JP7010332B2 - Battery packaging material - Google Patents

Description

The present invention relates to a packaging material for a battery, which suppresses whitening and has excellent moldability.

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material is an indispensable member for encapsulating a battery element such as an electrode or an electrolyte. Conventionally, metal packaging materials have been widely used for battery packaging, but in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes. At the same time, there is a demand for thinner and lighter weight. However, the metal packaging material for batteries, which has been widely used in the past, has a drawback that it is difficult to keep up with the diversification of shapes and there is a limit to weight reduction.

Therefore, as a packaging material for batteries that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base material layer / metal layer / heat-weldable resin layer is sequentially laminated is proposed. Has been done. Such a film-shaped packaging material for a battery is formed so that the battery element can be sealed by heat-welding the peripheral portions of the heat-welding resin layers so as to face each other with a heat seal.

Further, in recent years, from the viewpoint of preventing counterfeiting, it may be required to impart designability, distinctiveness, etc. to the appearance of the battery, and a pigment or the like is blended in the outermost layer of the battery packaging material. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-54563

As the film-shaped packaging material for a battery as described above, there is a material in which a recess is formed by molding and the battery element is accommodated in the space formed by the recess. In such a packaging material for batteries, whitening may occur in the outermost layer formed of the resin during molding, and in particular, the resin is greatly stretched at the corners formed by molding, so that whitening occurs. It is easy to occur. Further, when the layer located at the outermost layer is formed of a thermosetting resin or the like, the moldability is inferior to that of the thermoplastic resin, so that there is a problem that whitening during molding is particularly likely to occur.

A main object of the present invention is at least a laminate in which a surface coating layer, a base material layer, a metal layer, and a heat-welding resin layer are sequentially laminated, and the surface coating layer is a resin composition containing a thermosetting resin. It is an object of the present invention to provide a technique for suppressing whitening during molding and imparting excellent moldability in a packaging material for a battery formed of a cured product of a product.

The present inventor has made diligent studies to solve the above problems. As a result, at least a laminated body in which a surface coating layer, a base material layer, a metal layer, and a thermosetting resin layer are sequentially laminated is formed, and the surface coating layer is made of a cured product of a resin composition containing a thermosetting resin. In the formed packaging material for batteries, the maltens hardness measured at a load load of 1 mN by the surface indentation method of the surface coating layer is 15 N / mm ² or more, so that whitening during molding is suppressed, which is excellent. It has been found that it has good moldability. The present invention has been completed by further studies based on these findings.

That is, the present invention provides a battery packaging material and a battery according to the following aspects.
Item 1. At least, it is composed of a laminate in which a surface coating layer, a base material layer, a metal layer, and a heat-weldable resin layer are sequentially laminated.
The surface coating layer is formed of a cured product of a resin composition containing a thermosetting resin.
The surface of the surface coating layer is a packaging material for batteries having a Martens hardness of 15 N / mm ² or more measured by an indentation method under a load of 1 mN.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the surface coating layer contains at least one of a pigment and a dye.
Item 3. Item 2. The battery packaging material according to Item 1 or 2, wherein the resin composition further contains a curing accelerator.
Item 4. Item 2. The packaging material for a battery according to any one of Items 1 to 3, wherein the surface coating layer has a thickness of 0.5 to 10 μm.
Item 5. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the battery packaging material according to any one of Items 1 to 4.

According to the present invention, the resin composition comprises at least a laminated body in which a surface coating layer, a base material layer, a metal layer, and a heat-welding resin layer are sequentially laminated, and the surface coating layer contains a thermosetting resin. It is possible to provide a packaging material for a battery formed of a cured product, which suppresses whitening during molding and has excellent moldability.

It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram for demonstrating the measuring method of Martens hardness by an indentation method.

The packaging material for a battery of the present invention is composed of at least a laminated body in which a surface coating layer, a base material layer, a metal layer, and a heat-welding resin layer are sequentially laminated, and the surface coating layer is a resin containing a thermosetting resin. It is formed of a cured product of the composition, and the surface of the surface coating layer is characterized in that the maltens hardness measured by an indentation method at a load of 1 mN is 15 N / mm ² or more. Hereinafter, the battery packaging material of the present invention will be described in detail.

1. 1. Laminated structure of battery packaging material As shown in FIG. 1, in the battery packaging material of the present invention, at least a surface coating layer 1, a base material layer 2, a metal layer 4, and a heat-welding resin layer 5 are sequentially laminated. It consists of a laminated body. In the packaging material for batteries of the present invention, the surface coating layer 1 is the outermost layer, and the heat-weldable resin layer 5 is the innermost layer. That is, when the battery is assembled, the heat-weldable resin layers 5 located on the peripheral edge of the battery element are heat-welded to each other to seal the battery element, thereby sealing the battery element.

Further, in the battery packaging material of the present invention, as shown in FIG. 1, an adhesive layer 3 is provided between the base material layer 2 and the metal layer 4 as necessary for the purpose of enhancing their adhesiveness. May be. Further, as shown in FIG. 2, an adhesive layer 6 may be provided between the metal layer 4 and the heat-weldable resin layer 5 for the purpose of enhancing their adhesiveness, if necessary.

2. 2. Composition of each layer forming the packaging material for batteries [Surface coating layer 1]
In the battery packaging material of the present invention, the surface coating layer 1 is provided on the base material layer 2 and is a layer forming the outermost surface layer of the battery packaging material. The surface coating layer 1 is formed of a cured product of a resin composition containing a thermosetting resin.

<Composition of the resin composition forming the surface coating layer 1>
(Thermosetting resin)
The resin composition forming the surface coating layer 1 contains a thermosetting resin. The thermosetting resin may be any resin as long as it polymerizes when heated to form a polymer network structure and is cured. Specific examples of the thermosetting resin include epoxy resin, amino resin (melamine resin, benzoguanamine resin, etc.), acrylic resin, urethane resin, phenol resin, unsaturated polyester resin, alkyd resin, and the like.

