JP2002216714A - Packaging material for lithium ion battery and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a packaging material of a lithium ion battery using a material of which a protection physical property of a lithium ion battery body is good and the productivity is good at an emboss forming step or the like as a material used for a lithium ion battery packaging. SOLUTION: The packaging material for lithium ion battery is composed of a laminated body comprising at a least a base material layer, an adhesive layer, a chemical conversion treatment layer 1, aluminum, a chemical conversion treatment layer 2 an acid-modified polyolefin layer and a polyolefin layer. An aliphatic acid amide type slipping agent is coated on at least a surface of the base material layer. In the manufacturing method, both surfaces of aluminum are subjected to degreasing and a chemical conversion treatment layer is provided thereon. Thereafter, the base material layer is provide on one surface by a dry laminating method, an emulsion of acid-modified polyolefin is coated, dried and baked on the other surface and a polyolefin film is heat- laminated on a coated surface, thereby the laminated body is formed. The aliphatic acid amide type slipping agent is coated on at least a surface of the base material layer of the laminated body.

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 a lithium ion battery having a liquid or solid organic electrolyte (polymer polymer electrolyte) having moisture resistance and content resistance.

[0002]

2. Description of the Related Art A lithium ion battery, also called a lithium secondary battery, is a battery having a polymer electrolyte and generating an electric current by the movement of lithium ions.
The negative electrode active material includes one composed of a polymer. The structure of the lithium secondary battery is as follows: a positive electrode current collector (aluminum, nickel) / a positive electrode active material layer (a metal positive electrode material such as metal oxide, carbon black, metal sulfide, electrolyte solution, polyacrylonitrile) / an electrolyte layer (propylene) Carbonate-based electrolytes such as carbonate, ethylene carbonate, dimethyl carbonate, ethylene methyl carbonate,
Inorganic solid electrolyte composed of lithium salt, gel electrolyte) / Negative electrode active material (lithium metal, alloy, carbon, electrolyte,
It is composed of a polymer negative electrode material such as polyacrylonitrile) / a negative electrode current collector (copper, nickel, stainless steel) and an outer package for packaging them. Applications of lithium-ion batteries include personal computers, mobile terminal devices (mobile phones, PDAs, etc.),
Video cameras, electric vehicles, storage batteries for energy storage,
Used for robots, satellites, etc. As the exterior body of the lithium-ion battery, a metal can formed by pressing a metal into a cylindrical or rectangular parallelepiped container, or a base layer,
A bag made of a laminate composed of aluminum and a sealant layer has been used.

[0003]

However, there are the following problems as an exterior body of a lithium ion 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 to match 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. Therefore, a pouch type in which the laminate is stored in a bag shape and the lithium ion battery body is housed, or an emboss type in which the laminate is press-formed to form a recess and the lithium ion battery body is housed in the recess, has been developed. . The embossed type provides a more compact package as compared to the pouch type. Regardless of the type of exterior body, the moisture-proof or puncture-resistant strength, insulation, and the like of the lithium-ion battery are indispensable for the exterior body of the lithium-ion battery. And
In general, a packaging material for a lithium ion battery is a laminate including at least a base material layer, a barrier layer, and a heat seal layer. Further, it has been confirmed that the adhesive strength between the respective layers has an influence on properties required as an exterior body of the lithium ion battery. For example, if the adhesive strength between the barrier layer and the heat sealing layer is insufficient, it causes moisture to enter from the outside, and the fluoride generated by the reaction between the electrolyte in the components forming the lithium ion battery and the moisture. Hydrogen acid corrodes the aluminum surface, causing delamination between the barrier layer and the heat seal layer. Also, when the embossed type exterior body,
The laminate is press-molded to form a concave portion. During this molding, delamination may occur between the base material layer and the barrier layer. In addition, when stretched nylon is used as the base material layer, in embossing, the coefficient of friction between the forming female mold and the base material layer is large, and molding wrinkles and cuts may occur. An object of the present invention is to provide a method for manufacturing a packaging material for a lithium ion battery, which has good productivity in an embossing step and the like, as well as the protective properties of the lithium ion battery body as a material used for the lithium ion battery packaging.

