JP2017069210A - Packaging material for electrochemical cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide packaging material for an electrochemical cell, excellent in resistance to an electrolytic solution.SOLUTION: In packaging material 110 for an electrochemical cell, at least a base material layer 112, an adhesive layer 113, a barrier layer 114 composed of a metal foil, and a thermally adhesive layer 116 composed of thermally adhesive resin are laminated sequentially from the outside. A protective layer 111 composed of resin comprising a main agent, a hardener and an amine-containing crosslinking agent is provided on an external surface of the base material layer 112.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a packaging material for an electrochemical cell for packaging an electrochemical cell.

  A conventional packaging material for electrochemical cells is disclosed in Patent Document 1. This packaging material is a laminate in which an outermost base material layer, a barrier layer, and an innermost thermal adhesive layer are sequentially laminated, and the periphery of the electrochemical cell is heat-sealed with the thermal adhesive layers facing each other. A package is formed. The package is provided with a space for storing battery elements such as an electrolytic solution and a separator, and the storage space is formed by press-molding a packaging material cut into a rectangular shape.

  In recent years, electronic devices equipped with electrochemical cells have been reduced in size and thickness, and it is necessary to mold the packaging of electrochemical cells into a thin and sharp shape in order to store the electrochemical cells in a narrow space. . For this reason, in patent document 1, the resin film which is excellent in a drawability is used for the base material layer.

JP 2008-288117 A

  However, according to the packaging material, there is a problem in that when the electrolytic solution adheres to the upper surface of the packaging body when the electrolytic solution is sealed inside the packaging body, the resin film of the base material layer is corroded and whitened by the electrolytic solution.

  An object of this invention is to provide the packaging material for electrochemical cells which is excellent in electrolyte solution resistance in view of the said problem.

  In order to achieve the above object, the present invention provides an electrochemical cell packaging material in which at least a base material layer, an adhesive layer, a barrier layer made of a metal foil, and a thermal adhesive layer made of a thermoadhesive resin are sequentially laminated from the outside. And the protective layer comprised with resin which consists of a main ingredient, a hardening | curing agent, and the crosslinking agent containing an amine was provided in the outer surface of the said base material layer, It is characterized by the above-mentioned.

  According to this configuration, the protective layer formed of a resin containing an amine as a crosslinking agent is excellent in resistance to electrolytic solution, and the electrolytic solution penetrates the protective layer against the adhesion of the electrolytic solution and corrodes the base material layer. prevent. Thereby, generation | occurrence | production of the whitening resulting from corrosion of a base material layer is prevented. Further, the electrolytic resistance of the protective layer is hardly lowered even in a region where the base material layer is stretched in press molding. Therefore, even when the electrolytic solution adheres to the corner portion of the packaging material for electrochemical cells after press molding, whitening due to corrosion of the base material layer can be prevented. In addition, the protective layer formed of a resin containing an amine as a crosslinking agent is excellent in alcohol resistance and heat resistance. By having alcohol resistance, the surface of the protective layer hardly undergoes deformation or discoloration of the surface of the protective layer with respect to wiping with alcohol. Moreover, by having heat resistance, it is difficult for deformation and discoloration of the protective layer to occur with respect to the thermal history of the lamination process of the packaging material for electrochemical cells.

  Moreover, the present invention is characterized in that, in the electrochemical cell packaging material having the above-described configuration, the amine contained in the crosslinking agent is benguanamine, melamine, or a mixture of benzoguanamine and melamine. According to this configuration, the electrolytic solution resistance, alcohol resistance, and heat resistance of the protective layer are further improved.

  In the electrochemical cell packaging material having the above-described structure, the present invention is characterized in that the resin constituting the protective layer contains a matting agent. According to this configuration, fine irregularities are formed on the surface of the protective layer, and the appearance of the packaging material for electrochemical cells is formed in a matte tone (matte tone). In addition, due to the fine unevenness, the coefficient of dynamic friction on the surface of the protective layer is lowered and the slipperiness is improved. Thereby, for example, when the packaging material for electrochemical cells is press-molded using a molding die, the base material layer is stretched while following the barrier layer against the deformation of the barrier layer. Therefore, the load applied to the base material layer at the time of molding can be suppressed and the occurrence of whitening due to resin cracking can be prevented. In addition, since ink enters fine irregularities, the printability of the protective layer surface is improved.

  Further, the resin constituting the protective layer contains an amine as a crosslinking agent, and has an electrolytic solution resistance, alcohol resistance, and heat resistance with respect to the protective layer formed in a matte tone. Thereby, the protective layer is less likely to have a matte appearance with respect to the heat history in the process of laminating the electrolyte solution, the wiping with alcohol, and the packaging material for electrochemical cells, and the reduction in slipperiness is suppressed.

  In the electrochemical cell packaging material having the above-described structure, the present invention is characterized in that a slip agent is contained in the resin constituting the protective layer. According to this configuration, the coefficient of dynamic friction on the surface of the protective layer is reduced, and the slipperiness is further improved.

  The present invention is also characterized in that, in the electrochemical cell packaging material having the above-described structure, a slip film formed of a slip agent is formed on the upper surface of the protective layer. According to this configuration, the coefficient of dynamic friction on the surface of the protective layer is reduced, and the slipperiness is further improved.

  According to the present invention, in the electrochemical cell packaging material configured as described above, the base material layer is formed of a stretched polyamide film. The stretched polyamide film is excellent in stretchability. Thereby, generation | occurrence | production of the whitening by the resin crack of the base material layer at the time of shaping | molding can be prevented.

  The present invention is also characterized in that, in the electrochemical cell packaging material configured as described above, the base material layer comprises a stretched polyester film. The stretched polyester film is excellent in electrolytic solution resistance and hardly corroded with respect to the electrolytic solution that has penetrated to the base material layer. Thereby, generation | occurrence | production of the whitening resulting from corrosion of a base material layer is prevented more.

  According to the present invention, the protective layer disposed in the outermost layer is formed of a resin containing a main agent, a curing agent, and a crosslinking agent containing an amine, so that the protective layer is excellent in electrolytic solution resistance and adheres to the electrolytic solution. On the other hand, the electrolytic solution is prevented from penetrating the protective layer and corroding the base material layer. Thereby, generation | occurrence | production of the whitening resulting from corrosion of a base material layer is prevented. In addition, the protective layer formed of a resin containing an amine as a crosslinking agent is excellent in alcohol resistance and heat resistance. By having alcohol resistance, the surface of the protective layer hardly undergoes deformation or discoloration of the surface of the protective layer with respect to wiping with alcohol. Moreover, by having heat resistance, it is difficult for deformation and discoloration of the protective layer to occur with respect to the thermal history of the lamination process of the packaging material for electrochemical cells.

The perspective view of the lithium ion battery which concerns on embodiment of this invention AA line sectional view in FIG. Schematic sectional view showing a layer structure of a packaging material according to an embodiment of the present invention

  Hereinafter, the packaging material 110 for an electrochemical cell according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a lithium ion battery 121 according to an embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

  The lithium ion battery 121 is configured by housing a lithium ion battery main body 122 containing an electrolytic solution in the package 120. The package 120 includes a storage portion 120a that stores the lithium ion battery main body 122 and a sheet-like lid portion 120b that covers the storage portion 120a.