Among these thermosetting resins, urethane resin, epoxy resin, and more preferably two-component curable urethane resin, two-component are preferable from the viewpoint of further shortening the curing time and improving moldability and chemical resistance. A curable epoxy resin, particularly preferably a two-component curable epoxy resin can be mentioned.

Examples of the two-component curable urethane resin include a combination of a polyol compound (main agent) and an isocyanate-based compound (curing agent), and as a two-component curable epoxy resin, specifically, an epoxy resin (main agent). , An acid anhydride, an amine compound, or a combination of amino resins (hardeners). Further, as the two-component curable urethane resin, a polyfunctional urethane (meth) acrylate composed of a combination of a polyfunctional (meth) acrylate (main agent) having active hydrogen and a polyisocyanate (curing agent) is also preferable.

The polyol compound used as the main agent in the two-component curable urethane resin is not particularly limited, and examples thereof include polyester polyols, polyester polyurethane polyols, polyether polyols, and polyether polyurethane polyols. These polyol compounds may be used alone or in combination of two or more.

The isocyanate-based compound used as a curing agent in the two-component curable urethane resin is not particularly limited, and is, for example, polyisocyanate, its adduct, its isocyanurate modified, its carbodiimide modified, and its alohanate modified. Examples include the body and its buretto denatured form. Specific examples of the polyisocyanate include diphenylmethane diisocyanate (MDI), polyphenylmethane diisocyanate (polymeric MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), and bis (4-isophorone diisocyanate) methane (H12MDI). , Isophorone diisocyanate (IPDI), 1,5-naphthalenedi isocyanate (1,5-NDI), 3,3'-dimethyl-4,4'-diphenylenedi isocyanate (TODI), xylene diisocyanate (XDI) and other aromatic diisocyanates. An aliphatic diisocyanate such as tramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate; alicyclic diisocyanate such as 4,4'-methylenebis (cyclohexamethylene diisocyanate), isophorone diisocyanate; 1,5-naphthalenedisocyanate (1) , 5-NDI) and the like, polycyclic aromatic diisocyanate and the like. Specific examples of the adduct body include those obtained by adding trimethylolpropane, glycol or the like to the polyisocyanate. These isocyanate compounds may be used alone or in combination of two or more.

These thermosetting resins may be crosslinkable elastomers. The crosslinkable elastomer is a thermosetting resin capable of imparting a soft segment to the cured product. For example, in the case of a two-component curable urethane resin or a two-component curable epoxy resin among the crosslinkable elastomers, the above-mentioned main agent may have a structure capable of imparting a soft segment. The crosslinkable elastomer can be used as part of the thermosetting resin used to form the layer constituting the surface coating layer 1 in order to provide the layer constituting the surface coating layer 1 with the desired hardness. can.

These thermosetting resins may be used alone or in combination of two or more. Further, the surface covering layer 1 may be formed of a plurality of layers. When the surface coating layer 1 is formed of a plurality of layers, the thermosetting resin used in each layer may be the same or different, and the type of the thermosetting resin should be provided in each layer. It may be appropriately selected according to the physical properties and the like. For example, among the layers constituting the surface coating layer 1, the layer forming the outermost layer (the outermost layer located on the opposite side to the metal layer 4) has a polycyclic aromaticity from the viewpoint of having excellent chemical resistance. Thermosetting resins having a group skeleton and / or a heterocyclic skeleton are preferably used. Specific examples of the thermosetting resin having a polycyclic aromatic skeleton include an epoxy resin having a polycyclic aromatic skeleton and a urethane resin having a polycyclic aromatic skeleton. Further, examples of the thermosetting resin having a heterocyclic skeleton include amino resins such as melamine resin and benzoguanamine resin. The thermosetting resin having these polycyclic aromatic skeletons and / or heterocyclic skeletons may be either a one-component curing type or a two-component curing type.

More specifically, the epoxy resin having a polycyclic aromatic skeleton is a reaction product of dihydroxynaphthalene and epihalohydrin; a condensate of naphthol and aldehydes (naphthol novolak resin) and a reaction product of epihalohydrin; dihydroxy. Condensate of naphthalene and aldehydes and reaction product of epihalohydrin; condensate of mono or dihydroxynaphthalene and xylylene glycols and reaction product of epihalohydrene; adduct of mono or dihydroxynaphthalene and diene compound and epihalohydrin Reaction products with; Examples thereof include reaction products of polynaphthols in which naphthols are directly coupled to each other and epihalohydrin.

Specific examples of the urethane resin having a polycyclic aromatic skeleton include a reaction product of a polyol compound and an isocyanate compound having a polycyclic aromatic skeleton.

(Curing accelerator)
The resin composition forming the surface coating layer 1 may further contain a curing accelerator. By coexisting a curing accelerator together with a thermosetting resin, the surface coating layer 1 can be cured in a short time without requiring aging under high temperature conditions at the time of production to form a layer having the above-mentioned specific hardness. can.

Here, the "curing accelerator" is a substance that does not form a cross-linked structure by itself, but promotes the cross-linking reaction of the thermosetting resin, has an action of promoting the cross-linking reaction of the thermosetting resin, and is itself. Is also a substance that may form a crosslinked structure.

The type of the curing accelerator is appropriately selected so as to satisfy the above-mentioned hardness depending on the thermosetting resin used. For example, an amidine compound, a carbodiimide compound, a ketimine compound, a hydrazine compound, a sulfonium salt, and a benzo. Examples thereof include thiazolium salts and tertiary amine compounds.

The amidine compound is not particularly limited, and is, for example, an imidazole compound, 1,8-diazabicyclo [5.4.0] undece-7en (DBU), 1,5-diazabicyclo [4.3.0] none-. Examples thereof include 5-ene (DBN) and guanidine compounds. Specific examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2,4-dimethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 1,2. -Diethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-benzyl- 2-Methylimidazole, 2,4-diamino-6- [2'-methylimidazolyl- (1)']-ethyl-S-triazine, 2,4-diamino-6- [2'-ethyl-4'-methyl Imidazolyl- (1)']-ethyl-S-triazine, 2,4-diamino-6- [2'-undecylimidazolyl] -ethyl-S-triazine, 2,4-diamino-6- [2'-methyl Imidazolyl- (1)']-ethyl-S-triazine isocyanur oxidation adduct, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-aryl-4 , 5-Diphenylimidazole and the like. These amidine compounds may be used alone or in combination of two or more.

