JP2020092094A - Battery packaging material, manufacturing method of the same, and battery - Google Patents

Abstract

To provide a battery packaging material having excellent moldability and excellent durability in a moist heat environment after molding.SOLUTION: The battery packaging material is composed of a laminate including at least: a base material layer; an adhesive layer; a barrier layer; and a heat-fusible resin layer in this order. In thermomechanical analysis to measure a displacement of a probe, the probe is installed on an adhesive layer surface of a cross section of the laminate. At a time of starting the measurement, a deflection setting value of the probe is -4 V, and a heating rate is 5°C/min. When the probe is heated from 40°C to 350°C, a temperature at which the displacement of the probe is maximum is 190°C or higher and 320°C or lower.SELECTED DRAWING: None

Description

The present invention relates to a battery packaging material, a method for manufacturing the same, and a battery.

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 frequently used as battery packaging.

On the other hand, in recent years, as electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like have become higher in performance, batteries are required to have various shapes, and to be thin and lightweight. However, the metal battery packaging materials that have been widely used in the past have the drawbacks that it is difficult to follow the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as a battery packaging material that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base material layer/barrier layer/heat-fusible resin layer is sequentially laminated. The body is proposed.

In such a battery packaging material, generally, a recess is formed by cold molding, and a battery element such as an electrode or an electrolytic solution is arranged in the space formed by the recess, and the heat-fusible resin layers are bonded to each other. By heat-sealing, a battery in which a battery element is housed inside a battery packaging material can be obtained. However, such a film-shaped packaging material is thinner than a metallic packaging material and has a drawback that pinholes and cracks are likely to occur during molding. When pinholes or cracks occur in the battery packaging material, the electrolyte may penetrate into the barrier layer and form metal deposits, which may result in short circuits. It is indispensable for a battery packaging material to have a property that pinholes and the like are unlikely to occur during molding, that is, excellent moldability.

In order to improve the moldability of the film-shaped packaging material for a battery, various studies have been conducted focusing on an adhesive layer for adhering a metal layer. For example, in Patent Document 1, in a laminated packaging material including an inner layer made of a resin film, a first adhesive layer, a metal layer, a second adhesive layer, and an outer layer made of a resin film, the first adhesive layer Further, by forming at least one of the second adhesive layer with an adhesive composition containing a resin having an active hydrogen group in a side chain, a polyfunctional isocyanate, and a polyfunctional amine compound, for deeper molding. It is disclosed that a reliable packaging material can be obtained.

As represented by Patent Document 1, in a conventional battery packaging material composed of a film-like laminate, attention is paid to a compounding component of an adhesive layer for adhering a metal layer and another layer, and a technique for improving moldability. Has been examined a lot.

JP 2008-287971 A

As a result of studies by the present inventors, although the second adhesive layer of Patent Document 1 improves the adhesiveness between the outer layer and the metal layer, the effect of improving the moldability may be insufficient. It became clear.

Further, since automobiles and mobile devices are sometimes used in a harsh environment such as a wet heat environment, it is required to improve the durability of batteries used in such an environment. Therefore, the battery packaging material is further required to have durability in a moist heat environment in which peeling does not easily occur between the outer layer and the metal layer when the molded battery packaging material is placed in a moist heat environment. There is a tendency.

Under such circumstances, the main object of the present invention is to provide a battery packaging material having excellent moldability and also excellent durability in a moist heat environment after molding.

The present inventors have earnestly studied to solve the above problems. As a result, at least a base material layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer is composed of a laminate provided in this order, in the thermomechanical analysis to measure the amount of displacement of the probe, The probe is placed on the surface of the adhesive layer in the cross section of the laminate, the deflection of the probe at the start of measurement is set to -4 V, and the temperature rise rate is 5°C/min. To 350° C., the temperature at which the amount of displacement of the probe becomes maximum is 190° C. or higher and 320° C. or lower. The battery packaging material has excellent moldability and durability in a wet heat environment after molding. It was found that it is also excellent in sex. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the inventions of the following modes.
Item 1. At least a base material layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer is composed of a laminate provided in this order,
In the thermomechanical analysis for measuring the displacement amount of the probe, the probe is installed on the surface of the adhesive layer in the cross section of the laminate, the deflection setting value of the probe at the start of the measurement is -4V, and the heating rate is 5 A battery packaging material in which the temperature at which the displacement of the probe is maximum when the probe is heated from 40°C to 350°C under the condition of °C/min is 190°C or more and 320°C or less.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the adhesive layer is a cured product of a resin composition containing isophthalic acid and a derivative thereof and terephthalic acid and a derivative thereof in a mass ratio of 35:65 to 90:10.
Item 3. The adhesive layer is formed of a polyurethane adhesive containing a main component containing a polyol component and a curing agent containing a polyfunctional isocyanate component,
The polyol component contains a polybasic acid component and a polyhydric alcohol component,
Item 3. The battery packaging material according to Item 2, wherein the polybasic acid component contains the isophthalic acid and its derivative and the terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10.
Item 4. Item 4. The battery packaging material according to any one of Items 1 to 3, wherein the adhesive layer contains a colorant. Item 5. Item 5. The battery packaging material according to any one of Items 1 to 4, wherein the barrier layer has a thickness of 10 µm or more and 100 µm or less.
Item 6. Item 6. The battery packaging material according to any one of Items 1 to 5, wherein the barrier layer is made of an aluminum alloy foil.
Item 7. Item 7. The battery packaging material according to any one of Items 1 to 6, wherein the base material layer contains at least one of polyester and polyamide.
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 formed of the battery packaging material according to any one of Items 1 to 7.
Item 9. At least, a substrate layer, an adhesive layer, a barrier layer, and a step of obtaining a laminate by laminating the heat-fusible resin layer in this order,
In the thermomechanical analysis for measuring the displacement amount of the probe, the probe is installed on the surface of the adhesive layer in the cross section of the laminate, the deflection setting value of the probe at the start of the measurement is -4V, and the heating rate is 5 A method for producing a battery packaging material, wherein the temperature at which the displacement amount of the probe is maximum when the probe is heated from 40° C. to 350° C. under the condition of° C./min is 190° C. or more and 320° C. or less.
Item 10. Item 10. The battery packaging material according to Item 9, wherein the adhesive layer is formed by curing a resin composition containing isophthalic acid or a derivative thereof and terephthalic acid or a derivative thereof in a mass ratio of 35:65 to 90:10. Manufacturing method.

According to the present invention, at least a base material layer, an adhesive layer, a barrier layer, a battery packaging material composed of a laminate provided with a heat-fusible resin layer in this order, excellent formability. It is possible to provide a battery packaging material that is excellent in durability in a moist heat environment after molding. Moreover, according to this invention, the manufacturing method of the said packaging material for batteries, and the battery using the said packaging material for batteries can also be provided.

It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention.

The battery packaging material of the present invention is composed of a laminate including at least a base material layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer in this order, and measures the displacement of the probe. In the thermomechanical analysis, the probe is installed on the surface of the adhesive layer in the cross section of the laminate, and the deflection setting value of the probe at the start of measurement is -4 V and the temperature rising rate is 5°C/min. The temperature at which the displacement amount of the probe becomes maximum when the probe is heated from 40° C. to 350° C. is 190° C. or more and 320° C. or less. Since the battery packaging material of the present invention has such a configuration, it has excellent moldability and excellent durability in a wet heat environment after molding. Therefore, the battery packaging material of the present invention can be suitably used particularly as a packaging material used for a vehicle battery or a mobile device battery. Hereinafter, the battery packaging material of the present invention will be described in detail.

