JP2002093386A - Package material for lithium battery and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material construction of package materials and a manufacturing method of superb productivity in case of carrying out of die-set punching as a manufacturing process as well as protective physical property of a lithium battery body, as materials for package of the lithium battery. SOLUTION: With the package materials for the lithium battery comprising at least a base material layer, an adhesive layer, a conversion treatment layer, aluminum, an adhesive resin layer, an innermost resin layer, of which, the adhesive resin layer is to be of acid-degeneration polyethylene, the innermost resin layer is to be of medium-density polyethylene with density of 0.935 or higher and of MFR1 to 10 g/sec., and the adhesive resin layer and the innermost resin layer are deposited in common extrusion molding, the conversion treatment includes phosphorus chromate treatment. As the manufacturing method of the same, conversion treatment is applied on both faces of aluminum, the base material and one of the conversion treated faces of aluminum are dry-laminated, and then, the adhesive resin and the innermost resin are extrusion molded together and deposited to make up a laminate, which is heated by post-heating so that the above adhesive reaches above its softening point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material for use in a lithium battery having a liquid-proof, gel-like polymer having a moisture-proof property and content resistance, and a solid electrolyte. This is a configuration of a packaging material and a method of manufacturing the same when accompanied.

[0002]

2. Description of the Related Art A lithium battery, also called a lithium secondary battery, is a battery having a liquid, gel-like polymer, solid polymer, polymer electrolyte, and generating an electric current by moving lithium ions. Substances include those composed of high-molecular polymers. The structure of the lithium secondary battery includes a positive electrode current collector (aluminum, nickel) / a positive electrode active material layer (a metal positive electrode material such as a metal oxide, carbon black, a metal sulfide, an electrolytic solution, and polyacrylonitrile) / an electrolyte layer ( Carbonate-based electrolytes such as propylene carbonate, ethylene carbonate, dimethyl carbonate, and ethylene methyl carbonate; inorganic solid electrolytes composed of lithium salts; gel electrolytes) / Negative electrode active material layers (lithium metal, alloys, carbon, electrolytes, polyacrylonitrile, etc.) It is composed of a polymer negative electrode material) / a negative electrode current collector (copper, nickel, stainless steel) and an outer package that packages them. Lithium batteries are used for personal computers, portable terminal devices (mobile phones, PDAs, etc.), video cameras, electric vehicles, storage batteries for energy storage, robots, satellites, and the like. As the exterior body of the lithium battery, a metal can formed by pressing a metal into a cylindrical or rectangular parallelepiped container, or
A bag-like multilayer film composed of an outermost layer / aluminum / sealant layer was used.

[0003]

However, there have been the following problems as an exterior body of a lithium battery. In a metal can, the shape of the battery itself is determined because the outer wall of the container is rigid. Therefore, since the hardware side is designed according to the battery, the size of the hardware using the battery is determined by the battery, and the degree of freedom of the shape is reduced.
Further, the bag-shaped exterior body made of a multilayer film is not limited in the degree of freedom in the shape design of the hardware using the battery by the battery itself, like the metal can, but is required as the exterior body of the lithium battery. At present, packaging materials that can sufficiently satisfy the physical properties and functions have not yet been developed. The physical properties / functions include moisture proof property, content resistance property, moldability and the like. For example, it has a configuration of a base material layer, a barrier layer, and an innermost resin layer. In the case of a lithium battery, particularly, an adhesive strength between the respective layers is required. In particular, the adhesion between the barrier layer and the innermost resin layer is easily affected by hydrogen fluoride generated by the reaction between lithium, a fluorine compound, or the like, which is a component of the lithium battery, and the outside air (particularly, moisture = moisture). It is required that delamination does not occur for a long time.
Therefore, the lamination of the barrier layer and the innermost resin layer is performed by a dry lamination method, a heat lamination method, or the like. However, these methods have a low laminating speed, and a method with higher productivity has been required. When the innermost layer is laminated by a method in which the adhesive resin and the innermost resin are co-extruded, the productivity is good, but the adhesive strength with aluminum is low, and practical use is difficult. As a method of increasing the adhesive strength, the present inventors coated an aluminum surface with an acid-modified PP emulsion and baked to form a film, and extruded an acid-modified PP resin and an innermost resin on the film surface by co-extrusion. Although it has been confirmed that the required adhesive strength can be obtained by laminating, there was a problem that the processing efficiency was poor due to the coating of the acid-modified PP emulsion and the baking thereof.
In addition, when low-density polyethylene or linear low-density polyethylene is used for the innermost resin layer, when there is a punching step using a die-set type punching die, the laminate is poorly cut, and burrs are generated at the punched portion. In some cases, it became impossible to pull out. An object of the present invention is to provide, as a material for use in lithium battery packaging, a material configuration of a packaging material in the case of performing die-cutting as a processing step, as well as protection physical properties of a lithium battery main body, and a manufacturing method with good productivity. .

