JPWO2019031611A1 - Battery packaging material, battery, manufacturing method thereof, and method for improving printability of battery packaging material with ink - Google Patents

Abstract

At least, a substrate layer, a barrier layer, and a heat-fusible resin layer is formed of a laminate provided in this order,
At least, on the surface of the base material layer side of the laminate, a fatty acid amide compound is present,
A packaging material for a battery, wherein 1 g or more of the fatty acid amide compound dissolves in 100 g of methyl ethyl ketone in a 25° C. environment.

Description

The present invention relates to a battery packaging material, a battery, a manufacturing method thereof, and a method of improving printability of a battery packaging material with an ink.

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material has become an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used for battery packaging, but in recent years, as electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc. have become more sophisticated, batteries are required to have various shapes. At the same time, it is required to be thinner and lighter. However, the metal battery packaging materials that have been widely used conventionally have the drawbacks that it is difficult to follow the diversification of the shapes, and there is a limit to the weight reduction.

Therefore, as a battery packaging material that can be easily processed into various shapes and can be made thin and lightweight, it is a film-like material in which a base material layer/adhesive layer/barrier layer/heat-fusible resin layer are sequentially laminated. A laminated body has been proposed (for example, see Patent Document 1). In such a film-like battery packaging material, the battery element can be sealed by making the heat-fusible resin layers face each other and heat-sealing the peripheral edge portions by heat sealing.

In various packaging materials composed of the above laminates, ink is printed on the surface of the base material layer to form barcodes, patterns, characters, etc. and adhered on the base material layer on the printed side. A method of printing on a packaging material (generally called medium printing) by a method of laminating an agent and a barrier layer is widely adopted. However, when such a printed surface is present between the base material layer and the barrier layer, the adhesion between the base material layer and the barrier layer is deteriorated, and delamination easily occurs between the layers. In particular, since a battery to which the battery packaging material is applied is required to have high safety, such a method of performing printing by intermediate printing is shunned in the battery packaging material. Therefore, conventionally, when a print such as a bar code is formed on a packaging material for a battery, a method in which a seal having the print formed thereon is generally attached to the surface of the base material layer is adopted.

JP, 2008-287971, A

However, if a seal with a print is attached to the surface of the base material layer, the thickness and weight of the battery packaging material increase. Therefore, the present inventors considered a method of printing by directly printing ink on the surface of the base material layer of the battery packaging material in consideration of the recent trend of further thinning and weight reduction of the battery packaging material. did.

As a method for printing by printing ink directly on the surface of the base material layer of the battery packaging material, for example, pad printing (also called tampo printing) and inkjet printing are known. Pad printing is the following printing method. First, ink is poured into the recess of the flat plate on which the pattern to be printed is etched. Next, the silicon pad is pressed against the concave portion to transfer the ink to the silicon pad. Next, the ink transferred to the surface of the silicon pad is transferred to the print target to form a print on the print target. In such pad printing, since the ink is transferred to the print target by using an elastic silicon pad, it is easy to print on the surface of the battery packaging material after molding, and the battery element can be used as the battery packaging material. It has the advantage that the battery can be printed after sealing. Further, it has the same advantage in inkjet printing.

However, as a result of studies by the present inventors, when ink is printed on the surface of the base material layer side of the battery packaging material, the ink is repelled on the surface of the base material layer side, the ink is difficult to fix, and the ink is It has become clear that there may be a void portion that is not formed.

Further, in the packaging material for a battery, in order to increase the volume energy density, a recess is generally formed by cold forming to increase the volume accommodated in the battery element. In recent years, it has been required to further increase the storage volume by deep drawing. However, if pinholes or cracks occur in the battery packaging material during molding, the electrolyte may penetrate into the barrier layer and form metal deposits, resulting in a short circuit. Therefore, the packaging material for batteries is required to have further excellent moldability.

Under such circumstances, the main object of the present invention is to provide a battery packaging material having both excellent printability and excellent moldability. Further, the present invention also aims to provide a method for producing the packaging material for a battery, a battery using the packaging material for a battery, a method for producing a battery, and a method for improving printability of a packaging material for a battery with ink. And

The present inventor has conducted extensive studies in order to solve the above problems. As a result, at least a base material layer, a barrier layer, and a heat-fusible resin layer is composed of a laminate provided in this order, at least on the surface of the base material layer side of the laminate, a fatty acid amide compound is present. Furthermore, it has been found that the battery packaging material in which the fatty acid amide compound dissolves 1 g or more in 100 g of methyl ethyl ketone in an environment of 25° C. has both excellent printability and excellent moldability. .. The present invention has been completed by further studies based on these findings.

That is, the present invention provides a battery packaging material and a battery having the following aspects.
Item 1. At least, a substrate layer, a barrier layer, and a heat-fusible resin layer is formed of a laminate provided in this order,
At least, on the surface of the layered product on the side of the base material layer, a fatty acid amide compound is present,
A packaging material for a battery, wherein 1 g or more of the fatty acid amide compound dissolves in 100 g of methyl ethyl ketone in a 25° C. environment.
Item 2. Item 2. The battery packaging material according to Item 1, wherein a fatty acid amide compound is present in an amount of 2.0 mg/m ² or more on the surface of the base material layer side of the laminate.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, which is used for printing an ink on the surface of the layered product on the side of the base material layer.
Item 4. Item 4. The battery packaging material according to Item 3, wherein the ink contains at least one selected from the group consisting of methyl ethyl ketone, acetone, isopropyl alcohol, and ethanol.
Item 5. Item 5. The battery packaging material according to any one of Items 1 to 4, wherein the surface of the base material layer has a wetting tension of 32 mN/m or more.
Item 6. The fatty acid amide compound is at least one selected from the group consisting of erucic acid amide, ethylenebisoleic acid amide, oleylstearic acid amide, stearyl oleic acid amide, stearyl erucic acid amide, oleic acid amide, and behenic acid amide. The packaging material for a battery according to any one of Items 1 to 5.
Item 7. Item 7. The battery packaging material according to any one of Items 1 to 6, wherein a fatty acid amide compound is present on the surface of the heat-fusible resin layer side.
Item 8. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package made of the battery packaging material according to any one of Items 1 to 7.
Item 9. Item 9. The battery according to Item 8, which has a printed portion on a surface of the packaging body on the side of the base material layer.
Item 10. Item 10. The battery according to Item 8 or 9, which has a printed portion made of an ink on a surface of the base material layer side of the package.
Item 11. At least, including a step of laminating the base material layer, the barrier layer, and the heat-fusible resin layer in this order,
At least a fatty acid amide compound is present on the surface of the base material layer side of the laminate,
The method for producing a packaging material for a battery, wherein the fatty acid amide compound is one that dissolves 1 g or more in 100 g of methyl ethyl ketone in an environment of 25°C.
Item 12. Item 12. The method for producing a battery packaging material according to Item 11, further comprising a step of subjecting at least one surface of the base material layer to corona treatment.
Item 13. In a package made of the battery packaging material according to any one of items 1 to 7, a step of housing a battery element having at least a positive electrode, a negative electrode, and an electrolyte,
A step of performing printing with ink on the surface of the base material layer side of the package,
A method of manufacturing a battery, comprising:
Item 14. At least 1 g is dissolved in 100 g of methyl ethyl ketone in a 25° C. environment on the surface of the packaging material for a battery, which is composed of a laminate having a base material layer, a barrier layer, and a heat-fusible resin layer in this order. The method for improving the printability of the ink for the surface of the base material layer side surface of the battery packaging material by allowing the fatty acid amide compound to exist.

According to the present invention, it is possible to provide a battery packaging material having both excellent printability and excellent moldability. Further, according to the present invention, there is provided a method for producing the battery packaging material, a battery using the battery packaging material, a method for producing the battery, and a method for improving the printability of the battery packaging material with ink. Can also

It is a schematic diagram which shows an example of the cross-section of the packaging material for batteries of this invention. It is a schematic diagram which shows an example of the cross-section of the packaging material for batteries of this invention. It is a schematic diagram which shows an example of the cross-section of the packaging material for batteries of this invention. It is a schematic diagram which shows an example of the cross-section of the packaging material for batteries of this invention. It is a schematic diagram for demonstrating the measuring method of seal strength. It is a schematic diagram for demonstrating the measuring method of seal strength. It is a schematic diagram for demonstrating the measuring method of seal strength. It is a schematic diagram for demonstrating the measuring method of logarithmic decrement rate (DELTA)E by rigid pendulum measurement. It is a schematic diagram for demonstrating the measuring method of seal strength. The temperature difference T ₁ and the temperature difference T ₂ in differential scanning calorimetry is a diagram schematically showing.

The battery packaging material of the present invention comprises at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order from a laminate, and at least on the surface of the base material layer side of the laminate. Is characterized in that a fatty acid amide compound is present, and the fatty acid amide compound dissolves in 1 g or more with respect to 100 g of methyl ethyl ketone in a 25° C. environment.

In addition, in this specification, the numerical range shown by "-" means "greater than or equal to" and "less than or equal to." For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less. Hereinafter, the battery packaging material of the present invention will be described in detail.

1. Laminated Structure of Battery Packaging Material As shown in FIG. 1, the battery packaging material of the present invention is composed of a laminate having at least a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in this order. Has been done. In the battery packaging material of the present invention, the base material layer 1 is the outermost layer side 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 heat-sealed to seal the battery element, thereby sealing the battery element.

In the battery packaging material 10 of the present invention, as shown in FIG. 2, an adhesive layer 2 is provided between the base material layer 1 and the barrier layer 3 as needed for the purpose of enhancing the adhesiveness between them. It may be. In addition, as shown in FIG. 3, the battery packaging material 10 of the present invention may be bonded between the barrier layer 3 and the heat-fusible resin layer 4 if necessary for the purpose of enhancing the adhesiveness between them. Layer 5 may be provided. Further, as shown in FIG. 4, a surface coating layer 6 may be formed on the surface of the base material layer 1 side.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited, but the battery packaging material is excellent in formability while reducing the thickness of the battery packaging material to increase the energy density of the battery. From this viewpoint, for example, it is about 180 μm or less, preferably about 150 μm or less, more preferably about 60 to 180 μm, still more preferably about 60 to 150 μm.

