JP2022139905A - Gasket member and manufacturing method for gasket member - Google Patents

Abstract

To provide a gasket member capable of suppressing the risk of liquid leakage inside a battery.SOLUTION: A gasket member for a cylindrical battery seals an opening of a battery can. The gasket member includes a cylindrical support portion that supports a collector rod provided inside the battery can, an outer peripheral portion that is supported by the battery can, and an annular intermediate portion formed between the support portion and the outer peripheral portion on the support portion side. Further, the gasket member includes a cushioning portion that is formed between the intermediate portion and the outer peripheral portion and allows the outer peripheral portion to be elastically deformable with respect to the intermediate portion, and a low water absorption layer formed on the flat surface of the annular intermediate portion.SELECTED DRAWING: Figure 2

Description

The present invention relates to a gasket member and a method for manufacturing the gasket member.

A cylindrical battery includes a cylindrical battery can, a positive electrode material stored in the battery can, a negative electrode material stored in the battery can, and a cylindrical separator member separating the positive electrode material and the negative electrode material. and a gasket member for sealing the opening of the battery can on the side of the negative electrode terminal.

The gasket member includes a cylindrical support portion that supports a collector rod provided inside the battery can, an outer peripheral portion that is supported by the battery can, an annular safety valve formed along the outer periphery of the support portion, and a safety valve. and an annular intermediate portion formed on the side of the safety valve between and the outer peripheral portion. Further, the gasket member has a cushioning portion formed between the intermediate portion and the outer peripheral portion and elastically deformable with respect to the outer peripheral portion and the intermediate portion. The safety valve is a thin portion that is broken by the pressure of the gas inside the battery can. Moreover, the gasket member is made of a material such as nylon.

Japanese Patent Publication No. 2010-534399

Cylindrical batteries such as alkaline batteries use, for example, a potassium hydroxide aqueous solution as an electrolyte, and have the property of absorbing moisture due to the deliquescence of potassium. Therefore, if the gasket member made of a material such as nylon allows water to permeate into the battery from the outside, and the amount of water increases, the internal pressure of the battery increases and the risk of liquid leakage may occur.

However, if a material with a low moisture permeability is used for the entire gasket member, it may be damaged due to cushioning during processing, which may affect the function of the safety valve. In addition, under the storage environment of the battery, if the gasket member becomes brittle and the internal pressure of the battery rises, the flat surface of the middle part will crack instead of the safety valve, increasing the risk of liquid leakage in which solids inside the battery flow out.

The disclosed technology has been made in view of the above, and an object thereof is to provide a gasket member or the like capable of suppressing the risk of liquid leakage occurring inside the battery.

One aspect of the gasket member disclosed in the present application is a gasket member for a cylindrical battery that seals an opening of a battery can. The gasket member is formed on a cylindrical support portion that supports a collector rod provided inside the battery can, an outer peripheral portion that is supported by the battery can, and a support portion side between the support portion and the outer peripheral portion. and an annular middle portion. Further, the gasket member includes a cushioning portion formed between the intermediate portion and the outer peripheral portion to allow the outer peripheral portion to be elastically deformable with respect to the intermediate portion, and a low water absorption layer formed on the flat surface of the annular intermediate portion. have

According to one aspect of the gasket member disclosed in the present application, the risk of liquid leakage inside the battery can be suppressed.

FIG. 1 is a vertical cross-sectional view showing a cylindrical battery of an embodiment. FIG. 2 is a vertical cross-sectional view showing the essential parts of the cylindrical battery of the example. FIG. 3 is a cross-sectional view showing the gasket member before crimping.

Hereinafter, embodiments of the gasket member and the like disclosed in the present application will be described in detail based on the drawings. The gasket member disclosed in the present application is not limited to the following examples.