In addition, in this specification, the numerical range shown by "-" means "more than" and "less than". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated Structure of Battery Packaging Material As shown in FIGS. 1 to 3, for example, the battery packaging material of the present invention has at least a base material layer 1, an adhesive layer 2, a barrier layer 3, and a heat-fusible resin layer. It is composed of a laminate having 4 in this order. 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.

As shown in FIGS. 2 and 3, in the battery packaging material of the present invention, for the purpose of improving the adhesiveness between the barrier layer 3 and the heat-fusible resin layer 4, The adhesive layer 5 may be provided if necessary. Further, the battery packaging material of the present invention, as shown in FIG. 3, has a barrier of the base material layer 1 as necessary for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, and the like. If necessary, the surface coating layer 6 may be provided on the side opposite to the layer 3 side.

Although the thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited, the battery packaging material is made thin to increase the energy density of the battery, and the moldability and the molded product From the viewpoint of a battery packaging material having excellent resistance to heat and humidity, for example, 180 μm or less, preferably 150 μm or less, more preferably about 60 to 180 μm, still more preferably about 60 to 150 μm.

2. Each layer forming the battery packaging material [base material layer 1]
In the battery packaging material of the present invention, the base material layer 1 is a layer located 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 resin films such as polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenol resin, polycarbonate, and mixtures and copolymers thereof. .. Among these, polyester and polyamide are preferable, and biaxially stretched polyester and biaxially stretched polyamide are more preferable.

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. And the like. Further, the copolymerized polyester containing ethylene terephthalate as a main repeating unit includes, specifically, a copolymer polyester obtained by polymerizing ethylene terephthalate with ethylene isophthalate as a main repeating unit (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 mainly containing butylene terephthalate as a repeating unit is specifically a copolymer polyester that is polymerized with butylene terephthalate as a 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 the advantage that whitening or the like is less likely to occur due to adhesion of the electrolytic solution, and is preferably used as a material for forming the base material layer 1.

Specific examples of the polyamide include nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and aliphatic polyamides such as copolymers of nylon 6 and nylon 66; terephthalic acid and/or isophthalic acid. Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid), etc., including structural units derived from, polyamides such as hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide, polyamide MXD6 (polymer Polyamides containing aromatics such as taxylylene adipamide; alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); further copolymerization of lactam components and isocyanate components such as 4,4′-diphenylmethane-diisocyanate Polyamide, a polyesteramide copolymer or a polyetheresteramide copolymer, which is a copolymer of a polyamide, a copolyamide and a polyester or a polyalkylene ether glycol; and copolymers thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film has excellent 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 single resin film, but may be formed of two or more resin films in order to improve pinhole resistance and insulation. Specifically, a multilayer structure in which a polyester film and a polyamide film are stacked, a multilayer structure in which a plurality of polyamide films are stacked, a multilayer structure in which a plurality of polyester films are stacked, and the like can be given. When the base material layer 1 has a multilayer structure, a laminate of a biaxially oriented polyamide film and a biaxially oriented polyester film, a laminate of a plurality of biaxially oriented polyamide 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 films, a constitution in which a polyester film and a polyester film are laminated, a constitution in which a polyamide film and a polyamide film are laminated, or a constitution in which a polyester film and a polyamide film are laminated It is preferable that the polyethylene terephthalate film and the polyethylene terephthalate film are laminated, the nylon film and the nylon film are laminated, or the polyethylene terephthalate film and the nylon film are laminated. In addition, since the polyester is unlikely to change its color when the electrolytic solution adheres to the surface thereof, it is preferable to laminate the base material layer 1 so that the polyester is located at the outermost layer in the laminated structure. When the base material layer 1 has a multi-layer structure, the thickness of each layer is preferably about 2 to 25 μm.

When the base material layer 1 is formed of a multilayer resin film, two or more resin films may be laminated via a layer having an adhesive component such as an adhesive or an adhesive resin, and the type of adhesive component used. The amount and the like are the same as in the case of the adhesive layer 2 described later. The method for laminating two or more layers of resins is not particularly limited, and a known method can be adopted, and examples thereof include a dry laminating method, a sandwich laminating method, and a coextrusion laminating method, and a dry laminating method is preferable. Be done. When laminating by a dry laminating method, it is preferable to use a urethane adhesive as the adhesive layer. At this time, the thickness of the adhesive layer is, for example, about 2 to 5 μm.

The base material layer 1 preferably includes at least one of a polyester film layer and a polyamide film layer.

The polyester film layer is preferably composed of a biaxially stretched polyester film, particularly a biaxially stretched polyethylene terephthalate film.

The thickness of the polyester film layer is not particularly limited, but from the viewpoint of providing high insulation between the polyester film layer and the barrier layer 3 while making the battery packaging material thin, the lower limit is preferably about 5 μm. As described above, more preferably about 10 μm or more, the upper limit is preferably about 50 μm or less, more preferably about 30 μm or less, and the preferable range is about 5 to 50 μm or about 10 to 30 μm. ..

The polyamide film layer is preferably composed of a biaxially stretched polyamide film, particularly a biaxially stretched nylon film.

The thickness of the polyamide film layer is not particularly limited, but the lower limit is preferably about 5 μm or more, and more preferably about 10 μm or more, from the viewpoint of exhibiting high insulation while reducing the thickness of the battery packaging material. The upper limit is preferably about 50 μm or less, more preferably about 30 μm or less, and the preferable range is about 5 to 50 μm or about 10 to 30 μm.

When the base material layer 1 has a multilayer structure, the order of laminating the polyester film layer and the polyamide film layer is not particularly limited.

In the present invention, a lubricant is preferably attached to the surface of the base material layer 1 from the viewpoint of improving the moldability of the battery packaging material. The lubricant is not particularly limited, but preferably an amide lubricant is used. Specific examples of the amide-based lubricant include the same as those exemplified for the heat-fusible resin layer 4 described later.

If a lubricant on the surface of the base material layer 1 is present, as it is its abundance is not particularly limited, preferably about 3 mg / m ² or more, more preferably 4~15mg / m ² approximately, more preferably 5~14mg /M ² can be mentioned.

The base material layer 1 may contain a lubricant. Further, the lubricant present on the surface of the base material layer 1 may be one in which the lubricant contained in the resin constituting the base material layer 1 is exuded, or one in which the lubricant is applied to the surface of the base material layer 1. May be

The thickness (total) of the base material layer 1 is not particularly limited as long as the function as the base material layer is exerted, but is, for example, about 3 to 50 μm, preferably about 10 to 35 μm.

[Adhesive layer 2]
In the battery packaging material of the present invention, the adhesive layer 2 improves the moldability of the battery packaging material while firmly adhering the base material layer 1 and the barrier layer 3, and after the battery packaging material is molded. Is a layer provided to improve the durability in a wet heat environment.

