TWI600736B - Polyurethane adhesive of packing material for battery,packing material for battery,container for battery and battery - Google Patents

Description

Polyurethane adhesive for battery packaging materials, battery packaging materials, Battery container and battery

The present invention relates to a polyurethane adhesive for a battery packaging material for forming a battery container or a battery package. Further, the present invention relates to a battery packaging material which is laminated using a polyurethane sealing material for a battery packaging material. Moreover, the present invention relates to a battery container in which the battery packaging material is molded, and a battery including the battery container.

Due to the rapid development of electronic devices such as mobile phones and portable computers, the demand for secondary batteries such as lightweight and small-sized lithium ion batteries has increased. As the exterior body of the secondary battery, a metal can is used in the past, but from the viewpoint of weight reduction or productivity, a packaging material such as a laminated plastic film or a metal foil has gradually become mainstream. As the most simple packaging material, as shown in FIG. 1, the outer layer side resin film layer (11), the outer layer side adhesive layer (12), the metal foil layer (13), and the inner layer are sequentially laminated from the outer layer side. A laminate of a side adhesive layer (14) and an inner surface layer (15) including a heat seal layer or the like. As a battery container, for example, as shown in FIG. 2, there is an outer layer side resin film layer (11). The convex material and the inner surface layer (15) form a concave surface to form a packaging material (draw molding processing, protrusion molding processing, etc.). The battery is sealed by sealing an electrode or an electrolytic solution or the like on the concave side of the battery container to produce a battery.

As a packaging material for a battery, a packaging material for a battery container in which an outer layer side heat-resistant resin stretched film layer, an inner layer side laminated thermoplastic resin unstretched film layer, and an aluminum foil layer are laminated between the two films is disclosed. By using a specific adhesive layer between the thermoplastic resin unstretched film layer and the aluminum foil layer, it is possible to provide a packaging material for a battery case having excellent moldability (Patent Document 1).

In addition, as a packaging material for a battery, a battery outer casing in which at least a base material layer, an aluminum foil layer, and a thermal adhesive resin layer are laminated in this order is provided, and a loop stiffness of a specific range is used, and a thickness of 80 μm or more is used. The annealed aluminum is used as an aluminum foil layer to obtain a packaging material having excellent moldability, and a lithium ion battery having a safety performance can be provided by the above packaging material (Patent Document 2).

In addition, as an adhesive for forming a laminate for non-food products such as shampoo, it is disclosed that the organic polyol having a glass transition temperature of 40 ° C or higher is contained in an amount of 5 to 50% by weight and the glass transition temperature is less than 40 ° C. An adhesive of a mixture of 95% by weight to 50% by weight of an organic polyol (which does not have a carboxyl group in its molecule) (Patent Document 3).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-92703

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-251342

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2001-322221

In recent years, with the expansion of applications such as in-vehicle or household power storage, it is required to increase the capacity of secondary batteries, and it is required to have good moldability for battery packaging materials. In addition, the secondary battery for in-vehicle or household power storage is installed outdoors, and the long-term durability is required, and the adhesion strength between the layers of each plastic film or metal foil of the packaging material is required to be high after the long-term durability test, and the appearance is also high. There is no abnormality.

The present invention has been made in view of the above circumstances, and it is an object of the invention to provide a battery having excellent moldability, high adhesion strength between layers after long-term durability test, and excellent appearance, battery container, battery packaging material, and battery packaging material. Use a polyurethane binder.

In view of the above problems, the present invention relates to an adhesive comprising a polyol component (A) comprising a polyester polyol (A1) having a different glass transition temperature and a polyester polyol (A2) in a specific ratio. The hydroxyl component of the polyurethane is formed to contain a reactive functional group relative to the above polyol component (A), and a relatively large amount of the isocyanate component is used as a curing agent.

That is, the present invention relates to a polyurethane adhesive for a battery packaging material comprising a main component and a polyisocyanate curing agent, characterized in that the main component contains a polyol component (A) and a decane coupling agent. (B) The polyol component (A) comprises a polyester polyol (A2) 95 having a glass transition temperature of 40 ° C or more and a polyester polyol (A1) of 5 to 50% by weight and a glass transition temperature of less than 40 ° C. Weight%~ 50% by weight, the equivalent ratio of the isocyanato group contained in the above polyisocyanate curing agent to the total of the hydroxyl group and the carboxyl group derived from the above polyol component (A) [NCO] / ([OH] + [COOH]) It is 10~30.

The polyurethane adhesive for a battery packaging material of the present invention preferably further contains a compound (C) which can react with a carboxyl group.

Further, the present invention relates to a battery packaging material which sequentially laminates an outer layer side resin film layer (11), an outer layer side adhesive layer (12), a metal foil layer (13), and an inner layer side adhesive layer (14). And the inner layer (15), wherein the outer layer side adhesive layer (12) is formed of the polyurethane packaging material for the battery packaging material.

Further, the present invention relates to a battery container which is formed by molding the battery packaging material, and the outer layer side resin film layer (11) constitutes a convex surface, and the inner surface layer (15) constitutes a concave surface.

Moreover, the present invention relates to a battery which is formed using the above container for a battery.

[Effects of the Invention]

According to the present invention, it is possible to provide a battery, a battery container, a battery packaging material, and a polyurethane packaging material for a battery having excellent moldability and long-term durability test and having high adhesion strength and excellent appearance. The excellent effect of the subsequent agent. A battery for sequentially laminating an outer layer side resin film layer (11), an outer layer side adhesive layer (12), a metal foil layer (13), an inner layer side adhesive layer (14), and an inner surface layer (15) In the packaging material, in order to form the outer layer side adhesive layer, by using the polyurethane adhesive of the present invention, it is possible to provide excellent adhesion between layers and to form a film without breaking during molding. A battery packaging material which is excellent in the above-described performance after the crack test and the molded portion are not raised and has a durability test. By using the battery container made of the battery packaging material described above, it is possible to provide a battery excellent in reliability.

