JP6662498B2 - Battery packaging material, method for producing the same, and battery - Google Patents

Description

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

  Conventionally, various types of batteries have been developed, but in all batteries, a packaging material is 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 the performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like has improved, batteries have been required to have various shapes and to be thinner and lighter. However, a metal battery packaging material that has been frequently used in the past has a drawback that it is difficult to keep up with 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 layer / barrier layer / heat-fusible resin layer is sequentially laminated. The body has been proposed.

  In such a battery packaging material, generally, a concave portion is formed by cold molding, and a battery element such as an electrode or an electrolytic solution is disposed in a space formed by the concave portion. Is thermally welded to obtain a battery in which a battery element is accommodated inside a battery packaging material. However, such a film-shaped packaging material has a disadvantage that it is thinner than a metal packaging material, and pinholes and cracks are easily generated during molding. If 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 a short circuit. It is indispensable for the battery packaging material to have characteristics that pinholes and the like hardly occur at the time of molding, that is, have excellent moldability.

  In order to enhance the moldability of the film-shaped battery packaging material, various studies have been made focusing on an adhesive layer for bonding a metal layer. For example, Patent Literature 1 discloses 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. And 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, so that a deeper molding can be achieved. It is disclosed that a highly reliable packaging material can be obtained.

  Conventionally, as typified by Patent Literature 1, in a battery packaging material formed of a film-like laminate, a technique for improving the moldability by focusing on a compounding component of an adhesive layer for bonding a metal layer and another layer is disclosed. Many studies have been made.

JP 2008-287971 A

  The present inventors have studied that, although the adhesiveness between the outer layer and the metal layer is improved by the second adhesive layer of Patent Document 1, the effect of improving the moldability may be insufficient. It became clear.

  In addition, automobiles and mobile devices are sometimes used in a harsh environment such as a moist heat environment, and batteries used in such an environment are also required to have improved durability. Therefore, in the battery packaging material, further, when the battery packaging material after molding is placed in a moist heat environment, durability in a moist heat environment where peeling between the outer layer and the metal layer hardly occurs is required. 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 conducted intensive studies in order to solve the above problems. As a result, at least, a base layer, an adhesive layer, a barrier layer, and a laminate having a heat-fusible resin layer in this order, and in thermomechanical analysis for measuring the displacement of the probe, The probe was set on the surface of the adhesive layer in the cross section of the laminate, and the probe was set at 40 ° C. under the condition that the set value of the deflection of the probe at the start of measurement was −4 V and the temperature was raised at a rate of 5 ° C./min. The battery packaging material in which the temperature at which the displacement of the probe is maximum when heated to a temperature of from 350 ° C. to 190 ° C. is excellent in moldability and is durable in a moist heat environment after molding. We found that it was also excellent. The present invention has been completed by further study based on these findings.

That is, the present invention provides the following aspects of the invention.
Item 1. At least, a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate including in this order,
In the thermomechanical analysis for measuring the displacement of the probe, the probe is set on the surface of the adhesive layer in the cross section of the laminate, and the set value of the deflection of the probe at the start of the measurement is -4 V, and the temperature rise rate is 5 A packaging material for a battery, wherein a temperature at which the displacement of the probe is maximum when the probe is heated from 40 ° C. to 350 ° C. under a condition of ° C./min is 190 ° C. or more and 320 ° C. or less.
Item 2. Item 4. The battery packaging material according to item 1, wherein the adhesive layer is a cured product of 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.
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 packaging material for a battery according to any one of Items 1 to 3, wherein the adhesive layer contains a coloring agent. Item 5. Item 5. The battery packaging material according to any one of Items 1 to 4, wherein the thickness of the barrier layer is 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 layer contains at least one of polyester and polyamide.
Item 8. A battery, wherein 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 of the probe, the probe is set on the surface of the adhesive layer in the cross section of the laminate, and the set value of the deflection of the probe at the start of the measurement is -4 V, and the temperature rise rate is 5 A method for producing a packaging material for a battery, wherein a temperature at which the displacement of the probe is maximum when the probe is heated from 40 ° C. to 350 ° C. under a 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 and its derivative and terephthalic acid and its derivative at 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, and a heat-fusible resin layer, in a battery packaging material composed of a laminate including in this order, excellent moldability. The present invention can provide a packaging material for a battery that has excellent durability in a wet heat environment after molding. Further, according to the present invention, it is also possible to provide a method for producing the battery packaging material, and a battery using the battery packaging material.

It is a figure showing an example of the section structure of the battery packaging material of the present invention. It is a figure showing an example of the section structure of the battery packaging material of the present invention. It is a figure showing an example of the section structure of the battery packaging material of the present invention.

  The battery packaging material of the present invention is composed of a laminate including at least a substrate 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 to be performed, the probe is placed on the surface of the adhesive layer in the cross section of the laminate, and the set value of the deflection of the probe at the start of the measurement is -4 V, under the conditions of a temperature rising rate of 5 ° C./min. When the probe is heated from 40 ° C. to 350 ° C., the temperature at which the displacement of the probe becomes maximum is 190 ° C. or more and 320 ° C. or less. With the battery packaging material of the present invention having such a configuration, it has excellent moldability and excellent durability in a moist heat environment after molding. For this reason, the battery packaging material of the present invention can be suitably used particularly as a packaging material used for batteries for vehicles and batteries for mobile devices. Hereinafter, the battery packaging material of the present invention will be described in detail.

  In this specification, a numerical range indicated by “to” means “over” and “below”. 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 The battery packaging material of the present invention comprises at least a base layer 1, an adhesive layer 2, a barrier layer 3, and a heat-fusible resin layer, as shown in FIGS. 1 to 3, for example. 4 in this order. In the battery packaging material of the present invention, the base material layer 1 is on the outermost layer side, and the heat-fusible resin layer 4 is on the innermost layer. That is, when assembling the battery, 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, between the barrier layer 3 and the heat-fusible resin layer 4, for the purpose of improving the adhesiveness between them, and the like, If necessary, the adhesive layer 5 may be provided. Further, as shown in FIG. 3, the battery packaging material of the present invention may have a barrier layer of the base material layer 1 as required for the purpose of improving design, electrolytic solution resistance, abrasion resistance and moldability. A surface coating layer 6 may be provided on the side opposite to the layer 3 side, if necessary.

