JP2002362617A - Package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package having a heat resistance characteristic in which ethylene resin is applied as a sealant layer and a packaging material is not deteriorated by the stored content. SOLUTION: This package comprises multilayer structure including a thermoplastic resin layer (11) and an aluminum foil layer (13). Its sealant layer (15) is a resin compound comprised of resin (A) having polyolefin resin as its base material, and ethylene copolymer (resin B and resin C) showing a certain reactive characteristic. The aluminum foil layer is processed by hydrothermal denaturation. Either isocyanate compound or its derivatives (14) are stacked on the aluminum foil processed by hydrothermal denaturation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ethylene-based resin in which the innermost sealant layer of a multilayer package comprising a thermoplastic resin layer and an aluminum foil layer is reactive with a resin A based on a polyolefin resin. A resin composition composed of a copolymer (resin B, resin C) or a resin composition composed of resin A and resin D having self-crosslinking property, and a resin composition layer having heat resistance as a sealant layer. More specifically, the package is characterized by subjecting an aluminum foil to a hot water denaturation treatment and, if necessary, laminating an isocyanate compound layer on the hot water treated aluminum foil to form a lithium (Li) battery. Heat resistance, aluminum required for highly permeable and flammable electrolytes, such as an electrolyte package or a polymer gel package impregnated with such an electrolyte. And it relates to a packaging material having adhesion to the sealant layer.

[0002]

2. Description of the Related Art In the field of packaging, when designing a packaging material that can withstand boiling or retort, the selection of a film base material, the selection of an adhesive to be used when bonding films together, or the sealant layer of a packaging material. It is necessary to select a resin to be used as the resin. Particularly, in the field of sealants, heat-resistant packaging materials are often designed by using a homo- or block-type polypropylene resin.

[0003] While the heat resistance of packaging materials for food applications such as boiling and retort sterilization has been required, in recent years, such as an electrolyte type or a polymer gel type packaging material for a lithium battery impregnated with the electrolyte, has been developed. There is an increasing need for packaging materials that require heat-resistant design in consideration of product safety.

In general, in order to design a packaging material that requires heat resistance, the above-mentioned polypropylene or the like is used in many cases. However, since it is said that the use of polypropylene causes deterioration in battery characteristics, relatively heat-resistant resins other than polypropylene, such as high-density polyethylene and high-density ethylene-α-olefin copolymer, are used. There are cases.

[0005] When designing a packaging material for a battery, it is necessary not only to design the battery so as not to degrade its characteristics, but also to guarantee the safety under the use environment. For example,
If the electrolyte leaks, there is a risk of fire. In this sense, it is necessary to design a packaging material having excellent sealing properties, and it is necessary to maintain the sealing properties even when the battery overheats and reaches an extremely high temperature higher than the usage environment. However, if it is a polypropylene resin, particularly if it is a homo-type resin, considerable heat resistance can be expected, but high-density polyethylene or a high-density ethylene-α-olefin copolymer is insufficient for the above-mentioned heat resistance. There is a need for an ethylene resin with improved properties.

Recently, in order to improve the heat resistance of a polyethylene resin, a crosslinked structure is formed by introducing a peroxide during the formation of the polyethylene resin or irradiating EB after the film is formed. In many cases, the former type using peroxide is difficult to select the peroxide and control the crosslinking reaction.In addition, regardless of the former, the crosslinked polymer has no heat sealing property For this reason, even if the heat resistance is improved, there is a problem that the heat sealability is poor.

Further, as an electrolytic solution used in a Li battery, a solution prepared by dissolving a lithium hexafluoride salt or the like in a predetermined mixing ratio in an aprotic solvent such as ethylene carbonate, propylene carbonate or ethyl methyl carbonate is used. This Li salt generates hydrofluoric acid by hydrolysis.
In order to prevent the generation of hydrofluoric acid, the packaging material for the Li battery uses an aluminum foil as an intermediate layer to impart a barrier property.
However, due to moisture absorption from the end face of the packaging material (the part where the barrier property cannot be imparted by the aluminum foil), the lithium salt is hydrolyzed, and the generated hydrofluoric acid permeates the innermost sealant layer, attacks the aluminum foil layer, and There is a problem of causing delamination at the interface between the foil and the sealant layer. As described above, the generation of hydrofluoric acid is said to penetrate from the sealing end face of the packaging material, but not only the effect of hydrofluoric acid due to the hydrolysis of the Li salt described above, but also the aprotic solvent penetrates the sealant layer. It is also said that it accumulates at the interface between the aluminum foil and the sealant, resulting in delamination.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to take into account the above-mentioned circumstances, and has heat resistance using an ethylene-based resin as a sealant, and does not cause deterioration of the packaging material due to the contents (delamination is reduced). Not happen) packaging, especially
Like a packaging material for Li batteries, a package that has heat resistance and improved adhesion between the aluminum foil and the sealant layer without being affected by the contents (hydrofluoric acid, aprotic solvents, etc.) To provide.

