CN111279509A - Battery packaging material and battery - Google Patents

Abstract

The battery packaging material of the present invention is composed of a laminate having at least a base material layer, a barrier layer and a heat-sealable resin layer in this order, wherein the base material layer has at least a polyamide resin layer, an adhesive resin layer and a polyester resin layer in this order from the side of the barrier layer, the thickness of the polyester resin layer is 6 [ mu ] m or less, and the value obtained by dividing the impact strength (J) of the laminate measured from the side of the base material layer by the thickness (μm) of the laminate is 0.015J/μm or more according to ASTM D3420.

Description

Packaging materials and batteries for batteries

technical field

The present invention relates to a battery packaging material and a battery.

Background technique

At present, various types of batteries have been developed, but in all batteries, packaging materials are indispensable components in order to encapsulate battery elements such as electrodes and electrolytes. At present, metal packaging materials are widely used as packaging materials for batteries.

On the other hand, in recent years, with the performance enhancement of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., various shapes are required for batteries, and thinning and weight reduction are also required. However, it is difficult to cope with the diversification of shapes with the metal battery packaging materials commonly used at present, and there is a disadvantage that there is a limit to the weight reduction.

Therefore, in recent years, as a packaging material for batteries that can be easily processed into various shapes and can achieve thinning and weight reduction, a material in which a base material, a barrier layer, and a thermally fusible resin layer are laminated in this order has been proposed. A film-like laminate (for example, refer to Patent Document 1).

In such a battery packaging material, a concave portion is usually formed by molding, a battery element such as an electrode and an electrolyte solution is arranged in the space formed by the concave portion, and the heat-fusible resin layers are thermally welded to each other. The inside of the packaging material accommodates the battery of the battery element.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2008-287971

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

In vehicles and mobile devices, strong shocks are sometimes applied when products are transported or used, and strong shocks are also applied to batteries used in these products. When a strong impact is applied to the battery and the battery packaging material is damaged, the electrolyte solution and the like may leak to the outside, and therefore, the battery packaging material is required to have high impact resistance.

On the other hand, in recent years, high-capacity and thinning have been demanded for batteries, and along with this, further thinning of battery packaging materials has also been demanded. However, when the thickness of the battery packaging material is reduced, there is a problem that the impact resistance decreases.

In addition, in the battery manufacturing process, when the electrolyte solution is accommodated in a package formed of the battery packaging material, the electrolyte solution may adhere to the outer surface of the battery packaging material, the surface may be discolored, and the product may become defective.

In this way, there are the above-mentioned technical problems caused by the battery packaging material, the manufacturing process of the battery, and the usage of the battery, and a method capable of solving all of these technical problems has been demanded.

Under such circumstances, the main object of the present invention is to provide a battery packaging material having high impact resistance and electrolyte resistance. Another object of the present invention is to provide a battery using the battery packaging material.

Technical solutions for solving technical problems

In order to solve the above-mentioned technical problems, the present inventors have made intensive studies. As a result, it was found that a battery packaging material comprising a laminate having at least a base material layer, a barrier layer and a heat-fusible resin layer in this order has high impact resistance and electrolyte resistance, The base material layer has at least a polyamide resin layer, an adhesive resin layer and a polyester resin layer in this order from the barrier layer side, the thickness of the polyester resin layer is 6 μm or less, and the laminate is from the base material layer side according to the regulations of ASTM D3420. The value obtained by dividing the measured impact strength (J) by the thickness (μm) of the laminate is 0.015 J/μm or more. The present invention has been completed based on these findings.

That is, this invention provides invention of the following aspects.

Item 1. A battery packaging material comprising at least a laminate having a base material layer, a barrier layer, and a heat-fusible resin layer in this order,

The base material layer has at least a polyamide resin layer, an adhesive resin layer and a polyester resin layer in this order from the barrier layer side,

The thickness of the polyester resin layer is 6 μm or less,

The value obtained by dividing the impact strength (J) of the laminate measured from the base material layer side by the thickness (μm) of the laminate is 0.015 J/μm or more based on ASTM D3420.

Item 2. The battery packaging material according to Item 1, wherein an adhesive layer is provided between the base material layer and the barrier layer,

The hardness measured by the nanoindentation method of the said adhesive resin layer and the said adhesive bond layer is 50 MPa or less, respectively.

Item 3. The battery packaging material according to Item 1 or 2, wherein the adhesive resin layer is made of an acid-modified polyolefin-based resin, an acid-modified styrene-based elastomer resin, and an acid-modified polyester-based resin At least one of the elastomer resins is formed.

Item 4. The battery packaging material according to any one of Items 1 to 3, wherein the heat-fusible resin layer is made of unstretched polypropylene.

Item 5. The battery packaging material according to any one of Items 1 to 4, wherein the ratio of the thickness of the polyester resin layer to the thickness of the polyamide resin layer is 0.5 or less.

Item 6. The battery packaging material according to any one of Items 1 to 5, wherein the laminate has a thickness of 180 μm or less.

Item 7. The battery packaging material according to any one of Items 1 to 6, wherein the polyamide resin layer is made of nylon.

Item 8. The battery packaging material according to any one of Items 1 to 7, wherein the polyester resin layer is made of polyethylene terephthalate.

Item 9. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is accommodated in a package formed of the battery packaging material according to any one of Items 1 to 8.

Invention effect

According to the present invention, a battery packaging material having high impact resistance and electrolyte solution resistance can be provided. According to the present invention, it is also possible to provide a battery using the battery packaging material.

Description of drawings

FIG. 1 is a schematic view showing an example of the cross-sectional structure of the battery packaging material of the present invention.

2 is a schematic view showing an example of a cross-sectional structure of the battery packaging material of the present invention.

3 is a schematic diagram showing an example of a cross-sectional structure of the battery packaging material of the present invention.

Detailed ways

The battery packaging material of the present invention is composed of a laminate having at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. The base material layer has at least a polyamide resin layer, an adhesive resin layer, and a polyester resin layer in this order from the barrier layer side. In addition, the thickness of the polyester resin layer is 6 μm or less. Further, the value obtained by dividing the impact strength (J) of the laminate measured from the base material layer side by the thickness (μm) of the laminate is 0.015 J/μm or more in accordance with ASTM D3420. By having such a configuration, the battery packaging material of the present invention can have high impact resistance and electrolyte solution resistance. Hereinafter, the battery packaging material of the present invention will be described in detail.

However, in this specification, the numerical range shown by "-" means "above" and "below". For example, a mark of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated structure and physical properties of battery packaging materials

As shown in FIG. 1 , the battery packaging material 10 of the present invention includes at least a laminate having a base material layer 1 , a barrier layer 3 and a heat-fusible resin layer 4 in this order. Moreover, the base material layer 1 has a polyamide resin layer 1a, an adhesive resin layer 1b, and a polyester resin layer 1c in this order from the barrier layer 3 side at least.

In the battery packaging material of the present invention, the polyester resin layer 1c of the base material layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-fusible resin layers 4 located on the periphery of the battery element are thermally welded to each other to seal the battery element, whereby the battery element is sealed.

In the battery packaging material 10 of the present invention, as shown in FIGS. 2 and 3 , between the base material layer 1 and the barrier layer 3 , for the purpose of improving their adhesiveness, if necessary, an adhesive bond may be provided. Agent layer 2. In addition, as shown in FIG. 3 , between the barrier layer 3 and the thermally fusible resin layer 4, for the purpose of improving their adhesiveness, an adhesive layer 5 may be provided as necessary.

