JP2014135282A - Polymer battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the composition of a laminate which is used as sheet for a case which accommodates a polymer battery, excels in moisture vapor and other gas barrier properties, has mechanical strength including stress cracking resistance and piercing resistance, and also is usable at high temperature and stable against an electrolyte.SOLUTION: A polymer battery packaging material consists of a laminate comprising an outermost layer, a barrier layer and an innermost layer, or an outermost layer, a barrier layer, an intermediate layer and an innermost layer. The innermost layer consisting of two or more layers formed by a co-extrusion method, including a resin layer where innermost layers themselves are thermo-adhesive to each other. The resin which makes the innermost layers thermo-adhesive to metal is one of acid modified polyolefin, acid modified polyethylene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer and ionomer, and the resin which does not have a thermo-adhesive property for metal but makes the innermost layers thermo-adhesive to each other is polyolefin.

Description

  The present invention relates to a laminate having moisture resistance and content resistance and a packaging material for a polymer battery having the solid organic electrolyte (polymer polymer electrolyte) using the laminate.

  The polymer battery is also referred to as a lithium secondary battery, and is a battery that has a polymer electrolyte and generates a current by the movement of lithium ions, and includes a positive electrode / negative electrode active material made of a polymer. The configuration of the lithium secondary battery is as follows: positive electrode current collector (aluminum, nickel) / positive electrode active material layer (made of polymer positive electrode material such as metal oxide, carbon black, metal sulfide, electrolyte, polyacrylonitrile) / electrolyte layer / (Carbon-based electrolytes such as propylene carbonate, ethylene carbonate, dimethyl carbonate, ethylene methyl carbonate, inorganic solid electrolytes made of lithium salts, gel electrolytes, etc./negative electrode active substance layer (lithium metal, alloy, carbon, electrolyte, It consists of a polymer negative electrode material such as polyacrylonitrile / negative electrode current collector (copper, nickel, stainless steel) and an outer package that wraps them, and uses of polymer batteries include personal computers, portable terminal devices (cell phones, PDAs, etc.), For video cameras, electric vehicles, energy storage batteries, robots, satellites, etc. The polymer battery has a positive electrode current collector made of aluminum, nickel, etc., a positive electrode active material made of a polymer positive electrode material such as metal oxide, carbon black, metal sulfide, electrolyte, polyacrylonitrile, etc. Layer, carbonate electrolyte such as propylene carbonate, ethylene carbonate, dimethyl carbonate, ethyl carbonate, ethylene methyl carbonate, inorganic solid electrolyte made of lithium salt, electrolyte layer made of gel electrolyte, lithium metal, alloy, carbon, electrolyte, It consists of a polymer battery body composed of a negative electrode active material layer such as polyacrylonitrile, a negative electrode current collector such as copper, nickel, and stainless steel, and an outer package that wraps the polymer battery. Metal cans that are made into a cylindrical or rectangular parallelepiped shape, or , That a multilayer film composed of the outermost layer / aluminum / sealant layer was in a bag shape it has been used.

  However, there have been the following problems as the outer package of the polymer battery. In a metal can, since the outer wall of the container is rigid, the shape of the battery itself is determined. Therefore, since the hardware side is designed in accordance with the battery, the size of the hardware using the battery is determined by the battery, and the degree of freedom in shape is reduced. In addition, the bag-shaped outer package made of a multilayer film is not limited in the degree of freedom of the shape of the hardware using the battery, as in the metal can, but the physical properties required for the outer package of the polymer battery The present condition is that the packaging material which can fully satisfy a function has not been developed yet. The required physical properties and functions are as follows. For example, as an exterior body of a polymer battery, it is necessary to hold a part of an electrode that connects the base part of the polymer battery body, the hardware, and the battery body in a sealed system that is cut off from the outside air. The innermost layer needs to have adhesiveness with the electrode, particularly heat sealability. Since the electrode is made of metal, the innermost layer is required to have heat sealability with the metal. In addition, the polymer battery has a heat seal stability and a sealing system due to the temperature rise of the battery, which is the content of the battery due to charging / discharging, and the environmental temperature used is, for example, a car dashboard in the summer or cold in the winter. Heat resistance and cold resistance are required in addition to hardware used to withstand use on the ground, etc. Even under the severe environment described above, it is required to ensure heat seal stability and a sealing system as an exterior body. Therefore, when a heat-adhesive resin having metal adhesion and heat resistance is used as the innermost layer of the laminate that forms the exterior body of the polymer battery, the adhesion to the metal, heat resistance, etc. are improved. However, as the innermost layer resin, it becomes rigid and stress cracks due to bending or the like may occur. In the case of a polymer battery, an electrolyte composed of a carbonate-based solvent and a lithium salt as a battery content may adversely affect the exterior body and reduce the adhesive strength between the multilayer film layers. That is, since it contains a solvent (carbonate type), the solvent swells the adhesive layer between the multilayer film layers and decreases the adhesive strength. Furthermore, acid and heat are generated by hydrolysis of the electrolyte, and the barrier layer made of metal is corroded to lower the adhesion strength between the layers. Further, the battery may ignite due to the generated heat. Moreover, the battery electromotive force is lowered due to the temperature rise, and the connected device may stop or break down. The hydrolysis of the electrolyte, which causes these problems, is due to the penetration of moisture from the outside into the battery sealing system. Therefore, the exterior body is required to block water vapor from the outside (barrier property). Further, not only polymer batteries but also battery outer bodies are required to have a structure that does not energize equipment (hardware) around the outer body and that the electrodes do not contact each other and short-circuit. In addition to the metal can and the bag, a shape sealed with a molding tray and a lid material is also conceivable as an outer package of the polymer battery. Also in this case, selection of the innermost layer resin having heat sealability and a laminate having good moldability when molding the tray have been demanded. The present invention is excellent in water vapor and other gas barrier properties as a sheet used for a case for storing a polymer battery, and has mechanical strength such as stress crack resistance and puncture resistance, and can be used at high temperatures. The present invention provides a stable laminate structure for an electrolytic solution.

  The present invention relates to a laminate type polymer battery packaging material comprising an outermost layer / barrier layer / innermost layer or an outermost layer / barrier layer / intermediate layer / innermost layer, wherein the innermost layer is heated against a metal. A laminate comprising at least two coextruded resin layers formed by a coextrusion method including an adhesive resin layer, or an outermost layer / barrier layer / innermost layer, or an outermost layer / barrier layer / intermediate layer / A laminate composed of the innermost layers, or two or more coextruded layers formed by at least a coextrusion method including a resin layer in which the innermost layers do not have thermal adhesiveness to metal but the innermost layers can be thermally bonded to each other. A laminate comprising a resin layer, wherein the resin capable of being thermally bonded to the metal is acid-modified polyolefin, acid-modified polyethylene, ethylene / acrylic acid copolymer, metal ion-crosslinked polyethylene, ethylene or Containing at least one of a copolymer of lene and an acrylic acid derivative or a methacrylic acid derivative and a modified product thereof, the barrier layer comprising aluminum having a thickness of 15 μm or more, and the intermediate layer having a thickness of 10 μm. It must contain at least one layer of the above-mentioned polyester-based, polyolefin-based, fluororesin-based, ethylene / vinyl acetate copolymer saponified resins, or resins formed from these modified products and mixtures. On the inner layer surface side, epoxy, phenol, melamine, alkyd, polyimide, unsaturated polyester, polyurethane, unsaturated carboxylic acid graft polymer, polyethylene terephthalate copolymer, polybutylene terephthalate copolymer Copolyester polyester, metal ion, etc. Cross-linked polyethylene, ethylene / vinyl acetate copolymer system, copolymer system of ethylene and acrylic acid and methacrylic acid, polyether urethane resin and the like, and a resin layer containing at least 30% of these modified products A protective layer is formed, and a polymer battery packaging material using the laminate.