(11) ‧‧‧ outer layer resin film

(12) ‧‧‧Outer side adhesive layer

(13)‧‧‧metal foil layer

(14) ‧‧‧Inner layer of adhesive layer

(15) ‧ ‧ inner layer

Fig. 1 is a schematic cross-sectional view showing one embodiment of a battery packaging material of the present invention.

Fig. 2 is a schematic perspective view showing one embodiment of the battery container of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. In the present specification, the description of "arbitrary number A to arbitrary number B" is a range of the index A and the number A, and the number B and the range of less than the number B.

The polyurethane adhesive of the present invention is used to form a battery packaging material for obtaining a battery container. Fig. 1 is a schematic cross-sectional view showing one embodiment of a battery packaging material according to the present invention, and Fig. 2 is a schematic perspective view showing one embodiment of the battery container of the present invention. The shape of the battery container is not particularly limited, and may be, for example, a cylindrical shape (cylinder, square tube, elliptical tube, etc.) other than the tray shape as shown in FIG. 2 . These battery containers are obtained by molding a battery packaging material in a flat state. The inner side of the battery container, that is, the surface in contact with the electrolytic solution is the inner surface layer (15). As a preferable example of the inner surface layer (15), a heat seal layer is mentioned. By using the heat seal layer, the inner surface layer (15) of the flange portion and the inner surface layer (15) constituting the battery packaging material or the inner surface layer of the flange portion of the other battery container ( 15) Opposite, contact, Heating is performed whereby the inner surface layers (15) are fused to each other to enclose the electrolyte.

The battery container is provided with a metal foil (13). In a battery container, usually The side of the metal foil (13) is referred to as "inside", the inner layer is referred to as "inner layer", the side away from the electrolyte is referred to as "outside", and the outer layer is referred to as "outside". "Outer layer." Therefore, in the predetermined battery packaging material for forming the battery container, the predetermined side located near the electrolyte solution is referred to as "inside" and the inner layer is referred to as "inside". The layer is referred to as "outside" on the predetermined side away from the electrolyte, and the outer layer is referred to as the "outer layer". The polyurethane-based adhesive of the present invention is suitable for use as a laminate (bonding) of the outer layer side resin film layer (11) and the metal foil layer (13).

The polyurethane-based adhesive of the present invention uses a main agent and a hardener By. The so-called two-liquid mixing type adhesive in which the main component and the curing agent are mixed at the time of use may be a one-liquid type adhesive in which the main agent and the curing agent are mixed in advance. Moreover, it is also possible to mix a plurality of main agents and/or a plurality of hardeners at the time of use.

The polyurethane-based adhesive of the present invention contains the polyol component (A) and Decane coupling agent (B). The polyol component (A) comprises a polyester polyol (A1) having a glass transition temperature of 40 ° C or higher and 5 to 50% by weight and a polyester polyol (A2) having a glass transition temperature of less than 40 ° C, 95% by weight to 50% by weight. %. The polyol component (A) may further contain a polyol other than the polyester polyol (A1) or the polyester polyol (A2) within a range that satisfies the object and effect of the present invention.

The polyester polyol (A1) having a glass transition temperature of 40 ° C or higher and the polyester polyol (A2) having a glass transition temperature of less than 40 ° C, for example, m-xylylene Acid, terephthalic acid, naphthalene dicarboxylic acid, phthalic anhydride, adipic acid, sebacic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic acid An acid anhydride, maleic anhydride, itaconic anhydride, an ester compound thereof, and the like (collectively referred to as a polybasic acid component), alone or in combination with, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, trimethylolpropane, glycerin, 1,9-nonanediol, 3- Methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyalcohol, etc. (collectively referred to as polyol components) It is obtained by reaction alone or in a mixture.

In addition, as a polyester polyol (A1), polyester polyol (A2) As a preferred example, a polyester urethane polyol can be exemplified by reacting the above polybasic acid component with the above polyol component to obtain a polyester polyol, and the obtained polyester polyol and, for example, 2,4-toluene Diisocyanate, 2,6-toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane A polyisocyanate such as a diisocyanate is obtained by a reaction.

In addition, as a polyester polyol (A1), polyester polyol (A2) A preferred example is a polyester polyol having a carboxyl group in a molecule (inside or at a molecular end), which is obtained by reacting the above polybasic acid component with the above polyol component to obtain a polyester polyol, and obtaining the obtained polyester polyol. The alcohol is obtained by reacting a polybasic acid such as phthalic acid, trimellitic acid or pyromellitic acid with an acid anhydride thereof.

In the polyol component (A) contained in the main component, the glass transition temperature is The polyester polyol (A1) at 40 ° C or higher is set to 5 wt% to 50 wt%, preferably 10 wt% to 40 wt%, and the polyester polyol (A2) having a glass transition temperature of less than 40 ° C is set to 95. The weight % to 50% by weight, preferably 90% by weight to 60% by weight, whereby the adhesion strength between the layers of the outer layer side resin film layer (11) and the metal foil layer (13) can be improved, and a battery having good moldability can be obtained. Use packaging materials. By setting the polyester polyol (A1) at 40° C. or higher to 5% by weight or more and the polyester polyol (A2) having a glass transition temperature of less than 40° C. to 95% by weight or less, sufficient moldability can be obtained. . In addition, the polyester polyol (A1) having a glass transition temperature of less than 40° C. is 50% by weight or more, and the polyester polyol (A2) having a glass transition temperature of less than 40° C. is 50% by weight or more. The bonding strength between the layers of the outer layer side resin film layer (11) and the metal foil layer (13).

