JPH076744A - Film pack battery and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a film pack battery in which bonding strength in a bonding part between an electrode plate and a film pack container is high and an adhesive layer forming the bonding part does not break easily. CONSTITUTION:A first adhesive with high adhesion to a film pack container is applied to release paper and dried to form an adhesive body. The first adhesive contains a thermoplastic resin which softens the cured first adhesive. A second adhesive with high adhesion to an electrode plate 2 is applied to an objective bonding part 2a of the electrode plate 2. The adhesive body is placed on the second adhesive to form an adhesive stacked layer. The adhesive stacked layer is heated to a temperature at which the first adhesive is melted and the second adhesive is cured, and cooled. The cured first adhesive and part of the film pack container are piled and bonded by hot-melt bonding. A soft bonding layer 5 into which the first adhesive and the second adhesive diffuse is formed between a first adhesive layer 3 and a second adhesive layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film pack type battery and a manufacturing method thereof.

[0002]

2. Description of the Related Art A film pack type battery is one in which an output terminal is directly drawn from a film pack battery case made of a sheet-shaped or film-shaped synthetic resin, or one side of a collector of a polar plate is inside the battery case. There are things that are joined to the wall. In any of these cases, a part of the electrode plate is bonded to the film pack battery case through a bonding structure. In the initially used joining structure or joining method, an adhesive layer was formed on the portion to be joined of the electrode plate using an adhesive containing a thermoplastic resin material capable of being heat-welded, and this adhesive layer was formed into a film pack battery case. It is heat-welded to. However, an adhesive showing a high bondability to the film pack battery does not show a very high bondability to the electrode plate. Therefore, when the size of the battery case changes due to charge / discharge, a force may be applied to the joint portion, and the electrode plate and the adhesive layer may be separated from each other. In particular, when acid mist is generated in the battery case due to charging or heat is generated in the electrode plate, the progress of peeling is accelerated. Therefore, as shown in the schematic view of FIG. 9, a first adhesive layer 103 including a thermoplastic synthetic resin material having high bonding properties with respect to the synthetic resin body forming the film pack battery case 101.
And a second adhesive layer 104 containing a resin material having a high bonding property to the electrode plate 102 are laminated to form a part 101a of the film pack battery case 101 and a bonded portion 102a of the electrode plate 102. A film pack type battery for joining and has been proposed. In order to bond the electrode plate 102 and the film pack battery case 101 with such a joint structure, first, the electrode plate 10
After the second adhesive is applied on the second to-be-joined portion 102a and then the second adhesive is heat-cured to form the second adhesive layer 104, the first adhesive is formed on the second adhesive layer 104. After applying the adhesive, the adhesive is dried to form the first adhesive layer 103. Then, the first adhesive layer 103 and the film pack battery case 101 are overlapped with each other and joined by heat welding.

[0003]

However, when the electrode plate and the film pack battery case are bonded to each other by such a joint structure, the difference in the adhesiveness between the two adhesive layers, the thickness balance, or the glass effect due to the heat influence. Peeling occurs at the bonding interface K between the first adhesive layer 103 and the second adhesive layer 104 due to a difference in transition temperature (a temperature at which a hard solid transitions to a soft rubber state), a difference in expansion coefficient and a contraction coefficient, and the like. The problem arises.

An object of the present invention is to provide a film pack type battery having a high bonding strength between the electrode plate and the film pack battery case, and a method for producing the film pack type battery.

Another object of the present invention is a film pack which has a high bonding strength between the electrode plate and the film pack battery case, and which is unlikely to cause cracks in the adhesive layer forming the bonding portion between the electrode plate and the film pack battery case. Type battery and a method of manufacturing the film pack type battery.

[0006]

According to a first aspect of the invention, a part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate are made of an adhesive. Bonded by the bonding structure used, and the bonding structure exhibits high bonding properties to the synthetic resin body, and exhibits high bonding properties to the bonded portion of the first adhesive layer and the electrode plate containing the thermoplastic synthetic resin material. As an object of improvement, a film pack type battery that is configured by stacking a second adhesive layer containing a resin material,
A bonding layer in which the resin materials contained in both the adhesive layers are mutually diffused is formed at the polymerized portion of the first adhesive layer and the second adhesive layer. In this joining layer, it is not necessary that the resin material of the first adhesive and the resin material of the second adhesive be uniformly diffused, and the resin material of the first adhesive and the resin material of the second adhesive are not necessarily dispersed. The diffusion rate with the material may be biased.

According to the second aspect of the invention, a softening material for softening the bonding layer is used as the thermoplastic synthetic resin material contained in the first adhesive layer. The softening referred to here is to lower the elastic force of the bonding layer to facilitate absorption of external force.