The carbodiimide compound is not particularly limited, and is, for example, N, N'-dicyclohexylcarbodiimide, N, N'-diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide, N- [3-(. Dimethylamino) propyl] -N'
-Ethylcarbodiimide, N- [3- (dimethylamino) propyl] -N'-ethylcarbodiimide methiozide, N-tert-butyl-N'-ethylcarbodiimide, N-cyclohexyl-N'-(2-morpholinoethyl) Examples thereof include carbodiimide meso-p-toluenesulfonate, N, N'-di-tert-butylcarbodiimide, N, N'-di-p-tolylcarbodiimide and the like. These carbodiimide compounds may be used alone or in combination of two or more.

The ketimine compound is not particularly limited as long as it has a ketimine bond (N = C), and examples thereof include ketimine compounds obtained by reacting a ketone with an amine. Specific examples of the ketone include methyl ethyl ketone, methyl isopropyl ketone, methyl tertiary butyl ketone, methyl cyclohexyl ketone, diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, dipropyl ketone, dibutyl ketone, and diisobutyl ketone. Specific examples of the amine include aromatic polyamines such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, m-xylylene diamine, diaminodiphenylmethane, diaminodiphenylsulphon, and diaminodiethyldiphenylmethane; ethylenediamine. , Propylene diamine, butyrenidamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, 1,2-propanediamine, iminobispropylamine, methyliminobispropylamine, etc. Aliphatic polyamines; monoamines having an ether bond in the main chain such as N-aminoethylpiperazine and 3-butoxyisopropylamine and diamines having a polyether skeleton; isophoronediamine, 1,3-bisaminomethylcyclohexane, 1-cyclohexylamino-3. -Alicyclic polyamines such as aminopropane, 3-aminomethyl-3,3,5-trimethylcyclohexylamine: diamines having a norbornan skeleton; polyamide amines having an amino group at the molecular end of polyamide; 2,5-dimethyl-2, Specific examples thereof include 5-hexamethylenediamine, mensendiamine, and 1,4-bis (2-amino-2-methylpropyl) piperazine. These ketimin compounds may be used alone or in combination of two or more.

The hydrazine compound is not particularly limited, and examples thereof include dihydric acid dihydrazide and dihydrazide isophthalic acid. These hydrazine compounds may be used alone or in combination of two or more.

The sulfonium salt is not particularly limited, and is, for example, 4-acetophenyldimethylsulfonium hexafluoroantimonate, 4-acetophenyldimethylsulfonium hexafluoroarsenate, dimethyl-4- (benzyloxycarbonyloxy) phenylsulfonium hexafluoroantimote. Alkyl sulfonium salts such as Nate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroarsenate; benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, benzyl-4-methoxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxy Benzyl sulfonium salt such as phenylmethyl sulfonium hexafluorophosphate; dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophospha, dibenzyl-4-methoxyphenylsulfonium hexafluoroantimonate, benzyl- Dibenzylsulfonium salts such as 4-methoxybenzyl-4-hydroxyphenylsulfonium hexafluorophosphate; p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimo Examples thereof include substituted benzyl sulfonium salts such as nate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-chlorobenzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroantimonate and the like. These sulfonium salts may be used alone or in combination of two or more.

The benzothiazolium salt is not particularly limited, and for example, 3-benzylbenzothiazolium hexafluoroantimonate, 3-benzylbenzothiazolium hexafluorophosphate, 3-benzylbenzothiazolium tetrafluoroborate, and the like. 3- (p-methoxybenzyl) benzothiazolium hexafluoroantimonate, 3
Benzylbenzothiazolium salts such as -benzyl-2-methylthiobenzothiazolium hexafluoroantimonate and 3-benzyl-5-chlorobenzothiazolium hexafluoroantimonate can be mentioned. These benzothiazolium salts may be used alone or in combination of two or more.

The tertiary amine compound is not particularly limited, and for example, trimethylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine, 1,4-diazabicyclo [2.2.2] octane, quinuclidine, 3-quinuclidinol and the like. Examples of aliphatic tertiary amines; aromatic tertiary amines such as dimethylaniline; heterocyclic tertiary amines such as isoquinoline, pyridine, colisine, and betapicolin. These tertiary amine compounds may be used alone or in combination of two or more.

A suitable example of the curing accelerator is one that functions as a thermal acid generator. The thermal acid generator is a substance that generates acid by heating and functions as a curing accelerator. Among the above-mentioned curing accelerators, those capable of functioning as a thermal acid generator specifically include sulfonium salts, benzothiazolium salts and the like.

Further, as another suitable example of the curing accelerator, the thermal potential is activated under predetermined heating conditions (for example, 80 to 200 ° C., preferably 100 to 160 ° C.) to promote the crosslinking reaction of the thermosetting resin. Those with sex can be mentioned. Among the above-mentioned curing accelerators, examples of the heat latent substance include epoxy adducts in which an epoxy compound is added to an amidine compound, a hydrazine compound, a tertiary amine compound or the like.

Further, as another preferable example of the curing accelerator, it does not function as a curing agent in a closed state, that is, in a moisture blocking state, but the sealed state is opened and hydrolyzed under the presence of moisture to obtain a curing agent. Some have a functioning hydrolyzed potential. Among the above-mentioned curing accelerators, examples of the hydrolyzable latent substance include epoxy adducts in which an epoxy compound is added to an amidine compound, a hydrazine compound, a tertiary amine compound or the like.

These curing accelerators may be used alone or in combination of two or more. Among these curing accelerators, an amidine compound, a sulfonium salt, and more preferably an amidine compound can be mentioned.