  The thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited. However, the thickness of the battery packaging material is reduced to increase the energy density of the battery, while the moldability and the shape after molding are reduced. From the viewpoint of a battery packaging material having excellent wet heat resistance, for example, 180 μm or less, preferably 150 μm or less, more preferably about 60 to 180 μm, and still more preferably about 60 to 150 μm.

2. Each layer forming the battery packaging material [base 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 for forming the base material layer 1 is not particularly limited as long as it has insulating properties.

  Examples of the material forming the base layer 1 include resin films such as polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenolic resin, polycarbonate, and mixtures and copolymers thereof. . Among these, polyester and polyamide are preferred, and biaxially stretched polyester and biaxially stretched polyamide are more preferred.

  As the polyester, specifically, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymerized polyester having ethylene terephthalate as the main unit of the repeating unit, and butylene terephthalate as the main unit of the repeating unit And the like. Examples of the copolymerized polyester mainly composed of ethylene terephthalate as a repeating unit include copolymer polyesters (hereinafter, referred to as polyethylene (terephthalate / isophthalate)) in which ethylene terephthalate is mainly composed of repeating units and polymerized with ethylene isophthalate. Polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate) and the like. Further, as the copolymer polyester containing butylene terephthalate as a main component of a repeating unit, specifically, a copolymer polyester (hereinafter referred to as polybutylene (terephthalate / isophthalate)) polymerizing butylene isophthalate with butylene terephthalate as a main component of a repeating unit , Polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, and the like. These polyesters may be used alone or in a combination of two or more. Polyester is excellent in electrolytic solution resistance and has an advantage that whitening or the like hardly occurs upon adhesion of the electrolytic solution, and thus is preferably used as a material for forming the base material layer 1.

  Specific examples of the polyamide include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid and T represents terephthalic acid), polyamide MXD6 (polymer Polyamide containing an aromatic compound such as taxylylene adipamide); alicyclic polyamide such as polyaminomethylcyclohexyl adipamide (PACM6); and copolymerization of a lactam component and an isocyanate component such as 4,4'-diphenylmethane-diisocyanate. Polyamide , Polyester amide copolymer and polyether ester amide copolymer is a copolymer of a copolyamide and a polyester or a polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used alone or in a combination of two or more. The stretched polyamide film is excellent in stretchability, can prevent whitening due to resin cracking of the base layer 1 during molding, and is suitably used as a material for forming the base layer 1.

  The base 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. Specific examples include 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. When the base material layer 1 has a multilayer structure, a laminate of a biaxially stretched polyamide film and a biaxially stretched polyester film, a laminate of a plurality of laminated biaxially stretched polyamide films, and a laminate of a plurality of laminated biaxially stretched polyester films The body is preferred. For example, when the base material layer 1 is formed from a two-layer resin film, a structure in which a polyester film and a polyester film are laminated, a structure in which a polyamide film and a polyamide film are laminated, or a structure in which a polyester film and a polyamide film are laminated It is more preferable to adopt a configuration in which a polyethylene terephthalate film and a polyethylene terephthalate film are laminated, a configuration in which a nylon film and a nylon film are laminated, or a configuration in which a polyethylene terephthalate film and a nylon film are laminated. In addition, since the polyester is unlikely to be discolored when, for example, the electrolytic solution adheres to the surface, 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 multilayer 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, the two or more resin films may be laminated via a layer having an adhesive component such as an adhesive or an adhesive resin. The amount and the amount are the same as in the case of the adhesive layer 2 described later. The method for laminating two or more layers of resin is not particularly limited, and a known method can be employed, for example, a dry lamination method, a sandwich lamination method, a co-extrusion lamination method, and the like, and a dry lamination method is preferable. Can be When laminating by a dry lamination method, it is preferable to use a urethane-based 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 reducing the thickness of the battery packaging material, the lower limit is preferably about 5 μm. The above is more preferably about 10 μm or more, and 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 made of a biaxially stretched polyamide film, particularly a biaxially stretched nylon film.

  The thickness of the polyamide film layer is not particularly limited, but from the viewpoint of exhibiting high insulation while reducing the thickness of the battery packaging material, the lower limit is preferably about 5 μm or more, 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.

  When the base material layer 1 has a multilayer structure, the order of lamination of 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 enhancing the moldability of the battery packaging material. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of the amide-based lubricant include the same ones as exemplified in 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 .

  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 obtained by exuding the lubricant contained in the resin constituting the base material layer 1 or one obtained by applying the lubricant to the surface of the base material layer 1 It may be.

  The thickness (total) of the base material layer 1 is not particularly limited as long as it functions as a base material layer, and 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 bonding the base material layer 1 and the barrier layer 3, and further improves the formability of the battery packaging material. This layer is provided to improve the durability in a wet heat environment.

  In the battery packaging material of the present invention, in the thermomechanical analysis for measuring the displacement of the probe, the probe is placed on the surface of the adhesive layer 2 in the cross section of the laminate constituting the battery packaging material, and the measurement is started. When the probe is heated from 40 ° C. to 350 ° C. under the condition that the set value of the deflection of the probe is −4 V and the temperature rise rate is 5 ° C./min, the temperature at which the displacement of the probe becomes the maximum is bonded. The softening point of the agent layer 2 is 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. The cured product is preferably 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 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 moist 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 as follows: , Preferably about 35:65 to 90:10, more preferably about 40:60 to 85:15.

  Examples of the derivatives of isophthalic acid and terephthalic acid include, for example, carboxylic acid derivatives. Examples of the carboxylic acid derivative include an acid halide, an acid anhydride, and an ester. Examples of the derivatives of isophthalic acid and terephthalic acid include those having a substituent on the benzene ring of isophthalic acid and terephthalic acid, respectively. Examples of the substituent include, but are not particularly limited to, an alkyl group (for example, a methyl group, an ethyl group, and a propyl group), a halogen atom, a hydroxyl group, and an amino group. The derivative of isophthalic acid and the derivative of terephthalic acid may each be a carboxylic acid derivative and may have a substituent on the benzene ring.