In the third aspect of the invention, a third adhesive layer softer than the first and second adhesive layers is provided between the first adhesive layer and the second adhesive layer. Then, a first bonding layer, in which the materials contained in both adhesive layers are mutually diffused, is formed in the polymerized portion of the first adhesive layer and the third adhesive layer, and the first adhesive layer and the second adhesive layer are formed. A third bonding layer in which the materials contained in both adhesive layers diffuse into each other is formed in a portion where the adhesive layer of No. 3 and the adhesive layer overlap. The first and second bonding layers may be formed so that the bonding layers are adjacent to each other, or the bonding layers may be overlapped with each other.

According to the fourth aspect of the invention, a part of the film pack battery case formed by using the sheet-shaped or film-shaped synthetic resin body and the joined portion of the electrode plate are bonded to the synthetic resin body. A film pack formed by joining using a first adhesive containing a thermoplastic synthetic resin material showing the above and a second adhesive containing a thermosetting resin material showing a high joining property to a joined portion of an electrode plate. A method of manufacturing a rechargeable battery is targeted for improvement. In the present invention, first, the first adhesive whose melting temperature is lower than the curing temperature of the second adhesive is used. Then, a sheet-shaped or film-shaped adhesive body is formed using the first adhesive, and the adhesive body is overlaid on the portion to be joined of the electrode plate via the second adhesive to form an adhesive polymer layer. Next, the adhesive polymerization layer is heated to a temperature at which the first adhesive melts and the second adhesive hardens to cure the second adhesive, and then the adhesive polymerization layer is cooled to cool the first adhesive. The adhesive of No. 1 is cured. After that, the cured first adhesive and a part of the film pack battery case are overlapped with each other and joined by heat welding. The adhesive polymerization layer may be cooled by either forced cooling or natural cooling.

According to the fifth aspect of the present invention, a thermoplastic synthetic resin material is used which softens the hardened first adhesive when diffused into the first adhesive.

In the invention of claim 4, an adhesive containing a thermosetting resin material is used as the second adhesive, but the second adhesive is made of a thermoplastic synthetic resin material like the first adhesive. Adhesives that include can be used. The invention of claim 6 is directed to a method of manufacturing a film pack type battery by using a second adhesive containing a thermoplastic resin material having a high bonding property to a bonded portion of an electrode plate. In the present invention, a sheet-shaped or film-shaped first adhesive body is made using the first adhesive,
A sheet-like or film-like second using a second adhesive.
The adhesive body is prepared, and the first adhesive body is overlaid on the portion to be joined of the electrode plate through the second adhesive body to form the adhesive polymerization layer. Then, after heating the adhesive polymerization layer to a temperature at which the first adhesive and the second adhesive are melted, the adhesive polymerization layer is cooled to cure the first and second adhesives. Then cured first
The adhesive and the part of the film pack battery case are superposed on each other and joined by heat welding.

According to a seventh aspect of the invention, there is provided a third adhesive containing a thermoplastic synthetic resin material having a melting temperature lower than the curing temperature of the second adhesive and softer than the first and second adhesives. A sheet-shaped or film-shaped adhesive is prepared by using the adhesive, and the adhesive is superposed on the bonded portion of the electrode plate via the second adhesive to form an adhesive polymer layer. Then, the adhesive polymerization layer is heated to a temperature at which the third adhesive melts and the second adhesive hardens. Then, the adhesive polymerization layer is cooled to cure the third adhesive. Then, the cured third adhesive and the layer of the first adhesive formed on the surface of a part of the film pack battery case are superposed on each other and joined by heat welding.

[0013]

According to the first aspect of the present invention, when the bonding layer in which the resin materials contained in both the adhesive layers are mutually diffused is formed in the polymerized portion of the first adhesive layer and the second adhesive layer, Since this bonding layer does not form a clear interface between the first adhesive layer and the second adhesive layer, there is a difference between the first adhesive layer and the second adhesive layer as in the conventional case. It is possible to prevent peeling.

When the softening material for softening the joining layer is used as the thermoplastic synthetic resin material contained in the first adhesive layer as in the second aspect of the invention, even if an external force is applied to the joining layer. The bonding layer can be deformed to absorb external force. Therefore, it is possible to prevent the joint layer from being damaged even if the joint portion between the electrode plate and the film pack battery case is bent or an impact is applied to the joint portion.

According to the third aspect of the invention, a third adhesive layer softer than the first and second adhesive layers is provided between the first adhesive layer and the second adhesive layer, It prevents the polymerized portion of the first adhesive layer and the second adhesive layer from being damaged by an external force. In addition, the materials contained in each adhesive layer are mutually diffused in the polymerized portion between the first adhesive layer and the third adhesive layer and the polymerized portion between the second adhesive layer and the third adhesive layer. Since each of the bonding layers is formed, a clear interface is not formed between the adhesive layers. Therefore, it is possible to prevent peeling between the adhesive layers as in the conventional case.