The battery packaging material of the present invention is characterized in that the impact strength (J) measured from the side of the base material layer 1 of the laminate constituting the battery packaging material is divided by the laminate based on the regulations of ASTM D3420. The value P obtained by the thickness (μm) of the body is 0.015 J/μm or more. The base material layer 1 of the battery packaging material of the present invention has at least a polyamide resin layer 1a, an adhesive resin layer 1b and a polyester resin layer 1c in this order from the side of the barrier layer 3, and has such characteristics, although the polyester resin is Even when the thickness of the layer is set to 6 μm or less, high impact resistance and high electrolyte solution resistance can be exhibited. Among them, as the impact head of the measuring device, a tip hemispherical member having a radius of 12.7 mm and a smooth surface was used. For the measurement of impact strength, a laminate cut out to a diameter of 100 mm was used as a sample. The sample was fixed between two plates having a circular opening with a diameter of 89±0.5 mm in the center.

From the viewpoint of further improving the impact resistance, the impact strength (J) measured from the side of the base material layer 1 of the laminate constituting the battery packaging material is divided by the thickness (μm) of the laminate. As the lower limit of the value P, preferably about 0.015 J/μm or more, more preferably about 0.016 J/μm or more, and as the upper limit, preferably about 0.020 J/μm or less, more preferably about 0.019 J/μm or less. Moreover, as a preferable range of this value P, about 0.015-0.020J/micrometer, about 0.015-0.019J/micrometer, about 0.016-0.020J/micrometer, and about 0.016-0.019J/micrometer are mentioned.

As a method of setting this value P to the above-mentioned value, a method can be adopted in which, as the base material layer 1, at least a polyamide resin layer 1a, an adhesive resin layer 1b, and a polyester resin are used in this order from the barrier layer 3 side. After the base material layer of the layer 1c and the polyester resin layer 1c have a thickness of 6 μm or less, the material and thickness of each layer to be described later are adjusted.

In addition, in the battery packaging material of the present invention, the impact strength (J) is considered to be the relationship with the thickness of the laminate constituting the battery packaging material, and the above-mentioned value P may be satisfied, preferably 1.4J or more. , more preferably 1.6J or more, still more preferably 1.7J or more. Moreover, as an upper limit of the impact strength (J), 3.0J and 2.8J are mentioned, for example.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited, but from the viewpoint of suppressing an increase in the thickness of the battery packaging material and imparting high impact resistance, for example, about 180 μm or less, preferably About 160 μm or less, more preferably about 60 to 180 μm, still more preferably about 60 to 160 μm, still more preferably about 80 to 160 μm, particularly preferably about 100 to 160 μm.

2. Forming the layers of the battery packaging material

[Substrate layer 1]

In the battery packaging material 10 of the present invention, the base material layer 1 is a layer located on the outermost layer side. The base material layer 1 has at least a polyamide resin layer 1a, an adhesive resin layer 1b, and a polyester resin layer 1c in this order from the barrier layer 3 side.

The polyamide resin layer 1a is a layer made of polyamide, and by being made of polyamide, it has the function of imparting toughness and improving the moldability of the battery packaging material 10, and can also impart flexibility, puncture resistance, and cold resistance. In the present invention, the polyamide resin layer 1a is located on the side of the barrier layer 3 of the base material layer 1, and ensures the high impact resistance of the present invention together with the polyester resin layer 1c.

Specific examples of polyamides include: aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; Nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) and other hexamethylene diamine-isophthalic acid-terephthalic acid copolymers as structural units of formic acid amides, aromatic polyamides including polym-xylylene adipamide (MXD6), etc.; alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and lactam components, 4, Polyamides obtained by copolymerizing isocyanate components such as 4'-diphenylmethane-diisocyanate, polyesteramide copolymers as copolymers of copolyamides, polyesters, and polyalkylene ether glycols, and polyetheresteramide copolymers substances; their copolymers, etc. These polyamides may be used alone or in combination of two or more. Since the stretched polyamide film is excellent in stretchability, it can prevent whitening due to cracking of the resin of the base material layer 1 during molding, and is suitable for use as a raw material for forming the polyamide resin layer 1a.

Among polyamides, the polyamide resin layer 1a is preferably made of nylon.

The thickness of the polyamide resin layer 1a is preferably about 12 to 25 μm, more preferably about 15 to 24 μm, from the viewpoint of suppressing the increase in thickness of the battery packaging material and imparting high impact resistance.

In addition, the polyester resin layer 1c is a layer made of polyester. The polyester resin layer 1 c constitutes the outermost layer of the base material layer 1 . That is, the polyester resin layer 1c constitutes the outermost layer of the battery packaging material of the present invention, and exhibits excellent electrolyte resistance. In addition, as described above, the polyester resin layer 1c ensures the high impact resistance of the present invention together with the polyamide resin layer 1a.

Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyisophthalate Ethylene formate, copolyester mainly containing ethylene terephthalate as repeating unit, copolyester mainly containing butylene terephthalate as repeating unit, etc. In addition, specific examples of copolyesters having ethylene terephthalate as the main repeating unit include: ethylene terephthalate as the main repeating unit and ethylene isophthalate Polyester copolymers obtained by polymerizing alcohol esters (hereinafter, referred to as polyethylene glycol (terephthalate/isophthalate) and omitted), polyethylene glycol (terephthalate/isophthalate) isophthalate), polyethylene glycol (terephthalate/adipate), polyethylene glycol (terephthalate/sodium isophthalate sulfonate), poly Ethylene glycol (terephthalate/sodium isophthalate), polyethylene glycol (terephthalate/phenyl-dicarboxylate), polyethylene glycol (terephthalate) acid ester/decane dicarboxylate) etc. In addition, specific examples of copolyesters having butylene terephthalate as the main repeating unit include butylene terephthalate as the main repeating unit, which is combined with butylene isophthalate. Polyester (hereinafter referred to as polytetramethylene glycol (terephthalate/isophthalate) is omitted), polybutylene glycol (terephthalate/hexane) diacid), polytetramethylene glycol (terephthalate/sebacate), polytetramethylene glycol (terephthalate/decane dicarboxylate), polybutylene naphthalate esters, etc. These polyesters may be used alone or in combination of two or more. Polyester is excellent in electrolytic solution resistance, and has advantages such as being less likely to cause whitening to adhere to an electrolytic solution.

Among polyesters, the polyester resin layer 1c is preferably composed of polyethylene terephthalate, and more preferably composed of stretched polyethylene terephthalate.

The thickness of the polyester resin layer 1c may be 6 μm or less, and the thickness of the polyester resin layer 1c may be exemplified from the viewpoint of suppressing an increase in the thickness of the battery packaging material and imparting high impact resistance and electrolyte resistance. It is preferably about 1 to 6 μm, and more preferably about 1 to 5 μm.

From the viewpoint of suppressing an increase in the thickness of the battery packaging material and imparting high impact resistance and electrolyte resistance, regarding the ratio of the thickness of the polyester resin layer 1c to the thickness of the polyamide resin layer 1a (polyester resin layer Thickness of 1c/thickness of polyamide resin layer 1a), as the upper limit, preferably about 0.5 or less, more preferably about 0.3 or less, still more preferably about 0.25 or less; as the lower limit, preferably about 0.01 or more, more preferably about 0.03 or more , more preferably 0.04 or more. The range of the ratio is preferably about 0.01 to 0.5, about 0.01 to 0.3, about 0.01 to 0.25, about 0.03 to 0.5, about 0.03 to 0.3, about 0.03 to 0.25, about 0.04 to 0.5, about 0.04 to 0.3, and 0.04 to 0.25 or so.

