JP2006066113A - Laminated material and battery exterior material using the laminated material - Google Patents

Abstract

The present invention has a high degree of barrier properties, resistance to electrolytes and acids, good thermal adhesiveness, and suitability for bag-making, as well as moldability to tray-like containers. A laminated material that can be suitably used for an exterior material such as a lithium polymer battery and a battery exterior material using the laminated material are provided.
At least a suspension coating solution in which a modified polypropylene is dispersed in a solid state in an organic solvent is applied onto the aluminum foil of a base material in which an aluminum foil is laminated on one side of a plastic film. A heat-dried modified polypropylene coating layer 6 that functions as an adhesive layer capable of thermal lamination is provided, and the sealant film layer 5 is laminated by heating and pressure bonding through the modified polypropylene coating layer 6 by thermal lamination. The laminated material 10 is characterized in that a rough surface 5a is formed on the surface of the sealant film layer 5, and a battery exterior material using the laminated material 10.
[Selection] Figure 1

Description

  The present invention relates to a laminated material excellent in adhesion with controlled static friction coefficient and dynamic friction coefficient, and more particularly, it is thin, light weight, highly water vapor and other barrier properties, and electrolyte solution In addition to excellent heat resistance against heat and acids, heat resistance during heat sealing, etc., as well as good thermal adhesiveness and bag-formability to form bags, it also has moldability to tray-like containers, etc. The present invention relates to a laminated material that can be suitably used for an exterior material such as a lithium polymer battery having a severe demand for performance, and a battery exterior material using the laminated material.

  Conventionally, in most cases, a metal container has been used as a container serving as a battery exterior material. However, along with the development and widespread use of various electronic devices such as notebook computers and mobile phones, their thickness and weight have been reduced, and the batteries used for these have been made as light as possible and used. Thinning and weight reduction are demanded so that battery space in equipment can be reduced as much as possible.

  In order to meet such demands, for example, various polymer batteries, in which polymer materials are introduced into battery electrodes, electrolytes, etc., and are made thinner and lighter in the form of sheets have been researched and developed. As a typical example of such a polymer battery, for example, a lithium polymer battery can be cited. These polymer batteries are thinned by using a laminated material for the exterior material in order to reduce the thickness of the battery itself. The method to be taken is taken.

  When a laminated material is used for the outer packaging material of a polymer battery, the form and method of use are, for example, a three-sided seal type, a four-sided seal type, a pillow pouch type, etc. In addition, the battery constituent material is housed inside, the electrode terminal is extended from the inside to the outside through the opening, and the opening is sealed by thermal bonding, or a battery is formed around the laminated material Molded into a tray with a flange, the battery material is stored in the recess, the electrode terminal is extended to the outside, the upper part is covered with a cover of laminated material, and the flange is thermally bonded There is a method of sealing and forming a battery.

  The laminated material used for the battery outer packaging material has lightness and thinness, resistance to various mechanical strengths and electrolytes, water vapor and other barrier properties, heat sealing properties, and heat with the electrode terminals. Various performances such as adhesiveness are required. In particular, in the case of forming and using the flanged tray, the moldability is also required. In addition, when the battery is a lithium polymer battery or the like, when moisture enters the inside, it reacts with the electrolyte component to generate hydrogen fluoride, which invades the inner surface of the metal foil layer through the thermal adhesive resin layer. The adhesive surface may be peeled off. Therefore, the laminated material requires a high degree of moisture resistance.

  The laminated material used for the battery outer packaging material, depending on whether the shape of the outer packaging is a bag form by bag making or a tray container form that has been molded, the material and thickness of the laminated material Although it is necessary to change a little, in order to reduce the thickness of the laminated material as much as possible, it is based on the structure in which the base material layer, the metal foil layer, and the heat-adhesive resin layer are laminated in order from the outside. Further, it is possible to adopt a configuration in which an intermediate layer or the like is added to this.

For example, a biaxially stretched nylon film excellent in various mechanical strengths can be used for the base material layer, an aluminum foil is used for the metal foil layer, and a heat-adhesive resin layer is used for the heat-adhesive resin layer. For example, a single layer of polyethylene, polypropylene, acid-modified polyethylene, acid-modified polypropylene, or the like, or a composite layer in which two or more are appropriately laminated can be used.

