JP2001260275A - Laminated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated body which is excellent in resistance to a solvent of a high polarity and corrosive substance. SOLUTION: In a laminated body provided by laminating a polymer film on at least one side face of a metal thin film, the metal thin film and the polymer film are laminated via an adhesive layer comprising a polyolefin based elastomer which is soluble in an organic solvent and has a polar group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate, and more particularly to a laminate suitable for use as an exterior material for enclosing a highly polar solvent or corrosive contents and shielding the same from the outside atmosphere. .

[0002]

2. Description of the Related Art In a laminate used for various packaging materials, a thin metal film such as aluminum is used for leakage of contents, blocking of oxidizing gases such as oxygen, nitrogen oxides, sulfur oxides, and ozone. The laminated structure is taken. At that time, various polymer films are laminated with the metal thin film in order to oxidize and corrode the metal thin film, to impart post-processability, to impart design properties, and to reinforce the metal thin film.

[0003] The lamination of a polymer film and a metal thin film is generally performed by bonding by heating and melting, and bonding using an adhesive for lamination.
Liquid type is used. However, in the case of a urethane-based two-part adhesive, when a non-polar substrate such as polypropylene or polyethylene is used as a polymer film, the adhesiveness to a metal thin film is not sufficient, or when a laminate is used as a container, If the contents are low molecular weight, high polar compounds, or corrosive compounds, these compounds that have passed through the polymer film dissolve in the adhesive layer and diffuse through the inside to reach the bonding interface, causing delamination and metal surfaces. There are problems such as corrosion.

[0004] In order to prevent these problems, there is a method of increasing the crosslinking density of the adhesive or introducing a hard skeleton such as an aromatic ring in order to suppress the diffusion rate inside the adhesive layer. Problems such as remarkable impairment of the flexibility of the layer and cracking and peeling during post-processing occur. In addition, since the urethane bond has a high polarity, there is a problem that a high-polarity low-molecular-weight compound as a content is easily dissolved in the adhesive layer, and the permeability of the adhesive layer cannot be suppressed.

[0005] There are also methods of co-extrusion of a modified polyolefin having a polar group, and fusion by heating a modified polyolefin film. However, these methods are slow in processing speed and insufficient in adhesion. Met.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly flexible adhesive layer having high adhesion to polyolefins and metals and having high resistance to organic solvents, particularly highly polar compounds. It is an object of the present invention to provide a laminated body having the same and a thin film battery using the same as an exterior material.

[0007]

Means for Solving the Problems As a result of extensive studies, the present inventors have found that a metal thin film and a polymer film are adhered to each other in a laminate in which a polymer film is laminated on at least one surface of a metal thin film. The present inventors have found that all the above-mentioned problems can be solved by using a polyolefin-based elastomer having a polar group which is soluble in an organic solvent as an adhesive layer, and reached the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The laminate of the present invention is generally formed by laminating a polymer film on at least one surface of a metal thin film. Preferably, a polymer film is laminated on both surfaces of a metal thin film. In this case, it is sufficient that at least one surface is soluble in an organic solvent and a polyolefin-based elastomer having a polar group is used as an adhesive, and both surfaces are soluble in an organic solvent and a polyolefin-based elastomer having a polar group is used as an adhesive. May be used.

When a container is formed using the laminate of the present invention, a polymer film laminated on a metal thin film via a polyolefin elastomer having a polar group, which is soluble in an organic solvent, is in contact with the contents. It is preferable to use a laminate.

The metal constituting the metal thin film used in the present invention usually includes aluminum, iron, tinplate and the like.
Preferably it is aluminum. The thickness of the metal thin film is usually 1 to 100 μm, preferably 5 to 50 μm.

As the polymer film used in the present invention, polyethylene, polypropylene, polyethylene vinyl acetate copolymer, polystyrene, polyamide,
Acrylic, polyvinyl alcohol and the like are used. The thickness of the polymer film is usually 1 to 500 µm, preferably 10 to 300 µm.