In the battery packaging material 10 of the present invention, the fatty acid amide compound is present on the surface of the base material layer 1 side. Furthermore, the fatty acid amide compound dissolves in an amount of 1 g or more with respect to 100 g of methyl ethyl ketone (MEK) in a 25° C. environment. In the battery packaging material of the present invention, the presence of the fatty acid amide compound having such a specific solubility on the surface of the base material layer 1 side exerts excellent printability and excellent moldability. You can The details of this mechanism are considered as follows. That is, the presence of the fatty acid amide compound on the surface of the base material layer 1 improves the slipperiness between the surface of the base material layer and the molding die, and when the die is formed by drawing, Since the battery packaging material is easily drawn in, deep drawing can be performed, and it is considered that pinholes and tears are less likely to occur. Furthermore, since the fatty acid amide compound is dissolved in a specific amount of methyl ethyl ketone in a specific solvent, when the surface of the base material layer 1 side is printed by, for example, inkjet printing, the solvent contained in the ink It is considered that the fatty acid amide compound dissolves in the ink, and the fixation of the dye or pigment contained in the ink on the surface of the base material layer 1 side is less likely to be hindered by the fatty acid amide compound, resulting in excellent printability. To be

That is, according to the present invention, at least the surface of the base material layer 1 side of the packaging material for a battery, which is a laminate including the base material layer 1, the barrier layer 3, and the heat-fusible resin layer 4 in this order, has a 25° C. environment. It is possible to provide a method of improving the printability of the battery on the surface of the base material layer 1 side of the packaging material for a battery by allowing a fatty acid amide compound to be dissolved in 100 g of methyl ethyl ketone in 100 g. That is, a fatty acid amide compound having a property of dissolving 1 g or more in 100 g of methyl ethyl ketone in a 25° C. environment is present on the surface of the base material layer 1 side of the battery packaging material of the present invention.

In the present invention, from the viewpoint of achieving both excellent printability and excellent moldability, the lower limit of the amount of the fatty acid amide compound present on the surface of the base material layer 1 side is preferably about 2.0 mg/m ² or more. , More preferably about 4.0 mg/m ² or more, more preferably about 5.0 mg/m ² or more, more preferably about 6.5 mg/m ² or more, further preferably about 7.0 mg/m ² or more. is, the upper limit is preferably about 20.0 mg / m ² or less, more preferably about 15.0 mg / m ² or less, more preferably 14.5 mg / m ² or less, more preferably 14.0 mg / m ² or less and examples of the preferred range, 2.0~20.0mg / m ² approximately, 2.0~15.0mg / m ² approximately, 2.0~14.5mg / m ² approximately, 2.0 to 14 About 0.0 mg/m ^2, about 4.0-20.0 mg/m ^2, about 4.0-15.0 mg/m ^2, about 4.0-14.5 mg/m ^2, about 4.0-14.0 mg /M ^2, about 5.0 to 20.0 mg/m ^2, about 5.0 to 15.0 mg/m ^2, about 5.0 to 14.5 mg/m ^2, about 5.0 to 14.0 mg/m ^{About 2}
6.5~20.0mg / m ² approximately, 6.5~15.0mg / m ² approximately, 6.5~14.5mg / m ² approximately, 6.5~14.0mg / m ² approximately, 7. 0 to 20.0 mg/m ^2, about 7.0 to 15.0 mg/m ^2, about 7.0 to 14.5 mg/m ^2, about 7.0 to 14.0 mg/m ² .

It should be noted that if the amount of the fatty acid amide compound present on the surface of the base material layer 1 side of the battery packaging material is too large, the fatty acid amide compound adheres to the mold at the time of molding and becomes a lump to contaminate the mold. There may be problems. If another battery packaging material is molded while the mold is contaminated, the lumps of fatty acid amide compound attached to the mold will adhere to the surface of the battery packaging material, and the heat-fusible resin layer will be heat-sealed as it is. Be offered to. Then, when the heat-fusible resin layer is heat-sealed, the portion to which the fatty acid amide compound adheres becomes non-uniformly melted, resulting in poor sealing. In order to prevent this, it is necessary to increase the cleaning frequency for removing the fatty acid amide compound attached to the mold, which may cause a problem that the continuous productivity of the battery is reduced. In the battery packaging material of the present invention, when the amount of the fatty acid amide compound present on the surface of the base material layer 1 side is within the above range, the continuous productivity of the battery can be effectively enhanced.

From the same viewpoint, the amount of the fatty acid amide compound dissolved in 100 g of methyl ethyl ketone in a 25° C. environment is preferably about 1 to 16 g, more preferably about 1 to 14 g, and further preferably about 5 to 12 g.

The fatty acid amide compound that dissolves in 1 g or more with respect to 100 g of methyl ethyl ketone in a 25° C. environment is not particularly limited, but preferably erucic acid amide, ethylenebisoleic acid amide, oleyl stearic acid amide, stearyl oleic acid amide, stearyl. Examples thereof include erucic acid amide, oleic acid amide, and behenic acid amide. As the fatty acid amide compound, only one kind may be used, or two or more kinds may be mixed and used. The amount of the fatty acid amide compound dissolved in 100 g of methyl ethyl ketone was determined by gradually adding the fatty acid amide compound to 100 g of methyl ethyl ketone stirred with a stirrer in a 25° C. environment and measuring the maximum dissolved amount. I can confirm. More specifically, 1.0 g of the fatty acid amide compound is added to 100 g of methyl ethyl ketone at 25° C., sufficiently stirred with a stirrer, and then allowed to stand. When the undissolved residue cannot be visually confirmed in the obtained solution, 1.0 g of the fatty acid amide compound is further added, and each time the mixture is sufficiently stirred with a stirrer. When the undissolved fatty acid amide compound can be confirmed in the solution, 2.0 g of the fatty acid amide compound is further added, and the mixture is left to stir with a stirrer. With the undissolved residue settled, the supernatant is sampled and the concentration of the fatty acid amide compound in the solution is quantified by high performance liquid chromatography (HPLC) to obtain the amount of the fatty acid amide compound dissolved in 100 g of methyl ethyl ketone. Quantification is performed by creating a calibration curve and interpolating.

The amount of the fatty acid amide compound present on the surface of the base material layer 1 side of the battery packaging material is determined by rinsing a predetermined area of the surface of the base material layer 1 side with an organic solvent to determine the amount of the fatty acid amide compound contained in the obtained cleaning liquid. The amount can be quantified using a gas chromatography mass spectrometer (GC-MS).

In the battery packaging material of the present invention, the wettability of the surface of the base material layer 1 side is preferably about 32 mN/m or more, more preferably 35 to 46 mN, from the viewpoint of improving printability while improving moldability. /M, more preferably about 36 to 44 mN/m. In addition, in this invention, the wetting tension of the packaging material for batteries is a value measured by the method based on the regulation of JIS K6768:1999, and the specific method is as described in the Examples.

INDUSTRIAL APPLICABILITY The battery packaging material of the present invention can be suitably used for applications in which the surface of the laminate on the base material layer 1 side is printed with ink. As the printing with the ink, for example, the above-mentioned pad printing, inkjet printing and the like are suitable, and inkjet printing is particularly suitable. The solvent contained in the ink preferably includes methyl ethyl ketone, acetone, isopropyl alcohol, ethanol and the like. The solvent may be used alone or in combination of two or more.

A printed portion may be formed on the surface of the packaging material for a battery of the present invention on the side of the base material layer 1. In the present invention, the printing portion is a portion where printing is performed. The print includes, for example, a barcode, a pattern, characters, etc., and the print shape is not limited. The method of forming the printing portion is not particularly limited, and the printing portion can be formed by printing with ink, and further by using a pen or the like using ink. When the battery packaging material of the present invention has a printed portion, the printed portion is preferably a printed portion on which a print is formed by printing ink. That is, it is preferable that the battery packaging material of the present invention has an ink printed portion on the surface of the base material layer 1 side.

Furthermore, in the battery packaging material of the present invention, with the heat-fusible resin layers 4 facing each other, a metal plate having a width of 7 mm was used, and the temperature was 190° C. at a temperature of 190° C. in the stacking direction from both sides of the test sample. The heat-fusible resin layers 4 are heat-fused to each other by heating and pressurizing under a condition of a pressure of 2.0 MPa and a time of 3 seconds (see FIGS. 5 and 6), and then, as shown in FIG. In the environment of a temperature of 140° C., a tensile speed of 300 mm/min, a peeling angle of 180°, and a chuck distance of 50 mm, the tensile strength measurement was started for 1.5 seconds from the start of tensile strength measurement. During this period, the maximum value of the tensile strength (seal strength) measured by peeling off the heat-sealed interface is preferably 3.0 N/15 mm or more, and more preferably 4.0 N/15 mm or more. The upper limit of the tensile strength is, for example, about 5.0 N/15 mm or less, and a preferable range is 3.0 to 5.0 N/15 mm, 4.0 to 5.0 N/15 mm. As described above, since the heat resistant temperature of the separator inside the battery is generally set to around 120 to 140° C., the tensile strength (seal strength) in the high temperature environment of 140° C. in the battery packaging material of the present invention. It is preferred that the maximum value of satisfies the above value. In order to set such tensile strength, for example, the type, composition, molecular weight, etc. of the resin forming the heat-fusible resin layer are adjusted.

As shown in Examples described later, the tensile test at each temperature is performed in a constant temperature bath, and the test sample is attached to the chuck in the constant temperature bath at a predetermined temperature (25°C or 140°C) for 2 minutes. Hold and then start the measurement.

Further, the battery packaging material of the present invention has an electrolyte (concentration of lithium hexafluorophosphate is 1 mol/l and volume ratio of ethylene carbonate, diethyl carbonate and dimethyl carbonate is 1:1 in an environment of 85° C.). 1) (a solution obtained by mixing ethylene carbonate, diethyl carbonate, and dimethyl carbonate at a volume ratio of 1:1:1) with the battery packaging material for 72 hours, and then performing the heat fusion. Heat-fusible resin layers are heat-fused under the conditions of a temperature of 190° C., a surface pressure of 2.0 MPa and a time of 3 seconds in a state where the electrolytic solution is attached to the surface of the heat-resistant resin layer, and the heat-fused interface The seal strength when peeling off is preferably 80% or more of the seal strength when not contacted with the electrolytic solution (the retention rate of the seal strength is 80% or more), and more preferably 90% or more. , 100% is more preferable.

(Method of measuring seal strength retention rate)
Using the seal strength before contact with the electrolytic solution measured by the following method (100%), the retention rate (%) of the seal strength after contacting with the electrolytic solution is calculated.

<Measurement of seal strength before contact with electrolyte>
In <Measurement of seal strength after contact with electrolytic solution> described below, the tensile strength (seal strength) is measured in the same manner except that the electrolytic solution is not injected into the test sample. The maximum tensile strength until the heat-sealed portion is completely peeled off is defined as the sealing strength before contact with the electrolytic solution.