  However, even when the laminated material is configured as described above, when the laminated material is drawn into a tray shape with a mold such as a male mold and a female mold, the surface of the outer base film constituting the outermost layer and the innermost layer is used. There is a problem that the coefficient of friction is high, the slippage between the outer surface of the laminated material and the male mold and the female mold is poor, and the molding cannot be performed uniformly and smoothly and the moldability is poor. In addition, when the aluminum foil of the metal foil layer is left as it is, when battery contents such as lithium polymer batteries are stored and packaged for a long period of time, there is a problem that the adhesive strength between the aluminum foil and the sealant layer decreases and delamination occurs. It was.

  The present invention has been made to solve the above-described problems, and its object is to have a thin thickness, a low weight, and a high degree of water vapor and other barrier properties. In addition to excellent resistance to electrolytes and acids, heat resistance against heat during heat sealing, etc., it also has good heat adhesion and suitability for bag-making, as well as moldability to tray-like containers. An object of the present invention is to provide a laminated material that can be suitably used for an exterior material such as a lithium polymer battery, which has various requirements for various performances, and a battery exterior material using the laminated material.

In order to achieve the above object, that is, the invention according to claim 1,
At least a laminated material obtained by heating and press-bonding a sealant film layer by thermal lamination on the aluminum foil of a base material in which an aluminum foil is laminated on one side of a plastic film,
On the aluminum foil, a modified polypropylene coating layer that functions as an adhesive layer capable of thermal lamination is provided by applying a suspension coating solution in which a modified polypropylene is dispersed in a solid state in an organic solvent, followed by heating and drying. The laminate material is characterized in that a sealant film layer is laminated by heating and pressure bonding by thermal lamination through the modified polypropylene coating layer, and a rough surface is formed on the surface of the sealant film layer.

The invention according to claim 2
The surface forming the rough surface of the sealant film layer has a static friction coefficient of 0.20 or less and a dynamic friction coefficient of 0.15 or less in accordance with JIS K7125 “Plastic and Sheet Friction Test Method”. The laminated material according to claim 1, wherein:

The invention according to claim 3
The static friction coefficient according to JIS K7125 “Plastic and Sheet Friction Test Method” on the surface of the plastic film is 0.25 or less, and the dynamic friction coefficient is 0.20 or less. 2 is a laminated material.

The invention according to claim 4
The laminated material according to claim 1, wherein the plastic film is a biaxially stretched nylon film.

The invention according to claim 5
The sealant film constituting the sealant film layer is an unstretched polypropylene film, and the laminated material according to any one of claims 1 to 4.

The invention according to claim 6
6. The laminated material according to claim 5, wherein the unstretched polypropylene film is a multilayer coextruded film having a block polypropylene as a core layer and a surface made of random propylene.

The invention according to claim 7 provides:
The rough surface formed on the surface of the sealant film layer is a rough surface formed by heating and pressure transfer using an embossing roll mold having a pair of rough surfaces. It is a laminated material of any one of 1-6.

The invention according to claim 8 provides:
The laminated material according to any one of claims 1 to 7, wherein the aluminum foil is subjected to a boehmite treatment.

The invention according to claim 9 is:
It is a battery exterior material using the laminated material of any one of Claims 1-8.

<Action>
The laminated material of the present invention, at least, on the aluminum foil of the base material laminated with an aluminum foil on one side of a plastic film, a suspension coating solution in which a modified polypropylene is dispersed in a solid state in an organic solvent, A heat-dried modified polypropylene coating layer that functions as a heat-laminable adhesive is provided, and the sealant film layer is laminated by thermocompression bonding through the modified polypropylene coating layer by the thermal lamination method, and then the innermost layer of the laminated material A rough surface is formed on the surface of the sealant film layer, and the surface has a static friction coefficient of 0.20 or less in accordance with JIS K7125 “Plastic and Sheet Friction Test Method”, and The dynamic friction coefficient is controlled to 0.15 or less, the static friction coefficient is 0.25 or less, and the dynamic friction Conventionally, a resin mainly composed of a modified polypropylene resin when laminating a sealant film layer on an aluminum foil has been used by constituting the outermost layer of the laminated material having a coefficient of 0.20 or less. In the conventional extrusion lamination method, the surface of the sealant film is melted by high-temperature heat treatment for the purpose of improving adhesion (electrolyte resistance), and the laminated material is drawn into a tray with a mold such as a male mold and a female mold. In the case where the outermost base layer film constituting the outermost layer and the innermost layer has a high coefficient of friction, the slippage between the outer surface of the laminated material and the male mold and the female mold is poor, and the molding can be performed uniformly and smoothly. Problems such as inability to form and inferior formability, and the aluminum foil of the metal foil layer stored and packaged battery contents such as lithium polymer batteries for a long time. If the adhesive strength of the aluminum foil and the sealant layers is reduced, it is possible to solve problems such as delamination occurs.