In the battery packaging material of the present invention, in thermomechanical analysis for measuring the displacement of the probe, the probe is placed on the surface of the adhesive layer 2 of the cross section of the laminate constituting the battery packaging material, and the measurement is started. The probe deflection setting value is -4 V, and the temperature at which the probe displacement amount is maximum when the probe is heated from 40° C. to 350° C. under the conditions of a temperature rising rate of 5° C./min. The softening point of the agent layer 2 is set in the range of 190 to 320°C.

From the viewpoint of forming the adhesive layer 2 having such a softening point, the adhesive layer 2 is a resin composition containing isophthalic acid and its derivative and terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10. It is preferably a cured product of. More specifically, the adhesive layer 2 is formed of a polyurethane adhesive containing a main component containing a polyol component and a curing agent containing a polyfunctional isocyanate component, and the polyol component is a polybasic acid component. And a polyhydric alcohol component, and the polybasic acid component preferably contains isophthalic acid and its derivative and terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10.

From the viewpoint of improving the moldability of the battery packaging material and further improving the durability in a humid heat environment after molding, the mass ratio of isophthalic acid and its derivative to terephthalic acid and its derivative in the aromatic polybasic acid component is , Preferably about 35:65 to 90:10, more preferably about 40:60 to 85:15.

Examples of the isophthalic acid derivative and the terephthalic acid derivative include, for example, carboxylic acid derivatives. Examples of the carboxylic acid derivative include acid halides, acid anhydrides and esters. Examples of the isophthalic acid derivative and the terephthalic acid derivative include those having a substituent on the benzene ring of isophthalic acid and terephthalic acid, respectively. The substituent is not particularly limited, but examples thereof include an alkyl group (eg, methyl group, ethyl group, propyl group, etc.), halogen atom, hydroxyl group, amino group and the like. The isophthalic acid derivative and the terephthalic acid derivative may each be a carboxylic acid derivative and have a substituent on the benzene ring.

The mass ratio of isophthalic acid and its derivative and terephthalic acid and its derivative in the adhesive layer 2 can be measured using a gas chromatograph mass spectrometer. The specific measuring method can be as follows.

<Measurement of mass ratio of isophthalic acid and its derivative and terephthalic acid and its derivative>
First, as a pretreatment, a methylating agent is used to derivatize the adhesive forming the adhesive layer. An example of the derivatization procedure is as follows. Next, using a gas chromatograph mass spectrometer (for example, Gas Chromatograph Mass Spectrometer (GC/MS) QP2010 manufactured by Shimadzu Corporation) under measurement conditions that allow retention times of isophthalic acid, terephthalic acid, and their derivatives to be separated. Perform analysis. Examples of measurement conditions are as follows.
[Procedure for derivatization]
A 25% methanol solution of tetramethylammonium hydroxide (TMAH) is prepared as a methylating agent. Enclose approximately 5 mg of sample and approximately 3 μl of methylating agent in a glass tube. Next, the glass tube is melted with a gas burner and capped. Next, the electric furnace is heated at 200 to 300° C. for about 15 minutes. Derivatization proceeds during heating. Next, the glass tube is opened and the sample is taken out.
[Measurement condition]
Column: UA-5 FRONTIER LAB (stationary phase 5% diphenyl-95% dimethylpolysiloxane, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm)
Oven temperature: held at 50°C for 5 minutes and heated to 320°C at 10°C/min Ionization method: electron impact ionization method (EI method)
Detector: Quadrupole detector Thermal decomposition temperature: 320°C for 1 min
Injection temperature: 320°C
Quantitative method: Either the absolute calibration curve method or the internal standard method can be used.
The structural isomers of benzenedicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid, and the retention time (retention time) under these measurement conditions is phthalic acid, terephthalic acid, and isophthalic acid in this order.

From the same viewpoint, the proportion of the aromatic polybasic acid component in the polybasic acid component is preferably 40 to 100% by mass or more, more preferably 45 to 95% by mass, and further preferably 50 to 90% by mass. Is mentioned.

The polybasic acid component may include isophthalic acid and its derivative and terephthalic acid and its derivative, and further, naphthalene dicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, anhydrous. Tetrahydrophthalic acid, hexahydrophthalic anhydride, maleic anhydride, itaconic anhydride and its ester compounds may be contained alone or in combination of two or more. Examples of the polyhydric alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-butylene glycol, 1,4-cyclohexanedimethanol. , Trimethylolpropane, glycerin, 1,9-nanondiol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol and the like. These can be used alone or in combination of two or more kinds. The polyfunctional isocyanate component is not particularly limited, but preferably pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), these Examples thereof include polymerized and nurate-formed products, mixtures thereof, and copolymerized products with other polymers.

In the adhesive layer 2, as a content ratio of the main agent and the curing agent, it is particularly preferable if the resin composition forming the adhesive layer 2 is appropriately cured and the adhesive layer 2 having the softening point is formed. Although not limited, from the viewpoint of improving the moldability of the battery packaging material and further improving the durability in a moist heat environment after molding, for example, with respect to 100 parts by mass of the main agent, the curing agent is preferably 1 to 50 parts. The amount is about parts by mass, more preferably about 5 to 40 parts by mass. The equivalent ratio [NCO]/([OH]+[COOH]) of the isocyanate group contained in the curing agent to the total of the hydroxyl group and the carboxyl group contained in the polyol component contained in the main agent is preferably The amount is about 1 to 25, more preferably about 10 to 20.

As described above, in the battery packaging material of the present invention, in thermomechanical analysis for measuring the displacement of the probe, the probe is installed on the surface of the adhesive layer 2 in the cross section of the laminate, and the diff of the probe at the start of the measurement is set. When the probe is heated from 40° C. to 350° C. under the condition that the set value of the rection is −4 V and the temperature rising rate is 5° C./min, the temperature at which the displacement amount of the probe becomes maximum is the softening point of the adhesive layer 2. And the softening point is in the range of 190 to 320°C. The adhesive layer 2 of the battery packaging material of the present invention has such a softening point and contains isophthalic acid and its derivative and terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10. By being a cured product of the resin composition containing, the moldability of the battery packaging material is more suitably improved, and further, the durability in a wet heat environment after molding the battery packaging material can be more suitably improved. it can.

The softening point of the adhesive layer 2 is preferably 190 to 320°C, more preferably 195 to 315°C.

In the battery packaging material of the present invention, the specific method for measuring the softening point of the adhesive layer 2 is as follows.

<Measurement of softening point of adhesive layer>
A probe was set on the surface of the adhesive layer of the cross section of each battery packaging material (the probe tip radius was 30 nm or less, the probe deflection setting value was -4 V), and the probe was heated from 40°C to 350°C. (The temperature rising rate is 5° C./min), and the displacement amount of the probe is measured. Specific examples of the details of the measurement conditions are as follows. As an atomic force microscope equipped with a nano-thermal microscope composed of a cantilever with a heating mechanism, an afm plus system manufactured by ANASYS INSTRUMENTS is used, and as a probe, a cantilever ThermoLever AN2-200 manufactured by ANASYS INSTRUMENTS (spring constant 0.1 to 200). 0.5 N/m) is used. An average value obtained by changing the measurement position and measuring N=3 is used. The measurement results are shown in Table 1, with the temperature at which the amount of displacement is maximum taken as the softening point of the adhesive layer. Three kinds of attached samples (polycaprolactam (melting point 55° C.), polyethylene (melting point 116° C.), polyethylene terephthalate (melting point 235° C.)) were used for calibration, applied voltage 0.1 to 10 V, speed 0.2 V/ The setting value of the second and the deflection is -4V. For each of the three calibration samples, the average value obtained by changing the measurement position and measuring N=3 is used.