The adhesive resin layer 1b is a layer made of resin for bonding the polyamide resin layer 1a and the polyester resin layer 1c. The adhesion mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent evaporation type, a thermal fusion type, a hot press type, an electron beam curing type, an ultraviolet curing type, and the like.

In this invention, it is preferable that the hardness measured by the nanoindentation method of the adhesive resin layer 1b is 50 MPa or less. In the battery packaging material of the present invention, the above-mentioned hardness of the adhesive resin layer 1b is 50 MPa or less, and the adhesive layer 2 to be described later located between the base material layer 1 and the barrier layer 3 is subjected to a nanoindentation method. When the measured hardness is also 50 MPa or less, excellent formability can be exhibited. Regarding this mechanism, for example, the following can be considered. That is, since the hardness of these layers is designed to be lower than that of ordinary adhesives, although the base material layer 1 has the polyester resin layer 1c (polyester resins are generally harder than polyamide resins such as nylon and have poor moldability), the adhesive The resin layer 1b and the adhesive layer 2 are also suitable for suppressing rapid deformation of the barrier layer 3 due to deformation of the base material layer 1 during molding, and as a result, the generation of cracks or pinholes in the barrier layer 3 can be effectively suppressed.

From the viewpoint of further improving the moldability of the battery packaging material, the hardness of the polyester resin layer 1c is preferably about 10 to 50 MPa, and more preferably about 15 to 40 MPa.

In this invention, the hardness measured by the nanoindentation method of the adhesive resin layer 1b and the adhesive bond layer 2 is the value measured by the following operation|movement, respectively. As the apparatus, a nanoindenter (“TriboIndenter TI950” manufactured by HYSITRON Corporation) was used. As the indenter of the nanoindenter, a Berkovich indenter (triangular pyramid) was used. Regarding the adhesive layer 2 Hardness, in an environment of 50% relative humidity and 23°C, the indenter is in contact with the surface of the adhesive layer 2 of the battery packaging material (the surface where the adhesive layer 2 is exposed, and the lamination direction of each layer is vertical direction), for 10 seconds, press the indenter into the adhesive layer from the surface to a load of 40μN, keep in this state for 5 seconds, and then release the load for 10 seconds. Use the maximum load _Pmax (μN) and The contact projection area A (μm ² ) at the maximum depth was calculated using P _max /A to calculate the indentation hardness (MPa). In addition, the hardness of the adhesive resin layer 1b may be combined with an adhesive except that the load is 10 μN. Layer 2 was similarly measured.

As an adhesive agent for forming the adhesive resin layer 1b, a resin composition containing a modified thermoplastic resin obtained by graft modification with an unsaturated carboxylic acid or an unsaturated carboxylic acid derivative component is preferably used. The modified thermoplastic resin preferably includes a polyolefin-based resin, a styrene-based elastomer, a polyester-based elastomer, or the like modified with an unsaturated carboxylic acid derivative component. This resin may be used alone or in combination of two or more. Moreover, as an unsaturated carboxylic acid derivative component, the acid anhydride of an unsaturated carboxylic acid, the ester of an unsaturated carboxylic acid, etc. are mentioned. As the unsaturated carboxylic acid derivative component, one type may be used alone, or two or more types may be used in combination.

Examples of the polyolefin-based resin in the modified thermoplastic resin include: low-density polyethylene, medium-density polyethylene, and high-density polyethylene; ethylene-α-olefin copolymer; homopolypropylene, block polypropylene, or random polypropylene ; Propylene-alpha olefin copolymers; copolymers formed by copolymerizing polar molecules such as acrylic acid and methacrylic acid with the above-mentioned materials; polymers such as cross-linked polyolefins, etc. The polyolefin resin may be used alone or in combination of two or more.

Examples of the styrene-based elastomer in the modified thermoplastic resin include copolymers of styrene (hard segment), butadiene, isoprene, or their hydrogenated products (soft segment). The polyolefin resin may be used alone or in combination of two or more.

As the polyester-based elastomer in the modified thermoplastic resin, a copolymer of a crystalline polyester (hard segment) and a polyalkylene ether glycol (soft segment) and the like can be mentioned. The polyolefin resin may be used alone or in combination of two or more.

Examples of the unsaturated carboxylic acid in the modified thermoplastic resin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, bicyclo[2,2, 1] Hept-2-ene-5,6-dicarboxylic acid, etc. In addition, examples of acid anhydrides of unsaturated carboxylic acids include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2,2,1]hept-2-ene-5,6. - Diformic anhydride, etc. In addition, examples of esters of unsaturated carboxylic acids include methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, rich Diethyl maleate, dimethyl itaconic acid, diethyl citraconic acid, dimethyl tetrahydrophthalic anhydride, bicyclo[2,2,1]hept-2-ene-5,6-di Esters of unsaturated carboxylic acids such as dimethyl formate, etc.

The modified thermoplastic resin can be obtained by heating and reacting 0.2 to 100 parts by mass of the unsaturated carboxylic acid derivative component with respect to 100 parts by mass of the thermoplastic resin as a matrix in the presence of a radical initiator.

The reaction temperature is preferably 50 to 250°C, more preferably 60 to 200°C. The reaction time also depends on the production method. In the case of the melt grafting reaction using a twin-screw extruder, the residence time in the extruder is preferably 2 to 30 minutes, and more preferably 5 to 10 minutes. In addition, the modification reaction may be carried out under any conditions of normal pressure and increased pressure.

As a radical initiator used in the said modification|denaturation reaction, an organic peroxide is mentioned. As the organic peroxide, various materials can be selected according to temperature conditions and reaction time, for example, alkyl peroxides, aryl peroxides, acyl peroxides, ketone peroxides, ketal peroxides, peroxides Carbonate, peroxyester, hydrogen peroxide, etc. In the case of the melt-grafting reaction by the above-mentioned twin-screw extruder, alkyl peroxides, peroxyketals, and peroxyesters are preferable, and di-tert-butyl peroxide, 2,5-dihydrogen peroxide, Methyl-2,5-di-tert-butylperoxy-hexyne-3, dicumyl peroxide.

The above-mentioned hardness of the adhesive resin layer 1b can be adjusted not only by adjusting the type of resin contained in the adhesive, but also by adjusting the molecular weight of the resin, the number of cross-linking points, the modification rate, the elongation ratio, the tensile strength, and the The elongation temperature and the like are adjusted to the above-mentioned values.

In addition, from the viewpoint of further improving the moldability of the battery packaging material, the hardness measured by the nanoindentation method of the polyester resin layer 1c is preferably about 300 to 400 MPa, more preferably about 300 to 350 MPa. Furthermore, as the hardness measured by the nanoindentation method of the polyamide resin layer 1a, it is preferably about 200 to 400 MPa, and more preferably about 200 to 350 MPa.

However, in the present invention, regarding the hardness measured by the nanoindentation method for the polyester resin layer 1c and the polyamide resin layer 1a, in the aforementioned method for measuring the hardness of the adhesive resin layer 1b, respectively, the measurement object of the hardness is The measurement can be performed in the same manner as the adhesive resin layer 1b except that the polyester resin layer 1c or the polyamide resin layer 1a is used and the press-fitting load is 100 μN.