In the case of manufacturing a container such as a bag by heat-sealing the laminates of the present invention, the surface in contact with the laminates is preferably a polymer film which can be bonded by heat sealing. As the film, polyethylene, polypropylene, polyethylene vinyl acetate copolymer or the like is used.

The polyolefin elastomer which is soluble in an organic solvent and has a polar group and is used as an adhesive layer for bonding a metal thin film and a polymer film and which constitutes a polyolefin elastomer having a polar group is usually a styrene / butadiene block copolymer, a styrene / butadiene block copolymer, or a styrene / butadiene block copolymer. Examples include an isobutylene block copolymer, a styrene / butadiene / styrene block copolymer, a styrene / isoprene block copolymer, a styrene / isoprene / styrene block copolymer, and a hydrogenated product thereof. Among them, a styrene / butadiene block copolymer, a styrene / isobutylene block copolymer, a styrene / butadiene / styrene block copolymer, or a hydrogenated product thereof is preferably used.

Styrene-butadiene block copolymer,
The styrene / isobutylene block copolymer or styrene / butadiene / styrene block copolymer can be obtained by a known method, for example, a polymerization method described in US Pat. No. 3,265,765. Generally, it is obtained by solution polymerization of a mixture of styrene and a conjugated diene monomer such as butadiene or isoprene in the presence of a polymerization catalyst.

By hydrogenating the intramolecular double bond of these block polymers, an elastomer having improved thermal stability can be obtained. The hydrogenation is carried out by a conventionally known method, for example, described in Japanese Patent Publication Nos. 42-8704 and 43-6636.

The polar groups of the polyolefin elastomer include carboxyl groups, acid anhydride groups, hydroxyl groups,
Examples include a phosphoric acid group, a phosphorous acid group, a sulfuric acid group, a sulfurous acid group, an amino group, a cyano group, and a nitro group. Among them, a carboxyl group and an acid anhydride group are preferred.

The polyolefin elastomer having a polar group is obtained by using a polyolefin elastomer as a raw material.
It is obtained by graft polymerization of an α, β-unsaturated carboxylic acid or its anhydride in the presence of a radical initiator.

As the graft polymerization method, a polyolefin-based elastomer, an α, β-unsaturated carboxylic acid or its anhydride, and a radical initiator are melt-kneaded using an extruder and subjected to radical polymerization, or radical polymerization is initiated with the polyolefin-based elastomer. The method includes dissolving the agent in an aromatic hydrocarbon-based solvent such as toluene, xylene, chlorobenzene, or benzene, adding an α, β-unsaturated carboxylic acid or an anhydride thereof, and performing radical polymerization under heating.

As the α, β-unsaturated carboxylic acid or its anhydride, acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, crotonic acid, fumaric acid, maleic anhydride and the like are usually used. In the case of polybasic acids such as maleic acid and fumaric acid, their half alkyl esters may be used.

These α, β-unsaturated carboxylic acids or anhydrides thereof may be used in combination with other vinyl monomers such as acrylonitrile, acrylamide, vinyl chloride and 2-hydroxyacrylate.

The polyolefin elastomer having a polar group, which is a graft polymer obtained by such radical polymerization, contains an unreacted α, β-unsaturated carboxylic acid or an anhydride thereof. Is preferably removed by repeating reprecipitation and washing.
After the washing, the remaining solvent is usually removed by drying under reduced pressure or the like.

The radical polymerization initiator may be any of known ones, for example, alkyl peroxide, aryl peroxide, acyl peroxide, aroyl peroxide, ketone peroxide, peroxycarbonate,
Organic peroxides such as peroxycarboxylate, azonitrile and the like can be mentioned. Examples of the alkyl peroxide include diisopropyl peroxide, di-tert-butyl peroxide, and tert-butyl hydroperoxide; examples of aryl peroxide include dicumyl peroxide and cumyl hydroperoxide; and examples of acyl peroxide include dilauroyl. Examples of peroxides include aroyl peroxides such as dibenzoyl peroxide; examples of ketone peroxides include methyl ethyl ketone peroxide and cyclohexane peroxide; examples of azonitrile include azobisisobutyronitrile and azobisisopropionitrile.