The present invention has been conceived to overcome the above-mentioned problems, and the invention according to claim 1 is directed to an innermost sealant layer of a package having a multilayer structure including a thermoplastic resin layer and an aluminum foil layer. Is a resin composition comprising a resin A based on a polyolefin resin and an ethylene-based copolymer (resin B and resin C) having reactivity with each other.

According to a second aspect of the present invention, there is provided an ethylene copolymer in which the innermost sealant layer of a multilayer laminate including a thermoplastic resin layer and an aluminum foil layer has a self-crosslinking property with a resin A based on a polyolefin resin. (Resin D).

According to a third aspect of the present invention, the sealant layer contains 1 to 30 wt% of (resin B + resin C) or 0 to 99 wt% of resin A based on 70 to 99 wt% of resin A.
%. The package according to claim 1, wherein the content of the resin D is 1 to 100 wt% with respect to%.

The invention according to claim 4 is characterized in that the polyolefin resin A is a high-density polyethylene resin having a density of 0.925 g / cm ³ or more, a medium-density polyethylene or ethylene-α.
The package according to any one of claims 1, 2, 3 and 4, which is any one of the olefin copolymers and a resin composition based on these.

According to a fifth aspect of the present invention, the combination of the resin B and the resin C is (resin B / resin C) = (acid-modified ethylene copolymer / epoxy-modified copolymer) or (resin B / resin C) C) = (ethylene-α, β-unsaturated carboxylic acid or its ionic crosslinked product / epoxy-modified copolymer), wherein the package according to claim 1, 3 or 4, is provided. is there.

The invention according to claim 6 is characterized in that the resin D is any one of a silane-modified ethylene-based copolymer, an isocyanate-modified ethylene-based copolymer, and an acid-modified ethylene-based copolymer. A package according to item 2, 3 or 4.

The invention according to claim 7, wherein the aluminum foil layer has been subjected to a hot water denaturation treatment, wherein the package according to claim 1, 2, 3, 4, 5 or 6 is provided.
It is what it was.

The invention according to claim 8 is characterized in that the hot water denaturation treatment is a boehmite treatment.
2, 3, 3, 5, 6, or 7.

The invention according to claim 9 is that, after laminating an isocyanate compound or a derivative thereof to a thickness of 5 μm or less on the hot water-modified aluminum foil layer, the resin composition alone or by extrusion lamination is used. The package according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein a multilayer film containing the resin composition is laminated.

The invention according to claim 10 is used as an exterior material for a Li battery, according to claims 1, 2, 3, 4, 5, 6,
7, 8 or 9.

[0019]

Embodiments of the present invention will be described below in detail. The package of the present invention is made of a thermoplastic resin, particularly a high-density polyethylene having a density of 0.925 g / cm ³ or more, a medium-density polyethylene, or an ethylene-α-olefin, in order to impart heat resistance to the innermost sealant layer. An ethylene-based copolymer (resin B, resin C) having reactivity with each other or an ethylene-based copolymer having self-crosslinking property (resin D) was blended with a polymer-based polyolefin resin (resin A). It is characterized in that the resin composition layer is used as a sealant layer.

Also, even if a highly permeable content such as an electrolytic solution used in a Li battery is filled, the interface between the aluminum foil and the multilayer film including the sealant layer is not delaminated. An aluminum foil subjected to a water denaturation treatment, particularly a boehmite treatment, is used, and an isocyanate compound or a derivative thereof having a thickness of 5 μm or less is provided on the hot water denaturation treated aluminum foil as required.

The heat-resistant sealant layer of the present invention will be described in detail. As a thermoplastic resin as a base, the melt index (MI) according to ASTM D1238 is 0.1 to 100, and more preferably 3 to 5.
0 in the range of a density of 0.925 g / cm ³ or more, more preferably 0.930 g / cm ³ or more, more preferably 0.940 g / cm ³ or more polyolefin resin or olefin-based copolymer are preferable, Medium A simple substance of a high-density polyethylene, a high-density polyethylene, an ethylene-α-olefin copolymer, or a blend thereof is preferable.