[0004]

The present invention comprises at least a substrate layer, an adhesive layer, a chemical conversion layer, aluminum, a chemical conversion layer, an adhesive resin layer, and an innermost resin layer, wherein the adhesive resin layer is made of acid-modified polyethylene. The innermost resin layer has a density of 0.93.
A packaging material for lithium batteries, characterized in that the adhesive resin layer and the innermost resin layer are co-extruded and formed as a medium-density polyethylene having a MFR of 1 to 10 g / sec. Is a phosphoric acid chromate treatment, and the manufacturing method is such that a chemical conversion treatment is performed on both surfaces of aluminum, and a base material and one surface of the aluminum subjected to the chemical conversion treatment are dry-laminated, and then the chemical conversion treatment is performed. Adhesive resin, innermost resin is co-extruded to form a laminate on the other surface that has been treated to form a laminate, and the resulting laminate is post-heated.
A method in which the adhesive resin is heated under the condition of its softening point or more, a chemical conversion treatment is performed on both surfaces of aluminum, and a base material and one surface of the aluminum which has been subjected to the chemical conversion treatment are dry-laminated, and then the chemical conversion treatment is performed. A method of heating the temperature of aluminum to a temperature higher than the softening point of the adhesive resin layer at the time of co-extrusion film formation by forming an adhesive resin and innermost resin on the other surface by co-extrusion to form a laminate. After chemical conversion treatment on one side of the substrate, and dry-lamination of the substrate and the surface of the aluminum that is not subjected to the chemical conversion treatment, the adhesive resin and innermost resin are co-extruded on the surface subjected to the chemical conversion treatment to form a laminate. And, by post-heating the obtained laminate, a method in which the adhesive resin is heated under a condition that its softening point or higher, or a chemical conversion treatment is performed on one surface of aluminum, and the chemical conversion treatment of the substrate and aluminum is performed. After dry laminating the surface not subjected to the treatment, the adhesive resin and the innermost resin are co-extruded to form a laminate on the surface subjected to the chemical conversion treatment to form a laminate. A method for producing a packaging material for a lithium battery, comprising heating the layer to a temperature higher than the softening point of the layer.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention stabilizes the laminating strength of a laminate as a packaging material for a lithium battery and achieves efficient production. It will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating the configuration of a laminate in the packaging material for a lithium battery of the present invention. FIG. 2 is a perspective view illustrating a pouch type exterior body of a lithium battery. FIG. 3 is a perspective view illustrating an embossed exterior body of a lithium battery. Figure 4 illustrates the molding in embossed type, (a) a perspective view, (b) embossing the molded outer body, c) X ₂ -X ₂ parts cross-sectional view, (d) Y ₁
It is a part enlarged view. FIG. 5 is a conceptual diagram illustrating a co-extrusion laminate for producing a packaging material for a lithium battery. FIG. 6 is a perspective view illustrating a method of mounting an adhesive film in bonding a wrapping material for a lithium battery and a tab. The packaging material for a lithium battery is at least a base material layer, a barrier layer, and a laminate including an innermost resin layer.
An intermediate layer may be provided between the base layer and the barrier layer, and between the barrier layer and the innermost resin layer.

When the packaging material for a lithium battery is, for example, nylon / adhesive layer / aluminum / adhesive layer / polyolefin layer (innermost resin layer) and the adhesive layer is formed by a dry lamination method, the exterior of the lithium battery is When the body is of an embossed type, delamination in which the aluminum and the base material layer are separated from each other in the side wall portion in press molding often occurs. Delamination also occurred in the portion to be heat-sealed. Also,
In some cases, hydrogen fluoride generated by the reaction between the electrolyte, which is a component of the battery, and moisture attacks the inner surface of aluminum, causing delamination. The innermost resin layer in the present invention uses a polyethylene resin from the viewpoint of heat sealing properties and the like.