  According to the present invention, it is thin and light in weight, has a high degree of water vapor and other barrier properties, has excellent resistance to electrolytes and acids, etc., and excellent heat resistance to heat during heat sealing, etc. Laminate that can be used suitably for exterior materials such as lithium polymer batteries, which are required to have various performances. It is providing the exterior material for batteries using material and its laminated material.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment as an example of the invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the configuration of the laminated material of the present invention. FIG. 2 is an explanatory view for explaining an example of a laminating method of the laminating material of the present invention and a method of forming a rough surface on the surface of the sealant film layer.

  As shown in FIG. 1, a laminated material 10 according to an embodiment of the present invention includes an aluminum foil 2 of a base material 4 in which an aluminum foil 2 is laminated on one side of a plastic film 1 via an adhesive layer 3 for dry lamination. The surface is subjected to a boehmite treatment to have a boehmite treatment layer 2a. The boehmite-treated layer 2a of the aluminum foil 2 of the substrate 4 and the sealant layer 3 are laminated by heating and pressure bonding by a thermal lamination method through the modified polypropylene coating layer 6, and the surface of the sealant layer 3 is rough. The surface 5a is formed.

  First, the material which comprises the laminated material of this invention is demonstrated below. As the plastic film 1 used in the present invention, a biaxially stretched nylon or polyester film having a high elastic modulus is used, and a biaxially stretched nylon film is particularly preferable. A plastic film having a static friction coefficient of 0.25 or less and a dynamic friction coefficient of 0.20 or less in accordance with JIS K7125 “Plastic and Sheet Friction Test Method” is used.

  As an example of a method for maintaining the static friction coefficient of the plastic film 1 at 0.25 or less and the dynamic friction coefficient at 0.20 or less, a lubricant can be used. This lubricant is used for imparting external lubricity. For example, in addition to lubricants such as ester, alcohol, fatty acid, stearate, fatty acid amide, and hydrocarbon, silicone oil, etc. Can be used. Among these, fatty acid amide type lubricants such as stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, or straight silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and amino modification and epoxy modification A reactive silicone oil such as carboxyl-modified can be preferably used. For example, when silicone oil is added, the addition amount is suitably in the range of 0.1 to 20 parts by weight of silicone oil with respect to 100 parts by weight of the resin of the plastic film 1, so that the static friction coefficient is 0. .25 or less and the coefficient of dynamic friction can be 0.20 or less.

Specific examples of nylon films include polycaproamide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-9-aminononanoic acid (nylon 9), polyundecanamide (nylon 11), polylaurin lactam. (Nylon 12), polyethylenediamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6), polyhexamethylenediadipamide (nylon 6,6), polyhexamethylene sebacamide ( Nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8,6), polydecamethylene adipamide (nylon 10,6), polydecamethylene sebacamide (Nylon 10,10), polydodecamethylene dodecamide (nylon 12,12 , Poly-m-xylylene azide consisting adipamide (MXD6) and the like biaxially oriented nylon film (ONy) and the like.

  Specific examples of the polyester film include biaxially stretched polyester films such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymer polyester, and polycarbonate.

The aluminum foil 2 used in the present invention needs to have a thickness of 20 to 80 μm in order to ensure workability and prevent oxygen and moisture from entering the case. When the thickness is less than 20 μm, the aluminum foil is likely to break during press molding, and even when it does not break, pinholes and the like are liable to occur, which increases the risk of oxygen and moisture intrusion.
On the other hand, when the thickness exceeds 80 μm, neither the effect of improving the fracture during molding nor the effect of preventing the occurrence of pinholes is particularly improved, so it is desirable to avoid the increase in the total thickness of the packaging material and the increase in weight.

  As the material of the aluminum foil, an aluminum-iron alloy O material (soft material) is used. It is desirable that the iron content is 0.3 to 9.0%, preferably 0.7 to 2.0%. When the iron content is less than 0.3%, effects such as prevention of pinholes and improvement of embossing formability are not observed, and when the iron content of the aluminum exceeds 9.0% , The flexibility as aluminum is hindered, and the bag-making property is deteriorated as a laminate. In addition, aluminum produced by cold rolling changes its flexibility, waist strength and hardness under annealing (so-called annealing treatment) conditions, but aluminum is slightly more than the so-called hard-treated product that is not annealed. Alternatively, flexible aluminum that has been completely annealed is preferred. What is necessary is just to select suitably the softness | flexibility of the said aluminum, the intensity | strength of hardness, and the degree of hardness, ie, the conditions of annealing, according to workability (tray shaping | molding, embossing shaping | molding). For example, in order to prevent wrinkles and pinholes during tray molding and emboss molding, it is desirable to use annealed flexible aluminum according to the degree of molding.

