JP2017154760A - Seal bar, seal bar system, and method of manufacturing bag-like article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal bar to which the adhesion of a molten sealant layer squeezed out from an exterior body is suppressed.SOLUTION: Provided is a seal bar 30 in which a sealant layer 16a laminated on each of a pair of sheet materials 16 of an exterior body is fused together by heating and compressing marginal portions of the paired sheet materials, in which seal bar, the sheet material is formed such that a length L1 in a direction X along a main surface 16f of the marginal portion of the sheet material is equal to or smaller than a length L2 in a direction along a main surface of a marginal portion of the exterior body, and which comprises: a first compression surface 31a for compressing the marginal portion of the exterior body; and a recess 32 extending from the first compression surface and stepped back from the first compression surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a seal bar, a seal bar system, and a bag manufacturing method.

  Conventionally, a secondary battery in which a positive electrode layer and a negative electrode layer are stacked via a separator and sealed in an outer package, and each tab terminal of the positive electrode layer and the negative electrode layer is protruded from a heat seal portion of the outer package is known. . For example, a capacitor module disclosed in Patent Document 1 is known as a bag-like object formed by a bag-like exterior body such as this secondary battery.

  In this capacitor module, a power storage body (contained object) is enclosed in an exterior body in which a first film (sheet material) and a second film (sheet material) are heat-sealed around, and the tab terminals are heat-sealed upward. It protrudes from the part.

JP 2012-175084 A

In general, each film has a sealant layer such as a modified PP (polypropylene) layer that melts when heated in the inner layer. For example, the sealant layers of the respective films formed in a rectangular shape are overlapped in a contact state. The three edge portions of both the stacked films are sandwiched between the first seal bar and the second seal bar and heated and pressurized (heat sealed). As a result, the sealant layer melts and the sealant layers are welded together to form a heat seal portion. The exterior body is formed in a bag shape in which three edges are heat-sealed and one edge is opened.
An electrolyte or the like is filled into the exterior body from the opened edge of the exterior body. It is manufactured by heat-sealing this one edge of the exterior body.

  However, when the edge of the exterior body is heat-sealed, the melted sealant layer protrudes from the side surface of the exterior body. When this protrusion sticks to the seal bar, it carbonizes on the seal bar. For this reason, the seal bar becomes dirty due to carbonization of the material forming the sealant layer, and when the bag-like product is subsequently manufactured with this seal bar, there is a problem that the carbonized foreign matter adheres to or mixes in the bag-like product. is there.

  The present invention has been made in view of such problems, and includes a seal bar, a seal bar system, and a bag-like manufacturing method that suppresses adhesion of a melted sealant layer protruding from an exterior body. The purpose is to provide.

In order to solve the above problems, the present invention proposes the following means.
The seal bar of the present invention is the seal bar in which the sealant layers stacked on the respective sheet materials are welded to each other by heating and pressurizing the edges of the pair of sheet materials of the exterior body. A first pressure surface that is formed so that a length in a direction along the main surface of the material is equal to or less than a length in a direction along the main surface of the edge of the exterior body, and pressurizes the edge of the exterior body; And a concave portion formed so as to be continuous with the first pressure surface and recessed from the first pressure surface.

  Moreover, the bag-like product manufacturing method of the present invention is a bag in which an article to be contained is accommodated in the exterior body by applying pressure while heating the edges of the pair of sheet materials using the seal bar described above. A manufacturing method of a bag-like product for manufacturing a shaped product, wherein the first pressurizing surface of the seal bar is disposed on an edge portion of the pair of sheet materials, and the first pressurizing surface extends from the edge portion along the main surface. The pressurizing surfaces of the sheet material are brought into contact with each other so as not to protrude, and the edge portions of the pair of sheet materials are heated with the first pressurizing surface to heat the sealant layers of the respective sheet materials to each other. It is said.

  According to these inventions, the first pressure surface of the seal bar is brought into contact with the edges of the pair of sheet materials so that the first pressure surface does not protrude from the edge of the sheet material in the direction along the main surface. The melted sealant layer protrudes from the side surface of the exterior body, but a recess is formed around the protruded sealant layer.

  Moreover, the seal bar system of the present invention is a seal bar system comprising the seal bar described above and an auxiliary seal bar, wherein the seal bar protrudes from the first pressure surface. The auxiliary seal bar includes a convex portion, and the auxiliary pressure bar protrudes from the second pressure surface and a second pressure surface that pressurizes the edges of the pair of sheet materials together with the first pressure surface. A second convex portion, and when the first convex portion and the second convex portion are in contact, a gap is formed between the first pressure surface and the second pressure surface. It is characterized by being.