<Measurement of seal strength after contact with electrolyte>
As shown in the schematic view of FIG. 9, a battery packaging material is cut into a rectangle having a width (x direction) of 100 mm×length (z direction) of 200 mm to obtain a test sample (FIG. 9 a ). The test sample is folded back at the center in the z direction so that the heat-fusible resin layer sides overlap (FIG. 9b). Next, both ends of the folded back test sample in the x direction are sealed by heat sealing (temperature 190° C., surface pressure 2.0 MPa, time 3 seconds), and formed into a bag shape having one opening E (FIG. 9c). Next, an electrolyte solution (concentration of lithium hexafluorophosphate is 1 mol/l and volume ratio of ethylene carbonate, diethyl carbonate and dimethyl carbonate is 1:1: 1) from the opening E of the bag-shaped test sample. 6 g of the solution of 1) is injected (FIG. 9d), and the end of the opening E is sealed by heat sealing (temperature 190° C., surface pressure 2.0 MPa, time 3 seconds) (FIG. 9e). Next, the folded back portion of the bag-shaped test sample is faced down, and the bag is allowed to stand in a temperature of 85° C. for a predetermined storage time (a time of contact with the electrolytic solution). Then, the end of the test sample is cut (FIG. 9e) and all the electrolyte is drained. Next, with the electrolytic solution adhered to the surface of the heat-fusible resin layer, the upper and lower surfaces of the test sample were sandwiched by metal plates (7 mm width), and the temperature was 190° C., the surface pressure was 1.0 MPa, and the conditions were 3 seconds. To heat-bond the heat-fusible resin layers to each other (FIG. 9f). Next, the test sample is cut into a width of 15 mm with a double-edged sample cutter so that the seal strength at a width (x direction) of 15 mm can be measured (FIGS. 9f and 9g). Next, using a tensile tester, a T-peel is peeled off at an environment of a temperature of 25° C., at a tensile speed of 300 mm/min, a peeling angle of 180°, and a chuck-to-chuck distance of 50 mm. Then, the tensile strength (seal strength) is measured (FIG. 7). The maximum tensile strength until the heat-sealed portion is completely peeled off is defined as the sealing strength after contact with the electrolytic solution.

2. Each layer forming the battery packaging material [base material layer 1]
In the battery packaging material 10 of the present invention, the base material layer 1 is a layer positioned on the outermost layer side. The material forming the base material layer 1 is not particularly limited as long as it has an insulating property. Examples of the material for forming the base material layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, polycarbonate, and a mixture or copolymer thereof. And so on. Among these, the base material layer 1 preferably has at least one of a layer formed of polyester and a layer formed of polyamide.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymerized polyesters containing ethylene terephthalate as the main repeating unit, and butylene terephthalate as the main repeating unit. Copolymerized polyester and the like can be mentioned. Further, as the copolymerized polyester containing ethylene terephthalate as a main unit of repeating units, specifically, a copolymer polyester polymerized with ethylene isophthalate having ethylene terephthalate as a main unit of repeating units (hereinafter, polyethylene (terephthalate/isophthalate)) Abbreviated), polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate) , Polyethylene (terephthalate/decanedicarboxylate) and the like. The copolymerized polyester containing butylene terephthalate as the main repeating unit is specifically a copolymer polyester that is polymerized with butylene terephthalate as the main repeating unit (hereinafter referred to as polybutylene (terephthalate/isophthalate)). Abbreviated), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), polybutylene (terephthalate/decanedicarboxylate), polybutylene naphthalate, and the like. These polyesters may be used alone or in combination of two or more. Polyester is excellent in electrolytic solution resistance and has an advantage that whitening or the like is unlikely to occur due to the adhesion of the electrolytic solution, and is preferably used as a material for forming the base material layer 1.

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; terephthalic acid and/or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides such as Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid), etc. A polyamide containing an aromatic compound such as pamide (MXD6); an alicyclic polyamide such as polyaminomethylcyclohexyl adipamide (PACM6); and a copolymer of a lactam component and an isocyanate component such as 4,4′-diphenylmethane-diisocyanate. Examples thereof include a polyamide, a polyesteramide copolymer or a polyetheresteramide copolymer which is a copolymer of a copolyamide and a polyester or a polyalkylene ether glycol; and a copolymer thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film is excellent in stretchability, can prevent whitening due to resin cracking of the base material layer 1 during molding, and is suitably used as a material for forming the base material layer 1.

The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, especially a biaxially stretched resin film has improved heat resistance due to oriented crystallization, and is therefore preferably used as the base material layer 1. In addition, the base material layer 1 may be formed by coating the above-mentioned materials on the barrier layer 3.

Among these, the resin film forming the base material layer 1 is preferably nylon or polyester, more preferably biaxially stretched nylon, or biaxially stretched polyester, particularly preferably biaxially stretched nylon.

The base material layer 1 may be formed by laminating (multilayered structure) at least one of a resin film and a coating made of different materials in order to improve pinhole resistance and insulation when used as a battery package. is there. Specific examples thereof include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of polyester films are laminated. When the base material layer 1 has a multilayer structure, a laminate of a biaxially oriented nylon film and a biaxially oriented polyester film, a laminate of a plurality of biaxially oriented nylon films, and a laminate of a plurality of biaxially oriented polyester films. The body is preferred. For example, when the base material layer 1 is formed of two layers of resin film, a constitution in which a polyester resin and a polyester resin are laminated, a constitution in which a polyamide resin and a polyamide resin are laminated, or a constitution in which a polyester resin and a polyamide resin are laminated Is preferable, and a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a structure in which nylon and nylon are laminated, or a structure in which polyethylene terephthalate and nylon are laminated are more preferable. In addition, since biaxially stretched polyester is unlikely to discolor when an electrolytic solution adheres to the surface, for example, when the base material layer 1 has a multilayer structure of a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film. The base material layer 1 is preferably a laminate having biaxially stretched nylon and biaxially stretched polyester in this order from the barrier layer 3 side. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably about 3 to 25 μm.

When the base material layer 1 has a multi-layer structure, the resin films may be adhered via an adhesive or may be directly laminated without an adhesive. In the case of adhering without an adhesive, for example, a coextrusion laminating method, a sandwich laminating method, a thermal laminating method, or the like may be used. When the adhesive is used to bond the adhesive, the adhesive used may be a two-component curing type adhesive or a one-component curing type adhesive. Further, the adhesion mechanism of the adhesive is not particularly limited, and may be any of chemical reaction type, solvent volatilization type, heat melting type, heat pressure type, electron beam curing type, ultraviolet curing type and the like. Specific examples of the adhesive include the same adhesives as those exemplified for the adhesive layer 2 described later. Further, the thickness of the adhesive may be the same as that of the adhesive layer 2.

The surface on the base material layer 1 side may be a corona-treated surface. Since the surface of the base material layer 1 side is corona-treated, the printability of the surface of the base material layer 1 can be improved. The conditions for the corona treatment are not particularly limited. For example, by treating the surface of the base material layer 1 side at a speed of 10 m/min with an irradiation output of 1 Kw or more, the wetting tension of the base material layer 1 side surface can be increased.

The thickness of the base material layer 1 is preferably 4 μm or more, more preferably about 10 to 75 μm, from the viewpoint of making the battery packaging material 10 excellent in moldability while reducing the thickness of the battery packaging material 10. And more preferably about 10 to 50 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 needed in order to firmly bond them.

The adhesive layer 2 is formed of an adhesive that can bond the base material layer 1 and the barrier layer 3 together. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive, a one-component curable adhesive, or a resin that does not undergo a curing reaction. Further, the adhesion mechanism of the adhesive used to form the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressing type and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; polyether. -Based adhesives; polyurethane-based adhesives; epoxy-based resins; phenolic resin-based resins; polyamide-based resins such as nylon 6, nylon 66, nylon 12 and copolyamides; polyolefins such as polyolefins, carboxylic acid-modified polyolefins, metal-modified polyolefins, etc. Resins, polyvinyl acetate resins; cellulosic adhesives; (meth)acrylic resins; polycarbonates; polyimide resins; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, styrene-butadiene rubber; Examples include silicone resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferable. In addition, the resin serving as the adhesive component may be used in combination with an appropriate curing agent to enhance the adhesive strength. The curing agent is appropriately selected from polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc. depending on the functional groups of the adhesive component.

Examples of the polyurethane adhesive include a polyurethane adhesive containing a base compound containing a polyol compound and a curing agent containing an isocyanate compound. Preferred is a two-component curing type polyurethane adhesive containing a polyol such as a polyester polyol, a polyether polyol and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Moreover, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group at the side chain in addition to the hydroxyl group at the terminal of the repeating unit. Since the adhesive layer 2 is formed of the polyurethane adhesive, excellent resistance to the electrolytic solution is imparted to the battery packaging material, and the base layer 1 is prevented from peeling off even when the electrolytic solution adheres to the side surface.

Further, the adhesive layer 2 may contain other components as long as it does not impair the adhesiveness, and may contain a colorant, a thermoplastic elastomer, a tackifier, a filler, or the like. Since the adhesive layer 2 contains the coloring agent, the battery packaging material can be colored. Known colorants such as pigments and dyes can be used as the colorant. Moreover, only one type of colorant may be used, or two or more types may be mixed and used.

The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, benzimidazolone-based pigments, etc. Examples of the pigment include carbon black pigments, titanium oxide pigments, cadmium pigments, lead pigments, chromium oxide pigments, iron pigments and the like, and mica (mica) fine powder, fish scale foil and the like.

Among the colorants, for example, carbon black is preferable in order to make the appearance of the battery packaging material black.

The average particle diameter of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured by a laser diffraction/scattering particle size distribution measuring device.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the battery packaging material is colored, and is, for example, about 5 to 60% by mass, preferably 10 to 40% by mass.

The thickness of the adhesive layer 2 is not particularly limited as long as it functions as an adhesive layer, but is, for example, about 1 to 10 μm, preferably about 2 to 5 μm.

[Barrier layer 3]
In the battery packaging material, the barrier layer 3 has a function of improving the strength of the battery packaging material and having a function of preventing water vapor, oxygen, light, and the like from entering the inside of the battery. The barrier layer 3 is preferably a metal layer, that is, a layer formed of a metal. Specific examples of the metal forming the barrier layer 3 include aluminum, stainless steel, titanium, and the like, and aluminum is preferable. The barrier layer 3 can be formed of, for example, a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, or the like. Is preferable, and it is more preferable to form the aluminum alloy foil. From the viewpoint of preventing wrinkles and pinholes from being generated in the barrier layer 3 during the production of the battery packaging material, the barrier layer is, for example, annealed aluminum (JIS H4160:1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O), etc., and it is more preferable to form with a soft aluminum alloy foil.

The thickness of the barrier layer 3 is not particularly limited as long as it functions as a barrier layer against water vapor and the like, but from the viewpoint of reducing the thickness of the battery packaging material, it is preferably about 100 μm or less, more preferably about 10 to 100 μm. And more preferably about 10 to 80 μm.

Further, it is preferable that at least one side, preferably both sides, of the barrier layer 3 is subjected to chemical conversion treatment in order to stabilize adhesion, prevent dissolution and corrosion. Here, the chemical conversion treatment means a treatment for forming an acid resistant film on the surface of the barrier layer. As the chemical conversion treatment, for example, chromate chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, acetyl acetate chromate, chromium chloride, potassium chromium sulfate, etc. A phosphoric acid treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4) And a chromate treatment using. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. Good.

In formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and each represents a hydroxy group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl group. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, and a 3-hydroxypropyl group. A straight or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group is substituted. An alkyl group is mentioned. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulas (1) to (4) is, for example, preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000. More preferable.