  The thickness is preferably in the range of 20 to 80 μm in order to ensure processability and prevent oxygen and moisture from entering the case. When the thickness is less than 20 μm, the aluminum foil easily breaks during tray press molding, and even when it does not break, pinholes and the like are liable to occur, which increases the risk of oxygen and moisture intrusion. On the other hand, when the thickness exceeds 80 μm, the effect of improving the fracture during molding and the effect of preventing the occurrence of pinholes are not particularly improved. Therefore, the total thickness of the laminated material is simply increased and only the weight is increased. It is desirable.

  When the laminate material of the present invention is used as a battery case exterior material such as a lithium battery, the electrolyte does not cause a decrease in the laminate strength between the aluminum foil and the sealant layer. In order not to cause peeling from the aluminum foil layer, the aluminum foil is preferably subjected to a hot water modification treatment. As the treated water for treating the metal surface, tap water, deionized water, distilled water, or distilled water distilled after deionization can be used. In particular, deionized distilled water is preferred, and its index It is preferable to use water having an electric conductivity of 1 μS / cm or less. In addition, it is more preferable to add 0.1 to 1% by weight of alkali such as amines such as ammonia and triethanolamine to these treated waters. As hydrothermal modification treatment of aluminum foil, various hydrated oxide layers are formed depending on the treatment temperature. A particularly preferable treatment temperature is preferably conditions under which boehmite is formed as a hydrated oxide, and it is better to perform hydrothermal denaturation treatment in the range of 80 to 100 ° C., more preferably 80 to 100 ° C. under normal pressure. In addition, the case where a hot water modification | denaturation process is applied to aluminum foil is called a boehmite process.

  As described above, using aluminum foil that has been subjected to hydrothermal modification treatment such as boehmite treatment does not reduce the laminate strength between the aluminum foil and the sealant layer due to the electrolyte of lithium batteries, etc. Even if it performs, peeling with an outermost layer and an aluminum foil layer is not seen, Furthermore, it uses suitably as battery exterior materials, such as a lithium battery with strong adhesion.

The sealant layer 5 used in the present invention is laminated to form a package. The sealant layer 5 is an adhesive thermoplastic resin that can be heat-sealed, and may be any material that can be melted by heat and fused to each other. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (Linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene- Propylene copolymer,
An acid-modified polyolefin resin obtained by modifying a polyolefin resin such as methylpentene polymer, polyethylene or polypropylene with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid or the like. Other resins can be used. The thickness is appropriately determined according to the purpose, but is generally in the range of 30 to 110 μm.

  As the sealant layer 5 used in the present invention, an unstretched polypropylene film is particularly preferably used. Among them, a multilayer coextruded film having a block polypropylene as a core layer and a surface made of random propylene is preferably used.

  Next, a method for laminating the laminated material of the present invention will be described below. The base material 4 in which the aluminum foil 2 is laminated on one side of the plastic film 1 is laminated with the plastic film 1 and the aluminum foil 2 through the adhesive layer 3.

As an adhesive constituting the adhesive layer 3 and a laminating method, a laminating method by a dry lamination method using an adhesive for dry lamination is preferable. As a dry lamination adhesive, a commonly used two-component curable urethane adhesive can be used, and as a coating method, it can be applied by a gravure coating method, a roll coating method or the like. The coating amount is preferably in the range of 1 to 5 g / m ² (dry state).

  On the other hand, a method for laminating the sealant layer 5 on the boehmite-treated surface 2a of the aluminum foil 2 of the substrate 4 in which the aluminum foil 2 is laminated on one side of the plastic film 1 constituting the laminated material of the present invention, and the surface of the sealant layer The rough surface is formed by applying a heat-laminated modified polypropylene coating layer on the boehmite-treated surface 2a of the aluminum foil 2, and laminating the sealant film layer 5 by heating and pressure bonding.

  The above-mentioned modified polypropylene coating layer 6 used in the present invention is an adhesive layer capable of thermal lamination, which is obtained by applying a suspension coating solution in which a modified polypropylene is dispersed in an organic solvent in a solid state, followed by heating and drying. It is a modified polypropylene coating layer that functions and can be heat-laminated by coating by a gravure coating method, a roll coating method or the like.