(Structure of Cylindrical Battery)
FIG. 1 is a longitudinal sectional view showing a cylindrical battery 1 of an embodiment. As shown in FIG. 1, the cylindrical battery 1 of the embodiment is, for example, an aqueous primary battery, a so-called dry battery. A cylindrical battery 1 includes a cylindrical battery can 3 having an opening 3a, a collector rod 4, a positive electrode material 5, a negative electrode material 6, a separator member 7 for partitioning the positive electrode material 5 and the negative electrode material 6, and a battery can. and a gasket member 8 for sealing the opening 3a of 3. The cylindrical battery 1 also has a positive electrode terminal 11 formed at one end of the battery can 3 and a negative electrode terminal 12 disposed at the other end of the battery can 3 as electrode terminals.

A positive electrode terminal 11 is integrally formed at one end of the battery can 3 . At the other end of the battery can 3, a beaded portion (beading portion) 3b is formed along the outer circumference of the battery can 3. As shown in FIG. A negative electrode terminal 12 and a gasket member 8 are provided in the constricted portion 3b of the battery can 3 so as to block the opening 3a. The collector bar 4 is arranged in the center of the battery can 3 . The collector rod 4 has a base end supported by a gasket member 8 and a tip end extending toward the positive electrode terminal 11 side. The collector bar 4 is made of, for example, brass.

The negative electrode material 6 is a cylindrical material provided around the collector rod 4 inside the battery can 3 and loaded inside the separator member 7 . Further, as the negative electrode material 6, for example, a gel-like negative electrode mixture containing zinc as a main component is used. The positive electrode material 5 is loaded inside the battery can 3 along its inner peripheral surface. The positive electrode material 5 is provided on the outer peripheral side of the negative electrode material 6 housed inside the battery can 3 with the separator member 7 interposed therebetween. A ring-shaped positive electrode mixture, for example, is used as the positive electrode material 5 , and a plurality of ring-shaped positive electrode mixtures are stacked and arranged along the axial direction of the current collector rod 4 . The separator member 7 is formed of, for example, a nonwoven fabric or the like in a cylindrical shape, and is arranged inside the positive electrode material 5 and along the axial direction of the current collector rod 4 .

(Structure of gasket member)
FIG. 2 is a vertical cross-sectional view showing the essential parts of the cylindrical battery 1 of the embodiment. FIG. 3 is a cross-sectional view showing the gasket member 8 before crimping. As shown in FIG. 2, the gasket member 8 of the tubular battery 1 includes a cylindrical support portion 15 that supports one end of the current collector rod 4, and an annular safety valve 16 formed along the outer periphery of the support portion 15. , and an annular outer peripheral portion 17 supported by the opening 3 a of the battery can 3 . In addition, the gasket member 8 includes an annular intermediate portion 18 formed on the side of the safety valve 16 between the safety valve 16 and the outer peripheral portion 17, and an annular intermediate portion 18 formed between the intermediate portion 18 and the outer peripheral portion 17. and a cushioning portion 19 that is elastically deformable with respect to the portion 18 . The gasket member 8 also has an annular low water absorption layer 21 formed on the flat surface 20 of the intermediate portion 18 on the negative electrode terminal 12 side of the battery can 3 .

The support portion 15 has a support hole 15a through which the collector rod 4 is passed, and as shown in FIG. The gasket member 8 is supported by the battery can 3 by crimping the outer peripheral portion 17 between the vicinity of the constricted portion 3 b of the battery can 3 and the outer peripheral portion of the negative electrode terminal 12 .

As shown in FIG. 2 , the end of the separator member 7 is abutted against the intermediate portion 18 , and the space containing the negative electrode material 6 is blocked by the separator member 7 . The safety valve 16 is a groove-shaped thin portion that is broken by the pressure of the internal gas of the battery can 3 .

The buffer portion 19 is formed between the intermediate portion 18 and the outer peripheral portion 17 and arranged on the outer peripheral side of the separator member 7 . The cushioning portion 19 extends from the outer peripheral portion 17 in the axial direction of the current collecting rod 4 and is folded back to be connected to the intermediate portion 18, thereby forming a fold-like protrusion having a bottom portion 19a.