The thickness of the adhesive resin layer 1b is preferably about 0.5 to 2 μm, more preferably about 0.8 to 1.2 μm, from the viewpoint of suppressing an increase in the thickness of the battery packaging material and imparting high impact resistance.

The base material layer 1 may have other layers in addition to the aforementioned polyamide resin layer 1a, adhesive resin layer 1b, and polyester resin layer 1c. Examples of materials constituting the other layers include epoxy resins, acrylic resins, fluororesins, polyurethanes, silicone resins, phenolic resins, polyetherimide, polyimide, mixtures or copolymers thereof, and the like. In addition, the polyamide resin layer 1a, the adhesive resin layer 1b, and the polyester resin layer 1c may each be a single layer or a multilayer.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, it is preferable that a lubricant is attached to the surface on the side of the base material layer 1 . The lubricant is not particularly limited, but an amide-based lubricant is preferably used. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, and the like. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, and the like. Specific examples of unsaturated fatty acid amides include oleic acid amide, erucic acid amide, and the like. Specific examples of the substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl amide Erucamide, etc. Moreover, as a specific example of methylolamide, methylol stearic acid amide etc. are mentioned. Specific examples of saturated fatty bisamides include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acidamide, and ethylenebishydroxyl amide. Stearic acid amide, ethylene bisbehenic acid amide, hexamethylene bis behenic acid amide, hexamethylene bis behenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-di Stearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc. Specific examples of the unsaturated fatty bisamides include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearic acid amide ethyl stearate and the like. In addition, specific examples of the aromatic bisamides include isoxylylene bisstearic acid amide, isoxylylene bishydroxystearic acid amide, and N,N'-distearyl isobenzene. Diformic acid amide, etc. The lubricant may be used alone or in combination of two or more.

When the lubricant exists on the surface of the base layer 1 side, the amount of the lubricant is not particularly limited, but in an environment with a temperature of 24° C. and a relative humidity of 60%, it is preferably about 3 mg/m ² or more, and more preferably 4 to 15 mg. /m ² or so, more preferably about 5 to 14 mg/m ² .

The thickness of the base material layer 1 is preferably about 15 μm or more, more preferably about 15 to 30 μm, even more preferably about 15 μm or more, from the viewpoint of suppressing the increase in the thickness of the battery packaging material and imparting high impact resistance and electrolyte resistance. About 20 to 30 μm.

[Adhesive layer 2]

In the battery packaging material 10 of the present invention, the adhesive layer 2 is a layer provided between the base material layer 1 and the barrier layer 3 as necessary in order to firmly adhere to them.

The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 and the barrier layer 3 to each other. The adhesive for forming the adhesive layer 2 may be a two-liquid curing type adhesive or a one-liquid curing type adhesive. In addition, the adhesion mechanism of the adhesive for forming the adhesive layer 2 is not particularly limited, either, and may be any of a chemical reaction type, a solvent evaporation type, a hot melt type, a hot press type, and the like.

In this invention, it is preferable that the hardness measured by the nanoindentation method of the adhesive bond layer 2 is 50 MPa or less. As described above, in the battery packaging material of the present invention, when the hardness of the adhesive resin layer 1b and the adhesive layer 2 measured by the nanoindentation method are both 50 MPa or less, excellent moldability can be exhibited. The measurement method of this hardness of the adhesive bond layer 2 is as mentioned above.

From the viewpoint of further improving the moldability of the battery packaging material, the hardness of the adhesive layer 2 is preferably about 10 to 50 MPa, and more preferably about 20 to 40 MPa.

Among them, the hardness of the adhesive layer 2 can be adjusted not only by adjusting the type of resin contained in the adhesive, but also by adjusting the molecular weight of the resin, the number of crosslinking points, the ratio of the main agent to the curing agent, the main agent The dilution ratio with the curing agent, the drying temperature, the aging temperature, and the aging time, etc., are adjusted to the above-mentioned values.

Specific examples of adhesive components that can be used to form the adhesive layer 2 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyethylene naphthalate. Polyester resins such as butylene diformate, polyethylene isophthalate, and copolyester; polyether adhesives; polyurethane adhesives; epoxy resins; phenolic resins; nylon 6. Polyamide resins such as nylon 66, nylon 12, and copolyamide; polyolefin resins such as polyolefins, carboxylic acid-modified polyolefins, and metal-modified polyolefins; polyvinyl acetate resins; cellulose-based adhesives (meth)acrylic resin; polyimide resin; polycarbonate; amino resin such as urea resin and melamine resin; chloroprene rubber, nitrile rubber, styrene-butadiene rubber and other rubbers; Silicone resin, etc. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, polyurethane-based adhesives are preferably used.

The thickness of the adhesive bond layer 2 is not particularly limited as long as it can function as an adhesive layer. For example, it is about 1 to 10 μm, preferably about 2 to 5 μm.

[Barrier layer 3]

In the battery packaging material of the present invention, the barrier layer 3 is a layer having a function of increasing the strength of the battery packaging material and preventing the intrusion of water vapor, oxygen, light, and the like into the battery. The barrier layer 3 can be formed of a metal foil, a metal vapor-deposited film, an inorganic oxide vapor-deposited film, a carbon-containing inorganic oxide vapor-deposited film, a film provided with these vapor-deposited layers, or the like, and is preferably a layer formed of a metal foil. Specific examples of the metal constituting the barrier layer include aluminum, stainless steel, titanium, and the like, and aluminum is preferably used. From the viewpoint of preventing the formation of wrinkles and pinholes in the barrier layer 3 when manufacturing the battery packaging material, the barrier layer is more preferably made of, for example, annealed aluminum (JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, It is formed of soft aluminum foil such as JIS H4000: 2014A8021P-O, JIS H4000: 2014 A8079P-O).

The thickness of the barrier layer 3 is not particularly limited as long as it can function as a barrier layer for water vapor or the like.

In addition, in order to stabilize adhesion, prevent dissolution, corrosion, and the like, it is preferable to perform chemical conversion treatment on at least one surface, preferably both surfaces, of the barrier layer 3 . Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of the barrier layer. Examples of the chemical conversion treatment include chromic acid using chromium compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium dihydrogen phosphate, chromate acetoacetate, chromium chloride, and potassium chromium sulfate. Salt treatment; phosphoric acid treatment using phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid, etc.; chemical conversion treatment using aminoated phenol polymers having repeating units represented by the following general formulas (1) to (4), etc. . Among them, in the aminated phenol polymer, the repeating units represented by the following general formulae (1) to (4) may be contained alone or in any combination of two or more.

In the general formulae (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. In addition, R ¹ and R ² are the same or different from each other, and represent a hydroxy group, an alkyl group or a hydroxyalkyl group. In the general formulae (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl. , tert-butyl and other straight-chain or branched-chain alkyl groups having from 1 to 4 carbon atoms. In addition, examples of the hydroxyalkyl group represented by X, R ¹ and R ² include hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, Linear or branched alkyl group having 1 to 4 carbon atoms substituted with one hydroxyl group, such as hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, and 4-hydroxybutyl . In the general formulae (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different from each other. In the general formulae (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having repeating units represented by general formulae (1) to (4) is preferably about 500 to 1 million, for example, and more preferably about 1000 to 20,000.