The number average molecular weight of the polar group-containing polyolefin elastomer thus obtained is usually 5
000 to 500,000, preferably 10,000 to 200
000, more preferably 20,000 to 100,000.

The polyolefin elastomer having a polar group contains α, β-unsaturated carboxylic acid or its anhydride in an amount of usually 0.1 to 50% by weight, preferably 0.5 to 50% by weight.
The content is 30% by weight, more preferably 1 to 10% by weight.

In the present invention, the term "soluble in an organic solvent" refers to a substance which is soluble usually in an amount of 1 g or more, preferably 5 g or more, in 100 ml of toluene.

The polyolefin elastomer soluble in an organic solvent and having a polar group is a styrene / butadiene block copolymer, a styrene / isobutylene block copolymer, a styrene / butadiene / styrene block copolymer or a hydrogenated product thereof. It can also be used in combination with other resins such as chlorinated rubber, chlorinated polypropylene and its grafted maleic anhydride. The other resin is a polyolefin elastomer 10 having a polar group, which is soluble in an organic solvent.
The compounding amount is usually 10 to 1000 parts by weight, preferably 50 to 500 parts by weight, based on 0 parts by weight. Further, the weight of the polar group contained in the polyolefin elastomer having a polar group soluble in an organic solvent is usually 0.5 to the weight of the polyolefin elastomer having a polar group which is soluble in another resin and an organic solvent. It is preferable to adjust the grafting amount of the polar group and the addition amount of other resins so that the amount becomes not less than% by weight.

The polyolefin-based elastomer soluble in an organic solvent and having a polar group is used after being dissolved in an organic solvent.

Examples of the organic solvent which dissolves the polyolefin elastomer having a polar group which are soluble in an organic solvent include aromatic hydrocarbons such as toluene, xylene and chlorobenzene, and aliphatic hydrocarbons such as tetralin and mineral spirit. A mixed solvent of acetone, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone, and isophorone, esters such as ethyl acetate, butyl acetate, and cellosolve acetate, and methylene chloride, tetrahydrofuran, and dimethylformamide are used. .

The amount of the organic solvent to be added is determined by the ease with which the solution can be applied to the substrate. The content of the polar group-containing polyolefin-based elastomer in the organic solvent-soluble polar group-containing polyolefin-based elastomer solution is determined. Is usually 0.5 to 50% by weight, preferably 2 to 30% by weight.

A pigment may be added to the adhesive layer used in the present invention. As the pigment, an inorganic pigment or an organic pigment usually used for a paint is used.

Examples of the inorganic pigments include carbon black, graphite, titanium dioxide, calcium carbonate, barium sulfate, calcium silicate, iron oxide, chromium oxide, talc, and kaolin. Organic pigments include cochineal lake, naphthol and green B, Naphthol Yellow S, Toluidine
Red, phthalocyanine blue and the like. These pigments are used alone or in combination of two or more.

The adhesive layer may further contain additives such as a surface conditioner, an anti-settling agent, an antioxidant, a light stabilizer, an ultraviolet absorber, and a pigment dispersant, if necessary.

The laminate of the present invention is usually coated with an organic solvent solution in which a polyolefin elastomer having a polar group soluble in an organic solvent and dissolved in an organic solvent is applied to a polymer film or a metal thin film, dried, and then laminated with a metal thin film or a polymer film.
It is manufactured by crimping.

When the solution of the polyolefin-based elastomer having a polar group is applied, the thickness of the dried coating film is usually 0.1%.
It is performed by spraying, brushing, rolling, or the like so that the thickness is 100 μm, preferably 1 to 50 μm, and more preferably 2 to 30 μm.