These curing accelerators may be used alone or in combination of two or more in the surface coating layer 1. Further, when the surface coating layer 1 is formed of a plurality of layers, the curing accelerator used in each of the layers constituting the surface coating layer 1 may be the same or different, and the curing accelerator may be used. The type may be appropriately selected according to the function and physical properties to be provided in each layer.

When a curing accelerator is used, the content of the curing accelerator in the resin composition used for forming the surface coating layer 1 is appropriately set according to the type of the thermosetting resin used, the type of the curing accelerator, and the like. However, for example, the total amount of the curing accelerator is 0.01 to 6 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the thermosetting resin. The department is mentioned.

(Pigments / dyes)
The surface coating layer 1 may contain at least one of a pigment and a dye, if necessary. When the surface coating layer 1 contains at least one of a pigment and a dye, whitening during molding can be more effectively suppressed, and wear resistance can be improved. Further, since the surface coating layer 1 contains at least one of the pigment and the dye, the packaging material for the battery can be given distinctiveness (colored by at least one of the pigment and the dye), and the surface of the packaging material for the battery is matte. It is possible to impart a design and further increase the thermal conductivity of the packaging material for batteries to improve heat dissipation.

The material of the pigment is not particularly limited and may be either an inorganic pigment or an organic pigment. Specific examples of the inorganic pigment include carbon black, carbon nanotube, graphite, talc, silica, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, and oxidation. Examples thereof include magnesium, aluminum oxide, neodium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, gold, aluminum, copper and nickel. Specific examples of the organic pigment include azo pigments, polycyclic pigments, lake pigments, fluorescent pigments and the like. These pigments may be used alone or in combination of two or more.

The shape of the pigment is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape. The average particle size of the pigment is not particularly limited, and examples thereof include 0.01 to 3 μm, preferably 0.05 to 1 μm. The average particle size of the pigment is determined by using the Shimadzu laser diffraction type particle size distribution measuring device SALD-2100-WJA1 and using compressed air to inject the powder to be measured from the nozzle and disperse it in the air. It is a value measured by a jet-type dry measuring method to be measured.

If necessary, the surface of the pigment may be subjected to various surface treatments such as an insulating treatment and a highly dispersible treatment (resin coating treatment).

The type of dye is not particularly limited as long as it can be dissolved and dispersed in the resin composition used for forming the surface coating layer 1, but for example, nitro dye, azo dye, stillben dye, carponium dye, and the like. Examples thereof include quinoline dyes, methine dyes, thiazole dyes, kineimine dyes, anthraquinone dyes, indigoid dyes, and phthalocyanine dyes, and preferred examples include azo dyes, carponium dyes, and anthraquinone dyes. These dyes may be used alone or in combination of two or more.

Among these pigments and dyes, from the viewpoint of further improving the heat dissipation of the battery packaging material, a pigment is preferable, an inorganic pigment is more preferable, and a carbon material such as carbon black, carbon nanotube, and graphite is particularly preferable. Carbon black is preferable.

In order to contain a pigment when the surface coating layer 1 has a multi-layer structure composed of two or more layers, the pigment and / or the dye is one of these two or more layers. It may be contained in two or more layers. After molding the packaging material for batteries, from the viewpoint of reducing the difference in color tone between the molded portion and the unmolded portion, the surface coating layer 1 is formed into a multi-layer structure composed of two or more layers. It is preferable that the above layers contain pigments and / or dyes, and it is more preferable that the surface coating layer 1 has a three-layer structure composed of three layers and all three layers contain pigments and / or dyes. ..

When a pigment and / or a dye is contained in at least one layer constituting the surface coating layer 1, the content thereof includes the type of the pigment and / or the dye used, the distinctiveness to be imparted to the battery packaging material, and the like. It may be appropriately set according to the heat dissipation property, etc., but for example, the total amount of the pigment and / or the dye is 1 to 30 mass with respect to 100 parts by mass of the thermosetting resin contained in the layer containing the pigment and / or the dye. The department is mentioned. From the viewpoint of imparting even better distinctiveness, the total amount of the pigment and / or the dye is 3 to 20 parts by mass with respect to 100 parts by mass of the thermosetting resin contained in the layer containing the pigment and / or the dye. Can be mentioned. Further, from the viewpoint of suppressing the deterioration of moldability caused by the pigment and / or the dye as well as further excellent discriminating property, the thermosetting resin contained in the layer containing the pigment and / or the dye is 100 parts by mass. The total amount of the pigment and / or the dye is 5 to 15 parts by mass.

(Other additives)
The resin composition used for forming the surface coating layer 1 includes an organic filler, a slip agent, and a solvent, if necessary, in addition to the above-mentioned components, depending on the functionality to be provided in the surface coating layer 1 and the like. , Other additives such as elastomer resin may be included.

When the surface coating layer 1 contains an organic filler or a slip agent, it imparts a slip effect to the surface of the battery packaging material of the present invention, improves moldability and processability in press molding and embossing, and is easy to operate. Can be improved.

The type of the organic filler is not particularly limited, and examples thereof include refractory nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, and benzoguanamine. The shape of the organic filler is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape.

The slip agent is not particularly limited, and may be a non-reactive slip agent or a reactive slip agent. In particular, the reactive slip agent does not easily cause bleed loss from the outermost layer constituting the surface coating layer 1, and suppresses powder blowing, set-off, and deterioration of the slip effect over time during use. Among the slip agents, a reactive slip agent is preferable because of the advantage that it can be formed.

Here, the non-reactive slip agent is a compound that does not have a functional group that chemically bonds with a thermosetting resin and can impart slip property (slip property). The reactive slip agent is a compound that has a functional group that chemically bonds with the thermosetting resin and can impart slip property (slip property).

Specific examples of the non-reactive slip agent include fatty acid amide, metal soap, hydrophilic silicone, silicone-grafted acrylic, silicone-grafted epoxy, silicone-grafted polyether, and silicone-grafted polyester. Examples thereof include block-type silicone acrylic copolymers, polyglycerol-modified silicones, and paraffins. These non-reactive slip agents may be used alone or in combination of two or more.

