JP5704199B2 - Battery packaging materials - Google Patents

Description

  The present invention relates to a battery packaging material that can ensure safety even when the pressure or temperature in the battery continuously increases. More specifically, the battery element can be kept sealed until the pressure and temperature in the battery rise to a certain level, and the pressure and temperature in the battery continue to rise continuously. The present invention relates to a battery packaging material that can be opened quickly and gently at the same time to suppress excessive expansion of the packaging material for potential, runaway battery reaction, ignition, and the like.

  Conventionally, various types of batteries have been developed. In any battery, a packaging material is an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used as battery packaging, but in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes. At the same time, there is a demand for reduction in thickness and weight. However, metal battery packaging materials that have been widely used in the past have the disadvantages that it is difficult to follow the diversification of shapes and that 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 reduced in thickness and weight, a film-like laminate in which a base layer / adhesive layer / metal layer / sealant layer are sequentially laminated. Has been proposed (see, for example, Patent Document 1). Such a film-shaped battery packaging material is formed so that the battery element can be sealed by causing the sealant layers to face each other and heat-sealing the peripheral portion by heat sealing.

  On the other hand, depending on the type of electrolyte, the battery may generate a combustible gas and the pressure may increase. For example, when the battery is exposed to a high temperature, the organic solvent used in the electrolytic solution may be decomposed to generate a combustible gas and cause an increase in pressure. In addition, the battery may continuously increase the temperature in the battery due to charging due to overvoltage or discharging with an excessive current, thereby causing a runaway battery reaction.

  In a battery using a film-like battery packaging material, such an increase in the pressure or temperature in the battery may cause the battery packaging material to be cleaved and cause ignition due to ejection of combustible gas. Further, if the pressure or temperature rises continuously in the battery and the battery reaction runs out of control when the battery packaging material is excessively expanded, the battery may explode.

  Conventionally, as a packaging material for a battery that can suppress the tearing of the heat seal part and the break before the heat seal part even when the pressure in the battery rises continuously, the sealant layer or adjacent thereto It has been reported that one of the adhesive resin layers has a cleavage inducing portion in which the stress at the time of cleavage is smaller than the stress at the time of cleavage of the fused surface between the sealant layers (see Patent Document 2). However, Patent Document 2 only suppresses the progress of cleavage at low stress at the interface between the adhesive resin layer and the corrosion prevention treatment layer on the metal layer by inducing cleavage at such a cleavage induction portion. However, it is not designed so that it can be opened gently when the pressure or temperature in the battery has risen continuously. In fact, in Patent Document 2, when a strong stress is applied, delamination in which cleavage proceeds between layers having adhesiveness, or cohesive failure in which cracks progress in an adhesive layer occurs. Designed to be If the battery is opened due to delamination or cohesive failure when the pressure or temperature in the battery rises, there is a concern that the risk of ignition or explosion may increase due to the rapid ejection of combustible gas.

  Therefore, in order to ensure safety when the battery pressure or temperature rises continuously, the battery packaging material is sealed without sealing until reaching a certain temperature. By maintaining the state, it is required to design so as to gradually release the gas in the battery packaging material by gently opening the wrapping material while suppressing ignition and the like due to a sudden ejection of the combustible gas.

JP 2001-202927 A JP 2012-203982 A

  An object of this invention is to provide the battery packaging material which can ensure safety | security even when the raise in the pressure in a battery and temperature progresses continuously. More specifically, the present invention can maintain the battery element in a sealed state until the pressure or temperature in the battery rises to a certain level, and the pressure or temperature in the battery continuously increases. It is an object of the present invention to provide a battery packaging material that can be opened quickly and gently when it reaches an advanced state to suppress excessive expansion of the battery packaging material, runaway battery reaction, ignition, and the like.

  The inventors of the present invention have made extensive studies to solve the above-mentioned problems. As a result, the present invention provides a battery packaging material comprising at least a base material layer, a metal layer, and a sealant layer in this order. When the material is heat-sealed and the battery element is sealed and heated, after peeling occurs at least in part between the metal layer and the outer surface of the sealant layer (the innermost layer side surface) while maintaining the sealed state The battery packaging material that operates so as to shift to the unsealed state can keep the battery element sealed until the pressure and temperature in the battery rise to a certain level, and the pressure and temperature in the battery It has been found that when the rise of the film is in a state of continuously progressing, a minute tear such as a pinhole can be quickly generated in the peeled portion of the sealant layer, leading to a gentle opening. The present invention has been completed by further studies based on such knowledge.

That is, this invention provides the invention of the aspect hung up below.
Item 1. A battery packaging material comprising a laminate having at least a base material layer, a metal layer, and a sealant layer in this order,
When the battery packaging material is heat sealed and the battery element is heated in a sealed state, after peeling occurs in at least a part between the metal layer and the outer surface of the sealant layer while maintaining the sealed state Battery packaging material that operates to transition to an open state.
Item 2. Item 2. The battery packaging material according to Item 1, wherein after the inner bag is formed at the part where the peeling occurs, the inner bag is opened and the inner bag is operated to move to the opened state.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, further comprising an adhesive layer between the base material layer and the metal layer.
Item 4. Item 4. The battery packaging material according to any one of Items 1 to 3, further comprising an adhesive layer between the metal layer and the sealant layer.
Item 5. The peeling includes an interface between the metal layer and the sealant layer, an interface between the metal layer and the adhesive layer, an interface between the adhesive layer and the sealant layer, an inside of the adhesive layer, and an inside of the sealant layer. Item 5. The battery packaging material according to any one of Items 1 to 4, which is produced at least in one place.
Item 6. Item 6. The battery packaging material according to any one of Items 1 to 5, wherein a laminate strength between the metal layer and the sealant layer at 25 ° C. is 3 (N / 15 mm) or more.
Item 7. The laminate strength between the metal layer and the sealant layer at 80 ° C. is 2.5 (N / 15 mm) or more, and the laminate strength between the metal layer and the sealant layer at 125 ° C. is 2. Item 7. The battery packaging material according to any one of Items 1 to 6, which is 5 (N / 15 mm) or less.
Item 8. Item 8. The battery packaging material according to any one of Items 1 to 7, wherein a seal strength of a portion heat-sealed in a state where the sealant layers face each other is 30 (N / 15 mm) or more at 25 ° C.
Item 9. Item 9. The battery packaging material according to any one of Items 1 to 8, wherein a seal strength of a portion heat-sealed in a state where the sealant layers face each other is 20 (N / 15 mm) or less at 125 ° C.
Item 10. In the bag-shaped packaging material obtained by heat-sealing with the sealant layers facing each other, after leaving the electrolyte solution in the internal space of the bag-shaped packaging material for 24 hours at 85 ° C., Item 10. The battery packaging material according to any one of Items 1 to 9, wherein the heat-sealed portion has a sealing strength of 0.2 (N / 15 mm) or more.

  The battery packaging material of the present invention is a battery packaging material comprising a laminate having at least a base material layer, a metal layer, and a sealant layer in this order, and the battery packaging material is heat sealed to seal the battery element. When the temperature is raised in such a state, it operates so as to shift to the opened state after peeling occurs at least at a part between the metal layer and the outer surface of the sealant layer while keeping the sealed state. By adopting such a specific configuration, the battery packaging material of the present invention can keep the battery element sealed until the pressure or temperature in the battery rises to a certain level, and the battery When the pressure or temperature rises in a continuous state, the sealant layer in the peeled portion can be rapidly opened to cause fine cleaving such as pinholes to be opened gently. More specifically, the internal pressure can be gently lowered by releasing the combustible gas generated inside the battery to the outside after the pressure and temperature inside the battery reach a certain level. By reducing the internal pressure inside the battery, it is possible to suppress the release of the electrolytic solution and the battery cell to the outside. Furthermore, when air flows into the battery as the gas is released, the concentration of the combustible gas generated inside the battery is reduced, and the ignition of the battery can be suppressed. Further, the ignition of the battery can be suppressed also by the fact that the electrolyte in the battery is easily dried by the inflow of air. In particular, when the battery reaches a high temperature, the separator inside the battery is likely to shrink, so the battery is deformed with an increase in internal pressure, and there is an increased risk of ignition due to a short circuit, but by using the battery packaging material of the present invention, Since the concentration of the flammable gas that causes ignition can be reduced by the release of the flammable gas generated inside the battery and the inflow of air from the outside, ignition due to a short circuit can be effectively suppressed. As described above, according to the battery packaging material of the present invention, the battery packaging material can be gently opened even when the pressure or temperature in the battery continues to rise continuously. Excessive expansion and ignition of the packaging material can be suppressed, ensuring safety.

It is a schematic sectional drawing of the packaging material for batteries of this invention. It is a schematic sectional drawing of the packaging material for batteries of this invention. One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). One side surface of a state (A) in which two battery packaging materials of the present invention are heat-sealed to form a sealed space (A), a state in which peeling is formed after the temperature rise (B), and a state at the time of opening (C) Is a schematic cross-sectional view (the left end is heat-sealed, and the right-hand side is omitted). Two conventional battery packaging materials are heat-sealed to form a sealed space, and a schematic cross-sectional view of one side showing the state of tearing that occurs when heated (the left end is heat-sealed, the right-hand side is omitted) ).