As a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, phosphoric acid is coated with a dispersion of metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide, or fine particles of barium sulfate, An example is a method of forming an acid resistant film on the surface of the barrier layer 3 by performing a baking treatment at 150° C. or higher. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid resistant film. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine Alternatively, derivatives thereof, aminophenol and the like can be mentioned. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. Examples of the cross-linking agent include compounds having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these cross-linking agents, only one kind may be used, or two or more kinds may be used in combination.

As a specific method for providing the acid-resistant coating, for example, as one example, at least the inner layer side of the aluminum alloy foil is firstly subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method. Degreasing treatment is performed by a well-known treatment method such as an acid activation method, and then the degreasing treatment surface is treated with a metal phosphate such as chromium phosphate, titanium phosphate, zirconium phosphate, zinc phosphate, or the like. Treatment liquid containing a mixture of metal salts as a main component (aqueous solution), treatment liquid containing a non-metal phosphate and a mixture of these non-metal salts as a main component, or these and an acrylic resin Or a phenolic resin or a urethane resin, a treatment liquid (aqueous solution) consisting of a mixture with an aqueous synthetic resin is applied by a well-known coating method such as a roll coating method, a gravure printing method or a dipping method to form an acid resistant film. Can be formed. For example, when treated with a chromium phosphate salt-based treatment liquid, it becomes an acid resistant film composed of chromium phosphate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc., and treated with a zinc phosphate salt-based treatment liquid. In this case, an acid resistant film made of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride or the like is obtained.

Further, as another example of the specific method of providing the acid resistant coating, for example, at least the surface on the inner layer side of the aluminum alloy foil is first subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid. By performing a degreasing treatment by a well-known treatment method such as an activation method, and then performing a well-known anodic oxidation treatment on the degreased surface, an acid resistant film can be formed.

Further, as another example of the acid resistant coating, a phosphate coating or a chromic acid coating may be mentioned. Examples of the phosphate type include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate, and examples of the chromic acid type include chromium chromate.

Further, as another example of the acid resistant film, by forming an acid resistant film of phosphate, chromate, fluoride, triazine thiol compound, etc., between the aluminum and the base material layer at the time of embossing molding. Delamination prevention, hydrogen fluoride generated by the reaction of electrolyte and water prevents dissolution and corrosion of aluminum surface, especially aluminum oxide present on the surface of aluminum, and prevents adhesion and adhesion of aluminum surface. It exhibits the effects of improving the property (wettability), preventing delamination between the base material layer and aluminum during heat sealing, and, in the embossed type, preventing delamination between the base material layer and aluminum during press molding. Among the substances that form an acid resistant film, an aqueous solution composed of three components of a phenol resin, a chromium (III) fluoride compound, and phosphoric acid is applied to the aluminum surface, and dry baking is preferable.

The acid-resistant coating includes a layer having cerium oxide, phosphoric acid or a phosphate, an anionic polymer, and a cross-linking agent that cross-links the anionic polymer, and the phosphoric acid or the phosphate is 1 to 100 parts by mass may be mixed with 100 parts by mass of cerium oxide. The acid resistant coating is preferably a multi-layer structure further including a layer having a cationic polymer and a crosslinking agent that crosslinks the cationic polymer.

Further, it is preferable that the anionic polymer is poly(meth)acrylic acid or a salt thereof, or a copolymer containing (meth)acrylic acid or a salt as a main component. Further, it is preferable that the cross-linking agent is at least one selected from the group consisting of a compound having a functional group of any one of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and a silane coupling agent.

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

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

Specific examples of the acid resistant coating include those containing at least one of phosphate, chromate, fluoride, and triazine thiol. An acid resistant coating containing a cerium compound is also preferable. The cerium compound is preferably cerium oxide.

Further, specific examples of the acid resistant coating include a phosphate coating, a chromate coating, a fluoride coating, a triazine thiol compound coating, and the like. As the acid resistant film, one kind of these may be used, or a combination of a plurality of kinds may be used. Further, as the acid resistant film, after degreasing the chemical conversion treatment surface of the aluminum alloy foil, a treatment liquid consisting of a mixture of a metal phosphate and an aqueous synthetic resin, or a mixture of a nonmetallic phosphate and an aqueous synthetic resin. It may be formed of a treatment liquid consisting of

The composition of the acid resistant film can be analyzed by, for example, time-of-flight secondary ion mass spectrometry. By analyzing the composition of the acid resistant coating using time-of-flight secondary ion mass spectrometry, for example, a peak derived from at least one of Ce ⁺ and Cr ⁺ is detected.

It is preferable that the surface of the aluminum alloy foil is provided with an acid resistant coating containing at least one element selected from the group consisting of phosphorus, chromium and cerium. It is confirmed by X-ray photoelectron spectroscopy that the acid-resistant coating on the surface of the aluminum alloy foil of the battery packaging material contains at least one element selected from the group consisting of phosphorus, chromium and cerium. can do. Specifically, first, in the battery packaging material, the heat-fusible resin layer, the adhesive layer, and the like laminated on the aluminum alloy foil are physically peeled off. Next, the aluminum alloy foil is put into an electric furnace and is heated at about 300° C. for about 30 minutes to remove the organic component existing on the surface of the aluminum alloy foil. Then, it is confirmed that these elements are contained by using X-ray photoelectron spectroscopy on the surface of the aluminum alloy foil.

The amount of the acid resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, when the above chromate treatment is performed, the chromium compound is chromium compound per 1 m ² of the surface of the barrier layer 3. Converted to about 0.5 to 50 mg, preferably about 1.0 to 40 mg, phosphorus compound converted to about 0.5 to 50 mg, preferably 1.0 to 40 mg, and aminated phenol polymer 1.0 to. It is desirable that the content is about 200 mg, preferably about 5.0 to 150 mg.

The thickness of the acid resistant film is not particularly limited, but from the viewpoint of the cohesive force of the film and the adhesion with the aluminum alloy foil or the heat-sealing resin layer, preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm. And more preferably about 1 to 50 nm. 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.

The chemical conversion treatment is carried out by applying a solution containing a compound used for forming an acid resistant film to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method or the like, and then the temperature of the barrier layer is 70 It is performed by heating so as to be about 200°C. In addition, before subjecting the barrier layer to the chemical conversion treatment, the barrier layer may be previously subjected to a 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, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer.

[The heat-fusible 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 that seals the battery element by heat-sealing the heat-fusible resin layers during assembly of the battery.

The resin component used in the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-bonded, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin forming the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. Further, when the resin forming the heat-fusible resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, polypropylene block copolymer (for example, propylene/ethylene block copolymer), polypropylene. Polypropylene, such as a random copolymer of (for example, a random copolymer of propylene and ethylene); an ethylene-butene-propylene terpolymer, and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, and isoprene. .. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Among these polyolefins, cyclic alkenes are preferable, and norbornene is more preferable. Styrene may also be used as a constituent monomer.

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

The acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of an α,β-unsaturated carboxylic acid or an anhydride thereof, or with respect to the cyclic polyolefin, α,β-. It is a polymer obtained by block-polymerizing or graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof. The cyclic polyolefin modified with carboxylic acid is the same as described above. The carboxylic acid used for modification is the same as that used for modifying the polyolefin.

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

The heat-fusible resin layer 4 may be formed of one type of resin component alone, or may be formed of a blend polymer in which two or more types of resin components are combined. Further, the heat-fusible resin layer 4 may be formed of only one layer, but may be formed of two or more layers with the same or different resin components.

A fatty acid amide compound may be present on the surface of the heat-fusible resin layer 4. The fatty acid amide compound is not particularly limited, and examples thereof include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylol amide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, and the like. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamide include methylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebisstearic acid amide. Examples thereof include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N′-distearyl adipic acid amide, and N,N′-distearyl sebacic acid amide. Specific examples of the unsaturated fatty acid bisamide include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N′-dioleyl adipic acid amide, and N,N′-dioleyl sebacic acid amide. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearylisophthalic acid amide and the like. The fatty acid amide compounds may be used alone or in combination of two or more.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as it exhibits the function as the heat-fusible resin layer, but is preferably about 60 μm or less, more preferably about 15 to 40 μm.

When the fatty acid amide compound is present on the surface of the heat-fusible resin layer 4, the amount of the fatty acid amide compound is not particularly limited, but is preferably 3 mg/m ² or more, more preferably at a temperature of 24° C. and a relative humidity of 60%. is 10 to 50 mg / m ² about, even more preferably include about 15~40mg / m ^2.

In the battery packaging material of the present invention, when the temperature difference T ₁ and the temperature difference T ₂ are measured by the following method, a value obtained by dividing the temperature difference T ₂ by the temperature difference T ₁ (ratio T ₂ /T ₁ ) is, for example, preferably 0.55 or more, and more preferably 0.60 or more. As will be understood from the measurement contents of the temperature differences T ₁ and T ₂ below, the closer the ratio T ₂ /T ₁ is to the upper limit of 1.0, the closer the heat-fusible resin layer comes into contact with the electrolytic solution. This means that the change in the width between the start point (extrapolated melting start temperature) and the end point (extrapolated melting end temperature) of the melting peak before and after is small (see the schematic diagram of FIG. 10 ). That is, the value of T ₂ is usually less than or equal to the value of T ₁ . A factor that causes a large change in the range of the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak is that the low molecular weight resin contained in the resin that constitutes the heat-fusible resin layer contacts the electrolytic solution. By eluting in the electrolytic solution, the width of the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak of the heat-fusible resin layer after contact with the electrolytic solution is Then, it becomes small. As one of the methods for reducing the change in the width of the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak, the proportion of low molecular weight resin contained in the resin constituting the heat-fusible resin layer There is a method of adjusting.

(Measurement of temperature difference T ₁ )
According to JIS K7121:2012, a differential scanning calorimetry (DSC) is used to obtain a DSC curve for the polypropylene used for the heat-fusible resin layer of each of the above battery packaging materials. From the obtained DSC curve, the temperature difference T ₁ between the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature of the heat-fusible resin layer is measured.

(Measurement of temperature difference T ₂ )
In an environment of a temperature of 85° C., polypropylene used for the heat-fusible resin layer was prepared by using lithium hexafluorophosphate at a concentration of 1 mol/l and a volume ratio of ethylene carbonate, diethyl carbonate and dimethyl carbonate of 1:1: After allowing it to stand in the electrolytic solution as the solution of No. 1 for 72 hours, it is sufficiently dried. Next, according to JIS K7121:2012, a differential scanning calorimetry (DSC) is used to obtain a DSC curve for the dried polypropylene. Next, the temperature difference T ₂ between the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature of the heat fusible resin layer after drying is measured from the obtained DSC curve.