These polyolefin resins can be produced by various polymerization methods without any particular limitation on the production method. However, when producing a polyolefin resin having a density in the above-mentioned range, a solution method, a slurry method, a gas method, or the like can be used. Polyolefin resins formed by a medium-to-low pressure method such as a phase method are preferred.
Also, the catalyst required for these polymerizations is not limited to the polymerization catalyst such as a Ziegler catalyst or a metallocene catalyst. In addition, since these polyethylene resins may be inferior to extrusion lamination suitability, low-density polyethylene obtained by a high-pressure method and ethylene obtained by a medium-to-low pressure method in the sense of improving workability as necessary. A -α olefin copolymer may be blended. In addition, various additives (antioxidants, tackifiers,
Fillers, various fillers, etc.) may be added.

The point of the sealant layer of the heat-resistant packaging bag of the present invention is that the ethylene-based copolymer (resin B, Resin C) or self-crosslinkable ethylene copolymer (Resin D)
Is mixed with the above-mentioned polyethylene resin (resin A) to locally form a crosslinked structure and to form a crosslinked structure in the sealant layer to such an extent that the heat sealability is not deteriorated.

Examples of the polyethylene resins having reactivity with each other include an acid anhydride-modified polyolefin or an ethylene-α, β-unsaturated carboxylic acid or an ionic crosslinked product thereof (resin B) and an epoxy-modified polyolefin (resin C). As typical examples of the resin B, maleic anhydride grafted low density polyethylene, maleic anhydride grafted medium density polyethylene, maleic anhydride grafted high density polyethylene, maleic anhydride grafted ethylene-α-olefin copolymer, ethylene- ( (Meth) acrylic acid copolymer, ethylene- (meth) acrylic acid- (meth) acrylic acid ester copolymer, ion-crosslinked product of the ethylene- (meth) acrylic acid copolymer polymer, ethylene-maleic anhydride- ( Various choices such as (meth) acrylate copolymers And typical examples of the resin C are ethylene- (meth) acrylic acid glycidyl ester copolymer, ethylene- (meth) acrylic acid glycidyl ester-vinyl acetate copolymer, ethylene- (meth) Glycidyl acrylate- (meth) acrylate copolymer as well as the main chain copolymer type such as the above-mentioned (meth) acrylate glycidyl ester, polyethylene, ethylene-α-olefin copolymer,
A type obtained by graft-polymerizing an ethylene-vinyl acetate copolymer or an ethylene- (meth) acrylate copolymer may be used. The type of acid and the type of epoxy are not limited to (meth) acrylic acid, maleic anhydride, and glycidyl (meth) acrylate described above, and various types may be used. The combination of polymers having reactivity with each other is not limited to the acids and epoxies described above.

On the other hand, examples of the ethylene-based copolymer (resin D) having self-crosslinking properties include a type obtained by grafting vinylsilane or acrylic-based silane to polyethylene or an ethylene-based copolymer, or an isocyanate having an unsaturated bond. Examples include a type in which a nate compound is introduced into polyethylene or an ethylene-based copolymer by a graft reaction. As an example, in the silane-modified type, an ethylene-vinyltrimethoxysilane graft copolymer, an ethylene-vinyltriethoxysilane graft copolymer, an ethylene- (meth) acryloxyethyltrimethoxysilane graft copolymer, an ethylene-vinyltrimethoxysilane graft copolymer, (Meth) acryloxyethyltriethoxysilane graft copolymer, ethylene-vinyl acetate-vinyltrimethoxysilane graft copolymer, ethylene-vinyl acetate-vinyltriethoxysilane graft copolymer, ethylene-vinyl acetate- (meth)
Acryloxyethyltrimethoxysilane graft copolymer, ethylene-vinyl acetate (meth) acryloxyethyltriethoxysilane graft copolymer, ethylene- (meth) acrylate-vinyltrimethoxysilane graft copolymer, ethylene- ( (Meth) acrylic acid ester-vinyltriethoxysilane graft copolymer, ethylene- (meth) acrylic acid ester- (meth) acryloxyethyltrimethoxysilane graft copolymer, ethylene- (meth) acrylic acid ester- (meth) Acryloxyethyltriethoxysilane graft copolymer and the like can be mentioned.