The buffer portion 19 of the gasket member 8 is laterally tightened, and the outer peripheral portion 17 of the gasket member 8 is sandwiched between the vicinity of the constricted portion 3b of the battery can 3 and the outer peripheral portion of the negative electrode terminal 12, so that the outer peripheral portion 17 is clamped. The intermediate portion 18 is elastically deformed from the state shown in FIG. 3 to the state shown in FIG. That is, the gasket member 8 is bent in the diameter direction after the opening 3a of the battery can 3 is sealed.

The low water absorption layer 21 formed on the flat surface 20 of the intermediate portion 18 is, for example, a layer made of a hard resin having a water absorption of 0.6% (saturated for 24 hours) or less. Further, the low water absorption layer 21 is, for example, a hard layer having a Rockwell hardness of R120 or higher. Furthermore, the thickness of the low water absorption layer 21 is, for example, 0.3 mm to 1.0 mm. The low water absorption layer 21 suppresses the permeation of moisture from the outside of the battery can 3 to reduce the permeation of moisture into the battery can 3, and reduces the increase in the internal pressure of the battery can 3 due to the intrusion of moisture. The occurrence of liquid leakage due to embrittlement of 8 can be suppressed.

Therefore, the applicant investigated the water permeation, water absorption rate, embrittlement, and valve operation of the safety valve 16 in the gasket member 8 when the low water absorption layer 21 made of various materials was formed on the flat surface 20 of the intermediate portion 18 of the gasket member 8. verified. (Table 1) summarizes various verification results in a table.

First, on the flat surface 20 of the gasket member 8 made of 6.12 nylon, an LR6 gasket coated with PAI (polyamide-imide) having a thickness of 0.5 mm was prepared. As the material of the low water absorption layer formed on the flat surface 20, for example, a resin having a Rockwell hardness (measured based on ASTM standard D785) higher than nylon and a water absorption rate (measured based on ASTM standard D570) is low. selected. As the resin, for example, PEEK (polyether ethyl ketone), PAI (polyamideimide), or PI (polyimide) was used.

Then, Tests 1 to 3 were performed on the gasket member under each condition, and the test results were verified. Test 1 is a test of moisture permeation (n=20). Stored in an environment of 60°C and 90% R.H. for 100 days, ○ (suitable) when permeated water content is 30 mg or less, △ when permeated water content is 31 to 99 mg, and 100 mg or more It was judged as × (not suitable). The test result of Test 1 is the test result of water permeation.

Also, Test 2 is a test of embrittlement (n=20). Stored in an environment of 60°C and 90% R.H. for 100 days, and in the misuse charging test based on JIS C 8514, ○ when only the safety valve 16 was operated, and the breakage of the flat surface 20 was 5% to 50%. It was judged as Δ when the flat surface 20 was ruptured by 55% to 100% or when solid matter inside the battery can 3 flowed out. The test result of test 2 is the embrittlement test result.

Test 3 is a valve actuation pressure measurement test of the valve actuation of the safety valve 16 (n=20). A case where the safety valve 16 operated normally was evaluated as ◯, and a case where the safety valve 16 did not operate normally was evaluated as x. The test results of test 3 are the valve operation test results.

First, the conventional gasket member does not have the low water absorption layer 21 on the flat surface 20 . In this case, the test result of water permeation in the conventional gasket member is ×, the water absorption rate is 0.60%, the embrittlement test result is Δ, and the valve actuation test result is ◯.

In the gasket member 8 of Example 1, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PEEK, the thickness of the low water absorption layer 21 is 0.5 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R120. In this case, the water permeation test result of the gasket member 8 of Example 1 is ◯, the water absorption rate is 0.50%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 2, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PI, the thickness of the low water absorption layer 21 is 0.5 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R126. In this case, the water permeation test result of the gasket member 8 of Example 2 is ◯, the water absorption rate is 0.40%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member of Comparative Example 1, a low water absorption layer is formed on the flat surface, the material of the low water absorption layer is PAI, the thickness of the low water absorption layer is 0.1 mm, and the Rockwell hardness of the low water absorption layer is R127. In this case, the gasket member of Comparative Example 1 had a moisture permeation test result of x, a water absorption rate of 0.60%, an embrittlement test result of Δ, and a valve actuation test result of ◯.