[0004]

The above objects can be attained by the present invention described below. At least a substrate layer,
Adhesive layer, chemical conversion layer 1, aluminum, chemical conversion layer 2,
An acid-modified polyolefin layer, a laminate comprising a polyolefin layer, and a packaging material for a lithium-ion battery, wherein at least the surface of the base material layer is coated with a fatty acid amide-based slip agent; This includes that the layer is made of polypropylene, the polyolefin layer is made of polyethylene, the slip agent is erucic acid amide, and the slip agent is oleic acid amide. Also,
The manufacturing method is that after degreasing both surfaces of aluminum, providing a chemical conversion treatment layer, providing a base material layer on one surface by a dry lamination method, applying and drying and baking an emulsion of an acid-modified polyolefin on the other surface, A method for coating a fatty acid amide slip agent on at least the surface of the substrate layer of the laminate by forming a laminate by heat laminating a polyolefin film on the coated surface, degreasing both surfaces of aluminum, and forming a chemical conversion treatment layer After being provided, a base layer is provided on one side by a dry lamination method, and on the other side, a laminate obtained by sandwich laminating a polyolefin film with an acid-modified polyolefin as an adhesive resin layer is a softening point of the acid-modified polyolefin or more. And then a fatty acid amide slip agent is applied to at least the surface of the base material layer of the laminate. After degreasing both surfaces of aluminum and providing a chemical conversion treatment layer, a base layer is provided on one surface by dry lamination, and on the other surface, an acid-modified polyolefin is used as an adhesive resin layer as a polyolefin film. When sandwich laminating, the surface temperature of aluminum, which is the extruded surface of the acid-modified polyolefin, is heated to a temperature equal to or higher than the softening point of the acid-modified polyolefin resin to laminate the laminate, and at least the base layer of the laminate is formed. The method includes coating the surface with a fatty acid amide-based slip agent, and further includes the step of coating the slip agent immediately before embossing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a moisture-proof property,
Further, it is a packaging material for a lithium ion battery which has good productivity and is less likely to cause cracks in the heat seal layer. The layer configuration and the manufacturing method of the laminate will be described in more detail with reference to the drawings and the like. FIG. 1 is a cross-sectional view showing the structure of the laminate in the packaging material for a lithium ion battery of the present invention according to a lamination method, in which (a) a heat lamination method and (b) a sandwich lamination method are used. FIG.
FIG. 2 is a perspective view illustrating an embossed type exterior body of a lithium ion battery. FIGS. 3A and 3B are views for explaining molding in the emboss type, (a) a perspective view, (b) an exterior body main body formed by embossing, (c) a cross-sectional view of a part X ₂ -X ₂ , and (d) Y _1.
It is a part enlarged view. FIG. 4 is a perspective view illustrating a pouch type exterior body of a lithium ion battery. FIG. 5 is a perspective view illustrating a method of mounting an adhesive film in bonding a packaging material for a lithium ion battery and a tab.

[0006] The packaging material for a lithium ion battery forms an outer package for packaging a lithium ion battery body, and depending on the type of the outer package, FIGS.
There are an embossed type as shown in FIG. 2B or FIG. 2C and a pouch type as shown in FIG. FIG. 4 is a perspective view illustrating a pouch type exterior body of a lithium ion battery. The pouch type includes a bag type such as a three-sided seal, a four-sided seal, and a pillow type.
Is illustrated as a pillow type. The packaging material for a lithium ion battery of the present invention is a laminate particularly suitable for the embossed type exterior body. Fig. 2 for embossed type
As shown in (a), a concave portion may be formed on one side,
As shown in FIG. 2B, recesses may be formed on both sides to accommodate the lithium-ion battery main body, and heat-sealed the four sides of the periphery. There is also a type in which concave portions are formed on both sides of a folded portion as shown in FIG. 2 (c), a lithium ion battery is housed, and three sides are heat-sealed.

The packaging material for a lithium ion battery is, for example, nylon / adhesive layer / aluminum / adhesive layer / heat seal layer, and the heat seal layer is sandwich laminated.
When formed by a dry lamination method, a co-extrusion lamination method, a heat lamination method, or the like, when the exterior body of the lithium-ion battery is an embossed type, in the press molding, the gap between the aluminum and the base material layer is separated at the side wall. Delamination often occurred, and delamination also occurred at a portion where the lithium ion battery main body was housed in an outer package and the periphery thereof was heat-sealed. In addition, hydrogen fluoride generated by a reaction between an electrolyte, which is a component of the battery, and moisture may attack the inner surface of aluminum and cause delamination. In addition, it is preferable to use random polypropylene as the heat seal layer from the viewpoint of the protection property of the lithium ion battery, the stability of heat seal, the laminating property, the economical efficiency, and the like. And the effect of preventing the generation of cracks over time, but the slip with the male mold at the time of embossing was deteriorated, wrinkles were generated, and it was difficult to perform a stable forming operation.

Therefore, the present inventors have found that the embossability is good,
As a result of intensive research on a packaging material that does not cause delamination between the base material layer and the barrier layer, and that can be used as an exterior body for lithium-ion batteries with content resistance, as a result of extensive research, it has been formed on both surfaces of aluminum. On the chemical conversion treatment surface on the content side of aluminum, an emulsion liquid of an acid-modified polyolefin is applied, dried and baked, and then a film made of an acid-modified polyolefin is heat-laminated to form a delamination. It has been found that generation can be prevented.