  The battery packaging material of the present invention is a battery packaging material comprising a laminate having at least a base material layer, a metal layer, and a sealant layer in this order, and the battery packaging material is heat sealed to seal the battery element. When the temperature is raised in such a state, it operates so as to shift to the opened state after peeling occurs at least at a part between the metal layer and the outer surface of the sealant layer while keeping the sealed state. Hereinafter, the battery packaging material of the present invention will be described in detail.

1. Laminated structure of battery packaging material The battery packaging material of the present invention comprises a laminate having at least a base material layer 1, a metal layer 3, and a sealant layer 4 in this order. When the battery packaging material of the present invention is used in a battery, the base material layer 1 is the outermost layer and the sealant layer 4 is the innermost layer (battery element side). When assembling the battery, the sealant layers 4 located on the periphery of the battery element are brought into contact with each other and thermally welded to seal the battery element and seal the battery element. As shown in FIG. 1, the battery packaging material of the present invention may have an adhesive layer 2 between a base material layer 1 and a metal layer 3. As shown in FIG. 2, the battery packaging material of the present invention may have an adhesive layer 5 between the metal layer 3 and the sealant layer 4.

2. Opening mechanism of battery packaging material The battery packaging material of the present invention is a battery element until the pressure or temperature in the battery rises to a certain level (for example, the temperature in the battery is about 100 to 160 ° C.). When the pressure and temperature rise in the battery is continuously advanced, the outer surface (the innermost layer side surface) of the metal layer 3 and the sealant layer 4 is maintained. A portion of the sealant layer 4 that is peeled between the layers is provided with a gentle opening property that quickly causes fine cleavage such as pinholes. The example of the opening mechanism of the packaging material for batteries of this invention is demonstrated using FIGS. 3 and 4, the case where the battery packaging material of the present invention has the adhesive layer 2 is described, and FIGS. 5 to 8 are cases where the adhesive layer 5 is further provided. . 3 to 8 show schematic cross-sectional views of one side surface when a battery element is sealed in two battery packaging materials of the present invention. In A of FIGS. 3 to 8, the edges of the two sealant layers 4 of the battery packaging material are heat-sealed to form a sealed space. Although the battery element is accommodated in the sealed space, the battery element is omitted in FIGS. 3A, (A-1) shows a cross-sectional view when two battery packaging materials are molded together, and (A-2) shows only one battery packaging material. Sectional drawing at the time of shape | molding is shown. Although not shown, in the present invention, the two battery packaging materials may not be molded together. In the present invention, the two battery packaging materials may have different laminated structures. For example, one battery packaging material has the adhesive layer 2 shown in FIGS. 3 and 4. Instead, the other battery packaging material may have the adhesive layer 2 and the adhesive layer 5 shown in FIGS. Furthermore, in the present invention, the sealant layers 4 of one battery packaging material may be heat-sealed to form a sealed space, or the sealant layers 4 of a plurality of battery packaging materials may be heat-sealed. An enclosed space may be formed. The battery packaging material of the present invention has a sealing property until it reaches a certain level (for example, the temperature in the battery is about 100 to 160 ° C.) by at least one of the opening mechanisms shown in FIGS. It has a quick and gentle opening after that. Hereinafter, in FIG. 3 to FIG. 8, the opening mechanism of the battery packaging material of the present invention will be described using a cross-sectional view in which two battery packaging materials are molded. When it is molded and when both are not molded, it is opened by the same mechanism.

  First, in the unsealing mechanism shown in FIG. 3, when the temperature is raised from the state of FIG. 3A to a certain temperature, at least one of the interfaces between the metal layer 3 and the sealant layer 4 as shown in FIG. 3B. Part peels (interfacial peeling). At this time, it is preferable that the peeled portion of the sealant layer 4 is formed in a bag shape (inner bag) to keep the battery element sealed. Subsequently, the state rapidly shifts to the state shown in FIG. 3C, and a minute tear such as a pinhole (indicated by reference numeral 10 in FIG. 3) is formed in the region (preferably the inner bag) of the sealant layer 4 peeled from the metal layer 3. ) Will occur and will be opened under mild conditions.

  Further, in the unsealing mechanism shown in FIG. 4, when the temperature is raised from the state of A in FIG. 4 to a certain temperature, cohesive separation occurs inside the sealant layer 4 as shown in B of FIG. At this time, it is preferable that the coherent and peeled portion of the sealant layer 4 is formed in a bag shape (inner bag) to keep the battery element sealed. Subsequently, the state quickly shifts to the state shown in FIG. 4C, and a minute tear (indicated by reference numeral 10 in FIG. 4) such as a pinhole occurs in the cohesive peeled region (preferably the inner bag) of the sealant layer 4. Open under mild conditions.

  Further, in the unsealing mechanism shown in FIG. 5, when the temperature is raised from the state of FIG. 5A to a certain temperature, at least the interface between the metal layer 3 and the adhesive layer 5 is shown in FIG. 5B. Peel partly (interfacial peeling). At this time, preferably, the adhesive layer 5 and the sealant layer 4 are formed in a bag shape (inner bag) to keep the battery element sealed. Subsequently, the state rapidly shifts to the state shown in FIG. 5C, and fine cracks such as pinholes (in the inner bag) of the adhesive layer 5 and the sealant layer 4 separated from the metal layer 3 (preferably the inner bag) (in FIG. 5). (Denoted by reference numeral 10) occurs, and the package is opened under mild conditions.

  Further, in the unsealing mechanism shown in FIG. 6, when the temperature is raised from the state of A in FIG. 6 to a certain temperature, cohesive peeling occurs inside the adhesive layer 5 as shown in B of FIG. At this time, preferably, the cohesive peeled portion of the adhesive layer 5 and the sealant layer 4 in contact therewith are formed into a bag shape (inner bag) to keep the battery element sealed. Subsequently, the state rapidly shifts to the state shown in FIG. 6C, and a minute tear such as a pinhole (in FIG. (Denoted by reference numeral 10) occurs, and the package is opened under mild conditions.

  Further, in the unsealing mechanism shown in FIG. 7, when the temperature is raised from the state of A of FIG. 7 to a certain temperature, at least the interface between the adhesive layer 5 and the sealant layer 4 is shown in FIG. Peel partly (interfacial peeling). At this time, the sealant layer 4 is preferably in a bag shape (inner bag) and the battery element is kept sealed. Subsequently, the state rapidly shifts to the state shown in FIG. 7C, and a fine tear such as a pinhole (indicated by reference numeral 10 in FIG. 7) is formed in the region (preferably the inner bag) of the sealant layer 4 peeled from the adhesive layer 5. ) Will occur and will be opened under mild conditions.

  Further, in the unsealing mechanism shown in FIG. 8, when the temperature is raised from the state of A in FIG. 8 to a certain temperature, cohesive peeling occurs inside the sealant layer 4 as shown in B of FIG. At this time, it is preferable that the region where the sealant layer 4 is agglomerated and peeled is formed in a bag shape (inner bag) to keep the battery element sealed. Subsequently, the state rapidly shifts to the state shown in FIG. 8C, and a minute tear (indicated by reference numeral 10 in FIG. 8) such as a pinhole occurs in the cohesive peeled region (preferably the inner bag) of the sealant layer 4. Open under mild conditions.

  Although not illustrated, as described later, when the adhesive layer 5 or the sealant layer 4 is formed of a plurality of layers, when peeling occurs inside the adhesive layer 5 or the sealant layer 4, the plurality of layers In at least a part of the interface, peeling occurs, and a fine cleavage such as a pinhole or the like occurs in the peeled area, which may result in an opened state under mild conditions.

  As described above, in the battery packaging material of the present invention, when the temperature is increased to a certain temperature (for example, a temperature in the range of 100 to 160 ° C.), the outer surface of the metal layer and the sealant layer (the innermost layer side surface) At least a part (at least a part of the interface of each layer or at least a part inside each layer) peels off, but the battery element can be kept sealed by the sealant layer, and then the peeled part of the sealant layer In addition, it can be opened gently by causing a fine tear such as a pinhole in the affiliation. The opened state may be a combination of two or more of FIGS.

  On the other hand, conventional battery packaging materials ignite or explode without being opened quickly, or when the temperature reaches a certain temperature, the sealed state rapidly changes to the opened state, causing a swift jet of combustible gas or electrolyte. There is a case. Here, FIG. 9A shows an example of a state of interfacial delamination in which cleavage progresses rapidly at the heat seal interface between the sealant layers in the conventional battery packaging material. Moreover, in the conventional battery packaging material, an example of the state of cohesive separation in which the cleavage proceeds rapidly in the vicinity of the heat seal interface of the sealant layer is shown in FIG. 9B. FIG. 9C shows an example of a state of delamination in which cracking proceeds between layers (interlayers in the sealant layer) after the sealant layer is broken in a conventional battery packaging material. The “root break” means that the sealant layer is broken at the inner edge of the heat seal portion. In the battery packaging material of the present invention, since the conventional interfacial peeling, cohesive peeling, or delamination does not occur and a sudden opening state is not caused, the pressure in the battery is higher than that of the conventional battery packaging material. Excellent safety when temperature and temperature rise continuously.