In the gasket member of Comparative Example 2, a low water absorption layer is formed on the flat surface, the material of the low water absorption layer is PAI, the thickness of the low water absorption layer is 0.2 mm, and the Rockwell hardness of the low water absorption layer is R127. In this case, the gasket member of Comparative Example 2 had a water permeation test result of Δ, a water absorption rate of 0.55%, an embrittlement test result of ◯, and a valve actuation test result of ◯.

In the gasket member 8 of Example 4, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.3 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 4 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 5, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.4 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 5 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 3, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.5 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 3 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 6, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.6 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 6 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 7, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.7 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 7 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 8, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.8 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 8 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 9, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 0.9 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 9 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member 8 of Example 10, the low water absorption layer 21 is formed on the flat surface 20, the material of the low water absorption layer 21 is PAI, the thickness of the low water absorption layer 21 is 1.0 mm, and the low water absorption layer 21 is made of Rockwell hardness. Let the height be R127. In this case, the water permeation test result of the gasket member 8 of Example 10 is ◯, the water absorption rate is 0.33%, the embrittlement test result is ◯, and the valve actuation test result is ◯.

In the gasket member of Comparative Example 3, a low water absorption layer is formed on the flat surface, the material of the low water absorption layer is PAI, the thickness of the low water absorption layer is 1.1 mm, and the Rockwell hardness of the low water absorption layer is R127. In this case, the test result of moisture permeation in the gasket member of Comparative Example 3 is ◯, the water absorption rate is 0.33%, the test result of embrittlement is ◯, and the thickness of the low water absorption layer is too thick, so the test result of valve operation is x.

In the gasket member of Comparative Example 4, a low water absorption layer is formed on the flat surface, the material of the low water absorption layer is PAI, the thickness of the low water absorption layer is 1.2 mm, and the Rockwell hardness of the low water absorption layer is R127. In this case, the test result of water permeation in the gasket member of Comparative Example 4 is ◯, the water absorption rate is 0.33%, the test result of embrittlement is ◯, and the thickness of the low water absorption layer is too thick, so the test result of valve operation is x.

With the resin selected this time, when the low water absorption layer 21 was thickened to 1.1 mm or more, the flat surface 20 could not buffer, and the safety valve 16 did not operate normally. However, when the low water absorption layer 21 was set to have a thickness of, for example, 0.3 mm to 1.0 mm, good verification results were obtained in all tests of moisture permeation, embrittlement and valve actuation.

(Manufacturing process of gasket member)
A manufacturing process of the gasket member 8 will be described in order of process.
(1) A cylindrical support portion 15 that supports the collector rod 4 provided inside the battery can 3, an outer peripheral portion 17 that is supported by the battery can 3, and support between the support portion 15 and the outer peripheral portion 17. A gasket having an annular intermediate portion 18 formed on the portion 15 side and a cushioning portion 19 formed between the intermediate portion 18 and the outer peripheral portion 17 to allow the outer peripheral portion 17 to be elastically deformable with respect to the intermediate portion 18. Member 8 is formed from 6.12 nylon.
(2) A low water absorption layer 21 is formed from a cured resin on the flat surface 20 of the intermediate portion 18 of the gasket member 8 .

As a result, the gasket member 8 having the low water absorption layer 21 formed on the flat surface 20 of the intermediate portion 18 is manufactured.