  In the laminate of the present invention, the innermost layer is multilayered to eliminate cracks in the innermost layer, which is a problem in the innermost layer of the resin layer having metal adhesion, and to obtain a stable sealing property. did it. In addition, the polymer battery itself has flexibility and can be made lighter than using a metal can, and the total layer thickness can be reduced, thereby saving space as a battery. In particular, it has excellent barrier properties as a polymer battery packaging material, can maintain the barrier properties for a long time, and can be a packaging material excellent in heat resistance, cold resistance, content resistance, and the like.

Example of packaging material for polymer battery of the present invention, (a) Basic layer structure, (b) Perspective view explaining structure of polymer battery, (c) Cross section of X ₁ -X ₁ part, (d FIG. 4 is a cross-sectional view taken along a line X ₂ -X ₂ . Another embodiment of the polymer battery packaging material of the present invention, (a) basic layer configuration, (b) perspective view explaining the structure of the polymer battery, (c) perspective view of the polymer battery of an embossed type exterior body. Figure is a cross-sectional view of (d) X ₃ -X ₃ parts. It is sectional drawing which shows another Example of the laminated body of this invention. It is explanatory drawing which shows another Example of adhesion | attachment with the exterior body and tab in this invention, (a) The perspective view of a polymer battery, (b) The perspective view of the polymer battery main body which adhere | attached the heat bondable tab material, (c) ) A perspective view of another polymer battery main body to which a heat-adhesive tab material is bonded, and (d) and (e) are X ₄ -X ₄ part cross-sectional views when the respective heat-adhesive tab materials are used. It is the top view which shows the shape of the pouch type exterior body of the polymer battery using the laminated body of this invention, and sectional drawing of each type. The shape of the embossed type exterior body of the polymer battery using the laminate of the present invention is shown. (A) Perspective view of a single-sided embossed type bottom material, (a ′) X ₉ -X ₉ part sectional view, (b) Double-sided embossed Perspective view of type, (b ′) X ₁₀ -X ₁₀ section sectional view, (c) conceptual diagram of another example showing the position of the tab in the embossing tie, (d) example of providing the tab in another position It is a conceptual diagram.

A laminate and a polymer battery packaging material using the same according to the present invention will be described in detail with reference to the drawings. Figure 1 shows an embodiment of a polymer battery packaging material of the present invention, (a) the basic layer structure, (b) a perspective view illustrating a structure of a polymer battery, (c) X ₁ -X ₁ part cross-section Figure is a cross-sectional view of (d) X ₂ -X ₂ parts. FIG. 2 shows another embodiment of the packaging material for a polymer battery of the present invention, (a) a basic layer structure, (b) a perspective view explaining the structure of the polymer battery, and (c) an embossed type exterior body. perspective view of a polymer battery, a cross-sectional view of (d) X ₃ -X ₃ parts. FIG. 3 is a cross-sectional view showing another embodiment of the laminate of the present invention. FIGS. 4A and 4B are explanatory views showing another embodiment of the bonding between the outer package and the tab in the present invention, in which FIG. 4A is a perspective view of a polymer battery, and FIG. 4B is a perspective view of a polymer battery main body to which a heat-adhesive tab material is bonded. Figure, (c) Perspective view of another polymer battery main body to which a heat-adhesive tab material is bonded, (d) and (e) are cross-sectional views taken along line X ₄ -X ₄ when the respective heat-adhesive tab materials are used. It is. FIG. 5 is a plan view showing the shape of a pouch-type exterior body of a polymer battery using the laminate of the present invention and a cross-sectional view of each type. FIG. 6 is a perspective view of an embossed type exterior body of a polymer battery using the laminate of the present invention, (a) a perspective view of a single-sided embossed type bottom material, (a ′) a cross-sectional view taken along X ₉ -X ₉ , b) a perspective view of a double-sided embossed _{type, (b ') X 10 -X} 10 parts cross-sectional view, (conceptual diagram of another example showing the location of the tab in c) embossing Taib, in yet another position (d) is tab It is a conceptual diagram of the example provided.

  As a result of diligent research, the inventors of the present invention are a packaging material having a multilayer structure, which is a laminate made of each material described below, and the innermost layer can be thermally bonded to a metal. It has been found that the problem of the present invention can be solved by forming at least two layers including a resin layer, and the present invention has been completed. Such a polymer battery formed using the laminate according to the present invention has a pouch type as shown in FIG. 1B and an embossed type as shown in FIG. As shown in FIGS. 1B and 1C, the polymer battery body 2 is enclosed in a pillow-type exterior body 4 and a part of the electrode is exposed outside the exterior body. It is. The form of the exterior body relating to the pouch type and the embossed type will be described in detail later. The polymer battery packaging material (or laminate) forming the outer package is basically composed of three layers of outermost layer / barrier layer / innermost layer, and an intermediate layer between the barrier layer and innermost layer. May be provided. FIG. 1A shows a laminate of the four-layer type. The polymer battery using the laminate of the present invention forms a heat seal part including a part of the electrode 3 as shown in FIG.

  In the present invention, the outermost layer 11 is made of stretched polyester or nylon. At this time, examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymer polyester, polycarbonate, and the like. . Examples of nylon include polyamide-based resins, that is, nylon 6, nylon 6,6, a copolymer of nylon 6,6 and nylon 6, nylon 6,10, polymetaxylylene adipamide (MXD6), and the like.

  When the outermost layer 11 is used as a polymer battery, the outermost layer 11 is a portion that is in direct contact with the hardware, so that a resin layer having an insulating property is basically preferable. Considering the existence of pinholes in a single film and the occurrence of pinholes during processing, the outermost layer needs to have a thickness of 6 μm or more, and a preferred thickness is 12 to 25 μm.

In the present invention, the outermost layer 11 can also be laminated in order to improve pinhole resistance and insulation with the hardware when used as a battery outer package. In that case, the outermost layer 11 includes at least one resin layer of two or more layers, and the thickness of each layer is 6 μm or more, preferably 12 to 25 μm. Examples of laminating the outermost layer 11 include the following 1) to 6) although not shown.
1) Stretched polyethylene terephthalate / stretched nylon 2) Stretched nylon / stretched polyethylene terephthalate Mechanical suitability of packaging materials (stability of conveyance in packaging machines and processing machines), surface protection (heat resistance, electrolyte resistance) When the exterior body for a polymer battery is used as an embossed type as a secondary processing, the outermost layer is multilayered for the purpose of reducing the frictional resistance between the mold and the outermost layer during embossing, and the fluororesin is applied to the outermost layer surface. It is preferable to provide a layer, an acrylic resin layer, a silicone resin layer, or the like. For example,
3) Fluorine resin / stretched polyethylene terephthalate (Fluorine resin is a film or formed by drying after liquid coating)
4) Silicone resin / stretched polyethylene terephthalate. The silicone-based resin is formed by drying after film-like material or liquid coating.
5) Fluorine resin / stretched polyethylene terephthalate / stretched nylon 6) Silicone resin / stretched polyethylene terephthalate / stretched nylon 7) Acrylic resin / stretched nylon (Acrylic resin is a film or cured after drying by liquid coating)

  The outermost layer 11 is bonded to the barrier layer 12 by dry lamination, extrusion lamination, or the like.

  The barrier layer 12 is a layer for preventing water vapor from entering the inside of the polymer battery 1 from the outside, and stabilizes pinholes and processability (pouching, embossing formability) of the barrier layer alone, In order to provide pinhole resistance, a metal such as aluminum or nickel having a thickness of 15 μm or more, or an inorganic compound such as silicon oxide or alumina can be used, but the barrier layer is preferably 20 to 80 μm aluminum. In order to further improve the generation of pinholes and make the polymer battery exterior body an embossed type, the aluminum material used as the barrier layer has an iron content in order to prevent the occurrence of cracks in the embossed part. Is 0.3 to 9.0%, preferably 0.7 to 2.0%. When the iron content is less than 0.3%, effects such as prevention of pinholes and improvement of embossing formability are not observed, and when the iron content of the aluminum exceeds 9.0% , The flexibility as aluminum is hindered, and the bag-making property is deteriorated as a laminate. In addition, the acrylic acid produced by cold rolling changes its flexibility, waist strength, and hardness under annealing (so-called annealing treatment) conditions, but the aluminum used in this example is not annealed, A so-called hard-processed product is preferably a flexible hard-processed product appropriately annealed. The degree of softness may be appropriately selected according to the processing suitability.