In measuring the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature, a commercially available product can be used as the differential scanning calorimeter. As the DSC curve, after holding the test sample at -50°C for 10 minutes, the temperature was raised to 200°C at a temperature rising rate of 10°C/minute (first time), and held at 200°C for 10 minutes, and then the temperature lowering rate. The temperature was lowered to −50° C. at −10° C./min, the temperature was kept at −50° C. for 10 minutes, then the temperature was raised to 200° C. at a temperature rising rate of 10° C./min (second time), and the temperature was kept at 200° C. for 10 minutes. The DSC curve when heating up to 200° C. for the second time is used. In addition, when measuring the temperature difference T ₁ and the temperature difference T ₂ , in each DSC curve, of the melting peaks appearing in the range of 120 to 160° C., the melting peak with the largest difference in the input of heat energy is analyzed. To do. Even if there are two or more peaks that overlap each other, only the melting peak that maximizes the difference in input of heat energy is analyzed.

In addition, the extrapolation melting start temperature means the starting point of the melting peak temperature, and the melting that maximizes the difference in the input of heat energy from the straight line that extends the low temperature (65 to 75°C) side baseline to the high temperature side. The temperature at the intersection with the tangent line drawn at the point where the slope is maximum is the temperature on the cold side of the peak. The extrapolation melting end temperature means the end point of the melting peak temperature, and the high temperature side of the melting peak at which the difference in the input of heat energy is the maximum from the straight line extending the high temperature (170°C) side baseline to the low temperature side. The temperature at the intersection of the curve and the tangent line drawn at the point where the gradient becomes maximum.

In the battery packaging material of the present invention, the heat-fusible resin layer is heat-fused with the electrolyte in contact with the heat-fusible resin layer in a high temperature environment, and the electrolyte is attached to the heat-fusible resin layer. In this case, the value (ratio T ₂ /T ₁ ) obtained by dividing the temperature difference T ₂ by the temperature difference T ₁ may be, for example, from the viewpoint of exhibiting a higher seal strength by heat fusion. 0.55 or more, preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.75 or more, and a preferable range is about 0.55 to 1.0, 0.60 to 1 .0, about 0.70 to 1.0, about 0.75 to 1.0. The upper limit is 1.0, for example. In order to set such a ratio T ₂ /T ₁ , for example, the type, composition, molecular weight, etc. of the resin constituting the heat-fusible resin layer 4 are adjusted.

[Adhesive layer 5]
In the battery packaging material of the present invention, the adhesive layer 5 is a layer provided between the barrier layer 3 and the heat-fusible resin layer 4 as needed in order to firmly bond them together.

The adhesive layer 5 is formed of a resin that can bond the barrier layer 3 and the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, the same adhesive mechanism, kind of adhesive component, and the like as the adhesive exemplified in the adhesive layer 2 can be used. Further, as the resin used for forming the adhesive layer 5, polyolefin resins such as the polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the above heat-fusible resin layer 4 can also be used. .. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene. That is, the resin forming the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. In addition, when the resin constituting the adhesive layer 5 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Further, from the viewpoint of a battery packaging material having excellent shape stability after molding while reducing the thickness of the battery packaging material, the adhesive layer 5 is a cured resin composition containing an acid-modified polyolefin and a curing agent. It may be a thing. As the acid-modified polyolefin, the same ones 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.

The curing agent is not particularly limited as long as it cures the acid-modified polyolefin. Examples of the curing agent include an epoxy curing agent, a polyfunctional isocyanate curing agent, a carbodiimide curing agent, and an oxazoline curing agent.

The epoxy curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of the epoxy curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The polyfunctional isocyanate 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), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), those obtained by polymerizing or nurate these, Examples thereof include a mixture and a copolymer with another polymer.

The carbodiimide curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N=C=N-). The carbodiimide-based curing agent is preferably a polycarbodiimide compound having at least two carbodiimide groups.

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 Co., Ltd.

From the viewpoint of enhancing the adhesion between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5, 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% by mass, more preferably in the range of about 0.1 to 30% by mass, More preferably, it is in the range of about 0.1 to 10% by mass.

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer, but when the adhesive exemplified in the adhesive layer 2 is used, it is preferably about 1 to 10 μm, more preferably 1 to 10 μm. The thickness is about 5 μm. When the resin exemplified in the heat-fusible resin layer 4 is used, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. Further, 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, 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.

In the battery packaging material of the present invention, the adhesive layer 5 preferably has a logarithmic decrement ΔE at 120° C. in the rigid pendulum measurement of, for example, 2.5 or less, and more preferably 2.0 or less. In the present invention, the logarithmic decrement ΔE at 120° C. is, for example, 2.5 or less, further 2.0 or less, so that when the battery element is sealed with the battery packaging material, the heat-fusible resin layer Crushing of the adhesive layer when heat-sealing each other is effectively suppressed, and high sealing strength is exhibited in a high temperature environment.

The logarithmic decay rate at 120° C. in the rigid pendulum measurement is an index showing the hardness of the resin in a high temperature environment of 120° C., and the smaller the logarithmic decay rate, the higher the resin hardness. In the rigid pendulum measurement, the damping rate of the pendulum when the temperature of the resin is raised from a low temperature to a high temperature is measured. In the rigid pendulum measurement, generally, the edge portion is brought into contact with the surface of the measurement target object, and the pendulum movement is performed in the left-right direction to impart vibration to the measurement target object. In the battery packaging material of the present invention, a hard adhesive layer 5 having a logarithmic decrement in a high temperature environment of 120° C. of, for example, 2.5 or less, and further 2.0 or less is formed on the barrier layer 3 and the heat-fusible resin layer 4. By arranging between them, it is possible to prevent the adhesive layer 5 from being crushed (thinned) at the time of heat-sealing the battery packaging material, and further to exhibit high sealing strength in a high temperature environment.

The logarithmic decrement ΔE is calculated by the following formula.
ΔE=[ln(A1/A2)+ln(A2/A3)+...ln(An/An+1)]/n
A: amplitude n: wave number

In the battery packaging material of the present invention, from the viewpoint of effectively suppressing crushing of the adhesive layer 5 when heat-sealing the heat-fusible resin layers 4 to each other, and further exhibiting high seal strength in a high temperature environment. The logarithmic attenuation rate ΔE at 120° C. is, for example, about 1.4 to 2.5, preferably about 1.4 to 2.0, and more preferably about 1.4 to 1.6. In order to set the logarithmic attenuation rate ΔE, for example, the type, composition, molecular weight, etc. of the resin forming the adhesive layer 5 are adjusted.

In the measurement of the logarithmic decrement ΔE, a commercially available rigid pendulum type physical property tester was used, and a cylindrical cylinder edge was used as an edge portion to be pressed against the adhesive layer 5, the initial amplitude was 0.3 degree, and the temperature was from 30°C to 200°C. A rigid pendulum physical property test is performed on the adhesive layer 5 at a temperature rising rate of 3° C./min in the range. Then, based on the logarithmic decrement at 120° C., the standard for suppressing the collapse of the adhesive layer 5 and improving the seal strength by heat fusion in a high temperature environment was set. Regarding the adhesive layer for measuring the logarithmic decrement ΔE, the battery packaging material was immersed in 15% hydrochloric acid to dissolve the base material layer and the aluminum foil, and only the adhesive layer and the heat-fusible resin layer were formed. Allow the sample to dry sufficiently before measurement.

It is also possible to obtain the battery packaging material from the battery and measure the logarithmic decrement ΔE of the adhesive layer 5. When the battery packaging material is obtained from the battery and the logarithmic decrement ΔE of the adhesive layer 5 is measured, a sample is cut out from the top surface portion that is less affected by stretching of the battery packaging material as a measurement target.

Further, in the battery packaging material of the present invention, the heat-fusible resin layers of the laminate constituting the battery packaging material are opposed to each other under the conditions of a temperature of 190° C., a surface pressure of 0.5 MPa, and a time of 3 seconds. After heating and pressing in the laminating direction, the residual ratio of the thickness of the adhesive layer is preferably 70% or more, more preferably 80% or more, and the preferable range is 70 to 95%, 80 to 95%. Are listed. The upper limit of the remaining ratio of the thickness is, for example, about 95%. The remaining ratio of the thickness is a value measured by the following method. In order to set the remaining ratio of the thickness, for example, the type, composition, molecular weight, etc. of the resin forming the adhesive layer 5 are adjusted.

<Measurement of residual ratio of thickness of adhesive layer>
A packaging material for a battery is cut into a length of 150 mm and a width of 60 mm to prepare a test sample. Next, the heat-fusible resin layers of the test sample are made to face each other. Then, in that state, using a metal plate with a width of 7 mm, heat and pressure were applied from both sides of the test sample in the laminating direction under conditions of a temperature of 190° C., a surface pressure of 0.5 MPa, and a time of 3 seconds to perform heat fusion. The heat-resistant resin layers are fused to each other. Next, the heat-sealed portion of the test sample is cut in the stacking direction using a microtome, and the thickness of the adhesive layer is measured on the exposed cross section. Similarly, the test sample before heat fusion is cut in the laminating direction using a microtome, and the thickness of the adhesive layer is measured on the exposed cross section. The ratio of the thickness of the adhesive layer after thermal fusion to the thickness of the adhesive layer before thermal fusion is calculated, and the residual ratio (%) of the thickness of the adhesive layer is measured.

It is also possible to obtain the battery packaging material from the battery and measure the remaining ratio of the thickness of the adhesive layer 5. When the battery packaging material is obtained from the battery and the remaining ratio of the thickness of the adhesive layer 5 is measured, the sample is cut out from the top surface portion that is less affected by the stretching of the battery packaging material as a measurement target.

The logarithmic decrement ΔE of the adhesive layer 5 can be adjusted by, for example, the melt mass flow rate (MFR) of the resin forming the adhesive layer 5, the molecular weight, the melting point, the softening point, the molecular weight distribution, and the crystallinity.

[Surface coating layer 6]
In the battery packaging material of the present invention, if necessary, the outside of the base material layer 1 (barrier layer of the base material layer 1) is used for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, and the like. A surface coating layer 6 may be provided on the side opposite to 3) as necessary.

The surface coating layer 6 can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Of these, the surface coating layer 6 is preferably formed of a two-component curable resin. Examples of the two-component curing type resin forming the surface coating layer 6 include a two-component curing type urethane resin, a two-component curing type polyester resin, a two-component curing type epoxy resin and the like. Moreover, you may mix|blend an additive with the surface coating layer 6.

Examples of the additive include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the additive is not particularly limited, but examples thereof include metals, metal oxides, inorganic substances, and organic substances. Also, the shape of the additive is not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape. Specific examples of the additive include talc, silica, graphite, kaolin, montmorillonite, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high Examples include melting point nylon, acrylate resin, crosslinked acryl, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additives may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment on the surface. Further, on at least one of the surface and the inside of the surface coating layer 6, a lubricant, an anti-blocking agent, a matting agent, if necessary, depending on the surface coating layer 6 and the functionality to be provided on the surface. It may contain additives such as a flame retardant, an antioxidant, a light stabilizer, a tackifier, an antistatic agent and an elastomer resin. Specific examples of the lubricant include the above-mentioned lubricants. Further, the above-mentioned fine particles may function as a lubricant, an anti-blocking agent, and a matting agent.