In the method of the fourth aspect of the present invention, in the process of heating and curing the second adhesive, the first adhesive melts and the resin materials of the first adhesive and the second adhesive oppose each other. Diffuse gradually into the adhesive. Then, after heating and cooling to cure the melted first adhesive, a resin is provided between the first adhesive layer and the second adhesive layer from one layer toward the other layer. A bonding layer is formed in which the concentration of the material gradually changes. Since the first adhesive layer has thermoplasticity, the synthetic resin body of the film pack battery case can be heat-welded onto the first adhesive layer. Therefore, according to the present invention, the first
A bonding layer in which the resin materials of both layers are diffused can be easily formed between the adhesive layer and the second adhesive layer. Further, in the present invention, if the first adhesive body is prepared in advance, there is an advantage that the time for drying the first adhesive agent by the conventional manufacturing method can be shortened.

According to a fifth aspect of the present invention, the first synthetic resin material, which is hardened when diffusing into the first adhesive, is used.
If a softening agent is used, the joining layer formed between the first adhesive layer and the second adhesive layer is softened,
It is possible to form a bonding layer that is less likely to be damaged even when external force is applied.

When the thermoplastic synthetic resin is applied using a hot melt coater, it can be applied in a shorter time than the thermosetting synthetic resin. Therefore, when an adhesive containing a thermoplastic synthetic resin material is used as the second adhesive as in the invention of claim 6, the adhesive polymerization layer can be formed in a short time, and the adhesive polymerization layer does not need to be thermoset. . Therefore, the productivity of the film pack type battery can be improved.

In the method of the seventh aspect of the present invention, in the process of heating and curing the second adhesive, the third adhesive melts and the resin materials of the third adhesive and the second adhesive are in opposition to each other. Diffuse gradually into the adhesive. Then, after heating and cooling to cure the melted third adhesive, a resin is provided between the third adhesive layer and the second adhesive layer from one layer toward the other layer. A second bonding layer is formed in which the material concentration gradually changes. When the third adhesive layer is heat-welded to the first adhesive layer formed on a part of the surface of the film pack battery case, the third adhesive and the resin material of the first adhesive are opposed to each other. Diffuse gradually into the adhesive. And the third
Between the first adhesive layer and the second adhesive layer, the concentration of the resin material gradually changes from one layer to the other layer.
A bonding layer is formed. Therefore, according to the present invention, the first and second bonding layers in which the soft third adhesive is diffused can be easily formed.

[0020]

Embodiments of the present invention applied to a film pack type lead battery will be described in detail below with reference to the drawings. (Embodiment 1) FIG. 1 is a diagram schematically showing a joint structure between an electrode plate terminal and a film pack battery case of one embodiment in which the present invention is applied to a film pack type lead battery. In FIG. 1, 1
Is a film pack battery case, 2 is an electrode plate terminal, 3
Is a first adhesive layer, 4 is a second adhesive layer,
Reference numeral 5 is a bonding layer. The film pack battery case 1 is formed of a laminated film, and the innermost layer 1a facing the electrode plate terminals 2 is formed of heat-weldable polypropylene. The electrode plate terminal 2 is formed integrally with an electrode plate current collector made of a lead sheet. The first adhesive layer 3 has a high bonding property to polypropylene forming the film pack battery case 1, and is formed of a thermoplastic synthetic resin material (chlorinated polypropylene) 3a that melts at the curing temperature of the epoxy resin 4a described later. Has been done. The second adhesive layer 4 is formed of a thermosetting resin material (epoxy resin) 4a having a high bondability with lead forming the electrode plate terminal 2. In addition, in this figure, in order to facilitate understanding of the diffusion state of the chlorinated polypropylene 3a and the epoxy resin 4a, each resin material is schematically represented by using circles and triangles. The bonding layer 5 is formed by mutually diffusing the chlorinated polypropylene 3a and the epoxy resin 4a. In this embodiment, the concentration of the chlorinated polypropylene 3a decreases from the film pack battery case 1 toward the electrode plate terminal 2. The chlorinated polypropylene 3a and the epoxy resin 4a are mutually diffused so that the concentration of the epoxy resin 4a becomes thinner from the electrode plate terminal 2 toward the film pack battery case 1. In this embodiment, the adhesive layer adheres the film pack battery case 1 and the electrode plate terminal 2 over a length of 10 mm, and the first adhesive layer 3, the second adhesive layer 4 and Bonding layer 5
Have thicknesses of 5 μm, 7 μm and 3 μm, respectively.

Next, a method of manufacturing the film pack type lead battery of this embodiment will be described.

First, a glassine paper coated with silicon and having a thickness of 70 μm and a heat-resistant release paper was coated on one side with a first adhesive in which 20% by weight of chlorinated polypropylene was dissolved in toluene and then dried to be chlorinated to a thickness of about 10 μm. A sheet-shaped adhesive body having a polypropylene layer was prepared. Next, a second adhesive made of epoxy resin is applied to the bonded portion 2a of the electrode plate terminal 2 to form an adhesive material layer having a thickness of 5 μm.
The above-mentioned adhesive was placed on the adhesive material layer so that the first adhesive and the adhesive material layer were bonded to each other to form an adhesive polymerization layer of the first adhesive and the second adhesive. . Next, the electrode plate was placed in a curing oven, and then the polymerized adhesive layer was heated at 120 ° C. for 10 minutes. When the heating starts, the first adhesive melts at about 90 ° C, and the second adhesive has a low viscosity and then gradually hardens,
The first adhesive and the second adhesive penetrate into each other's adhesive. After heating, the adhesive polymerization layer was cooled at room temperature, the release paper was peeled off, and the first adhesive layer and a part of the film pack battery case were overlapped and joined by heat welding.