As another laminating method on the aluminum content side, an unsaturated carboxylic acid-grafted polyolefin and a polyolefin (film or resin) are used.
After laminating by a sandwich lamination method or a co-extrusion method, the inventors have found that the above problem can be solved by heating the obtained laminate.

The layer structure of the packaging material for a lithium ion battery of the present invention is as shown in FIG.
At least the base material layer 11, the adhesive layer 17, the chemical conversion layer 14
(1) A laminated body 10 composed of aluminum 12, a chemical conversion treatment layer 14 (2), and a heat seal layer 13. The adhesion between the heat seal layer 13 and the chemical conversion treatment layer 14 (2) is performed by a heat lamination method, a sandwich method, or the like. Lamination is performed by one of a lamination method and a co-extrusion lamination method. Figure 1
(A) shows a laminate in which an emulsion of an acid-modified polyolefin is applied to a chemical conversion treatment surface on the content side of aluminum, dried and baked, and then, for example, a heat seal layer 13 made of an acid-modified polyolefin is thermally laminated. FIG. FIG. 1B is a cross-sectional view illustrating a layer configuration of a laminate obtained by using a sandwich lamination method or a co-extrusion lamination method. Further, when the sandwich laminating method or the co-extrusion laminating method is used among the above laminating methods, the obtained laminate is pre-heated or post-heated to improve the adhesive strength.

When the packaging material for a lithium ion battery is embossed, the laminate 10 is press-formed to form the recess 7 as shown in FIG. At this time, if the slip between the press-formed female mold 22 and the base material layer 11 of the laminate 10 is poor, a stable molded product may not be obtained. As the base layer 11 of the embossed type exterior body, a stretched nylon film excellent in moldability, strength, and the like is often used, but the nylon film has poor slippage. Embossing may cause wrinkles or breakage in embossing, which may cause poor molding. The present inventors have conducted intensive studies and found that the surface of the base material layer 11 is coated with a fatty acid amide-based slip agent to form the slip agent layer 18 so that the female mold during embossing and the surface layer of the exterior body are formed. They found that the slipperiness was improved and the molding was stable, and the present invention was completed. As a slip agent coated on the base material layer, a fatty acid amide is diluted to a concentration of 0.1 to 10% in a solvent such as isopropyl alcohol, ethyl acetate, toluene, methyl-ethyl-ketone, and roll-coated or sprayed. To form on the substrate 11. As the fatty acid amide to be used, oleic acid amide, erucic acid amide, stearic acid amide, behenic acid amide, ethylenebisoleic acid amide, ethylenebiserucic acid amide, and the like are used. If the amount of the fatty acid amide to be coated or sprayed is 0.1 mg or more per square meter, a sufficient effect can be obtained, and if the amount is 10 g or less per square meter, contamination of the mold for embossing and contamination of the heat sealing device can be obtained. Can be prevented. The entire surface of the base material layer may be coated or sprayed, or only the portion to be embossed in the mold may be coated or sprayed. Further, the laminate film may be coated or sprayed in advance and wound up and stored, but it may be coated or sprayed immediately before molding and used.

The application of the fatty acid amide may be performed after the formation of the laminate, or may be applied by a spray method or the like immediately before molding in an embossing machine.

In the present invention, the base material layer 11 is made of a stretched polyester or nylon film. At this time, as the polyester resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolyester, Polycarbonate and the like. As nylon, polyamide resin, that is, nylon 6,
Nylon 6,6, a copolymer of Nylon 6 and Nylon 6,6, Nylon 6,10, polymethaxylylene adipamide (MXD6) and the like.

When the base material layer 11 is used as a lithium ion battery, it is a portion which is in direct contact with the hardware, so that a resin layer having an insulating property is basically preferable. Considering the existence of pinholes in the film alone and the occurrence of pinholes during processing, for example, stretched nylon or the like is suitably used as the base material layer 11. In the case of a stretched nylon base material layer, a thickness of 6 μm or more is required, and a preferred thickness is 12 to 25 μm.

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

The barrier layer 12 is a layer for preventing water vapor from particularly entering the inside of the lithium ion battery from the outside. The barrier layer 12 has a pinhole and a workability (pouching, embossability) of the barrier layer alone. To stabilize, and to have a pinhole resistance aluminum or metal having a thickness of 15 μm or more, such as nickel, or an inorganic compound, for example,
A film on which silicon oxide, alumina, or the like is deposited is also used, but the barrier layer 12 preferably has a thickness of 20 to 8 mm.
0 μm aluminum. When the type of the exterior body of the lithium ion battery is further improved by improving the generation of pinholes and the type of the exterior body of the lithium ion battery is embossed, the present inventors use the barrier layer 12 in order to eliminate the occurrence of cracks and the like in embossing. The material of aluminum has an iron content of 0.3 to 9.0% by weight, preferably 0.7 to 2.0%.
By setting the weight%, compared with aluminum containing no iron, the extensibility of aluminum is good, the occurrence of pinholes due to bending as a laminate is reduced, and when forming the embossed type exterior body, It has been found that the formation of the side wall can be easily performed. When the iron content is less than 0.3% by weight, effects such as prevention of pinhole generation and improvement of 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 the present invention is harder than the hard treated product without annealing.
Aluminum with a tendency to soften slightly or completely annealed is preferred. The degree of flexibility, waist strength, and hardness of aluminum, that is, the conditions of annealing,
What is necessary is just to select suitably according to workability (pouching, embossing). For example, in order to prevent wrinkles and pinholes during embossing, soft aluminum annealed according to the degree of shaping can be used.