In addition, the adhesive layer 2 may include a coloring agent. 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. Further, the colorant may be used alone or in combination of two or more.

For example, specific examples of the inorganic pigment preferably include carbon black and titanium oxide. Specific examples of organic pigments include azo pigments, phthalocyanine pigments and condensed polycyclic pigments. Examples of azo pigments include soluble pigments such as Watching Red and Carmine 6C; insoluble azo pigments such as Monoazo Yellow, Disazo Yellow, Pyrazolone Orange, Pyrazolone Red, and Permanent Red. Phthalocyanine pigments include copper phthalocyanine pigment and no pigment. Examples of the metal phthalocyanine pigment include blue pigments and green pigments, and examples of the condensed polycyclic pigments include dioxazine violet and quinacridone violet. Further, as the pigment, a pearl pigment, a fluorescent pigment or the like can be used.

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 examples thereof include about 5 to 60 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.

The adhesive layer 2 may be formed by curing so as to have the predetermined softening point, and a resin containing isophthalic acid and its derivative and terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10. It is preferable to use a cured product of the composition. For example, the temperature for curing the resin composition forming the adhesive layer 2 is preferably about 40 to 100° C., more preferably about 45 to 90° C., and the heating time is preferably 24 to It is about 144 hours, more preferably about 48 to 120 hours.

[Colored layer]
The colored layer is a layer provided between the base material layer 1 and the adhesive layer 2 or between the adhesive layer 2 and the barrier layer 3 as necessary (not shown). By providing the colored layer, the battery packaging material can be colored.

The coloring layer can be formed, for example, by applying an ink containing a coloring agent to the surface of the adhesive layer 2, the surface of the base material layer 1, or the surface of the barrier layer 3. Known colorants such as pigments and dyes can be used. Further, the colorant may be used alone or in combination of two or more.

Specific examples of the coloring agent contained in the coloring layer are the same as those exemplified in the section of [Adhesive layer 2].

The thickness of the adhesive layer 2 is preferably about 1 to 10 μm, more preferably about 2 to 5 μm.

[Barrier layer 3]
In the battery packaging material, the barrier layer 3 is a layer that not only improves the strength of the battery packaging material but also functions as a barrier layer for preventing water vapor, oxygen, light, and the like from entering the inside of the battery. The barrier layer 3 can be formed of 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 layers, or the like, and is a layer formed of metal. Preferably. Specific examples of the metal forming the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and the like, and preferably aluminum alloys. The barrier layer 3 can be formed by a metal foil or metal vapor deposition, and is preferably formed by a metal foil, more preferably an aluminum alloy foil or a stainless steel 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, for example, annealed aluminum alloy foils (JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H) are used. -O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O) and the like, and it is more preferable to form a soft aluminum alloy foil.

Examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. The stainless steel foil is preferably made of austenitic stainless steel.

Specific examples of the austenitic stainless steel forming the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferable.

The thickness of the barrier layer 3 is not particularly limited as long as it exerts a function as a barrier layer against water vapor and the like, but the upper limit is preferably about 100 μm or less, more preferably about 85 μm or less, further preferably 50 μm or less, The lower limit is preferably about 10 μm or more, and the thickness range is, for example, about 10 to 100 μm, preferably about 10 to 85 μm, and more preferably about 10 to 50 μm. In particular, when the barrier layer 3 is composed of a stainless steel foil, the thickness of the stainless steel foil is preferably about 85 μm or less, more preferably about 50 μm or less, further preferably about 40 μm or less, and further preferably Is about 30 μm or less, particularly preferably about 25 μm or less, the lower limit is about 10 μm or more, and the preferable thickness range is about 10 to 85 μm, about 10 to 50 μm, and more preferably about 10 to 40 μm. , More preferably about 10 to 30 μm, and further preferably about 15 to 25 μm.

Further, the barrier layer 3 is preferably subjected to chemical conversion treatment on at least one surface, preferably both surfaces, for the purpose of stabilizing adhesion, preventing dissolution and corrosion. Here, the chemical conversion treatment means a treatment for forming an acid resistant film on the surface of the barrier layer. When an acid resistant coating is formed on the surface of the barrier layer 3 of the present invention, the barrier layer 3 contains an acid resistant coating. Examples of the chemical conversion treatment include chromate chromate using a chromate compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, acetyl acetate chromate, chromium chloride, and potassium chromium sulfate. Treatment; Phosphoric acid chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid; Aminated phenol having repeating units represented by the following general formulas (1) to (4) Examples include chromate treatment using a polymer. 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 hydroxyl 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 hydroxyl 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 hydroxyl group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group is substituted. An alkyl group is mentioned. In the general formulas (1) to (4), the alkyl group and hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In formulas (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulas (1) to (4) is, for example, preferably 500 to 1,000,000, more preferably 1,000 to 20,000. ..

As a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, phosphoric acid is coated with a dispersion of fine particles of metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide or 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, examples of the cationic polymer include 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, and a 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 surface of the aluminum alloy foil (barrier layer) on the inner layer side is first subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, A degreasing treatment is performed by a well-known treatment method such as an electrolytic acid cleaning method and an acid activation method, and then Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, A treatment solution (aqueous solution) containing a metal phosphate such as Zn (zinc) phosphate and a mixture of these metal salts as a main component, or a nonmetal phosphate and a mixture of these nonmetal salts. A treatment solution (aqueous solution) as a component or a treatment solution (aqueous solution) containing a mixture of these with an aqueous synthetic resin such as an acrylic resin, a phenolic resin or a urethane resin is used for roll coating, gravure printing and dipping. An acid-resistant film can be formed by applying a known coating method such as. For example, when treated with a Cr (chromium) phosphate salt-based treatment liquid, CrPO ₄ (chromium phosphate), AlPO ₄ (aluminum phosphate), Al ₂ O ₃ (aluminum oxide), Al(OH) _x (water) Aluminum oxide), AlF _x (aluminum fluoride) and other acid resistant coatings, and when treated with a Zn (zinc) phosphate salt treatment solution, Zn ₂ PO ₄ .4H ₂ O (zinc phosphate hydrate) ), AlPO ₄ (aluminum phosphate), Al ₂ O ₃ (aluminum oxide), Al(OH) _x (aluminum hydroxide), AlF _x (aluminum fluoride) and the like.

Further, as another example of the specific method of providing the acid resistant coating, for example, at least the surface of the aluminum alloy foil on the inner layer side 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 film, a film of a phosphorus compound (for example, a phosphate type) or a chromium compound (for example, a chromic acid type) 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.

In addition, as another example of the acid resistant film, during embossing by forming an acid resistant film of a phosphorus compound (phosphate etc.), a chromium compound (chromate etc.), a fluoride, a triazine thiol compound, etc. Of delamination between the aluminum and the base material layer, and hydrogen fluoride generated by the reaction between the electrolyte and water, the aluminum surface is dissolved and corroded, especially the aluminum oxide present on the aluminum surface is dissolved and corroded. And improve the adhesion (wettability) of the aluminum surface, prevent delamination between the base material layer and aluminum during heat sealing, and in the embossed type, delaminate between the base material layer and aluminum during press molding. Shows the effect of lamination prevention. Among the substances that form an acid resistant film, an aqueous solution composed of three components of a phenolic resin, a chromium (3) fluoride compound, and phosphoric acid is applied to the aluminum surface, and dry baking is preferable.