3. Composition of each layer forming base material for battery [base material layer 1]
In the battery packaging material of the present invention, the base material layer 1 is a layer forming the outermost layer. The material for forming the base material layer 1 is not particularly limited as long as it has insulating properties. Examples of the material for forming the base material layer 1 include polyester, polyamide, epoxy, acrylic, fluororesin, polyurethane, silicon resin, phenol, polyetherimide, polyimide, and a mixture or copolymer thereof.

  Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolymerized polyester mainly composed of ethylene terephthalate, butylene terephthalate as a repeating unit. Examples thereof include a copolymer polyester mainly used. The copolymer polyester mainly composed of ethylene terephthalate is a copolymer polyester that polymerizes with ethylene isophthalate mainly composed of ethylene terephthalate (hereinafter, polyethylene (terephthalate / isophthalate)). Abbreviated), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). In addition, as a copolymer polyester mainly composed of butylene terephthalate as a repeating unit, specifically, a copolymer polyester that polymerizes with butylene isophthalate having butylene terephthalate as a repeating unit (hereinafter referred to as polybutylene (terephthalate / isophthalate)). For example), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyesters may be used individually by 1 type, and may be used in combination of 2 or more type. Polyester has the advantage of being excellent in electrolytic solution resistance and less likely to cause whitening due to the adhesion of the electrolytic solution, and is suitably used as a material for forming the base material layer 1.

  Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 6,6; terephthalic acid and / or Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) and the like, which include a structural unit derived from isophthalic acid, Aromatic polyamides such as silylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and lactam components and isocyanate components such as 4,4′-diphenylmethane-diisocyanate. Polymerized polyamide, co-weight Polyester amide copolymer and polyether ester amide copolymer is a copolymer of polyamide and polyester and polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used individually by 1 type, and may be used in combination of 2 or more type. The stretched polyamide film is excellent in stretchability, can prevent whitening due to resin cracking of the base material layer 1 during molding, and is suitably used as a material for forming the base material layer 1.

  The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, in particular, a biaxially stretched resin film has improved heat resistance by orientation crystallization, and thus is suitably used as the base material layer 1. Moreover, the base material layer 1 may be formed by coating the above-mentioned raw material on the metal layer 3.

  Among these, as a resin film which forms the base material layer 1, Preferably nylon and polyester, More preferably, biaxially stretched nylon, biaxially stretched polyester, Most preferably, biaxially stretched nylon is mentioned.

  The base material layer 1 can also be laminated with at least one of resin films and coatings of different materials in order to improve pinhole resistance and insulation when used as a battery package. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, and a multilayer structure in which a biaxially stretched polyester and a biaxially stretched nylon are laminated. When making the base material layer 1 into a multilayer structure, each resin film may be adhere | attached through an adhesive agent, and may be laminated | stacked directly without an adhesive agent. In the case of bonding without using an adhesive, for example, a method of bonding in a hot melt state such as a co-extrusion method, a sand lamination method, or a thermal laminating method can be mentioned. Moreover, when making it adhere | attach through an adhesive agent, the adhesive agent to be used may be a two-component curable adhesive, or a one-component curable adhesive. Further, the bonding mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curing type such as UV and EB, and the like. As an adhesive component, polyester resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose resin, (meth) acrylic resin Resins, polyimide resins, amino resins, rubbers, and silicon resins can be used.

  The base material layer 1 may be reduced in friction in order to improve moldability. In the case of reducing the friction of the base material layer 1, the friction coefficient of the surface is not particularly limited, but for example, 1.0 or less can be mentioned. In order to reduce the friction of the base material layer 1, for example, mat treatment, formation of a thin film layer of a slip agent, a combination thereof, and the like can be given.

  As the matting treatment, a matting agent is added to the base material layer 1 in advance to form irregularities on the surface, a transfer method by heating or pressurizing with an embossing roll, a surface is mechanically dry or wet blasting, or a file. There is a way to troll. Examples of the matting agent include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. The shape of the matting agent is not particularly limited, and examples thereof include a spherical shape, a fiber shape, a plate shape, an indeterminate shape, and a balloon shape. As a matting agent, specifically, talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, oxidation Aluminum, 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 melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like. These matting agents may be used individually by 1 type, and may be used in combination of 2 or more type. Among these matting agents, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. The matting agent may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment on the surface noodles.

  The thin film layer of the slip agent can be formed by depositing the slip agent on the surface of the base material layer 1 by bleeding out to form a thin layer, or by laminating the slip agent on the base material layer 1. The slip agent is not particularly limited. For example, erucic acid amide, stearic acid amide, behenic acid amide, ethylene bisoleic acid amide, ethylene bis stearic acid amide and other fatty acid amides, metal soap, hydrophilic silicone, and silicone grafted. Acryl, epoxy grafted with silicone, polyether grafted with silicone, polyester grafted with silicone, block-type silicone acrylic copolymer, polyglycerol-modified silicone, paraffin and the like. These slip agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  The thickness of the base material layer 1 is, for example, 7 to 75 μm, preferably 12 to 50 μm.

[Adhesive layer 2]
In the battery packaging material of the present invention, the adhesive layer 2 is a layer provided as necessary for the purpose of improving the adhesion between the base material layer 1 and the metal layer 3. The base material layer 1 and the metal layer 3 may be directly laminated.

  The adhesive layer 2 is formed of an adhesive resin capable of bonding the base material layer 1 and the metal layer 3. The adhesive resin used for forming the adhesive layer 2 may be a two-component curable adhesive resin or a one-component curable adhesive resin. Further, the adhesion mechanism of the adhesive resin used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot pressure type, and the like.

  Specific examples of the resin component of the adhesive resin that can be used for forming the adhesive layer 2 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester. Resin; Polyether adhesive; Polyurethane adhesive; Epoxy resin; Phenol resin resin; Polyamide resin such as nylon 6, nylon 66, nylon 12, copolymer polyamide; polyolefin, acid-modified polyolefin, metal-modified polyolefin, etc. Polyolefin resin; polyvinyl acetate resin; cellulose adhesive; (meth) acrylic resin; polyimide resin; amino resin such as urea resin and melamine resin; chloroprene rubber, nitrile rubber, steel Silicone resin; - down rubber such as butadiene rubber fluorinated ethylene propylene copolymer, and the like. These adhesive resin components may be used individually by 1 type, and may be used in combination of 2 or more type. The combination mode of two or more kinds of adhesive resin components is not particularly limited. For example, as the adhesive resin component, a mixed resin of polyamide and acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, polyamide and polyester, Examples thereof include a mixed resin of polyester and acid-modified polyolefin, and a mixed resin of polyester and metal-modified polyolefin. Among these, extensibility, durability under high-humidity conditions, anti-hypertensive action, thermal deterioration-preventing action during heat sealing, etc. are excellent, and a decrease in lamination strength between the base material layer 1 and the metal layer 3 is suppressed. From the viewpoint of effectively suppressing the occurrence of delamination, a polyurethane two-component curable adhesive resin; polyamide, polyester, or a blended resin of these with a modified polyolefin is preferable.

  The adhesive layer 2 may be multilayered with different adhesive resin components. When the adhesive layer 2 is multilayered with different adhesive resin components, the adhesive resin component disposed on the base material layer 1 side is used as the base material layer 1 from the viewpoint of improving the lamination strength between the base material layer 1 and the metal layer 3. It is preferable to select a resin having excellent adhesion to the metal layer 3 and to select an adhesive resin component having excellent adhesion to the metal layer 3 as the adhesive resin component disposed on the metal layer 3 side. When the adhesive layer 2 is multilayered with different adhesive resin components, specifically, the adhesive resin component disposed on the metal layer 3 side is preferably an acid-modified polyolefin, a metal-modified polyolefin, a polyester and an acid-modified polyolefin. And a resin containing a copolyester.

  About the thickness of the contact bonding layer 2, 1-50 micrometers, for example, Preferably 2-25 micrometers is mentioned.

[Metal layer 3]
In the battery packaging material of the present invention, the metal layer 3 is a layer that functions as a barrier layer for preventing the penetration of water vapor, oxygen, light, etc. into the battery, in addition to improving the strength of the packaging material. Specific examples of the metal forming the metal layer 3 include metal foils such as aluminum, stainless steel, and titanium. Among these, aluminum is preferably used. In order to prevent wrinkles and pinholes during the production of the packaging material, soft aluminum such as annealed aluminum (JIS A8021P-O) or (JIS A8079P-O) is used as the metal layer 3 in the present invention. Is preferred.