This aluminum undergoes surface corrosion due to a chemical reaction between aluminum oxide existing on the aluminum surface and hydrogen fluoride (chemical formula: HF) generated when the electrolytic solution reacts with moisture. Therefore, it is preferable to perform surface cleaning with acid / alkali for the purpose of removing oxides and oils on the aluminum surface. Cleaning acids include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrofluoric acid, chromic acid, sulfamic acid, oxalic acid, tartaric acid, citric acid, formic acid, lactic acid, glycolic acid, acetic acid, gluconic acid, There are organic acids such as succinic acid and malic acid, and these may be the main components, and additives may be added as appropriate. In addition, alkalis include hydroxides such as sodium hydroxide, carbonates such as sodium carbonate and sodium bicarbonate, phosphates such as dibasic sodium phosphate and tribasic sodium phosphate, pyropyrosodium phosphate, tripoly -There are polymer phosphates such as sodium phosphate, tetrapoly-sodium phosphate, and silicates such as ortho-sodium silicate and meta-sodium silicate. Although sodium salts are shown, these potassium salts and ammonia salts are also effective. What is necessary is just to add these as a main component and an additive suitably. And in order to improve the chemical resistance and organic solvent resistance of the aluminum surface, a phosphate, chromate, fluoride compound, organosilicon compound, organotitanium compound is formed on the surface of the innermost aluminum layer. A surface treatment layer made of an organic aluminum compound or the like may be provided. Sulfuric acid, oxalic acid, chromic acid, and phosphoric acid may be used, followed by a sealing treatment after anodizing. In addition, for these surface treatment layers, silicon oxide (chemical formula: SiO ₂ ), calcium carbonate, zinc, red lead, zinc zincide, lead zinc cyanamide lead, zinc chromate, barium potassium chromate, barium zinc chromate Adding chemicals and the like further improves chemical resistance and organic solvent resistance. Moreover, in order to improve the adhesive strength at the time of lamination, the aluminum surface may be roughened by a chemical or physical method.

  On the other hand, aluminum as a packaging material is often laminated with other materials as a material having a barrier property, but aluminum is relatively easily corroded by organic solvents, acids, alkalis, and the like among metals. For example, many polymer batteries include an organic solvent such as ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, and acetone in the active material and polymer electrolyte in the polymer battery body. The lithium salt of the polymer electrolyte reacts with water to generate hydrogen fluoride (HF), which is a strong acid. When the aluminum surface is corroded by such an organic solvent, acid or the like, the adhesive strength with the innermost layer or the intermediate layer is weakened, causing delamination and the function as a packaging material is lost. Therefore, the present inventor has conducted various experiments and the like to form a resin layer having solvent resistance and acid resistance on the surface of the surface treatment layer TR as shown in FIG. We found that we can prevent. It was confirmed that the resin layer (hereinafter referred to as the protective layer 15) surprisingly not only protects the aluminum surface but also has adhesiveness with the intermediate layer 14. In the present invention, an epoxy resin, a phenol resin, a melamine resin, an olefin resin, or the like can be used as a substance used for the protective layer 15 provided on the surface of the barrier layer or the surface treatment layer.

In addition, these protective layers include phosphate film forming substances (zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate, silica chromate) and fluoride films. Contains a forming substance (titanium fluoride, zinc fluoride) and an aluminum foil surface adhesion improving substance (coupling agent: silane coupling agent, organic titanium coupling agent, organic aluminum coupling agent) You can also. It is also possible to add silicon oxide (chemical formula: SiO ₂ ), calcium carbonate, zinc, lead tan, lead zincide, lead zinc cyanamide lead, zinc chromate, potassium barium chromate, barium zinc chromate, etc. as appropriate. And organic solvent resistance are further improved. In particular, silicon oxide, calcium carbonate, zinc, red lead, zinc galvanized, zinc cyanamide lead, zinc chromate, potassium barium chromate, barium zinc chromate, etc. are hydrogen fluoride generated by the reaction of electrolyte and moisture (chemical formula : HF) has a chemical reaction and absorbs and adsorbs hydrogen fluoride, and has an effect of preventing corrosion of hydrogen fluoride on each layer, particularly the barrier layer (aluminum).

  In the present invention, the intermediate layer 13 can be provided between the barrier layer 12 or the protective layer and the innermost layer 14. By providing the intermediate layer, the innermost layer 14, which is a heat seal layer, becomes thin due to the protection of the barrier layer 12 and the heat and pressure of heat seal at the time of bag making, and the electrode 3 and aluminum (barrier layer 12) Can be prevented from touching (short circuit occurrence). The intermediate layer 13 is laminated in order to stabilize the environmental suitability (heat resistance, cold resistance) of the battery. The polyester resin has a thickness of 10 μm or more and a melting point of 80 ° C. or more, preferably 12 to 25 μm. And at least one layer formed from a polyolefin-based resin, a fluorine-based resin, or a modified product and a mixture thereof. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, and copolymers or modified products thereof. Examples of the polyolefin resin include polypropylene, ethylene-propylene copolymer, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, and ethylene-α / olefin polymerized using a single site catalyst. Copolymers, metal ion-containing polyethylene, copolymers of ethylene and methacrylic acid or acrylic acid derivatives, polybutene, unsaturated carboxylic acid grafted polyethylene, unsaturated carboxylic acid grafted polypropylene, unsaturated carboxylic acid grafted polymethylpentene and their modifications Things. Examples of the fluororesin include tetrafluoroethylene, trifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene, polychlorotrifluoroethylene, ethylene chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexa. A fluoropropylene copolymer etc. are mentioned. These resins can be used in either a stretched or unstretched state.

  Further, the intermediate layer 13 can be not only a single layer but also a multilayer. When the intermediate layer 13 is multilayered, the formation thereof may be laminated by a coextrusion method, or each layer may be laminated by a dry lamination method. Furthermore, lamination may be performed using an extrusion lamination method. For example, when the intermediate layer 13 is multilayered by a coextrusion method, it has a layer configuration of two or more layers as shown below, and the thickness of each layer is 10 to 100 μm, preferably 15 to 25 μm.

  The innermost layer 14 of the polymer battery packaging material in the present invention includes an olefin resin, an unsaturated carboxylic acid grafted polyolefin, a metal ion crosslinked polyethylene, a copolymer of ethylene or propylene and an acrylic acid derivative, or a methacrylic acid derivative, and these From a modification or mixture of The thickness of the innermost layer is preferably 20 μm or more, the melting point of the resin forming the innermost layer is preferably 70 ° C. or higher, and the Vicat softening point is preferably 60 ° C. or higher.

  Further, the innermost layer 14 forms a sealed system in a state where electrode tabs are sandwiched by a thermal welding method for both the pouch type and the embossed type. However, the olefin resin as the innermost layer of the heat-welded portion becomes brittle because of its characteristics, and cracks and pinholes are easily generated. Also, at the time of thermal welding, the end portion of the electrode tab eliminates pinholes by crushing the innermost layer by the thickness of the tab, but the olefin has a high melting point in order to increase the heat resistance of the innermost layer. When a single-layer resin is used, it must be welded at high temperature, high pressure and for a long time. In this case, the function of the packaging material is deteriorated by reducing the characteristics of the battery in which the heat welding itself is the content or by causing thermal contraction of other constituent layers of the packaging material such as polyester or nylon of the outermost layer. Wake up.