  As the above-mentioned modified polypropylene used in the present invention, for example, a modified polypropylene partially or entirely graft-modified with an unsaturated carboxylic acid or an anhydride thereof is used. Specifically, it is a graft copolymer obtained by graft copolymerizing unsaturated carboxylic acid or its anhydride with all or part of polypropylene constituting the main skeleton. The polypropylene constituting the main skeleton of the modified polypropylene is a homopolymer of propylene, or a block copolymer or a random copolymer made of propylene and another monomer. Examples of other monomers include ethylene, 1-butene, isobutene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 2-methyl-1-pentene, 1-heptene and the like can be mentioned, and these may include one or a combination of two or more in polypropylene. The content of other monomers in the polypropylene is usually 10% by weight or less. Among these, a propylene homopolymer, an ethylene-propylene block copolymer, and an ethylene-propylene random copolymer are preferable from the viewpoint of cost.

Examples of the unsaturated carboxylic acid or its anhydride (hereinafter referred to as “graft monomer”) to be graft copolymerized with the modified polypropylene include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, maleic acid, and fumaric acid. , Unsaturated dicarboxylic acids such as itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, nadic acid, methyl nadic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, maleic anhydride, itaconic anhydride,
Examples thereof include unsaturated dicarboxylic anhydrides such as citraconic anhydride, allyl succinic anhydride, glutaconic anhydride, nadic anhydride, methyl nadic anhydride, tetrahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. The modified polypropylene may contain one kind of these graft monomers or a combination of two or more kinds. Among these, maleic acid, maleic anhydride, nadic acid, and nadic anhydride are preferable from the viewpoints of cost and physical properties.

  The content of the graft monomer in the modified polypropylene is 0.1 to 10% by weight in terms of obtaining an adhesive composition having excellent adhesion to the metal foil and adhesion to the film, and this range. However, if the amount is too large, the solubility in a solvent may be deteriorated. If the amount is too small, the adhesiveness and heat resistance may be lowered. Therefore, the amount is preferably 0.5 to 5% by weight.

  Furthermore, this modified polypropylene is sufficiently agglomerated to exhibit excellent adhesiveness, and exhibits sufficient fluidity when dissolved to form a smooth coating film or adhesive layer to exhibit excellent adhesiveness. In terms of obtaining a composition, the intrinsic viscosity [η] is 0.3 to 1.5 dl / g. In order to obtain particularly excellent adhesion and heat resistance, the intrinsic viscosity [η] is 0. Those having a molecular weight of 5-1.2 dl / g are preferred. In the present invention, the intrinsic viscosity [η] is a value measured in 135 ° C. decalin.

  Examples of the organic solvent as a dispersion medium for dispersing the modified polypropylene in a solid state include aromatic hydrocarbons, alcohols, ketones, ethers, acid anhydrides, esters, cellosolves, and the like. . Among these, toluene, o-xylene, m-xylene, p-xylene, mesitylene, cumene, p-cymene, methanol, ethanol, isopropanol, n-butanol, water, diethyl ether, dibutyl ether, dioxane, acetone, methyl ethyl ketone, Methyl isobutyl ketone, acetic anhydride, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, methyl cellosolve, and ethyl cellosolve are preferred, and these may be used alone or in combination of two or more. Further, the content of the organic solvent in the resin dispersion is not particularly limited as long as the modified polypropylene can be dispersed.

  The modified polypropylene is preferably dispersed in the organic solvent in a solid state, and the dispersed particles made of the modified polypropylene preferably have a particle size of 100 μm or less, and are particularly excellent in the smoothness of the coating film. For use as a membrane, those having a thickness of 30 μm or less are preferred.

  The temperature for bonding through the modified polypropylene coating layer 6 used in the present invention is usually about 170 to 200 ° C.

In the same process of laminating the base material 4 and the sealant film layer 5 by the laminating method described above, a rough surface 5a is formed by subsequently heat-transferring using an embossing roll mold having a pair of rough surfaces formed on the surface of the sealant layer. The laminated material of the present invention having the structure shown in FIG. 1 is obtained. FIG. 2 is a schematic diagram for explaining an example of a method for laminating the laminated material of the present invention having the configuration shown in FIG. 1 and a manufacturing process for forming a rough surface on the surface of the sealant layer. A sealant film 5 made of an unstretched polypropylene (CPP) film or the like is unwound from a first unwinding roll 20, while an aluminum foil 2 is laminated on one surface of a plastic film 1 made of a biaxially stretched nylon film or the like. A base material 7 formed by applying a modified polypropylene coating layer 6 to the treated surface 2a of which the surface of the foil has been subjected to boehmite treatment and drying by heating was produced in a separate process. The modified polypropylene coating layer 6 formed on the treated surface 2a of the aluminum foil 2 of the base material 7 between the pair of thermal drums 23 and the thermal drum nip rolls 22 and the CPP film, etc. After bonding a sealant film 5 made of A heating device (heater) 24 for heating the substrate is provided between the roll mold 26 and the surface of the sealant film 5 made of the CPP film of the laminate 8 is heated by the heating device (heater) 24 to be in a molten state. The rough surface 5a is formed on the surface of the sealant film 5 by pressure-transferring the rough surface of the embossing roll mold 26 between the embossing roll mold 26 and the embossing nip roll 25 having a rough surface on the surface 5 of the sealant film. The laminated material 10 can be wound and manufactured with a winding roll 27.