As a polyester polyol (A1) having a glass transition temperature of 40 ° C or higher, and The molecular weight of the polyester polyol (A2) having a glass transition temperature of less than 40 ° C, particularly the number average molecular weight, is preferably from 5,000 to 100,000, more preferably from 10,000 to 50,000. When the packaging material for a battery is industrially produced, the long state is taken up in a roll shape. Further, in order to sufficiently cure the adhesive layer in the laminated body wound in a roll shape, it is aged for several days in a warehouse maintained at a high temperature. When the number average molecular weight of the polyester polyol (A1) or the polyester polyol (A2) is less than 5,000, the cohesive force of the adhesive layer which is in the middle of hardening before aging is low, and thus the appearance of occurrence of slippage or bulging in the coiled state occurs. Worries such as poor processing. On the other hand, when the number average molecular weight of the polyester polyol (A1) or the polyester polyol (A2) exceeds 100,000, the solubility in the diluted solvent becomes insufficient, and the viscosity at the time of application of the adhesive becomes high. And the coating is becoming scarce worry.

Glass transition temperature of polyester polyol (A1) and polyester polyol (A2) The measurement was carried out using a Differential Scanning Calorimeter (DSC) "RDC220" manufactured by Seiko Instruments. About 10 mg of polyester polyol (A1) and polyester polyol (A2) were separately weighed into an aluminum pan and placed in a DSC apparatus and cooled to -100 ° C by liquid nitrogen, according to 10 ° C / The glass transition temperature was calculated from the DSC chart obtained by heating the min. When the polyester polyol (A1) or the polyester polyol (A2) is dissolved in a solvent, the solvent is distilled off, dried, and subjected to DSC measurement.

The number average molecular weight of the polyester polyol (A1) and the polyester polyol (A2) is a polystyrene-equivalent value by Gel Permeation Chromatography (GPC). For example, the temperature of the column (KF-805L, KF-803L, and KF-802 manufactured by Showa Denko Co., Ltd.) is set to 40 ° C, and Tetrahydrofuran (THF) is used as the elution solution, and the flow rate is set to 0.2 mL/min. The detection was performed as RI, and the sample concentration was set to 0.02%, and polystyrene was used as a standard sample. The number average molecular weight of the present invention describes the value measured by the above method.

As the polyol component (A) contained in the main component, it is also possible to use a glass to transfer temperature A polyester polyol (A1) having a degree of 40 ° C or higher and a polyol other than the polyester polyol (A2) having a glass transition temperature of less than 40 ° C. For example, a low molecular polyol such as ethylene glycol or trimethylolpropane, a polyether polyol, a polycarbonate polyol, a polyolefin polyol, an acrylic polyol, or two of them may be used alone or in combination. Above and organic The polyurethane urethane polyol obtained by the reaction of the isocyanate can be used to such an extent that it does not adversely affect the strength or moldability.

From the viewpoint of improving the adhesion strength to metal materials such as metal foils The polyurethane adhesive of the present invention comprises a decane coupling agent (B). Examples of the decane coupling agent (B) include a trialkoxysilane having a vinyl group such as vinyltrimethoxydecane or vinyltriethoxysilane; 3-aminopropyltriethoxydecane, N -Trialkyloxydecane having an amine group such as (2-aminoethyl) 3-aminopropyltrimethoxydecane; 3-glycidoxypropyltrimethoxydecane, 2-(3,4- A trialkoxydecane having a glycidyl group such as epoxycyclohexyl)ethyltrimethoxydecane or 3-glycidoxypropyltriethoxydecane. These may be used individually or in combination of two or more types arbitrarily. The amount of the decane coupling agent (B) to be added is preferably from 0.1 part by weight to 5 parts by weight, more preferably from 0.5 part by weight to 3 parts by weight, per 100 parts by weight of the solid component of the polyol component (A). When the amount of the decane coupling agent (B) added is less than 0.1 part by weight, the effect of improving the adhesion strength to the metal foil due to the addition of the decane coupling agent is lacking, and even if 5 parts by weight or more is added, the above performance cannot be expected. improve.

In order to maintain the strength of the adhesion after the durability test, or to more effectively suppress the cause The appearance of the film is poor, and the polyurethane (5) which can react with a carboxyl group can be further used for the polyurethane adhesive of the present invention. The compound (C) which can be reacted with a carboxyl group may be contained in the main component or may be contained in the hardening agent, and may also be added when the main agent and the hardener are mixed. The compound (C) which can react with a carboxyl group is preferably a compound having a glycidyl group in the molecule, or a compound having a carbodiimide group, or A compound having an oxazoline group. By using the compound (C) reactive with a carboxyl group, it reacts with a carboxylic acid generated by decomposition of an ester bond in the adhesive layer in the long-term durability test, thereby suppressing a decrease in cohesive force due to a decrease in molecular weight of the adhesive layer. And suppressing the decrease in the strength of the subsequent or the occurrence of poor appearance.

Examples of the compound having a glycidyl group in the molecule include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a brominated bisphenol A type epoxy resin, and a hydrogenated bisphenol. A type epoxy resin, biphenol type epoxy resin, bixylenol type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, brominated phenol novolak type epoxy resin, double Phenolic A phenolic epoxy resin, trishydroxyphenylmethane epoxy resin, tetraphenol ethane epoxy resin, phenol novolak epoxy resin containing naphthalene skeleton, and dicyclopentadiene skeleton a glycidyl ether compound such as a phenol novolak type epoxy resin; a glycidyl ester compound such as diglycidyl terephthalate; and an alicyclic epoxy resin such as EHPE-3150 manufactured by DAICEL CHEMICAL INDUSTRIES; Heterocyclic epoxy resin such as triglycidyl isocyanurate; glycidylamine such as N, N, N', N'-tetraglycidyl metaxylene diamine; or (meth)acrylic acid shrinkage Glycerides and having ethylenically unsaturated double bonds a copolymer of a compound or the like. These may be used alone or in combination of two or more.

Examples of the compound having a carbodiimide group in the molecule include N,N'-di-o-tolylcarbenylcarbodiimide, N,N'-diphenylcarbodiimide, and N. N'-di-2,6-dimethylphenylcarbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-di Octyl decyl carbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,2-di-t-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N,N'-di-p-nitro Phenyl carbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di - cyclohexylcarbodiimide, and N,N'-di-p-tolylcarbenylcarbodiimide.