For the innermost layer, it is possible to use a polyolefin-based resin 14 ′ having no metal adhesion, but in this case, the unsaturated carboxylic acid graft graft polyolefin, metal ion-crosslinked polyethylene between the electrode 3 and the innermost layer is used. By using a heat-adhesive tab material (thickness of 15 μm or more) 16 formed from a copolymer of ethylene or propylene and an acrylic acid derivative, or methacrylic acid or a methacrylic acid derivative, the tab and the exterior body are completely Can be glued and sealed. Specifically, as shown in FIG. 4B, a heat-adhesive tab material 16 having a width wider than that of the electrode is placed on the heat-bonding portion of the electrode, inserted into the exterior body, and thermally bonded to be sealed. FIG. 4D schematically shows the X ₄ -X ₄ cross section after thermal bonding in this case (however, the outermost layer, the barrier layer, and the intermediate layer are shown as one layer). 4 (c) shows an unsaturated carboxylic acid graft polyolefin, metal ion-crosslinked polyethylene, ethylene or ethylene or This is an example in which a resin comprising a copolymer of propylene and an acrylic acid derivative or a methacrylic acid derivative and a modified product or a mixture thereof is coated, inserted into an exterior body, and thermally bonded to be sealed. Fig. 4 schematically shows an X ₄ -X ₄ cross section after thermal bonding in this case, as in Fig. 4D.

In order to solve the above-mentioned problems of the present invention, as a result of various studies, the present inventors have found that the innermost layer is multi-layered and found that the problems are effective, and have completed the present invention. Specifically, the innermost layer is multilayered.
(1) Olefin resins and their modified products / unsaturated carboxylic acid grafted polyolefins (2) Olefin resins and their modified products / ethylene and acrylic acid derivatives or ethylene and methacrylic acid derivative copolymers (3) Olefin And the innermost layer having a constitution of a modified resin / metal ion crosslinked polyethylene, metal ion crosslinked polypropylene, or the like. As the typical olefin-based resin, a) as a polypropylene-based resin,
1) Homotype polypropylene (melting point 150 ° C or higher, Vicat softening point 140 ° C or higher)
2) Ethylene-propylene copolymer (random-type propylene or graft-type propylene having a melting point of 110 ° C or higher and a Vicat softening point of 100 ° C or higher)
b) As a polyethylene type,
3) Low density polyethylene having a melting point of 90 ° C. or higher and a Vicat softening point of 80 ° C. or higher, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-propylene-diene copolymer, ethylene-propylene-butene copolymer, An ethylene-α / olefin copolymer polymerized using a single-site catalyst, or an acid-modified polyolefin (melting point 90 ° C. or higher, Vicat softening point 80 ° C. or higher) a) ethylene-vinyl acetate copolymer b) metal ion Crosslinked polyethylene, metal ion crosslinked polypropylene c) Unsaturated carboxylic acid grafted polyolefins such as unsaturated carboxylic acid grafted polyethylene, unsaturated carboxylic acid grafted polypropylene, unsaturated carboxylic acid grafted polymethylpentene, and modified products thereof.
D) As a copolymer of ethylene or propylene and an acrylic acid derivative or methacrylic acid derivative, ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl methacrylate (EMA), ethylene-methyl acrylate copolymer Examples thereof include coalescence (EMAA), ethylene-ethyl acrylate (EEA), ethylene-acrylic acid copolymer (EAA), propylene-ethyl methacrylate (PMA), propylene-ethyl acrylate (PAA), and the like.

As a more specific example of the multilayering of the innermost layer 14, the following configuration can be given.
(1) Low-density polyethylene or linear low-density polyethylene / copolymer of ethylene and methacrylic acid or acrylic acid derivative (2) Ethylene-propylene copolymer / copolymer of propylene and methacrylic acid or acrylic acid derivative (3) Low density polyethylene or linear low density polyethylene / metal cross-linked polyethylene (4) ethylene-propylene copolymer / metal cross-linked polypropylene (5) random propylene / unsaturated carboxylic acid grafted homotype propylene (6) grafted propylene / Unsaturated carboxylic acid grafted homotype propylene (7) Homopropylene type / Unsaturated carboxylic acid grafted random type, or grafted type propylene (8) Random or grafted propylene type / Homopropylene type (9) Ethylene-propylene copolymer / Polyethylene / ethylene-propylene copolymer (10) Ethylene-propylene copolymer / polyethylene / unsaturated carboxylic acid graft polyethylene

  The outermost layer, the barrier layer, the outermost layer, or the outermost layer, the barrier layer, the intermediate layer, and the innermost layer of the packaging material for a polymer battery of the present invention are specifically formed by a T-die method, A film can be formed using an inflation method, a co-extrusion method, or the like, and a secondary film may be formed by a method such as coating, vapor deposition, ultraviolet curing, or electron beam curing, if necessary. In addition, the lamination can be performed by a method such as dry lamination, extrusion lamination, coextrusion lamination, thermal lamination (thermal lamination).

  When performing the above-mentioned dry lamination, polyester-based, polyethyleneimine-based, polyether-based, cyanoacrylate-based, urethane-based, organic titanium-based, polyether-urethane-based, epoxy-based, polyester-urethane-based, simide-based, isocyanate-based, Various polyolefin-based and silicone-based adhesives can be used. However, when dry lamination is performed on the innermost layer side of the laminate of the laminate of the present invention, the adhesive having the above composition is used. Octanoic acid

  Hydrogen fluoride generated by delamination by a carbonate-based solvent that is an electrolyte component of a polymer battery and reaction between a lithium salt and water when the structure of the laminate forming the exterior body for the polymer battery is adhesion by a dry laminate method As a result of diligent research on the problem of peeling of the adhesive surface on the innermost layer side surface of the barrier layer, the following composition of the adhesive is used when dry laminating the adhesion of each layer inside the barrier layer of the laminate. By doing so, it was possible to obtain a laminate having no delamination and peeling of the adhesive surface on the barrier layer surface. The adhesive consists of a main agent and a curing agent. The main agent is sebacic acid, isophthalic acid, terephthalic acid, octanedioic acid, nonanedioic acid, undecanedioic acid, carboxylic acid containing palmitic acid, ethylene glycol, hexanediol, diethylene glycol. The curing agent is composed of glycols such as trimethylolpropane, propylene glycol, dipropylene glycol glycerin, 1,3-butanediol, isocyanates such as TDI, TDA, and the like.

In addition, silicon oxide (chemical formula: SiO ₂ ), calcium carbonate, zinc, lead tan, lead oxide, zinc oxide cyanamide lead, zinc chromate, barium potassium chromate, barium zinc chromate, etc. are appropriately applied to these adhesive layers. Adding it further improves the chemical resistance and organic solvent resistance. In particular, silicon oxide, calcium carbonate, zinc, red lead, lead oxide, zinc cyanamide lead, zinc chromate, potassium barium chromate, barium zinc chromate, etc. are produced by hydrogen fluoride (chemical formula : HF) has a chemical reaction and has an effect of adsorbing hydrogen fluoride suddenly and maleally, and has an effect of preventing corrosion of hydrogen fluoride on each layer, particularly the barrier layer (aluminum).

  In the laminate of the present invention, the dry laminating adhesive for bonding each layer on the innermost layer side with respect to the barrier layer has the above composition. However, when dry lamination is performed on the outer side of the barrier layer, a normal adhesive may be used.

  In addition, when laminating each layer by the above-mentioned extrusion lamination, as an adhesion promotion method for stabilizing the adhesive force between the respective layers to be bonded, the adhesive surface of each layer is polyester-based, polyether-based, urethane-based, polyether-urethane based, polyester Apply urethane resin, such as urethane, isocyanate, polyolefin, polyethyleneimine, cyanoacrylate, organotitanium compound, epoxy, imide, silicone and their modified products, or about 1μm, ozone Surface activation treatment such as treatment can be performed. Further, by using an unsaturated carboxylic acid grafted polyolefin as a resin for the extrusion lamination or thermal lamination, the content resistance and the physical property resistance are improved.

As a method of laminating the laminate of the present invention, in the case of a three-layer structure, as a method of laminating the laminate of the present invention, typically, the following three methods:
1) As a first substrate, prepare a laminate of outermost layer / barrier layer and a second substrate laminate composed of the innermost layer, respectively, and thermally laminate 2) Outer layer / barrier layer, second group as first substrate A method of preparing the innermost layer as a material and performing extrusion lamination (including coextrusion), in this case, performing a thermal lamination process again if necessary 3) Any method of laminating all by dry lamination may be used.