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

<Measurement of mass ratio of isophthalic acid and its derivative to terephthalic acid and its derivative>
First, as a pretreatment, the adhesive constituting the adhesive layer is derivatized using a methylating agent. An example of the derivatization procedure is as follows. Next, using a gas chromatograph mass spectrometer (for example, a gas chromatograph mass spectrometer (GC / MS) QP2010 manufactured by Shimadzu Corporation) under the measurement conditions that can separate the retention time of isophthalic acid, terephthalic acid, and their derivatives. Perform analysis. Examples of the measurement conditions are as follows.
[Derivatization procedure]
As a methylating agent, a 25% methanol solution of tetramethylammonium hydroxide (TMAH) is prepared. About 5 mg of the sample and about 3 μl of the methylating agent are sealed in a glass tube. Next, the glass tube is melted with a gas burner and plugged. Next, heating is performed for about 15 minutes at 200 to 300 ° C. in an electric furnace. During heating, derivatization proceeds. Next, the glass tube is opened and the sample is taken out.
[Measurement condition]
Column: UA-5 manufactured by FRONTIER LAB (stationary phase 5% diphenyl-95% dimethylpolysiloxane), inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm
Oven temperature: Hold at 50 ° C. for 5 minutes and raise the temperature to 320 ° C. at 10 ° C./min. Ionization method: Electron impact ionization method (EI method)
Detector: Quadrupole detector Pyrolysis temperature: 320 ° C for 1 min
Injection temperature: 320 ° C
Assay: Either the absolute calibration method or the internal standard method can be used.
Structural isomers of benzenedicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. The retention time (retention time) under these measurement conditions is phthalic acid, terephthalic acid, and isophthalic acid in this order.

  Further, from the same viewpoint, the ratio 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 still more preferably 50 to 90% by mass. Is mentioned.

  The polybasic acid component may contain isophthalic acid and its derivatives and terephthalic acid and its derivatives, and further includes naphthalenedicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, and anhydride. Tetrahydrophthalic acid, hexahydrophthalic anhydride, maleic anhydride, itaconic anhydride and ester compounds thereof can be used 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, and 1,4-cyclohexanedimethanol. , Trimethylolpropane, glycerin, 1,9-nanonediol, 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. The polyfunctional isocyanate component is not particularly limited, but is preferably pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or the like. Examples thereof include those polymerized or nulated, mixtures thereof, and copolymers with other polymers.

  In the adhesive layer 2, the content ratio of the main agent and the curing agent is particularly determined as long as 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 wet 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. About 5 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 component is preferably About 1 to 25, more preferably about 10 to 20 can be mentioned.

  As described above, in the battery packaging material of the present invention, in the thermomechanical analysis for measuring the displacement of the probe, the probe is set on the surface of the adhesive layer 2 in the cross section of the laminate, and the probe diff at the start of the measurement. When the probe is heated from 40 ° C. to 350 ° C. under the conditions of a set value of −4 V and a heating rate of 5 ° C./min, the temperature at which the displacement of the probe becomes maximum is determined by 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 has a weight ratio of isophthalic acid and its derivative to terephthalic acid and its derivative 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 the durability of the battery packaging material in a moist heat environment after molding can be more suitably improved. it can.

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

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

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

  Further, the adhesive layer 2 may include a coloring agent. When the adhesive layer 2 contains a coloring agent, the packaging material for a battery can be colored. Known coloring agents such as pigments and dyes can be used. Further, only one type of colorant may be used, or two or more types may be mixed and used.

  For example, specific examples of inorganic pigments preferably include carbon black and titanium oxide. Specific examples of the organic pigments preferably include azo pigments, phthalocyanine pigments, and condensed polycyclic pigments. Examples of the 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; and phthalocyanine pigments include copper phthalocyanine pigments and non-soluble azo pigments. Blue pigments and green pigments are exemplified as metal phthalocyanine pigments, and dioxazine violet and quinacridone violet are exemplified as condensed polycyclic pigments. 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 size of the pigment is not particularly limited, and may be, for example, about 0.05 to 5 μm, and preferably about 0.08 to 2 μm. The average particle size of the pigment is a median size measured by a laser diffraction / scattering type 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 may be, for example, about 5 to 60% by mass.

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

  The adhesive layer 2 may be formed by curing the adhesive layer 2 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 90 ° C. About 144 hours, more preferably about 48 to 120 hours.

[Coloring layer]
The coloring layer is a layer provided as needed between the base material layer 1 and the adhesive layer 2 or between the adhesive layer 2 and the barrier layer 3 (not shown). By providing the coloring 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 coloring agents such as pigments and dyes can be used. Further, only one type of colorant may be used, or two or more types may be mixed and used.

  Specific examples of the coloring agent included in the coloring layer include the same coloring agents 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 functions as a barrier layer for preventing the invasion of water vapor, oxygen, light, and the like into the battery, in addition to improving the strength of the battery packaging material. The barrier layer 3 can be formed by a metal foil, a metal vapor-deposited film, an inorganic oxide vapor-deposited film, a carbon-containing inorganic oxide vapor-deposited film, a film provided with these vapor-deposited layers, and the like. Preferably, there is. Specific examples of the metal forming the barrier layer 3 include an aluminum alloy, stainless steel, and titanium steel, and preferably an aluminum alloy. The barrier layer 3 can be formed by a metal foil, metal deposition, or the like, is preferably formed of a metal foil, and is more preferably formed of an aluminum alloy foil or a stainless steel foil. From the viewpoint of preventing generation of wrinkles and pinholes in the barrier layer 3 during the production of the battery packaging material, for example, an annealed aluminum alloy foil (JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H). -O, JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O), and more preferably a soft aluminum alloy foil.

  Examples of the stainless steel foil include an austenitic stainless steel foil and a ferrite stainless steel foil. The stainless steel foil is preferably made of austenitic stainless steel.

  Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L and the like, and among them, SUS304 is particularly preferable.

  The thickness of the barrier layer 3 is not particularly limited as long as it functions as a barrier layer such as water vapor, but the upper limit is preferably about 100 μm or less, more preferably about 85 μm or less, and still more 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 made of stainless steel foil, the thickness of the stainless steel foil is preferably about 85 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, and still more preferably. Is about 30 μm or less, particularly preferably about 25 μm or less, and 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 still more preferably about 15 to 25 μm.