On the other hand, two types of isocyanate compounds having an unsaturated bond can be selected.
One is a vinyl-based, allyl-based, (meth) acrylic-based isocyanate compound monomer having at least one functional isocyanate group, and the other is a bifunctional isocyanate monomer or adduct. Isocyanate monomer derivatives trifunctionalized in the form of styrene, burette, or isocyanurate, or polyfunctionalized to four or more functional groups, containing active hydrogen reactive with isocyanate and containing vinyl, allyl or (meth) An isocyanate compound complex having at least one functional isocyanate group, which is complexed with a compound having an unsaturated double bond such as acryl, may be mentioned. As typical isocyanate compounds of the former monomer, vinyl isocyanate, allyl isocyanate, (meth) acryloxyoxyethyl isocyanate, (meth) acryloxyoxybutyl isocyanate and the like can be used. However, it is not limited to these. Representative examples of the latter complex include isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. It is possible to use various diisocyanate-based monomers such as nathate and 4,4'-diphenylmethane diisocyanate. In addition, these diisocyanate monomers are used as adduct types, which are reacted with trifunctional active hydrogen-containing compounds such as trimethylolpropane or glycerol, burette types, which are reacted with water, and self-polymerization of isocyanate groups. A trifunctional derivative such as a trimer (isocyanurate) type or a polyfunctional derivative having a higher functionality may be used. The latter complex is formed by reacting the above isocyanate compound with a compound having an isocyanate group and having an unsaturated double bond in its structure. is necessary. Examples of the compound having reactivity with the isocyanate group and having an unsaturated double bond in its structure include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and glycerol. Mono (meth) acrylate, glycerol di (meth) acrylate, ethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, allyloxyethyl alcohol and the like can be mentioned. As the compound having an unsaturated double bond, a hydroxyl group is mainly mentioned as an active hydrogen, but a compound containing another active hydrogen group such as an amine may be used.
Further, the complex obtained from the isocyanate monomer is
Further, it may be compounded with various monomers to obtain a derivative such as an adduct type, a burette type, or an isocyanurate type. In this case, the complex is a bifunctional isocyanate compound having an unsaturated bond. The above-described isocyanate compound monomers or composites may be used alone or as a mixture. In addition, in order to control the reactivity of the isocyanate compound, the isocyanate group can be used as a block isocyanate using an oxime-based, amide-based, active methylene-based, or pyrazole-based compound as a blocking agent, Acetone oxime,
Methyl ethyl ketoxime, ε-caprolactam, dimethyl malonate, methyl acetoacetate, 3,5-dimethylpyrazole, and the like. In addition, phenol-based, alcohol-based, imidazole-based, and urea-based blocking agents are used. It is possible, and there is no particular limitation. These blocking agents may be used alone or in combination of two or more.

The above-mentioned ethylene copolymer into which a silane or isocyanate monomer has been introduced can form a crosslinking reaction in the presence of water or by heating. Instead, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid- (meth) acrylic acid ester copolymer, and these acid-based copolymers are treated with various ions such as Na ions and Zn ions. It is also possible to use crosslinked ionomer resins. Unlike the above-mentioned reactivity, these cross-linking types can form a heat-reversible cross-linking reaction such as dimerization due to carboxylic acid hydrogen bond or ionic cross-linking. For example, ionomers are preferred.

In addition, when the above-mentioned self-crosslinkable polymer is compounded, particularly, reactive types such as silane and isocyanate monomers may be prepared from polyethylene, ethylene-vinyl acetate copolymer or ethylene- (meth) acrylic acid. It may be diluted with a resin such as an ester, and when these monomers are grafted, a polymer in which another monomer is grafted in advance depending on the ease of processing may be used.

The mixing ratio of (Resin B + Resin C) to Resin A or the mixing ratio of Resin D to Resin A is as follows.
It is preferable that the resin D is 1 to 100 wt% with respect to 30 wt% or the resin A is 0 to 99 wt%. When blending the resin B and the resin C which are mutually reactive,
If the content of the resin A is less than 70% by weight, remarkable gelation due to the reaction between the resin B and the resin C causes poor appearance and a decrease in workability due to an increase in melt viscosity. In addition, resin A is 9
If the content is more than 9 wt%, heat resistance cannot be imparted because the crosslinked structure is insufficient. In addition, the latter resin D, which is a self-crosslinking ethylene copolymer, can be used as a single film, but from the viewpoint of controllability of workability and reactivity, and heat sealability after a crosslinking reaction, resin D alone can be used. It is more preferable to blend with resin A than to use it. In addition, resin A is used in an amount of 10 in terms of processability during extrusion lamination and suppression of gelation and viscosity increase due to self-crosslinking (self-reaction) at the processing temperature. Resin D to 30 to 9 wt%
A range of 0 wt% is preferred.