  About the thickness of the metal layer 3, 10-200 micrometers, for example, Preferably 15-100 micrometers is mentioned.

  Further, the metal layer 3 is preferably subjected to chemical conversion treatment on at least one surface, preferably at least the surface on the sealant layer 4 side, and more preferably both surfaces, for the purpose of stabilizing adhesion, preventing dissolution and corrosion, and the like. . Here, the chemical conversion treatment is a treatment for forming an acid-resistant film on the surface of the metal layer 3. Chemical conversion treatment is, for example, chromate chromate treatment using a chromic acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acetyl acetate, chromium chloride, potassium sulfate chromium, etc. ; Phosphoric acid chromate treatment using phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; aminated phenol heavy consisting of repeating units represented by the following general formulas (1) to (4) Examples thereof include chromate treatment using a coalescence.

In 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 represent 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, C1-C4 linear or branched alkyl groups, such as a tert- butyl group, are mentioned. Examples of the hydroxyalkyl group represented by X, R ₁ and R ₂ include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- A linear or branched chain having 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group An alkyl group is mentioned. be able to. In the general formulas (1) to (4), X is preferably any one of a hydrogen atom, a hydroxyl group, and a droxyalkyl group. The number average molecular weight of the aminated phenol polymer composed of the repeating units represented by the general formulas (1) to (4) is, for example, about 500 to about 1,000,000, preferably about 1000 to about 20,000.

  In addition, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 3, a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide, or barium sulfate fine particles dispersed in phosphoric acid is coated. A method of forming a corrosion-resistant treatment layer on the surface of the metal layer 3 by performing a baking treatment at 150 ° C. or higher can be mentioned. Moreover, you may form the resin layer which crosslinked the cationic polymer with the crosslinking agent on the corrosion-resistant process layer. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is grafted on an acrylic main skeleton, polyallylamine, or Examples thereof include aminophenols and derivatives thereof. These cationic polymers may be used individually by 1 type, and may be used in combination of 2 or more type. Examples of the crosslinking agent include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, silane coupling agents, and the like. These crosslinking agents may be used alone or in combination of two or more.

  These chemical conversion treatments may be performed alone or in combination of two or more chemical conversion treatments. Furthermore, these chemical conversion treatments may be carried out using one kind of compound alone, or may be carried out using a combination of two or more kinds of compounds. Among these, chromic acid chromate treatment is preferable, and chromate treatment in which a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer are combined is more preferable.

The amount of the acid-resistant film formed on the surface of the metal layer 3 in the chemical conversion treatment is not particularly limited. For example, if the chromate treatment is performed by combining a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer. The chromic acid compound is about 0.5 to about 50 mg, preferably about 1.0 to about 40 mg in terms of chromium, and the phosphorus compound is about 0.5 to about 50 mg in terms of phosphorus per 1 m ² of the surface of the metal layer 3. Is preferably about 1.0 to about 40 mg, and about 1 to about 200 mg, preferably about 5.0 to 150 mg of aminated phenol polymer.

  In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the metal layer 3 by a bar coating method, a roll coating method, a gravure coating method, a dipping method or the like, and then the temperature of the metal layer 3 is reached. Is performed by heating so as to be about 70 to 200 ° C. In addition, before the chemical conversion treatment is performed on the metal layer 3, the metal layer 3 may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the metal layer 3.

[Sealant layer 4]
In the battery packaging material of the present invention, the sealant layer 4 corresponds to the innermost layer, and the sealant layers 4 are heat-welded to each other to seal the battery element when the battery is assembled. The sealant layer 4 may be formed of a plurality of layers.

  When the sealant layer 4 does not have an adhesive layer 5 described later, the sealant layer 4 can be bonded to the metal layer 3, and the sealant layer 4 is formed of a resin that can be heat-sealed. Further, when the sealant layer 4 has an adhesive layer 5 described later, the sealant layer 4 can be bonded to the adhesive layer 5, and the sealant layer 4 is formed of a resin that can be heat-sealed. The resin forming the sealant layer 4 is not particularly limited as long as it has such characteristics, and examples thereof include acid-modified polyolefins, polyester resins, and fluorine resins. Moreover, when it has the contact bonding layer 5 mentioned later, in addition to these, the resin which forms polyolefin resin and the sealant layer 4 may be used individually by 1 type, and may be used in combination of 2 or more types.

The acid-modified polyolefin used for forming the sealant layer 4 is a polymer modified by graft polymerization of polyolefin with an unsaturated carboxylic acid. Specific examples of the acid-modified polyolefin include polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene, block copolymer of polypropylene (for example, block copolymer of propylene and ethylene) ), A random or amorphous polypropylene copolymer (for example, a random copolymer of propylene and ethylene), and a terpolymer of ethylene-butene-propylene. Among these polyolefins, from the viewpoint of heat resistance, polyolefins having at least propylene as a constituent monomer are preferable, and ethylene-butene-propylene terpolymers and propylene-ethylene random copolymers are more preferable. Examples of the unsaturated carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like. Among these unsaturated carboxylic acids, maleic acid and maleic anhydride are preferable. These acid-modified polyolefins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of the polyester resin used for forming the sealant layer 4 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and a copolymer mainly composed of ethylene terephthalate. Examples thereof include a polyester and a copolyester having butylene terephthalate as a main repeating unit. The copolymer polyester mainly composed of ethylene terephthalate is a copolymer polyester that polymerizes with ethylene isophthalate mainly composed of ethylene terephthalate (hereinafter, polyethylene (terephthalate / isophthalate)). Abbreviated), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). In addition, as a copolymer polyester mainly composed of butylene terephthalate as a repeating unit, specifically, a copolymer polyester that polymerizes with butylene isophthalate having butylene terephthalate as a repeating unit (hereinafter referred to as polybutylene (terephthalate / isophthalate)). For example), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyester resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of the fluororesin used for forming the sealant layer 4 include tetrafluoroethylene, trifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene, polychlorotrifluoroethylene, and ethylene chlorotrifluoroethylene. Examples thereof include a copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-based polyol. These fluororesins may be used alone or in combination of two or more.

  When the adhesive layer 5 is not provided, the sealant layer 4 may be formed of only an acid-modified polyolefin, a polyester resin, or a fluorine resin, and may contain a resin component other than these as required. When the sealant layer 4 contains a resin component other than the acid-modified polyolefin, the polyester resin, or the fluorine resin, the content of the acid-modified polyolefin, the polyester resin, or the fluorine resin in the sealant layer 4 is the effect of the present invention. Although it does not restrict | limit especially if it does not prevent, For example, 10-95 mass%, Preferably it is 30-90 mass%, Furthermore, 50-80 mass% is mentioned.

  In the sealant layer 4, in addition to the acid-modified polyolefin, the polyester resin, or the fluorine resin, examples of the resin component that can be contained as necessary include polyolefin.

  The polyolefin may have an acyclic structure or a cyclic structure. Specific examples of the acyclic polyolefin include polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene, block copolymer of polypropylene (for example, block copolymer of propylene and ethylene) And crystalline or amorphous polypropylene such as a random copolymer of polypropylene (for example, a random copolymer of propylene and ethylene); a terpolymer of ethylene-butene-propylene, and the like. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Etc. In addition, examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene, and the like. These polyolefins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among these polyolefins, those having characteristics as an elastomer (that is, polyolefin-based elastomers), particularly propylene-based elastomers, are preferable from the viewpoints of improving adhesive strength after heat sealing, preventing delamination after heat sealing, and the like. . Examples of the propylene-based elastomer include polymers containing propylene and one or more α-olefins having 2 to 20 carbon atoms (excluding propylene) as constituent monomers, and the number of carbon atoms constituting the propylene-based elastomer is 2. Specific examples of the α-olefin of ˜20 (excluding propylene) include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1 -Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like. These ethylene-based elastomers may be used alone or in combination of two or more.

  When the sealant layer 4 contains a resin component other than the acid-modified polyolefin, polyester resin, or fluororesin, the content of the resin component is appropriately set within a range that does not hinder the object of the present invention. For example, when a propylene elastomer is contained in the sealant layer 4, the content of the propylene elastomer in the sealant layer 4 is usually 5 to 70 mass%, preferably 10 to 60 mass%, more preferably 20 to 50 mass%. %.

  In the case where the adhesive layer 5 described later is provided between the metal layer 3 and the sealant layer 4, the resin for forming the sealant layer 4 is a polyolefin, in addition to the acid-modified polyolefin, polyester resin, fluorine resin, and the like. Examples thereof include modified cyclic polyolefin. These resins may be used alone or in combination of two or more.