  The package 120 has a thermal bonding portion 120c at the periphery where the storage portion 120a and the lid portion 120b overlap each other, and the inside is sealed. At this time, the positive electrode tab 123a and the negative electrode tab 123b connected to the lithium ion battery main body 122 extend to the outside while being sandwiched by the storage portion 120a and the lid portion 120b with a tab film (not shown) interposed in the thermal bonding portion 120. ing.

  The lithium ion battery main body 122 is configured by a cell including a positive electrode made of a positive electrode active material and a positive electrode current collector, a negative electrode made of a negative electrode active material and a negative electrode current collector, and an electrolyte filled between the positive electrode and the negative electrode. The The cell is formed by laminating a plurality of positive electrode plates from which a positive electrode current collector extends and negative electrode plates from which a negative electrode current collector extends. A plurality of positive plates and negative plates are alternately stacked via separators. The plurality of stacked positive electrode current collectors and negative electrode current collectors are overlapped and connected to a single positive electrode tab 123a and negative electrode tab 123b, respectively.

  FIG. 3 is a schematic cross-sectional view showing the layer structure of the packaging material 110 that forms the storage portion 120a and the lid portion 120b. The packaging material 110 includes a protective layer 111, a base material layer 112, a barrier layer 114, and a thermal bonding layer 116. It is constructed by stacking sequentially. The base material layer 112 and the barrier layer 114 are bonded via an adhesive layer 113, and the barrier layer 114 and the thermal adhesive layer 116 are bonded via an acid-modified polyolefin layer 115. The both surfaces of the barrier layer 114 are subjected to chemical conversion treatment, and the interlayer adhesion strength between the barrier layer 114 and the acid-modified polyolefin layer 115 and between the barrier layer 114 and the adhesive layer 113 is increased.

  As shown in FIG. 2, the storage portion 120a is manufactured by press-molding a packaging material 110 cut into a rectangular shape. In the molding process, the protective layer 111 side of the packaging material 110 is placed facing the concave female mold, and then cold-cooled to a predetermined molding depth with the male mold from the thermal adhesive layer 116 side. The container 120a is formed by molding. The storage portion 120a and the lid portion 120b are thermally bonded to the opposing thermal adhesive layer 116.

  The base material layer 112 is made of a resin film and imparts high puncture resistance (pinhole resistance), insulation, workability, and the like to the package 120, and has spreadability that can withstand press during embossing. There is a need.

  As the base material layer 112, polyester, polyamide, epoxy, acrylic, fluororesin, polyurethane, silicon resin, phenol, and a mixture or copolymer thereof can be used. Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate. Examples of the polyamide include nylon 6, nylon 6,6, a copolymer of nylon 6 and nylon 6,6, nylon 6,10, polymetaxylylene adipamide (MXD6), and the like. The stretched polyamide film is excellent in stretchability. Thereby, generation | occurrence | production of the whitening by the resin crack of the base material layer 112 at the time of shaping | molding can be prevented. In addition, the stretched polyester film is excellent in resistance to electrolytic solution and hardly corroded with respect to the electrolytic solution that has penetrated to the base material layer 112. Thereby, generation | occurrence | production of the whitening resulting from the corrosion of the base material layer 112 is prevented more.

  Among these, preferably nylon and polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched polyester. By performing the biaxial stretching treatment, the resin film is oriented and crystallized, and the heat resistance of the base material layer 112 can be improved.

  The base material layer 112 can be laminated with films of different materials in order to improve pinhole resistance and insulation when used as a battery package. Specifically, the multilayer structure which laminated | stacked polyester and nylon and the multilayer structure which laminated | stacked biaxially-stretched polyester and biaxially-stretched nylon are mentioned. When the base material layer 112 has a multilayer structure, films of different materials may be laminated via an adhesive, and the type and amount of the adhesive used may be the same as those of the adhesive layer 113 described later. it can. The thickness of the base material layer 112 is, for example, 10 to 50 μm, preferably 15 to 30 μm.

  The protective layer 111 is disposed on the outermost layer and prevents the electrolyte solution from adhering to the outer surface of the battery packaging material 110 to corrode and whiten the base material layer 112. The protective layer 111 is formed of a resin in which a main agent, a curing agent, a crosslinking agent, and a matting agent are mixed.

  The main agent is a resin which is a main component of the resin constituting the protective layer 111, and urethane such as polyester and polyether, polyester urethane, epoxy, acrylic, phenol, cellulose, polyamide, polyamideimide, and polyimide are used. A plurality of these resins may be mixed.

  The curing agent is a resin that reacts with the main agent to start, accelerate, or adjust the curing of the resin constituting the protective layer 111, and an isocyanate resin is used. Tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI) can be used as the isocyanate resin. A plurality of these resins may be mixed.

  The crosslinking agent is a resin that links the polymers of the resin constituting the protective layer 111 and changes the protective layer 111 physically or chemically, and an amine is used. As the amine, melamine, polyaminoamide, spiro ring-containing guanamine, benzoguanamine and the like are used. These amines increase the compatibility with the resin constituting the protective layer 111. In addition, in order to improve the miscibility with the solvent for solubilization when forming the protective layer 111 in the manufacturing method to be performed later, the amine is previously methylated, butylated, a mixture of methylated and butylated It is preferable to use it in the etherified state. Thereby, a stable cross-linked product can be formed and the performance as the protective layer 111 is improved. Further, it is more preferable to add a reaction accelerator, a homogeneous catalyst, or a heterogeneous catalyst in order to promote the reaction at a low temperature. The reaction accelerator is made of an organic substance or an inorganic substance, the homogeneous catalyst is made of an acid, a basic catalyst, a metal complex, or the like, and the heterogeneous catalyst is made of platinum, palladium, iron oxide, or the like.

  Moreover, by using an amine as a crosslinking agent, the electrolytic solution resistance of the protective layer 111 is improved. Thereby, it is possible to prevent the electrolytic solution from penetrating the protective layer 111 and corrode the base material layer 112, and to prevent whitening due to the corrosion of the base material layer 112. Further, the electrolytic resistance of the protective layer 111 is unlikely to decrease even in a region where the base material layer 112 is stretched during press molding. Thereby, whitening due to corrosion of the base material layer 112 can be prevented even when the electrolytic solution adheres to the corner portion of the storage portion 120a. The electrolytic solution resistance of the protective layer 111 means that the electrolytic solution adheres to the protective layer 111 and is allowed to stand at room temperature for about 1 hour, and then the substrate layer 112 is not whitened when the electrolytic solution is wiped off. Liquidity is required.