Therefore, the present inventors have proposed a method for embossing,
At the time of heat sealing, it is a laminated body without delamination, and as a result of earnest research on packaging materials that can be satisfied as an exterior body for lithium batteries with content resistance, subjected to chemical conversion treatment on both sides of aluminum, In addition, an acid-modified PE such as an unsaturated carboxylic acid-grafted polyethylene (hereinafter, referred to as an “acid-modified PE”)
PEa) and polyethylene were formed by co-extrusion, and the resulting laminate was post-heated to find that the above problem could be solved. Thus, the present invention was completed.

As shown in FIG. 1, the layer structure of the packaging material for a lithium battery according to the present invention comprises at least a substrate layer 11, an adhesive layer 16, a chemical conversion layer 15 (1), aluminum 12, and a chemical conversion layer 15 (2). ), A laminate comprising an extruded resin layer 13 and an innermost layer 14, wherein the extruded resin layer 13 and the innermost resin layer 14
Is a laminate formed by co-extrusion, and the laminate is heated by post-heating to a temperature higher than the softening point of the adhesive resin.

The innermost resin layer is made of a polyethylene resin because of the stability of heat sealing, suitability for lamination, and the like. In some cases, the type and grade of the innermost resin layer may interfere with punching. For example, if a resin such as low-density polyethylene, linear low-density polyethylene, or the like is used, burrs are generated at the punched portion, resulting in a defective product. Even when medium-density polyethylene is used, the suitability for punching is improved, but problems may occur depending on the grade. Thus, the present inventors have conducted research on a packaging material that enables stable production even in the above-described punching step. As a result, the innermost resin layer has a density of 0.935 or more and an MFR of
It has been found that the use of the high-density polyethylene in 1 to 15 g / 10 seconds stabilizes the punching with the die set type. )

[0010] The lithium battery packaging material is an outer package for packaging the lithium battery body, and there are a pouch type as shown in FIG. 2 and an emboss type as shown in FIG. 3 depending on the type of the outer package. The pouch type includes a bag type such as a three-side seal, a four-side seal, and a pillow type. FIG. 2 illustrates the pouch type as a pillow type.
In addition, as the embossing type, a concave portion may be formed on one side as shown in FIG. 3A, or a concave portion may be formed on both surfaces as shown in FIG. It may be housed and heat-sealed on the four sides of the periphery to seal. There is also a type in which concave portions are formed on both sides of a folded portion as shown in FIG. 3 (c), a lithium battery is housed, and three sides are heat-sealed.

In the present invention, the outermost layer 11 is made of a stretched polyester or nylon film.
Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate. Examples of the nylon resin include polyamide resins, that is, nylon 6, nylon 6,6, a copolymer of nylon 6 and nylon 6,6, nylon 6,10, and polymethaxylylene adipamide (MXD6). Can be

When the outermost layer 11 is used as a lithium battery, it is a portion that is in direct contact with the hardware.
Basically, a resin layer having an insulating property is preferable. In consideration of the existence of pinholes in the film alone and the occurrence of pinholes during processing, the outermost layer 11 needs to have a thickness of 6 μm or more, and a preferable thickness is 12 to 25 μm.

In the present invention, the outermost layer 11 can be laminated to improve the pinhole resistance and the insulation when the battery is used as an outer package. When the outermost layer 11 is laminated, the outermost layer 11 includes at least one or more resin layers, and each layer has a thickness of 6 μm or more, preferably 12 to 25 μm. Although not shown, examples of laminating the outermost layer include the following 1) to 7). 1) Stretched polyethylene terephthalate / stretched nylon 2) Stretched nylon / stretched polyethylene terephthalate Also, mechanical suitability of packaging materials (stability of transport in packaging machines and processing machines), surface protection (heat resistance, electrolyte resistance) When the exterior body for a lithium battery is embossed as a secondary process, the outermost layer is multilayered in order to reduce the frictional resistance between the mold and the outermost layer during embossing, and a fluororesin layer is formed on the outermost layer surface. It is preferable to provide an acrylic resin layer, a silicone resin layer, and the like. For example, 3) a fluorine-based resin layer / stretched polyethylene terephthalate (a fluorine-based resin is formed by drying after film-like or liquid coating) 4) a silicone-based resin / stretched polyethylene terephthalate. The silicone resin is formed by drying after film-like material or liquid coating. 5) Fluorine resin / stretched polyethylene terephthalate /
Stretched nylon 6) Silicone resin / Stretched polyethylene terephthalate / Stretched polyethylene terephthalate / Stretched nylon 7) Acrylic resin / Stretched nylon (Acrylic resin is cured by drying after film-like or liquid coating)

The outermost layer is bonded to the barrier layer by a dry lamination method, an extrusion lamination method, or the like.