When a film pack type battery is manufactured by using an adhesive containing a thermoplastic resin material as the second adhesive,
Acrylic resin with hot melt coater thickness 30
The adhesive material layer may be formed by applying it to a thickness of .mu.m, and the others may be manufactured by the same method as described above. Also in this case, as shown in FIG. 1, the concentration of chlorinated polypropylene decreases from the film pack battery case toward the electrode plate terminals, and the concentration of acrylic resin decreases from the electrode plate terminals toward the film pack battery case. A bonding layer is formed between the polymerized portion of the first adhesive layer and the second adhesive layer.

Next, in order to investigate the characteristics of the film pack type lead battery of this embodiment, three kinds of film pack type lead batteries a, b and c were prepared and tested. The film pack type lead battery a is a battery of the embodiment manufactured by using an adhesive made of a thermosetting resin material as the second adhesive, and the film pack type lead battery b is a thermoplastic resin as the second adhesive. A battery of an example manufactured by using an adhesive made of a material,
The film pack type lead battery c is a conventional battery having a joint structure shown in FIG. In the conventional battery c, the second adhesive used in Example a is applied on the bonded portion of the electrode plate terminal, and then the second adhesive is cured at 80 ° C. for 1 hour to form the second adhesive layer. After that, the first adhesive used in Example a was applied onto this second adhesive layer, and after drying, the first adhesive layer and the film pack battery case were superposed. Both were joined by heat welding and manufactured. The batteries a, b, and c all have the same structure except the junction structure. Then, the T-shaped peel strength between the film pack battery case of each battery and the bonded portion of the electrode plate terminal was measured. FIG. 2 shows the measurement result. It can be seen from FIG. 2 that the batteries a and b of the embodiment have higher T-shaped peel strength than the conventional battery c. This is because in the conventional battery c, both adhesive layers are separated at the interface between the first adhesive layer and the second adhesive layer.

Next, each battery was subjected to an overcharge test in which a charge of 2.45 V / cell was continued at 45 ° C. and 98% RH atmosphere, and the electrolytic solution crawled at the joint between the film pack battery case and the electrode plate terminal. I checked the rising condition. As the electrolytic solution, dilute sulfuric acid having a specific gravity of 1.300 was used for each battery. FIG. 3 shows the measurement result. As shown in FIG. 3, in the conventional battery c, the electrolytic solution crawling up to 10 mm in about 50 days and the electrolytic solution leaked from the battery case, whereas in the batteries a and b of the embodiment, 100 days passed. It can be seen that the electrolytic solution hardly crawls.

Next, the T-shaped peel strength of the adhesive layer of the battery a of the example with respect to the film pack battery case (polypropylene) and the electrode plate terminal (lead) was measured. FIG. 4 (A) shows the measurement results of the T-shaped peel strength of the adhesive layer with respect to the film pack battery (polypropylene), and FIG. 4 (B) shows the T-shaped peel of the adhesive layer with respect to the electrode plate terminals (lead). The measurement result of strength is shown. The T-shaped peel strengths of chlorinated polypropylene and epoxy resin are also shown in each figure. Figure 4
From (A), it can be seen that the adhesive layer of the battery a of Example has the same T-shaped peel strength as that of chlorinated polypropylene with respect to the film pack battery (polypropylene). See also FIG.
From (B), the adhesive layer of the battery “a” of the example is an electrode plate terminal (lead).
On the other hand, it can be seen that it has the same T-shaped peel strength as the epoxy resin.

Although an adhesive containing chlorinated polypropylene was used as the first adhesive in the above-mentioned examples, the first adhesive may be appropriately selected depending on the material of the film pack battery case, for example, polyester-based adhesive. Resin, polyethylene resin, EVA resin can be used. In particular, when a softening material such as polyethylene resin that softens the joining layer is used, it is possible to prevent the joining layer from being damaged by an external force. As the second adhesive, a polyurethane resin, a phenol resin, a polyamide resin, a polyimide resin, or the like can be used instead of the epoxy resin or the acrylic resin.