Drying is carried out usually at 20 to 100 ° C., usually for several seconds to tens of minutes, and pressure bonding is usually carried out at 0.1 to 10 kg / cm ² .

The laminate of the present invention can be suitably used not only as food packaging materials such as retort foods and seasonings, but also as industrial simple packaging materials such as detergents, inks, paints and adhesives, and as containers constituting batteries. .

The case where the laminate of the present invention is used as a laminate for battery packaging will be described below.

In this case, the laminate of the present invention is used as a container for housing a battery element having a positive electrode and a negative electrode.

The battery element is not particularly limited as long as it can function as a battery, but in the present invention, it is preferably a non-aqueous battery, particularly a lithium battery using lithium as an electromotive substance, It is preferably a lithium secondary battery. Lithium as an electromotive substance is a metal component that becomes an ion and electrochemically participates in charging / discharging of a secondary battery and generates an electromotive force. Hereinafter, the present invention will be described using a lithium secondary battery as an example.

The positive electrode 1 or the negative electrode 2 is usually formed on a current collector 5 as shown in FIG. The positive electrode 1 or the negative electrode 2 is preferably formed on both surfaces of the current collector 5, but may be formed on one surface. As the current collector 5, a foil made of a metal such as aluminum, copper, nickel, and SUS can be generally used. A preferred material for the positive electrode current collector is aluminum. The positive electrode and the negative electrode, which are preferably made of copper as the negative electrode current collector, each have a corresponding active material, and usually further have a binder. As a positive electrode active material, occludes lithium ions
Both inorganic and organic compounds can be used as long as they can be released. Examples of the negative electrode active material capable of inserting and extracting lithium ions that can be used for the negative electrode include a carbon-based material such as graphite and coke. Since these positive electrode active material and negative electrode active material are usually bound on the current collector, it is preferable to use a binder. As the binder, inorganic compounds such as silicate and glass, and various resins mainly composed of polymers can be used.

As shown in FIG. 2, an electrolyte layer 3 is formed between the positive electrode 1 and the negative electrode 2. The material of the electrolyte layer 3 usually includes various electrolytes such as an electrolyte having fluidity and a non-fluid electrolyte such as a gel electrolyte and a completely solid electrolyte.
Electrolyte or gel electrolyte is preferable on the characteristics of the battery,
Further, a non-fluid electrolyte is preferable for safety. In particular, when a non-fluid electrolyte is used, liquid leakage can be more effectively prevented from a battery using a conventional electrolytic solution, so that the advantage of using the laminate of the present invention can be maximized.

The electrolytic solution used for the electrolyte layer is usually obtained by dissolving a supporting electrolyte in a non-aqueous solvent. As a supporting electrolyte, the electrolyte is stable to the positive electrode and the negative electrode,
In addition, any non-aqueous substance can be used as long as lithium ions can move to perform an electrochemical reaction with the positive electrode active material or the negative electrode active material. LiPF ₆ in particular, LiAsF _6, LiSbF _6, LiB
F ₄ , LiClO ₄ , LiI, LiBr, LiCl, Li
Lithium salts such as AlCl, LiHF ₂ , LiSCN, and LiSO ₃ CF ₂ are mentioned.

When these supporting electrolytes are used in the state of being dissolved in a non-aqueous solvent, the concentration is generally 0.5 to 2.5 m
ol / L. The nonaqueous solvent in which these supporting electrolytes are dissolved is not particularly limited, but a solvent having a relatively high dielectric constant is preferably used. Specifically, ethylene carbonate, cyclic carbonates such as propylene carbonate, dimethyl carbonate, diethyl carbonate, acyclic carbonates such as ethyl methyl carbonate, tetrahydrofuran, 2-methyltetrahydrofuran, glymes such as dimethoxyethane, γ-butyrolactone and the like Examples thereof include lactones, sulfur compounds such as sulfolane, and nitriles such as acetonitrile. One or two of these
Mixtures of more than one species can be used.