Examples of the compound having an oxazoline group in the molecule include 2-oxazoline, 2-methyl-2-oxazoline, 2-phenyl-2-oxazoline, and 2,5-dimethyl- a monooxazoline compound such as 2-oxazoline or 2,4-diphenyl-2-oxazoline, 2,2'-(1,3-phenylene)-bis(2-oxazoline), 2,2'-(1,2-Extended ethyl)-bis(2-oxazoline), 2,2'-(1,4-butylene)-bis(2-oxazoline), 2, 2'-(1,4-phenylene)-bis(2-oxazoline) and the like.

The compound (C) which can react with a carboxyl group is preferably a bisphenol type epoxy compound, and preferably a bisphenol type epoxy resin having a number average molecular weight of 400 to 5,000. When the number average molecular weight of the epoxy resin is less than 400, the adhesive layer tends to be soft and sufficient durability cannot be obtained. When the number average molecular weight of the epoxy resin is more than 5,000, the compatibility with the polyester polyol is lowered, and there is a concern that the appearance is poor. Further, the compound (C) which can react with the carboxyl group is preferably contained in an amount of from 1 part by weight to 100 parts by weight, more preferably from 5 parts by weight to 50 parts by weight per 100 parts by weight of the polyol component (A).

Further, as an adhesive application, a known additive may be blended in the main agent or the curing agent. For example, a reaction accelerator can be used. For example, a metal catalyst such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, or dibutyltinaleate; 1,8-diaza-bicyclic ( 5,4,0) undecen-7,1,5-diazabicyclo(4,3,0)nonene-5,6-dibutylamino-1,8-diazabicyclo ( 5,4,0) eleven carbon A tertiary amine such as alkene-7; a reactive tertiary amine such as triethanolamine; and one or more reaction accelerators selected from the group may be used.

In order to improve the appearance of the laminate, a known leveling agent or antifoaming agent may be formulated in the main agent. Examples of the leveling agent include polyether modified polydimethyl siloxane, polyester modified polydimethyl siloxane, aralkyl modified polymethyl alkyl siloxane, and polyester modification. Hydroxy-containing polydimethyl siloxane, polyether ester modified hydroxy-containing polydimethyl siloxane, acrylic copolymer, methacrylic copolymer, polyether modified polymethylalkyl hydrazine Oxyalkane, alkyl acrylate copolymer, alkyl methacrylate copolymer, lecithin, and the like. Examples of the antifoaming agent include those known as an anthrone resin, an anthrone solution, a copolymer of an alkyl vinyl ether, an alkyl acrylate, and an alkyl methacrylate.

The polyurethane adhesive of the present invention comprises polyisocyanate as a hardening Agent. The polyisocyanate may be in a state in which the polyisocyanate is diluted by an organic solvent, or may be in an undiluted state. Examples of the polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butene diisocyanate, and 2,3-butylene. Eicyl diisocyanate, 1,3-butene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-di Aliphatic diisocyanate such as isocyanate methyl hexanoate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate 4,4'-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, 1,4-bis(isocyanate methyl) An alicyclic diisocyanate such as cyclohexane or 1,3-bis(isocyanatemethyl)cyclohexane, isophthalic diisocyanate, p-phenylene diisocyanate, 4,4'-di Phenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate or 2,6-toluene diisocyanate or mixtures thereof, 4,4'-A An aromatic diisocyanate such as aniline diisocyanate, dianisidine diisocyanate or 4,4'-diphenyl ether diisocyanate, 1,3-xylene diisocyanate or 1,4-dimethylbenzene diisocyanate or a mixture thereof, ω, ω '-Diisocyanyl-1,4-diethylbenzene, 1,3-bis(1-isocyanato-1-methylethyl)benzene or 1,4-bis(1-isocyanate) Aromatic aliphatic diisocyanate such as -1-methylethyl)benzene or a mixture thereof, triphenylmethane-4,4',4"-triisocyanate, benzene-1,3,5-triisocyanate, toluene-2 , an organic triisocyanate such as 4,6-triisocyanate, or a polyisocyanate monomer such as an organic tetraisocyanate such as 4,4'-diphenyldimethylmethane-2,2',5,5'-tetraisocyanate, or the like Isocyanate monomer-derived dimer, trimer, biuret, allophanate, polyisocyanate having 2,4,6-oxadiazinetrione ring obtained from carbon dioxide and the above polyisocyanate monomer, For example with ethylene glycol, propylene glycol, Glycol, hexanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolpropane, cyclohexanedimethanol, An adduct of a low molecular weight polyol having a molecular weight of less than 200 such as diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol or sorbitol, or a polyester having a molecular weight of 200 to 20,000 Polyol, polyether ester polyol, polyester decylamine polyol, polycaprolactone polyol, polyvalerolactone polyol, acrylic polyol, polycarbonate polyol, polyhydroxyalkane, castor oil, polyamine An adduct of a formic acid ester or the like, etc., is preferably an organic polyisocyanate derived from an aromatic diisocyanate from the viewpoint of productivity of the packaging material and moldability.

Polyisocyanate hardener (2) in the polyurethane adhesive of the present invention The equivalent ratio [NCO]/([OH]+[COOH]) of the total of the hydroxyl group and the carboxyl group which the polyhydric alcohol group contained in the polyol component (A) contained in the main component (1), It is preferably 10 to 30, more preferably 15 to 25. That is, when the total amount of the hydroxyl group and the carboxyl group is 1 mol, and the isocyanate group is less than 10 mol, sufficient moldability cannot be obtained, and if it exceeds 30 mol, it is disadvantageous in terms of curing time, hygiene, and economy.