In the case of a four-layer configuration, the following three methods are typically used as a method of stacking:
1) Prepare and thermally laminate a laminate of outermost layer / barrier layer and a second substrate laminate comprising an intermediate layer / innermost layer as the first substrate 2) Outermost layer / barrier layer as the first substrate, As a second substrate, a part of the intermediate layer / innermost layer laminate or only the innermost layer is prepared, and extrusion lamination (including coextrusion) is performed with the intermediate layer. In this case, the thermal lamination process is again performed 3 ) Any method of bonding all together by dry lamination may be used.

  In addition, as an intermediate layer, gas, liquid, ion permeation prevention thin film layer is formed by sputtering, chemical vapor deposition, physical vapor deposition, metal thin film layer such as aluminum layer, metal oxide such as aluminum oxide or tin oxide. By forming a vinylidene chloride layer or the like using a layer or a coating method, it is possible to further prevent permeation of the electrolyte constituent material to the barrier layer and to provide stable adhesion.

When the layer structure of the laminate of the present invention described above is specifically shown as a pouch type and an emboss type, the pouch specifications include [abbreviation: PET: polyester, DL: dry lamination, TL: thermal lamination, AL: Aluminum, PP: Polypropylene, Tr-Ac: Surface treatment with phosphate, RAM-PP: Random polymerized polypropylene, HOMO-PP: Homotype polypropylene, Tr-Co-Ac-cr: Calcium phosphate added chromium phosphate treatment , PPa: Unsaturated carboxylic acid grafted polypropylene, PE: Low density polyethylene, PEa: Unsaturated carboxylic acid grafted polyethylene, Ny: Nylon, AC: Acrylic resin, //: Laminated portion by coextrusion method, (··) numbers Indicates the thickness of the layer, μm]. Adhesives for dry lamination was used in are as follows.
DL-1: Adhesive based on polyether, Takelac A-969V / A-5 (trade name, manufactured by Takeda Pharmaceutical Company Limited)
DL-2: The component composition is as follows. The polyester polyurethane resin is an epoxy resin composed of a carboxylic acid composed of sebacic acid, isophthalic acid, terephthalic acid, and a glycol composed of ethylene glycol, hexanediol, isocyanate (IPDI) and bisphenol A. In addition, as the curing agent, a trimethylolpropane, propylene glycol, dipropylene glycol, glycerin, glycol composed of 1,3-butanediol, isocyanate (TDI), and others (TDA) were used.

Example 1
A biaxially stretched polyester film (12 μm) and aluminum (20 μm) are bonded together by a dry lamination method using an adhesive DL-1 to form a laminate A. Separately, random type polypropylene and unsaturated carboxylic acid grafted polypropylene are coextruded. The aluminum surface of the laminate A, a biaxially stretched polyester film (12 μm), and the random type polypropylene surface formed by the co-extrusion method are bonded by a dry lamination method using an adhesive DL-2. Together, a laminate (1) was obtained.
(1). PET (12) / DL-1 / AL (20) / DL-2 / PET (12) / DL-2 / RAM-PP (30) // PPa (20)

(Example 2)
A biaxially stretched polyester film (12 μm) and aluminum (20 μm) are laminated by a dry lamination method using an adhesive DL-1 to form a laminate A, an unsaturated carboxylic acid grafted polypropylene (20 μm) and a biaxially stretched polyester film (12 μm). And a random type polypropylene surface of a co-extruded film formed by co-extrusion of a random type polypropylene and an unsaturated carboxylic acid grafted polypropylene are laminated by a dry lamination method using an adhesive DL-2 to form a laminate B, The aluminum surface of the laminate A and the unsaturated carboxylic acid grafted polypropylene (20 μm) surface of the laminate B are bonded together by a thermal lamination method under the conditions of a temperature of 250 ° C., a pressure of 0.6 Mpa, and a line speed of 20 meters / minute. A laminate (2) was obtained.
(2). PET (12) / DL-1 / AL (20) / TL / PPa (20) / DL-2 / PET (12) / DL-2 / RAM-PP (25) // PPa (25)

(Example 3)
After forming an acid-resistant modified film by subjecting aluminum (20 μm) to a phosphate treatment, a biaxially stretched polyester film (12 μm) and the aluminum are bonded together by a dry lamination method using an adhesive DL-1, and laminate A Separately, a random type polypropylene and a homotype polypropylene are formed by coextrusion, and the aluminum surface of the laminate A and the random type polypropylene surface formed by the coextrusion method are used with an adhesive DL-2. Then, the laminate (3) was obtained by pasting together by a dry lamination method.
(3). PET (12) / DL-1 / AL (20) / Tr-Ac / DL-2 / RAM-PP (5) / HOMO-PP (25)

In addition, as an emboss specification,
(Example 4)
A biaxially stretched polyester film (12 μm), a biaxially stretched nylon film (15 μm), and aluminum (50 μm) are laminated together by the dry lamination method in sequence using an adhesive DL-1, and separately from polyethylene and unsaturated. Carboxylic acid grafted polyethylene is formed into a film by coextrusion method, and the aluminum surface of the laminate A, the polyester film (16 μm), and the polyethylene surface formed by the coextrusion method are used with an adhesive DL-2. By sequentially laminating by a dry lamination method, a laminate (4) was obtained.
(4). PET (12) / DL-1 / Ny (15) / DL-1 / AL (50) / DL-2 / PET (16) / DL-2 / PE (30) // PEa (20)

(Example 5)
A biaxially stretched polyester film (12 μm), a biaxially stretched nylon film (15 μm), and aluminum (50 μm) are laminated by a dry lamination method using an adhesive DL-1 to form a laminate A, and an unsaturated carboxylic acid grafted polypropylene (20 μm) ) And a biaxially stretched copolyester film (16 μm), a polyethylene film co-extruded with polyethylene side of unsaturated carboxylic acid grafted polyethylene (50 μm), and laminated by dry lamination method using adhesive DL-2. Laminate B was bonded to the aluminum surface of Laminate A by an unsaturated carboxylic acid grafted polypropylene (20 μm) of Lamination B by a thermal lamination method at a temperature of 200 to 250 ° C., a pressure of 0.6 Mpa, and a line speed of 25 meters / min. Thereby to obtain a laminate (5).
(5). PET (12) / DL-1 / Ny (15) / DL-1 / AL (50) / TL / PPa (20) / DL-2 / PET (16) / DL-2 / PE (25) // PEa (25)

(Example 6)
A laminate DL-1 is formed by coating the nylon side of a biaxially stretched nylon film (15 μm) formed by coating an acrylic resin (3 μm) on the outermost layer surface and aluminum (50 μm) treated with calcium carbonate-added chromic phosphate. Then, the laminate A was laminated by the dry lamination method in sequence, and a random type polypropylene and a homotype polypropylene were separately formed by the coextrusion method, and the aluminum surface of the laminate A was formed by the coextrusion method. The random type polypropylene surface was bonded by a dry lamination method using an adhesive DL-2 to obtain a laminate (6).
(6). AC / DL-1 / Ny (15) / DL-1 / AL (50) / Tr-Co-Ac-cr / DL-2 / RAM-PP (5) // HOMO-PP (25)
The embossed type PET (16 μm) is a copolymer type polyester. Further, the adhesive used for the DL-1 is not particularly limited, but for the DL-2, the adhesive having the composition described in the present invention is used. Using the laminates (1) to (6), the polymer battery main body was sealed as a polymer battery packaging material, and various tests were performed, but the laminate satisfying the performance required as a polymer battery outer package. Met.

  FIG. 3 shows another embodiment as a specific layer structure. This laminate is a two-layer type in which a base material layer and a barrier layer are dry-laminated, a protective layer 15 is provided on the barrier layer to form a first base material, and an intermediate layer is dry-laminated (DL-2). The innermost layer has a two-layer structure formed by the co-extrusion method of 14a and 14b, and the innermost layer and the intermediate layer are dry-laminated (DL-3) to serve as a second base material with a thermal adhesive film interposed therebetween. This is an example in which a heat laminate layer TL is formed by heat lamination.