  When the adhesive layer 5 is included, examples of the polyolefin that forms the sealant layer 4 include those exemplified above. The modified cyclic polyolefin is obtained by graft polymerization of a cyclic polyolefin with an unsaturated carboxylic acid. The cyclic polyolefin to be acid-modified is a copolymer of an olefin and a cyclic monomer. Examples of such olefins include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of the cyclic monomer include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene, and the like. Examples of the unsaturated carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like. Among these unsaturated carboxylic acids, maleic acid and maleic anhydride are preferable. These modified cyclic polyolefins may be used individually by 1 type, and may be used in combination of 2 or more type.

  When the adhesive layer 5 is provided, the sealant layer 4 may be formed of only an acid-modified polyolefin, a polyester resin, a fluorine-based resin, a polyolefin, or a modified cyclic polyolefin, and may contain other resin components as necessary. You may go out. When the sealant layer 4 contains a resin component other than these, the content of these resins in the sealant layer 4 is not particularly limited as long as the effect of the present invention is not hindered, for example, 10 to 95% by mass, preferably 30-90 mass%, Furthermore, 50-80 mass% is mentioned. Examples of the resin component that can be contained as necessary include those having the above-described characteristics as an elastomer. Moreover, about content of the resin component which can be contained as needed, it sets suitably in the range which does not disturb the objective of this invention. For example, when a propylene elastomer is contained in the sealant layer 4, the content of the propylene elastomer in the sealant layer 4 is usually 5 to 70 mass%, preferably 10 to 60 mass%, more preferably 20 to 50 mass%. %.

From the viewpoint of more effectively exerting the sealing and unsealing properties of the battery packaging material of the present invention, the melting point T _m1 of the sealant layer 4 is preferably 90 to 245 ° C, more preferably 100 to 220 ° C. It is done. From the same viewpoint, the softening point T _s1 of the sealant layer 4 is preferably 70 to 180 ° C., more preferably 80 to 150 ° C. Furthermore, from the same viewpoint, the melt flow rate (MFR) at 230 ° C. of the sealant layer 4 is preferably 1.5 to 25 g / 10 minutes, more preferably 3.0 to 18 g / 10 minutes.

Here, the melting point T _m1 of the sealant layer 4 is a value measured by the DSC method based on the melting point of the resin component constituting the sealant layer 4 in accordance with JIS K6921-2 (ISO 1873-2.2: 95). Further, when the sealant layer 4 is formed of a blend resin containing a plurality of resin components, the melting point T _m1 is obtained as described above for the melting point of each resin, and these are weighted averages by mass ratio. Can be calculated.

The softening point T _s1 of the sealant layer 4 is a value measured by a thermo-mechanical analysis method (TMA: Thermo-Mechanical Analyzer). Further, when the sealant layer 4 is formed of a blend resin containing a plurality of resin components, the softening point T _s1 is obtained as described above for the softening point of each resin, and these are expressed by mass ratio. It can be calculated by weighted average.

  The melt flow rate of the sealant layer 4 is a value measured by a melt flow rate measuring device in accordance with JIS K7210.

  Examples of the thickness of the sealant layer 4 include 12 to 120 μm, preferably 18 to 80 μm, and more preferably 20 to 60 μm.

  The sealant layer 4 may be a single layer or a multilayer. Further, the sealant layer 4 may contain a slip agent or the like as necessary. When the sealant layer 4 contains a slip agent, the moldability of the battery packaging material can be improved. Furthermore, in this invention, when the sealant layer 4 contains a slip agent, not only the moldability of a battery packaging material but also insulation can be improved. Although the detailed mechanism by which the insulating property of the battery packaging material is enhanced by including the slip agent in the sealant layer 4 is not necessarily clear, for example, it can be considered as follows. That is, when the sealant layer 4 contains a slip agent, when an external force is applied to the sealant layer 4, the molecular chain of the resin easily moves in the sealant layer 4, and cracks are less likely to occur. In particular, when the sealant layer 4 is formed of a plurality of types of resins, cracks are likely to occur at the interface existing between these resins, but the slip agent is present at such an interface. It is thought that it becomes possible to effectively suppress the occurrence of cracks when an external force is applied by making the resin easy to move. By such a mechanism, it is thought that the fall of the insulating property by a crack producing in a sealant layer is suppressed.

  The slip agent is not particularly limited, and a known slip agent can be used, and examples thereof include those exemplified for the base material layer 1 described above. A slip agent may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the slip agent in the sealant layer 4 is not particularly limited, and is preferably about 0.01 to 0.2% by mass, more preferably 0 from the viewpoint of improving the moldability and insulation of the electronic packaging material. About 0.05 to 0.15 mass%.

  Moreover, as thickness of the sealant layer 4, for example, 5-40 micrometers, Preferably it is 10-35 micrometers, More preferably, 15-30 micrometers is mentioned.

[Adhesive layer 5]
In the battery packaging material of the present invention, an adhesive layer is provided between the metal layer 3 and the sealant layer 4 for the purpose of firmly bonding the metal layer 3 and the sealant layer 4 as shown in FIG. 5 may be further provided. The adhesive layer 5 may be formed of one layer or may be formed of a plurality of layers.

  The adhesive layer 5 is formed of a resin capable of bonding the metal layer 3 and the sealant layer 4. The resin forming the adhesive layer 5 is not particularly limited as long as it is a resin capable of adhering the metal layer 3 and the sealant layer 4, but preferably the acid-modified polyolefin, polyester resin, fluorine resin, or polyether resin described above. , Polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose resin, (meth) acrylic resin, polyimide resin, amino resin, rubber, silicon Examples thereof include resins. The resin forming the adhesive layer 5 may be used alone or in combination of two or more.

  The adhesive layer 5 may be formed of at least one of these resins, and may contain other resin components as necessary. When the adhesive layer 5 contains other resin components, the acid-modified polyolefin, polyester resin, fluororesin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin in the sealant layer 4 Resin, polyolefin resin, polyvinyl acetate resin, cellulose resin, (meth) acrylic resin, polyimide resin, amino resin, rubber, and silicon resin content, as long as the effects of the present invention are not hindered Although it does not restrict | limit in particular, For example, 10-95 mass%, Preferably it is 30-90 mass%, Furthermore, 50-80 mass% is mentioned.

  Moreover, it is preferable that the contact bonding layer 5 further contains a hardening | curing agent. When the adhesive layer 5 contains a curing agent, the mechanical strength of the adhesive layer 5 can be increased, and the insulation of the battery packaging material can be effectively increased. A hardening | curing agent may be used individually by 1 type, and may be used in combination of 2 or more types.

  Curing agents are acid-modified polyolefin, polyester resin, fluorine resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose resin , (Meth) acrylic resin, polyimide resin, amino resin, rubber, or silicon resin is not particularly limited. As a hardening | curing agent, a polyfunctional isocyanate compound, a carbodiimide compound, an epoxy compound, an oxazoline compound etc. are mentioned, for example.

  The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate compound include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), those obtained by polymerizing or nurate, mixtures thereof, Examples include copolymers with other polymers.

  The carbodiimide compound is not particularly limited as long as it is a compound having at least one carbodiimide group (—N═C═N—). As the carbodiimide compound, a polycarbodiimide compound having at least two carbodiimide groups is preferable. Specific examples of particularly preferred carbodiimide compounds include the following general formula (5):

[In General formula (5), n is an integer greater than or equal to 2. ]
A polycarbodiimide compound having a repeating unit represented by:
The following general formula (6):

[In General formula (6), n is an integer greater than or equal to 2. ]
A polycarbodiimide compound having a repeating unit represented by:
And the following general formula (7):

[In General formula (7), n is an integer greater than or equal to 2. ]
The polycarbodiimide compound represented by these is mentioned. In general formula (4)-(7), n is an integer of 30 or less normally, Preferably it is an integer of 3-20.

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

  The oxazoline compound is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline compound include Epocross series manufactured by Nippon Shokubai Co., Ltd.

  From the standpoint of increasing the mechanical strength of the adhesive layer 5, the curing agent may be composed of two or more types of compounds.

  In the adhesive layer 5, the content of the curing agent is acid-modified polyolefin, polyester resin, fluorine resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, poly It should be in the range of 0.1 to 50 parts by weight with respect to 100 parts by weight of vinyl acetate resin, cellulose resin, (meth) acrylic resin, polyimide resin, amino resin, rubber, or silicon resin. It is more preferable that it is in the range of 0.1 to 30 parts by mass. Further, in the adhesive layer 5, the content of the curing agent is preferably in the range of 1 equivalent to 30 equivalents as a reactive group in the curing agent with respect to 1 equivalent of the carboxyl group in each resin such as acid-modified polyolefin. More preferably, it is in the range of 1 equivalent to 20 equivalents. Thereby, the insulation and durability of the battery packaging material can be further improved.

  When the adhesive layer 5 includes a curing agent, the adhesive layer 5 may be formed of a two-component curable adhesive resin or a one-component curable adhesive resin. Further, the bonding mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curing type such as UV and EB, and the like.