In response to the problem of the present invention, the inventors of the present invention have conducted intensive studies, and as a result, the chemical conversion treatment layer 14 was formed on the front and back surfaces of aluminum which is the barrier layer 12 of the packaging material for lithium ion batteries.
By providing this, it was possible to obtain a laminate 10 which was satisfactory as the packaging material. The chemical conversion treatment is specifically to prevent delamination between aluminum and the substrate layer during embossing by forming an acid-resistant film such as a phosphate, a chromate, a fluoride, and a triazine thiol compound. And hydrogen fluoride generated by the reaction between the electrolyte of the lithium-ion battery and moisture, to prevent the dissolution and corrosion of the aluminum surface, especially the dissolution and corrosion of aluminum oxide present on the aluminum surface, and To improve delamination between the base layer 11 and the aluminum 12 at the time of embossing and heat sealing, and at the inner surface of the aluminum by the hydrogen fluoride generated by the reaction between the electrolyte and moisture. An effect of preventing delamination was obtained. 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 phosphoric acid chromate treatment using the treated product was good. Alternatively, a chemical conversion treating agent containing a metal such as molybdenum, titanium, zircon, or a metal salt in a resin component containing at least a phenol resin was good.

When the exterior body of the lithium ion battery is an embossed type, by forming a chemical conversion treatment on both sides of aluminum, it is possible to prevent delamination between the aluminum 12 and the base layer 11 during embossing. it can.

In the case where the acid-modified polypropylene resin 16 and the heat seal layer (polypropylene film) 15 are laminated on the chemical conversion treatment layer 14 by a sandwich lamination method or when they are laminated by a co-extrusion method,
The adhesiveness of the extruded acid-modified polypropylene resin to the chemical conversion treated surface is poor, and as a countermeasure, the present inventors applied an emulsion of the acid-modified polypropylene to the chemical conversion treated surface by a roll coating method or the like, and after drying, After baking at a temperature of 170 to 200 ° C., it was confirmed that when the laminate was formed by co-extrusion, the adhesive strength was improved.

The substrate layer 11 and one side of the barrier layer 12 chemically converted on both sides are dry-laminated, and an acid-modified polyolefin 16 is extruded on the other side of the barrier layer 12 to sandwich a heat seal layer (polypropylene film) 13. When laminating, the acid-modified polypropylene resin 16 and the heat seal layer (polypropylene resin) 13 are co-extruded to form a laminate, and the laminate is heated to a condition at which the acid-modified polypropylene resin has a softening point or higher. Thus, a laminate having a predetermined adhesive strength could be obtained. As a specific method of the heating, there are methods such as a hot roll contact type, a hot air type, near or far infrared rays, but any heating method may be used in the present invention, and as described above, the adhesive resin is softened. What is necessary is just to be able to heat above the point temperature.

As another method, the above-mentioned sandwich lamination or co-extrusion lamination is carried out by heating the aluminum 12 to such a condition that the surface temperature on the heat seal layer side reaches the softening point of the acid-modified polypropylene resin. Also, a laminate having stable adhesive strength could be obtained. When an adhesive resin layer is required, an acid-modified polypropylene resin is used when the heat seal layer is a polypropylene resin, and an acid-modified polyethylene or polyethylene resin is used when the heat seal layer is a polyethylene resin. When a polyethylene resin is used as the adhesive resin, the extruded polyethylene molten resin film is laminated while the laminating surface on the aluminum side is treated with ozone.

As the laminate 10 of the packaging material for a lithium ion battery of the present invention, the base material layer 11, the barrier layer 12,
In addition to the acid-modified polyolefin layer 17 and the heat seal layer 13 (polypropylene or polyethylene), an intermediate layer made of a biaxially stretched film such as polyimide or polyethylene terephthalate is provided between the acid-modified polyolefin layer 16 and the heat seal layer 13. You may. The intermediate layer is used for improving strength as a packaging material for lithium ion batteries, improving and stabilizing barrier properties, and preventing a short circuit caused by contact between the tab 4 and the barrier layer 12 during heat sealing of the lithium ion battery exterior body. May be stacked.