The barrier layer 12 is a layer for preventing water vapor from particularly entering the inside of the lithium battery from the outside. The barrier layer 12 stabilizes the pinholes of the barrier layer alone and the workability (pouching, embossing). And, in order to provide pinhole resistance, aluminum having a thickness of 15 μm or more, a metal such as nickel, or an inorganic compound, for example, a film on which silicon oxide, alumina or the like is deposited, and the like.
The barrier layer is preferably aluminum of 15 to 80 μm. To further reduce the occurrence of pinholes, when the type of the exterior body of the lithium battery is embossed, in order to eliminate the occurrence of cracks and the like in the embossed portion, the present inventors, as a barrier layer. The material of aluminum used has an iron content of 0.3 to 9.0.
% By weight, preferably 0.7 to 2.0% by weight, compared to aluminum without iron.
It has been found that aluminum has good extensibility, reduces the occurrence of pinholes due to bending as a laminate, and facilitates formation of side walls when embossing the embossed type exterior body. When the iron content is less than 0.3% by weight, the effects of preventing pinholes and improving the embossability are not recognized, and the iron content of the aluminum exceeds 9.0% by weight. In such a case, the flexibility as aluminum is impaired, and the bag-making properties of the laminate deteriorate.

Further, the aluminum produced by cold rolling has its flexibility and flexibility under annealing (so-called annealing) conditions.
Although the strength and hardness of the waist change, the aluminum used in this embodiment is more rigid than the hard treated product that has not been annealed.
A soft and soft treated product which has been appropriately subjected to annealing is preferable. In addition, the degree of flexibility / strength / hardness, that is, the annealing condition may be appropriately selected in accordance with workability (pouching, embossability). For example, in order to prevent pinholes and wrinkles during embossing, it is better to use aluminum that has a soft tendency to be slightly or completely annealed than a hard processed product that has not been annealed.

Furthermore, the present inventors dissolve and corrode aluminum, especially on the surface of the lithium battery body, due to hydrogen fluoride (chemical formula: HF) generated by the reaction between the electrolyte of the lithium battery and moisture. To prevent the dissolution and corrosion of aluminum oxide, improve the adhesiveness (wetting) of both surfaces of aluminum, and stabilize the adhesive strength between aluminum and the innermost resin layer when forming a laminate On the other hand, it has been found that the formation of the acid-resistant film on the front and back surfaces of the aluminum and the treatment for improving the adhesive force have a remarkable effect on solving the above-mentioned problem.

As shown in FIG. 5, the inner side of the barrier layer 12 in the lithium battery packaging material of the present invention is formed by co-extrusion. 13. The innermost resin 14 is supplied to the extruder 31b, and coextruded from the coextrusion die 32 to form a film and adhere. It is preferable that the innermost resin layers 14 have heat sealing properties, and polyethylene of medium density or higher having necessary physical properties such as heat resistance, moisture resistance and press moldability is used. Then, a PE-based resin is co-extruded as an acid-modified PEa having good adhesion to the chemical conversion treated surface of aluminum to form a laminate.

As the laminate of the packaging material for a lithium battery of the present invention, in addition to the above-mentioned base material layer, barrier layer and innermost resin layer,
An intermediate layer may be provided between the barrier layer and the innermost resin layer.
The intermediate layer improves the strength as a packaging material for lithium batteries,
It may be laminated for improving and stabilizing barrier properties.