The packaging material for a battery of the present invention can be produced, for example, by a method generally used. For example, the outer layer side resin film layer (11) and the metal foil layer (13) are laminated using the polyurethane adhesive of the present invention to obtain an intermediate laminate. Then, the inner layer side adhesive (14) may be used to laminate the inner metal layer (13) of the metal foil layer (13) in the middle layer. Alternatively, an inner layer side laminate is used to laminate the metal foil layer (13) and the inner surface layer (15) to obtain an intermediate laminate. Then, the metal foil layer (13) of the intermediate laminate and the outer layer side resin film layer (11) can be laminated using the polyurethane adhesive of the present invention. In the former case, the polyurethane adhesive of the present invention is applied to one surface of any of the outer layer side resin film layer (11) or the metal foil layer (13), and the solvent is volatilized and then heated. The other substrate is superposed on the adhesive layer by pressing, and then aged at normal temperature or under heating to cure the adhesive layer. The amount of the layer is preferably from about 1 g/m ² to about 15 g/m ² . In the latter case, the polyurethane adhesive of the present invention may be applied to either the outer layer side resin film layer (11) or the metal foil layer (13) surface of the intermediate laminate.

When the polyurethane-based adhesive is applied to the substrate, in order to adjust the coating liquid to an appropriate viscosity, the solvent can be contained in the drying step without affecting the substrate. Examples of the solvent include ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; methyl acetate, ethyl acetate, and butyl acetate; An ester compound such as ethyl lactate or methoxyethyl acetate; an ether compound such as diethyl ether or ethylene glycol dimethyl ether; an aromatic compound such as toluene or xylene; an aliphatic compound such as pentane or hexane; A halogenated hydrocarbon compound such as methane, chlorobenzene or chloroform; an alcohol such as ethanol, isopropanol or n-butanol; or the like. These solvents may be used singly or in combination of two or more.

In the present invention, examples of the apparatus for applying the polyurethane-based adhesive include a comma coater, a dry laminator, a roll knife coater, and a mold. A coater, a roll coater, a bar coater, a gravure roll coater, a reverse roll coater, a blade coater, a gravure coater, a micro gravure coater, and the like.

The outer layer side resin film layer (11) constituting the battery packaging material of the present invention is not particularly limited, and a stretch film containing polyamide or polyester is preferably used. Further, it may be colored by a pigment such as carbon black or titanium oxide. Further, a coating agent such as a crack preventing coating agent, or an ink or the like may be applied. Further, two or more layers of the film may be laminated in advance. The thickness of the film layer is not particularly limited, but is preferably from 12 μm to 100 μm.

The metal foil layer (13) constituting the battery packaging material of the present invention is not particularly limited, and is preferably an aluminum foil layer. The thickness of the film layer is not particularly limited, but is preferably 20 μm to 80 μm. Further, it is preferred to subject the surface of the metal foil to surface treatment by a phosphate, a chromate, a fluoride, a triazine thiol compound, an isocyanate compound or the like, and by performing a surface treatment, the electrolyte solution of the battery or the battery can be suppressed. The bulging between the layers of the metal foil surface caused by the influence of the electrolyte.

The inner layer (15) constituting the packaging material for a battery of the present invention does not have Particularly preferably, it is preferably a heat-sealing layer comprising an unstretched film containing at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin-based copolymers, acid-modified substances and ionomers. . The thickness of the heat seal layer is not particularly limited, but is preferably 20 μm to 150 μm.

The adhesive for forming the inner layer side adhesive layer (14) constituting the battery packaging material of the present invention is not particularly limited, and it is preferable that the bonding strength between the metal foil layer (13) and the inner surface layer (15) is not caused by the battery. A known adhesive can be used as the electrolyte solution is lowered. For example, an adhesive obtained by combining a polyolefin resin and a polyfunctional isocyanate or an adhesive obtained by combining a polyol and a polyfunctional isocyanate may be applied onto a metal foil layer by a gravure coater or the like to dry the solvent. The inner surface layer (15) is superposed on the adhesive layer under heat and pressure, and then aged at normal temperature or under heating to bond the metal foil layer (13) to the inner surface layer (15). Alternatively, an adhesive such as acid-modified polypropylene may be melt-extruded onto the metal foil layer (13) by a T-die extruder to form an adhesive layer, and the inner surface layer (15) may be superposed on the adhesive layer. The metal foil layer (13) is bonded to the inner surface layer (15). When both the outer layer side adhesive layer (12) and the inner layer side adhesive layer (14) must be aged, the aging can be collectively performed.

The battery container of the present invention can be obtained by molding the battery packaging material described above, and the outer layer side resin film layer (11) is formed into a convex surface and the inner surface layer (15) is formed into a concave surface.

Next, the present invention will be more specifically described by way of examples and comparative examples. The % in both the examples and the comparative examples means mass%.

(Synthesis Example 1) 166.0 g of isophthalic acid and 166.0 g of terephthalic acid were charged. 85.6 g of ethylene glycol and 95.6 g of neopentyl glycol were subjected to esterification reaction at 200 ° C to 220 ° C for 6 hours, and after distilling off a specific amount of water, 0.12 g of tetraisobutyl titanate was added, and the pressure was slowly reduced. A 6-hour transesterification reaction was carried out at 1.3 hPa to 2.6 hPa and 230 ° C to 250 ° C to obtain a polyester polyol having a number average molecular weight of 20,000 and a glass transition temperature (Tg) of 60 °C. The polyester polyol was adjusted to have a nonvolatile content of 50% by ethyl acetate to obtain a polyester polyol solution (1) having a hydroxyl value of 2.71 mgKOH/g and an acid value of 0.1 mgKOH/g.

Further, the number average molecular weight and the glass transition temperature were determined by GPC and DSC by the method described above. Further, the acid value and the hydroxyl value were determined in the following manner.

<Measurement of Acid Value (AV)> About 1 g of a sample (polyester polyol solution) was accurately weighed in a stoppered conical flask, and a mixed solution of toluene/ethanol (capacity ratio: toluene/ethanol = 2/1) was added. 100 mL was dissolved. A phenolphthalein reagent was added thereto as an indicator and held for 30 seconds. Then, titration was carried out by a 0.1 N alcoholic potassium hydroxide solution until the solution appeared reddish. The acid value was determined by the following formula (unit: mgKOH/g).