Polymer battery configuration (pouch-type exterior)
In the case of using the laminate of the present invention as a packaging material constituting the exterior body of the polymer battery, the form of the exterior body may be a pouch type or an embossed type. In addition to the pillow type described above, the pouch type includes a three-side seal type shown in FIG. 5A and a four-side seal type shown in FIG. 5B. In any form, the seal end part is a hermetic seal including a part of the tab (electrode), and a part of the tab is exposed to the outside of the exterior body. The tab 3 may be exposed to the outside from an arbitrary position of the seal portion of the exterior body as shown in FIGS. 5 (c), 5 (d), and 5 (e).

  In the polymer battery packaging material of the present invention, the shape of the exterior body 4 may be an embossing system as shown in FIG. In this case, the bottom material 6 includes an embossed portion 8 that serves as a storage portion for the battery body, and a flange portion 9 that seals and seals the lid material 7. As shown in FIG. 2 (a), the bottom packaging material 6 is basically a four-layer laminate, and a polyester resin used for the outermost layer 11 and / or the intermediate layer 13 is made of a polyethylene terephthalate copolymer or It is preferable to use a polybutylene terephthalate copolymer and reduce the draw ratio in film formation. By using the copolymer, the embossed shape of the bottom material 6 becomes sharp, and when the container is used, the opening width (T) and depth (D) shown in FIG. = 1/50 or more and the side taper θ can be 130 ° or less, and embossing is easy. When aluminum is used for the barrier layer, it is desirable that the thickness is 30 μm or more so that there is no fear of pinholes due to embossing. In the case of embossing only on one side, the lid member 7 does not need to be a copolymer because it is not molded. When embossing on both sides, a laminate of the bottom material may be used on both sides. By making the exterior body of the polymer battery an embossed type, the battery body can be stored better.

DESCRIPTION OF SYMBOLS 1 Polymer battery 2 Polymer battery main body 3 Electrode 4 Exterior body 5 Heat seal part 5f Back seal part 6 Bottom material 7 Lid material 8 Embossed part 9 Flange part 10 Laminated body (packaging material)
DESCRIPTION OF SYMBOLS 11 Outermost layer 12 Barrier layer 13 Intermediate | middle layer 14,14 'Inner layer 15 Protective layer 16 Thermal-adhesive tab material DL Dry laminated layer TL Thermal laminated layer

The present invention relates to a polymer battery packaging material having moisture resistance and content resistance, and a polymer battery having a solid organic electrolyte (polymer polymer electrolyte) using the same .

The present invention relates to a polymer battery in which a polymer battery body is packaged with a polymer battery packaging material with a tab protruding outward, and is sealed with a peripheral heat bonding portion, and the polymer battery packaging material is formed of an outer layer / aluminum. At least 2 formed by a coextrusion method including a barrier layer / inner layer or an outer layer / aluminum barrier layer / intermediate layer / inner layer, and the inner layer includes a resin layer capable of being thermally bonded to a metal. The peripheral heat-bonded portion formed of a co-extruded resin layer of at least layers and sealed by protruding the tab is thermally bonded by sandwiching the tab directly between the innermost layers of the polymer battery packaging material. Polymer battery (however, an adhesive skin formed by applying and drying an organosol containing acid-modified polyolefin as a solid component between the barrier layer and the inner layer) Which comprises a, and a excluding those comprising a layer comprising a cyclic olefin copolymer to at least one of the intermediate layer and the inner layer), the heat bondable resin to the metal, the unsaturated carboxylic acid graft polyolefin, metal Including at least one of ion-crosslinked polyethylene, a copolymer of ethylene or propylene and an acrylic acid derivative or a methacrylic acid derivative, and a modified product thereof, the barrier layer having a thickness of 15 μm or more , the intermediate The layer includes at least one layer of a polyester, polyolefin, fluororesin, saponified ethylene / vinyl acetate copolymer, or a resin formed from a modified product and a mixture thereof having a thickness of 10 μm or more. it, on the innermost layer side surface of the barrier layer, epoxy, phenolic Melamine, alkyd, polyimide, unsaturated polyester, polyurethane, unsaturated carboxylic acid graft polymers based, polyethylene terephthalate copolymers, polybutylene terephthalate copolymer copolymer polyester consisting of either system, the metal ion Protection comprising a cross-linked polyethylene, an ethylene / vinyl acetate copolymer system, a copolymer system of ethylene and acrylic acid and methacrylic acid, a polyether urethane resin , and a resin layer containing at least 30% of these modified products it is intended to include that the layers are formed.

In the present invention, by forming the inner layer into multiple layers , cracks in the inner layer , which has been a problem in the inner layer of a single resin layer having metal adhesion, are eliminated, and stable sealing performance can be obtained. In addition, the polymer battery itself has flexibility and can be made lighter than using a metal can, and the total layer thickness can be reduced, thereby saving space as a battery. In particular, excellent barrier properties, it can capable of maintaining the barrier properties for long-term heat resistance, it was possible to obtain excellent cold resistance, the content resistance, and the like.

As a result of diligent research, the inventors of the present invention are a packaging material having a multilayer structure, which is a laminate made of each material described below, and the innermost layer can be thermally bonded to a metal. It has been found that the problem of the present invention can be solved by forming at least two layers including a resin layer, and the present invention has been completed. Such a polymer battery formed using the laminate according to the present invention has a pouch type as shown in FIG. 1B and an embossed type as shown in FIG. As shown in FIGS. 1B and 1C, the polymer battery body 2 is enclosed in a pillow-type exterior body 4 and a part of the electrode is exposed outside the exterior body. It is. The form of the exterior body relating to the pouch type and the embossed type will be described in detail later. The polymer battery packaging material (or laminate) forming the outer package is basically composed of three layers of outer layer / barrier layer / inner layer, and an intermediate layer is provided between the barrier layer and the inner layer. Also good. FIG. 1A shows a laminate of the four-layer type. The polymer battery using the laminate of the present invention forms a heat seal part including a part of the electrode 3 as shown in FIG.

The outer layer 11 in the present invention is made of stretched polyester or nylon. In this case, examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate. Examples of nylon include polyamide-based resins, that is, nylon 6, nylon 6,6, a copolymer of nylon 6,6 and nylon 6, nylon 6,10, polymetaxylylene adipamide (MXD6), and the like.

When the outer layer 11 is used as a polymer battery, the outer layer 11 is a part that comes into direct contact with the hardware. Therefore, a resin layer having an insulating property is basically preferable. Considering the existence of pinholes in a single film and the occurrence of pinholes during processing, the outermost layer needs to have a thickness of 6 μm or more, and a preferred thickness is 12 to 25 μm.

In the present invention, the outer layer 11 can be laminated in order to improve pinhole resistance and insulation with the hardware when it is used as a battery outer package. In that case, the outermost layer 11 includes at least one resin layer of two or more layers, and the thickness of each layer is 6 μm or more, preferably 12 to 25 μm. Examples of laminating the outer layer 11 include the following 1) to 6) although not shown.
1) Stretched polyethylene terephthalate / stretched nylon 2) Stretched nylon / stretched polyethylene terephthalate Mechanical suitability of packaging materials (stability of conveyance in packaging machines and processing machines), surface protection (heat resistance, electrolyte resistance) When the exterior body for a polymer battery is used as an embossed type as a secondary processing, the outermost layer is multilayered for the purpose of reducing the frictional resistance between the mold and the outermost layer during embossing, and the fluororesin is applied to the outermost layer surface. It is preferable to provide a layer, an acrylic resin layer, a silicone resin layer, or the like. For example,
3) Fluorine resin / stretched polyethylene terephthalate (Fluorine resin is a film or formed by drying after liquid coating)
4) Silicone resin / stretched polyethylene terephthalate. The silicone-based resin is formed by drying after film-like material or liquid coating.
5) Fluorine resin / stretched polyethylene terephthalate / stretched nylon 6) Silicone resin / stretched polyethylene terephthalate / stretched nylon 7) Acrylic resin / stretched nylon (Acrylic resin is a film or cured after drying by liquid coating)

The outer layer 11 is bonded to the barrier layer 12 by dry lamination, extrusion lamination, or the like.