Among these, one or more solvents selected from cyclic carbonates such as ethylene carbonate and propylene carbonate, and acyclic carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are particularly suitable. is there. In addition, those in which a part of hydrogen atoms in these molecules are substituted with halogen or the like can also be used. Further, additives and the like may be added to these solvents.

The gel electrolyte that can be used for the electrolyte layer is usually obtained by holding the above-mentioned electrolyte solution with a polymer. That is,
The gel electrolyte is one in which the electrolyte is generally held in a polymer network and the fluidity as a whole is significantly reduced. Such a gel electrolyte exhibits properties such as ionic conductivity that are close to those of a normal electrolyte solution, but fluidity, volatility and the like are significantly suppressed, and safety is enhanced.
The ratio of the polymer in the gel electrolyte is preferably 1 to 50% by weight. If the temperature is too low, the electrolyte cannot be held, and a liquid leak may occur. If it is too high, the ionic conductivity tends to decrease and battery characteristics tend to deteriorate.

A completely solid electrolyte layer can be used as the electrolyte layer. As such a solid electrolyte, various solid electrolytes known so far can be used. For example, it can be formed by mixing the polymer used in the gel electrolyte and the supporting electrolyte salt at an appropriate ratio. In this case, in order to increase the conductivity, it is preferable to use a polymer having a high polarity and to have a skeleton having many side chains.

As the electrolyte layer, a material obtained by impregnating a spacer such as a porous film with the above electrolyte may be used.

A battery element is obtained by laminating a positive electrode and a negative electrode via an electrolyte layer. The battery element may have a flat plate shape by laminating a positive electrode, a negative electrode, and an electrolyte layer in a thickness direction, or may have a substantially cylindrical shape or a flat cylindrical shape by laminating it after lamination.

For example, as shown in FIG. 1, a positive electrode composition is laminated on both surfaces of a current collector 5 to obtain a plate-shaped positive electrode 1. The negative electrode material 2 is formed into a plate shape by the same method, and the positive electrode 1 and the negative electrode 2 formed into a plate shape are alternately laminated via the electrolyte layer 3 as shown in FIG.

If necessary, the positive electrode 1, the electrolyte layer 3
As shown in FIG. 4, the battery element on which the negative electrode 2 and the negative electrode 2 are stacked may be stacked in a direction in which the positive electrode 1 or the negative electrode 2 contacts. Such a configuration is particularly effective when a positive electrode or a negative electrode is formed on one surface of the current collector.

In both cases of FIGS. 2 and 3, the battery has a structure in which a plurality of flat battery elements are stacked in the thickness direction.

The planar shape of the electrode is arbitrary, and may be a quadrilateral, a circle, a polygon, or the like. Normally, the current collector 5 is provided with tabs 5a and 5b for lead connection.

When the electrode has a quadrangular shape, a tab 5a projecting from the current collector 5 of the positive electrode 1 is usually formed on one side of one side of the electrode as shown in FIG. Also, a tab 5b is formed on the opposite side of the same side.

The stacking of a plurality of battery elements is effective in increasing the capacity of the battery. At this time, the tabs 5a and 5b from each of the battery elements are usually connected in the thickness direction. As a result, a positive and negative lead connection terminal is formed. As a result, a large-capacity battery element 4 can be obtained.

As shown in FIG. 5, a lead 11 made of a flaky metal part of which is exposed to the outside of the container is usually connected to the lead connection terminal. As a result, lead and positive electrode,
The negative electrode is electrically coupled. The tabs 5a and 5b can be connected by welding using an ultrasonic welding machine, and the tabs 5a and 5b can be connected to the leads 11 by resistance welding such as spot welding, ultrasonic welding, or laser welding.

As the structure of the container, any structure may be used as long as it has mechanical strength and has a sealing property. For example, as shown in FIG. The battery element 4 may be interposed between the six and the periphery thereof may be sealed. Since the laminate of the present invention is resistant to a high-polarity, high-dielectric-constant solvent used as an electrolytic solution, the metal thin film and the polymer film are unlikely to peel off even when used for a long time as a battery container, There are advantages in that leakage of the electrolyte is unlikely to occur and that contact with outside air or the like can be effectively blocked.