Acid value (mgKOH/g) = (5.611 × a × F) / S

Among them, S: sample collection amount (g)

a: consumption of 0.1N alcoholic potassium hydroxide solution (mL)

F: titer of 0.1N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value (OHV)>Precision measurement in a conical flask About 1 g of the sample (polyester polyol solution) was added, and 100 mL of a mixed solution of toluene/ethanol (capacity ratio: toluene/ethanol = 2/1) was added and dissolved. Then, 5 mL of an acetamidine agent (25 g of acetic anhydride was dissolved in pyridine to prepare a solution having a capacity of 100 mL) was added, and the mixture was stirred for about 1 hour. A phenolphthalein reagent was added thereto as an indicator for 30 seconds. Then, titration was carried out by a 0.1 N alcoholic potassium hydroxide solution until the solution appeared reddish. The hydroxyl value was determined by the following formula (unit: mgKOH/g).

Hydroxyl value (mgKOH/g) = [{(b-a) × F × 28.25} / S] + D

Among them, S: sample collection amount (g)

a: consumption of 0.1N alcoholic potassium hydroxide solution (mL)

b: consumption of 0.1N alcoholic potassium hydroxide solution in blank experiment (mL)

F: titer of 0.1N alcoholic potassium hydroxide solution

D: acid value (mgKOH/g)

(Synthesis Example 2) 149.4 g of isophthalic acid, 149.4 g of terephthalic acid, 71.3 g of ethylene glycol, and 119.6 g of neopentyl glycol were placed, and the esterification reaction was carried out at 200 ° C to 220 ° C for 6 hours to distill off the specificity. After the amount of water, 40.4 g of sebacic acid was added, followed by an esterification reaction for 6 hours. After distilling off a specific amount of water, 0.13 g of tetraisobutyl titanate was added, and the pressure was gradually reduced, and the transesterification reaction was carried out at 1.3 hPa to 2.6 hPa and 230 ° C to 250 ° C for 6 hours to obtain a number average molecular weight of 19,800, polyester polyol having a Tg of 45 °C. Then, the polyester polyol was adjusted to have a nonvolatile content of 50% by ethyl acetate to obtain a polyester having a hydroxyl value of 2.33 mgKOH/g and an acid value of 0.5 mgKOH/g. Polyol solution (2).

(Synthesis Example 3) 83.2 g of isophthalic acid, 83.2 g of terephthalic acid, and 142.6 g of ethylene glycol were charged, and an esterification reaction was carried out at 200 ° C to 220 ° C for 8 hours to distill a specific amount of water, and then hydrazine was added. Diacid 188 g, followed by a 4 hour esterification reaction. After distilling off a specific amount of water, 0.13 g of tetraisobutyl titanate was added, and the pressure was gradually reduced, and the transesterification reaction was carried out at 1.3 hPa to 2.7 hPa and 230 ° C to 250 ° C for 3 hours to obtain a number average molecular weight of 22,000 polyester polyol having a Tg of -5 °C. The polyester polyol was adjusted to have a nonvolatile content of 50% by ethyl acetate to obtain a polyester polyol solution (3) having a hydroxyl value of 2.45 mgKOH/g and an acid value of 0.1 mgKOH/g.

(Synthesis Example 4) 132.8 g of isophthalic acid, 42.7 g of ethylene glycol, 71.8 g of neopentyl glycol, and 108.6 g of 1,6-hexanediol were charged, and the esterification reaction was carried out at 200 ° C to 230 ° C for 6 hours. After distilling off a specific amount of water, 175.2 g of adipic acid was added, followed by an esterification reaction for 6 hours. After distilling off a specific amount of water, 0.13 g of tetraisobutyl titanate was added, and the pressure was gradually reduced, and the transesterification reaction was carried out at 1.3 hPa to 2.6 hPa and 230 ° C to 250 ° C for 3 hours to obtain a polyester polyol. . In order to react about 90% of the hydroxyl group of the obtained polyester polyol with pyromellitic anhydride, 7.7 g of pyromellitic anhydride is added relative to the total amount of the polyester polyol, and the reaction is carried out at 180 ° C. 2 hours. It was confirmed by liquid chromatography that unreacted pyromellitic anhydride remained in the reaction system, and a trimenic acid anhydride-modified polyester polyol having a number average molecular weight of 18,000 and a Tg of -20 ° C was obtained. The polyester polyol modified with the pyromellitic anhydride was adjusted to have a nonvolatile content of 50% by ethyl acetate to obtain a polyester polyol having a hydroxyl value of 0.31 mgKOH/g and an acid value of 2.8 mgKOH/g. Solution (4).

(Synthesis Example 5) 132.8 g of isophthalic acid, 44.6 g of ethylene glycol, 74.8 g of neopentyl glycol, and 113.3 g of 1,6-hexanediol were charged, and the esterification reaction was carried out at 200 ° C to 230 ° C for 6 hours. After distilling off a specific amount of water, 175.2 g of adipic acid was added, followed by an esterification reaction for 6 hours. After distilling off a specific amount of water, 0.13 g of tetraisobutyl titanate was added, and the pressure was gradually reduced, and the transesterification reaction was carried out at 1.3 hPa to 2.6 hPa and 230 ° C to 250 ° C for 3 hours to obtain a polyester polyol. . 600 g of a polyester polyol solution obtained by adjusting the polyester polyol to 80% of a nonvolatile content by ethyl acetate, and 3.2 g of toluene diisocyanate was added, and the reaction was carried out at 80 ° C for 8 hours to obtain a reaction. A polyester polyurethane polyol having a number average molecular weight of 20,000 and a Tg of -10 °C. Then, the polyester polyol was adjusted to have a nonvolatile content of 50% by ethyl acetate to obtain a polyester polyol solution (5) having a hydroxyl value of 2.71 mgKOH/g and an acid value of 0.1 mgKOH/g.