The method of forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying the two-component curable resin forming the surface coating layer 6 to the outer surface of the base material layer 1. When the additive is blended, the additive may be added to the two-component curable resin, mixed and then applied.

The content of the additive in the surface coating layer 6 is not particularly limited, but is preferably about 0.05 to 1.0 mass%, more preferably about 0.1 to 0.5 mass%.

The thickness of the surface coating layer 6 is not particularly limited as long as the above-mentioned functions of the surface coating layer 6 are exhibited, but is, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. Method for producing battery packaging material For the method for producing a battery packaging material of the present invention, as long as a laminate obtained by laminating each layer of a predetermined composition is obtained, is not particularly limited, at least a substrate layer, a barrier layer, And a step of laminating the heat-fusible resin layer in this order, at least, on the surface of the substrate layer side of the laminate, a fatty acid amide compound is present, as a fatty acid amide compound, A method in which 1 g or more is dissolved in 100 g of methyl ethyl ketone in a 25° C. environment is used. As a method for allowing the lubricant to be present on the surface of the base material layer 1 side, the lubricant may be applied to the surface of the base material layer 1 side or a layer on the base material layer 1 side (for example, the base material layer 1 or the surface coating layer). A lubricant may be included in the resin constituting 6) to cause the lubricant to bleed out on the surface of the base material layer 1 side.

An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminated body in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in order (hereinafter, also referred to as “laminated body A”) is formed. Specifically, the laminate A is formed by applying an adhesive agent used for forming the adhesive agent layer 2 on the base material layer 1 or the barrier layer 3 whose surface has been subjected to chemical conversion treatment, to the gravure coating method, This can be performed by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a roll coating method.

Next, the heat-fusible resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-fusible resin layer 4 is directly laminated on the barrier layer 3, the resin component forming the heat-fusible resin layer 4 is gravure-coated or roll-coated on the barrier layer 3 of the laminate A. It may be applied by such a method. 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 are provided on the barrier layer 3 of the laminate A. Method of laminating by co-extruding 4 (co-extrusion laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated is formed, and this is a barrier layer of the laminated body A. 3 by a thermal lamination method, (3) a method of extruding or solution coating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate A, drying at high temperature, and further baking. A method of laminating the heat-fusible resin layer 4 formed in a sheet shape on the adhesive layer 5 in advance by a thermal lamination method, and (4) the barrier layer 3 of the laminate A and a sheet shape in advance. A method of laminating the laminated body A and the heat-fusible resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the film and the heat-fusible resin layer 4 (sandwich laminating method) And so on.

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed by, for example, applying the above-mentioned resin forming the surface coating layer 6 to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer 6 on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

As described above, the surface coating layer 6/if necessary, the base material layer 1/the adhesive layer 2/if necessary, the barrier layer 3 whose surface has been subjected to chemical conversion treatment/the necessity. A laminated body composed of the adhesive layer 5/the heat-fusible resin layer 4 provided as described above is formed. To further strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as necessary, further, It may be subjected to heat treatment such as hot roll contact type, hot air type, near or far infrared ray type. The conditions for such heat treatment include, for example, 150 to 250° C. and 1 to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate improves or stabilizes film forming properties, lamination processing, suitability for secondary processing of the final product (pouching, embossing molding), etc., if necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed. For example, by performing corona treatment on at least one surface of the base material layer, it is possible to improve or stabilize film-forming properties, laminating processing, suitability for secondary processing of final products, and the like. Furthermore, for example, by performing corona treatment on the surface of the base material layer 1 opposite to the barrier layer 3, the printability of the ink on the surface of the base material layer 1 can be improved.

4. Application of Battery Packaging Material The battery packaging material of the present invention is used for a package for hermetically containing battery elements such as a positive electrode, a negative electrode and an electrolyte. That is, the battery formed by the battery packaging material of the present invention can accommodate a battery element including at least a positive electrode, a negative electrode, and an electrolyte to form a battery.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte, in the battery packaging material of the present invention, with the metal terminals connected to each of the positive electrode and the negative electrode protruding outward, the battery By covering the periphery of the element so that a flange portion (a region where the heat-fusible resin layers contact each other) can be formed, and heat-sealing the heat-fusible resin layers of the flange portion to seal the battery, A battery using the packaging material is provided. When the battery element is housed in a package formed of the battery packaging material of the present invention, the packaging is performed so that the sealant portion of the battery packaging material of the present invention is on the inner side (the surface in contact with the battery element). Form the body.

In the present invention, a step of accommodating a battery element having at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the battery packaging material of the present invention, and applying ink to the surface of the base material layer side. By the method including the step of printing, it is possible to manufacture a battery in which the surface of the base material layer side is printed. That is, the battery of the present invention can be a battery having a printed portion on its surface. In addition, at least a fatty acid amide compound is present on the surface of the laminate on the side of the base material layer, and a battery having a printed portion with ink on the surface of the base material layer side can be obtained.

The battery packaging material of the present invention may be used in either a primary battery or a secondary battery, but is preferably a secondary battery. The type of the secondary battery to which the battery packaging material of the present invention is applied is not particularly limited, and examples thereof include a lithium-ion battery, a lithium-ion polymer battery, a lead storage battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, and a nickel-cadmium storage battery. Iron storage batteries, nickel/zinc storage batteries, silver oxide/zinc storage batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors and the like can be mentioned. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries are mentioned as suitable targets for application of the battery packaging material of the present invention.

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

(Example 1-26 and Comparative Example 1-25)
<Manufacture of battery packaging materials>
An aluminum alloy foil (thickness: 35 μm) as a barrier layer was laminated on the base material layer having the configuration and thickness shown in Table 1 by a dry laminating method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the aluminum alloy foil. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical conversion treatment. The chemical conversion treatment of the aluminum alloy foil is performed by roll coating so that the amount of chromium applied is 10 mg/m ² (dry mass) of the treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid. It was carried out by applying it to and baking it. Next, in Examples 1 to 7, 9 to 19, 21 to 26 and Comparative Examples 1 to 8, 10 to 20, 22 to 25, a carboxylic acid-modified polypropylene (barrier) was formed on the barrier layer of the obtained laminate. 20 μm (disposed on the layer side) and 15 μm of the heat-fusible resin layer (disposed on the innermost layer side) made of the resin shown in Table 1 to form an adhesive layer and a heat-fusible resin on the barrier layer. The layers were laminated to obtain a battery packaging material in which a base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in order. On the other hand, in Examples 8 and 20 and Comparative Examples 9 and 21, the two-pack type epoxy adhesive was applied onto the barrier layer of the obtained laminate, and the adhesive layer (thickness 3 μm) was applied onto the aluminum alloy foil. Is formed, and then the adhesive layer on the barrier layer and an unstretched polypropylene film of 30 μm are laminated by a dry lamination method, and then aging treatment is performed to obtain a base material layer/adhesive layer/barrier layer/adhesive layer/heat. A packaging material for a battery in which the fusible resin layers were laminated in order was obtained.

Next, a fatty acid amide compound was applied to the surface of the base material layer of each battery packaging material. However, fatty acid amide was not applied to the battery packaging material of Comparative Example 1. The amounts of various fatty acid amide compounds present on the surface of the base material layer are as shown in Table 1, respectively. The amounts (g) of various fatty acid amide compounds dissolved in 100 g of methyl ethyl ketone (MEK) in a 25° C. environment are as shown in Table 1. It was erucic acid amide that had a dissolved amount of 6.30 g based on 100 g of MEK. Further, it was ethylenebisoleic acid amide that had a dissolved amount of 1.11 g with respect to 100 g of MEK. It was oleic acid amide that had a dissolved amount of 11.64 g with respect to 100 g of MEK. It was stearic acid amide that dissolved 0.92 g in 100 g of MEK. It was ethylenebisstearic acid amide that had a dissolved amount of 0.07 g with respect to 100 g of MEK. The amount of dissolution (g) of various fatty acid amide compounds in 100 g of methyl ethyl ketone (MEK) in a 25° C. environment was measured by the method described above. A high performance liquid chromatograph "LC-2000Plus" manufactured by JASCO Corporation was used as the high performance liquid chromatograph (HPLC). In addition, in Examples 1-25 and Comparative Examples 1-25, after a predetermined amount of erucic acid amide was contained in the heat-fusible resin layer, bleeding out was performed so that the eruca The acid amide was present at 35.0 mg/m ² . On the other hand, in Example 26, no lubricant was present on the surface of the heat-sealing resin layer.

In addition, in the battery packaging materials of Examples 4 and 16 and Comparative Examples 5 and 17, the surface of the base material layer was subjected to corona treatment before applying the fatty acid amide compound. For the corona treatment, a corona surface treatment device manufactured by Wedge Co., Ltd. was used, and the corona treatment was performed at a constant speed of an output of 1.0 Kw and 10 m/min.

(Measurement of wet tension)
The wetting tension of the surface of the base material layer side of each of the battery packaging materials obtained above was measured by a method in conformity with JIS K6768:1999. Using a mixture for wetting tension test manufactured by Nacalai Tesque, the reagent contained in spherical absorbent cotton was linearly applied to the surface of the base material layer side of each battery packaging material at 6 cm ^2. After 2 seconds, it was visually determined whether or not the liquid film was broken, and the wetting tension when the liquid film was not broken was defined as the surface wetting tension. The wet tension was measured in an environment of a temperature of 23° C. and a relative humidity of 50%. The results are shown in Table 1.