The type of functional group in the reactive slip agent is appropriately set according to the type of the thermosetting resin used, and is, for example, a hydroxyl group, a mercapto group, a hydrolyzable silyl group, an isocyanate group, or an epoxy group. , A polymerizable vinyl group, a (meth) acryloyl group and the like. The number of functional groups per molecule of the reactive slip agent is not particularly limited, and examples thereof include 1 to 3, preferably 1 or 2.

Specific examples of the reactive slip agent include modified silicones having the functional groups; modified fluororesins having the functional groups; fatty acid amides such as stearate amides, oleic acid amides, erucic acid amides, and ethylene bisstearic acid amides. On the other hand, a compound into which the functional group has been introduced; a metal soap into which the functional group has been introduced; paraffin into which the functional group has been introduced, and the like can be mentioned. These reactive slip agents may be used alone or in combination of two or more. Among these reactive slip agents, preferably, the modified silicone having the functional group, the fluororesin having the functional group, and the silicone-modified resin having the functional group can be mentioned. The modified silicone is, specifically, a modified silicone in which a polymer having a functional group is block-polymerized, such as a modified silicone in which an acrylic resin is block-polymerized; and a modified silicone in which an acrylate is graft-polymerized. Examples thereof include modified silicone obtained by graft-polymerizing a monomer having a functional group. Further, as the modified fluororesin, specifically, a modified fluororesin in which a monomer having a functional group is graft-polymerized, such as a fluororesin graft-polymerized by acrylate; a modified fluororesin in which an acrylic resin is block-polymerized. Examples thereof include fluororesins in which the polymer having the functional group is block-polymerized, such as resins. Further, as the silicone-modified resin, specifically, the silicone-modified acrylic resin having the functional group and having the silicone graft-polymerized, such as a silicone-modified acrylic resin in which silicone is graft-polymerized to the acrylic resin having the functional group. Examples thereof include silicone-modified resins. Further, as the modified fluororesin, specifically, a modified fluororesin in which a monomer having a functional group is graft-polymerized, such as a fluororesin graft-polymerized by acrylate; a modified fluororesin in which an acrylic resin is block-polymerized. Examples thereof include fluororesins in which the polymer having the functional group is block-polymerized, such as resins. Among these, as a particularly preferable reactive slip agent, the modified silicone in which the monomer or polymer having the functional group is polymerized at one end of the silicone; the monomer or polymer having the functional group is fluoropolymer. Examples thereof include a modified fluororesin polymerized at one end of the resin. As such modified silicones and modified fluororesins, for example, "Modiper (registered trademark) F / FS series" (manufactured by NOF CORPORATION), "Cymac (registered trademark) series" (manufactured by Toagosei Co., Ltd.) and the like are commercially available. These commercially available products can also be used.

When the slip agent is contained in the resin composition used for forming the layer forming the outermost layer in the surface coating layer 1, the content thereof is not particularly limited, but is, for example, 100 parts by mass of the thermosetting resin. On the other hand, the total amount of the slip agent is 1 to 12 parts by mass, preferably 3 to 10 parts by mass, and more preferably 5 to 8 parts by mass.

<Hardness of surface coating layer 1>
In the packaging material for batteries of the present invention, the surface of the surface coating layer formed of a cured product of a resin composition containing a thermosetting resin has a maltens hardness of 15 N as measured by an indentation method under a load of 1 mN. It is characterized by being / mm ² or more. In the packaging material for batteries of the present invention, the surface coating layer 1 has such a specific hardness, so that the surface coating layer 1 is formed of a cured product of a resin composition containing a thermosetting resin. Despite this, whitening during molding is effectively suppressed, and it has excellent moldability. From the viewpoint of more effectively suppressing whitening during molding, the hardness is preferably 18 N or more, more preferably 20 N or more. The hardness is preferably 18 N / mm ² or more, more preferably 20 N / mm ² or more. The upper limit of the Martens hardness is about 25 N / mm ² .

In the present invention, as a specific method for measuring the displacement hardness of the surface of the surface coating layer 1, as shown in FIG. 3, the direction perpendicular to the surface of the surface coating layer 1 (the surface opposite to the base material layer 2). The Vickers indenter 10 having a diamond regular square pyramid shape with a facing angle of 136 ° was pushed in, and the Martens hardness was calculated from the obtained load-displacement curve. And. For the Martens hardness, more specifically, the surface area A (mm ² ) of the pyramid-shaped depression formed by the indentation at the maximum indentation depth h of the Vickers indenter is calculated, and the test load F (N) is divided (F). / A) It is required by. The details of the method for measuring the Martens hardness of the surface of the surface coating layer 1 are as follows. Based on the indentation method, an indenter can be pressed into the surface of the surface coating layer 1 under the following specific conditions to measure the Martens hardness of the surface coating layer 1. The Martens hardness can be measured by the indentation method using a picodenter HM-500 manufactured by Fisher Instruments.
<Measurement conditions>
・ Load load 1mN
・ Load speed 1mN / 10 seconds ・ Holding time 10 seconds ・ Load unloading speed 1mN / 10 seconds ・ Indenter Vickers (face-to-face angle 136 ° at the tip of a quadrangular pyramid)
・ Measurement temperature 25 ℃

The hardness of the surface coating layer 1 can be set to the above-mentioned value by appropriately adjusting the type and amount of the thermosetting resin used for forming the surface coating layer 1. For example, the desired hardness can be set by appropriately adjusting the amount and type of the crosslinkable elastomer in the thermosetting resin used for forming the surface coating layer 1.

<Thickness of surface coating layer 1>
The thickness of the surface coating layer 1 is, for example, about 0.5 to 10 μm, preferably about 1 to 9 μm.