On the other hand, aluminum as a packaging material is often laminated with other materials as a material having a barrier property, but aluminum is relatively easily corroded by organic solvents, acids, alkalis, and the like among metals. For example, many polymer batteries include an organic solvent such as ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, and acetone in the active material and polymer electrolyte in the polymer battery body. The lithium salt of the polymer electrolyte reacts with water to generate hydrogen fluoride (HF), which is a strong acid. When the aluminum surface is corroded by such an organic solvent, acid or the like, the adhesive strength with the inner layer or the intermediate layer is weakened, causing delamination and the function as a packaging material is lost. Accordingly, the present inventors have more various experiments, solvent resistance to the surface treatment layer surface, by forming a resin layer having acid resistance was found to be able to prevent the surface of aluminum corrosion. Then, it was confirmed that the resin layer (hereinafter referred to as the protective layer 15) surprisingly not only protects the aluminum surface but also has adhesiveness with the intermediate layer 13 . In the present invention, an epoxy resin, a phenol resin, a melamine resin, an olefin resin, or the like can be used as a substance used for the protective layer 15 provided on the surface of the barrier layer or the surface treatment layer.

In the present invention, the intermediate layer 13 can be provided between the barrier layer 12 or the protective layer and the inner layer 14. By providing the intermediate layer, the inner layer 14, which is a heat seal layer, becomes thin due to the protection of the barrier layer 12 and the heat and pressure of heat seal at the time of bag making, and the electrode 3 and aluminum (barrier layer 12) Contact (short circuit occurrence) can be prevented. The intermediate layer 13 is laminated in order to stabilize the environmental suitability (heat resistance, cold resistance) of the battery. The polyester resin has a thickness of 10 μm or more and a melting point of 80 ° C. or more, preferably 12 to 25 μm. And at least one layer formed from a polyolefin-based resin, a fluorine-based resin, or a modified product and a mixture thereof. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, and copolymers or modified products thereof. Examples of the polyolefin resin include polypropylene, ethylene-propylene copolymer, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, and ethylene-α / olefin polymerized using a single site catalyst. Copolymers, metal ion-containing polyethylene, copolymers of ethylene and methacrylic acid or acrylic acid derivatives, polybutene, unsaturated carboxylic acid grafted polyethylene, unsaturated carboxylic acid grafted polypropylene, unsaturated carboxylic acid grafted polymethylpentene and their modifications Things. Examples of the fluororesin include tetrafluoroethylene, trifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene, polychlorotrifluoroethylene, ethylene chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexa. A fluoropropylene copolymer etc. are mentioned. These resins can be used in either a stretched or unstretched state.

The innermost layer of the packaging material for a polymer battery in the present invention includes an olefin resin, an unsaturated carboxylic acid grafted polyolefin, a metal ion-crosslinked polyethylene, a copolymer of ethylene or propylene and an acrylic acid derivative, or a methacrylic acid derivative, and these It is formed from a modification or a mixture. The thickness of the innermost layer is preferably 20 μm or more, the melting point of the resin forming the innermost layer is preferably 70 ° C. or higher, and the Vicat softening point is preferably 60 ° C. or higher.

Furthermore, the innermost layer forms a sealed system with electrode tabs sandwiched by a thermal welding method for both the pouch type and the embossed type. However, the olefin resin as the innermost layer of the heat-welded portion becomes brittle because of its characteristics, and cracks and pinholes are easily generated. Also, at the time of thermal welding, the end portion of the electrode tab eliminates pinholes by crushing the innermost layer by the thickness of the tab, but the olefin has a high melting point in order to increase the heat resistance of the innermost layer. When a single-layer resin is used, it must be welded at high temperature, high pressure and for a long time. In this case, the function of the packaging material may be deteriorated by deteriorating the characteristics of the battery in which the heat welding itself is the content, or by causing other constituent layers of the packaging material such as polyester or nylon of the outer layer to undergo thermal shrinkage. Wake up.

For the innermost layer, it is possible to use a polyolefin-based resin 14 ′ having no metal adhesion, but in this case, the unsaturated carboxylic acid graft graft polyolefin, metal ion-crosslinked polyethylene between the electrode 3 and the innermost layer is used. By using a heat-adhesive tab material (thickness of 15 μm or more) 16 formed from a copolymer of ethylene or propylene and an acrylic acid derivative, or methacrylic acid or a methacrylic acid derivative, the tab and the exterior body are completely Can be glued and sealed. Specifically, as shown in FIG. 4B, a heat-adhesive tab material 16 having a width wider than that of the electrode is placed on the heat-bonding portion of the electrode, inserted into the exterior body, and thermally bonded to be sealed. FIG. 4D schematically shows the X ₄ -X ₄ cross section after thermal bonding in this case (however, the outer layer , the barrier layer, and the intermediate layer are shown as one layer). 4 (c) shows an unsaturated carboxylic acid graft polyolefin, metal ion-crosslinked polyethylene, ethylene or ethylene or This is an example in which a resin comprising a copolymer of propylene and an acrylic acid derivative or a methacrylic acid derivative and a modified product or a mixture thereof is coated, inserted into an exterior body, and thermally bonded to be sealed. Fig. 4 schematically shows an X ₄ -X ₄ cross section after thermal bonding in this case, as in Fig. 4D.

In order to solve the above-mentioned problems of the present invention, as a result of various studies, the present inventors have found that the above-mentioned problems are effective by multilayering the inner layer and have completed the present invention. Specifically, the inner layer is multilayered.
(1) Olefin resins and their modified products / unsaturated carboxylic acid grafted polyolefins (2) Olefin resins and their modified products / ethylene and acrylic acid derivatives or ethylene and methacrylic acid derivative copolymers (3) Olefin It is to make it an inner layer of composition, such as system resin and these modification thing / metal ion cross-linked polyethylene, metal ion cross-linked polypropylene. As the typical olefin-based resin, a) as a polypropylene-based resin,
1) Homotype polypropylene (melting point 150 ° C or higher, Vicat softening point 140 ° C or higher)
2) Ethylene-propylene copolymer (random-type propylene or graft-type propylene having a melting point of 110 ° C or higher and a Vicat softening point of 100 ° C or higher)
b) As a polyethylene type,
3) Low density polyethylene having a melting point of 90 ° C. or higher and a Vicat softening point of 80 ° C. or higher, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-propylene-diene copolymer, ethylene-propylene-butene copolymer, An ethylene-α / olefin copolymer polymerized using a single-site catalyst, or an acid-modified polyolefin (melting point 90 ° C. or higher, Vicat softening point 80 ° C. or higher) a) ethylene-vinyl acetate copolymer b) metal ion Crosslinked polyethylene, metal ion crosslinked polypropylene c) Unsaturated carboxylic acid grafted polyolefins such as unsaturated carboxylic acid grafted polyethylene, unsaturated carboxylic acid grafted polypropylene, unsaturated carboxylic acid grafted polymethylpentene, and modified products thereof.
D) As a copolymer of ethylene or propylene and an acrylic acid derivative or methacrylic acid derivative, ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl methacrylate (EMA), ethylene-methyl acrylate copolymer (EMAA), ethylene-ethyl acrylate (EEA), ethylene-acrylic acid copolymer (EAA), propylene-ethyl methacrylate (PMA), propylene-ethyl acrylate (PAA), and the like.