  The static friction coefficient of the surface forming the rough surface of the sealant film layer 5 in the laminated material of the present invention is 0.20 or less in accordance with JIS K7125 “Plastic and Sheet Friction Test Method”, and the dynamic friction coefficient The roughness of the rough surface formed on the embossing roll mold is controlled so as to be 0.15 or less, and a rough surface that satisfies the values of the static friction coefficient and the dynamic friction coefficient is formed on the surface of the sealant film layer. be able to.

  Since the laminated material of the present invention has the above-described configuration, when the laminated material is used for the exterior material of the lithium polymer battery, as the form and usage, for example, the laminated material is a three-way seal. Formed in a bag shape with one end open in the form, four-side seal type, pillow pouch type, etc., and the battery constituent material is housed inside, and the electrode terminal is extended from the inside to the outside through the opening, and the opening The battery is sealed by thermal bonding to form a battery, or the laminated material is formed into a tray with a flange around it, and the battery components are housed in the recess and the electrode terminals are extended outward. In addition, the upper part is covered with a cover material of a laminated material, and is heat-adhered and sealed at a flange part, and is suitably used as a tray-like exterior material as well as a bag shape such as a method of forming a battery.

  An example of a battery case using the laminated material of the present invention as a battery case exterior material will be described. FIG. 3 is a schematic cross-sectional view showing an example of a battery case container produced using the laminated material of the present invention. The battery case container 30 shown in FIG. 3 includes a flanged tray-like container body 31 formed by press molding, and a flat lid member 33 placed on the tray-like container body 31. It is formed of the laminated material 10 of the present invention having the configuration as shown.

  In such a battery case container 30, the constituent material of the battery is mounted in the molding concave portion of the tray-shaped container body 31 with flange, the electrode terminal is extended from the inside to the outside, and then the lid 33 is covered on the upper part thereof. A thin battery can be manufactured by thermally bonding and sealing the two at the flange portion 32.

  FIG. 4 is a schematic cross-sectional view showing another example of a battery case container manufactured using the laminated material of the present invention. The battery case container 40 shown in FIG. 4 is the battery case container shown in FIG. In the configuration of 30, the lid member is also configured using a flanged tray-like container 31 similar to the lower flanged tray-like container body 31. In the case of adopting such a configuration, since the molded concave portions are formed in the flanged tray-like container 31 on both the lids, the depth of each molded concave portion can be reduced to ½.

  As shown in FIG. 5, the above press molding (drawing) sandwiches a laminated material 10 for forming a battery case container between a convex mold 50 having a convex surface and a concave mold 60 having a concave surface. This refers to the process of forming by pressing both molds. Here, R is the radius of curvature of the corner of the mold, and H is the depth of the stop. For battery case containers, it is desirable to make the radius of curvature R as small as possible in order to increase the effective volume of the molded container, preferably 2 mm or less, and the drawing depth H is required to be 3 mm or more. There is no particular upper limit to the aperture depth, but in practice it is limited to about 20 mm. Further, the total thickness of the laminated material 10 is 0.3 mm or less, desirably 0.2 mm or less.

The laminate material 10 described above is drawn with the sealant film layer side facing the convex mold 50 and the plastic film 1 side facing the concave mold 60. In order to secure a space for storing the electrode and the electrolyte for improving the battery energy density, it is necessary to set the drawing depth H to 3 mm or more. In order to perform such deep drawing without tearing the laminated material 10, according to the present invention, at least an organic solvent is formed on the aluminum foil of the base material in which the aluminum foil is laminated on one side of the plastic film. A suspension coating solution in which a modified polypropylene is dispersed in a solid state is applied to the substrate, and a modified polypropylene coating layer functioning as an adhesive capable of thermal lamination is provided by heating and drying, and heat is passed through the modified polypropylene coating layer. After the sealant film layer is laminated by thermocompression bonding by the lamination method, a rough surface is formed on the surface of the sealant film layer which is the innermost layer of the laminated material. JIS K7125 “Plastics and Sheets on the surface of the rough surface The coefficient of static friction is 0.20 or less and the coefficient of dynamic friction is 0.1. It is necessary to control it to 5 or less, and to make the plastic film that is the outermost layer of the laminated material having a static friction coefficient of 0.25 or less and a dynamic friction coefficient of 0.20 or less.

