 hour, and then it is rather 1 time. It was found that the repulsive force of the thing is largely maintained. As a physical property value of the material of the sealing member, there is a tensile elastic modulus as a physical property value highly dependent on the repulsive force. The tensile elastic modulus at room temperature is 0.86 GPa in the model where the repulsive force is twice, and those having a tensile elastic modulus of 0.86 GPa are not preferable because the repulsive force is too large. Therefore, the tensile elastic modulus of the material is preferably smaller than 0.8 GPa and more preferably 0.7 GPa or less.

Further, the repulsive force after 200,000 hours when the coefficient of friction with the pressed portion in contact with the sealing member is changed is expressed by the sealing member 10 (inclination angle α = 10 degrees), 10X (inclination angle α = 20 degrees). ) A simulation was performed for 10Y (inclination angle β = 10 degrees) and 10Z (inclination angle β = 20 degrees). Here, the conditions of each sealing member were as described above except for the conditions relating to the coefficient of friction with the member to be pressed. The simulation result is shown in FIG. As this result shows, it became clear that the coefficient of friction with the pressing member in contact with the sealing member affects the magnitude of the repulsive force from the sealing member. According to this result, it became clear that the repulsive force obtained becomes large, so that the said friction coefficient becomes large. This effect was the same in any of the sealing

members

10, 10X, 10Y, and 10Z regardless of the shape of the sealing member. Moreover, the increase ratio of the repulsive force due to the increase of the friction coefficient was almost the same ratio regardless of the short and long elapsed time. For example, when the friction coefficient was changed from 1.0 to 2.0, the repulsive force increased by about 25%.

Further, among the above sealing members, when the cylindrical shape having no inclination on the upper surface and the lower surface is pressed from one side and the other side in the penetrating direction and the thickness of 5 mm is maintained as 3 mm, Under the condition that there is no constraint, a simulation was performed to obtain the change over time of the repulsive force according to the radial position.

The results of the simulation are shown in FIG. 19 for the state immediately after pressing, in FIG. 20 for the state after 10,000 hours have been pressed, and in FIG. 21 for the state after 100,000 hours have been pressed and 20 Each state after 10,000 hours is shown in FIG. 19 to 22 show a part of the side cross section of the sealing member, the left side of the figure is the radially inner side, and the right side of the figure is the radially outer side. In FIGS. 19 to 22, different repulsive force regions are indicated by different hatchings.

Here, the surface pressure value of the portion where the repulsive force is the maximum immediately after pressing is 37.7 MPa, and the surface pressure value of the portion where the repulsive force is maximum after 10,000 hours with the pressure being pressed is 37.7 MPa. The surface pressure value of the portion where the repulsive force is maximum is 15.0 MPa when 100,000 hours have passed while pressing, and the repulsive force is maximum when 200,000 hours have passed with pressing. The surface pressure of a certain part was 14.7 MPa.

According to this, as shown in FIGS. 19 to 22, the sealing member (indicated by the alternate long and short dash line) in which the upper surface and the lower surface are not inclined is pressed and deformed from the vertical direction (indicated by the alternate long and two short dashes line) ) Is maintained, it can be seen that the repulsive force outside the sealing member when 200,000 hours have elapsed has decreased. In addition, in the shape in which the thickness in the penetrating direction does not increase toward the outside, and the shape is not provided with an inclination, the outer diameter of the portion around the radially outer side is longer by being expanded outward in the pressed state. It is considered that the repulsive force in the penetrating direction is likely to be weakened. On the other hand, when the sealing member is used in such a manner that the outer side in the radial direction is constrained, it is difficult for such a deformation to increase the outer diameter during pressing, so that the reduction of the repulsive force is suppressed. Can be considered.

(5) Usage example FIG. 23 shows an example of the state before pressing, and FIG. 24 shows an example of the pressing usage state when the gasket 51 is used as a sealing member around the electrode of the battery.

A through portion penetrating in the vertical direction is provided in the upper cover 63 of the battery and the insulating cover 62 covering a part of the upper cover 63. A caulking pin 61 that is used as an electrode or the like by caulking is provided in the penetrating portion. The caulking pin 61 is made of metal and has a pin upper portion 61a and a pin lower portion 61b which are connected to each other and integrated.

As shown in FIG. 23, the pin upper portion 61a of the caulking pin 61 has a cylindrical shape with an outer diameter smaller than the inner diameter of the penetrating portion, as shown in FIG. It has a shape extending in the vertical direction to the height above the upper lid 63 via the inside.

As shown in FIG. 23, the pin lower portion 61b of the caulking pin 61 has a cylindrical shape with an outer diameter larger than the inner diameter of the penetrating portion, and further from the lower end of the pin upper portion 61a below the upper lid 63, as shown in FIG. It has a shape that extends downward. The pin lower portion 61b of the caulking pin 61 is covered from the periphery in the radial direction by a restraining member 64 made of a highly rigid member. The restraining member 64 is positioned by being fixed by another member (not shown) so as not to move relative to the upper lid 63, for example.

The gasket 51 is provided so as to be interposed between the upper lid 63, the insulating cover 62, the restraining member 64, and the caulking pin 61, and has an upper cylindrical portion 51a, a disc portion 51b, and a lower cylindrical portion 51c. ing.