In addition, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, there may be mentioned a method in which fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate are dispersed in phosphoric acid by coating. The obtained substance is sintered at 150° C. or higher, whereby an acid-resistant coating is formed on the surface of the barrier layer 3 . In addition, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid-resistant coating film. Among them, examples of cationic polymers include polyethyleneimine, ionic polymer complexes composed of polyethyleneimine and a polymer having a carboxylic acid, and polymers obtained by graft-polymerizing primary amines on the acrylic main skeleton. Primary amine grafted acrylic resin, polyallylamine or its derivatives, aminophenol, etc. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Moreover, as a crosslinking agent, the compound which has at least 1 type of functional group chosen from an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, etc. are mentioned, for example. As these crosslinking agents, only one type may be used, or two or more types may be used in combination.

In addition, as a specific method of providing the acid-resistant coating, for example, as an example, at least the surface of the inner layer side of the aluminum foil is firstly subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid activation method, or the like. Degreasing treatment is performed by a known treatment method, and then the degreasing treated surface is coated with chromium phosphate, titanium phosphate, zirconium phosphate, zinc phosphate, etc. by known coating methods such as roll coating, gravure printing, and dipping. Treatment liquid (aqueous solution) containing metal phosphates and mixtures of these metal salts as main components; or treatment liquids (aqueous solutions) containing mixtures of non-metal phosphates and these non-metal salts as main components; or containing these and acrylics An acid-resistant coating can be formed by a treatment liquid (aqueous solution) of a mixture of a resin, a phenolic resin, or a urethane-based resin or a mixture of water-based synthetic resins. For example, when treated with a chromium phosphate-based treatment liquid, an acid-resistant coating containing chromium phosphate, aluminum phosphate, alumina, aluminum hydroxide, aluminum fluoride, etc. is formed; when treated with a zinc phosphate-based treatment liquid, An acid-resistant coating containing zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, and the like is formed.

In addition, as another example of a specific method for providing an acid-resistant coating, for example, at least the surface of the inner layer side of the aluminum foil is firstly subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid activation method, etc. An acid-resistant coating can be formed by performing degreasing treatment by a known treatment method, and then subjecting the degreasing treated surface to a known anodizing treatment.

In addition, as another example of the acid-resistant coating, a phosphate-based coating and a chromic acid-based coating can be mentioned. Examples of the phosphate system include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate; and examples of the chromic acid system include chromium chromate and the like.

In addition, as another example of the acid-resistant coating, by forming an acid-resistant coating such as phosphate, chromate, fluoride, triazine thiol compound, etc., it is possible to exhibit the effect of preventing aluminum from interacting with radicals during embossing. Delamination between material layers; prevent the dissolution and corrosion of the aluminum surface caused by the hydrogen fluoride generated by the reaction of the electrolyte and moisture, especially the dissolution and corrosion of the aluminum oxide on the surface of the aluminum, and improve the adhesion of the aluminum surface. (wettability); prevent delamination of substrate layer and aluminum during heat sealing; prevent delamination of substrate layer and aluminum during press molding in embossing type. Among substances for forming an acid-resistant film, an aqueous solution composed of three components, a phenolic resin, a chromium (III) fluoride compound, and phosphoric acid, is applied to the surface of aluminum, and the process of drying and sintering is favorable.

In addition, the acid-resistant coating includes a layer comprising cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent for crosslinking the anionic polymer, and the phosphoric acid or phosphate is 100 parts by mass relative to the cerium oxide. About 1-100 mass parts can be mix|blended. The acid-resistant coating film preferably has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent that crosslinks the cationic polymer.

Furthermore, it is preferable that the said anionic polymer is poly(meth)acrylic acid or its salt, or the copolymer which has (meth)acrylic acid or its salt as a main component. Moreover, it is preferable that the said crosslinking agent is at least 1 sort(s) chosen from the compound which has an arbitrary functional group among an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.

Moreover, it is preferable that the said phosphoric acid or phosphate is a condensed phosphoric acid or a condensed phosphate.

As for the chemical conversion treatment, only one chemical conversion treatment may be performed, or two or more chemical conversion treatments may be performed in combination. In addition, these chemical conversion treatments may be performed using one type of compound alone, or two or more types of compounds may be used in combination. Among the chemical conversion treatments, chromate treatment, chemical conversion treatment in which a chromium compound, a phosphoric acid compound and an aminated phenol polymer are combined, and the like are preferable. Among the chromium compounds, chromic acid compounds are preferred.

Specific examples of the acid-resistant coating include acid-resistant coatings containing at least one of phosphate, chromate, fluoride, and triazine mercaptan. In addition, an acid-resistant coating containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

In addition, specific examples of the acid-resistant coating include a phosphate-based coating, a chromate-based coating, a fluoride-based coating, a triazine thiol compound coating, and the like. As the acid-resistant coating, one of these may be used, or a combination of two may be used. Furthermore, as the acid-resistant coating, after degreasing the chemical conversion-treated surface of the aluminum foil, a treatment liquid containing a mixture of a metal phosphate and an aqueous synthetic resin, or a treatment liquid containing a mixture of a non-metal phosphate and an aqueous synthetic resin can be used. Treatment fluid is formed.

Among them, the composition analysis of the acid-resistant coating can be performed by, for example, time-of-flight secondary ion mass spectrometry. By analyzing the composition of the acid-resistant coating by time-of-flight secondary ion mass spectrometry, for example, a peak derived from at least one of Ce ⁺ and Cr ⁺ can be detected.

It is preferable to have an acid-resistant coating film containing at least one element selected from the group consisting of phosphorus, chromium, and cerium on the surface of the aluminum foil. Among them, it can be confirmed by X-ray photoelectron spectroscopy that the acid-resistant coating on the surface of the aluminum foil of the battery packaging material contains at least one element selected from the group consisting of phosphorus, chromium, and cerium. Specifically, first, in the battery packaging material, the heat-fusible resin layer, the adhesive layer, and the like laminated on the aluminum foil are physically peeled off. Next, the aluminum foil was placed in an electric furnace, and the organic components present on the surface of the aluminum foil were removed at about 300° C. for about 30 minutes. Then, the inclusion of these elements was confirmed by X-ray photoelectron spectroscopy on the surface of the aluminum foil.

The amount of the acid-resistant coating formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited. For example, when the above-mentioned chromate treatment is performed, the content ratio of the chromium compound per 1 m ² of the surface of the barrier layer 3 is desired. The content of the phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of chromium, the content of the phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and the content of the aminated phenol polymer is 1.0 to 200 mg. about, preferably about 5.0 to 150 mg.

The thickness of the acid-resistant coating film is not particularly limited, but from the viewpoints of the cohesive force of the coating film and the adhesive force with the aluminum foil and the heat-fusible resin layer, preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm, and further It is preferably about 1 to 50 nm. Here, the thickness of the acid-resistant coating can be measured by observation with a transmission electron microscope, or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

Regarding the chemical conversion treatment, after applying a solution containing a compound for forming an acid-resistant film on the surface of the barrier layer by bar coating, roll coating, gravure coating, dipping, etc., the barrier layer is heated by heating. The temperature reaches about 70 to 200 °C. In addition, before subjecting the barrier layer to chemical conversion treatment, the barrier layer may be previously subjected to degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this way, the chemical conversion treatment of the surface of the barrier layer can be performed more efficiently.