From the viewpoint of more effectively achieving the sealing and unsealing properties of the battery packaging material of the present invention, the melting point T _m2 of the adhesive layer 5 is preferably 90 to 245 ° C, more preferably 100 to 230 ° C. . From the same viewpoint, the softening point T _s2 of the adhesive layer 5 is preferably 70 to 180 ° C., more preferably 80 to 150 ° C.

The calculation method of the melting point T _m2 and the softening point T _s2 of the adhesive layer 5 is the same as that for the sealant layer 4.

  Although it does not restrict | limit especially as thickness of the contact bonding layer 5, Preferably it is 0.01 micrometer or more, More preferably, 0.05-20 micrometers is mentioned. If the thickness of the adhesive layer 5 is less than 0.01 μm, it may be difficult to stably bond the metal layer 3 and the sealant layer 4.

4). 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 layers having a predetermined composition are laminated is obtained. For example, the following method is exemplified. .

  First, a laminated body (hereinafter, also referred to as “laminated body A”) in which a base material layer 1, an adhesive layer 2, and a metal layer 3 are sequentially laminated as necessary is formed. The formation of the laminate A in the case of having the adhesive layer 2 is specifically a thermal laminating method or a sand laminating method of the base material layer 1, the adhesive layer 2, and the metal layer 3 whose surface is subjected to chemical conversion treatment as necessary. , By laminating by a dry lamination method, a melt extrusion method, a co-extrusion method, or a combination thereof. In addition, in the formation of the laminate A, the stability of the adhesion between the base material layer 1 and the metal layer 3 by the adhesive layer 2 is increased by performing an aging treatment, a water treatment, a heat treatment, an electron beam treatment, an ultraviolet treatment, or the like. obtain. Moreover, as a method of laminating the base material layer 1 directly on the metal layer 3 to form the laminate A, the laminate A is laminated by a thermal lamination method, a solution coating method, a melt extrusion method, a co-extrusion method, or a combination thereof. A method is mentioned. Under the present circumstances, stability of adhesion | attachment with the base material layer 1 and the metal layer 3 can be improved by performing an aging process, a hydration process, a heat processing, an electron beam process, an ultraviolet-ray process, etc.

  In the formation of the laminate A by the dry laminating method, for example, the resin constituting the adhesive layer 2 is dissolved or dispersed in water or an organic solvent, and the solution or dispersion is coated on the base material layer 1 to form water. Or after drying the organic solvent, after forming the contact bonding layer 2 on the base material layer 1, the metal layer 3 can be thermocompression-bonded and performed.

  The laminate A is formed by the thermal laminating method. For example, a multilayer film in which the base material layer 1 and the adhesive layer 2 are laminated is prepared in advance, and the metal layer 3 is superimposed on the adhesive layer 2 and heated with a heating roll. It can be performed by thermocompression bonding with the adhesive layer 2 sandwiched between the layer 1 and the metal layer 3. The laminate A is formed by the thermal laminating method in which a multilayer film in which the metal layer 3 and the adhesive layer 2 are laminated is prepared in advance, and the base material layer 1 is superposed on the heated metal layer 3 and the adhesive layer 2. It may be performed by thermocompression bonding while sandwiching the adhesive layer 2 between the base material layer 1 and the metal layer 3.

  In addition, the multilayer film in which the base material layer 1 and the adhesive layer 2 prepared in advance in the thermal laminating method are laminated on the resin film constituting the base material layer 1 by melt extrusion or solution coating of the adhesive constituting the adhesive layer 2. After being laminated and dried by (liquid coating), the adhesive layer 2 is formed by baking at a temperature equal to or higher than the melting point of the adhesive. By performing baking, the adhesive strength between the metal layer 3 and the adhesive layer 2 is improved. Similarly, for a multilayer film in which the metal layer 3 and the adhesive layer 2 prepared in advance in the thermal laminating method are laminated, the adhesive constituting the adhesive layer 2 is melt-extruded or solution into the metal foil constituting the metal layer 3 in the same manner. After being laminated by coating and dried, it is formed by baking at a temperature equal to or higher than the melting point of the adhesive constituting the adhesive layer 2.

  The laminate A is formed by the sand lamination method, for example, by melting and extruding the adhesive constituting the adhesive layer 2 onto the upper surface of the metal layer 3 and bonding the resin film constituting the base material layer 1 to the metal layer. Can be performed. At this time, it is desirable that the resin film is bonded and temporarily bonded, and then heated again to perform the main bonding. In the sand lamination method, the adhesive layer 2 may be multilayered with different resin types. In this case, a multilayer film in which the base material layer 1 and the adhesive layer 2 are laminated is prepared in advance, the adhesive constituting the adhesive layer 2 is melt-extruded on the upper surface of the metal layer 3, and the multilayer resin film and the thermal lamination method are used. What is necessary is just to laminate. Thereby, the adhesive layer 2 which comprises a multilayer film, and the adhesive layer 2 laminated | stacked on the upper surface of the metal layer 3 adhere | attach, and the two-layer adhesive layer 2 is formed. When the adhesive layer 2 is multilayered with different resin types, a multilayer film in which the metal layer 3 and the adhesive layer 2 are laminated is prepared in advance, and the adhesive constituting the adhesive layer 2 is melted on the base material layer 1 It may be extruded and laminated with the adhesive layer 2 on the metal layer 3. Thereby, the adhesive layer 2 composed of two different adhesives is formed between the multilayer resin film and the base material layer 1.

  Next, the sealant layer 4 is laminated on the metal layer 3 of the laminate A. Lamination of the sealant layer 4 on the metal layer 3 of the laminate A can be performed by a coextrusion method, a thermal lamination method, a sand lamination method, a coating method, or a combination thereof. For example, when the adhesive layer 5 is not provided, the sealant layer 4 can be formed on the metal layer 3 by melt extrusion, thermal lamination, coating, or the like. When the adhesive layer 5 is provided, the sealant layer 4 can be formed by the same method after the adhesive layer 5 is formed on the metal layer 3 by a melt extrusion method, a thermal laminating method, a coating method, or the like. Further, a co-extrusion method in which the adhesive layer 5 and the sealant layer 4 are simultaneously melt-extruded on the metal layer 3 may be performed. Moreover, while the adhesive layer 5 is melt-extruded on the metal layer 3, a sand laminating method in which the film-like sealant layer 4 is bonded can also be performed. When the sealant layer 4 is formed of two layers, for example, one layer of the adhesive layer 5 and the sealant layer 4 is coextruded on the metal layer 3, and then another layer of the sealant layer 4 is pasted by a thermal lamination method. The method of attaching is mentioned. Further, there may be mentioned a method in which one layer of the adhesive layer 5 and the sealant layer 4 is coextruded on the metal layer 3 and another layer of the film-like sealant layer 4 is bonded. In addition, when making the sealant layer 4 into three or more layers, the sealant layer 4 can be further formed by a melt extrusion method, a thermal lamination method, a coating method, or the like.

  As described above, base material layer 1 / adhesive layer 2 formed as necessary / metal layer 3 whose surface is subjected to chemical conversion treatment as needed / adhesive layer 5 formed as needed / sealant layer 4 A laminated body made of is formed. In order to strengthen the adhesiveness of the adhesive layer 2, it may be further subjected to heat treatment such as hot roll contact, hot air, near or far infrared irradiation, dielectric heating, heat resistance heating and the like. Examples of such heat treatment conditions include 150 to 250 ° C. and 1 to 10 hours.

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

When packaging a battery element using the battery packaging material of the present invention, the two battery packaging materials may be the same or different. Specific examples of the laminated structure of each battery packaging material in the case of packaging a battery element using two different battery packaging materials include the following.
One battery packaging material: base material layer 1 (nylon layer) / adhesive layer 2 (two-component curable polyester resin layer) / metal layer 3 (aluminum foil layer) / adhesive layer 5 (acid-modified polypropylene layer) / sealant layer 4 (polypropylene layer)
The other battery packaging material: base material layer 1 (acrylic-urethane coating layer) / metal layer 3 (stainless steel layer) / adhesive layer 5 (fluorine-based resin layer) / sealant layer 4 (polypropylene)

5. Characteristics and Applications of Battery Packaging Material The battery packaging material of the present invention can maintain the sealed state of the battery element until the pressure or temperature in the battery rises to a certain level. When the temperature rises continuously, it can be opened quickly and gently to suppress excessive expansion of the battery packaging material, runaway battery reaction, ignition, and the like. In particular, in the battery packaging material of the present invention, peeling occurs at least partially between the metal layer 3 and the outer surface of the sealant layer 4 until the pressure or temperature in the battery rises to a certain level, When the inner bag is formed at the part where peeling occurs, and then the inner bag is opened and the packaging material is opened, the packaging material can be opened more gently, excessive expansion of the battery packaging material, runaway battery reaction, ignition Etc. can be suppressed more effectively. More specific characteristics of the battery packaging material of the present invention include, for example, a temperature increase from room temperature 25 ° C. to 5 ° C./min under atmospheric pressure in a state where the sealant layers 4 are heat sealed to form a sealed space. When the temperature is increased at a speed, the packaging material does not open until reaching a certain temperature (set temperature T ° C.) in the range of 100 to 160 ° C., and then the packaging material can be gently opened. . For example, the battery packaging material of the present invention has a characteristic that the packaging material does not open until the above certain temperature is reached under the heating conditions shown below, and gently opens after reaching the opening temperature. It becomes possible.
<Heating conditions>
(1) A recess having a depth of 3 mm, a length of 35 and a width of 50 mm is formed at the center of the battery packaging material cut into a shape having a length of 80 mm and a width of 150 mm, and is formed into a shape having an edge around the recess.
(2) The edges are overlapped so that the molded sealant layer 4 of the battery packaging material and the other unformed sealant layer 4 of the battery packaging material face each other, and the edges are heat-sealed ( 175 ° C. and surface pressure of 1.4 MPa for 3 seconds) to form a case having a sealed internal space (pressure 1 atm).
(3) The battery packaging material in the above case is put in an oven under atmospheric pressure and heated to a set temperature T ° C. between 100 to 160 ° C. at a rate of temperature increase of 5 ° C./min. After reaching the temperature T ° C., the set temperature T ° C. is maintained.