  In addition, the protective layer 111 formed of a resin containing an amine as a crosslinking agent is excellent in alcohol resistance and heat resistance. By improving the alcohol resistance of the protective layer 111, even if the surface of the protective layer 111 is wiped with a cloth soaked with alcohol such as ethanol, the protective layer 111 is hardly discolored and deformed. Further, by improving the heat resistance of the protective layer 111, the protective layer 111 is less likely to be deformed and discolored with respect to the thermal history of the lamination process of the packaging material 110 for electrochemical cells. In addition, the heat history concerning the lamination | stacking process of the packaging material 110 for electrochemical cells is about 60 degreeC of room temperature performed after pressurizing and heating the base material layer 112 and the barrier layer 114 through the dry-laminate adhesive mentioned later Examples include an aging treatment for 5 days, and a heat treatment after leaving the acid-modified polyolefin layer 115 and the thermal adhesive layer 116 on the barrier layer 114 for 5 seconds at a room temperature of 190 ° C.

  In addition, by using benzoguanamine or melamine or a mixture of benzoguanamine and melamine as a crosslinking agent, the electrolytic solution resistance, alcohol resistance, and heat resistance are further improved.

  The matting agent forms fine irregularities on the surface of the protective layer 111, so that the appearance of the electrochemical cell packaging material 110 is matte (matte). Further, due to the fine unevenness, the dynamic friction coefficient on the surface of the protective layer 111 is lowered and the slipperiness is improved. Thereby, for example, when the packaging material 110 for electrochemical cells is press-molded using a molding die, the base material layer 112 is stretched while following the barrier layer 114 against the deformation of the barrier layer 114. Therefore, the load applied to the base material layer 112 at the time of molding can be suppressed, and the occurrence of whitening due to resin cracking can be prevented.

  In addition, the printability is improved because the ink enters fine irregularities. In addition, the fine unevenness | corrugation formed in the protective layer 111 surface can be quantified with the GU value which evaluates the glossiness of the protective layer 111. That is, when the GU value is high, the degree of matting (matte degree) on the surface of the protective layer 111 is high, and the unevenness on the surface of the protective layer 111 becomes rough. For this reason, it is preferable to set the GU value to 10 or less in consideration of the slipperiness and printability of the surface of the protective layer 111. Further, the GU value of the protective layer 111 can be adjusted by the particle size and the addition amount of the matting agent added to the resin constituting the protective layer 111.

  As the matting agent, fine particles having a particle size of 0.5 nm to 5 μm are used, and examples of the shape include a spherical shape, a fiber shape, a plate shape, an indeterminate shape, and a balloon shape. Moreover, you may add combining these shapes. Examples of the material for the matting agent include metals, metal oxides, inorganic substances, and organic substances.

Specifically, the generic names are talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, oxidation Neodymium, 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, cross-linked acrylic, cross-linked styrene, cross-linked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, cross-linked acrylic such as styrene and polymethyl methacrylate, ben Amino resins comprising a guanamine or melamine and formaldehyde condensate, and a fluorine resin such as tetrafluoroethylene resin.
Etc.

  The surface of the matting agent particles may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment. As the matting agent, silica, barium sulfate, and titanium oxide that can be matted in a small amount because of favorable and stable dispersibility and price are particularly preferable.

  The addition amount of the matting agent is preferably 0.5 to 30% by weight when the total weight of the main agent, the curing agent and the crosslinking agent constituting the protective layer 111 is 100. In addition, since the protective layer 111 to which the matting agent is added contains an amine as a cross-linking agent, the protective layer 111 formed in a matte manner has resistance to electrolyte, alcohol, and heat. Thereby, the protective layer 111 is hardly deteriorated in matte appearance with respect to the heat history in the stacking process of the adhesion of the electrolytic solution, the wiping with alcohol, and the packaging material 110 for the electrochemical cell, and the decrease in the slipping property is suppressed. Therefore, after printing on the surface of the protective layer 111 with oil-based ink, the printing can be easily wiped off with alcohol without deteriorating the matte tone of the protective layer 111.

  The slip agent improves the slipperiness of the surface of the protective layer 111. Slip agents include fatty acid amide, metal soap, hydrophilic silicone, silicone grafted acrylic, silicone grafted epoxy, silicone grafted polyether, silicone grafted polyester, block silicone acrylic copolymer, polyglycerin modified Fluorine resins such as silicone, polyglycerol-modified silicone, paraffin, and ethylene tetrafluoride can be used. The slip agent may be contained in the resin constituting the protective layer 111 or may be applied to the upper surface of the protective layer 111 to form a slip film (not shown). The slip agent has printability for water-based ink and oil-based ink. Also, the ink fixing property is good, and even if the ink is wiped after printing, the ink cannot be wiped off.

  The protective layer 111 may be formed by selecting the resin constituting the protective layer 111 by selecting a known coating method such as a bar coating method, a roll coating method, a gravure coating method, a dipping method, or a die coating. The coating method is most preferable because of excellent productivity. Moreover, after coating the base material layer 112 with the protective layer 111, it is preferable to age at room temperature of 40 to 100 degreeC for 3 to 7 days, and to post-heat at 170 to 250 degreeC for about 3 second. As a result, the resistance to electrolyte can be maximized and maintained for a long time. Therefore, the baking process is not required for forming the protective layer 111, and the protective layer 111 can be formed by curing only by low-temperature aging or by low-temperature aging and post-heating. For this reason, it can prevent that the base material layer 112 shrink | contracts or expands, or melts | dissolves by heat | fever history in the lamination process of the protective layer 111.

  The barrier layer 114 is made of a metal foil, and in addition to improving the strength of the electrochemical cell packaging material 110, it prevents water vapor, oxygen, light, and the like from entering the electrochemical cell. Specific examples of the metal foil that forms the barrier layer 114 include aluminum, stainless steel, and titanium. Among these, aluminum is preferably used.

  Further, soft aluminum, for example, annealed aluminum (JIS A8021P-O) or (JIS A8079P-O) is particularly preferable. These aluminums can further prevent wrinkles and pinholes generated during the production of the electrochemical cell packaging material 110. Moreover, about the thickness of metal foil, 10-200 micrometers, for example, Preferably 20-100 micrometers is used. Thereby, the pinhole and processability (pouching, embossing formability) of the barrier layer 114 alone can be stabilized and pinhole resistance can be provided.

  The barrier layer 114 is preferably subjected to chemical conversion treatment at least on the surface in contact with the acid-modified polyolefin layer 115 in order to stabilize adhesion and prevent corrosion. It is more preferable that the both surfaces of the barrier layer 114 are subjected to chemical conversion treatment. The chemical conversion treatment is a treatment for forming an acid resistant film on the surface of the barrier layer 114. Examples of the chemical conversion treatment include chromic acid chromate treatment, phosphoric acid chromate treatment, and chromate treatment using an aminated phenol polymer. For the chromate chromate treatment, 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 is used. In addition, phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate and polyphosphoric acid are used for the phosphoric acid chromate treatment.

  For the chromate treatment using the aminated phenol polymer, an aminated phenol polymer comprising repeating units represented by the following general formulas (1) to (4) is used.

  In formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R1 and R2 represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. R1 and R2 may be the same.

  In the formulas (1) to (4), examples of the alkyl group represented by X, R1, and R2 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. C1-C4 linear or branched alkyl groups, such as group, are mentioned.