  Further, it is preferable that at least one surface, preferably both surfaces, of the barrier layer 3 is subjected to a chemical conversion treatment in order to stabilize adhesion, prevent dissolution or corrosion, and the like. Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of the barrier layer. When an acid-resistant film is formed on the surface of the barrier layer 3 of the present invention, the barrier layer 3 includes an acid-resistant film. As the chemical conversion treatment, for example, chromate chromate using a chromate compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, acetyl chromate, chromium chloride, potassium chromium sulfate, etc. Treatment; Phosphate chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; Aminated phenol having a repeating unit represented by the following general formulas (1) to (4) Chromate treatment using a polymer may be mentioned. 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. Is also good.

In the general 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 a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include, for example, a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, A linear or branched C1-C4 substituted one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, a 4-hydroxybutyl group; And an alkyl group. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a 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 from 500 to 1,000,000, and more preferably from 1,000 to 20,000. .

  In addition, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a coating in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide or fine particles of barium sulfate are dispersed in phosphoric acid, 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 more can be given. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid-resistant film. Here, as the cationic polymer, for example, an ionic polymer complex composed of polyethyleneimine, a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is graft-polymerized on an acrylic main skeleton, polyallylamine Or derivatives thereof, aminophenol and the like. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. Examples of the crosslinking agent include a compound 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, and a silane coupling agent. As these crosslinking agents, only one type may be used, or two or more types may be used in combination.

As a method for specifically providing an acid-resistant film, for example, as one example, at least the inner layer side of an aluminum alloy foil (barrier layer) is firstly treated with an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, A degreasing treatment is performed by a known treatment method such as an electrolytic acid washing method and an acid activation method, and then, Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, Treatment liquid (aqueous solution) mainly containing a metal phosphate such as Zn (zinc) phosphate and a mixture of these metal salts, or a non-metal phosphate and a mixture of these non-metal salts are mainly used. A treatment liquid (aqueous solution) as a component or a treatment liquid (aqueous solution) composed of a mixture of these with an aqueous synthetic resin such as an acrylic resin, a phenolic resin, or a urethane resin is roll-coated, gravure printing By coating in a known coating method of the immersion method, it is possible to form the acid-resistant coating. For example, when treated with a Cr (chromium) phosphate-based treatment solution, CrPO ₄ (chromium phosphate), AlPO ₄ (aluminum phosphate), Al ₂ O ₃ (aluminum oxide), Al (OH) _x (water It becomes an acid-resistant film made of aluminum oxide), AlF _x (aluminum fluoride), etc., and when treated with a Zn (zinc) phosphate-based 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 a specific method of providing an acid-resistant film, for example, at least the inner layer side of an aluminum alloy foil is firstly treated with an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and an acid cleaning method. By performing a degreasing treatment by a known treatment method such as an activation method and then performing a known anodic oxidation treatment on the degreasing treatment 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, phosphate) or a chromium compound (for example, chromic acid) can be given. Examples of the phosphate type include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate, and examples of the chromate type include chromium chromate.

  Another example of the acid-resistant film is forming an acid-resistant film such as a phosphorus compound (such as a phosphate), a chromium compound (such as a chromate), a fluoride, and a triazine thiol compound, so that the embossing molding is performed. Prevention of delamination between aluminum and base material layer, dissolution and corrosion of aluminum surface due to hydrogen fluoride generated by reaction between electrolyte and moisture, especially dissolution and corrosion of aluminum oxide present on aluminum surface To improve the adhesiveness (wetting property) of the aluminum surface, prevent delamination between the base layer and aluminum during heat sealing, and depress the base layer and aluminum during press molding in the emboss type. This shows the effect of preventing lamination. Among the substances forming an acid-resistant film, an aqueous solution composed of a phenolic resin, a chromium fluoride (3) compound, and phosphoric acid is applied to the aluminum surface, and drying and baking are favorable.

  Further, the acid-resistant film includes a layer having cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent for crosslinking the anionic polymer, wherein the phosphoric acid or phosphate is You may mix | blend 1-100 mass parts with respect to 100 mass parts of cerium oxides. It is preferable that the acid-resistant film has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent for crosslinking the cationic polymer.

  Further, it is preferable that the anionic polymer is poly (meth) acrylic acid or a salt thereof, or a copolymer containing (meth) acrylic acid or a salt thereof as a main component. Further, it is preferable that the crosslinking agent is at least one selected from the group consisting of a compound having any functional group 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.

  The chemical conversion treatment may be performed by only one type of chemical conversion process, or may be performed by combining two or more types of chemical conversion processes. Furthermore, these chemical conversion treatments may be performed using one kind of compound alone, or may be performed using two or more kinds of compounds in combination. Among the chemical conversion treatments, a chromate treatment, a chromate treatment using a combination of a chromate compound, a phosphoric acid compound, and an aminated phenol polymer are preferable.

  Specific examples of the acid-resistant film include those containing at least one of phosphate, chromate, fluoride, and triazinethiol. Further, an acid resistant film containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

  Specific examples of the acid-resistant coating include a phosphate coating, a chromate coating, a fluoride coating, and a triazine thiol compound coating. As the acid-resistant film, one of these may be used, or a combination of a plurality of types may be used. Furthermore, as the acid-resistant coating, after the chemical conversion treatment surface of the barrier layer is degreased, a treatment solution consisting of a mixture of a metal phosphate and an aqueous synthetic resin, or a mixture of a non-metal phosphate and an aqueous synthetic resin is used. It may be formed of a processing liquid.

The analysis of the composition of the acid-resistant film can be performed by using, for example, time-of-flight secondary ion mass spectrometry. The time-of-flight secondary ion mass spectrometry analysis of the composition of the acid-resistant coating using, for example, secondary ion consisting Ce and P and O ^{_{(e.g., Ce 2 PO 4 +, CePO}} 4 - at least one such ) and, for example, secondary ion of Cr and P and O (e.g., CrPO ₂ ^+, CrPO ₄ ^- peak derived from at least one), such as is detected.

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. For example, in the case of performing the above-mentioned chromate treatment, the chromic acid compound per 1 m ² of the surface of the barrier layer 3 About 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of chromium, about 0.5 to 50 mg, preferably about 1.0 to 40 mg of a phosphorus compound in terms of phosphorus, and 1. It is desirable that it is contained at a ratio of about 0 to 200 mg, preferably about 5.0 to 150 mg.