(Evaluation of moldability)
Each of the battery packaging materials obtained above was cut into a rectangle of 80 mm×120 mm to prepare a sample. These samples were molded in a mold having a diameter of 30 mm×50 mm in an environment of a temperature of 24° C. and a relative humidity of 50% (female mold, the surface is JIS B 0659-1:2002 Annex 1 (reference) Comparative surface roughness. The maximum height roughness (nominal value of Rz) specified in Table 2 of the standard piece is 3.2 μm, and a molding die corresponding to this (male, surface is JIS B 0659-1: 2002 Annex 1 (reference) Using the maximum height roughness (Rz nominal value is 1.6 μm) specified in Table 2 of the surface roughness standard piece for comparison, the pressing pressure is 0.4 MPa and 0 Molding is performed by increasing the molding depth in increments of 0.5 mm from the molding depth of 0.5 mm, and a molding depth of 0.5 mm shallower than the molding depth when pinholes are generated in the battery packaging material. The maximum forming depth of From this limit molding depth, the moldability of the battery packaging material was evaluated according to the following criteria. The results are shown in Table 1.
A: Limiting forming depth of 6.0 mm or more B: Limiting forming depth of 5.0 mm or more and 5.5 mm or less C: Limiting forming depth of 4.0 mm or more and 4.5 mm or less D: Limiting forming depth of 3.5 mm or less

(Evaluation of continuous productivity of batteries)
Each of the battery packaging materials obtained above was cut into a rectangle of 80 mm×120 mm to prepare a sample. Next, in an environment of a temperature of 24° C. and a relative humidity of 50%, these samples were subjected to a molding die having a diameter of 30 mm×50 mm (female die, surface is JIS B 0659-1:2002 Annex 1 (reference)) The maximum height roughness (Rz nominal value) specified in Table 2 of the surface roughness standard piece for use is 3.2 μm, and the corresponding molding die (male, surface is JIS B 0659). −1:2002 Annex 1 (reference) Using the maximum height roughness (nominal value of Rz) of 1.6 μm defined in Table 2 of the surface roughness standard piece for comparison, the pressing pressure is set to 0. 1000 pieces of cold forming were performed at a forming depth of 4 mm and 5 mm, respectively. Next, the corner portion of the mold after cold forming was visually observed, and the continuous formability of the battery packaging material was evaluated based on the following criteria. The results are shown in Table 1.
A: The fatty acid amide compound is not transferred to the male mold and the female mold, and the mold is not whitened, so that the moldability is high. B: The fatty acid amide compound is only one of the male mold and the female mold. C: Fatty acid amide compound has been transferred to both male and female molds, and the mold has been whitened. Is low

(Evaluation of printability)
As an ink jet printing machine, 9040 manufactured by Markem Image Co., Ltd. was used, and as ink, MB175 manufactured by Markem Image Co., Ltd. was used. Printing was performed on the surface of the base material layer side of the battery packaging material obtained above using the inkjet printing machine and ink, and then dried for 10 seconds in an environment of a temperature of 24° C. and a relative humidity of 50%. Next, a tape (S600 manufactured by 3M Co.) was attached on the printed pattern, and the printed pattern and the tape were brought into close contact with each other by reciprocating once with a 2 kg roller from the tape. Next, by peeling the tape in a direction perpendicular to the surface of the base material layer and observing the exposed print pattern with an optical microscope, the entire print pattern area (100% of the area of the peeled portion) of the print pattern was removed. ) Was measured, and the following numerical values were used to give a rating. The printability was evaluated in an environment of a temperature of 24° C. and a relative humidity of 50%. The results are shown in Table 1.

10: No peeling of print pattern 9: Peeling of print pattern is more than 0% and 10% or less of the whole print pattern 8: Peeling of print pattern is more than 10% and 20% or less of the whole print pattern 7: Peeling of print pattern Is more than 20% and less than 30% of the whole printed pattern 6: Peeling of the printed pattern is more than 30% and less than 40% of the whole printed pattern 5: Peeling of the printed pattern is more than 40% and more than 50% of the entire printed pattern The following 4: Peeling of the printed pattern is more than 50% and 60% or less of the entire printed pattern 3: The peeled-off of the printed pattern is more than 60% and 70% or less of the entire printed pattern 2: The peeling of the printed pattern is the entire printed pattern 70% or more and 80% or less 1: Peeling of print pattern is more than 80% and 90% or less of the whole print pattern 0: Peeling of print pattern is more than 90% and 100% or less of the whole print pattern

*In Example 26, no lubricant was present on the surface of the heat-sealing resin layer.

In Table 1, ONy is biaxially stretched nylon, PET is polyethylene terephthalate, PBT is polybutylene terephthalate, and PET/ONy is that PET is located on the opposite side of the barrier layer from polyethylene terephthalate (12 μm) and nylon. It is a laminated film obtained by dry lamination with (15 μm). PET•ONy has a base material layer formed of a laminated film obtained by coextrusion of polyethylene terephthalate (3 μm) and nylon (12 μm). Further, PP means polypropylene, PE means polyethylene, and CPP means unstretched polypropylene.

From the results shown in Table 1, a fatty acid amide compound is present on the surface of the base material layer side of the battery packaging material, and the fatty acid amide compound is 1 g or more per 100 g of methyl ethyl ketone in a 25° C. environment. It is understood that the battery packaging materials of Examples 1 to 26, which are soluble, have both excellent printability and excellent moldability, and are also excellent in battery continuous productivity.

<Measurement of logarithmic attenuation rate ΔE of adhesive layer>
Each of the battery packaging materials obtained in Example 1 and Example 3 was cut into a rectangle having a width (TD: Transverse Direction) of 15 mm and a length (MD: Machine Direction) of 150 mm, and a test sample (the battery packaging material 10). ). The MD of the battery packaging material corresponds to the rolling direction (RD) of the aluminum alloy foil, the TD of the battery packaging material corresponds to the TD of the aluminum alloy foil, and the rolling direction of the aluminum alloy foil (RD ) Can be discriminated by rolling eyes. When the MD of the battery packaging material cannot be specified due to the rolled grain of the aluminum alloy foil, it can be specified by the following method. As a method for confirming the MD of the packaging material for a battery, the cross section of the heat-fusible resin layer of the packaging material for a battery is observed with an electron microscope to check the sea-island structure, and the direction perpendicular to the thickness direction of the heat-fusible resin layer is confirmed. The direction parallel to the cross section in which the average diameter of the island shape is maximum can be determined as MD. Specifically, the angle in the longitudinal direction of the heat-fusible resin layer is changed by 10 degrees from the direction parallel to the longitudinal cross section, and each angle up to the direction perpendicular to the longitudinal cross section is changed. The sea-island structure is confirmed by observing each of the sections (total of 10 sections) with an electron micrograph. Next, the shape of each individual island is observed in each cross section. Regarding the shape of each island, a straight line distance connecting the leftmost end in the direction perpendicular to the thickness direction of the heat-fusible resin layer and the rightmost end in the vertical direction is defined as a diameter y. In each cross section, the average of the top 20 diameters y in the descending order of the diameter y of the island shape is calculated. The direction parallel to the cross section in which the average of the diameter y of the island shape is the largest is determined as MD. FIG. 8 shows a schematic diagram for explaining a method of measuring the logarithmic decrement ΔE by measuring the rigid pendulum. Using a rigid pendulum type physical property tester (model number: RPT-3000W, manufactured by A&D Co., Ltd.), the frame of the pendulum 30 is FRB-100, the cylindrical cylinder edge 30a of the edge part is RBP-060, cold heat CHB-100, a vibration displacement detector 32, and a weight 33 were used for the block 31, and the initial amplitude was set to 0.3 degree. The measurement surface (bonding layer) of the test sample is placed on the cooling/heating block 31 so that the axial direction of the cylindrical cylinder edge 30a with the pendulum 30 is orthogonal to the MD direction of the test sample on the measurement surface. installed. In addition, in order to prevent the test sample from floating and warping during measurement, a tape was attached to a location on the cooling/heating block 31 where the measurement result of the test sample was not affected. The cylindrical cylinder edge was brought into contact with the surface of the adhesive layer. Next, using the cooling/heating block 31, the logarithmic decay rate ΔE of the adhesive layer was measured in the temperature range of 30° C. to 200° C. at a temperature rising rate of 3° C./min. The logarithmic decay rate ΔE when the surface temperature of the adhesive layer of the test sample (battery packaging material 10) was 120° C. was adopted. (The test sample once measured was not used, and the average value measured three times (N=3) using a newly cut one was used.) For the adhesive layer, the packaging material for each battery obtained above Was immersed in 15% hydrochloric acid to dissolve the base material layer and the aluminum foil, and the test sample including only the adhesive layer and the heat-fusible resin layer was sufficiently dried to measure the logarithmic decrement ΔE. Table 2 shows the logarithmic decay rate ΔE at 120° C., respectively. (Note that the logarithmic decay rate ΔE is calculated by the following equation.
ΔE=[ln(A1/A2)+ln(A2/A3)+. ． ． +ln(An/An+1)]/n
A: amplitude n: frequency)

<Measurement of residual ratio of thickness of adhesive layer>
Each of the battery packaging materials obtained in Example 1 and Example 3 was cut into a length of 150 mm and a width of 60 mm to prepare a test sample (battery packaging material 10). Next, the heat-fusible resin layers of the test samples of the same size made from the same battery packaging material were opposed to each other. Then, in that state, using a metal plate having a width of 7 mm, the test sample was heated from both sides in the stacking direction at a temperature of 190° C., a surface pressure (0.5 MPa) described in Table 2, and a time of 3 seconds. The pressure was applied to heat-bond the heat-fusible resin layers to each other. Next, the heat-sealed portion of the test sample was cut in the stacking direction using a microtome, and the thickness of the adhesive layer was measured on the exposed cross section. Similarly, the test sample before heat fusion was cut in the laminating direction using a microtome, and the thickness of the adhesive layer was measured on the exposed cross section. The ratio of the thickness of the adhesive layer after heat fusion to the thickness of the adhesive layer before heat fusion was calculated, and the remaining ratio (%) of the thickness of the adhesive layer was measured. The results are shown in Table 2.

<Measurement of seal strength in 25°C environment or 140°C environment>
Each of the battery packaging materials obtained in Example 1 and Example 3 was cut into a rectangle having a width of 60 mm and a length of 150 mm to obtain a test sample (battery packaging material 10). Next, as shown in FIG. 5, the test sample was folded back at the center P in the lengthwise direction, and the heat-fusible resin layers were opposed to each other. Next, using a metal plate 20 having a width of 7 mm, the surface pressure was 1.0 MPa, the time was 1 second, and the temperature was 190° C., the length of the test sample was 7 mm (width of the metal plate), and the entire width direction (that is, 60 mm). In, the heat-fusible resin layers were heat-fused. Next, using a double-edged sample cutter, the test sample was cut into a width of 15 mm as shown in FIG. In FIG. 6, the heat-sealed region is indicated by S. Next, as shown in FIG. 7, in a T-shaped peeling test, using a tensile tester, at a temperature of 25° C. or a temperature of 140° C., a pulling speed of 300 mm/min, a peeling angle of 180°, Under the condition that the distance between chucks is 50 mm, the heat-bonded interface is peeled off, and the maximum value of peeling strength (N/15 mm) for 1.5 seconds from the start of tensile strength measurement is the seal strength in an environment of 25°C. And the seal strength in a 140° C. environment. The tensile test at each temperature was performed in a constant temperature bath, and the test sample was attached to the chuck in the constant temperature bath at a predetermined temperature and held for 2 minutes before starting the measurement. Each seal strength is an average value (n=3) measured in the same manner by producing three test samples. The results are shown in Table 2.

From the results shown in Table 2, in the battery packaging materials of Examples 1 and 3, the logarithm at 120° C. in the rigid pendulum measurement of the adhesive layer located between the barrier layer and the heat-fusible resin layer. It can be seen that the damping ratio ΔE is 2.5 or less, the crushing of the adhesive layer when heat-sealing the heat-fusible resin layers is effectively suppressed, and high sealing strength is exhibited in a high temperature environment. .. Further, in the battery packaging material of Example 1, the logarithmic attenuation rate ΔE at 120° C. in the rigid pendulum measurement of the adhesive layer located between the barrier layer and the heat-fusible resin layer was 2.0. It is shown below that crushing of the adhesive layer when heat-sealing the heat-fusible resin layers is effectively suppressed, and particularly high seal strength is exhibited in a high temperature environment. Further, in Examples 2, 5, 6, 9-18, and 21-26, the same maleic anhydride-modified polypropylene as in Example 1 was used for the adhesive layer, and these examples are similar to those of Example 2 in Table 2. It can be said that the result is similar to the result. Further, since Examples 3 and 4 also use the same maleic anhydride-modified polypropylene, it can be said that these Examples have similar results.