(Embodiment 2) FIG. 5 (A) is a sectional view of the joint between the electrode plate terminal and the film pack battery case of the present embodiment in which the present invention is applied to a film pack type lead battery. B)
FIG. 6 is a diagram schematically showing a cross section taken along the line BB of FIG. As shown in FIG. 5 (A), in the joint portion of the film pack type lead battery of the present embodiment, one half portion 11 and the other half portion 12 of the film pack battery case 10 are electrode plates with the adhesive layer 60 interposed therebetween. The terminals 20 are joined so as to be sandwiched in the thickness direction. As shown in FIG. 5 (B), the adhesive layer 60 includes a first adhesive layer 30, a first bonding layer 51, a second bonding layer 52, a second bonding layer 52, Two
The adhesive layer 40 is laminated and formed. The first adhesive layer 30 is formed of a thermoplastic synthetic resin material (chlorinated polypropylene) 30a having a high bondability with the polypropylene forming the film pack battery case 10.
The second adhesive layer 40 is a thermosetting resin material (epoxy resin) having a high bondability with lead forming the electrode terminal 20.
It is formed of 40a. Also in this figure, in order to facilitate understanding of the diffusion state of the resin material, each resin material is schematically represented by using geometrical marks.

The first bonding layer 51 is formed by diffusing the chlorinated polypropylene 30a and the softening material 50a into each other. In this embodiment, the film pack battery case 10 to the second layer are formed.
The concentration of the chlorinated polypropylene 30a becomes thinner toward the bonding layer 52 of the above, and the concentration of the softening material 50a becomes thinner toward the film pack battery case 10 from the second bonding layer 52 and the chlorinated polypropylene 30a becomes softer. The material 50a is mutually diffused. As the softening material 50a, a thermoplastic synthetic resin material that melts at the curing temperature of the epoxy resin 40a and is softer than the chlorinated polypropylene 30a and the epoxy resin 40a may be used. In this embodiment, a product manufactured by Asahi Kasei Co. The polyester resin sold under the name is used. The second bonding layer 52 is formed by mutually diffusing the epoxy resin 40a and the softening material 50a. In this embodiment, the concentration of the epoxy resin 40a from the electrode plate terminal 20 toward the first bonding layer 51 is increased. Thinning,
The epoxy resin 40a and the softening material 50a are mutually diffused so that the softening material 50a becomes thinner from the first bonding layer 51 toward the electrode terminal 20. In this embodiment, the first
The third adhesive layer is constituted by the bonding layer 51 and the second bonding layer 52. The combined thickness of the first bonding layer 51 and the second bonding layer 52 has a dimension of 0.05 to 0.3 mm.

Next, a method of manufacturing the film pack type lead battery of this embodiment will be described with reference to FIG.

First, as shown in FIG. 6 (A1), glass coated with silicon on a 70 μm-thick heat-resistant release paper G is coated on one side with a softening material of 50% by weight made of polyester resin dissolved in toluene. A third soft adhesive material 50a having a thickness of about 60 μm, which is dried by applying an adhesive.
A sheet-shaped adhesive body on which the adhesive material layer of 1 was formed.
Further, as shown in FIG. 6 (A2), a second adhesive composed of an epoxy resin 40a is applied to the bonded portion 20a formed on the outer periphery of the electrode plate terminal 20 to form a second adhesive material layer having a thickness of 100 μm. did. Next, as shown in FIG. 6B, the above-mentioned adhesive is placed on the second adhesive material layer so as to surround the electrode plate terminals 20 so that the third adhesive material layer and the second adhesive material layer are joined. It was placed on to prepare an adhesive polymerization layer. Next, the electrode plate was placed in a curing oven, and then the polymerized adhesive layer was heated at 120 ° C. for 10 minutes. When heating is started, the third adhesive melts at about 100 ° C., and the second adhesive lowers its viscosity and then gradually hardens,
The third adhesive and the second adhesive penetrate into each other's adhesive to form a second bonding layer 52 as shown in FIG. 6C. After heating, the adhesive polymerization layer was cooled at room temperature, and then the release paper G was released.

Next, the first adhesive prepared by dissolving 20% by weight of chlorinated polypropylene in toluene was used as a film pack battery case 1.
The first adhesive material layer made of chlorinated polypropylene having a thickness of about 5 .mu.m was formed by applying it on predetermined positions of the half portions 11 and 12 of 0 and then drying. Then, as shown in FIG. 6D, the half parts 11 and 12 of the film pack battery case 10 are arranged so as to sandwich the electrode plate terminal 20 in the thickness direction, and the third adhesive material layer and the chlorinated polypropylene 30a 1 of the adhesive material layers were laminated. Then, the half portions 11 and 12 of the film pack battery case 10 were overlapped with each other using a heat press and heated at 130 ° C. for 2 seconds. As a result, as shown in FIG. 6E, the first bonding layer in which the third adhesive (softening material) 50a and the first adhesive (chlorinated polypropylene) 30a penetrate into each other's adhesive. 51 was formed to complete the joint portion of the film pack type lead battery.

Next, in order to investigate the characteristics of the battery of this embodiment, a test was conducted using the battery of this embodiment and a conventional battery.
The conventional battery is the same conventional battery as that used in the test of Example 1, and has the junction structure shown in FIG. Then, each battery was set to 2.45 in an atmosphere of 45 ° C. and 98% RH.
An overcharge test in which the V / cell was continuously charged was performed to examine the state in which the electrolytic solution crawled up the joint between the film pack battery case and the electrode plate terminal. The electrolytic solution has a specific gravity of 1.3 for each battery.
00 diluted sulfuric acid was used. FIG. 7 shows the measurement result. From the figure, in the conventional battery, in about 60 days, the electrolytic solution reached 6 mm, and the electrolytic solution leaked from the battery case. You can see that it hardly crawls.