  The thickness of the acid-resistant film is not particularly limited, but is preferably about 1 nm to 20 μm, more preferably about 1 to 100 nm, from the viewpoint of the cohesive force of the film and the adhesion to the barrier layer and the heat-fusible resin layer. 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.

  In the chemical conversion treatment, after a solution containing a compound used for forming an acid-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method, or the like, the temperature of the barrier layer is reduced to 70%. It is performed by heating to ~ 200 ° C. Before the chemical conversion treatment is performed on the barrier layer, the barrier layer may be subjected to a degreasing treatment by an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like in advance. By performing the degreasing treatment in this manner, it is possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer.

[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 necessary to firmly adhere the barrier layer 3 and the heat-fusible resin layer 4.

The bonding layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, the same adhesive as the adhesive exemplified in the adhesive layer 2 can be used for the adhesive mechanism, the type of the adhesive component, and the like. Further, as the resin used for forming the adhesive layer 5, polyolefin-based 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 constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy or 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.

  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 obtained by modifying a polyolefin by block polymerization or graft polymerization with an acid component such as carboxylic acid. Examples of the acid component used for the modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, and anhydrides thereof. Examples of the polyolefin to be modified include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylenes. Polypropylene such as a random copolymer (for example, a random copolymer of propylene and ethylene); and a terpolymer of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferred.

  In the adhesive layer 5, among the acid-modified polyolefins, a maleic anhydride-modified polyolefin, and particularly a maleic anhydride-modified polypropylene, are preferable.

  Further, from the viewpoint of reducing the thickness of the battery packaging material and obtaining a battery packaging material having excellent shape stability after molding, the adhesive layer 5 is formed by curing a resin composition containing an acid-modified polyolefin and a curing agent. It is more preferable that it is a substance. Preferred examples of the acid-modified polyolefin include those described 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. Preferably, the cured product 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 and a compound having an epoxy group. Further, the adhesive layer 5 preferably includes at least one selected from the group consisting of a urethane resin, an ester resin, and an epoxy resin, and more preferably includes a urethane resin and an epoxy resin. As the ester resin, for example, an amide ester resin is preferable. The amide ester resin is generally formed by a reaction between 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 the case where an unreacted product of a compound having an isocyanate group, a compound having an oxazoline group, and a curing agent such as an epoxy resin remains in the adhesive layer 5, the presence of the unreacted product 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 improving 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 heterocyclic ring, a C = N bond, It is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of C—O—C bonds. Examples of the curing agent having a heterocyclic ring 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. 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 the resin composition containing these curing agents may be determined, for example, by gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF) SIMS) and X-ray photoelectron spectroscopy (XPS).

  The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively improving the adhesion between the acid-resistant film and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate-based curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), And a mixture thereof, a copolymer with another polymer, and the like.

  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 more preferably 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferably, it is within 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 Epocross 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 more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesion between the barrier layer 3 (or the acid-resistant film) and the adhesive layer 5 can be effectively increased.

  The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by an epoxy group present 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 2,000, more preferably about 100 to 1,000, 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) under the condition using polystyrene 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, novolak glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether. One type of epoxy resin may be used alone, or two or more types may be used in combination.

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

  In the present invention, the adhesive layer 5 is 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-based curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N = C = N-). As the carbodiimide-based curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

  From the viewpoint of enhancing the adhesion between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more 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 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), and contains the polyfunctional isocyanate compound (B) in a range in which the amount of the isocyanate group is 0.3 to 10 mol with respect to 1 mol of the carboxyl group, and 1 mol of the carboxyl group. And those formed from the adhesive composition containing the tertiary amine (C) in a range of 1 to 10 mol. The adhesive contains a styrene-based thermoplastic elastomer (A), a tackifier (B), and a polyisocyanate (C), and includes a styrene-based thermoplastic elastomer (A) and a tackifier ( B) and 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 of the styrene-based thermoplastic elastomer (A). Has an active hydrogen derived from an amino group or a hydroxyl group of 0.003 to 0.04 mmol / g, 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 is 0 to 15 mol, and the polyisocyanate (C) is derived from the active hydrogen derived from the styrene-based thermoplastic elastomer (A) and the active hydrogen derived from the tackifier (B). The total 1 mol of an active hydrogen, an isocyanate group also such as those formed by the adhesive composition consisting of those that are included within an amount of 3-150 mol.

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. When the adhesive exemplified in the adhesive layer 2 is used, the thickness 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, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and still more preferably about 0.5 to 5 μm. In the case of an adhesive layer formed from 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.

[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 when assembling the battery.

The resin component used in the heat-fusible resin layer 4 is not particularly limited as long as it is heat-fusible, and examples thereof include polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin. Can be 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 or 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, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylene. Polypropylene (e.g., a random copolymer of propylene and ethylene); and a terpolymer of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferred.

  The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin as 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 that is a constituent monomer of the cyclic polyolefin include a cyclic alkene such as norbornene; specifically, a cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, a cyclic alkene is preferable, and norbornene is more preferable.

  The carboxylic acid-modified polyolefin is a polymer obtained by modifying the polyolefin by block polymerization or graft polymerization with a carboxylic acid. Examples of the carboxylic acid used for the 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 the monomer constituting the cyclic polyolefin with α, β-unsaturated carboxylic acid or an anhydride thereof, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block polymerization or graft polymerization of an unsaturated carboxylic acid or its anhydride. The carboxylic acid-modified cyclic polyolefin is the same as described above. The carboxylic acid used for the modification is the same as that used for the modification of the acid-modified cycloolefin copolymer.

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

  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, or may be formed of two or more layers of the same or different resin components.

  Further, a lubricant may be present on the surface of the heat-fusible resin layer 4 as 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-based 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 amide, palmitic amide, stearic amide, behenic amide, and hydroxystearic amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitamide, N-stearyl stearamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, and the like. Specific examples of methylolamide include methylol stearamide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearin Acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N, N'-distearyladipamide, N, N'-distearylsebacic amide and the like. Specific examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipamide, N, N'-dioleyl sebacic acid amide And the like. Specific examples of the fatty acid ester amide include stearoamidoethyl stearate. Specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, and N, N'-distearylisophthalic acid amide. One type of lubricant may be used alone, or two or more types may be used in combination.