[Base material layer 2]
In the battery packaging material of the present invention, the base material layer 2 is a layer provided inside the surface coating layer 1. The material forming the base material layer 2 is not particularly limited as long as it has an insulating property. Examples of the material forming the base material layer 2 include polyester resin, polyamide resin, epoxy resin, acrylic resin, fluororesin, polyurethane resin, silicon resin, phenol resin, and resin films such as mixtures and copolymers thereof. Can be mentioned. Among these, polyester resin and polyamide resin are preferable, and biaxially stretched polyester resin and biaxially stretched polyamide resin are more preferable. Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, polycarbonate and the like. Specific examples of the polyamide resin include nylon 6, nylon 6,6, a copolymer of nylon 6 and nylon 6,6, nylon 6,10, polymethoxylylen adipamide (MXD6), and the like. Be done.

The base material layer 2 may be formed of one layer of resin film, but may be formed of two or more layers of resin film in order to improve pinhole resistance and insulating property. When the base material layer 2 is formed of a multi-layered resin film, the two or more resin films may be laminated via an adhesive component such as an adhesive or an adhesive resin, and the type and amount of the adhesive component used may be used. The same applies to the case of the adhesive layer 3 or the adhesive layer 6 described later. The method for laminating two or more layers of resin films is not particularly limited, and a known method can be adopted. Examples thereof include a dry lamination method and a sand lamination method, and a dry lamination method is preferable. When laminating by the dry lamination method, it is preferable to use a urethane-based adhesive as the adhesive layer. At this time, the thickness of the adhesive layer may be, for example, about 2 to 5 μm.

The thickness of the base material layer 2 is not particularly limited as long as it functions as a base material layer, and examples thereof include about 10 to 50 μm, preferably about 15 to 25 μm.

[Adhesive layer 3]
In the packaging material for a battery of the present invention, the adhesive layer 3 is a layer provided as necessary between the base material layer 2 and the metal layer 4 in order to firmly bond them.

The adhesive layer 3 is formed by an adhesive capable of adhering the base material layer 2 and the metal layer 4. The adhesive used to form the adhesive layer 3 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 3 is not particularly limited, and may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal pressure type and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 3 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolymerized polyester; Ether-based adhesives; Polyethylene-based adhesives; Epoxy resins; Phenolic resin-based resins; Polyethylene-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; Polyethylenes such as polyolefins, carboxylic acid-modified polyolefins, and metal-modified polyolefins. Resins, polyvinyl acetate resins; cellulose adhesives; (meth) acrylic resins; polyimide resins; urea resins, melamine resins and other amino resins; chloroprene rubbers, nitrile rubbers, styrene-butadiene rubbers and other rubbers; silicones Examples include system resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane-based adhesive is preferable.

The thickness of the adhesive layer 3 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include about 1 to 10 μm, preferably about 2 to 5 μm.

[Metal layer 4]
In the battery packaging material, the metal layer 4 is a layer that functions as a barrier layer for improving the strength of the battery packaging material and preventing water vapor, oxygen, light, and the like from entering the inside of the battery. Specific examples of the metal constituting the metal layer 4 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The metal layer 4 can be formed by a metal foil, metal vapor deposition, or the like, and is preferably formed of a metal foil, and more preferably formed of an aluminum foil. From the viewpoint of preventing wrinkles and pinholes from occurring in the metal layer 4 during the manufacture of battery packaging materials, for example, soft aluminum foil such as annealed aluminum (JIS A8021P-O, JIS A8079P-O) is used. It is more preferable to form.

The thickness of the metal layer 4 is not particularly limited as long as it functions as a metal layer, but can be, for example, about 10 μm to 50 μm, preferably about 20 μm to 40 μm.

Further, it is preferable that at least one surface, preferably both sides, of the metal layer 4 is subjected to chemical conversion treatment in order to stabilize adhesion, prevent dissolution and corrosion, and the like. Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of the metal layer. As the chemical conversion treatment, for example, chromium acid chromate using a chromium acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, potassium sulfate. Treatment; Phosphoric acid chromate treatment using a phosphate compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphate; amination phenol having a repeating unit represented by the following general formulas (1) to (4). Examples include chromate treatment using a polymer. In the amination phenol polymer, the repeating unit represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. May be good.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. Further, R ¹ and R ² are the same or different, respectively, and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Examples thereof include a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group is substituted. Alkyl groups can be mentioned. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different from each other. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminating phenol polymer having the repeating unit represented by the general formulas (1) to (4) is preferably, for example, 5 to 1,000,000, and more preferably about 1,000 to 20,000. preferable.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 4, a material in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate are dispersed in phosphoric acid is coated. A method of forming a corrosion resistant layer on the surface of the metal layer 4 by performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the corrosion resistant layer. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine graft acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, and polyallylamine. Alternatively, a derivative thereof, aminophenol and the like can be mentioned. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. Examples of the cross-linking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these cross-linking agents, only one kind may be used, or two or more kinds may be used in combination.

As the chemical conversion treatment, only one type of chemical conversion treatment may be performed, or two or more types of chemical conversion treatment may be performed in combination. Further, these chemical conversion treatments may be carried out by using one kind of compound alone or by using two or more kinds of compounds in combination. Among the chemical conversion treatments, chromate chromate treatment and chromate treatment in which a chromic acid compound, a phosphoric acid compound, and an amination phenol polymer are combined are preferable.

The amount of the acid-resistant film formed on the surface of the metal layer 4 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing the above chromate treatment, the chromic acid compound is contained per 1 m ² of the surface of the metal layer 4. Chromium equivalent of about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg, phosphorus compound in phosphorus equivalent of about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg, and aminoated phenol weight. It is desirable that the coalescence is contained in a proportion of about 1 mg to about 200 mg, preferably about 5.0 mg to 150 mg.

In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the metal layer 4 by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, and then the temperature of the metal layer 4 is applied. It is carried out by heating so that the temperature is about 70 ° C to 200 ° C. Further, before the metal layer 4 is subjected to the chemical conversion treatment, the metal layer 4 may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the metal layer 4.

[Heat-welded resin layer 5]
In the battery packaging material of the present invention, the heat-weldable resin layer 5 corresponds to the innermost layer, and is a layer in which the heat-weldable resin layers are heat-welded to each other when the battery is assembled to seal the battery element.