Next, each of the present embodiment and the conventional battery is divided into 5 parts.
Individually prepared, the joint portion between the electrode plate terminal of each battery and the film pack battery case was bent in the thickness direction of the electrode plate terminal, and the relationship between the bending angle and the cracking rate of the adhesive layer at the joint portion was investigated. FIG. 8 shows the measurement result. As shown in the figure, in the conventional battery, when the bending angle exceeds 60 °, most of the adhesive layers of the battery are cracked, whereas in the battery of the present embodiment, even if the bending angle exceeds 90 °, about 6%.
It can be seen that only 0% of the batteries have cracked adhesive layers.

Although the polyester resin is used as the softening material in the above embodiment, an ionomer resin, a urethane resin, or a silicone rubber can be used as the softening material.

In this embodiment, the first adhesive layer 51 and the second adhesive layer 52 constitute the third adhesive layer.
A layer of only the softening material 50a may be formed between the first bonding layer 51 and the second bonding layer 52, and the third adhesive layer may be composed of these three layers. Such a third
The adhesive layer can be formed by appropriately selecting conditions for heating the adhesive polymerized layer, heating for superimposing and heating each half of the film pack battery case, and the like.

In this embodiment, an adhesive containing chlorinated polypropylene was used as the first adhesive, and the innermost layer of the film pack battery case 1 facing the electrode plate terminals 2 was made of polypropylene. When the innermost layer of the tank is formed using a resin that can be used as the first adhesive, the innermost layer of the film pack battery case can be used as the first adhesive. In that case, if the third adhesive material layer and the innermost layer of the film pack battery case are joined and half of the film pack battery case is superposed and heated using a heat press, the third adhesive (softening The material) and the resin forming the innermost layer of the film pack battery case penetrate into each other to form the first bonding layer.

Next, preferred embodiments of the invention described in the present application will be shown.

[Embodiment 1] A part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate exhibit a bondability to the synthetic resin body. A film pack formed by joining using a first adhesive containing a thermoplastic synthetic resin material and a second adhesive containing a thermosetting resin material showing a high joining property to the joined portion of the electrode plate. A method of manufacturing a battery
An adhesive having a melting temperature lower than the curing temperature of the second adhesive is used as the adhesive, and the sheet-shaped or film-shaped adhesive is obtained by applying the first adhesive to heat-resistant release paper and then drying. The second plate on the bonded portion of the electrode plate.
The adhesive body is laminated via the adhesive of (1) to form an adhesive polymer layer, and the adhesive polymer layer is heated to a temperature at which the first adhesive melts and the second adhesive hardens. Second
After curing the adhesive, the adhesive polymerization layer is cooled to cure the first adhesive, the heat-resistant release paper is peeled from the cured first adhesive, and then the first adhesive is cured. A method for manufacturing a film pack type battery, characterized in that the adhesive and the part of the film pack battery case are overlapped and bonded by heat welding.

According to this embodiment, the heat-resistant release paper is first
A sheet-shaped or film-shaped adhesive can be formed by a simple operation by applying the adhesive and then drying.
If the release paper is peeled off after cooling,
The adhesive layer can be formed, and the subsequent heat welding can be reliably performed.

[Embodiment 2] One half and the other half of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body are arranged so as to sandwich an electrode plate terminal. A part of one half of the pack battery case and a part of the other half and the part to be joined on the outer periphery of the electrode plate terminal are joined by a joining structure using an adhesive, and the joining structure is the synthetic resin. A first adhesive layer containing a thermoplastic synthetic resin material having a high bondability to the body and a second adhesive layer containing a resin material having a high bondability to the portion to be joined of the electrode plate terminal; A film-pack type battery configured by stacking a plurality of layers, the third pack being softer than the first and second adhesive layers between the first adhesive layer and the second adhesive layer. An adhesive layer is provided, and the first adhesive layer and the third adhesive layer are overlapped with each other. A first bonding layer is formed in which materials contained in both adhesive layers are mutually diffused, and a material contained in both adhesive layers is formed at a polymerization portion of the second adhesive layer and the third adhesive layer. A film pack type battery in which a second bonding layer in which is diffused is formed.