  Examples of the hydroxyalkyl group represented by X, R1, and R2 include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, and a 3-hydroxypropyl group. Group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group and the like, and a linear or branched alkyl group having 1 to 4 carbon atoms substituted with one hydroxy group Is mentioned.

  The number average molecular weight of the aminated phenol polymer comprising the repeating units represented by the chemical formulas (1) to (4) is, for example, about 500 to about 1,000,000, preferably about 1,000 to about 20,000.

  Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 114, a surface in which the metal oxide or barium sulfate fine particles are dispersed in phosphoric acid is coated and subjected to baking treatment at 150 ° C. or higher. And a method of forming a corrosion-resistant treatment layer. At this time, examples of the metal oxide include aluminum oxide, titanium oxide, cerium oxide, and tin oxide.

  Moreover, you may form the resin layer which bridge | crosslinked the cationic polymer with the crosslinking agent on the corrosion-resistant process layer. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin obtained by grafting a primary amine on an acrylic main skeleton, polyallylamine or a derivative thereof, Examples include aminophenol.

  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 combining a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer is more preferable.

The amount of the acid-resistant film formed on the surface of the barrier layer 114 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, for example. 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, preferably It is desirable to contain about 1.0 to about 40 mg and an aminated phenol polymer in a proportion of about 1 to about 200 mg, preferably about 5.0 to 150 mg.

  In the chemical conversion treatment, after the solution containing the compound used for forming the acid-resistant film is applied to the surface of the metal layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, the temperature of the barrier layer 114 is increased. It is carried out by heating to about 70 to 200 ° C. In addition, before the chemical conversion treatment is performed on the barrier layer 114, the barrier layer 114 may be previously subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing process in this way, it is possible to perform the chemical conversion process on the surface of the barrier layer 114 more efficiently.

  The thermal adhesive layer 116 is disposed on the innermost layer of the packaging material 110 and is made of a thermal adhesive resin that melts by heat and fuses the opposing packaging materials 110 to each other. The resin type differs depending on whether or not a tab film is interposed between the thermal adhesive layer 116 and the positive electrode tab 123a or the negative electrode tab 123b. When a tab film is interposed, a film made of a propylene resin alone or a mixture may be used. When no tab film is interposed, a film made of an acid-modified olefin resin graft-modified with an unsaturated carboxylic acid may be used.

  Polypropylene is preferably used as the thermal adhesive layer 116, but a single layer or a single layer or a multilayer of linear low density polyethylene or medium density polyethylene, or a blend of linear low density polyethylene or medium density polyethylene, or It can also be used as a multilayer film.

  For each type of polypropylene, that is, random propylene, homopropylene, block propylene, and linear low density polyethylene, medium density polyethylene, low crystalline ethylene-butene copolymer, low crystalline propylene-butene copolymer, A terpolymer composed of a three-component copolymer of ethylene, butene, and propylene, silica, zeolite, an antiblocking agent (AB agent) such as acrylic resin beads, a fatty acid amide slip agent, and the like may be added.

  The acid-modified polyolefin layer 115 is a resin layer that stably bonds the barrier layer 114 and the thermal adhesive layer 116, and acid-modified polypropylene is preferably used. In addition, the acid-modified polyolefin layer 115 needs to be appropriately selected and used depending on the resin type used for the thermal bonding layer 116. For this reason, when using an acid-modified polyolefin resin other than acid-modified polypropylene, a polyolefin resin graft-modified with an unsaturated carboxylic acid, a copolymer of ethylene or propylene and acrylic acid, or methacrylic acid, or a metal-crosslinked polyolefin resin If necessary, a butene component, an ethylene-propylene-butene copolymer, an amorphous ethylene-propylene copolymer, a propylene-α-olefin copolymer, or the like may be added by 5% or more.

When using acid-modified polypropylene,
(1) A homotype having a bigat softening point of 115 ° C or higher and a melting point of 150 ° C or higher (2) A copolymer of ethylene-propylene having a bigat softening point of 105 ° C or higher and a melting point of 130 ° C or higher (random copolymer type)
(3) A simple substance or a blended product obtained by acid-modified polymerization using an unsaturated carboxylic acid having a melting point of 110 ° C. or higher can be used.

  The adhesive layer 113 is a resin layer that firmly bonds the base material layer 112 and the barrier layer 114. Such interlayer adhesion can be performed by a dry lamination method, an extrusion lamination method, a coextrusion lamination method, a thermal lamination method, or the like. Alternatively, the base material layer 112 may be laminated by melting and extruding a resin constituting the base material layer 112 on the upper surface of the barrier layer 114 without providing the adhesive layer 113.

  When laminating by the dry laminating method, polyester, polyethyleneimine, polyether, cyanoacrylate, urethane, organic titanium, polyetherurethane, epoxy, polyesterurethane, imide, isocyanate Various adhesives based on polyolefin, polyolefin, and silicone can be used.

  The adhesive layer 113 is a resin layer that firmly bonds the base material layer 112 and the barrier layer 114. The adhesion mechanism used for the adhesive layer 113 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, a UV curing type, a thermal crosslinking type, and the like.

  Adhesive component polyester resin, polyether adhesive, polyurethane adhesive, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose adhesive, (meth) Acrylic resins, polyimide resins, amino resins, rubbers, and silicone resins can be used.

  Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester.

  Examples of the polyamide-based resin include nylon 6, nylon 66, nylon 12, and copolymerized polyamide. Examples of the polyolefin resin include polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin. Examples of amino resins include urea resins and melamine resins. Examples of the rubber include chloroprene rubber, nitrile rubber, and styrene-butadiene rubber.

  These adhesive components may be used alone. Moreover, you may use combining 2 or more types. The combination mode of two or more kinds of adhesive components is not particularly limited. For example, a mixed resin of polyamide and carboxylic acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, polyamide and polyester, polyester and carboxylic acid-modified polyolefin, And a mixed resin of polyester and metal-modified polyolefin. Among these, a polyurethane two-component curable adhesive is particularly preferable. Moreover, the blend resin of polyamide, polyester, or these, and carboxylic acid modification polyolefin is also mentioned.

  The thickness of the adhesive layer 113 is preferably 2 to 50 μm. The adhesive layer 113 can be formed by a general method such as a gravure coating method, a roll coating method, or a melt extrusion method. As a lamination method, lamination can be performed by a general dry lamination method, thermal lamination method, co-extrusion lamination method, sand lamination method, and combinations thereof. Furthermore, you may use for heat processing, such as a hot roll contact type, a hot air type, a near or far-infrared type. Examples of such heat treatment conditions include 150 to 210 ° C. and 1 to 10 seconds.