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

  The heat-fusible resin layer 4 may contain a lubricant. In addition, the lubricant present on the surface of the heat-fusible resin layer 4 may be formed by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4, or may be formed by leaching the heat-fusible resin layer. The surface of No. 4 may be coated with a lubricant.

  The thickness of the heat-fusible resin layer 4 is not particularly limited as long as it functions as a heat-fusible resin layer, but is, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm. Is mentioned. When the thickness of the adhesive layer 5 is 10 μm or more, for example, the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, and 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 layer 1 (the barrier layer of the base layer 1) may be used for the purpose of improving design, electrolytic solution resistance, scratch resistance, moldability, and the like. (The side opposite to 3) may be provided with a surface coating layer 6 if necessary. When the surface coating layer 6 is provided, the surface coating layer 6 becomes 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. Among these, the surface coating layer 6 is preferably formed of a two-component curable resin. Examples of the two-component curable resin forming the surface coating layer 6 include a two-component curable urethane resin, a two-component curable polyester, and a two-component curable epoxy resin. Further, an additive may be blended in 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 sphere, a fiber, a plate, an irregular shape, and a balloon. As an additive, specifically, talc, silica, graphite, kaolin, montmorilloid, 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 Nylon, crosslinked acryl, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like can be mentioned. 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. In addition, various surface treatments such as an insulation treatment and a high dispersibility treatment may be applied to the surface of the additive.

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

  The method of forming the surface coating layer 6 is not particularly limited, and includes, for example, a method of applying a two-component curable resin forming the surface coating layer to the outer surface of the base material layer 1. In the case of adding an additive, 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 function as the surface coating layer 6 is exhibited, and 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 in which each layer having a predetermined composition is laminated can be obtained. A layer, a barrier layer, and a heat-fusible resin layer, which are stacked in this order to obtain a laminate, and a thermomechanical analysis for measuring a displacement of a probe is performed. The probe is placed on the surface of the adhesive layer in a cross section, and the set value of the deflection of the probe at the start of the measurement is -4 V, and the probe is heated from 40 ° C. to 350 ° C. at a temperature rising rate of 5 ° C./min. A method for producing a packaging material for a battery, wherein the temperature at which the displacement of the probe is maximized when heated is 190 ° C. or more and 320 ° C. or less. In the method for producing a battery packaging material of the present invention, the details of the base layer 1, the adhesive layer 2, the barrier layer 3, and the heat-fusible resin layer 4 are as described above. If necessary, the above-mentioned adhesive layer 5 and surface coating layer 6 may be provided.

  An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminate in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are sequentially laminated (hereinafter, sometimes referred to as “laminate A”) is formed. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 2 to the base layer 1 or the barrier layer 3 by a coating method such as a gravure coating method or a roll coating method. After drying, the barrier layer 3 or the base material layer 1 may be laminated and the adhesive layer 2 may be cured by a dry lamination method. At this time, when laminating the barrier layer 3, at least one surface of the barrier layer 3 may be formed with the above-mentioned acid-resistant film formed in advance.

  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 resin component constituting the adhesive layer 5 is formed on the barrier layer 3 of the laminate A by a method such as a gravure coating method, a roll coating method, and an extrusion laminating method. What is necessary is just to apply. The method of providing the adhesive layer 5 between the barrier layer 3 and the heat-fusible resin layer 4 includes, for example, (1) bonding the adhesive layer 5 and the heat-fusible resin layer on the barrier layer 3 of the laminate A. (Coextrusion laminating method), (2) separately forming a laminate in which an adhesive layer 5 and a heat-fusible resin layer 4 are laminated, and forming the laminate into a barrier layer of the laminate A. (3) a method of extruding or solution coating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate A, drying at a high temperature, and baking, etc. A method of laminating a heat-fusible resin layer 4 previously formed into a sheet on the adhesive layer 5 by a thermal laminating method, and (4) a method of forming a sheet in advance with the barrier layer 3 of the laminate A. Melted between the film and the heat-fusible resin layer 4 While pouring adhesive layer 5, and a method of bonding a laminate A and the heat-welding resin layer 4 through the adhesive layer 5 (sandwich lamination method).

  When the surface coating layer 6 is provided, the surface coating layer is laminated on the surface of the substrate layer 1 opposite to the barrier layer 3. The surface coating layer can be formed, for example, by applying the above-described 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 substrate layer 1 and the step of laminating the surface coating layer 6 on the surface of the substrate layer 1 are 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 / substrate layer 1 / adhesive layer 2 / barrier layer 3 provided with an acid-resistant coating on at least one surface as required / optionally provided A laminate composed of the adhesive layer 5 and the heat-fusible resin layer 4 is formed. In order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed, a heat roll is further provided. It may be subjected to a heat treatment of a contact type, a hot air type, a near or far infrared type, or the like.

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

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

  Specifically, at least a positive electrode, a negative electrode, and a battery element provided with an electrolyte, 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 protrude outward, A battery is formed by forming a flange (a region where the heat-fusible resin layers are in contact with each other) around the periphery of the element so as to be formed, and heat-sealing the heat-fusible resin layers of the flange to seal them. There is provided a battery using the packaging material. When the battery element is accommodated in the 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 located inside (the surface in contact with the battery element). To form a package.

  The battery packaging material of the present invention may be used for any of a primary battery and 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. Examples include an iron storage battery, a nickel-zinc storage battery, a silver oxide-zinc storage battery, a metal-air battery, a polyvalent cation battery, a capacitor, and a capacitor. Among these secondary batteries, suitable applications of the battery packaging material of the present invention include lithium ion batteries and lithium ion polymer batteries.

  Since automobiles and mobile devices are sometimes used in harsh environments such as a wet heat environment, 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 moist heat environment. For this reason, the battery packaging material of the present invention is particularly useful, for example, as a packaging material used for vehicle batteries and mobile device batteries.

  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.

<Manufacture of battery packaging materials>
A packaging material for a battery was manufactured so as to have a layered configuration 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 main component containing a polyester polyol composed of a polybasic acid component and a polyhydric alcohol component, and polyfunctional. ALM is an aluminum alloy foil, and PPa is an acid-modified polypropylene resin (an unsaturated carboxylic acid graft graft-modified with an unsaturated carboxylic acid). Modified PP) and PP is a polypropylene (random copolymer). Further, in Table 1, the numerical value described for each layer means the thickness (μm) of the layer. For example, “ON25” means “a biaxially stretched nylon film having a thickness of 25 μm”. .