The upper cylindrical portion 51a has an outer diameter that is slightly smaller than the inner diameter of the through portion inside the upper lid 63 and the insulating cover 62, and an inner diameter that is slightly larger than the outer diameter of the pin upper portion 61a of the caulking pin 61. It has a shape extending in the vertical direction from a height below 63 to a height above the upper lid 63 through the inside of the penetrating portion. The upper cylindrical portion 51 a is interposed between the upper lid 63 and the insulating cover 62 and the pin upper portion 61 a of the caulking pin 61 to insulate them from each other.

The lower cylindrical portion 51 c has an inner diameter that is slightly larger than the outer diameter of the pin lower portion 61 b of the caulking pin 61 and an outer diameter that is slightly smaller than the inner diameter of the restraining member 64. The restraint member 64 has a shape extending upward from the height position where the inner periphery of the restraining member 64 faces toward the lower surface of the upper lid 63. The lower cylindrical portion 51 c is interposed between the pin lower portion 61 b of the caulking pin 61 and the restraining member 64 to insulate them from each other.

The disc portion 51b is a member that expands so as to connect the lower end outer peripheral portion of the upper cylindrical portion 51a and the lower cylindrical portion 51c upper end inner peripheral portion in the radial direction. For example, like the sealing member 10 described above Make up shape. The radially outer end portion of the disc portion 51b has an outer upper flat surface portion that makes surface contact with the lower surface of the upper lid 63 and an outer lower flat portion that makes surface contact with the upper surface portion of the pin lower portion 61b of the caulking pin 61. . Of the disc portion 51b, the radially inner portion of the outer upper flat portion and the outer lower flat portion has a configuration in which the upper surface and the lower surface are inclined so that the thickness in the vertical direction becomes thinner toward the radially inner side. Yes. Although not particularly limited, in this usage example, the thickness in the vertical direction is continuously reduced from the radially outer side toward the radially inner side until reaching the outer periphery of the lower end of the upper cylindrical portion 51a. However, for example, a portion where the thickness in the vertical direction is constant immediately before reaching the outer periphery of the lower end of the upper cylindrical portion 51a may be provided. Further, in the radial direction of the disc portion 51b, the ratio of the length in the radial direction between the portion where the outer upper plane portion and the outer lower plane portion are provided and the portion inside the portion is not particularly limited. However, for example, in the state before being caulked as shown in FIG. 23, the range of 1: 9 to 5: 5 is preferable.

23, the upper end of the pin upper portion 61a of the caulking pin 61 is moved downward with the gasket 51 being restrained from moving in the radial direction by the restraining member 64. By crushing the pin, the pin upper portion 61a of the caulking pin 61 is crushed and deformed so as to cover the upper end of the upper cylindrical portion 51a of the gasket 51 from above as in the deformed pin upper portion 61a ′ shown in FIG. At this time, the disc portion 51b of the gasket 51 is pressed from above and below by the lower surface portion of the upper lid 63 and the upper surface portion of the pin lower portion 61b of the caulking pin 61, and is deformed so that the thickness in the vertical direction is reduced. In this way, the gasket 51 is fixed in a state in which it is pressed in the up-down direction while being constrained in the radial direction, and is in use. Here, the upper cylindrical portion 51a of the gasket 51 is also deformed so as to have a shorter vertical length.

In addition, in the state after crimping as shown in FIG. 24, the portion provided with the outer upper flat portion and the outer lower flat portion in the radial direction of the disc portion 51b of the gasket 51, and the inner portion of the portion. The ratio of the length in the radial direction is not particularly limited, but is preferably 7: 3 to 9.5: 1, for example.

The sealing member according to the present invention is particularly useful when used, for example, as a gasket or the like because a good sealing effect can be obtained even when used for a long time.

10, 10X, 110, 210, 310, 410, 510, 610, 710 Sealing member 11 Cylindrical part 111 Square part 211

Perforated part

12, 112, 212

Outer periphery

13, 13x, 13y,

13z Upper surface

313, 413, 513 , 613 Upper part 713a Upper inclined part 713b Upper

flat part

14, 14x, 14y, 14z Lower surface 714a Lower inclined part 714b Lower

flat part

314, 414, 514, 614 Lower part 20 Restraining member 51 Gasket 51a Upper cylindrical part 51b Disc part 51c Lower cylindrical part 61 Caulking pin 61a Pin upper part 61a 'Deformation pin upper part 61b Pin lower part 62 Insulation cover 63 Upper lid 64 Constraining member

JP 2013-157155 A

Claims

An annular sealing member,
Used in a state where it is pressed from one side and the other side in the penetrating direction in the inner penetrating part,
In the pressed state, the compression ratio in the pressed direction has a portion where the outside is larger than the inside,
Sealing member.
The thickness in the pressed direction increases from the inside toward the outside.
The sealing member according to claim 1.
The tensile modulus is 0.8 GPa or less,
The sealing member according to claim 1 or 2.
Composed of perfluoropolymer,
The sealing member according to any one of claims 1 to 3.
The content of PFA is 50 wt% or more and 100 wt% or less,
The sealing member according to claim 4.
Used for battery gaskets,
The sealing member according to any one of claims 1 to 5.