  According to this embodiment, by providing the protective layer 111 composed of a resin composed of a main agent, a curing agent, and an amine-containing crosslinking agent on the outer surface of the base material layer 112, the protective layer 111 has excellent resistance to electrolytic solution. The electrolytic solution penetrates the protective layer 111 and prevents the base material layer 112 from being corroded against the adhesion of the electrolytic solution. Thereby, generation | occurrence | production of the whitening resulting from the corrosion of the base material layer 112 is prevented. Further, the electrolytic resistance of the protective layer 111 is unlikely to decrease even in a region where the base material layer 112 is stretched during press molding. Thereby, whitening due to corrosion of the base material layer 112 can be prevented even when the electrolytic solution adheres to the corner portion of the storage portion 120a. In addition, the protective layer 111 formed of a resin containing an amine as a crosslinking agent is excellent in alcohol resistance and heat resistance. By having alcohol resistance, the surface of the protective layer 111 is less likely to be deformed or discolored when the surface of the protective layer 111 is wiped off with alcohol. Moreover, since it has heat resistance, the deformation and discoloration of the protective layer 111 are unlikely to occur with respect to the thermal history of the lamination process of the packaging material 110 for electrochemical cells.

  Moreover, the electrolyte solution resistance, alcohol resistance, and heat resistance of the protective layer 111 are further improved by making the amine contained in the cross-linking agent into benguanamine, melamine, or a mixture of benzoguanamine and melamine.

  Further, when the matting agent is included in the protective layer 111, fine irregularities are formed on the surface of the protective layer 111, and the appearance of the electrochemical cell packaging material 110 is formed in a matte (matte) tone. Further, due to the fine unevenness, the dynamic friction coefficient on the surface of the protective layer 111 is lowered and the slipperiness is improved. Thereby, for example, when the packaging material 110 for electrochemical cells is press-molded using a molding die, the base material layer 112 is stretched while following the barrier layer 114 against the deformation of the barrier layer 114. Therefore, the load applied to the base material layer 112 at the time of molding can be suppressed, and the occurrence of whitening due to resin cracking can be prevented. In addition, since ink enters fine irregularities, the printability of the surface of the protective layer 111 is improved. Thereby, for example, printing can be performed on the surface of the protective layer 111 with water-based ink.

  Further, the protective layer 111 to which the matting agent is added contains an amine as a cross-linking agent, and the protective layer 111 formed in a matte tone has an electrolytic solution resistance, an alcohol resistance, and a heat resistance. Thereby, the protective layer 111 is hardly deteriorated in matte appearance with respect to the heat history in the stacking process of the adhesion of the electrolytic solution, the wiping with alcohol, and the packaging material 110 for the electrochemical cell, and the decrease in the slipping property is suppressed. Therefore, after printing on the surface of the protective layer 111 with oil-based ink or alcoholic ink, the print can be wiped off with alcohol without deteriorating the matte tone of the protective layer 111.

  Further, when the slip agent is contained in the resin constituting the protective layer 111, the dynamic friction coefficient on the surface of the protective layer 112 is further reduced, and whitening caused by resin cracking during molding can be further prevented. The same effect can be obtained by forming a slip film made of a slip agent on the upper surface of the protective layer 111.

  Moreover, since the stretched polyamide film is excellent in stretchability by constituting the substrate layer 112 with a stretched polyamide film, it is possible to prevent the occurrence of whitening due to resin cracking of the substrate layer 112 during molding. Moreover, by comprising the base material layer 112 with a stretched polyester film, the stretched polyethylene tellurium film is excellent in electrolytic solution resistance and hardly corrodes with respect to the electrolyte solution that has penetrated to the base material layer 112. Thereby, generation | occurrence | production of the whitening resulting from the corrosion of the base material layer 112 is prevented more.

  In the present embodiment, different layers may be interposed between the layers. Moreover, although the lithium ion battery 121 is described, an electrochemical cell body other than the lithium ion battery body 122 may be packaged with a package 120 made of the packaging material 110 to produce an electric cell other than the lithium ion battery 121. .

  For example, the electrochemical cell includes a nickel metal hydride battery, a nickel cadmium battery, a lithium metal primary battery or secondary battery, a chemical battery such as a lithium polymer battery, an electric double layer capacitor, a capacitor, and an electrolytic capacitor in addition to a lithium ion battery. Here, the electrochemical cell body is a positive electrode composed of a positive electrode active material and a positive electrode current collector before enclosing packaging material, a negative electrode composed of a negative electrode active material and a negative electrode current collector, and an electrolyte filled between the positive electrode and the negative electrode. And all electric device elements that generate electric energy, such as a cell (power storage unit) including electrode terminals connected to a positive electrode and a negative electrode in the cell.

  Next, the action and effect of the present invention will be specifically described using examples and comparative examples. In this experiment, the protective layer 111 is formed on the upper surface of the base material layer 112 constituting the packaging material 110 for an electrochemical cell, and the glossiness and appearance failure due to resin cracking (whitening due to fine cracks) during molding (stretching) are performed. The presence / absence, the presence / absence of whitening of the base material layer 112 when the electrolytic solution was dropped, the slipperiness, heat resistance, printability, and alcohol resistance of the protective layer 111 were evaluated.

[Preparation of packaging materials for electrochemical cells]
The packaging material 110 for an electrochemical cell according to Example 1 is subjected to chemical conversion treatment on both surfaces of aluminum (thickness 40 μm) which is a barrier layer 114, and a biaxially stretched nylon film which is a base material layer 112 on one chemical conversion treatment surface. (Pressure 25 μm) is pressure-heat-bonded by a dry laminating method through a two-component urethane adhesive (thickness 4 μm) of a polyester-based main agent and an isocyanic curing agent that becomes the adhesive layer 113, and then at 60 ° C. Aging was performed for 24 hours. A protective layer 111 is formed in advance on the upper surface of the stretched nylon film by applying a mixed resin containing a main agent, a curing agent, and a crosslinking agent.

  Next, after the maleic acid-modified polypropylene (thickness 25 μm) and random polypropylene (thickness 25 μm) are laminated on the other chemical conversion treated surface by a melt coextrusion method, the acid-modified polyolefin layer 115 and the thermal adhesive layer 116 are formed. Post-heating was performed at 190 ° C. for 5 seconds.

In addition, the chemical conversion treatment of aluminum as the barrier layer 114 is performed by applying a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid by a roll coating method before laminating the base material layer 112 and the thermal bonding layer 116, and coating temperature Was baked and processed under the condition of 180 ° C. or higher. The application amount of chromium was 10 mg / m ² (dry weight).