  Further, in the bag-like material manufacturing method of the present invention, the object to be accommodated is accommodated in the exterior body by applying pressure while heating the edges of the pair of sheet materials using the seal bar system described above. A bag-like product manufacturing method for manufacturing a bag-like product, wherein the first pressurizing surface of the seal bar and the second pressurizing surface of the auxiliary seal bar are provided at the edge of the pair of sheet materials, The first pressurization surface and the second pressurization surface are brought into contact with each other so as not to protrude from the edge portion in a direction along the main surface while sandwiching the edge portions of the pair of sheet materials, The sealant layer of each of the sheet materials is brought into contact with the second convex portion and pressed while heating the edges of the pair of sheet materials with the first pressure surface and the second pressure surface. It is characterized by welding them together.

  According to these inventions, a constant gap is formed between the first pressure surface and the second pressure surface when the first convex portion and the second convex portion are brought into contact with each other. For this reason, the thickness of the heat seal part heat-sealed in the edge part of an exterior body can be made constant.

  According to the seal bar, the seal bar system, and the bag-like product manufacturing method of the present invention, it is possible to suppress adhesion of the melted sealant layer protruding from the exterior body.

It is a top view which shows typically the principal part of the secondary battery of one Embodiment of this invention. It is sectional drawing of the side which shows typically the heat seal part of the secondary battery. It is sectional drawing explaining the manufacturing method of the secondary battery of one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the secondary battery.

Hereinafter, an embodiment of a seal bar (heat bar) according to the present invention will be described with reference to FIGS. 1 to 4 in the case where the bag-like material is a secondary battery.
FIG.1 and FIG.2 is a figure which shows an example of the secondary battery 10 manufactured with the seal bar of this embodiment. The secondary battery 10 is, for example, a lithium ion secondary battery, and is configured by placing an object 18 between a pair of sheet materials 16 of an exterior body 15 having a pair of sheet materials 16.

The configuration of the sheet material 16 is not particularly limited as long as the sealant layer 16a that melts when heated is the innermost layer. In this example, the sheet material 16 is configured by laminating a sealant layer 16a, an aluminum layer 16b, a nylon layer 16c, and a PET (polyethylene terephthalate) layer 16d in this order from the innermost layer.
The sealant layer 16a is made of, for example, a modified PP gradient material. The inner part of the sealant layer 16a can be firmly welded (thermally welded) to a sealant film 21 described later. The outer portion of the sealant layer 16a can be firmly welded to the aluminum layer 16b.

The sealant layer 16a has a lower melting point than the aluminum layer 16b, the nylon layer 16c, and the PET layer 16d. A thickness t1 of a sealant layer 16a of a heat seal portion 16e described later formed on the edge of the sheet material 16 is, for example, about 55 μm (micrometer), and a thickness t2 of the sheet material 16 constituting the heat seal portion 16e. Is, for example, about 125 μm.
A metal film layer may be provided between the sealant layer 16a and the aluminum layer 16b. A metal coating layer or an adhesive layer may be provided between the aluminum layer 16b and the nylon layer 16c.
The sheet material 16 as a whole is formed in a rectangular sheet shape in plan view. The pair of sheet materials 16 are stacked in the thickness direction.
The pair of sheet materials 16 are bonded to each other by welding the edge of the sealant layer 16a of one sheet material 16 and the edge of the sealant layer 16a of the other sheet material 16 of the pair of sheet materials 16. It is joined. A heat seal portion 16e is formed at a portion where the edge portion of the sheet material 16 is heat-welded, and the thickness is thinner than before the heat seal. The edge part of a pair of sheet material 16 and the edge part of the exterior body 15 have the same meaning.
The main surface 16f of the sheet material 16 means a main surface that is an outer surface of the sealant layer 16a and a main surface that is an outer surface of the PET layer 16d. The direction X along the main surface 16f of the sheet material 16 is one of two types of directions along the edge of the sheet material 16, for example.

  Although not shown in detail, the object 18 includes a power storage unit 19 in which positive electrode layers and negative electrode layers are alternately stacked via separators, and an electrolyte filled in the outer package 15. . For the positive electrode layer, for example, a main surface such as an aluminum foil provided with a positive electrode active material layer can be used. As the negative electrode layer, for example, a main surface such as a copper foil provided with a negative electrode active material layer can be used. The material which comprises a separator is not specifically limited. For example, a porous polymer film, a nonwoven fabric, a glass fiber, etc. can be mentioned.