  From the viewpoint of more effectively achieving the sealing and unsealing properties of the battery packaging material of the present invention, in the battery packaging material of the present invention, the laminate strength between the metal layer 3 and the sealant layer 4 at 25 ° C. , Preferably 3 (N / 15 mm) or more, more preferably 4 to 20) (N / 15 mm). If the laminate strength at 25 ° C. is too low, the laminate may be opened before reaching the set temperature. From the same viewpoint, the laminate strength between the metal layer 3 and the sealant layer 4 at 80 ° C. is preferably 2.5 (N / 15 mm) or more, more preferably 3 to 20 (N / 15 mm). Can be mentioned. Even when the laminate strength at 80 ° C. is too low, the laminate may be opened at a temperature lower than 80 ° C. Furthermore, from the same viewpoint, the laminate strength of the metal layer 3 and the sealant layer 4 at 125 ° C. is 2.5 (N / 15 mm) or less, more preferably 0.1 to 2.2 (N / 15 mm). Can be mentioned. If the laminate strength at 125 ° C. is too high, the battery packaging material will not be opened quickly even if the set temperature is exceeded, and the battery will rapidly open in a state where the temperature and internal pressure are very high. Or the battery element may pop out.

  From the same point of view, in the battery packaging material of the present invention, the sealing strength of the part that is heat sealed (heat sealing condition: 190 ° C., surface pressure: 1.0 MPa for 3 seconds) with the sealant layers 4 facing each other. As at 25 degreeC, Preferably it is 30 (N / 15mm) or more, More preferably, 40-200 (N / 15mm) is mentioned. If the seal strength at 25 ° C. is too low, the seal may be opened before reaching the set temperature. From the same point of view, in the battery packaging material of the present invention, the sealing strength of the part that is heat sealed (heat sealing condition: 190 ° C., surface pressure: 1.0 MPa for 3 seconds) with the sealant layers 4 facing each other. As, in 125 degreeC, Preferably it is 20 (N / 15mm) or less, More preferably, 5-16 (N / 15mm) is mentioned. If the sealing strength at 125 ° C. is too high, the battery packaging material will not be opened quickly even if the set temperature is exceeded, and the battery will rapidly open in a state where the temperature and internal pressure are very high, and the electrolyte inside the battery Or the battery element may pop out.

  Further, from the same viewpoint, in the battery packaging material of the present invention, a bag obtained by heat sealing (heat sealing conditions: 190 ° C., surface pressure of 1.0 MPa for 3 seconds) with the sealant layers 4 facing each other. The laminate strength of the metal layer and the sealant layer after standing for 24 hours at 85 ° C. in the state where the inner space of the bag-like packaging material contains the electrolyte solution is 0.1 ( N / 15 mm) or more, and more preferably 0.2 (N / 15 mm) or more. When the laminate strength when contacted with the electrolyte is too low, when the battery is stored at a high temperature, or between the metal layer 3 and the sealant layer 4 due to heat generated by charging / discharging of the battery, Delamination may occur and the strength of the battery packaging material may be insufficient.

  The battery packaging material of the present invention has the opening characteristics described above, and is gently opened by micro-cleavage when opened. For this reason, when the battery packaging material of the present invention is heated to a certain set temperature T ° C., the packaging material is not opened until the temperature reaches T ° C., and the packaging material is quickly opened after reaching T ° C. Thus, the battery can be suitably used as a packaging material for the battery. The set temperature T determined by the battery is set, for example, between 100 and 160 ° C., preferably between 120 and 150 ° C., and is set according to the type of battery to be packaged, usage, safety standards, and the like. The temperature is different. For example, some batteries have a set temperature T set to 100 ° C., while other batteries have a set temperature T set to 160 ° C. for safety standards. The battery packaging material of the present invention is provided as a packaging material having a sealing property and an opening property corresponding to a set temperature required by a battery to be applied. In addition, the time required for the battery to transition to the unsealed state after reaching T ° C. is determined within a range in which safety can be ensured, and varies depending on the type and use of the battery, the rate of temperature increase, etc. Is within 60 minutes, more preferably within 30 minutes, and the battery packaging material of the present invention can satisfy the time.

  Specifically, the battery packaging material of the present invention can be used for sealing and housing battery elements such as a positive electrode, a negative electrode, and an electrolyte, and is provided with a space for housing the battery element. . The space is formed, for example, by press molding a laminated sheet cut into a short shape.

  More specifically, a battery element including at least a positive electrode, a negative electrode, and an electrolyte, with 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 packaging material is used by covering the periphery of the battery element so that a flange portion (region where the sealant layers 4 are in contact with each other) can be formed and heat sealing the sealant layers 4 of the flange portion together. Batteries are provided. In addition, when accommodating a battery element using the battery packaging material of the present invention, it is used so that the sealant layer 4 of the battery packaging material of the present invention is inside (surface in contact with the battery element).

  The battery packaging material of the present invention may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery to which the battery packaging material of the present invention is applied is not particularly limited. For example, a lithium ion battery, a lithium ion polymer battery, a lead battery, a nickel / hydrogen battery, a nickel / cadmium battery , Nickel / iron livestock batteries, nickel / zinc livestock batteries, silver oxide / zinc livestock batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are suitable applications for the battery packaging material of the present invention.

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

Example 1-17 and Comparative Example 1-4
[Manufacture of battery packaging materials]
On the base material layer 1 made of a biaxially stretched nylon film (thickness 25 μm), a metal layer 3 made of an aluminum foil (thickness 40 μm) subjected to chemical conversion treatment on both surfaces was laminated by a dry lamination method. Specifically, a two-component urethane adhesive (a polyester-based main component and an isocyanate-based curing agent) was applied to one surface of an aluminum foil, and an adhesive layer 2 (thickness 4 μm) was formed on the metal layer 3. . Next, after bonding the adhesive layer 2 and the base material layer 1 on the metal layer 3 under pressure and heating, an aging treatment is performed at 60 ° C. for 24 hours, whereby base material layer 1 / adhesive layer 2 / metal layer 3 A laminate was prepared. In addition, the chemical conversion treatment of the aluminum foil used as the metal layer 3 is performed by rolling a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg / m ² (dry weight). The coating was applied to both surfaces of the aluminum foil and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher.

  Then, in Examples 1 to 3, the sealant layer 4 was laminated on the metal layer 3 in Examples 1 to 3, respectively. In Examples 4 to 17, the adhesive layer was formed on the metal layer 3. 5 and the sealant layer 4 were laminated. The structures of the adhesive layer 5 and the sealant layer 4 are as shown in Table 1. Moreover, about melting | fusing point of the contact bonding layer 5 and the sealant layer 4, it is the value which measured melting | fusing point of resin by the differential scanning calorimetry method (DSC method). About the softening point of the contact bonding layer 5 and the sealant layer 4, it is the value which measured the softening point of resin by the thermomechanical analysis method (TMA method). In addition, when resin is blended, it is the value calculated by measuring melting | fusing point and softening point of each resin, and carrying out the weighted average by this. Thus, a battery packaging material comprising a laminate in which the base material layer 1 / adhesive layer 2 / metal layer 3 / adhesive layer 5 (not in Examples 1 to 3) / sealant layer 4 were laminated in order was obtained.