[Production of main agent (1)] 60 parts of polyester polyol solution (1) (solid content: 30 g), 140 g of polyester polyol solution (3) (solid content: 70 g), and KBM-403 (decane coupler) After 1 g of the mixture, 136 g of ethyl acetate was added to obtain a main component (1) having a nonvolatile content of 30%. The total of the hydroxyl value and the acid value of the main agent (1) was about 1.56 mgKOH/g.

[Production of Main Agent (2) to Main Agent (11)] In the same manner as in the case of the main agent (1), the polyester polyol solution (1) to polyester was blended in the ratio (g) shown in Table 1. After the polyol solution (5) and the decane coupling agent shown below and the compound which can react with a carboxyl group, ethyl acetate was added so that the nonvolatile content was 30%, and the main agent (2) - the main agent was obtained. (11).

Decane coupling agent

KBM-403: 3-glycidoxypropyltrimethoxydecane (manufactured by Shin-Etsu Silicones)

KBM-903: 3-aminopropyltrimethoxydecane (manufactured by Nippon Unicar Co., Ltd.)

a component reactive with a carboxyl group

YD-012: bisphenol A type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd.)

(Manufacture of hardener)

Hardener (1): A resin solution having a solid content of 50% prepared by diluting an adduct of toluene diisocyanate with trimethylolpropane with ethyl acetate as a curing agent (1). The NCO% of the hardener (1) was 8.6%.

Hardener (2): A resin solution having a solid content of 50% prepared by diluting a trimer of hexamethylene diisocyanate with ethyl acetate as a curing agent (2). The NCO% of the hardener (2) was 8.6%.

Hardener (3): A resin solution containing 50 parts by weight of a curing agent (1) and 50 parts by weight of a curing agent (2) and a solid content of 50% is used as a curing agent (3). The NCO% of the hardener (3) was 8.6%.

(Examples 1 to 13 and Comparative Examples 1 to 4) The main component and the curing agent were blended at a ratio (g) shown in Table 2, and then ethyl acetate was added so that the nonvolatile content was 30%. A polyurethane binder is obtained. The equivalent ratio [NCO] / ([OH] + [COOH]) of the isocyanate group in the hardener to the total of the hydroxyl value and the acid value contained in the main component was determined as follows.

[NCO]/([OH]+[COOH])=[561×(NCO% of hardener)×(the amount of hardener (g) relative to 100 g of the main agent)]/[(hydroxyl value of the main agent) Total of acid values (mgKOH/g)) × 42 × 100]

On one surface of an aluminum foil having a thickness of 40 μm, the above-mentioned polyurethane adhesive was applied as a coating agent for the outer layer by a dry laminator at a coating amount of 5 g/m 2 to volatilize the solvent, and then laminated. An extended polyamine film having a thickness of 30 μm. Then, on the other surface of the obtained aluminum foil of the laminated film, the following adhesive for the inner layer was applied by a dry laminator at a coating amount of 5 g/m 2 to volatilize the solvent, and the thickness of the laminate was A 30 μm unstretched polypropylene film was then cured (aging) at 60 ° C for 7 days, and the outer layer and the inner layer were cured with an adhesive to obtain a battery packaging material.

*Beneer for the inner layer

The main agent and the hardener are prepared by adding the following main agent/hardener=100/10 by weight ratio, and toluene is added in such a manner that the non-volatile content is 30%, and the above-mentioned main agent is in the container. Tuftec M1913 (Styrene-Ethylene-Butadiene-Styrene (SEBS), manufactured by Asahi Kasei Chemicals Co., Ltd., having a styrene content of 30% by weight, Arkon P-140, a completely hydrogenated C9 resin manufactured by Arakawa Chemical Industries Co., Ltd., which has a carboxyl group content of 0.19 mmol/g, containing 11.4 carboxyl groups per molecule): 55 parts, and a softening point of 140 ° C, which is an adhesion-imparting agent (B). , no acid value): 45 parts, diluted by a mixed solvent of toluene / methyl ethyl ketone = 8 / 2 at 50 ° C The mixture was heated and stirred for 3 hours; the hardener was a 50% solid solution prepared by diluting a trimer of hexamethylene diisocyanate with toluene.

The battery packaging material obtained in the above manner was evaluated for performance according to the following evaluation method.

<Lamination strength before and after the heat and humidity resistance test> The battery packaging material was cut into a size of 200 mm × 15 mm, and the peeling speed was measured using a tensile tester in an environment of a temperature of 20 ° C and a relative humidity of 65%. T die peel test was performed at 300 mm/min. The peel strength (N/15 mm width) between the stretched polyamide film and the aluminum foil (the laminate strength before the moisture resistance test) was expressed by the average value of each of the five test pieces.

In addition, the battery packaging material was placed in a constant temperature and humidity chamber at 70 ° C and 90% RH atmosphere, and after standing for 168 hours, the battery packaging material was taken out from the constant temperature and humidity chamber, and measured in the same manner as before the test. Lamination strength (lamination strength after moisture and heat resistance test). The following four levels of evaluation were performed based on the average value of each peel strength.

◎: 6N/15mm or more (excellent in practical use)

○: 4N/15mm or more and less than 6N/15mm (practical area)

△: 2N/15mm or more and less than 4N/15mm (practical lower limit)

×: less than 2N/15mm

The above results are shown together in Table 2.

<Formability Evaluation Method> The battery packaging material was cut into a size of 80 mm × 80 mm, and used as a blank sample (formed material, raw material). For the above blank sample, a one-stage molding is performed by a straight mold having a freely variable molding height, by which no fracture of the aluminum foil occurs, or ridges between the layers and the maximum The molding height is evaluated for moldability. Further, the shape of the punch used for the mold was a square having a side of 30 mm, a corner 隅R of 2 mm, a punching shoulder R of 1 mm, and a shoulder R of 1 mm. Based on the height of the molding, the following four grades were evaluated.

◎: 6mm or more (excellent in practical use)

○: 4 mm or more and less than 6 mm (practical area)

△: 2 mm or more and less than 4 mm (practical lower limit)

×: less than 2mm

The above results are shown together in Table 2.