The electrolyte is not particularly limited, and for example, a known electrolyte solution used in a known lithium ion secondary battery can be applied. Examples of the electrolytic solution include a mixed solution in which an electrolyte salt is dissolved in an organic solvent.
As the organic solvent, those having resistance against high voltage are preferable, for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, γ-butyrolactone, sulfolane, dimethyl sulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, 1,2-dimethoxyethane, Examples include polar solvents such as 1,2-diethoxyethane, tetrohydrafuran, 2-methyltetrahydrofuran, dioxolane, and methyl acetate, or a mixture of two or more of these solvents.
Examples of the electrolyte salt include LiClO ₄ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₆ , LiCF ₃ CO ₂ , LiPF ₆ SO ₃ , LiN (SO ₃ CF ₃ ) ₂ , Li (SO ₂ CF ₂ CF ₃ ) _2. , LiN (COCF ₃ ) ₂ , and a salt containing lithium such as LiN (COCF ₂ CF ₃ ) ₂ , or a mixture of two or more of these salts.

The first end of the tab terminal 20 is connected to each of the positive electrode layer and the negative electrode layer. The tab terminal 20 shown in FIG. 1 is a tab terminal for positive electrode layers, for example. The tab terminal 20 is formed of a conductive material such as metal, for example, in a plate shape having a thickness of about 0.5 mm.
A sealant film 21 is attached to the outer surface of the intermediate portion in the longitudinal direction of the tab terminal 20. The sealant film 21 is formed of the same material as that of the sealant layer 16a. The sealant film 21 is welded to the sealant layer 16a.
A second end portion of the tab terminal 20 protrudes from the heat seal portion 16 e of the sheet material 16 to the outside.

Next, a method for manufacturing the secondary battery 10 of the present embodiment for manufacturing the secondary battery 10 configured as described above (hereinafter simply referred to as a manufacturing method) will be described.
First, the seal bar system used in this manufacturing method will be described.
As shown in FIG. 3, the seal bar system 1 includes a first seal bar (seal bar) 30 and a second seal bar (auxiliary seal bar) 40.

The first seal bar 30 is formed so as to be connected to the first main body 31 formed in a rectangular parallelepiped shape and the first pressurization surface 31a which is the outer surface of the first main body 31, and is more than the first pressurization surface 31a. The first groove 31 (recessed portion) 32 recessed in the first side Z1 in the thickness direction Z of the first main body 31 and the second side Z2 in the thickness direction Z protruded from the first pressure surface 31a. And a first convex portion 33.
The first pressure surface 31a is formed, for example, in a rectangular shape and flat. The length L1 in the direction X along the main surface 16f of the first pressure surface 31a is formed to be equal to or less than the length L2 in the direction X along the main surface 16f of the edge of the exterior body 15. The first pressing surface 31 a is for pressing the edge of the outer package 15.

A pair of first groove portions 32 are formed so as to sandwich the first pressure surface 31a. In this example, the cross-sectional shape of the first groove portion 32 is a rectangular shape, but the cross-sectional shape is not particularly limited. This cross-sectional shape may be, for example, a semicircular shape or a triangular shape.
A pair of first convex portions 33 are formed so as to sandwich the pair of first groove portions 32.
The first main body 31, the pair of first groove portions 32, and the pair of first convex portions 33 are integrally formed of a material having a high thermal conductivity such as aluminum.

The second seal bar 40 has the same configuration as the first seal bar 30. That is, the second seal bar 40 is formed so as to be connected to the second main body 41 formed in a rectangular parallelepiped shape and the second pressurization surface 41a which is the outer surface of the second main body 41, and the second pressurization surface 41a. A second groove 42 that is recessed on the second side Z2 in the thickness direction Z, and a second protrusion 43 that protrudes on the first side Z1 in the thickness direction Z from the second pressure surface 41a. ,have.
The second pressure surface 41a is, for example, rectangular and flat. The length L3 in the direction X along the main surface 16f of the second pressure surface 41a is formed to be equal to or less than the length L2 in the direction X along the main surface 16f of the edge of the exterior body 15. The second pressure surface 41a is for applying pressure so as to sandwich the edge portions of the pair of sheet materials 16 together with the first pressure surface 31a.

A pair of second groove portions 42 are formed so as to sandwich the second pressure surface 41a. In this example, the cross-sectional shape of the second groove portion 42 is a rectangular shape, but the cross-sectional shape is not particularly limited. This cross-sectional shape may be, for example, a semicircular shape or a triangular shape.
A pair of second convex portions 43 are formed so as to sandwich the pair of second groove portions 42.
The second main body 41, the pair of second groove portions 42, and the pair of second convex portions 43 are integrally formed of the same material as the first seal bar 30.