In addition, 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 having (meth)acrylic acid or a salt thereof as a main component. Further, the cross-linking agent is preferably 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, the phosphoric acid or phosphate is preferably condensed phosphoric acid or 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 and chromate treatment in which a chromate compound, a phosphoric acid compound, and an aminated phenol polymer are combined are preferable.

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

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. Furthermore, as the acid-resistant coating, after degreasing the chemical conversion treatment surface of the barrier layer, a treatment liquid consisting of a mixture of a metal phosphate and an aqueous synthetic resin, or a mixture of a nonmetal phosphate and an aqueous synthetic resin is used. It may be formed of the following treatment liquid.

The composition of the acid resistant coating can be analyzed by, for example, time-of-flight secondary ion mass spectrometry. By analysis of the composition of the acid-resistant coating using time-of-flight secondary ion mass spectrometry, for example, at least one secondary ion composed of Ce, P, and O (eg, Ce ₂ PO ₄ ⁺ , CePO ₄ ^−, etc.) ) Or a peak derived from, for example, a secondary ion composed of Cr, P and O (for example, at least one of CrPO ₂ ⁺ and CrPO ₄ ⁻ ).

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, a chromic acid compound is added per 1 m ² of the surface of the barrier layer 3. Chromium conversion is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and aminated phenol polymer is 1. It is desirable that the content is about 0 to 200 mg, preferably about 5.0 to 150 mg.

The thickness of the acid resistant coating is not particularly limited, but from the viewpoint of the cohesive strength of the coating and the adhesion with the barrier layer or the heat-fusible resin layer, it is preferably about 1 nm to 20 μm, more preferably about 1 to 100 nm. And more preferably about 1 to 50 nm. The thickness of the acid resistant film 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 carried out by heating so as to reach 200°C. In addition, the barrier layer may be 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 before the barrier layer is subjected to the conversion treatment. By performing the degreasing treatment in this way, the chemical conversion treatment of the surface of the barrier layer can be performed more efficiently.

[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.

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 polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the heat-fusible resin layer 4 described later can also be used. .. That is, the resin forming the adhesive layer 5 may or may not include a polyolefin skeleton, and preferably includes 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. 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.

From the viewpoint of improving the adhesion between the barrier layer 3 (or the acid resistant film) and the heat-fusible resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. The acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing a polyolefin 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. As the modified polyolefin, 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 Examples include polypropylene such as random copolymers (for example, random copolymers of propylene and ethylene); terpolymers of ethylene-butene-propylene, and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

Among the acid-modified polyolefins, maleic anhydride-modified polyolefin, and maleic anhydride-modified polypropylene are particularly preferable for the adhesive layer 5.

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. More preferably, it is a thing. Preferred examples of the acid-modified polyolefin include those mentioned above.

The adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is preferable that the cured product be a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group. The adhesive layer 5 preferably contains at least one selected from the group consisting of urethane resin, ester resin, and epoxy resin, and more preferably contains urethane resin and epoxy resin. As the ester resin, for example, an amide ester resin is preferable. The amide ester resin is generally produced by the reaction of a carboxyl group and an oxazoline group. The adhesive layer 5 is more preferably a cured product of a resin composition containing at least one of these resins and the acid-modified polyolefin. In addition, when an unreacted compound of a compound having an isocyanate group, a compound having an oxazoline group, a curing agent such as an epoxy resin remains in the adhesive layer 5, the presence of the unreacted compound is determined by, for example, infrared spectroscopy, It can be confirmed by a method selected from Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

Further, from the viewpoint of further enhancing the adhesion between the barrier layer 3 (or the acid resistant coating), the heat-fusible resin layer 4, and the adhesive layer 5, the adhesive layer 5 includes an oxygen atom, a heterocycle, a C=N bond, and A cured product of the resin composition containing a curing agent having at least one selected from the group consisting of C—O—C bonds is preferable. Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C=N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Further, examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group, a curing agent having an epoxy group, and a urethane resin. The fact that the adhesive layer 5 is a cured product of a resin composition containing these curing agents means, for example, gas chromatograph mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF). -SIMS), X-ray photoelectron spectroscopy (XPS) and the like.

The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively enhancing the adhesiveness between the acid resistant coating and the adhesive layer 5, a polyfunctional isocyanate compound is preferable. The polyfunctional isocyanate compound 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 pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymerization or nurate thereof. And the like, and their mixtures and copolymers with other polymers.

The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass and 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. It is more preferably in the range.

The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Examples of commercially available products include Epocros series manufactured by Nippon Shokubai Co., Ltd.

The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesiveness between the barrier layer 3 (or the acid resistant film) and the adhesive layer 5 can be effectively enhanced.

The epoxy resin is not particularly limited as long as it is a resin that can form a crosslinked structure by an epoxy group existing in the molecule, and a known epoxy resin can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, and further preferably about 200 to 800. In the present invention, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC), which is measured under the condition that polystyrene is used as a standard sample.

Specific examples of the epoxy resin include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether. The epoxy resins may be used alone or in combination of two or more.

The ratio of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesiveness between the barrier layer 3 (or the acid resistant film) and the adhesive layer 5 can be effectively enhanced.

In the present invention, the adhesive layer 5 cures a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin, and the acid-modified polyolefin. In the case of a product, the acid-modified polyolefin functions as a main agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the epoxy resin each function as a curing agent.

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.

From the viewpoint of improving 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.

Furthermore, the adhesive layer 5 can also be suitably formed using, for example, an adhesive. Examples of the adhesive include a non-crystalline polyolefin resin (A) having a carboxyl group, a polyfunctional isocyanate compound (B), and a tertiary amine having no functional group that reacts with the polyfunctional isocyanate compound (B) ( C), the polyfunctional isocyanate compound (B) is contained in an amount of 0.3 to 10 mol of the isocyanate group with respect to 1 mol of the carboxyl group in total, and 1 mol of the carboxyl group in total with respect to 1 mol. Then, the thing formed from the adhesive composition which contains the tertiary amine (C) in the range used as 1-10 mol is mentioned. The adhesive contains a styrene-based thermoplastic elastomer (A), a tackifier (B), and a polyisocyanate (C), and contains a styrene-based thermoplastic elastomer (A) and a tackifier ( 20 to 90% by mass of the styrene-based thermoplastic elastomer (A) and 10 to 80% by mass of the tackifier (B) in a total of 100% by mass with B), and the styrene-based thermoplastic elastomer (A). Has 0.003 to 0.04 mmol/g of active hydrogen derived from an amino group or a hydroxyl group, and the tackifier (B is added to 1 mol of the active hydrogen derived from the styrene-based thermoplastic elastomer (A). The active hydrogen derived from the functional group of 1) is 0 to 15 mol, and the polyisocyanate (C) is composed of the active hydrogen derived from the styrene-based thermoplastic elastomer (A) and the active hydrogen derived from the tackifier (B). The thing formed by the adhesive composition which consists of what is contained in the range which becomes 3-150 mol of isocyanate groups with respect to 1 mol in total is also mentioned.