Each of the above-mentioned layers in the laminate of the present invention includes:
Appropriate surface activation such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc. for the purpose of improving and stabilizing the suitability for film forming, lamination processing, and final processing of secondary products (pouching, embossing) as appropriate. Processing may be performed.

The heat seal layer 13 of the laminate in the packaging material for a lithium ion battery of the present invention has a single-layer film formed from a polyolefin resin, that is, a resin such as random propylene, homopropylene, block propylene, or the like. It is used as a single-layer film formed from a resin obtained by blending the above-mentioned resins, or as a multilayer film thereof. As the heat seal layer 13, random propylene is preferably used. Alternatively, it can be used as a single-layer or multilayer film of linear low-density polyethylene or medium-density polyethylene, or as a single-layer or multilayer film of linear low-density polyethylene or medium-density polyethylene blend resin. Each type of polypropylene, namely, random propylene, homopropylene, block propylene and linear low-density polyethylene, medium-density polyethylene, low-crystalline ethylene butene copolymer, low-crystalline propylene butene copolymer, A terpolymer composed of a ternary copolymer of ethylene, butene and propylene, an anti-blocking agent (AB agent) such as silica, zeolite, and acrylic resin beads, and a fatty acid amide-based lubricant may be added. A butene component, a terpolymer component comprising a ternary copolymer of ethylene, butene, and propylene, a low-crystalline ethylene-butene copolymer having a density of 900 kg / m ³ , an amorphous ethylene-propylene copolymer, A propylene-α-olefin copolymer component or the like may be added. As the heat seal layer 13, it is preferable to use the above-mentioned random polypropylene, which has a good heat seal property between the random polypropylenes, a heat seal property of the lithium ion battery packaging material such as a moisture proof property and a heat resistance property. It has the required protective physical properties as the layer 13 and also has good laminating processability and embossing processability. The random polypropylene used for the heat seal layer 13 includes (1) a density of 0.90 g / c.
m ³ or more, bigat softening point 115 ° C. or more, melting point 120 ° C.
The above is desirable. The linear low-density polyethylene or medium-density polyethylene used for the heat seal layer 14 is desirably (1) one having a density of 0.91 g / cm ³ or more, a bigat softening point of 70 ° C. or more, and a melting point of 110 ° C. or more.

The random polypropylene may be a general random polypropylene having an ethylene content of 3 to 4%, but more preferably an ethylene-rich polypropylene having an ethylene content of 5 to 10%. Heat seal layer 13 made of random polypropylene
By so doing, flexibility is imparted, bending resistance is improved, and cracks are prevented during molding.

As a method for laminating the barrier layer and the heat sealing layer forming the laminate of the packaging material for a lithium ion battery of the present invention, a sandwich laminating method, a co-extrusion laminating method and the like can be used.

However, since random polypropylene and polyethylene do not have heat-sealing properties with respect to metal, the heat-sealing of the tab portion in the lithium-ion battery requires heat-sealing as shown in FIGS. 5 (a), 5 (b) and 5 (c). As shown in the figure, between the tab and the heat seal layer of the laminate, metal and P
By interposing the heat-sealing adhesive film 6 with both of E and E, the sealing property at the tab portion is also ensured. The adhesive film is shown in FIG.
(E), as shown in FIG. 5 (f), the tab 4 may be wound around a predetermined position. As the adhesive film 6,
A film made of the unsaturated carboxy-grafted polyolefin, metal cross-linked polyethylene, or a copolymer of ethylene or propylene with acrylic acid or methacrylic acid can be used.

The base material 11 and the chemical conversion-treated surface of the barrier layer 12 in the packaging material for a lithium ion battery of the present invention are desirably bonded by a dry lamination method.
Examples of the adhesive used for dry lamination of the base material 11 and the phosphoric acid chromate-treated surface of aluminum include polyester-based, polyethyleneimine-based, and polyether-based adhesives.
Various adhesives of cyanoacrylate type, urethane type, organic titanium type, polyether urethane type, epoxy type, polyester urethane type, imide type, isocyanate type, polyolefin type and silicone type can be used.