Next, this manufacturing method will be specifically described. Below, it demonstrates focusing on welding of a pair of sheet material 16. FIG. First, the case where the three edges of the pair of sheet materials 16 are heat-sealed at once will be described, and then the case where the remaining one edge of the pair of sheet materials 16 is heat-sealed will be described.
Initially, the case where the three edge parts of a pair of sheet material 16 are heat-sealed at once is demonstrated. In this case, for example, the pair of sheet materials 16 are arranged substantially parallel to the horizontal plane. The seal bars 30 and 40 are arranged such that the pressing surfaces 31a and 41a face each other, the first side Z1 in the thickness direction Z is downward, and the second side Z2 in the thickness direction Z is upward. The

First, the first pressurization surface 31a of the first seal bar 30 and the second pressurization surface 41a of the second seal bar 40 are brought into contact with the edges of the pair of sheet materials 16 (sheet material arrangement step). At this time, it arrange | positions so that the 1st pressurization surface 31a and the 2nd pressurization surface 41a may pinch | edge the edge part of a pair of sheet material 16. FIG. Furthermore, it arrange | positions so that the 1st pressurization surface 31a and the 2nd pressurization surface 41a may not protrude from the edge part of the sheet | seat material 16 in the direction X along the main surface 16f.
The thickness t3 of the sealant layer 16a before heat sealing is about 80 μm, for example, and the thickness t4 of the sheet material 16 is about 150 μm, for example.
A power storage unit 19 or the like is disposed between the pair of sheet materials 16. Each tab terminal 20 protrudes outward from the edge of the sheet material 16 to be heat sealed.
When heat-sealing a plurality of edge portions of the pair of sheet materials 16 at a time, the first groove portion 32 and the first convex portion 33 of the first seal bar 30 are formed on the sheet material 16 as shown in FIG. It is preferable to form in a shape corresponding to a plurality of edges. The same applies to the second seal bar 40.

Next, as shown in FIG. 4, the first convex portion 33 and the second convex portion 43 are brought into contact with each other in the thickness direction Z, and a pair of sheets is formed by the first pressure surface 31a and the second pressure surface 41a. By applying pressure while heating the edge of the material 16, the sealant layers 16a of the respective sheet materials 16 are welded together (sheet material welding step).
At this time, a constant gap S is formed between the first pressure surface 31a and the second pressure surface 41a. The distance L4 between the first pressure surface 31a and the second pressure surface 41a is, for example, about 250 μm, which is twice the thickness t2 described above. Known heating means such as a heater is used for heating by the seal bars 30 and 40, and known pressurizing means such as a hydraulic cylinder and an air cylinder is used for pressurization by the seal bars 30 and 40. By heat-sealing the edges of the pair of sheet materials 16, the total thickness of the pair of sheet materials 16 is reduced by about 50 μm from about 300 μm to about 250 μm.

The sealant layers 16a at the edges of the pair of sheet materials 16 are melted in contact with each other, and the sealant layers 16a are welded together. The molten resin 16 a 1 that is the melted sealant layer 16 a protrudes from the side surface of the outer package 15. The molten resin 16a1 is affected by gravity and protrudes toward the first side Z1 in the thickness direction Z which is mainly downward. By forming the first groove portion 32 of the first seal bar 30 and the second groove portion 42 of the second seal bar 40 around the protruding molten resin 16a1, the molten resin is formed on the seal bars 30, 40. 16a1 hardly adheres.
Through the above steps, the three edges of the pair of sheet materials 16 are heat-sealed at a time.

Since the molten resin 16a1 mainly protrudes toward the first side Z1 in the thickness direction Z, a conventional seal bar in which the second groove portion 42 is not formed is used instead of the second seal bar 40. Also good.
In this case, the secondary battery 10 is manufactured using the first seal bar 30 of the present embodiment and the conventional seal bar.

Next, the exterior body 15 is disposed so that the edge of the exterior body 15 that has not yet been heat-sealed faces upward, and the exterior body 15 is filled with an electrolyte or the like. Next, the remaining one edge of the pair of sheet materials 16 is heat-sealed.
Here, the sheet material arranging step and the sheet material welding step described above are performed. In this case, since the direction in which the outer package 15 is arranged is changed, the thickness direction Z is a direction along the horizontal plane. For this reason, in the sheet material welding step, as shown as a shape P in FIG. 4, the molten resin 16a1 protrudes almost evenly on the first side Z1 and the second side Z2 in the thickness direction Z.
Even in this case, since the groove portions 32 and 42 are formed in the seal bars 30 and 40, the molten resin 16a1 hardly adheres to the seal bars 30 and 40.
Through the above steps, the secondary battery 10 in which the object 18 is accommodated in the exterior body 15 using the seal bar system 1 is manufactured.