<Durability of Molded Article> The battery packaging material was cut into a size of 80 mm × 80 mm, and used as a blank sample (formed material, raw material). For the blank sample described above, a one-stage molding was performed by a straight mold having a freely variable molding height at a molding height of 3 mm. Then, the formed battery container was placed in a constant temperature and humidity chamber at 70 ° C and 90% RH, and allowed to stand for 168 hours. The battery container was taken out from the constant temperature and humidity chamber, and the appearance of the battery container was confirmed, and whether or not bulging occurred was evaluated. Further, the shape of the punch used for the mold was a square having a side of 30 mm, a corner 隅R of 2 mm, a punching shoulder R of 1 mm, and a shoulder R of 1 mm.

○: no uplift

×: Create a bulge

The above results are shown together in Table 2.

According to the results of Table 2, it is understood that the above hardening is carried out by using the total of the hydroxyl group and the carboxyl group derived from the polyol component (A) in the main component containing the polyol component (A) and the decane coupling agent (B). The polyurethane adhesive for battery packaging materials prepared by blending a polyisocyanate curing agent in an equivalent ratio of isocyanate groups in the range of 10 to 30, and providing a heat and humidity resistance test before and after The battery packaging material having excellent lamination strength and moldability, the polyol component (A) containing 5% by weight to 50% by weight of the polyester polyol (A1) having a glass transition temperature of 40 ° C or higher and a glass transition temperature of less than 40 The polyester polyol (A2) at °C is 95% by weight to 50% by weight. In addition, it is also known that a battery packaging material using the polyurethane adhesive for a battery packaging material described above can form a molded article having excellent durability.

Comparative Example 1 is not inferior to the examples in terms of the lamination strength before and after the moisture heat resistance test, but is in the above hardener with respect to the total of the hydroxyl group and the carboxyl group derived from the polyol component (A) in the main component. When the polyisocyanate curing agent is contained, the equivalent ratio of the isocyanate groups is too small, so the moldability is poor, and the durability of the molded article is also poor. In addition, in Comparative Example 3, the equivalent ratio of the isocyanate group in the case where the polyisocyanate curing agent is contained in the curing agent is appropriate, in the total amount of the hydroxyl group and the carboxyl group derived from the polyol component (A) in the main component. The composition ratio of the polyester polyol (A1) and the polyester polyol (A2) is also inappropriate, and thus the durability of the molded article is poor.

[Industrial availability]

The polyurethane adhesive of the present invention can be widely used as an adhesive for forming a battery container or a battery package. Especially suitable for forming lithium ion batteries, lithium ion polymer batteries, lead storage batteries, alkaline batteries, silver oxide-zinc storage A battery container for a secondary battery such as a pool, a metal air battery, a polyvalent cation battery, a condenser, or a capacitor, or an adhesive for a battery package. The polyurethane adhesive of the present invention is used for bonding a bonded body of the same or different raw materials, and for example, can be preferably used for joining a multilayered laminate of a plastic-based raw material and a metal-based raw material. Of course, it is also suitable for joining of plastic-based raw materials and joining of metal-based raw materials. The laminate obtained by using the adhesive of the present invention is excellent in moldability, high in environmental resistance, and can suppress deterioration of the adhesive strength over time, excellent long-term strong bonding strength, and excellent appearance shape even under outdoor exposure conditions. Therefore, it can also be used as a laminate of a need for formability such as a press through package (PTP) or a steel plate, or a protective wall material, a roofing material, a solar cell panel, a window material, an outdoor floor panel, a lighting protection material, An adhesive for laminates for outdoor industrial applications such as construction materials such as automobile components.

The priority of the Japanese Patent Application No. 2012-242154, filed on Nov. 1, 2012, is hereby incorporated by reference.

(11) ‧‧‧ outer layer resin film

(12) ‧‧‧Outer side adhesive layer

(13)‧‧‧metal foil layer

(14) ‧‧‧Inner layer of adhesive layer

(15) ‧ ‧ inner layer

Claims (8)

A polyurethane adhesive for a packaging material for a battery, comprising a main component and a polyisocyanate curing agent, wherein the main component comprises a polyol component (A) and a decane coupling agent (B), the plurality of The alcohol component (A) contains a polyester polyol (A1) having a glass transition temperature of 40 ° C or higher and 5 to 50% by weight and a polyester polyol (A2) having a glass transition temperature of less than 40 ° C, 95% by weight to 50% by weight. The equivalent ratio [NCO]/([OH]+[COOH]) of the isocyanato group contained in the polyisocyanate curing agent to the total of the hydroxyl group and the carboxyl group derived from the polyol component (A) is 10~ 30. The polyurethane adhesive for battery packaging materials according to claim 1, further comprising a compound (C) capable of reacting with the carboxyl group, wherein the compound (C) reactive with the carboxyl group has At least one of a glycidyl group-containing compound, a compound having a carbodiimide group and an oxazoline group. The polyurethane sealant for a battery packaging material according to claim 2, wherein the compound having the glycidyl group is a bisphenol epoxy compound. The polyurethane sealant for a battery packaging material according to the first or second aspect of the invention, wherein the polyisocyanate curing agent contains an aromatic polyisocyanate. A packaging material for a battery, which sequentially laminates an outer layer side resin film layer (11), an outer layer side adhesive layer (12), a metal foil layer (13), an inner layer side adhesive layer (14), and The inner surface layer (15) is characterized in that the outer layer side adhesive layer (12) is made of a polyurethane for a battery packaging material according to any one of claims 1 to 5. An ester binder is formed. The battery packaging material according to claim 5, wherein the outer layer side resin film layer (11) is a polyamide film and/or a polyester film, and the inner surface layer (15) is a polyolefin film. A container for a battery, which is formed by packaging a battery for a battery according to the fifth or sixth aspect of the invention, wherein the outer layer side resin film layer (11) constitutes a convex surface, and the inner surface layer (15) constitutes a concave surface. A battery using the container for a battery as described in claim 7 of the patent application.