[Thermal fusion resin layer 4]

In the battery packaging material of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer for sealing the battery element by heat-sealing the heat-fusible resin layers to each other by heat fusion when the battery is assembled.

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-sealed, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin constituting the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, but preferably contains a polyolefin skeleton. The resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton and can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of the wavenumber of 1760 cm ^-1 and the vicinity of the wavenumber of 1780 cm ^-1 . However, when the acid modification degree is low, the peak becomes small and cannot be detected in some cases. In this case, analysis can be performed by nuclear magnetic resonance spectroscopy.

Specific examples of the above-mentioned polyolefins include polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene and block copolymers of polypropylene (for example, propylene and ethylene block copolymers), polypropylene random copolymers (such as propylene and ethylene random copolymers) and other polypropylenes; ethylene-butene-propylene terpolymers, etc. Among these polyolefins, polyethylene and polypropylene are preferably cited.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin constituting the monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, Isoprene, etc. In addition, as the cyclic monomer constituting the above-mentioned cyclic polyolefin, for example, cyclic olefins such as norbornene may be mentioned; specifically, cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornane may be mentioned. Cyclic dienes such as dienes, etc. Among these polyolefins, cyclic olefins are preferred, and norbornene is more preferred.

The above-mentioned acid-modified polyolefin is a polymer obtained by modifying the above-mentioned polyolefin by block polymerization or graft polymerization with an acid component such as a carboxylic acid. Examples of acid components used for modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or their acid anhydrides.

The above acid-modified cyclic polyolefin is obtained by substituting a part of the monomers constituting the cyclic polyolefin with α,β-unsaturated carboxylic acid or its anhydride and copolymerizing, or by making α,β-unsaturated carboxylic acid or It is a polymer obtained by block polymerization or graft polymerization of its acid anhydride and cyclic polyolefin. Regarding the carboxylic acid-modified cyclic polyolefin, it is the same as above. In addition, the carboxylic acid used for the modification is the same as the carboxylic acid used for the modification of the above-mentioned carboxylic acid-modified polyolefin.

Among these resin components, polyolefins such as polypropylene, and carboxylic acid-modified polyolefins are preferred; and polypropylene and acid-modified polypropylene are more preferred.

The heat-fusible resin layer 4 may be formed from one type of resin component alone, or may be formed from a blended polymer in which two or more types of resin components are combined. In addition, the heat-fusible resin layer 4 may be formed by only one layer, or may be formed by two or more layers using the same or different resin components.

From the viewpoint of suppressing an increase in the thickness of the battery packaging material and imparting high impact resistance, the heat-fusible resin layer 4 is preferably composed of unstretched polypropylene. From the same viewpoint, it is particularly preferable that the adhesive layer 5 to be described later is formed of a cured product of a polyurethane-based adhesive having a thickness of about 1 to 5 μm, and the heat-fusible resin layer 4 is formed of an unstretched polymer of a thickness of about 20 to 80 μm. Made of acrylic.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, it is preferable that a lubricant is attached to the surface of the heat-fusible resin layer 4 . The lubricant is not particularly limited, but an amide-based lubricant is preferably used. Specific examples of the amide-based lubricant include the aforementioned compounds.

When a lubricant exists on the surface of the heat-fusible resin layer 4, the amount of the lubricant is not particularly limited, but in an environment with a temperature of 24°C and a relative humidity of 60%, it is preferably about 3 mg/m ² or more, more preferably 4 to It is about 15 mg/m ² , more preferably about 5 to 14 mg/m ² .

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as it can function as a heat-fusible resin layer, but is preferably about 100 μm or less, more preferably about 15 to 100 μm, and even more preferably about 15 to 80 μm.

[Adhesive layer 5]

In the battery packaging material of the present invention, the adhesive layer 5 is a layer provided therebetween as necessary in order to firmly adhere the barrier layer 3 and the heat-fusible resin layer 4 .

The adhesive layer 5 is formed of resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4 to each other. As the resin for forming the adhesive layer 5 , the same adhesives as those exemplified in the adhesive layer 2 can be used, such as the adhesive mechanism, the type of the adhesive component, and the like. In addition, as the resin for forming the adhesive layer 5, polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified for the above-mentioned heat-fusible resin layer 4 can also be used and other polyolefin resins. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, as the polyolefin, a carboxylic acid-modified polyolefin is preferable, and a carboxylic acid-modified polypropylene is particularly preferable. That is, the resin constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, but preferably contains a polyolefin skeleton. The resin constituting the adhesive layer 5 contains a polyolefin skeleton and can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of the wavenumber of 1760 cm ^-1 and the vicinity of the wavenumber of 1780 cm ^-1 . However, when the acid modification degree is low, the peak becomes small and cannot be detected in some cases. In this case, analysis can be performed by nuclear magnetic resonance spectroscopy.

Furthermore, the adhesive layer 5 may be a resin containing an acid-modified polyolefin and a curing agent from the viewpoint of reducing the thickness of the battery packaging material and obtaining a battery packaging material excellent in shape stability after molding. The cured product of the composition. As the acid-modified polyolefin, the same examples as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-fusible resin layer 4 can be preferably exemplified.

Moreover, as a hardening|curing agent, if it can harden an acid-modified polyolefin, it will not specifically limit. Examples of the curing agent include epoxy-based curing agents, polyfunctional isocyanate-based curing agents, carbodiimide-based curing agents, and oxazoline-based curing agents.

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of epoxy-based curing agents include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerol polyglycidyl ether, and polyglycerol polyglycidyl ether. .

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), Their polymerized or nurate products, their mixtures, copolymers with other polymers, and the like.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N=C=N-). As a carbodiimide type hardening|curing agent, the polycarbodiimide compound which has at least 2 or more carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline-based curing agent include Epocros series manufactured by Nippon Shokubai Corporation.

From the viewpoint of improving the adhesiveness between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5 , or the like, the curing agent may be composed of two or more kinds of compounds.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50 mass %, more preferably in the range of about 0.1 to 30 mass %, and further preferably in the range of about 0.1 to 10 mass %.

The thickness of the adhesive layer 5 is not particularly limited as long as it can function as an adhesive layer, and when the adhesives exemplified for the adhesive layer 2 are used, it is preferably about 1 to 10 μm, and more preferably 1 to 10 μm. 5μm or so. Moreover, when using the resin exemplified by the heat-fusible resin layer 4, about 2-50 micrometers is preferable, and about 10-40 micrometers is more preferable. In addition, in the case of a cured product of an acid-modified polyolefin and a curing agent, it is preferably 30 μm or less, more preferably about 0.1 to 20 μm, and further preferably about 0.5 to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

3. Manufacturing method of battery packaging material

The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate in which each layer of a predetermined composition is laminated can be obtained. That is, a layer having at least the polyamide resin layer 1a, the adhesive resin layer 1b and the polyester resin layer 1c in this order is prepared as the base material layer 1, and the base material layer 1, the barrier layer 3 and the heat-fusible resin layer 4 are laminated, Thus, the battery packaging material of the present invention can be obtained.