As described above, according to the seal bar system 1 and the manufacturing method of the present embodiment, the pressing surfaces 31 a and 41 a of the seal bars 30 and 40 are connected to the edges of the pair of sheet materials 16 from the edges of the sheet material 16. The pressing surfaces 31a and 41a are brought into contact with each other in the direction X along the main surface 16f so as not to protrude. The molten resin 16a1, which is the melted sealant layer 16a, protrudes from the side surface of the exterior body 15, but grooves 32 and 42 are formed around the protruding molten resin 16a1.
Therefore, adhesion of the molten resin 16a1 protruding from the exterior body 15 to the seal bars 30, 40 can be suppressed.

  Since the first seal bar 30 includes the first convex portion 33 and the second seal bar 40 includes the second convex portion 43, the first convex portion 33 and the second convex portion 43 are brought into contact with each other. When this is done, a certain gap S is formed between the first pressure surface 31a and the second pressure surface 41a. For this reason, the thickness of the heat seal part heat-sealed in the edge part of the exterior body 15 can be made constant.

As mentioned above, although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications, combinations, and deletions within a scope that does not depart from the gist of the present invention. Etc. are also included. Furthermore, it goes without saying that the configurations shown in the embodiments can be used in appropriate combinations.
For example, in the said embodiment, you may comprise so that the 1st seal bar 30 may not be provided with the 1st convex part 33. FIG. Even in this configuration, if the first seal bar 30 includes the first groove portion 32, it is possible to prevent the molten resin 16a1 protruding from the exterior body 15 from adhering to the first seal bar 30. Because.
Similarly, the second seal bar 40 may be configured not to include the second groove portion 42 and the second convex portion 43.

In the first seal bar 30, the first groove 32 may be formed only on one side of the first pressure surface 31a.
In the embodiment, the bag is a secondary battery, but the bag is not limited to this, and may be a secondary battery other than a lithium ion secondary battery, a capacitor module, or the like.

1 Seal bar system 10 Secondary battery (bag-like)
DESCRIPTION OF SYMBOLS 15 Exterior body 16 Sheet material 16a Sealant layer 16f Main surface 18 Containment 30 First seal bar (seal bar)
31a First pressure surface 32 First groove (concave portion)
33 1st convex part 40 2nd seal bar (auxiliary seal bar)
41a 2nd pressurization surface 43 2nd convex part L1, L2, L3 Length S Clearance X The direction along a main surface

Claims (4)

In the seal bar that welds the sealant layers laminated to each of the sheet materials by heating and pressurizing the edges of the pair of sheet materials of the exterior body,
The first sheet is formed so that the length in the direction along the main surface of the sheet material is equal to or less than the length in the direction along the main surface of the edge of the exterior body, and pressurizes the edge of the exterior body. A pressing surface of
A recess formed to be continuous with the first pressure surface and recessed from the first pressure surface;
A seal bar comprising: A seal bar system comprising the seal bar according to claim 1 and an auxiliary seal bar,
The seal bar includes a first protrusion protruding from the first pressure surface,
The auxiliary seal bar is
A second pressure surface that pressurizes the edges of the pair of sheet materials together with the first pressure surface;
A second protrusion protruding from the second pressure surface;
With
A seal bar system, wherein a gap is formed between the first pressure surface and the second pressure surface when the first convex portion and the second convex portion are in contact with each other. . A manufacturing method of a bag-like product for manufacturing a bag-like product in which an object to be contained is accommodated in the exterior body by applying pressure while heating edges of the pair of sheet materials using the seal bar according to claim 1. Because
Bringing the first pressure surface of the seal bar into contact with the edges of the pair of sheet materials so that the first pressure surface does not protrude from the edge in a direction along the main surface;
A method for manufacturing a bag-like material, wherein the sealant layers of the respective sheet materials are welded to each other by applying pressure while heating the edges of the pair of sheet materials on the first pressure surface. A bag-like article for producing a bag-like article in which the article to be contained is accommodated in the exterior body by heating and pressurizing edges of the pair of sheet materials using the seal bar system according to claim 2. A manufacturing method comprising:
The first pressure surface of the seal bar and the second pressure surface of the auxiliary seal bar are sandwiched between the edge portions of the pair of sheet materials and the main portion from the edge portions. Contacting the first pressure surface and the second pressure surface so as not to protrude in a direction along the surface,
Contacting the first convex portion and the second convex portion;
A bag shape characterized in that the sealant layers of the respective sheet materials are welded to each other by applying pressure while heating the edges of the pair of sheet materials on the first pressure surface and the second pressure surface. Manufacturing method.

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