The inventors of the present invention have conducted intensive studies on the problem of the present invention. As shown in FIG. 1, as shown in FIG. By performing 1) and 15 (2), a laminate that was satisfactory as the packaging material could be obtained. The chemical conversion treatment 15 is specifically a delamination between aluminum and a substrate layer at the time of embossing by forming an acid-resistant film such as a phosphate, a chromate, a fluoride, and a triazine thiol compound. Prevention and prevention of dissolution and corrosion of the aluminum surface, especially the dissolution and corrosion of aluminum oxide present on the aluminum surface, due to the hydrogen fluoride generated by the reaction between the electrolyte of the lithium battery and moisture. Of the base material layer and aluminum at the time of heat sealing, and the embossing type exhibits an effect of preventing delamination between the base material layer and aluminum at the time of press molding. As a result of studying the effect of chemical conversion treatment on the aluminum surface using various substances, among the above-mentioned acid-resistant film-forming substances, phenolic resin, chromium fluoride (3) compound, and phosphoric acid The obtained aqueous solution was applied to the aluminum surface, and the drying and baking treatment was good. The coating amount is about 10 mg / m ² as a dry weight.

In the case where the exterior body of the lithium battery is of a pouch type, the chemical conversion treatment may be performed only on one side of the innermost layer of aluminum. When the exterior body of the lithium battery is an embossed type, delamination between aluminum and the base layer during embossing can be prevented by performing a chemical conversion treatment on both surfaces of aluminum. A laminate having a chemical conversion treatment on both surfaces of aluminum may be used for the pouch type.

In the production of the packaging material for a lithium battery of the present invention, chemical conversion treatment is performed on both surfaces of aluminum as a barrier layer, and then a substrate is bonded to one of the surfaces subjected to the chemical conversion treatment by dry lamination. Then, the adhesive resin and the innermost resin are extruded on another surface subjected to the chemical conversion treatment by a co-extrusion method to form a film, thereby forming a laminate.

An acid-modified PE is coated on the aluminum chemical conversion treated surface.
When a and PE are co-extruded, the productivity as a laminating process is excellent, but the adhesive strength required for use as a packaging material for a lithium battery cannot be obtained.
The present inventors have conducted intensive studies on a method of improving the adhesive strength, and as a result of heating the obtained laminate, the adhesive strength between the chemical conversion treatment layer and the adhesive resin layer can be increased. Examples of the heating method include a hot roll contact method, a hot air method, a near or far infrared ray method, and any method may be used as long as it can be heated to a temperature higher than the softening point temperature of the adhesive resin.

For the innermost layer of the laminate in the packaging material for a lithium battery of the present invention, medium or high density polyethylene is preferably used. This is because the use of a high-density polyethylene in the innermost layer has good extrusion processability, and is excellent in heat sealability and embossable moldability.

However, since polyethylene does not have a heat-sealing property with respect to metal, the heat-sealing of the tab portion in the lithium battery requires the heat-sealing process shown in FIG. 6 (a), FIG.
As shown in (c), between the tab and the innermost layer of the laminate,
By interposing an adhesive film having heat sealing properties to both the metal and the CPP, the sealing performance at the tab portion is also ensured. The adhesive film may be wound around a predetermined position on a tab as shown in FIGS. 6D, 6E, and 6F. As the adhesive film, the unsaturated carboxy-grafted polyolefin, metal cross-linked polyethylene, ethylene or propylene and acrylic acid,
Alternatively, a film made of a copolymer with methacrylic acid can be used.

In the present invention, when the substrate and the barrier layer are laminated by a dry lamination method, polyester, polyethyleneimine, polyether, cyanoacrylate, urethane, organic titanium, polyether urethane System, epoxy system, polyester urethane system, imide system, isocyanate system, polyolefin system,
Various silicone adhesives can be used.

[0027]