[Embodiment 3] One half and the other half of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body are heat-welded to each other with an electrode plate terminal interposed therebetween. A first half containing a thermoplastic synthetic resin material exhibiting a bonding property with respect to the synthetic resin body in a part of the one half and a part of the other half and the part to be joined on the outer periphery of the electrode plate terminal; A method of manufacturing a film pack type battery by bonding with an adhesive and a second adhesive containing a thermosetting resin material showing high bonding property to the bonded portion of the electrode plate, respectively. , A third adhesive containing a thermoplastic synthetic resin material having a melting temperature lower than the curing temperature of the second adhesive and softer than the first and second adhesives was applied to the heat-resistant release paper. A sheet-like or film-like sheet on which a third adhesive material layer is formed by being dried later An adhesive body is formed, a second adhesive material layer made of the second adhesive is formed on the joined portion of the electrode plate terminal, and the second adhesive material layer and the third adhesive material layer are formed. Are bonded to each other and the adhesive body is arranged so as to surround the electrode plate terminal to form an adhesive polymerization layer, and the adhesive polymerization layer is melted by the third adhesive and cured by the second adhesive. And then the second adhesive is cured, the adhesive polymerized layer is cooled to cure the third adhesive, and then the heat-resistant release paper is peeled off. Forming a first adhesive material layer made of the first adhesive on a part of the one half and a part of the other half of the film pack battery case, and then sandwiching the electrode plate terminals. Arranging the one half and the other half of the film pack battery case, the third adhesive material layer and the third half A film pack type battery, characterized in that the adhesive material layer is laminated, and heat is applied while pressurizing so that the one half and the other half are overlapped, and the two are joined by heat welding. Manufacturing method.

[0043]

According to the first aspect of the present invention, a bonding layer in which the resin materials contained in both adhesive layers are mutually diffused is formed in the polymerized portion of the first adhesive layer and the second adhesive layer. Therefore, the bonding layer does not form a clear interface between the first adhesive layer and the second adhesive layer. Therefore, it is possible to prevent peeling from occurring between the first adhesive layer and the second adhesive layer as in the conventional case, and it is possible to prevent the peeling between the electrode plate and the film pack battery case. It is possible to obtain a high film pack type battery.

According to the invention of claim 2, since the softening material for softening the joining layer is used as the thermoplastic synthetic resin material contained in the first adhesive layer, the electrode plate and the film pack battery case are joined together. It is possible to prevent the joining layer from being damaged even if the portion is bent or an impact is applied to the joining portion.

According to the invention of claim 3, a third adhesive layer softer than the first and second adhesive layers is provided between the first adhesive layer and the second adhesive layer. Thereby, it is possible to prevent the polymerized portion of the first adhesive layer and the second adhesive layer from being damaged by an external force. Moreover, the polymerized portion of the first adhesive layer and the third adhesive layer and the second adhesive layer and the third adhesive layer
Since the bonding layer in which the materials contained in each adhesive layer diffuse into each other is formed in the overlapping portion with the adhesive layer of
No clear interface is formed between the adhesive layers. Therefore, it is possible to prevent peeling between the adhesive layers as in the conventional case.

According to the invention of claim 4, in the process of heating and curing the second adhesive, the first adhesive melts,
The resin materials of the first adhesive and the second adhesive gradually diffuse into each other's adhesive. Therefore, it is possible to easily form the joining layer in which the resin materials of both layers are diffused between the first adhesive layer and the second adhesive layer.

According to the invention of claim 5, as the thermoplastic synthetic resin material, the first cured material is obtained when it is dispersed in the first adhesive.
Since a softening agent is used, the bonding layer formed between the first adhesive layer and the second adhesive layer is softened to form a bonding layer that is not easily damaged even when external force is applied. can do.

According to the invention of claim 6, since an adhesive containing a thermoplastic synthetic resin material is used as the second adhesive,
The adhesive polymerized layer can be formed in a short time, and the adhesive polymerized layer does not need to be thermally cured, so that the productivity of the film pack type battery can be improved.

According to the invention of claim 7, in the process of heating and curing the second adhesive, the third adhesive melts,
The resin materials of the third adhesive and the second adhesive gradually diffuse into each other's adhesive. When the third adhesive layer is heat-welded to the first adhesive layer formed on a part of the surface of the film pack battery case, the third adhesive and the resin material of the first adhesive are opposed to each other. Diffuse gradually into the adhesive. Therefore, according to the present invention, the first and second bonding layers in which the soft third adhesive is diffused can be easily formed.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a joint structure between an electrode plate terminal and a film pack battery case of a film pack type lead battery according to an embodiment of the present invention.

FIG. 2 is a diagram showing T-shaped peel strength between a film pack battery case of a battery used in a test and a bonded portion of an electrode plate terminal.

FIG. 3 is a diagram showing a state in which a joint portion of an electrolytic solution of a battery used for a test is in a crawling state.

FIG. 4A is a diagram showing a measurement result of a T-shaped peel strength of a junction portion of a battery of one embodiment of the present invention with respect to a film pack battery case, and FIG. 4B is a battery of one embodiment of the present invention It is a figure which shows the measurement result of T-shaped peeling strength with respect to the electrode plate terminal of the joining part of FIG.

5 (A) is a view showing a joint portion between a film plate type lead battery electrode plate terminal and a film pack battery case according to another embodiment of the present invention, and FIG. It is the figure which showed typically the BB line cross section.

FIG. 6 is a diagram illustrating a method of manufacturing a film pack type lead battery according to another embodiment of the present invention.