  In addition, acrylic was used as a main resin for the mixed resin constituting the protective layer 111, methylated benzoguanamine was used as a crosslinking agent, and isocyanate resin was used as a curing agent. The isocyanate resin was composed of tolylene diisocyanate (hereinafter abbreviated as TDI) and hexamethylene diisocyanate (hereinafter abbreviated as HDI). Note that the matting agent and the slip agent were not added to the protective layer 111 according to Example 1. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 2.5 for the curing agent. The weight ratio of the curing agent was set to 2 for TDI and 0.5 for HDI.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . Further, the packaging material 110 for an electrochemical cell according to Example 1 was subjected to a post-heating treatment at 190 ° C. for 5 seconds after all the above layers were laminated, thereby improving the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material 110 according to the second embodiment has the same layer configuration except for the electrochemical cell packaging material 110 according to the first embodiment and the protective layer 111. In the packaging material 110 for an electrochemical cell according to Example 2, acrylic was used as a main resin for the mixed resin constituting the protective layer 111, methylated benzoguanamine was used as a crosslinking agent, and isocyanate resin was used as a curing agent. The isocyanate resin was composed of TDI and isophorone diisocyanate (hereinafter abbreviated as IPDI). Further, a matting agent was added to the mixed resin constituting the protective layer 111, and no slip agent was added. Silica having a particle size of 0.1 μm was used as the matting agent. The weight ratio of the mixed resin constituting the protective layer 111 was 80 for the main agent, 20 for the crosslinking agent, and 2.5 for the curing agent. The weight ratio of the matting agent was 10 when the main agent, the crosslinking agent, and the curing agent were 100. The weight ratio of the curing agent was 2 for TDI and 0.5 for IPDI.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . Moreover, the packaging material 110 for electrochemical cells which concerns on Example 2 did not perform the post-heating process after lamination | stacking.

  The electrochemical cell packaging material 110 according to Example 3 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the packaging material 110 for an electrochemical cell according to Example 3, acrylic was used as the main resin for the mixed resin constituting the protective layer 111, methylated benzoguanamine was used as the crosslinking agent, and isocyanate resin was used as the curing agent. The isocyanate resin was composed of TDI, HDI, and IPDI. Further, a slip agent was added to the mixed resin constituting the protective layer 111 without adding a matting agent. Calcium stearate was used as the slip agent. Further, the weight ratio of the mixed resin constituting the protective layer 111 was 85 for the main agent, 15 for the crosslinking agent, and 3 for the curing agent. Further, when the main agent, the crosslinking agent and the curing agent were 100, the weight ratio of the slip agent was 0.5. Further, the weight ratio of the curing agent was set to 2 for TDI, 0.5 for HDI, and 0.5 for IPDI.

  The electrochemical cell packaging material 110 according to Example 4 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the packaging material 110 for an electrochemical cell according to Example 4, acrylic was used as a main resin for the mixed resin constituting the protective layer 111, methylated benzoguanamine was used as a crosslinking agent, and isocyanate resin was used as a curing agent. The isocyanate resin was composed of TDI, HDI, and IPDI. Further, a matting agent was added to the mixed resin constituting the protective layer 111, and no slip agent was added. The slip agent was coated on the upper surface of the protective layer 111 to form a slip film. Calcium stearate was used as the slip agent. As the matting agent, silica having a particle size of 0.1 μm and silica having a particle size of 1.0 μm were used. At this time, the mixing ratio of silica having a particle diameter of 0.1 μm and silica having a particle diameter of 1 μm was 4: 1. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 3 for the curing agent. The weight ratio of the matting agent was 8 when the main agent, the crosslinking agent and the curing agent were 100. Further, the weight ratio of the curing agent was set to 2 for TDI, 0.5 for HDI, and 0.5 for IPDI.

  The electrochemical cell packaging material 110 according to Example 5 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the packaging material 110 for an electrochemical cell according to Example 5, acrylic was used as the main resin for the mixed resin constituting the protective layer 111, methylated benzogamine as the crosslinking agent, and isocyanate resin as the curing agent. The isocyanate resin was composed of TDI and HDI. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. Silica having a particle size of 0.1 μm was used as the matting agent. Hydrophilic silicone graft acrylic was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 2.5 for the curing agent. The weight ratio of the matting agent was 5 when the main agent, the crosslinking agent and the curing agent were 100. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 0.5. The weight ratio of the curing agent was set to 2 for TDI and 0.5 for HDI.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the electrochemical cell packaging material 110 according to Example 5 was formed by laminating all the above layers and then performing a post-heating treatment at 190 ° C. for 5 seconds to improve the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material 110 according to Example 6 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the electrochemical cell packaging material 110 according to Example 6, polyester urethane and acrylic were used as the main components for the mixed resin constituting the protective layer 111, mixed etherified benzogamine as the crosslinking agent, and isocyanate resin as the curing agent. The isocyanate resin was composed of TDI and HDI. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. Silica having a particle size of 0.1 μm was used as the matting agent. Bisoleic acid amide was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 95 for the main agent, 5 for the crosslinking agent, and 2.5 for the curing agent. Further, when the total weight of the main agent, the crosslinking agent and the curing agent was 100, the weight ratio of the matting agent was 10. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 5. The weight ratio of the main agent was 60 for polyester urethane and 35 for acrylic. The weight ratio of the curing agent was set to 2 for TDI and 0.5 for HDI.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the electrochemical cell packaging material 110 according to Example 6 was subjected to a post-heating treatment at 190 ° C. for 5 seconds after all the above layers were laminated, thereby improving the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material 110 according to Example 7 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the electrochemical cell packaging material 110 according to Example 7, polyester urethane and acrylic were used as the main components for the mixed resin constituting the protective layer 111, methylated benzoguanamine was used as the crosslinking agent, and isocyanate resin was used as the curing agent. The isocyanate resin was composed of diphenylmethane diisocyanate (hereinafter abbreviated as MDI) alone. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. Silica having a particle size of 1 μm was used as the matting agent. A hydrophilic silicone graft ester was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 3 for the curing agent. The weight ratio of the matting agent was 5 when the total weight of the main agent, the crosslinking agent and the curing agent was 100. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 2. The weight ratio of the main agent was 40 for polyester urethane and 50 for acrylic.

  In addition, the packaging material 110 for an electrochemical cell according to Example 7 was formed by laminating all the above layers, and then coating the mixed resin constituting the protective layer 111 on the upper surface of the biaxially stretched nylon film to a thickness of 3 μm. A protective layer 111 was formed by curing by aging treatment at 60 ° C. for 5 days. Thereafter, a post-heating treatment was performed at 190 ° C. for 5 seconds to improve the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116.