[0030]

EXAMPLES The packaging material for a lithium ion battery of the present invention will be described more specifically with reference to examples. In each of the chemical conversion treatments, an aqueous solution composed of a phenol resin, a chromium fluoride (3) compound, and phosphoric acid was applied as a treatment liquid by a roll coating method, and was baked under conditions where the film temperature was 180 ° C. or higher. The amount of chrome applied is 2mg
/ m ² (dry weight). In each of the following examples and comparative examples, the embossing type exterior body was a single-sided embossing type, and the shape of the concave portion (cavity) of the molding die was 30.
It was press-formed with a size of 50 mm x 50 mm and a depth of 6.0 mm, and the formability was evaluated. In each case, when the heat seal layer was made of polypropylene, the thickness of the seal was 50 μm on the seal portion of the tab of the lithium ion battery.
m, a film made of unsaturated carboxylic acid-grafted polypropylene, when the heat seal layer is polyethylene,
Sealing was performed with a 50 μm-thick film made of unsaturated carboxylic acid-grafted polyethylene interposed therebetween. [Example 1] Chemical conversion treatment was performed on both surfaces of aluminum 40 µm, and a stretched nylon film (thickness 25 µm) was adhered to one surface of the chemical conversion treatment by a dry lamination method. An acid-modified polypropylene emulsion is applied by a roll coating method, dried and baked at a temperature of 180 ° C.
A primary laminate was formed by thermally laminating a polypropylene film having a thickness of 0 μm. An erucic acid amide-based slip agent (0.2 mg / m 2) was applied to the surface of the stretched nylon as the base material layer by a gravure printing method using another apparatus.
² , using a 0.5% solution) to obtain Sample Example 1. Example 2 A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was adhered to one surface of the chemical conversion treatment by a dry lamination method. An emulsion of acid-modified polyethylene is applied by a roll coating method, dried and baked at a temperature of 160 ° C.
A linear low-density polyethylene film having a thickness of μm was thermally laminated to form a primary laminate. An erucic acid amide-based slip agent (0.2 m
g / m ² , using a 0.5% solution) to obtain Sample Example 1. Example 3 A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was bonded to one surface of the chemical conversion treatment by a dry lamination method. , Acid-modified polypropylene as adhesive resin (thickness 20μm),
Random polypropylene film (ethylene content 4
%, 30 μm) by sandwich lamination to obtain a primary laminate. After heating the primary laminate to a temperature equal to or higher than the softening point of the acid-modified polypropylene resin by hot air, the surface of the base material layer of the laminate is separated by a gravure reverse method using another device.
Sample 3 was obtained by coating with oleic amide (1.2 mg / m ² , using a 2.0% solution). Example 4 Chemical conversion treatment was performed on both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was adhered to one surface of the chemical conversion treatment by a dry lamination method. An acid-modified polyethylene was used as an adhesive resin (thickness: 20 μm), and a linear low-density polyethylene film (30 μm) was sandwich-laminated to form a primary laminate. After heating the primary laminate to a temperature higher than the softening point of the acid-modified ethylene resin by hot air, oleic acid amide random (8 mg / m ² , (A 10% solution was used) to obtain Sample Example 3. Example 5 A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was bonded to one surface of the chemical conversion treatment by a dry lamination method. A state in which the acid-modified polypropylene resin, which is the adhesive resin, is heated to a temperature higher than the softening point of the adhesive resin by far infrared rays and hot air, is used as a heat-sealing layer. %, 30 μm) by sandwich lamination to form a primary laminate. The primary layered product was erucic acid amide (0.2 mg / m ² , 0.2 mg / m ^{2) on} the innermost surface of the random polypropylene by a gravure reverse method using another device.
(5% solution used) to obtain Sample Example 1. [Example 6] A chemical conversion treatment was applied to both surfaces of aluminum 40 µm, and one surface of the chemical conversion treatment was applied to stretched nylon (thickness 25).
μm) by dry lamination, and then
A medium-density heat-sealable layer is formed by heating the surface of the acid-modified polyethylene resin, which is the adhesive resin, to a temperature higher than the softening point of the acid-modified polyethylene resin by the other surface far-infrared rays and the hot air. A polyethylene film (30 μm) is sandwich-laminated,
A primary laminate was formed. An erucic acid amide (0.1 m) was applied to the surface of the base layer of the primary laminate by a gravure reverse method.
g / m ² , using a 0.5% solution) to obtain Sample Example 2. [Example 7] Chemical conversion treatment was applied to both surfaces of aluminum 40 µm, and a stretched nylon film (thickness 25 µm) was bonded to one surface of the chemical conversion treatment by dry lamination, and then to the other surface of the chemical conversion-treated aluminum. , Acid-modified polypropylene as adhesive resin (thickness 20μm),
Random polypropylene film (ethylene content 4
%, 30 μm) by sandwich lamination to obtain a primary laminate. The primary laminate was heated to a temperature higher than the softening point of the acid-modified polypropylene resin by hot air. When the laminate film is embossed, a concave (cavity) molding size of 30 mm × 50 mm immediately before the mold is about 10 mm.
Oleic acid amide (0.5% solution)
Was partially sprayed to obtain Sample Example 7.