[Evaluation of sealing and unsealing properties of battery packaging materials]
After each battery packaging material is cut to 80 mm × 150 mm, a 35 mm × 50 mm diameter mold (female mold) and a corresponding mold (male mold) with a 0.4 MPa pressure of 3.0 mm Cold forming to a depth, a recess was formed at the center. A stainless steel plate having a thickness of 32 mm × 48 mm × 3 mm was placed in the concave portion as a battery element, and then an electrolytic solution (1M LiPF ₆ , ethylene carbonate, diethyl carbonate and dimethyl carbonate (capacity ratio 1: 1: 1). 3 g) of the mixed solution. Next, another unmolded battery packaging material was stacked from above the recesses so that the sealant layers were opposed to each other, and the peripheral portion was heat-sealed to prepare a pseudo battery. The heat sealing conditions were 175 ° C. and surface pressure of 1.4 MPa for 3 seconds. The obtained pseudo battery was placed in an oven, and the temperature was increased from room temperature 25 ° C. to 150 ° C. at a temperature increase rate of 5 ° C./min under atmospheric pressure. Further, after reaching 150 ° C., it was maintained for 60 minutes. Moreover, the evaluation of the openability of the pseudo battery was performed at a temperature at which the inner bag was formed on the pseudo battery, a temperature at which the inner bag was cleaved, or 150 ° C. when the inner bag was not cleaved when reaching 150 ° C. The time until the battery packaging material was opened after reaching to was visually observed. Further, the position where peeling occurred was visually observed. The temperature was measured with a thermocouple attached to the outside of the pseudo battery. The results are shown in Table 2.

[Measurement of laminate strength]
Under each temperature shown in Table 2, each of the above-mentioned cut battery packaging materials was subjected to a tension tester (manufactured by Shimadzu Corp., AGS-50D (trade name)) with a metal layer and a sealant layer of 50 mm / min. The peel strength was 10 mm, and the maximum strength at the time of peeling was defined as the laminate strength.

[Confirmation of electrolyte resistance]
After each battery packaging material is cut to 80 mm × 150 mm, a 35 mm × 50 mm diameter mold (female mold) and a corresponding mold (male mold) with a 0.4 MPa pressure of 3.0 mm Cold forming to a depth, a recess was formed at the center. The recess was filled with 3 g of the above electrolyte solution, and another battery packaging material was stacked on the recess so that the sealant layers were opposed to each other, and the peripheral portion was heat-sealed. The heat sealing conditions were 190 ° C. and a surface pressure of 1.0 MPa for 3 seconds. This was stored at 85 ° C. for 1 day, then opened and visually checked for delamination between the metal layer and the sealant layer. The results are shown in Table 2.

[Measurement of seal strength]
The battery packaging materials were stacked with the sealant layers facing each other, heat sealed under conditions of 190 ° C. and a surface pressure of 1.0 MPa for 3 seconds, then left at the temperatures shown in Table 2 for 2 minutes, and then pulled. The sealant layer of the heat seal part was peeled 10 mm at a rate of 30 mm / min with a tester (manufactured by Shimadzu Corporation, AGS-50D (trade name)), and the maximum strength at the time of peeling was defined as the seal strength. The results are shown in Table 2.

The resins shown in Table 1 are as follows.
PP (A): Random polypropylene Melting point 160 ° C Softening point 110 ° C
PP (B): Random polypropylene Melting point 140 ° C Softening point 110 ° C
PP (C): Block polypropylene Melting point 163 ° C Softening point 90 ° C
PP (D): Random polypropylene Melting point 130 ° C Softening point 70 ° C
PP (E): Random polypropylene Melting point 140 ° C Softening point 70 ° C
PP (F): Block polypropylene Melting point 160 ° C Softening point 90 ° C
LLDPE: Linear low density polyethylene Melting point 120 ° C Softening point 75 ° C
LDLE: Low density polyethylene Melting point 110 ° C Softening point 90 ° C
Acid-modified PP (A): Carboxylic acid-modified polypropylene Melting point 140 ° C Softening point 110 ° C
Acid-modified PP (B): Carboxylic acid-modified polypropylene Melting point 140 ° C Softening point 80 ° C
Acid-modified PP (C): Carboxylic acid-modified polypropylene Melting point 160 ° C Softening point 120 ° C
Acid-modified PP (D): Carboxylic acid-modified polypropylene Melting point 160 ° C Softening point 80 ° C
Acid-modified PP (E): Carboxylic acid-modified polypropylene Melting point 140 ° C Softening point 120 ° C
Acid-modified PP (F): Isocyanic cured product of carboxylic acid-modified polypropylene Acid-modified PP (G): Cross-linked product of oxazoline and epoxy of carboxylic acid-modified polypropylene Acid-modified PE (A): Carboxylic acid-modified linear low-density polyethylene Melting point 120 ° C Softening point 75 ° C
Acid-modified PE (B): Carboxylic acid-modified low-density polyethylene Melting point 110 ° C Softening point 85 ° C
Acid-modified PE (C): Carboxylic acid-modified low density polyethylene Melting point 110 ° C Softening point 102 ° C
Acid-modified PE (D): Ethylene / vinyl acetate copolymer Melting point 92 ° C Softening point 50 ° C
Fluorine resin (A): Polychlorotrifluoroethylene Melting point 220 ° C Softening point 85 ° C
Fluorine-based resin (B): two-component curable fluorine-based adhesive (fluorine polyol resin with isophorone diisocyanate (IPDI) -based curing agent melting point 95 ° C. softening point 65 ° C.

  As shown in Table 2, in the battery packaging materials of Examples 1 to 17, when the pseudo battery is heated, in any place between the metal layer and the outer surface (the innermost layer side surface) of the sealant layer Peeling occurred and an inner bag was formed. Furthermore, after that, the inner bag was cleaved, and the battery packaging material was quickly and gently opened. On the other hand, when the battery packaging materials of Comparative Examples 1 and 3 were used, peeling did not occur even when the pseudo battery was heated, and no inner bag was formed. Then, when the internal temperature of the pseudo battery reached 150 ° C., the pseudo battery expanded, and the electrolyte was ejected all at once as the gas was released, and the electrolyte was scattered around. Further, the battery packaging material of Comparative Example 2 has a laminate strength at 80 ° C. that is too low, and after being filled with the electrolyte, it is easily peeled off by hand between the adhesive layer and the sealant layer. As it was not usable. Moreover, also in the battery packaging material of Comparative Example 4, the laminate strength at 80 ° C. was too low, and sudden peeling occurred inside the sealant layer at a low temperature of 80 ° C. From the above results, in order for the battery packaging material of the present invention to exhibit the opening mechanism of the present invention, the laminate strength is 3 (N / 15 mm) or more at 25 ° C. and 2 at 80 ° C. as described above. 0.5 (N / 15 mm) or more and 2.5 (N / 15 mm) or less at 125 ° C., and the seal strength is 30 (N / 15 mm) or more at 25 ° C. and 20 (N / 15 mm) or less at 125 ° C. Thus, it can be seen that it is preferable to adjust the composition, melting point, and the like of the sealant layer 4 and the adhesive layer 5.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Metal layer 5 Adhesive layer 4 Sealant layer 10 Fine cleavage

Claims (10)

A battery packaging material comprising a laminate having at least a base material layer, a metal layer, and a sealant layer in this order,
When the battery packaging material is heat sealed and the battery element is heated in a sealed state, after peeling occurs in at least a part between the metal layer and the outer surface of the sealant layer while maintaining the sealed state The battery element can be kept sealed until the pressure or temperature in the battery rises to a certain level, and the pressure or temperature in the battery continues to rise. A packaging material for a battery, in which a minute tear is rapidly generated in the sealant layer at a part peeled when the state has been automatically advanced, leading to a gentle opening .   2. The battery packaging material according to claim 1, wherein after the inner bag is formed at the part where the peeling occurs, the inner bag is opened so that the inner bag is opened and moved to the opened state.   The battery packaging material according to claim 1, further comprising an adhesive layer between the base material layer and the metal layer.   The battery packaging material according to claim 1, further comprising an adhesive layer between the metal layer and the sealant layer.   The peeling includes an interface between the metal layer and the sealant layer, an interface between the metal layer and the adhesive layer, an interface between the adhesive layer and the sealant layer, an inside of the adhesive layer, and an inside of the sealant layer. The battery packaging material according to claim 1, wherein the battery packaging material is generated at least at one location.   The battery packaging material according to any one of claims 1 to 5, wherein a laminate strength between the metal layer and the sealant layer at 25 ° C is 3 (N / 15 mm) or more.   The laminate strength between the metal layer and the sealant layer at 80 ° C. is 2.5 (N / 15 mm) or more, and the laminate strength between the metal layer and the sealant layer at 125 ° C. is 2. The battery packaging material according to claim 1, which is 5 (N / 15 mm) or less.   The battery packaging material according to any one of claims 1 to 7, wherein a seal strength of a portion heat-sealed with the sealant layers facing each other is 30 (N / 15 mm) or more at 25 ° C.   The battery packaging material according to any one of claims 1 to 8, wherein a seal strength of a portion heat-sealed with the sealant layers facing each other is 20 (N / 15 mm) or less at 125 ° C. In the bag-shaped packaging material obtained by heat-sealing with the sealant layers facing each other, after leaving the electrolyte solution in the internal space of the bag-shaped packaging material for 24 hours at 85 ° C., The battery packaging material according to claim 1, wherein the heat-sealed portion has a sealing strength of 0.2 (N / 15 mm) or more.