The resin component used in the heat-weldable resin layer 5 is not particularly limited as long as it can be heat-welded, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), and polypropylene. Polypropylene such as random copolymers of polyethylene (eg, random copolymers of propylene and ethylene); polyethylene-butene-propylene tarpolymers; and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, and the like. Can be mentioned. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene and the like. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable.

The carboxylic acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing the polyolefin with a carboxylic acid. Examples of the carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like.

The carboxylic acid-modified cyclic polyolefin means that a part of the monomer constituting the cyclic polyolefin is copolymerized in place of α, β-unsaturated carboxylic acid or its anhydride, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block polymerization or graft polymerization of unsaturated carboxylic acid or its anhydride. The same applies to the cyclic polyolefin that is modified with carboxylic acid. The carboxylic acid used for the modification is the same as that used for the modification of the acid-modified cycloolefin copolymer.

Among these resin components, carboxylic acid-modified polyolefin is preferable; and carboxylic acid-modified polypropylene is more preferable.

The heat-weldable resin layer 5 may be formed of one type of resin component alone, or may be formed of a blended polymer in which two or more types of resin components are combined. Further, the heat-weldable resin layer 5 may be formed of only one layer, or may be formed of two or more layers with the same or different resin components.

The thickness of the heat-weldable resin layer 5 is not particularly limited as long as it functions as a heat-weldable resin layer, but may be, for example, about 10 to 100 μm, preferably about 15 to 50 μm.

[Adhesive layer 6]
In the packaging material for batteries of the present invention, the adhesive layer 6 is a layer provided between the metal layer 4 and the heat-weldable resin layer 5 in order to firmly bond them, if necessary.

The adhesive layer 6 is formed by an adhesive capable of adhering the metal layer 4 and the heat-weldable resin layer 5. Regarding the adhesive used for forming the adhesive layer 6, the adhesive mechanism, the types of adhesive components, and the like are the same as in the case of the adhesive layer 3. Examples of the adhesive component used for the adhesive layer 6 include a polyolefin-based resin, more preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

The thickness of the adhesive layer 6 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include about 2 to 50 μm, preferably about 15 to 30 μm.

3. 3. Method for Manufacturing Battery Packaging Material The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate in which each layer having a predetermined composition is laminated can be obtained, and examples thereof include the following methods. ..

First, a laminate in which the base material layer 2, the adhesive layer 3, and the metal layer 4 are laminated in this order (hereinafter, may be referred to as “laminate A”) is formed. Specifically, the laminate A is formed by an extrusion method or a gravure coating method in which an adhesive used for forming an adhesive layer 3 is extruded onto a metal layer 4 having a surface chemical conversion treatment on the base material layer 2 or, if necessary. It can be carried out by a dry lamination method in which the metal layer 4 or the base material layer 2 is laminated and the adhesive layer 3 is cured after being applied and dried by a coating method such as a method or a roll coating method.

Next, the heat-weldable resin layer 5 is laminated on the metal layer 4 of the laminated body A. When the heat-weldable resin layer 5 is directly laminated on the metal layer 4, the resin component constituting the heat-weldable resin layer 5 is coated on the metal layer 4 of the laminated body A by a gravure coating method, a roll coating method, or the like. It may be applied according to the method. When the adhesive layer 6 is provided between the metal layer 4 and the heat-weldable resin layer 5, for example, (1) the adhesive layer 6 and the heat-weldable resin layer 5 are placed on the metal layer 4 of the laminate A. A method of laminating by co-extrusion (co-extrusion lamination method), (2) Separately, a laminate in which the adhesive layer 6 and the heat-weldable resin layer 5 are laminated is formed, and this is placed on the metal layer 4 of the laminate A. A method of laminating by a thermal lamination method, (3) an adhesive for forming an adhesive layer 6 is laminated on a metal layer 4 of a laminate A by an extrusion method, a solution-coated method of drying at a high temperature, and a baking method. A method of laminating a heat-weldable resin layer 5 previously formed into a sheet on the adhesive layer 6 by a thermal lamination method. Examples thereof include a method of laminating the laminate A and the heat-weldable resin layer 5 via the adhesive layer 6 while pouring the melted adhesive layer 6 between the resin layer 5 (sand lamination method).

Next, the surface coating layer 1 is laminated on the surface of the base material layer 2 opposite to the metal layer 4. The surface coating layer 1 can be formed, for example, by applying the above resin composition forming the surface coating layer 1 to the surface of the base material layer 2 and heat-curing it. The order of the step of laminating the metal layer 4 on the surface of the base material layer 2 and the step of laminating the surface coating layer 1 on the surface of the base material layer 2 is not particularly limited. For example, after the surface coating layer 1 is formed on the surface of the base material layer 2, the metal layer 4 may be formed on the surface of the base material layer 2 opposite to the surface coating layer 1.

As described above, the surface coating layer 1 / the base material layer 2 / the adhesive layer 3 provided as needed / the metal layer whose surface is chemically treated as needed 4 / the adhesive layer 6 provided as needed. A laminate composed of the heat-welding resin layer 5 is formed, but in order to strengthen the adhesiveness of the adhesive layer 3 and the adhesive layer 6 provided as needed, a hot roll contact type, a hot air type, and near Alternatively, it may be subjected to heat treatment such as far infrared type. Examples of the conditions for such heat treatment include 1 to 5 minutes at 150 to 250 ° C.

In the packaging material for batteries of the present invention, each layer constituting the laminated body improves or stabilizes film forming property, laminating process, suitability for secondary processing (pouching, embossing) of the final product, etc., as necessary. Therefore, surface activation treatments such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

4. Applications of Battery Packaging Materials The battery packaging materials of the present invention are used as packaging materials for sealing and accommodating battery elements such as positive electrodes, negative electrodes, and electrolytes.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is used in the battery packaging material of the present invention, with metal terminals connected to each of the positive electrode and the negative electrode projecting outward. Batteries are packaged by covering the peripheral edge of the element so that a flange portion (a region where the heat-welding resin layers come into contact with each other) can be formed, and heat-sealing and sealing the heat-welding resin layers of the flange portion. Batteries using the material are provided. When the battery element is housed using the battery packaging material of the present invention, the sealant portion of the battery packaging material of the present invention is used so as to be inside (the surface in contact with the battery element).