By using the above-mentioned resin composition as a sealant layer, while having a heat sealing property,
It is possible to improve heat resistance by forming a crosslinked structure.

On the other hand, for imparting the content resistance, it is preferable to use an aluminum foil which has been subjected to a hot water modification treatment. As the treated water for treating the aluminum foil, any of tap water, deionized water, distilled water, or distilled water distilled after deionization can be used, and in particular, deionized distilled water is preferable, and the electric conductivity is used as an index. It is preferable to use water having a temperature of 1.0 μS / cm. These treated waters contain a small amount of alkali such as ammonia or amines such as triethanolamine in an amount of 0.1 to 1%.
The addition is preferable as the hydrothermal conversion treatment. As the hydrothermal conversion process of aluminum foil, depending on the processing temperature,
Various hydrated oxide layers are formed. A particularly preferred treatment temperature in the present invention is a condition under which boehmite is formed as a hydrated oxide, and 80 to 100 ° under normal pressure.
C, more preferably in the range of 90 to 100 ° C., preferably subjected to a hot water modification treatment. Hereinafter, the hydrothermal treatment of the present invention is referred to as boehmite treatment.

The following are examples of indices for boehmite treatment of the substrate. First, when the surface of the aluminum surface or the alumina surface subjected to the boehmite treatment is measured by X-ray photoelectron spectroscopy, the spectral peak position derived from the oxide and hydroxide of aluminum (Al) 2p orbit has a binding energy of 75.4 ev or less. It is characterized by being. Al 2 obtained from X-ray photoelectron spectroscopy
In the spectrum of the p-orbital, 72.
The peak at 7 ev is a peak derived from metallic Al, and the peak near 74.0 to 76.0 ev on the high energy side is a peak derived from aluminum oxide and aluminum hydroxide. The peaks derived from aluminum oxide and aluminum hydroxide cannot be separated due to small chemical shift,
When the binding energy is 75.4 ev or less, the adhesiveness to various functional groups is more excellent.

When the surface of the aluminum surface or the alumina surface subjected to the above-described boehmite treatment is measured by X-ray photoelectron spectroscopy, the element ratio (O / Al) of oxygen (O) to aluminum (Al) is 1.7. It is characterized by the above. O / Al obtained from X-ray photoelectron spectroscopy is an index of the degree of surface oxidation of aluminum (including the oxygen of hydroxide). If the O / Al ratio is 1.7 or more, the O / Al ratio with various functional groups is high. Excellent in adhesiveness.

Further, when the surface of the aluminum surface or the alumina surface subjected to the above-described boehmite treatment was subjected to time-of-flight secondary ion mass spectrometry, the ratio (OH / O) of hydroxyl group (OH) to oxygen (O) was reduced. 0.9 or more. In the time-of-flight secondary ion mass spectrometry, the degree of oxidation and the degree of hydroxylation on the aluminum surface can be distinguished. If the ratio of OH / O is 0.9 or more, bonding using a hydroxyl group, for example, If a hydrogen bond or a reaction occurs, formation of a primary bond or the like can be expected, and the adhesiveness with various functional groups is excellent.

When the surface area ratio and the surface roughness of the aluminum surface or the alumina surface subjected to the boehmite treatment described above are measured by an atomic force microscope, the surface area ratio (the surface area of the substrate subjected to the hydrothermal denaturation treatment / The surface roughness of the treated substrate is 1.5 or more, and the average roughness of the center plane (Ra) is 15 n.
m or more, and a root mean square roughness (RMS) of 20 nm or more. The content of this is that by subjecting the untreated aluminum surface or alumina surface to boehmite treatment, the original oxide film originally decreases, crystals of hydrated oxide such as boehmite precipitate, and the hydrated oxide layer is formed. This means that the surface is significantly roughened as compared with an untreated surface, resulting in a surface with severe undulation. Therefore, the surface area is improved, and the surface roughness is also improved. As a result, when various thermoplastic resins are laminated, it is possible to improve the adhesion area, increase the number of functional groups on the boehmite-treated surface, and improve the physical adhesion by the anchoring effect.