  The electrochemical cell packaging material 110 according to Example 8 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the electrochemical cell packaging material 110 according to Example 8, acrylic and epoxy were used as the main components for the mixed resin constituting the protective layer, methylated benzoguanamine was used as the crosslinking agent, and isocyanate resin was used as the curing agent. The isocyanate resin was composed of IPDI and TDI. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. As the matting agent, silica having a particle size of 0.1 μm and silica having a particle size of 1.0 μm were used. At this time, the mixing ratio of silica having a particle diameter of 0.1 μm and silica having a particle diameter of 1 μm was 4: 1. Calcium stearate was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 3 for the curing agent. Further, when the total weight of the main agent, the crosslinking agent and the curing agent was 100, the weight ratio of the matting agent was 8. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 2. The weight ratio of the main agent was 70 for acrylic and 20 for epoxy. The weight ratio of the curing agent was 2 for IPDI and 1 for TDI.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the packaging material 110 for an electrochemical cell according to Example 8 was formed by laminating all the above layers, and then subjected to a post-heating treatment at 190 ° C. for 5 seconds to improve the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material 110 according to Example 9 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the electrochemical cell packaging material 110 according to Example 9, epoxy and polyether polyurethane were used as the main components in the mixed resin constituting the protective layer, methylated melamine was used as the crosslinking agent, and isocyanate resin was used as the curing agent. In addition, the isocyanate resin comprised TDI independently. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. Silica having a particle size of 0.02 μm was used as the matting agent. Paraffin was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 80 for the main agent, 20 for the crosslinking agent, and 3 for the curing agent. The weight ratio of the matting agent was 20 when the total weight of the main agent, the crosslinking agent and the curing agent was 100. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 5. The weight ratio of the main agent was 60 for epoxy and 20 for polyether polyurethane.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the packaging material 110 for an electrochemical cell according to Example 9 was formed by laminating all the above layers, and then subjected to a post-heating treatment at 190 ° C. for 5 seconds to improve the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material 110 according to Example 10 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the electrochemical cell packaging material 110 according to Example 10, acrylic and polyester ether urethane were used as the main components for the mixed resin constituting the protective layer, aminoamide was used as the crosslinking agent, and isocyanate resin was used as the curing agent. The isocyanate resin was composed of HDI alone. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer 111. Barium sulfate having a particle size of 0.1 μm was used as the matting agent. Polyglycerol silicone was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 90 for the main agent, 10 for the crosslinking agent, and 3 for the curing agent. The weight ratio of the matting agent was 20 when the total weight of the main agent, the crosslinking agent and the curing agent was 100. Further, when the total weight of the main agent, the crosslinking agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 5. The weight ratio of the main agent was 50 for acrylic and 40 for polyester ether urethane.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the packaging material 110 for an electrochemical cell according to Example 10 was formed by laminating all the above layers and then performing a post-heating treatment at 190 ° C. for 5 seconds to improve the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

  The electrochemical cell packaging material according to Example 11 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. The packaging material for an electrochemical cell according to Example 11 used an epoxy as a main component and a benzoguanamine as a cross-linking agent for the mixed resin constituting the protective layer. A curing agent was not added. It was. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer. Silica having a particle size of 0.1 μm was used as the matting agent. Bisoleic acid amide was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer 111 was 80 for the main agent and 20 for the cross-linking agent. Further, when the total weight of the main agent and the crosslinking agent was 100, the weight ratio of the matting agent was 10. Further, when the total weight of the main agent, the crosslinking agent and the matting agent was 100, the weight ratio of the slip agent was 5.

  Moreover, the electrochemical cell packaging material 110 according to Example 11 was formed by laminating all the above layers, and then coating the mixed resin constituting the protective layer 111 on the upper surface of the biaxially stretched nylon film to a thickness of 3 μm. The protective layer 111 was formed by performing a heat treatment at 200 ° C. for 30 seconds to be cured.

[Comparative Example 1]
The electrochemical cell packaging material according to Example 1 that did not have the protective layer 111 was used as the electrochemical cell packaging material according to Comparative Example 1.

[Comparative Example 2]
The electrochemical cell packaging material according to Comparative Example 2 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. In the packaging material for electrochemical cells according to Comparative Example 2, polyester urethane was used as a main component and TDI was used as a curing agent for the mixed resin constituting the protective layer. In addition, the crosslinking agent was not added. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer. Silica having a particle size of 0.1 μm was used as the matting agent. Bistearic acid amide was used as the slip agent. The weight ratio of the mixed resin constituting the protective layer was 100 for the main agent and 3 for the curing agent. Further, when the total weight of the main agent and the curing agent was 100, the weight ratio of the matting agent was 10. Further, when the total weight of the main agent, the curing agent and the matting agent was 100, the weight ratio of the slip agent was 5.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the electrochemical cell packaging material 110 according to Comparative Example 2 was subjected to a post-heating treatment at 190 ° C. for 5 seconds after all the above layers were laminated, thereby improving the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

[Comparative Example 3]
The electrochemical cell packaging material according to Comparative Example 3 has the same layer configuration except for the electrochemical cell packaging material 110 according to Example 1 and the protective layer 111. The packaging material for an electrochemical cell according to Comparative Example 3 used acrylic as a main component in the mixed resin constituting the protective layer. In addition, a crosslinking agent and a curing agent were not added. Further, a matting agent and a slip agent were added to the mixed resin constituting the protective layer. Silica having a particle size of 0.1 μm was used as the matting agent. Silicone oil was used as the slip agent. When the main agent is 100, the weight ratio of the matting agent is 10. Further, when the total weight of the main agent and the matting agent was 100, the weight ratio of the slip agent was 1.

  In addition, the protective layer 111 was formed by coating the upper surface of the biaxially stretched nylon film before bonding the mixed resin to aluminum so as to have a thickness of 3 μm, and then performing an aging treatment at 60 ° C. for 5 days to cure. . In addition, the electrochemical cell packaging material 110 according to Comparative Example 3 was subjected to a post-heating treatment at 190 ° C. for 5 seconds after all the above layers were laminated, thereby improving the interlayer adhesive strength between the barrier layer 114 and the thermal adhesive layer 116. It was.

[Glossiness evaluation]
The glossiness is measured by a gloss meter (manufactured by Konica Minolta Co., Ltd.) indicating the degree of gloss on the surface of the base material layer 112 side of the packaging materials according to Examples 1 to 11 and Comparative Examples 1 to 3. did. The results are shown in Table 1.

[Evaluation of formability]
The evaluation of the resistance to electrolyte solution was performed by cutting the packaging materials according to Examples 1 to 11 and Comparative Examples 1 to 80 mm × 120 mm, and then molding metal mold (female mold) having a depth of 6 mm and a diameter of 35 mm × 50 mm. And cold molding to a depth of 6.0 mm at 0.1 MPa using a corresponding molding die (male type). Next, it was visually observed whether or not whitening due to fine cracks caused by resin cracks at the time of molding occurred on the bottom surface and corner portions molded on the surface of the base material layer side of the packaging material. The results are shown in Table 1.

[Evaluation of electrolyte resistance]
The evaluation of the resistance to electrolyte solution was performed by cutting the packaging materials according to Examples 1 to 11 and Comparative Examples 1 to 80 mm × 120 mm, and then molding metal mold (female mold) having a depth of 6 mm and a diameter of 35 mm × 50 mm. And cold molding to a depth of 6.0 mm at 0.1 MPa using a corresponding molding die (male type). Next, an electrolyte solution (a mixed solution in which ethylene carbonate, diethyl carbonate, and dimethyl carbonate are mixed at a volume ratio of 1: 1: 1 to the bottom surface and the corner portion formed on the surface of the base material layer side of the packaging material is 1M. 0.1 g of LiPF ₆ ) was dropped and left at room temperature of 25 ° C. for 1 hour, and then the electrolyte was wiped off with waste cloth to visually check whether or not whitening due to corrosion occurred in the base material layer of the packaging material. Observed. The results are shown in Table 1.