FIG. 7 is a diagram showing a state in which a joint portion of an electrolyte solution of a battery used in a test is crawling up.

FIG. 8 is a diagram showing the relationship between the bending angle of the joint portion of the battery used in the test and the crack rate of the adhesive layer at the joint portion.

FIG. 9 is a view schematically showing a joint structure of a film plate type lead battery electrode plate terminal and a film pack battery case.

[Explanation of reference numerals] 1,10,101 Film pack battery case 2,20,102 Electrode plates 2a, 20a, 102a Joined parts 3,30,103 First adhesive layer 4,40,104 Second adhesive Layer 5,51,52 Bonding layer

Claims (7)

[Claims] 1. A part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate are joined by a joining structure using an adhesive, A first adhesive layer containing a thermoplastic synthetic resin material showing a high bondability to the synthetic resin body, and a second adhesive containing a resin material showing a high bondability to the portion to be joined of the electrode plate. A film pack type battery configured by stacking an agent layer on each other, wherein a synthetic resin material contained in both adhesive layers is provided at a polymerization part of the first adhesive layer and the second adhesive layer. A film pack type battery, wherein a bonding layer diffused in is formed. 2. The film pack type battery according to claim 1, wherein the thermoplastic synthetic resin material included in the first adhesive layer is a softening material that softens the bonding layer. 3. A part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate are joined by a joining structure using an adhesive, A first adhesive layer containing a thermoplastic synthetic resin material showing a high bondability to the synthetic resin body, and a second adhesive containing a resin material showing a high bondability to the portion to be joined of the electrode plate. A film pack type battery configured by stacking an agent layer, wherein the film pack type battery is softer than the first and second adhesive layers between the first adhesive layer and the second adhesive layer. A third adhesive layer is provided, and a first bonding layer in which materials included in both adhesive layers are mutually diffused is formed at a polymerization portion of the first adhesive layer and the third adhesive layer. A material that is formed and that is included in both adhesive layers at the polymerization portion of the second adhesive layer and the third adhesive layer There film pack type battery in which a second bonding layer diffused into each other is formed. 4. A thermoplastic synthetic material in which a part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate have a bonding property to the synthetic resin body. A film pack type battery is formed by bonding using a first adhesive containing a resin material and a second adhesive containing a thermosetting resin material showing high bonding properties to the bonded portion of the electrode plate. A method of manufacturing, wherein a melting temperature lower than a curing temperature of the second adhesive is used as the first adhesive, and a sheet-shaped or film-shaped bonded body using the first adhesive To form an adhesive polymer layer by stacking the adhesive body on the portion to be joined of the electrode plate via the second adhesive, and melting the adhesive polymer layer by the first adhesive. The second adhesive by heating to a temperature at which the second adhesive cures. After curing, the adhesive polymerization layer is cooled to cure the first adhesive, and then the cured first adhesive and the part of the film pack battery are overlapped and heated. A method of manufacturing a film pack type battery, which comprises joining the both by welding. 5. The film pack according to claim 4, wherein the thermoplastic synthetic resin material softens the hardened first adhesive when diffused into the first adhesive. Type battery manufacturing method. 6. A thermoplastic synthetic material in which a part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate have a bonding property to the synthetic resin body. A film pack type battery is manufactured by bonding using a first adhesive containing a resin material and a second adhesive containing a thermoplastic resin material showing high bondability to the bonded portion of the electrode plate. A sheet-shaped or film-shaped first adhesive body using the first adhesive, and a sheet-shaped or film-shaped second adhesive body using the second adhesive. To make an adhesive polymerization layer by stacking the first adhesive body on the bonded portion of the electrode plate via the second adhesive body, and making the adhesive polymerization layer the first adhesive layer. And after heating to a temperature at which the second adhesive melts, the adhesive polymerization layer It is characterized in that the first and second adhesives are cooled and cured, and then the cured first adhesive and the part of the film pack battery are overlapped and joined by heat welding. And a method for manufacturing a film pack type battery. 7. A thermoplastic composition in which a part of a film pack battery case formed by using a sheet-shaped or film-shaped synthetic resin body and a portion to be joined of an electrode plate have a bonding property to the synthetic resin body. A film pack type battery is formed by bonding using a first adhesive containing a resin material and a second adhesive containing a thermosetting resin material showing high bonding properties to the bonded portion of the electrode plate. A method of manufacturing, wherein a third adhesive containing a thermoplastic synthetic resin material having a melting temperature lower than a curing temperature of the second adhesive and softer than the first and second adhesives is used. A sheet-shaped or film-shaped adhesive body, and the adhesive body is superposed on the bonded portion of the electrode plate via the second adhesive to form an adhesive polymer layer. To a temperature at which the third adhesive melts and the second adhesive hardens. After heating with, the adhesive polymerized layer is cooled to cure the third adhesive, and the cured third adhesive and the third adhesive formed on the surface of the part of the film pack battery case. A method for producing a film pack type battery, characterized in that the adhesive layer (1) is overlaid and the two are joined by heat welding.