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer, and is preferably about 0.1 to 50 μm, more preferably about 0.5 to 40 μm. Further, when the adhesive exemplified in the adhesive layer 2 is used, it is preferably about 2 to 10 μm, more preferably about 2 to 5 μm. When the resin exemplified in the heat-fusible resin layer 4 is used, it 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 about 30 μm or less, more preferably about 0.1 to 20 μm, further preferably about 0.5 to 5 μm. In the case of an adhesive layer formed of the above-mentioned adhesive composition, the thickness after drying and curing is about 1 to 30 g/m ² . 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.

[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 the 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, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin. Be done. That is, the resin constituting 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, and the analysis method is not particularly limited. 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 (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, styrene, butadiene, isoprene, and the like. Is mentioned. 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.

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

The carboxylic acid-modified cyclic polyolefin is obtained by copolymerizing a part of monomers constituting the cyclic polyolefin in place of an α,β-unsaturated carboxylic acid or an anhydride thereof, or α,β with respect to the cyclic polyolefin. A polymer obtained by block-polymerizing or graft-polymerizing an unsaturated carboxylic acid or its anhydride. 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 acid-modified cycloolefin copolymer.

Among these resin components, carboxylic acid-modified polyolefin is preferable; and carboxylic acid-modified polypropylene is 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.

In addition, a lubricant may be present on the surface of the heat-fusible resin layer 4, if necessary, from the viewpoint of improving the moldability of the battery packaging material. The lubricant is not particularly limited, and a known lubricant can be used, and an amide lubricant is preferable. Specific examples of the lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, 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-oleylpalmitic acid 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 ethylene bisoleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N,N′-dioleyl adipate amide, 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 lubricant may be used alone or in combination of two or more.

The amount of the lubricant present on the surface of the heat-fusible resin layer 4 is not particularly limited, and from the viewpoint of enhancing the moldability of the battery packaging material, at a temperature of 24° C. and a humidity of 60%, preferably 10 to 50 mg. /M ² , and more preferably about 15 to 40 mg/m ² .

The heat-fusible resin layer 4 may contain a lubricant. Further, the lubricant present on the surface of the heat-fusible resin layer 4 may be one in which the lubricant contained in the resin forming the heat-fusible resin layer 4 is exuded, or the heat-fusible resin layer. The surface of 4 may be coated with a lubricant.

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, for example, about 100 μm or less, preferably about 85 μm or less, more preferably about 15 to 85 μm. Is mentioned. Note that, for example, when the thickness of the adhesive layer 5 is 10 μm or more, the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm. When the thickness of the adhesive layer 5 is less than about 10 μm, the thickness of the heat-fusible resin layer 4 is preferably about 20 μm or more, more preferably about 35 to 85 μm.

[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. When the surface coating layer 6 is provided, the surface coating layer 6 is the outermost layer of the battery packaging material.

The surface coating layer 6 can be formed of, for example, polyvinylidene chloride, polyester, 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, a two-component curing type epoxy resin and the like. Moreover, you may mix|blend an additive with the surface coating layer.

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, and 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. As the additive, specifically, 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, 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 surface of the additive may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment.

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 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 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 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 The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate obtained by laminating each layer having a predetermined composition is obtained, and at least a base material layer and an adhesive. A layer, a barrier layer, and a heat-fusible resin layer are laminated in this order to obtain a laminate, and in thermomechanical analysis for measuring the displacement of the probe, the laminate The probe is installed on the surface of the adhesive layer of the cross section, the deflection of the probe at the start of measurement is set to -4V, and the temperature is raised from 5°C/min to 40°C to 350°C. A method for producing a battery packaging material is one in which the temperature at which the amount of displacement of the probe becomes maximum when heated is 190° C. or higher and 320° C. or lower. In the method for manufacturing a battery packaging material of the present invention, the details of the base material layer 1, the adhesive layer 2, the barrier layer 3, and the heat-fusible resin layer 4 are as described above. Moreover, you may provide the above-mentioned adhesive layer 5 and the surface coating layer 6 as needed.

An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminated body (hereinafter, also referred to as “laminated body A”) in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in order is formed. To form the laminate A, specifically, the base layer 1 or the barrier layer 3 is coated with the adhesive used for forming the adhesive layer 2 by a coating method such as a gravure coating method or a roll 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 dried. At this time, when the barrier layer 3 is laminated, at least one surface of the barrier layer 3 on which the above-described acid resistant film is formed in advance may be used.

Next, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated on the barrier layer 3 of the laminate A. As a method of providing the adhesive layer 5 on the barrier layer 3, for example, a method such as a gravure coating method, a roll coating method, an extrusion laminating method or the like is used for the resin component forming the adhesive layer 5 on the barrier layer 3 of the laminate A. It may be applied. As a method of providing the adhesive layer 5 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. 4 is a 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, a method of laminating the adhesive layer 5 on the barrier layer 3 of the laminate A by an extrusion method or a solution coating method, a method of drying at a high temperature, and a method of 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 laminate 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 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer can be formed, for example, by 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.

As described above, the surface coating layer 6/base material layer 1/adhesive layer 2/barrier layer 3 provided with an acid resistant coating on at least one surface as needed/provided as necessary A laminated body composed of the adhesive layer 5/the heat-fusible resin layer 4 is formed, and in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as necessary, a heat roll is further added. It may be subjected to heat treatment such as contact type, hot air type, near or far infrared ray type.

In the battery packaging material of the present invention, each layer constituting the laminate improves or stabilizes film forming properties, lamination processing, suitability for final product secondary processing (pouching, embossing), etc., if necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment and ozone treatment may be performed.

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

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte, in the battery packaging material of the present invention, in a state where the metal terminals connected to each of the positive electrode and the negative electrode are projected outward, 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, Provided is a battery using the packaging material. When the battery element is housed in a package formed of the battery packaging material of the present invention, the heat-fusible resin portion of the battery packaging material of the present invention is placed inside (the surface that contacts the battery element). Then, the package is formed.

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.

Since automobiles, mobile devices, and the like are sometimes used in harsh environments such as moist heat environments, the batteries used in such environments are also required to have improved durability. In the battery packaging material of the present invention, the adhesive layer 2 located between the base material layer 1 and the barrier layer 3 can improve the durability of the battery packaging material in a wet heat environment. Therefore, the battery packaging material of the present invention is particularly useful as a packaging material used for, for example, a vehicle battery or a mobile device battery.

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

<Manufacturing of packaging materials for batteries>
A packaging material for a battery was manufactured so as to have the laminated structure shown in Table 1. In Table 1, ON is a biaxially stretched nylon film, PET is a biaxially stretched polyethylene terephthalate film, and DL is a base compound containing a polyester polyol composed of a polybasic acid component and a polyhydric alcohol component and a polyfunctional compound. A two-component urethane adhesive that is a curing agent containing an isocyanate component is cured, ALM is an aluminum alloy foil, and PPa is an acid-modified polypropylene resin (an unsaturated carboxylic acid graft-modified with an unsaturated carboxylic acid. Modified random polypropylene) and PP is polypropylene (random copolymer). Further, in Table 1, the numerical value described in each layer means the thickness (μm) of the layer, and for example, “ON25” means “a biaxially stretched nylon film having a thickness of 25 μm”. ..