  As shown in Table 1, the packaging materials according to Examples 2, 4 to 10 had a glossiness of 6.0 or less, and the protective layer surface was formed in a matte tone. In the packaging materials according to Examples 1 to 11, whitening due to fine cracks due to resin cracks during press molding was not observed (◯). In addition, no whitening due to corrosion of the base material layer was observed during the dropping of the electrolytic solution (◯). On the other hand, in the packaging materials according to Comparative Examples 2 and 3, the matte tone formed on the surface of the base material layer in the corner portion after press molding was thinned (×). Further, in the packaging materials according to Comparative Examples 1 to 3, whitening due to corrosion of the base material layer was observed on the bottom surface and the corner portion when the electrolytic solution was dropped (×).

[Evaluation of slipperiness]
The evaluation of slipperiness is based on the friction coefficient (manufactured by Shinto Chemical Co., Ltd.) using the friction coefficient (manufactured by Shinto Chemical Co., Ltd.) as the static friction coefficient on the surface of the packaging material according to Examples 1 to 11 and Comparative Examples 1 to 3 at a pulling speed of 100 mm / sec. It was measured. The results are shown in Table 2.

[Evaluation of heat resistance]
For the evaluation of heat resistance, three sheets of packaging materials according to Examples 1 to 11 and Comparative Examples 1 to 3 were prepared, respectively, and the base material layer faced up so that the base material layer and the thermal adhesive layer faced each other. The packaging materials were stacked and aged at a temperature of 60 ° C. for 5 days in a state where a load of 1 kg / cm ² was applied to the base material layer side of the packaging material disposed on the top. Next, one of the three stacked sheets was removed and subjected to a post-heating treatment at 190 ° C. for 1 minute under no load. At this time, after the aging treatment and the post-heating treatment, the base material layer of the packaging material was visually observed and the static friction coefficient of the packaging material surface was measured with a friction meter (manufactured by Shinto Chemical Co., Ltd.) with a load of 100 g, an area of 60 mm × 60 mm, Measurement was performed at a pulling speed of 100 mm / sec. The results are shown in Table 2.

  As shown in Table 2, the packaging materials according to Examples 1 to 10 had a static friction coefficient of 1.0 or less, which was lower than the packaging materials according to Comparative Examples 1, 2, and 3. Moreover, since the packaging material which concerns on the comparative example 1 and the comparative example 3 did not add the hardening | curing agent and the crosslinking agent, blocking generate | occur | produced between the protective layer and the heat bonding layer during the aging process. For this reason, the packaging materials according to Comparative Example 1 and Comparative Example 3 deteriorated the appearance of the protective layer and the slip property (x). In addition, since the packaging material according to Comparative Example 2 was added with isocyan as a curing agent, blocking due to aging did not occur (◯), but the appearance was wrinkled by post-heat treatment and the slip property was deteriorated (×). .

  In the packaging materials according to Examples 1 to 11, the matte tone on the surface of the protective layer was not reduced by aging treatment and post-heating treatment (◯). Further, there was no increase in the coefficient of static friction after the aging treatment and the post-heating treatment. On the other hand, the packaging materials according to Comparative Example 2 and Comparative Example 3 had a thin matte surface after aging treatment (x). Furthermore, an increase in the coefficient of static friction was observed.

[Evaluation of printability]
Evaluation of printability is performed on the surface of the base material layer side of the packaging materials according to Examples 1 to 11 and Comparative Examples 1 to 3 with a commercially available alcoholic magic (diameter of pen nib is 2 mm) and oily magic (diameter of nib is nib). 2 mm) was used to visually observe whether the ink was repelled on the surface of the base material layer immediately after drawing a straight line having a length of 5 cm. Next, after standing at room temperature (25 ° C.) for 5 minutes, the ink was rubbed once with a waste cloth and the straight line was visually observed. The results are shown in Table 3.

[Evaluation of alcohol resistance]
The alcohol resistance was evaluated by visual observation after rubbing the surface of the base material layer of the packaging material according to Examples 1 to 11 and Comparative Examples 1 to 3 with a waste infiltrated with ethanol. The wiping operation was performed by using a cloth soaked with 99.99% ethanol and rubbing the packaging material 10 times at a room temperature of 25 ° C. in a 50 mm × 50 mm range with a load of 200 g. The results are shown in Table 3.

  As shown in Table 3, alcoholic ink and oil-based ink were not repelled in the packaging materials according to Examples 1 to 11 (◯). on the other hand. The packaging material according to Comparative Example 3 repelled alcoholic ink and oily ink (×). Moreover, the packaging material which concerns on Examples 1-10 did not observe deterioration of the surface of a protective layer, even after rubbing with the waste in which ethanol was impregnated ((circle)). On the other hand, after the packaging material according to Comparative Example 2 was rubbed with waste cloth, the matte tone on the surface of the protective layer was thinned in part of the appearance (×). Further, part of the appearance of the packaging material according to Comparative Example 3 was sticky on the surface of the protective layer (x).

  INDUSTRIAL APPLICABILITY The present invention can be used as a package for packaging chemical batteries such as nickel metal hydride batteries, nickel cadmium batteries, lithium metal primary batteries or secondary batteries, lithium polymer batteries, and electric double layer capacitors, capacitors, and electrolytic capacitors.

DESCRIPTION OF SYMBOLS 110 Packaging material 111 Protective layer 112 Base material layer 113 Adhesive layer 114 Barrier layer 115 Acid-modified polyolefin layer 116 Thermal adhesive layer 120 Package 120a Storage part 120b Lid part 121 Lithium ion battery 122 Lithium ion battery main body 123a Positive electrode tab 123b Negative electrode tab

According to the present invention, in the packaging material for electrochemical cell of the above structure is characterized in that amine contained in the crosslinking agent is a mixture of Ben zo guanamine or melamine or benzoguanamine and melamine. According to this configuration, the electrolytic solution resistance, alcohol resistance, and heat resistance of the protective layer are further improved.

Further, with the mixture of amines Ben zo guanamine or melamine or benzoguanamine and melamine contained in the crosslinking agent, electrolyte resistance of the protective layer 111, alcohol resistance and heat resistance are further improved.

Claims (7)

  A packaging material for an electrochemical cell in which at least a base material layer, an adhesive layer, a barrier layer made of a metal foil, and a thermal adhesive layer made of a heat-adhesive resin are sequentially laminated from the outside, and the outer surface of the base material layer A packaging material for an electrochemical cell comprising a protective layer made of a resin comprising a main agent, a curing agent, and a crosslinking agent containing an amine.   The packaging material for an electrochemical cell according to claim 1, wherein the amine contained in the crosslinking agent is benguanamine, melamine, or a mixture of benzoguanamine and melamine.   The packaging material for an electrochemical cell according to claim 1 or 2, wherein the resin constituting the protective layer contains a matting agent.   The electrochemical cell packaging material according to any one of claims 1 to 3, wherein a slip agent is contained in the resin constituting the protective layer.   The packaging material for an electrochemical cell according to any one of claims 1 to 3, wherein a slip film formed of a slip agent is formed on an upper surface of the protective layer.   The packaging material for an electrochemical cell according to any one of claims 1 to 5, wherein the base material layer is made of a stretched polyamide film.   The packaging material for an electrochemical cell according to any one of claims 1 to 5, wherein the base material layer comprises a stretched polyester film.

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