An example of the manufacturing method of the battery packaging material of this invention is as follows. First, a laminate in which the base material layer 1 , the adhesive layer 2 provided as needed, and the barrier layer 3 are laminated in this order is formed (hereinafter, sometimes referred to as "laminate A"). Specifically, the formation of the laminate A can be carried out by a dry lamination method in which the base material layer 1 or, if necessary, the surface of which is chemically treated by a coating method such as a gravure coating method or a roll coating method. An adhesive for forming the adhesive layer 2 is applied on the barrier layer 3 , and after drying, the barrier layer 3 or the base material layer 1 is laminated, and the adhesive layer 2 is cured.

Next, the thermally fusible resin layer 4 is laminated on the barrier layer 3 of the laminate A. When directly laminating the heat-sealing resin layer 4 on the barrier layer 3, the resin component constituting the heat-sealing resin layer 4 may be applied on the barrier layer 3 of the laminate A by a gravure coating method, a roll coating method, or the like. That's it. In addition, when the adhesive layer 5 is provided between the barrier layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer 4 are co-extruded and laminated on the The method on the barrier layer 3 of the layer body A (co-extrusion lamination method); (2) A laminate in which the adhesive layer 5 and the thermal fusion resin layer 4 are laminated separately is formed, and the thermal lamination method is used to laminate the laminate. A method of laminating it on the barrier layer 3 of the laminate A; (3) on the barrier layer 3 of the laminate A, applying an adhesive for forming the adhesive layer 5 by extrusion or a solution, After drying at a high temperature, they are laminated by a sintering method or the like, and a preliminarily sheet-like heat-fusible resin layer 4 is laminated on the adhesive layer 5 by a thermal lamination method; Between the barrier layer 3 of the layer body A and the heat-fusible resin layer 4 preliminarily formed into a sheet shape, the laminated body A and the heat-fusible resin layer 4 are connected by the adhesive layer 5 while the molten adhesive layer 5 flows. The bonding method (sandwich lamination method), etc.

By the above-mentioned operations, a base material layer 1 / an adhesive layer 2 provided as needed / a barrier layer 3 whose surface is chemically treated as needed / an adhesive layer 5 provided as needed / a heat-fusible resin layer 4 are formed In order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed, the laminated body can be further applied to a hot roller contact type, a hot air type, a near-infrared type or a far-infrared type, etc. heat treatment. As conditions for such a heat treatment, for example, heating at 150° C. to 250° C. for 1 minute to 5 minutes is mentioned.

In the battery packaging material of the present invention, in order to improve or stabilize the suitability for film forming, lamination processing, secondary processing (bag making, embossing) of the final product, etc., each of the components constituting the laminate is The layer may be subjected to surface activation treatment such as corona treatment, sand blast treatment, oxidation treatment, and ozone treatment as required.

4. Use of packaging materials for batteries

The battery packaging material of the present invention is used in a package for sealing and accommodating battery elements such as positive electrodes, negative electrodes, and electrolytes. That is, a battery can be formed by accommodating a battery element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the battery packaging material of the present invention.

Specifically, using the battery packaging material of the present invention, a battery element including at least a positive electrode, a negative electrode, and an electrolyte can be formed with protrusions on the periphery of the battery element in a state where metal terminals connected to the positive electrode and the negative electrode, respectively, protrude outward. It is possible to provide a battery using a battery packaging material by covering the flange portion (region where the heat-sealing resin layers contact each other) and heat-sealing the heat-sealing resin layers of the flange portion to each other. However, when the battery element is housed in the package formed of the battery packaging material of the present invention, the package is formed so that the heat-fusible resin portion of the battery packaging material of the present invention is on the inner side (surface in contact with the battery element).

The battery packaging material of the present invention can be used in both primary batteries and secondary batteries, and is preferably a secondary battery. The type of secondary battery to which the battery packaging material of the present invention is applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, lead storage batteries, nickel-hydrogen storage batteries, nickel-cadmium storage batteries, nickel-iron storage batteries Batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, multivalent cation batteries, condensers, capacitors, etc. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are exemplified as preferable application objects of the battery packaging material of the present invention.

Example

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the Examples.

(Example 1-8 and Comparative Example 1-10)

<Manufacture of battery packaging materials>

The base material layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated to have the laminated structure described in Table 1, and a battery packaging material was produced. However, in the laminated structure shown in Table 1, the numerical value refers to the thickness (μm) of each layer, for example, "PET5" refers to polyethylene terephthalate having a thickness of 5 μm. In Table 1, PET refers to polyethylene terephthalate, AD refers to adhesive resin layer, ONY refers to stretched nylon, and in the lamination process, DL refers to a layer formed by dry lamination. Adhesive layer or adhesive layer, ALM refers to aluminum foil, PP refers to polypropylene, CPP refers to unstretched polypropylene, PPa refers to maleic anhydride modified polypropylene, and PEN refers to polyethylene naphthalate ester.

First, an aluminum foil (thickness 40 μm) as a barrier layer was laminated on the base material layer by a dry lamination method. Specifically, a two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the barrier layer on which the acid-resistant film was formed, and an adhesive layer (thickness 3 μm) was formed on the aluminum foil. ). Next, after laminating the adhesive layer on the barrier layer and the polyamide resin layer side of the base layer by a dry lamination method, an aging treatment was performed to produce a substrate layer/adhesive layer/barrier layer. laminate.

Next, in Examples 1, 3, 5, 7 and Comparative Examples 1, 3, 5, 7, and 9, maleic anhydride-modified polypropylene as an adhesive layer and polypropylene as a heat-fusible resin layer were melted Co-extrusion is carried out on the barrier layer (acid-resistant coating film) of each obtained laminate, whereby an adhesive layer and a heat-fusible resin layer are laminated on the surface of the barrier layer to obtain a base material layer/adhesive layer A battery packaging material in which /barrier layer/adhesive layer/heat-fusible resin layer are laminated in this order.

On the other hand, in Examples 2, 4, 6, and 8 and Comparative Examples 2, 4, 6, 8, and 10, in each of the laminates of the base material layer/adhesive layer/barrier layer obtained above, the A two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound) was applied on the barrier layer (acid-resistant film), and an adhesive layer (thickness 3 μm) was formed on the aluminum foil. Next, after laminating the adhesive layer on the barrier layer and the unstretched polypropylene by a dry lamination method, an aging treatment was performed to obtain a base material layer/adhesive layer/barrier layer/adhesive layer/ A battery packaging material in which thermally fusible resin layers are sequentially laminated.

<Evaluation of Electrolyte Resistance>

Each battery packaging material obtained above was cut out to prepare a test piece of 100 mm×100 mm, which was used as a test sample. In an environment of room temperature (25°C), an electrolytic solution (ethylene carbonate:diethylcarbonate:dimethylcarbonate=1:1:1 (volume ratio) was dropped onto the surface of the test sample on the side of the base material layer. 0.1 g of lithium hexafluorophosphate was added in 1 mol, and left as it was for 1 hour. After that, the electrolyte solution was wiped off with a waste cloth, and it was visually observed whether or not whitening occurred on the surface of the base material layer. The case where whitening did not occur was determined as A, and the case where whitening occurred was determined as C. The results are shown in Table 1.

<Number of layers>

In the manufacture of the above-mentioned battery packaging material, Table 1 shows the number of laminations of the respective layers. In Examples 1, 3, 5, 7 and Comparative Examples 1, 3, 5, 7, and 9, the following two lamination steps were performed: lamination by dry lamination between the base material layer and the barrier layer The lamination process and the lamination process of the adhesive layer and the heat-fusible resin layer by melt coextrusion of the normal barrier layer. In addition, in Examples 2, 4, 6, and 8 and Comparative Examples 2, 4, 6, and 8, the following two lamination steps were performed: lamination by dry lamination between the base material layer and the barrier layer. A layering process, and a lamination process by a dry lamination method between the barrier layer and the unstretched polypropylene film.