EXAMPLES The packaging material for a lithium battery of the present invention is described below.
Examples will be described more specifically. Chemical conversion treatment
Displacement may also be caused by phenol resin, chromium fluoride
(3) Roll coating with an aqueous solution comprising a compound and phosphoric acid
Condition by which the coating temperature is 180 ℃ or higher
Baked in Chromium coating amount is 10mg / m^Two
(Dry weight). Example 1, Comparative Example 1, and Comparative Example
3 is a pouch type exterior body, each of which is 50 mm
A pillow-type pouch with a width and length of 80 mm is made.
Then, the lithium battery main body was stored and hermetically sealed. Ma
Example 2, Comparative Example 2 and Comparative Example 4 were embossed.
The emboss is a single-sided embossed type.
Then, the shape of the concave portion (cavity) of the mold is 30 mm × 5
0mm, depth 3.5mm, press forming and moldability
Was evaluated. In each case, the tab of the lithium battery was
A 20 μm thick unsaturated film
A film made of carboxylic acid grafted polyethylene
The sheet was wound around a seal portion of the tab and heat-sealed. [Example 1] (Pouch type, die set type removal)
Yes) Chemical conversion treatment is applied to both sides of aluminum 20μm.
Stretched polyester film on one side
Laminated by the minate method, and then
On the other side of minium, an acid-modified linear low point with a softening point of 105 ° C
Density polyethylene 15μm (acid-modified LLDPE) and MD
PE (density 0.935, MFR 5 g / 10 sec) 30 μm
And the acid-modified LLDPE side is
Laminate to obtain a minium surface, resulting laminate
Is heated so that the surface temperature of aluminum becomes 130 ° C.
Thus, Sample Example 1 was obtained. [Example 2] (Removal of emboss type and die set type)
Yes) Chemical conversion treatment on both sides of 40μm aluminum
Dry laminating 25μm nylon on one side
And then soften the other surface
Acid-modified medium-density polyethylene with a crystallization point of 110 ° C 12 μm
(Acid-modified MDPE) and MDPE (density 0.942, MF
R10g / 10 sec) 30 μm and coextrusion method
Laminate so that the acid-modified MDPE side is an aluminum surface.
And the resulting laminate is heated to a surface temperature of aluminum.
The sample was heated to 140 ° C. to obtain Sample Example 2. [Comparative Example 1] (pouch type) A chemical conversion treatment was performed on both surfaces of aluminum 20 μm.
Stretched polyester film on one side
Laminated by the minate method, and then
Acid-modified low density with a softening point of 105 ° C on the other side of minium
Polyethylene 15μm (acid-modified LLDPE) and MDPE
(Density 0.935, MFR 5 g / 10 sec) 30 μm
By the co-extrusion method, the acid-modified LLDPE side
Laminate so that the sample surface is
Example 1 was used. [Comparative Example 2] (Embossed type) A chemical conversion treatment was performed on both surfaces of 40 μm aluminum.
Dry laminating 25μm nylon on one side
And then soften the other surface
Acid-modified medium-density polyethylene with a crystallization point of 110 ° C 12 μm
(Acid-modified MDPE) and MDPE (density 0.942, MF
R10g / 10 sec) 30 μm and coextrusion method
Laminate so that the acid-modified MDPE becomes an aluminum surface.
The coated laminate was designated as Sample Comparative Example 2. [Comparative Example 3] (pouch type) Stretched polyester film on one surface of aluminum 20 µm
The film is laminated by dry lamination and then
An acid-modified line with a softening point of 105 ° C on the other side of aluminum
Low density polyethylene 15μm (acid-modified LLDPE)
MDPE (density 0.935, MFR 5 g / 10 sec) 30
μm by the co-extrusion method.
Laminated so that the PE) side is an aluminum surface
Then, the obtained laminate is heated to an aluminum surface temperature of 150.
C. to obtain a sample comparative example 3. [Comparative Example 4] (Embossed type) Nylon 25 µm on one side of aluminum 40 µm
Lamination by dry lamination, then aluminum
Acid-modified medium density polyethylene with a softening point of 110 ° C
Len 12 μm (acid-modified MDPE) and MDPE (density 0.
942, MFR 10 g / 10 sec) co-extrusion with 30 μm
Method, the acid-modified MDPE side becomes an aluminum surface.
And laminate the resulting laminate with aluminum
Samples heated by heating so that the surface temperature of the sample becomes 150 ° C
3 was obtained. [Comparative Example 5] (Pouch type, die set type removal)
Yes) Chemical conversion treatment is applied to both sides of aluminum 20μm.
Stretched polyester film on one side
Laminated by the minate method, and then
Acid-modified low density with a softening point of 105 ° C on the other side of minium
Polyethylene 15μm (acid-modified LDPE) and LDPE
(Density 0.915, MFR 5 g / 10 sec) 30 μm
By the co-extrusion method, the acid-modified PEa side is made of aluminum.
And laminate the resulting laminate to aluminum
Heat the sample so that its surface temperature becomes 130 ° C
Comparative Example 5 was obtained. [Comparative Example 6] (Removal of emboss type and die set type)
Yes) Chemical conversion treatment on both sides of 40μm aluminum
Dry laminating 25μm nylon on one side
And then soften the other surface
Acid-modified medium-density polyethylene with a crystallization point of 110 ° C 12 μm
(Acid-modified MDPE) and MDPE (density 0.934, MF
R20g / 10 sec) 30μm and coextrusion method
Laminate so that the acid-modified MDPE side is an aluminum surface.
And the resulting laminate is heated to a surface temperature of aluminum.
The sample was heated to 140 ° C. to obtain Sample Comparative Example 6. <Embossing and packaging> Example 1 of each sample obtained, ratio
In Comparative Examples 1 and 3, bags were made as pouches.
2, Comparative Example 2, Comparative Example 4 and Comparative Example 6 are press molded
And wrap each lithium battery body and
went. <Evaluation method> 1) Delamination during molding Immediately after molding, delamination between aluminum and substrate layer
Was checked. 2) Content resistance As a storage condition, each sample was subjected to a constant temperature of 60 ° C. and 90% RH.
After storing in the tank for 7 days,
The presence or absence of delamination with propylene was confirmed. 3) Delamination during heat sealing Delamination between aluminum and innermost resin layer immediately after heat sealing
The presence or absence of the termination was confirmed. 3) Suitability for punching Die set punching die (male and female clearer)
(Pull 10mm, push-in amount 1mm)
It is determined whether or not it is possible. <Results> In both Examples 1 and 2, when embossing,
No delamination during heat sealing.
No delamination due to the contents was observed.
In both Comparative Example 1 and Comparative Example 2,
No delamination was observed. Comparative Example 2
There was no delamination during embossing. I
However, in both Comparative Examples 1 and 2, delamination on the contents side was performed.
Nations were observed in all of the 100 samples. However
The delamination on the side of the contents is
It is not due to food, but the chemical conversion surface and the acid-modified PP layer
Interfacial peeling was observed. In both Comparative Examples 3 and 4, heat was applied.
When sealing, 40 and 46 samples out of 100
Laminated, embossed in Comparative Example 4
During molding, delaminate to 22 out of 100 samples each
Was approved. In addition, data caused by resistance to contents
Lamination was observed in all of the 100 samples.
Delamination on the contents side causes corrosion of aluminum surface
Was caused. Also, die set type removal
As a result, both Example 1 and Example 2 passed without any problem.
Although Comparative Example 5 and Comparative Example 6 could be processed
Burrs occurred in all the punched portions of each 100 samples. Ma
In Comparative Example 5, 98 out of 100 samples were compared.
In Example 6, 25 samples out of 100 samples remained (extracted)
There is a part that can not be cut off).