  Hereinafter, specific examples of the laminated material of the present invention will be described.

  Using the materials shown below, the laminated material of the present invention having the configuration shown in FIG. 1 was prepared. The composition of the laminated material is as follows: ONy film layer (1) / adhesive layer (3) / AL foil (2) | (boehmite treated surface) (2a) / modified PP coating layer (6) / CPP (5) | Embossed rough surface) (5a). In the sealant processing, after applying “Moleprime MP-8APCJ” as the modified PP coating layer (6), CPP (5) was laminated by a thermal lamination method.

<Materials used>
Plastic film layer 1: Biaxially stretched nylon film (ONy) with a thickness of 25 μm (“Unilon G-100” manufactured by Idemitsu)
Aluminum foil layer 2: 40 μm thick aluminum foil (AL foil) (“CE8079” manufactured by Toyo Aluminum Co., Ltd.)
-Adhesive layer 3: Adhesive for dry lamination (“AD502” manufactured by Toyo Morton Co., Ltd., coating amount: 3 g / m ² )
Sealant layer (5): 30 μm thick unstretched polypropylene (CPP) (“Aroma ET20” manufactured by Showa Denko KK)
Modified polypropylene coating layer (modified PP coating layer) (6): “Morprime MP-8APCJ” manufactured by Toyo Morton Co., Ltd., coating amount 4 g / m ² )

  As a comparative example for comparing the performance with the laminated material of the present invention obtained in Example 1, the sealant processing in Example 1 was carried out using a modified polypropylene resin (SPP) having a thickness of 15 μm instead of the modified PP coating layer (6). A laminate material having the following constitution was prepared in the same manner as in Example 1 except that heat treatment was performed after the extrusion aging of and no embossing was performed on the CPP surface. ONy film layer (1) / adhesive layer (3) / AL foil (2) | (boehmite treated surface) (2a) / SPP layer / CPP (5)

As a comparative example for comparing the performance with the laminated material of the present invention obtained in Example 1, a modified polypropylene resin (SPP) instead of the modified PP coating layer (6) was subjected to a heat treatment after extrusion aging with a thickness of 15 μm. A laminated material having the following constitution was prepared in the same manner as in Example 1 except that the CPP surface was not embossed.
ONy film layer (1) / adhesive layer (3) / AL foil (2) | (boehmite treated surface) (2a) / SPP layer / CPP (5)

As a comparative example for comparing the performance with the laminated material of the present invention obtained in Example 1, the laminated material having the following constitution was the same as in Example 1 except that the CPP surface in Example 1 was not embossed. It was created.
ONy film layer (1) / adhesive layer (3) / AL foil (2) | (boehmite treated surface) (2a) / modified PP coating layer (6) / CPP (5)
The laminated materials obtained in Examples 1 to 4 were evaluated for slipperiness, moldability, and electrolyte resistance based on the evaluation methods shown below. The results are shown in Table 1.

<Slipperiness>
The static friction coefficient and the dynamic friction coefficient were measured using an iron sliding piece conforming to JIS K7125 “Plastic and Sheet Friction Test Method”.

<Moldability>
A tray-shaped molded product was prepared using a molded prototype [7 mm depth (H), 1.3 mm (R) × 4C], and particularly, the presence or absence of pinholes and cracks in the aluminum foil was confirmed. In the table, ○ indicates no occurrence of pinholes or cracks. In x, occurrence of pinholes and cracks was observed. It shows that.