In order to bond the laminates together, it is preferable that the innermost surface of the laminates be made of a layer made of a heat-fusible resin such as polyethylene or polypropylene. The container is preferably formed by heat-sealing the periphery of the film.

It is preferable that the battery element is vacuum-sealed in the case. As a result, a pressing force acts on the battery element, so that battery characteristics such as cycle characteristics can be improved.

[0059]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. In the following, “part” indicates “part by weight” and “%” indicates “% by weight”. <Production Example 1> 1 l of xylene and a hydrogenated styrene / isobutylene block copolymer (Clayton GX manufactured by Shell Chemical Co., Ltd.) were placed in a stainless steel pressure-resistant reaction vessel equipped with a thermometer and a stirrer.
1701) 100 g was charged and the system was purged with nitrogen.
After the temperature was raised to 5 ° C., while stirring, a xylene solution of maleic anhydride (1 g / 10 ml) and a xylene solution of dicumyl peroxide (0.15 g / 10 ml) were added through separate conduits.
It was added dropwise over time, and finally 6 g of maleic anhydride and 0.9 g of dicumyl peroxide were supplied into the system. After completion of the reaction, the reaction solution was cooled to around room temperature, acetone was added,
The precipitated maleic anhydride graft block copolymer is separated by filtration and washed repeatedly with acetone. The filtered product was dried under reduced pressure while heating, and the modified resin in the form of a white powder was redissolved in toluene / methyl isobutyl ketone (= 9/1 by weight) to obtain a resin solution 1 of 20% by weight. The content of maleic anhydride in this modified resin was 3.8% by weight as a result of neutralization titration. Further, the number average molecular weight was 40,000.

<Production Example 2> In a stainless steel pressure-resistant reaction vessel equipped with a thermometer and a stirrer, 1 l of xylene and hydrogenated styrene.
100 g of a mixture of a butadiene / styrene block copolymer and a hydrogenated styrene / butadiene block copolymer (Clayton G1726 manufactured by Shell Chemical Co., Ltd.) was charged, the system was purged with nitrogen, and the temperature was raised to 125 ° C., followed by stirring. A maleic anhydride xylene solution (1 g / 10 ml) and a dicumyl peroxide xylene solution (0.15 g / 10 m
1) was added dropwise from a separate conduit over 6 hours, and finally 6 g of maleic anhydride and 0.9 g of dicumyl peroxide were fed into the system. After the completion of the reaction, the reaction solution is cooled to around room temperature, acetone is added, and the precipitated maleic anhydride graft block copolymer is separated by filtration and washed repeatedly with acetone. The filtrate was dried under reduced pressure while heating, and the resulting modified resin in the form of a white powder was redissolved in toluene / methyl isobutyl ketone (= 9/1 by weight) to give a 20% by weight resin solution 2.
And The content of maleic anhydride in this modified resin was 3.7% by weight as a result of neutralization titration. The number average molecular weight was 45,000.

<Production Example 3> 1 l of xylene and hydrogenated styrene were placed in a stainless steel pressure-resistant reaction vessel equipped with a thermometer and a stirrer.
100 g of a butadiene / styrene block copolymer (Clayton G1652 manufactured by Shell Chemical Co., Ltd.) was charged, the atmosphere in the system was replaced with nitrogen, the temperature was raised to 125 ° C., and then a xylene solution of maleic anhydride (1 g / 10 ml) was added with stirring. Xylene solution of Mil peroxide (0.15g / 10ml)
Was dropped from a separate conduit over 6 hours, and finally 6 g of maleic anhydride and 0.9 g of dicumyl peroxide were fed into the system. After completion of the reaction, the reaction solution was cooled to around room temperature,
Acetone is added and the precipitated maleic anhydride graft block copolymer is filtered off and washed repeatedly with acetone. The filtered product was dried under reduced pressure while heating, and the resulting modified resin in the form of a white powder was treated with toluene / methyl isobutyl ketone (= 9).
/ 1 weight ratio) to obtain a resin solution 3 of 20% by weight. The content of maleic anhydride in this modified resin was 3.4% by weight as a result of neutralization titration. The number average molecular weight is 50
000.