[Comparative Example 1] A chemical conversion treatment was applied to both surfaces of 40 μm of aluminum, and a stretched nylon film (25 μm in thickness) was bonded to one surface of the chemical conversion treatment by a dry lamination method. Was coated with an acid-modified polypropylene emulsion by a roll coating method, dried and baked at a temperature of 180 ° C., and a polypropylene film having a thickness of 30 μm was thermally laminated on the baked surface to form a primary laminate. The obtained laminate was used as Sample Comparative Example 1. [Comparative Example 2] A chemical conversion treatment was applied to both surfaces of aluminum 40 µm, and a stretched nylon film (thickness 25 µm) was bonded to one surface of the chemical conversion treatment by a dry lamination method, and then to the other surface of the chemical conversion-treated aluminum. An emulsion of acid-modified polyethylene is applied by a roll coating method, dried and baked at a temperature of 160 ° C.
A linear low-density polyethylene film having a thickness of μm was thermally laminated to form a primary laminate. The obtained laminate was designated as Sample Comparative Example 2. [Comparative Example 3] A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was adhered to one surface of the chemical conversion treatment by a dry lamination method, and then to the other surface of the chemical conversion treatment aluminum. , Acid-modified polypropylene as adhesive resin (thickness 20μm),
Random polypropylene film (ethylene content 4
%, 30 μm) by sandwich lamination to obtain a primary laminate. The primary layered product was coated with oleic acid amide (1.2 mg / m ² , 2.0% solution used) on the surface of the base material layer of the layered product by a gravure reverse method using another apparatus to obtain Sample Comparative Example 3. Was. [Comparative Example 4] A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and a stretched nylon film (thickness 25 μm) was bonded to one surface of the chemical conversion treatment by a dry lamination method, and then to the other surface of the chemical conversion-treated aluminum. A medium-density polyethylene film (30 μm) was sandwich-laminated with an acid-modified polyethylene as an adhesive resin (thickness: 20 μm) to form a primary laminate. The primary laminate was applied to the surface of the base material layer of the laminate by a separate apparatus by a gravure reverse method using amide oleate random (8 mg / m ² , 10 mg / m ² ,
% Solution was used) to obtain Sample Comparative Example 4. [Comparative Example 5] A chemical conversion treatment was applied to both sides of 40 μm aluminum, and a stretched nylon film (25 μm in thickness) was bonded to one surface of the chemical conversion treatment by a dry lamination method. A state in which the acid-modified polypropylene resin (adhesive resin) is heated to a temperature higher than the softening point of the adhesive resin by far-infrared rays and hot air is used. %, 30 μm) by sandwich lamination to form a primary laminate. The obtained laminate was designated as Sample Comparative Example 5. [Comparative Example 6] A chemical conversion treatment was applied to both surfaces of aluminum 40 μm, and one surface of the chemical conversion treatment was subjected to stretched nylon (thickness 25).
μm) by dry lamination, and then
When the surface is heated to a temperature higher than the softening point of the acid-modified polyethylene resin as the adhesive resin by the other surface far-infrared rays subjected to the chemical conversion treatment and the hot air, the acid-modified polyethylene resin (20 μm) is used as the adhesive resin to form a linear heat-sealing layer A low-density polyethylene film (30 μm) was sandwich-laminated to form a primary laminate. The obtained laminate was designated as Sample Comparative Example 6.

<Evaluation method> 1) Moldability The presence or absence of wrinkles, pinholes, film breakage, etc. was confirmed. 2) Delamination between base layer and aluminum layer Immediately after molding, heat seal at 190 ° C. for 5 seconds and 98 N / cm ² , and after leaving at 90 ° C. for 24 hours, delamination between aluminum and base layer. The presence or absence was checked. 3) Content resistance As a storage condition, each sample was stored in a thermostat at 60 ° C. and 90% RH for 7 days, and then the presence or absence of delamination between aluminum and the heat seal layer was confirmed. Contents: 3 g of a mixed solution of ethylene carbonate, diethyl carbonate, and dimethyl carbonate (1: 1: 1) so that the electrolytic solution becomes 1M LiPF ₆ .

<Results> In all of Examples 1 to 7,
During embossing, there was no occurrence of molding defects such as wrinkles and breakage of the film, and no delamination between the substrate and aluminum occurred. In addition, no delamination due to the contents was found. In Comparative Examples 1 and 2, pinholes occurred during molding in 10 to 20 samples out of 500 samples. However, delamination between the substrate and aluminum did not occur. In Comparative Examples 3 and 4, no molding failure occurred and no delamination between the base material and aluminum occurred, but all the delaminations caused by the resistant materials occurred in 500 samples.
In Comparative Examples 5 and 6, molding defects (pinholes) occurred in 30 to 40 of 500 samples. However, no delamination between the substrate and the aluminum and no delamination due to the content resistance occurred.