<Measurement of extrapolation melting start temperature and extrapolation melting end temperature of melting peak temperature>
For the polypropylene used for the heat-fusible resin layer of each of the battery packaging materials obtained in Examples 1 and 3 by the following method, the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature were measured. The temperature difference T ₁ , T ₂ between the extrapolation melting start temperature and the extrapolation melting end temperature is measured, and the ratio (T ₂ /T ₁₎ is calculated from the values of the obtained temperature differences T ₁ , T _2. ) And the absolute value of the difference |T ₂ −T ₁ |. The results are shown in Table 3.

(Measurement of temperature difference T ₁ )
According to JIS K7121:2012, a differential scanning calorimetry (DSC) was used to obtain a DSC curve for the polypropylene used for the heat-fusible resin layer of the above-mentioned battery packaging material. From the obtained DSC curve, the temperature difference T ₁ between the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature of the heat-fusible resin layer was measured.

(Measurement of temperature difference T ₂ )
In an environment of a temperature of 85° C., polypropylene used for the heat-fusible resin layer was prepared by using lithium hexafluorophosphate at a concentration of 1 mol/l and a volume ratio of ethylene carbonate, diethyl carbonate and dimethyl carbonate of 1:1: It was allowed to stand for 72 hours in the electrolytic solution as the solution of No. 1 and then sufficiently dried. Next, in accordance with JIS K7121:2012, a differential scanning calorimetry (DSC) was used to obtain a DSC curve for the dried polypropylene. Next, from the obtained DSC curve, the temperature difference T ₂ between the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature of the dried heat-fusible resin layer was measured.

In measuring the extrapolation melting start temperature and the extrapolation melting end temperature of the melting peak temperature, TA200 Q200 manufactured by TA Instruments was used as a differential scanning calorimeter. As the DSC curve, after holding the test sample at -50°C for 10 minutes, the temperature was raised to 200°C at a temperature rising rate of 10°C/minute (first time), and held at 200°C for 10 minutes, and then the temperature lowering rate. After the temperature was lowered to -50°C in -10°C minutes and kept at -50°C for 10 minutes, the temperature was raised to 200°C at a temperature elevation rate of 10°C/minute (second time), and kept at 200°C for 10 minutes, and then 2 The DSC curve when the temperature was raised to 200° C. for the second time was used. In addition, when measuring the temperature difference T ₁ and the temperature difference T ₂ , in each DSC curve, of the melting peaks appearing in the range of 120 to 160° C., the melting peak with the largest difference in the input of heat energy is analyzed. went. Even when two or more peaks were overlapped with each other, the analysis was performed only for the melting peak in which the difference in input of thermal energy was the maximum.

In addition, the extrapolation melting start temperature means the starting point of the melting peak temperature, and the melting that maximizes the difference in the input of heat energy from the straight line that extends the low temperature (65 to 75°C) side baseline to the high temperature side. The temperature at the intersection of the curve on the low temperature side of the peak and the tangent line drawn at the point where the gradient becomes maximum was taken. The extrapolation melting end temperature means the end point of the melting peak temperature, and the high temperature side of the melting peak at which the difference in the input of heat energy is the maximum from the straight line extending the high temperature (170°C) side baseline to the low temperature side. The temperature at the intersection of the curve and the tangent line drawn at the point where the gradient becomes maximum was taken.

<Measurement of seal strength before contact with electrolyte>
In <Measurement of seal strength after contact with electrolytic solution> described below, tensile strength (seal strength) was measured in the same manner except that the electrolytic solution was not injected into the test sample. The maximum tensile strength until the heat-sealed portion is completely peeled off is defined as the sealing strength before contact with the electrolytic solution. In Table 3, the sealing strength before contact with the electrolytic solution is described as the sealing strength when the contact time of the electrolytic solution at 85° C. is 0 h.

<Measurement of seal strength after contact with electrolyte>
As shown in the schematic view of FIG. 9, each of the battery packaging materials obtained in Example 1 and Example 3 was cut into a rectangle having a width (x direction) of 100 mm and a length (z direction) of 200 mm to obtain a test sample. (Battery packaging material 10) (Fig. 9a). The test sample (battery packaging material 10) was folded back at the center in the z direction so that the heat-fusible resin layer sides were overlapped (Fig. 9b). Next, both ends in the x direction of the folded back test sample were sealed by heat sealing (temperature 190° C., surface pressure 2.0 MPa, time 3 seconds), and formed into a bag shape having one opening E (FIG. 9c). Next, an electrolyte solution (concentration of lithium hexafluorophosphate is 1 mol/l and volume ratio of ethylene carbonate, diethyl carbonate and dimethyl carbonate is 1:1: 1) from the opening E of the bag-shaped test sample. 6 g of the solution 1) was injected (FIG. 9d), and the end of the opening E was sealed by heat sealing (temperature 190° C., surface pressure 2.0 MPa, time 3 seconds) (FIG. 9e). Next, the folded back portion of the bag-shaped test sample was turned downward, and the bag was allowed to stand in an environment of a temperature of 85° C. for a predetermined storage time (a time for contacting with an electrolytic solution, 24 hours, 72 hours). The end of the test sample was then cut (Fig. 9e) and all the electrolyte was drained. Next, with the electrolytic solution attached to the surface of the heat-fusible resin layer, the upper and lower surfaces of the test sample were sandwiched between metal plates 20 (7 mm width), and the temperature was 190° C., the surface pressure was 1.0 MPa, and the time was 3 seconds. The heat-fusible resin layers were heat-fused under the conditions (FIG. 9f). Next, the test sample was cut into a width of 15 mm with a double-edged sample cutter so that the seal strength at a width (x direction) of 15 mm could be measured (FIGS. 9f and 9g). Next, using a tensile tester (manufactured by Shimadzu Corporation, AGS-xplus (trade name)) so as to achieve T-shaped peeling, at a temperature of 25° C., a pulling speed of 300 mm/min, a peeling angle of 180°, and a chuck. The tensile strength (seal strength) was measured by peeling the heat-sealed interface under the condition that the distance was 50 mm (FIG. 7). The maximum tensile strength until the heat-sealed portion was completely peeled (the distance until peeling was 7 mm, which is the width of the metal plate) was taken as the sealing strength after contact with the electrolytic solution.

Table 4 shows the retention rate (%) of the seal strength after contacting with the electrolytic solution, based on the seal strength before contacting with the electrolytic solution (100%).

From the results shown in Table 4, in the battery packaging materials of Examples 1 and 3, the value obtained by dividing the temperature difference T ₂ by the temperature difference T ₁ is 0.55 or more, which indicates that the heat melting in the high temperature environment occurs. When the electrolytic solution is in contact with the adhesive resin layer, and the thermal adhesive resin layers are thermally fused together in a state where the electrolytic solution is attached to the thermal adhesive resin layer, high sealing strength is obtained by thermal fusion. I know that it will work. In the battery packaging material of Example 1, the value obtained by dividing the temperature difference T ₂ by the temperature difference T ₁ is 0.60 or more, and the electrolytic solution is applied to the heat fusible resin layer in a high temperature environment. It can be seen that even when the heat-fusible resin layers are heat-sealed to each other in the state where the heat-fusible resin layers are in contact with each other and the electrolytic solution is attached to the heat-fusible resin layer, the heat-sealing exhibits particularly high sealing strength. The heat-fusible resin layer of each Example is measured by the method described below by adjusting the amount of the low molecular weight component in polypropylene, the starting point of the melting peak temperature of the heat-fusible resin layer ( The value (T ₂ /T ₁ ) obtained by dividing the temperature difference T ₂ between the extrapolation melting start temperature) and the end point (extrapolation melting end temperature) by the temperature difference T ₁ is adjusted. In addition, in Examples 2, 5, 6, 9-18, and 21-26, the same polypropylene as that in Example 1 was used for the heat-fusible resin layer, and these Examples are those shown in Tables 3 and 4. It can be said that the result is similar to the result of Example 1. Further, since the same polypropylene is used for the heat-fusible resin layer in Examples 3 and 4, it can be said that these Examples have similar results.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 6 Surface coating layer 10 Packaging material for batteries

Claims (14)

At least, a substrate layer, a barrier layer, and a heat-fusible resin layer is formed of a laminate provided in this order,
At least, on the surface of the layered product on the side of the base material layer, a fatty acid amide compound is present,
A packaging material for a battery, wherein 1 g or more of the fatty acid amide compound dissolves in 100 g of methyl ethyl ketone in a 25° C. environment. The battery packaging material according to claim 1, wherein the fatty acid amide compound is present in an amount of 2.0 mg/m ² or more on the surface of the layered product on the side of the base material layer. The packaging material for a battery according to claim 1 or 2, which is used for printing an ink on the surface of the laminate on the side of the base material layer. The battery packaging material according to claim 3, wherein the ink contains at least one selected from the group consisting of methyl ethyl ketone, acetone, isopropyl alcohol, and ethanol. The packaging material for a battery according to claim 1, wherein the surface of the base material layer has a wetting tension of 32 mN/m or more. The fatty acid amide compound is at least one selected from the group consisting of erucic acid amide, ethylenebisoleic acid amide, oleylstearic acid amide, stearyl oleic acid amide, stearyl erucic acid amide, oleic acid amide, and behenic acid amide. The packaging material for batteries according to any one of claims 1 to 5. The packaging material for batteries according to claim 1, wherein a fatty acid amide compound is present on the surface of the heat-fusible resin layer side. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package made of the battery packaging material according to any one of claims 1 to 7. The battery according to claim 8, which has a printed portion on a surface of the packaging body on the side of the base material layer. The battery according to claim 8 or 9, which has a printed portion made of ink on a surface of the packaging body on the side of the base material layer. At least, including a step of laminating the base material layer, the barrier layer, and the heat-fusible resin layer in this order,
At least a fatty acid amide compound is present on the surface of the base material layer side of the laminate,
The method for producing a packaging material for a battery, wherein the fatty acid amide compound is one that dissolves 1 g or more in 100 g of methyl ethyl ketone in an environment of 25°C. The method for producing a battery packaging material according to claim 11, further comprising a step of subjecting at least one surface of the base material layer to corona treatment. A step of accommodating a battery element having at least a positive electrode, a negative electrode, and an electrolyte in a package made of the battery packaging material according to any one of claims 1 to 7;
A step of performing printing with ink on the surface of the base material layer side of the package,
A method for manufacturing a battery, comprising: At least 1 g is dissolved in 100 g of methyl ethyl ketone in a 25° C. environment on the surface of the packaging material for a battery, which is composed of a laminate having a base material layer, a barrier layer, and a heat-fusible resin layer in this order. The method for improving the printability of the ink for the surface of the base material layer side surface of the battery packaging material by allowing the fatty acid amide compound to exist.

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