Table 1 shows the positional isomer content ratio (isophthalic acid:terephthalic acid) of the aromatic polybasic acid component contained in the polybasic acid component used for forming the adhesive layer. The specific manufacturing method of each battery packaging material is as follows.

<Examples 1 to 6 and Comparative Examples 1 to 2>
In Examples 1 to 6 and Comparative Examples 1 and 2, a biaxially stretched nylon film was used as the resin film forming the base material layer. One side of the biaxially stretched nylon film is corona treated. In Examples 1 to 6 and Comparative Examples 1 and 2, erucic acid amide was applied as a lubricant to the surface of the biaxially stretched nylon film that was not subjected to corona treatment (the amount applied was 10 mg/m ² ). On the other hand, a polybasic acid component (60 parts by mass) and a polyhydric alcohol component (40 parts by mass) having the positional isomer content ratios shown in Table 1 are formed on the surface of the biaxially stretched nylon film subjected to corona treatment. And a thickness of 3 μm after curing an adhesive layer made of a two-component urethane adhesive of a main agent (100 parts by mass) containing a polyester polyol and a curing agent containing a polyfunctional isocyanate component (15 parts by mass). It was applied so that Next, the aluminum alloy foil is laminated on the adhesive layer side of the base material layer and the chemical conversion treatment surface of the aluminum alloy foil, and after pressure heating and bonding, aging treatment is carried out to obtain the base material layer/ A laminate was produced in which the adhesive layer/aluminum alloy foil was laminated in order. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method such that a coating liquid of a phenol resin, a chromium fluoride compound, and phosphoric acid was applied so that the coating amount of chromium was 10 mg/m ² (dry mass). It was done by applying to both sides of the foil and baking.

<Examples 7 to 12 and Comparative Examples 3 to 4>
In Examples 7 to 12 and Comparative Examples 3 to 4, the polybasic acid component (60 parts by mass) in which the biaxially stretched polyethylene terephthalate film and the biaxially stretched nylon film were composed of the positional isomer content ratios shown in Table 1 was used. ) And a polyhydric alcohol component (40 parts by mass) and a main component (100 parts by mass) containing a polyester polyol and a curing agent (15 parts by mass) containing a polyfunctional isocyanate component. The laminated film was used as the base material layer. One side of the biaxially stretched polyethylene terephthalate film and both sides of the biaxially stretched nylon film were corona treated, and the corona treated surface of the biaxially stretched polyethylene terephthalate film and the biaxially stretched nylon film were bonded together. In Examples 7 to 12 and Comparative Examples 3 and 4, erucic acid amide was applied as a lubricant to the surface of the biaxially stretched polyethylene terephthalate film that had not been subjected to the corona treatment (the application amount was 10 mg/m ² ). Polyester polyol composed of a polybasic acid component (60 parts by mass) and a polyhydric alcohol component (40 parts by mass) having the positional isomer content ratios shown in Table 1 on the biaxially stretched nylon film side of the base material layer. An adhesive layer composed of a two-component urethane adhesive consisting of a main agent containing 100 parts by mass of (1) and a curing agent containing a polyfunctional isocyanate component (15 parts by mass) was applied so that the thickness after curing was 3 μm. Next, the aluminum alloy foil is laminated on the adhesive layer side of the base material layer and the chemical conversion treatment surface of the aluminum alloy foil, and after pressure heating and bonding, aging treatment is carried out to obtain the base material layer/ A laminate was produced in which the adhesive layer/aluminum alloy foil was laminated in order. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method such that a coating liquid of a phenol resin, a chromium fluoride compound, and phosphoric acid was applied so that the coating amount of chromium was 10 mg/m ² (dry mass). It was done by applying to both sides of the foil and baking.

<Examples 13 to 18 and Comparative Examples 5 to 6>
In Examples 13 to 18 and Comparative Examples 5 to 6, a biaxially stretched polyethylene terephthalate film (PET film) was used as the resin film forming the base material layer. One side of the PET film is corona treated. On the corona-treated surface of the PET film, a main agent containing a polyester polyol composed of a polybasic acid component (60 parts by mass) and a polyhydric alcohol component (40 parts by mass) having the positional isomer content ratios shown in Table 1. (100 parts by mass) and a curing agent (15 parts by mass) containing a polyfunctional isocyanate component were applied as an adhesive layer composed of a two-component urethane adhesive so that the thickness after curing would be 3 μm. In Examples 13 to 18 and Comparative Examples 5 and 6, erucamide was applied as a lubricant on the surface of the biaxially stretched polyethylene terephthalate film that had not been subjected to the corona treatment (the amount applied was 10 mg/m ² ). Next, an aluminum alloy foil is prepared, the adhesive layer side of the base material layer and the chemical conversion treatment surface of the aluminum alloy foil are laminated, and after pressure heating and bonding, aging treatment is carried out to obtain a base material. A laminate was prepared in which layers/adhesive layer/aluminum alloy foil were laminated in order. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method such that a coating liquid of a phenol resin, a chromium fluoride compound, and phosphoric acid was applied so that the coating amount of chromium was 10 mg/m ² (dry mass). It was done by applying to both sides of the foil and baking.

Next, in Examples 1 to 18 and Comparative Examples 1 to 6, an acid-modified polypropylene resin (unsaturated carboxylic acid graft-modified random polypropylene graft-modified with unsaturated carboxylic acid) and an adhesive layer are separately heat-bonded. By co-extruding polypropylene (random copolymer) constituting the resin layer, a two-layer co-extruded film composed of an adhesive layer having a thickness of 22 μm and a heat-fusible resin layer having a thickness of 22 μm was produced. Next, the laminate comprising the above-mentioned base material layer/adhesive layer/aluminum alloy foil was laminated on the aluminum alloy foil side so that the adhesive layer of the two-layer coextruded film prepared above was in contact with the aluminum alloy foil. By heating, a laminate was obtained in which the base material layer/adhesive layer/aluminum alloy foil/adhesive layer/heat-fusible resin layer were laminated in order. The obtained laminated body was once cooled and then subjected to heat treatment to obtain each battery packaging material. The surface of the heat-fusible resin layer was coated with erucic acid amide as a lubricant (coating amount was 10 mg/m ² ).

<Measurement of mass ratio of isophthalic acid and terephthalic acid>
The mass ratio of isophthalic acid and its derivative and terephthalic acid and its derivative in the adhesive layer was measured by the following measuring method using a gas chromatograph mass spectrometer. First, as a pretreatment, a methylating agent was used to derivatize the adhesive constituting the adhesive layer. An example of the derivatization procedure is as follows. Next, using a gas chromatograph mass spectrometer (Gas Chromatograph Mass Spectrometer (GC/MS) QP2010 manufactured by Shimadzu Corp.), analysis was carried out under measurement conditions capable of separating retention times of isophthalic acid and terephthalic acid.
[Procedure for derivatization]
A 25% methanol solution of tetramethylammonium hydroxide (TMAH) was prepared as a methylating agent. A glass tube was charged with about 5 mg of a sample and about 3 μl of a methylating agent. Next, the glass tube was melted with a gas burner and capped. Next, the electric furnace was heated at 200 to 300° C. for about 15 minutes. Derivatization proceeds during heating. Next, the glass tube was opened and the sample was taken out.
[Measurement condition]
Column: UA-5 FRONTIER LAB (stationary phase 5% diphenyl-95% dimethylpolysiloxane, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm)
Oven temperature: held at 50°C for 5 minutes and heated to 320°C at 10°C/min Ionization method: electron impact ionization method (EI method)
Detector: Quadrupole detector Thermal decomposition temperature: 320°C for 1 min
Injection temperature: 320°C
Quantitative method: Absolute calibration curve method Structural isomers of benzenedicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid, but the retention time under these measurement conditions is phthalic acid, terephthalic acid, and isophthalic acid. Will be in order.