  Table 1 shows the content ratio of the isomers of the aromatic polybasic acid component (isophthalic acid: terephthalic acid) 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 and 2>
In Examples 1 to 6 and Comparative Examples 1 and 2, a biaxially stretched nylon film was used as the resin film constituting the base material layer. One side of the biaxially stretched nylon film is subjected to corona treatment. In Examples 1 to 6 and Comparative Examples 1 and 2, erucamide was applied as a lubricant to the surface of the biaxially stretched nylon film that had not been 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) composed of the regioisomeric content shown in Table 1 were formed on the surface of the biaxially stretched nylon film on which corona treatment was performed. )) And a curing agent containing a polyfunctional isocyanate component (15 parts by mass) and a curing agent containing a polyfunctional isocyanate component (15 parts by mass). It applied so that it might become. Next, by laminating the aluminum alloy foil on the adhesive layer side of the base material layer and the chemical conversion treated surface of the aluminum alloy foil, bonding them under pressure and heat, and then performing aging treatment, the base material layer / A laminate in which an adhesive layer / aluminum alloy foil was sequentially laminated was produced. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method using a treatment solution comprising a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium was 10 mg / m ² (dry mass). This 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 and 4, a polybasic acid component (60 parts by mass) in which a biaxially stretched polyethylene terephthalate film and a biaxially stretched nylon film were configured at the content ratio of regioisomers shown in Table 1 ) And a polyhydric alcohol component (40 parts by mass) and a two-component urethane adhesive comprising a main component (100 parts by mass) containing a polyester polyol and a curing agent containing a polyfunctional isocyanate component (15 parts by mass). The laminated film thus obtained was used as a substrate layer. One surface of the biaxially stretched polyethylene terephthalate film and both surfaces of the biaxially stretched nylon film were subjected to corona treatment, 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, erucamide was applied as a lubricant to the surface of the biaxially stretched polyethylene terephthalate film that had not been subjected to corona treatment (application amount: 10 mg / m ² ). Polyester polyol comprising a polybasic acid component (60 parts by mass) and a polyhydric alcohol component (40 parts by mass) composed of the regioisomeric content 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 comprising a main agent (100 parts by mass) containing a and a curing agent (15 parts by mass) containing a polyfunctional isocyanate component was applied so that the thickness after curing became 3 μm. Next, by laminating the aluminum alloy foil on the adhesive layer side of the base material layer and the chemical conversion treated surface of the aluminum alloy foil, bonding them under pressure and heat, and then performing aging treatment, the base material layer / A laminate in which an adhesive layer / aluminum alloy foil was sequentially laminated was produced. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method using a treatment solution comprising a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium was 10 mg / m ² (dry mass). This 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 constituting the base layer. One side of the PET film is subjected to a corona treatment. 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) constituted on the corona-treated surface of the PET film at the regioisomer content ratio shown in Table 1. (100 parts by mass) and a curing agent (15 parts by mass) containing a polyfunctional isocyanate component, an adhesive layer made of a two-component urethane adhesive was applied so that the thickness after curing became 3 μm. In Examples 13 to 18 and Comparative Examples 5 and 6, erucamide was applied as a lubricant to the surface of the biaxially stretched polyethylene terephthalate film that had not been subjected to corona treatment (application amount: 10 mg / m ² ). Next, an aluminum alloy foil is prepared, and the adhesive layer side of the base material layer and the chemical conversion treated surface of the aluminum alloy foil are laminated, and after pressure and heat bonding, an aging treatment is performed. A laminate in which a layer / adhesive layer / aluminum alloy foil was laminated in this order was produced. The chemical conversion treatment of the aluminum alloy foil was performed by a roll coating method using a treatment solution comprising a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium was 10 mg / m ² (dry mass). This 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 an unsaturated carboxylic acid) constituting an adhesive layer was separately heat-fusible. By co-extruding a polypropylene (random copolymer) constituting the resin layer, a two-layer co-extruded film including 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 two-layer co-extruded film prepared above was superimposed on the aluminum alloy foil side of the laminate composed of the base material layer / adhesive layer / aluminum alloy foil so that the aluminum alloy foil was in contact with the aluminum alloy foil. By heating, a laminate was obtained in which a substrate layer / adhesive layer / aluminum alloy foil / adhesive layer / heat-fusible resin layer was sequentially laminated. The obtained laminate was once cooled, and then subjected to a heat treatment to obtain a packaging material for each battery. Erucamide as a lubricant was applied to the surface of the heat-fusible resin layer (application amount: 10 mg / m ² ).

<Measurement of mass ratio between isophthalic acid and terephthalic acid>
The mass ratio of isophthalic acid and its derivative to terephthalic acid and its derivative in the adhesive layer was measured by the following measurement method using a gas chromatograph mass spectrometer. First, the adhesive constituting the adhesive layer was derivatized using a methylating agent as a pretreatment. 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 Corporation), analysis was performed under measurement conditions under which the retention time of isophthalic acid and terephthalic acid can be separated.
[Derivatization procedure]
As a methylating agent, a 25% methanol solution of tetramethylammonium hydroxide (TMAH) was prepared. About 5 mg of the sample and about 3 μl of the methylating agent were sealed in a glass tube. Next, the glass tube was melted with a gas burner and plugged. Next, heating was performed at 200 to 300 ° C. for about 15 minutes in an electric furnace. During heating, derivatization proceeds. Next, the glass tube was opened and the sample was taken out.
[Measurement condition]
Column: UA-5 manufactured by FRONTIER LAB (stationary phase 5% diphenyl-95% dimethylpolysiloxane), inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm
Oven temperature: Hold at 50 ° C. for 5 minutes and raise the temperature to 320 ° C. at 10 ° C./min. Ionization method: Electron impact ionization method (EI method)
Detector: Quadrupole detector Pyrolysis 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. The retention time (retention time) under these measurement conditions is phthalic acid, terephthalic acid, and isophthalic acid. It becomes the order of.