[0028]

The chemical conversion treatment applied to both surfaces of aluminum in the lithium battery packaging material of the present invention prevents the occurrence of delamination between the substrate layer and aluminum during embossing and heat sealing. In addition, by preventing corrosion of the aluminum surface due to hydrogen fluoride generated by the reaction between the electrolyte of the lithium battery and moisture, a remarkable effect of preventing delamination of aluminum with the content-side layer can also be prevented. Is shown.
In addition, since the innermost resin layer can be formed and laminated at the same time, the productivity is good, and the post-heating treatment can obtain the adhesive strength as a packaging material for a lithium battery and can be used as an exterior body of a lithium battery. Can be. When a die-set type punching step is performed, the grade of the polyethylene resin used for the heat seal layer is set to a density of 0.9.
By setting the MFR at 35 or more and 1 to 15 g / 10 seconds, it was possible to perform an operation without defective punching.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a laminate in a packaging material for a lithium battery of the present invention.

FIG. 2 is a perspective view illustrating a pouch type exterior body of a lithium battery.

FIG. 3 is a perspective view illustrating an embossed type exterior body of a lithium battery.

FIG. 4 illustrates molding in an emboss type.
(A) a perspective view, (b) an embossed exterior body body,
(C) X ₂ -X ₂ parts cross-sectional view, an enlarged view (d) Y ₁ parts.

FIG. 5 is a conceptual diagram illustrating a co-extrusion laminate for producing a packaging material for a lithium battery.