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

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

Examples 1-3 and Comparative Example 1-2
<Manufacturing of packaging materials for batteries>
By laminating the heat-weldable resin layer 5 on the laminate in which the base material layer 2 / the adhesive layer 3 / the metal layer 4 are laminated in this order by the thermal laminating method, the base material layer 2 / the adhesive layer 3 / the metal layer is laminated. 4 / A laminated body in which the heat-weldable resin layers 5 were laminated in order was obtained. Next, from a laminate in which a surface coating layer is formed on the surface of the substrate layer 2 and the surface coating layer 1 / substrate layer 2 / adhesive layer 3 / metal layer 4 / heat welding resin layer 5 are laminated in this order. Manufactured a packaging material for batteries. The specific manufacturing conditions for the battery packaging material are as shown below.

First, a laminated body in which the base material layer 2 / the adhesive layer 3 / the metal layer 4 were laminated in this order was produced. Specifically, an adhesive layer 3 composed of a two-component urethane adhesive consisting of a polyester-based main agent and an isocyanate-based curing agent is formed on one surface of the base material layer 2 so as to have a length of 3 μm, and the metal layer 4 is chemically treated. A laminated body in which the base material layer 2 / the adhesive layer 3 / the metal layer 4 were laminated in this order was produced by laminating the surface with pressure and heating (thermal lamination).

As the base material layer 2, a biaxially stretched nylon film having a thickness of 15 μm was used, and as the metal layer 4, a metal layer 4 made of an aluminum foil having a thickness of 35 μm was used. A treatment liquid consisting of trivalent) and phosphoric acid was applied to both sides of the metal layer by a roll coating method at 10 mg / m ² respectively, and was subjected to chemical conversion treatment by baking for 20 seconds under the condition that the film temperature was 180 ° C. or higher.

Further, separately, a heat-weldable resin layer 5 made of a layer coextruded film was prepared. Each of the heat-weldable resin layers 5 includes a resin layer constituting the metal layer side (unsaturated carboxylic acid graft-modified random polypropylene graft-modified with unsaturated carboxylic acid, thickness 20 μm) and a resin layer constituting the innermost layer side (thickness 20 μm). Polypropylene (random copolymer), thickness 15 μm) was co-extruded to obtain a two-layer co-extruded film.

Next, the metal layer of the laminate composed of the base material layer 2 / the adhesive layer 3 / the metal layer 4 produced above is overlaid so that the resin layer constituting the metal layer side of the two-layer coextruded film produced above is in contact with the metal layer. At the same time, by heating the metal layer 4 to 120 ° C. and performing thermal lamination, a laminate in which the base material layer 2 / the adhesive layer 3 / the metal layer 4 / the heat-weldable resin layer 5 are laminated in this order is obtained. rice field. The obtained laminate was once cooled, then heated to 180 ° C., maintained at that temperature for 1 minute, and heat-treated.

Next, the polyfunctional urethane acrylate obtained by reacting the polyfunctional acrylate having active hydrogen with the polyisocyanate was applied to the surface of the base material layer 2 of the laminate, and heated at 45 ° C. for 3 days. A packaging material for a battery comprising a laminated body in which a surface coating layer 1 having a thickness of 3 μm is formed and a surface coating layer 1 / base material layer 2 / adhesive layer 3 / metal layer 4 / heat-weldable resin layer 5 are laminated in this order. Obtained.

<Measurement and evaluation of hardness of surface coating layer>
The Martens hardness of the surface of the surface coating layer 1 of each battery packaging material obtained above was measured by an indentation method using Picodenter HM-500 manufactured by Fisher Instruments. The Martens hardness was taken as an average value measured 5 times with respect to the surface of the surface coating layer 1. The details of the measurement conditions are as follows. The results are shown in Table 1.
<Measurement conditions>
・ Load load 1mN
・ Load speed 1mN / 10 seconds ・ Holding time 10 seconds ・ Load unloading speed 1mN / 10 seconds ・ Indenter Vickers (face-to-face angle 136 ° at the tip of a quadrangular pyramid)
・ Measurement temperature 25 ℃
・ Relative humidity 50%

<Evaluation of moldability>
The battery packaging material obtained above was cut to prepare a strip piece having a size of 120 × 80 mm, which was used as a test sample. Using a straight mold consisting of a male mold having a rectangular shape of 30 × 50 mm and a female mold having a clearance of 0.5 mm between the male molds, the above is performed on the female mold so that the heat-adhesive resin layer side is located on the male mold side. A test sample was placed, and the test sample was pressed with a pressing pressure (surface pressure) of 0.1 MPa so that the forming depth was 6 to 8 mm, respectively, and cold forming (pull-in one-stage forming) was performed. It was visually confirmed whether or not there were pinholes in the corners of the molded battery packaging material and whether or not whitening had occurred. The results are shown in Table 1.

1 Surface coating layer 2 Base material layer 3 Adhesive layer 4 Metal layer 5 Heat-weldable resin layer 6 Adhesive layer

Claims (5)

At least, it is composed of a laminated body in which a surface coating layer (excluding those having a thickness of 4 μm or more and 12 μm or less) , a base material layer, a metal layer, and a heat-weldable resin layer are sequentially laminated.
The surface coating layer is formed of a cured product of a resin composition containing a thermosetting resin.
The surface of the surface coating layer is a packaging material for batteries having a Martens hardness of 15 N / mm ² or more (excluding 25 N / mm ² or less) measured by an indentation method under a load of 1 mN. The battery packaging material according to claim 1, wherein the surface coating layer contains at least one of a pigment and a dye. The battery packaging material according to claim 1 or 2, wherein the resin composition further contains a curing accelerator. The packaging material for a battery according to any one of claims 1 to 3, wherein the surface coating layer has a thickness of 0.5 to 10 μm (excluding those having a thickness of 4 μm or more) . A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the battery packaging material according to any one of claims 1 to 4.

Images