[0034]

The chemical conversion treatment applied to both surfaces of aluminum in the packaging material for lithium ion batteries of the present invention prevents the occurrence of delamination between the base material layer and aluminum during embossing and heat sealing. When the heat seal layer is formed by a sandwich lamination method or a co-extrusion lamination method, the electrolyte and moisture of the lithium ion battery are heated by heating during the formation of the laminate or by heating after the formation of the laminate. Can prevent corrosion of the aluminum surface due to hydrogen fluoride generated by the above reaction, thereby exhibiting a remarkable effect of preventing delamination of aluminum with the content-side layer. By coating a fatty acid amide-based slip agent on the outermost surface of the exterior body, the embossing property is good, and even if it is a non-slip layer made of stretched nylon or the like, the effect of stably forming can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a laminate in a packaging material for a lithium ion battery of the present invention, according to a lamination method;
(A) Thermal lamination and (b) Sandwich lamination.

FIG. 2 is a perspective view illustrating an embossed type exterior body of a lithium ion battery.

FIG. 3 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. 4 is a perspective view illustrating a pouch type exterior body of a lithium ion battery.

FIG. 5 is a perspective view for explaining a method of mounting an adhesive film in bonding a wrapping material for a lithium ion battery and a tab.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lithium-ion battery 2 Lithium-ion battery main body 3 Cell (power storage part) 4 Tab (electrode) 5 Outer body 6 Adhesive film (tab part) 7 Concave part 8 Side wall part 9 Seal part 10 Laminate (packing material for lithium-ion battery) DESCRIPTION OF SYMBOLS 11 Base material layer 12 Aluminum (barrier layer) 13 Heat seal layer 14 Chemical conversion treatment layer 15 Acid-modified polypropylene (coating) 16 Acid-modified polypropylene (extrusion) 17 Adhesive layer 18 Slip agent layer 20 Press molding part 21 Male type 22 Female type 23 cavity

Continuation of the front page (72) Inventor Kazuki Yamada 1-1-1 Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 3E067 AA24 AB42 AC01 BA10A BA33A BB25A BC02A BC07A CA05 CA17 CA24 EA09 FA01 FC01 GB20 GD07 3E086 AA02 AB01 AD05 BA04 BA13 BA15 BA24 BB02 BB20 BB35 BB41 BB49 BB52 CA31 5H011 AA02 AA09 CC02 CC06 DD03 DD09 DD13 DD21 KK04 5H029 AJ13 AJ14 AK02 AK05 AK08 AL08 AM12 C02 B07 AM02

Claims (9)

[Claims] 1. A laminate comprising at least a base material layer, an adhesive layer, a chemical conversion treatment layer 1, aluminum, a chemical conversion treatment layer 2, an acid-modified polyolefin layer, and a polyolefin layer, and at least a fatty acid amide on the surface of the base material layer. A packaging material for a lithium ion battery, characterized by being coated with a system slip agent. 2. The packaging material for a lithium ion battery according to claim 1, wherein the polyolefin layer is made of polypropylene. 3. The packaging material for a lithium ion battery according to claim 1, wherein the polyolefin layer is made of polyethylene. 4. The packaging material for a lithium ion battery according to claim 1, wherein the slip agent is erucic acid amide. 5. The packaging material for a lithium ion battery according to claim 1, wherein the slip agent is oleic amide. 6. After degreasing both sides of aluminum and providing a chemical conversion treatment layer, a base layer is provided on one side by a dry lamination method, and an acid-modified polyolefin emulsion is applied on the other side, dried and baked. A method for producing a packaging material for a lithium battery, comprising laminating a polyolefin film on the application surface by heat lamination to form a laminate, and coating at least the surface of the substrate layer of the laminate with a fatty acid amide slip agent. . 7. After degreasing both sides of aluminum and providing a chemical conversion treatment layer, a base layer is provided on one side by dry lamination, and a polyolefin film is sandwich-laminated on the other side using an acid-modified polyolefin as an adhesive resin layer. Heating the laminate thus obtained to a temperature equal to or higher than the softening point of the acid-modified polyolefin, and thereafter coating a fatty acid amide-based slip agent on at least the surface of the base material layer of the laminate. Manufacturing method of battery packaging material. 8. After degreasing both surfaces of aluminum and providing a chemical conversion treatment layer, a base layer is provided on one surface by a dry lamination method, and a polyolefin film is formed on the other surface by using an acid-modified polyolefin as an adhesive resin layer. In sandwich lamination, the surface temperature of aluminum, which is the extruded surface of the acid-modified polyolefin, is heated to a temperature equal to or higher than the softening point of the acid-modified polyolefin resin to form a laminate, and at least the surface of the substrate layer of the laminate A method for producing a packaging material for a lithium battery, characterized in that a fatty acid amide-based slip agent is coated on the material. 9. The method for producing a packaging material for a lithium ion battery according to claim 6, wherein the coating of the slip agent is performed immediately before embossing.