(Manufacturing process of cylindrical battery 1)
Manufacturing steps of the cylindrical battery 1 configured as described above will be described in order of steps.
(1) For example, electrolytic manganese dioxide, graphite, a binder, and a potassium hydroxide solution are used to prepare a positive electrode mixture as the positive electrode material 5, and the positive electrode mixture is formed into a ring shape.
(2) A gel-like negative electrode mixture as the negative electrode material 6 is prepared using a zinc alloy powder, an electrolytic solution, and the like.
(3) A ring-shaped positive electrode mixture is accommodated inside the battery can 3 .
(4) A constricted portion 3 b is formed at the end of the battery can 3 by beading, and a sealant is applied to the contact surface between the gasket member 8 and the battery can 3 .
(5) The separator member 7 is inserted inside the positive electrode mixture accommodated in the battery can 3 .
(6) The separator member 7 is impregnated with a potassium hydroxide electrolyte.
(7) A gel-like negative electrode mixture is injected into the separator member 7 provided in the battery can 3 through the opening 3a on the negative electrode terminal 12 side.
(8) A collector is made by assembling the gasket member 8, the collector rod 4, and the negative electrode terminal 12 together.
(9) By assembling the current collector into the opening 3a of the battery can 3 and crimping the gasket member 8 of the current collector against the opening 3a of the battery can 3 from the lateral direction, which is the diameter direction of the gasket member 8, The gasket member 8 seals the opening 3a.

(Effect of Example)
In the tubular battery 1 of this embodiment, the opening 3 a of the battery can 3 is sealed with the gasket member 8 having the low water absorption layer 21 formed on the flat surface 20 of the annular intermediate portion 18 . As a result, the permeation of moisture from the outside of the battery can 3 is suppressed, thereby reducing the permeation of moisture into the interior of the battery can 3 . Furthermore, it is possible to suppress the leakage of liquid inside the battery due to embrittlement of the gasket member 8 while reducing the increase in the internal pressure of the battery can 3 due to permeation of moisture.

REFERENCE SIGNS LIST 1 Cylindrical battery 3 Battery can 3a Opening 4 Current collector 8 Gasket member 15 Supporting part 16 Safety valve 17 Peripheral part 18 Intermediate part 19 Buffer part 20 Flat surface 21 Low water absorption layer

Claims (7)

A gasket member for a cylindrical battery that seals an opening of a battery can,
a cylindrical support that supports a collector rod provided inside the battery can;
an outer peripheral portion supported by the battery can;
an annular intermediate portion formed on the support portion side between the support portion and the outer peripheral portion;
a cushioning portion formed between the intermediate portion and the outer peripheral portion, the buffer portion allowing the outer peripheral portion to be elastically deformable with respect to the intermediate portion;
a low water absorption layer formed on the flat surface of the annular intermediate portion;
A gasket member comprising: The low water absorption layer is
2. The gasket member according to claim 1, wherein the gasket member is formed on the flat surface of the annular intermediate portion on the negative terminal side of the battery can. The low water absorption layer is
3. The gasket member according to claim 1, wherein the layer is made of a material having a water absorption rate of 0.6% (saturated for 24 hours) or less. The low water absorption layer is
The gasket member according to any one of claims 1 to 3, wherein the hard layer has a Rockwell hardness of R120 or more. The thickness of the low water absorption layer formed on the flat surface is
The gasket member according to any one of claims 1 to 4, characterized in that it has a thickness of 0.3 mm to 1.0 mm. The material of the gasket member is
The gasket member according to any one of claims 1 to 5, characterized in that it is made of 6.12 nylon. A method for manufacturing a gasket member for a cylindrical battery that seals an opening of a battery can, comprising:
A cylindrical support portion that supports a collector rod provided inside the battery can, an outer peripheral portion supported by the battery can, and a support portion side formed between the support portion and the outer peripheral portion the gasket member having an annular intermediate portion and a cushioning portion formed between the intermediate portion and the outer peripheral portion to allow the outer peripheral portion to be elastically deformable with respect to the intermediate portion;
A method of manufacturing a gasket member, comprising: forming a low water absorption layer with a cured resin on the flat surface of the intermediate portion of the gasket member.

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