<Measurement of softening point of adhesive layer>
A probe was installed on the surface of the adhesive layer of the cross section of each battery packaging material (the tip radius of the probe was 30 nm or less, the deflection setting value of the probe was -4 V), and the probe was heated from 40°C to 350°C ( The temperature rise rate was 5° C./min), and the displacement amount of the probe was measured. The details of the measurement conditions are as follows. As an atomic force microscope equipped with a nano-thermal microscope composed of a cantilever with a heating mechanism, an afm plus system manufactured by ANASYS INSTRUMENTS is used, and as a probe, a cantilever ThermoLever AN2-200 manufactured by ANASYS INSTRUMENTS (spring constant 0.1 to 200). 0.5 N/m) was used. The average value obtained by changing the measurement position and measuring N=3 was used. The measurement results are shown in Table 1, with the temperature at which the amount of displacement is maximum taken as the softening point of the adhesive layer. Three kinds of attached samples (polycaprolactam (melting point 55° C.), polyethylene (melting point 116° C.), polyethylene terephthalate (melting point 235° C.)) were used for calibration, applied voltage 0.1 to 10 V, speed 0.2 V/ The setting value of the second and the deflection was -4V. For each of the three calibration samples, the measurement position was changed, and the average value of N=3 measurements was used.

<Measurement of critical forming depth>
Each of the battery packaging materials obtained above was cut into 150 mm (TD: Transverse Direction)×90 mm (MD: Machine Direction) strips, which were used as test samples. The MD of the battery packaging material corresponds to the rolling direction (RD: Rolling Direction) of the aluminum alloy foil, and the TD of the battery packaging material corresponds to the TD of the aluminum alloy foil. Further, the TD is the direction perpendicular to the same plane as MD and RD. The rolling direction of the aluminum alloy foil can be confirmed by the rolling mark of the aluminum alloy foil. In a 25° C. environment, this sample was molded in a rectangular shape in plan view (female mold, with a surface of JIS B 0659-) having a rectangular diameter of 31.6 mm (MD)×54.5 mm (TD). 1: 2002 Annex 1 (reference) The maximum height roughness (nominal value of Rz) specified in Table 2 of the surface roughness standard piece for comparison is 3.2 μm, corner R2.0 mm, ridge R1.0 mm. ) And a molding die having a rectangular shape in plan view corresponding to this (male, surface is defined in Table 2 of JIS B 0659-1:2002 Annex 1 (reference) comparative surface roughness standard piece, The maximum height roughness (nominal value of Rz) is 1.6 μm, using a corner R2.0 mm and a ridgeline R1.0 mm, a pressing pressure (contact pressure) of 0.25 MPa and a forming depth of 0.5 mm to 0. The forming depth was changed in increments of 0.5 mm, and cold forming (1 step drawing-in) was performed on 10 samples each. At this time, the test sample was placed on the female mold and molding was performed so that the heat-fusible resin layer side was located on the male mold side. The clearance between the male and female molds was 0.3 mm. The cold-formed sample was exposed to light with a penlight in a dark room, and it was confirmed whether the aluminum alloy foil had pinholes or cracks due to the light transmission. Amm is the deepest molding depth where pinholes and cracks do not occur in all 10 samples in the aluminum alloy foil, and the number of samples where pinholes occur in the shallowest molding depth where pinholes occur in the aluminum alloy foil Was defined as B and the value calculated by the following formula was defined as the limit forming depth of the battery packaging material. The results are shown in Table 1.
Limit forming depth = Amm + (0.5mm/10 pieces) x (10 pieces-B pieces)

<Durability evaluation in moist heat environment after molding>
Each battery packaging material obtained above was cut into 150 mm (TD)×100 mm (MD) strips, which were used as test samples. 10 test samples were prepared for each. As described above, the MD of the battery packaging material corresponds to the rolling direction (RD) of the aluminum alloy foil, and the TD of the battery packaging material corresponds to the TD of the aluminum alloy foil. Further, the TD is the direction perpendicular to the same plane as MD and RD. The rolling direction of the aluminum alloy foil can be confirmed by the rolling mark of the aluminum alloy foil. The mold is a male mold of 31.6 mm (MD) x 54.5 mm (TD) with a rectangular shape in a plan view (the surface is JIS B 0659-1:2002 Annex 1 (reference) of a surface roughness standard piece for comparison. The maximum height roughness (nominal value of Rz) specified in Table 2 is 1.6 μm, the corner R2.0 mm, the ridgeline R1.0 mm, and the female mold having a clearance of 0.5 mm between the male mold ( The surface has a maximum height roughness (nominal value of Rz) of 3.2 μm, which is specified in Table 2 of JIS B 0659-1:2002 Annex 1 (reference) Comparative surface roughness standard piece. A mold composed of 0.0 mm and a ridgeline R of 1.0 mm was used. The test sample was placed on the female mold so that the heat-fusible resin layer side was located on the male mold side. Each of the test samples was pressed at a surface pressure of 0.25 MPa so as to have the forming depth shown in Table 1, and cold-formed (pull-in one-stage forming). Next, the sample after cold forming was placed in a constant temperature and humidity chamber at a temperature of 65° C. and a relative humidity of 90% RH, and allowed to stand for 72 hours. The molded sample was taken out from the constant temperature and humidity chamber, and visually checked for floating (peeling of the base layer) between the base material layer and the aluminum alloy foil. Table 1 shows the proportion of the samples that had been removed.

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... Battery packaging material

Claims (7)

At least a base material layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer is composed of a laminate provided in this order,
The adhesive layer is formed of a polyurethane adhesive containing a main component containing a polyol component and a curing agent containing a polyfunctional isocyanate component,
The polyol component contains a polybasic acid component and a polyhydric alcohol component,
The polybasic acid component is a battery packaging material containing the isophthalic acid and its derivative and the terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10. The battery packaging material according to claim 1, wherein the adhesive layer contains a coloring agent. The packaging material for a battery according to claim 1, wherein the barrier layer has a thickness of 10 μm or more and 100 μm or less. The battery packaging material according to claim 1, wherein the barrier layer is made of an aluminum alloy foil. The packaging material for a battery according to claim 1, wherein the base layer contains at least one of polyester and polyamide. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 5. At least, a substrate layer, an adhesive layer, a barrier layer, and a step of obtaining a laminate by laminating the heat-fusible resin layer in this order,
The adhesive layer is formed of a polyurethane adhesive containing a main component containing a polyol component and a curing agent containing a polyfunctional isocyanate component,
The polyol component contains a polybasic acid component and a polyhydric alcohol component,
The polybasic acid component contains the isophthalic acid and its derivative and the terephthalic acid and its derivative in a mass ratio of 35:65 to 90:10,
Manufacturing method of battery packaging material.

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