As a more specific example of the multi-layered inner layer 14, the following configuration can be given.
(1) Low-density polyethylene or linear low-density polyethylene / copolymer of ethylene and methacrylic acid or acrylic acid derivative (2) Ethylene-propylene copolymer / copolymer of propylene and methacrylic acid or acrylic acid derivative (3) Low density polyethylene or linear low density polyethylene / metal cross-linked polyethylene (4) ethylene-propylene copolymer / metal cross-linked polypropylene (5) random propylene / unsaturated carboxylic acid grafted homotype propylene (6) grafted propylene / Unsaturated carboxylic acid grafted homotype propylene (7) Homopropylene type / Unsaturated carboxylic acid grafted random type, or grafted type propylene (8) Random or grafted propylene type / Homopropylene type (9) Ethylene-propylene copolymer / Polyethylene / ethylene-propylene copolymer (10) Ethylene-propylene copolymer / polyethylene / unsaturated carboxylic acid graft polyethylene

The outer layer , the barrier layer, the inner layer , or the outer layer , the barrier layer, the intermediate layer, and the inner layer of the packaging material for polymer battery of the present invention, or the lamination method between the layers are specifically the T-die method, the inflation method, the common method. A film can be formed using an extrusion method or the like, and if necessary, a secondary film may be formed by a method such as coating, vapor deposition, ultraviolet curing, or electron beam curing. In addition, the lamination can be performed by a method such as dry lamination, extrusion lamination, coextrusion lamination, thermal lamination (thermal lamination).

When performing the above-mentioned dry lamination, polyester-based, polyethyleneimine-based, polyether-based, cyanoacrylate-based, urethane-based, organic titanium-based, polyether-urethane-based, epoxy-based, polyester-urethane-based, simide-based, isocyanate-based, Various polyolefin-based and silicone-based adhesives can be used. However, when dry lamination is performed on the inner layer surface of the laminate of the present invention, the adhesive having the above composition is used .

Hydrogen fluoride generated by delamination by a carbonate-based solvent that is an electrolyte component of a polymer battery and reaction between a lithium salt and water when the structure of the laminate forming the exterior body for the polymer battery is adhesion by a dry laminate method against the adhesive surface peeling the challenges in the barrier layer inner surface by a result of intensive studies, the components of the adhesive at the time of dry lamination adhesion of each layer in the inner side than the barrier layer of the laminate to the composition of the following By doing so, it was possible to obtain a laminate having no delamination and adhesion surface peeling on the barrier layer surface. The adhesive consists of a main agent and a curing agent. The main agent is sebacic acid, isophthalic acid, terephthalic acid, octanedioic acid, nonanedioic acid, undecanedioic acid, carboxylic acid containing palmitic acid, ethylene glycol, hexanediol, diethylene glycol. The curing agent is composed of glycols such as trimethylolpropane, propylene glycol, dipropylene glycol glycerin, 1,3-butanediol, isocyanates such as TDI, TDA, and the like.

In the laminated body of the present invention, the dry lamination adhesive for bonding each layer on the inner layer side with respect to the barrier layer has the above composition. However, when dry lamination is performed on the outer side of the barrier layer, a normal adhesive may be used.

As a method of laminating the laminate of the present invention, in the case of a three-layer structure, as a method of laminating the laminate of the present invention, typically, the following three methods:
1) As a first base material, a second base material laminate composed of an outer layer / barrier layer laminate and an inner layer is prepared and heat-laminated, respectively. 2) An outer layer / barrier layer as a first base material, and an inner layer as a second base material And extrusion lamination (including co-extrusion), and in this case, if necessary, the thermal lamination process is again performed. 3) Any method of laminating all by dry lamination may be used.

In the case of a four-layer configuration, the following three methods are typically used as a method of stacking:
1) Prepare a second substrate laminate composed of an outer layer / barrier layer and an intermediate layer / inner layer as the first substrate, respectively, and thermally laminate 2) Outer layer / barrier layer, second substrate as the first substrate Prepare a laminate of part of the inner layer / inner layer as the material, or only the inner layer and extrude lamination (including co-extrusion) with the intermediate layer. In this case, if necessary, repeat the thermal lamination process 3) All dry lamination Any method of pasting together may be used.

FIG. 3 shows another embodiment as a specific layer structure. The laminate, the outer layer 11 and the barrier layer 12 by dry lamination, a protective layer 15 provided on the barrier layer 12, a first substrate, a dry lamination of the intermediate layer 13 (DL-2) was 2-layer type ( 13a and 13b) , and the inner layer 14 is formed into a two-layer structure by coextrusion of 14a and 14b, and the inner layer 14 and the intermediate layer 13 are dry-laminated (DL-3) to form a second substrate. This is an example in which a thermal laminate layer TL is formed by thermal lamination with a thermal adhesive film interposed.

In the polymer battery packaging material of the present invention, the shape of the exterior body 4 may be an embossing system as shown in FIG. In this case, the bottom material 6 includes an embossed portion 8 that serves as a storage portion for the battery body, and a flange portion 9 that seals and seals the lid material 7. As shown in FIG. 2 (a), the bottom packaging material 6 is basically a four-layer laminate, and a polyester resin used for the outer layer 11 and / or the intermediate layer 13 is made of a polyethylene terephthalate copolymer or poly It is preferable to use a butylene terephthalate copolymer and reduce the draw ratio in film formation. By using the copolymer, the embossed shape of the bottom material 6 becomes sharp, and when the container is used, the opening width (T) and depth (D) shown in FIG. = 1/50 or more and the side taper θ can be 130 ° or less, and embossing is easy. When aluminum is used for the barrier layer, it is desirable that the thickness is 30 μm or more so that there is no fear of pinholes due to embossing. In the case of embossing only on one side, the lid member 7 does not need to be a copolymer because it is not molded. When embossing on both sides, a laminate of the bottom material may be used on both sides. By making the exterior body of the polymer battery an embossed type, the battery body can be stored better.

1 Polymer Battery 2 Polymer Battery Body 3 Electrode (Tab)
4 exterior body 5 heat seal part 5f back seal part 6 bottom material 7 lid material 8 embossed part 9 flange part 10 laminate (packaging material)
11 outer layer 12 barrier layer 13 intermediate layer
14 inner layer 15 protective layer 16 thermal adhesive tab material DL dry laminate layer TL thermal laminate layer

Claims (7)

A laminate type polymer battery packaging material comprising an outermost layer / barrier layer / innermost layer or an outermost layer / barrier layer / intermediate layer / innermost layer, the innermost layer being a resin that can be thermally bonded to a metal A laminate comprising at least two or more coextruded resin layers formed by a coextrusion method including layers. It is a laminate type polymer battery packaging material composed of an outermost layer / barrier layer / innermost layer or outermost layer / barrier layer / intermediate layer / innermost layer, and the innermost layer does not thermally bond to metal. A laminate comprising at least two or more coextruded resin layers formed by a coextrusion method including a resin layer that can be thermally bonded between the innermost layers. The resin capable of being thermally bonded to the metal is acid-modified polyolefin, acid-modified polyethylene, ethylene / acrylic acid copolymer, metal ion-crosslinked polyethylene, copolymer of ethylene or propylene and acrylic acid derivative, or methacrylic acid derivative. The laminate according to claim 1, comprising at least one of a product and a modified product thereof. The said barrier layer consists of aluminum 15 micrometers or more in thickness, The laminated body in any one of Claims 1-3 characterized by the above-mentioned. The intermediate layer is at least one layer of a polyester, polyolefin, fluororesin, saponified ethylene / vinyl acetate copolymer, or a resin formed from a modified product and a mixture thereof having a thickness of 10 μm or more. The laminate according to any one of claims 1 to 4, wherein the laminate is contained. On the innermost surface side of the barrier layer, epoxy, phenol, melamine, alkyd, polyimide, unsaturated polyester, polyurethane, unsaturated carboxylic acid graft polymer, polyethylene terephthalate copolymer, polybutylene Copolymer polyesters such as terephthalate copolymer, metal ion crosslinked polyethylene, ethylene / vinyl acetate copolymer, copolymer of ethylene and acrylic acid and methacrylic acid, resin such as polyether urethane, and these The laminate according to any one of claims 1 to 5, wherein a protective layer comprising a resin layer containing 30% or more of at least one of the modified product is formed. The packaging material for polymer batteries using the laminated body in any one of the said Claims 1-6.

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