<Examples 1 to 5> As shown in Table 1, using the modified resin solutions obtained in Production Examples 1 to 3, a dry film thickness of 10% was formed on an unstretched polypropylene film whose surface was degreased.
μm and dried at room temperature for 30 minutes.
The film was further dried at 30 ° C. for 30 minutes, and pressed with an aluminum foil having a thickness of 30 μm at a pressure of 10 kg / cm ² to obtain a laminate. <Comparative Examples 1 to 3> Laminates were obtained in the same manner as in the examples using the resin solutions shown in Table 1. <Test Method and Evaluation Method> (1) Adhesiveness The laminate was cut into a 2.5 cm wide strip and 100 mm / m2.
The peel strength was determined by maintaining the sample at 90 degrees with respect to the tensile direction at a tensile speed of in. (2) Solvent resistance The test piece was immersed in various solvents heated to 50 ° C., taken out after 24 hours, dried, measured again for peel strength, and evaluated by the retention to the measured initial peel strength. The results were represented by ○: retention rate of 80% or more, Δ: retention rate of 50 to 80%, and X: retention rate of 50% or less.

[0063]

[Table 1]

[0064]

According to the laminate of the present invention, the adhesive used for bonding the metal thin film and the polymer film is a polyolefin,
It has high adhesion to metals, and the resulting laminate has excellent resistance to highly polar solvents and corrosive contents, and is highly flexible, so it is used as an exterior material for shielding from the outside atmosphere It is extremely useful.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an example of an electrode.

FIG. 2 is a longitudinal sectional view of an example of a battery element in which electrodes are stacked.

FIG. 3 is a plan view of the battery element of FIG. 2;

FIG. 4 is a longitudinal sectional view showing another example of a battery element.

FIG. 5 is a longitudinal sectional view showing a relationship between tabs and leads of a plurality of battery elements.

FIG. 6 is a perspective view showing an example of a battery in which a battery element is housed in a case including two case members.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Electrolyte layer 4 Battery element 5a, 5b Tab 6 Laminated body 11 Lead

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4F100 AB01A AB10A AB33A AK01B AK07B AK09C AK09G AK09J AK12C AK12G AK12J AK73C AK73G AK73K AL02C AL02G AL04C AL04G AL07C AL07G AL09C AL09G BA02B JB BABJB02J AA17 CC02 CC06 CC10 DD14 KK02

Claims (7)

[Claims] 1. A laminate comprising a polymer film laminated on at least one surface of a metal thin film, wherein the metal thin film and the polymer film are interposed via an adhesive layer made of a polyolefin elastomer having a polar group, which is soluble in an organic solvent. A laminated body characterized in that the laminated body is laminated. 2. The laminate according to claim 1, wherein the metal thin film is made of aluminum. 3. The polyolefin elastomer is a styrene / butadiene block copolymer, a styrene / isobutylene block copolymer, a styrene / butadiene / styrene block copolymer or a hydrogenated product thereof. Or the laminate according to 2. 4. The laminate according to claim 1, wherein the polar group is a carboxyl group or an acid anhydride group. 5. The laminate according to claim 1, wherein the polar group is obtained by graft-polymerizing an α, β-unsaturated carboxylic acid or an anhydride thereof. body. 6. The laminate according to claim 5, wherein the α, β-unsaturated carboxylic acid or its anhydride is maleic anhydride. 7. The laminate according to claim 1, wherein the content of the polar group is 0.1 to 50% by weight based on the polyolefin elastomer having the polar group.