<Measurement of softening point of adhesive layer>
A probe is placed on the surface of the adhesive layer in the cross section of each battery packaging material (the tip radius of the probe is 30 nm or less, the deflection value of the probe is -4 V), and the probe is heated from 40 ° C. to 350 ° C. The temperature was increased at a rate of 5 ° C./min), and the displacement of the probe was measured. Details of the measurement conditions are as follows. AFM plus system manufactured by ANASYS INSTRUMENTS was used as an atomic force microscope equipped with a nanothermal microscope composed of a cantilever with a heating mechanism, and a probe used as a probe was ANALevel INSTRUMENTS's cantilever ThermaLevel AN2-200 (spring constant 0.1 to 1). 0.5 N / m). The measurement position was changed and the average value obtained by N = 3 measurements was used. The temperature at which the displacement becomes the maximum is defined as the softening point of the adhesive layer, and the measurement results are shown in Table 1. For the calibration, three attached samples (polycaprolactam (melting point 55 ° C.), polyethylene (melting point 116 ° C.), polyethylene terephthalate (melting point 235 ° C.)) were applied at an applied voltage of 0.1 to 10 V and a speed of 0.2 V / The setting value of seconds and deflection was set to -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 as described above was cut to prepare strips of 150 mm (TD: Transverse Direction) × 90 mm (MD: Machine Direction), which were used as test samples. 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. The TD is the direction perpendicular to the same plane as the MD and the RD. The rolling direction of the aluminum alloy foil can be confirmed by rolling marks of the aluminum alloy foil. This sample was placed in a 25 ° C. environment at a temperature of 25 ° C., and a rectangular molding die (female mold, surface: 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) is 3.2 μm as specified in Table 2 of the standard surface roughness standard piece, corner R2.0 mm, ridge R1.0 mm. ) And a corresponding molding die having a rectangular shape in a plan view (male mold, surface is JIS B 0659-1: 2002 Annex 1 (reference), specified in Table 2 of standard surface roughness standard piece for comparison, The maximum height roughness (nominal value of Rz) is 1.6 μm.The corner R2.0 mm and the ridgeline R1.0 mm) are used to reduce the pressing depth (surface pressure) from 0.25 MPa to 0.5 mm from a molding depth of 0.5 mm. Change the molding depth in increments of .5mm, 10 samples each Was cold-forming (draw 1-stage molding) with. At this time, the test sample was placed on the female mold and molded so that the heat-fusible resin layer side was positioned on the male mold side. The clearance between the male and female molds was 0.3 mm. The sample after cold forming was irradiated with light with a penlight in a dark room, and it was confirmed whether or not pinholes or cracks had occurred in the aluminum alloy foil due to light transmission. Amm is the deepest forming depth where pinholes and cracks do not occur in all of the 10 samples of aluminum alloy foil, and the number of samples where pinholes and the like occur at the shallowest forming depth where pinholes and the like occur in the aluminum alloy foil , And the value calculated by the following equation was defined as the critical forming depth of the battery packaging material. Table 1 shows the results.
Limit forming depth = Amm + (0.5mm / 10) × (10-B)

<Durability evaluation in wet heat environment after molding>
Each of the battery packaging materials obtained above was cut to produce strips of 150 mm (TD) × 100 mm (MD), which were used as test samples. In addition, 10 test samples were produced 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. The TD is the direction perpendicular to the same plane as the MD and the RD. The rolling direction of the aluminum alloy foil can be confirmed by rolling marks of the aluminum alloy foil. The mold is a male mold having a rectangular shape in a plan view of 31.6 mm (MD) x 54.5 mm (TD) (surface is JIS B 0659-1: Annex 1 of 2002 (reference) The maximum height roughness (nominal value of Rz) defined in Table 2 is 1.6 μm, the corner R2.0 mm, the ridgeline R1.0 mm) and the female mold (0.5 mm in clearance) from the male mold ( The surface has a maximum height roughness (nominal value of Rz) of 3.2 μm as specified in Table 2 of JIS B 0659-1: 2002 Appendix 1 (Reference) Comparative Surface Roughness Standard Piece. 0.0mm, ridge R1.0mm). 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 a forming depth shown in Table 1 and cold-formed (one-step drawing). Next, the cold-formed sample was placed in a constant-temperature and constant-humidity bath at a temperature of 65 ° C. and a relative humidity of 90% RH, and allowed to stand for 72 hours. Take out the molded sample from the thermo-hygrostat and visually check whether floating (peeling of the base material layer) has occurred between the base material layer and the aluminum alloy foil. Table 1 shows the proportion of the sample that was found.

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

Claims (8)

At least, a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate including in this order,
The adhesive layer is formed of a cured product 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, isophthalic acid and its derivatives and terephthalic acid and its derivatives 35: 65-90: are contained in 10 mass ratio,
In the thermomechanical analysis for measuring the displacement of the probe, the probe is set on the surface of the adhesive layer in the cross section of the laminate, and the set value of the deflection of the probe at the start of the measurement is -4 V, and the temperature rise rate is 5 A packaging material for a battery, wherein a temperature at which the displacement of the probe is maximum when the probe is heated from 40 ° C. to 350 ° C. under a condition of ° C./min is 190 ° C. or more and 320 ° C. or less.   The battery packaging material according to claim 1, wherein the adhesive layer includes a coloring agent.   The battery packaging material according to claim 1, wherein the thickness of the barrier layer is 10 μm or more and 100 μm or less.   The packaging material for a battery according to any one of claims 1 to 3, wherein the barrier layer is made of an aluminum alloy foil.   The battery packaging material according to any one of claims 1 to 4, wherein the base material layer contains at least one of polyester and polyamide.   A battery, wherein a battery element including at least a positive electrode, a negative electrode, and an electrolyte is accommodated in a package formed of the battery packaging material according to claim 1. 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 cured product 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, isophthalic acid and its derivatives and terephthalic acid and its derivatives 35: 65-90: are contained in 10 mass ratio,
In the thermomechanical analysis for measuring the displacement of the probe, the probe is set on the surface of the adhesive layer in the cross section of the laminate, and the set value of the deflection of the probe at the start of the measurement is -4 V, and the temperature rise rate is 5 A method for producing a packaging material for a battery, wherein a temperature at which the displacement of the probe is maximum when the probe is heated from 40 ° C. to 350 ° C. under a condition of ° C./min is 190 ° C. or more and 320 ° C. or less. The battery packaging according to claim 7, wherein the adhesive layer is formed by curing 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. Material manufacturing method.

Images