FIG. 6 is a perspective view illustrating a method of mounting an adhesive film in bonding a packaging material for a lithium battery and a tab.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lithium battery 2 Lithium battery main body 3 Cell (power storage part) 4 Tab (electrode) 5 Exterior body 6 Adhesive film (tab part) 7 Concave part 8 Side wall part 9 Seal part 10 Laminated body (packaging material for lithium battery) 11 Base material layer 12 Aluminum (barrier layer) 13 Adhesive resin layer 14 Inner resin layer 15 Chemical conversion layer 16 Adhesive layer 20 Press forming part 21 Male type 22 Female type 23 Cavity 30 Co-extrusion laminating device 31 Extruder 32 Die 33 Molten resin film 34 Chill roll 35 Crimping roll 36 Laminating substrate 37 Material to be laminated

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B29K 23:00 B29K 23:00 B29L 9:00 B29L 9:00 (72) Inventor Kazuki Yamada Shinjuku-ku, Tokyo 1-1-1 Ichigaya Kagacho Dai Nippon Printing Co., Ltd. (72) Inventor Hiroshi Miyama 1-1-1 Ichigaya Kagamachi Shinjuku-ku, Tokyo Dai-Nippon Printing Co., Ltd. F term (reference) 4F100 AA04C AA22C AB10B AK01D AK01E AK04D AK06E AK41 AK48 AK63 AL07D AR00C AT00A BA05 BA07 BA10A BA10E EH012 EH20D EH20E EH202 EH232 EJ37 EJ422 EJ68C EJ681 EJ69C GB15 GB41 JA06E JA13E JB02 JK06 JL02 JL11D YY00E 4F207 AA04J AA07C AA08 AD03 AD08 AD20 AG03 AH33 AH54 AH58 AR06 KA01 KA17 KB11 KB26 KK51 KM01 5H011 AA09 AA10 CC02 CC06 CC10 DD01 DD09 DD21 KK00 KK06 5H029 AJ07 AJ14 AK02 AK05 AK16 AL12 AL16 AM03 AM07 BJ04 CJ02 C J06 CJ14 DJ02 EJ01 EJ12 HJ08 HJ14

Claims (6)

[Claims] (1) at least a substrate layer, an adhesive layer, a chemical conversion treatment layer,
Aluminum, a chemical conversion layer, an adhesive resin layer, an innermost resin layer, the adhesive resin layer is an acid-modified polyethylene, and the innermost resin layer is a medium-density polyethylene having a density of 0.935 or more and an MFR of 1 to 10 g / sec. A packaging material for a lithium battery, wherein the adhesive resin layer and the innermost resin layer are layers formed by coextrusion. 2. The packaging material for a lithium battery according to claim 1, wherein the chemical conversion treatment is a phosphoric acid chromate treatment. 3. A chemical conversion treatment is performed on both surfaces of aluminum, and a base material and one surface of the aluminum that has been subjected to the chemical conversion treatment are dry-laminated, and then the other surface of the chemical conversion treatment is bonded with an adhesive resin. The resin is co-extruded to form a film to form a laminate,
A method for producing a packaging material for a lithium battery, wherein the obtained laminate is heated by post-heating under the condition that the adhesive resin has a softening point or higher. 4. A chemical conversion treatment is performed on both surfaces of aluminum, and a base material and one surface of the aluminum that has been subjected to the chemical conversion treatment are dry-laminated, and then the other surface of the chemical conversion treatment is bonded with an adhesive resin. The resin is co-extruded to form a film to form a laminate,
A method for producing a packaging material for a lithium battery, comprising heating aluminum at a temperature equal to or higher than the softening point of the adhesive resin layer during coextrusion film formation. 5. A chemical conversion treatment is performed on one surface of aluminum, and a base material and a surface of the aluminum not subjected to the chemical conversion treatment are dry-laminated, and then an adhesive resin and an innermost resin are co-extruded on the chemical conversion-treated surface. A method for producing a packaging material for a lithium battery, wherein a film is formed into a laminate, and the obtained laminate is heated by post-heating under a condition in which the adhesive resin has a softening point or higher. 6. A chemical conversion treatment is performed on one surface of aluminum, and after a base material and a surface of the aluminum not subjected to the chemical conversion treatment are dry-laminated, an adhesive resin and an innermost resin are co-extruded on the chemical conversion-treated surface. A method for producing a packaging material for a lithium battery, characterized in that the aluminum is heated to a temperature equal to or higher than the softening point of the adhesive resin layer during the co-extrusion film formation by forming a film into a laminate.