<Electrolyte resistance>
A test piece (15 mm width × 50 mm) was prepared by adding a fluorine-containing lithium salt (LiPF 6) to a mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 1/1 as an electrolytic solution composition to 1.5 N. ) Was measured, and the laminate strength between the aluminum foil and the sealant film layer constituting the laminated material after storage at 85 ° C. for 1 week was measured, and the peeled state at that time was confirmed. The conditions for measuring the laminate strength are as follows.
(T-type peel test)
Tensile speed: 300 mm / min
Test piece: 15mm width

  From Table 1, the laminated material of the present invention obtained in Example 1 is obtained by dispersing modified polypropylene in an organic solvent in a solid state on at least an aluminum foil of a base material in which an aluminum foil is laminated on one side of a plastic film. A modified polypropylene coating layer that functions as an adhesive that can be thermally laminated is applied by applying the suspension coating solution and heat-dried, and heat-pressed by the thermal lamination method through the modified polypropylene coating layer to form a sealant film After laminating the layers, a rough surface is formed on the surface of the sealant film layer that is the innermost layer of the laminated material, and the static friction of the surface of the rough surface conforming to JIS K7125 “Plastic and sheet friction test method” The coefficient is controlled to 0.20 or less, the dynamic friction coefficient is controlled to 0.15 or less, and the static friction coefficient is 0. A 25 or less, and since the dynamic friction coefficient of a structure consisting of the plastic film as the outermost layer of 0.20 or less of a laminated material, moldability, it is excellent in all respects, such as laminate strength. On the other hand, the laminate material obtained in Example 2 as a comparative example for comparing performance with the laminate material of the present invention has a problem in formability due to the occurrence of pinholes / cracks in the aluminum foil. . Further, the laminated material obtained in Example 3 as a comparative example had a problem of laminate strength due to partial peeling at the interface between the aluminum foil layer and the sealant film layer. Further, the laminated material obtained in Example 4 as a comparative example had a problem in formability due to the occurrence of pinholes / cracks in the aluminum foil as in the laminated material obtained in Example 2.

It is sectional drawing which shows an example of a structure of the laminated material of this invention. It is explanatory drawing explaining the lamination | stacking method of the laminated material of this invention, and the method of forming an embossing rough surface in the sealant layer surface. It is sectional drawing which shows an example of the tray-shaped battery case container manufactured using the laminated material of this invention. It is sectional drawing which shows the other example of the tray-shaped battery case container manufactured using the laminated material of this invention. It is explanatory drawing explaining the drawing press molding as an example which shape | molds the tray-shaped battery case container in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic film layer 2 ... Aluminum foil layer 2a ... Boehmite processing layer 3 ... Adhesive layer 4, 7, 8 ... Laminated base material 5 ... Sealant layer 5a ... Embossing Rough surface 6 ... modified polypropylene coating layer 10 ... laminated material 20 of the present invention ... first unwinding roll 21 ... second unwinding roll 22 ... thermal drum nip roll 23 ... Thermal drum 24 ... Heating device (heater)
25 ... Embossing nip roll 26 ... Embossing die roll 27 ... Winding rolls 30, 40 ... Tray-like battery case container 31 with flange ... Tray-like battery case container body 32 ... Flange 33 ... Lid 50 ... Convex die 60 ... Concave die R ... Radius of curvature H ... Depth

Claims (9)

At least a laminated material obtained by heating and press-bonding a sealant film layer by thermal lamination on the aluminum foil of a base material in which an aluminum foil is laminated on one side of a plastic film,
On the aluminum foil, a modified polypropylene coating layer that functions as an adhesive layer capable of thermal lamination is provided by applying a suspension coating solution in which a modified polypropylene is dispersed in a solid state in an organic solvent, followed by heating and drying. A laminated material characterized in that a sealant film layer is laminated by heating and pressure bonding by thermal lamination through the modified polypropylene coating layer, and a rough surface is formed on the surface of the sealant film layer.   The surface forming the rough surface of the sealant film layer has a static friction coefficient of 0.20 or less and a dynamic friction coefficient of 0.15 or less in accordance with JIS K7125 “Plastic and Sheet Friction Test Method”. The laminated material according to claim 1, wherein the laminated material is provided.   The static friction coefficient according to JIS K7125 “Plastic and Sheet Friction Test Method” on the surface of the plastic film is 0.25 or less, and the dynamic friction coefficient is 0.20 or less. The laminated material according to 2.   The laminated material according to any one of claims 1 to 3, wherein the plastic film is a biaxially stretched nylon film.   The laminate material according to any one of claims 1 to 4, wherein the sealant film constituting the sealant film layer is an unstretched polypropylene film.   6. The laminated material according to claim 5, wherein the unstretched polypropylene film is a multilayer coextruded film having a block polypropylene as a core layer and a surface made of random propylene.   The rough surface formed on the surface of the sealant film layer is a rough surface formed by heating and pressure transfer using an embossing roll mold having a pair of rough surfaces. The laminated material according to any one of 1 to 6.   The laminated material according to any one of claims 1 to 7, wherein the aluminum foil is subjected to a boehmite treatment.   The battery cladding | exterior_material using the laminated material of any one of Claims 1-8.

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