<Measurement of impact strength (J)>

The impact strength (J) of each battery packaging material obtained above was measured from the base material layer side in accordance with ASTM D3420. Among them, as a measuring device, a film impact tester manufactured by Toyo Seiki was used, and a tip hemispherical impact tip having a smooth surface with a radius of 12.7 mm was used. Here, in the measurement of the impact strength, a sample cut out with a diameter of 100 mm was used. The sample was fixed between two plates having a circular opening with a diameter of 89±0.5 mm in the center. Each sample was measured three times, and the average value was taken as the impact strength of each sample. The measurement was performed in an environment with a temperature of 23±2°C and a relative humidity of 50±5%. The results are shown in Table 1.

<Measurement of layer thickness of laminate>

The total thickness of the laminate constituting each battery packaging material obtained above was measured using a micrometer manufactured by Mitutoyo. The results are shown in Table 1. The value (J/μm) obtained by dividing the impact strength measured by the method described above by the thickness (μm) of each laminate is shown in Table 1.

[Table 1]

From the results shown in Table 1, it can be seen that the battery packaging materials of Examples 1 to 8 have high impact resistance and electrolyte resistance, and the base material layers of the battery packaging materials of Examples 1 to 8 are from the barrier layer side. It has a polyamide resin layer, an adhesive resin layer and a polyester resin layer in this order, the thickness of the polyester resin layer is 6 μm or less, and the impact strength ( The value obtained by dividing J) by the thickness (μm) of the laminate is 0.015 J/μm or more.

In addition, in Comparative Examples 6 and 8 with relatively large thicknesses, the impact strength also had a large value, but in Examples 3, 4, 7, and 8 having the same thickness, compared with Comparative Examples 6 and 8 , with greater impact strength.

<Measurement of hardness of each layer in Example 4>

As the apparatus, a nanoindenter ("TriboIndenter TI950" manufactured by HYSITRON) was used. As the indenter of the nanoindenter, a Berkovich indenter (triangular cone) was used. First, at a relative humidity of 50%, In an environment of 23°C, the pressure head was in contact with the surface of the adhesive layer of the battery packaging material (the surface where the adhesive layer was exposed, the direction perpendicular to the stacking direction of each layer), and the pressure was pressed for 10 seconds. The head was pressed into the adhesive layer from the surface to a load of 40 μN, kept in this state for 5 seconds, and then the load was released for 10 seconds. Using the maximum load _Pmax (μN) and the contact projected area A (μm ² ), and the indentation hardness (MPa) was calculated using P _max /A. The measurement position was changed, five positions were measured, and the average value was used. The hardness of the adhesive resin layer was the same as that of the adhesive layer except that the load was 10 μN. In addition, the hardness of the polyethylene terephthalate film and the stretched nylon film as the base layer were measured in the same manner except that the load was set to 100 μN under the above measurement conditions, respectively. Each hardness is shown in Table 2. Here, the surface of the indenter is a cross-section exposing the measurement object (adhesive layer, etc.) obtained by cutting in the thickness direction so as to pass through the center of the battery packaging material The cutting is performed using a commercially available rotary microtome or the like.

<Evaluation of formability>

The battery packaging material of the above-mentioned Example 4 was cut into a rectangle of length (x direction) 90 mm×width (y direction) 150 mm, and used as a test sample. For this sample, a rectangular molding die (female die, JIS B 0659-1:2002 Attached Document 1 (reference) surface roughness for comparison) having a diameter of 31.6 mm (x direction) × 54.5 mm (y direction) was used for the surface. The maximum height roughness (nominal value of Rz) specified in Table 2 of the standard sheet is 3.2 μm. Corner R 2.0 mm, ridge line R 1.0 mm), and the corresponding mold (male mold, surface JIS B 0659) -1: 2002 Attached Document 1 (Reference) The maximum height roughness (nominal value of Rz) specified in Table 2 of the surface roughness standard sheet for comparison is 1.6 μm. Corner R2.0mm, ridgeline R1.0mm), from From a molding depth of 0.5 mm, the molding depth was changed in units of 0.5 mm, and cold rolling was performed on each of 10 samples at a pressing pressure (surface pressure) of 0.25 MPa (one-stage molding was introduced). At this time, the above-mentioned test sample was placed on the female mold and molded so that the heat-fusible resin layer side was positioned on the male mold side. In addition, the gap between the male mold and the female mold was 0.3 mm. For the samples after cold rolling, light was irradiated with a pen torch in a dark room, and whether pinholes or cracks had occurred in the aluminum foil were confirmed by light transmission. In all 10 samples, the deepest molding depth at which pinholes and cracks did not occur in the aluminum foil were set as Amm, and the number of samples with pinholes and the like occurred among the shallowest molding depths where pinholes and the like occurred in the aluminum foil were set as B pieces. , and the value calculated by the following formula was used as the limit molding depth of the battery packaging material. The results are shown in Table 2.

Limit forming depth=Amm+(0.5mm/10pcs)×(10pcs-Bpcs)

[Table 2]

Symbol Description

1 substrate layer

1a Polyamide resin layer

1b Adhesive resin layer

1c polyester resin layer

2 Adhesive layer

3 barrier layers

4 Thermal fusion resin layer

5 Adhesive layer

10 Packaging materials for batteries

Claims (9)

1. A packaging material for a battery, characterized in that:

comprising a laminate comprising at least a base material layer, a barrier layer and a heat-sealable resin layer in this order,

the base material layer at least comprises a polyamide resin layer, an adhesive resin layer and a polyester resin layer in sequence from the side of the barrier layer,

the thickness of the polyester resin layer is 6 μm or less,

the laminate has a value of 0.015J/μm or more obtained by dividing the impact strength of the laminate measured from the base material layer side by the thickness of the laminate, in accordance with the specification of ASTM D3420.

2. The packaging material for batteries according to claim 1, wherein:

an adhesive layer is provided between the base material layer and the barrier layer,

the adhesive resin layer and the adhesive layer each have a hardness of 50MPa or less as measured by a nanoindentation method.

3. The packaging material for batteries according to claim 1 or 2, wherein:

the adhesive resin layer is formed of at least 1 selected from the group consisting of an acid-modified polyolefin-based resin, an acid-modified styrene-based elastomer resin, and an acid-modified polyester-based elastomer resin.

4. The packaging material for a battery according to any one of claims 1 to 3, wherein:

the heat-fusible resin layer is composed of unstretched polypropylene.

5. The packaging material for a battery according to any one of claims 1 to 4, wherein:

the ratio of the thickness of the polyester resin layer to the thickness of the polyamide resin layer is 0.5 or less.

6. The packaging material for a battery according to any one of claims 1 to 5, wherein:

the thickness of the laminate is 180 μm or less.

7. The packaging material for a battery according to any one of claims 1 to 6, wherein:

the polyamide resin layer is made of nylon.

8. The packaging material for a battery according to any one of claims 1 to 7, wherein:

the polyester resin layer is composed of polyethylene terephthalate.

9. A battery, characterized by:

a battery element having at least a positive electrode, a negative electrode and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 8.

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