Finally, as an index of the boehmite treatment, when a fracture surface of a substrate having an aluminum surface or an alumina surface subjected to the above-mentioned hydrothermal alteration treatment is observed by transmission electron microscope observation, The thickness of the treatment layer formed by performing the water denaturation treatment is 0.1 μm or more. The hydrothermal alteration treatment such as boehmite treatment involves forming a hydrated oxide film on the aluminum oxide layer that originally existed through various reactions. The combined aluminum oxide layer is reduced by the treatment, while its thickness increases as the hydrated oxide layer is formed. Since the treatment proceeds when the hydrated oxide layer is formed to some extent, the binding energy and O / A
It is possible to make the 1 ratio and the OH / O ratio more favorable for adhesion, and also from the viewpoint of the anchoring effect, the thicker the coating layer is, the more advantageous for adhesion.

As an index of the boehmite treatment, besides these, it is possible to identify even the state of the color of the treated surface when platinum is deposited. Although it is possible to use the above-mentioned content as an index of the boehmite treatment, it is possible to improve the adhesiveness of the thermoplastic resin to the aluminum surface or the alumina surface by extrusion lamination.

As described above, by subjecting an aluminum foil to a hot water denaturing treatment such as a boehmite treatment, even if a thermoplastic resin is laminated on the treated surface by an extrusion lamination method, the laminating strength is sufficiently high. It is possible to obtain good adhesive strength even for resins that could not be obtained by the extrusion lamination method with the conventional extrusion lamination method, but also by selecting thermoplastic resin, it can be used as various packaging materials It is possible to obtain a laminate in which the interlaminar laminate strength does not decrease without being affected by the highly permeable content even when the highly permeable material is packaged.

As described above, even if a thermoplastic resin layer is directly provided on the boehmite-treated surface, it is possible to obtain a laminate having sufficiently good adhesion. In order to be able to be used in the contents, various isocyanate compounds are coated on the boehmite-treated surface with various coatings such as gravure to a thickness of 5 μm or less.
It is preferable that the thermoplastic resin layer is provided by 3 μm or less, more preferably 1 μm or less, and then laminated by extrusion lamination.

In general, the provision of the urethane-based adhesive layer causes a significant decrease in lamination strength due to dissociation of hydrogen bonds and swelling of the adhesive layer due to the strong osmotic contents. However, when the isocyanate-based compound is formed to be very thin alone, the laminate strength does not decrease even if the content is filled with a very strong permeable material.
As such an isocyanate-based compound, it is possible to use various monomers, derivatives, monomers, and complexes described in the item of the isocyanate-modified ethylene-based copolymer described above.

Examples of the package of the present invention include, for example, the following configuration. (A) Thermoplastic resin layer (1) (11) / adhesive layer (1)
2) / boehmite-treated aluminum foil layer (13) / (isocyanate-based compound layer) (14) / resin composition layer (1)
5) (See FIG. 1) (b) Thermoplastic resin layer (1) (11) / adhesive layer (1)
2) / boehmite-treated aluminum foil layer (13) / (isocyanate compound layer) (14) / thermoplastic resin layer (2) (11a) / resin composition layer (15) (see FIG. 2)

In the constitutions shown in (a) and (b), the resin composition layer functions as the heat-resistant sealant layer described above. The difference between (a) and (b) is that the boehmite treatment is performed. The difference is whether the heat-resistant resin composition layer is provided directly on the applied aluminum foil or laminated via the thermoplastic resin layer (2).

As the thermoplastic resin layer (1), a stretched polyester film, a stretched polyamide film, a stretched polyethylene film, a stretched polypropylene film and the like can be selected. As a method of laminating these base films and boehmite-treated aluminum foil,
Various types of adhesives such as urethane and imine can be laminated by dry lamination or non-solvent lamination using a known method such as gravure coating, reverse coating, or roll coating. If necessary, various ink layers may be provided by a known method such as the above-mentioned gravure coating in order to impart design properties to the base film.

On the other hand, to provide an isocyanate compound on an aluminum foil that has been subjected to boehmite treatment and further provide a resin composition layer or a thermoplastic resin (2), the thermoplastic resin prepared in advance by the above-described method must be used. (1)
/ Adhesive layer / Boehmite treated aluminum foil layer is set on the unwinding part of the extrusion laminating machine, and the coating unit provided in the extrusion laminating machine,
After providing an isocyanate compound having a solid content adjusted to 1 to 7 wt%, preferably 3 to 5 wt% to a dry thickness of 1 μm or less, the resin composition layer is directly provided or a thermoplastic resin (2) is provided. After that, the resin composition layer is laminated by tandem, or the resin composition layer and the thermoplastic resin (2) are laminated by co-extrusion, whereby the package having the above-mentioned constitutions (a) and (b), which has excellent content resistance, is obtained. Obtainable.

In this case, the thermoplastic resin (2) includes low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, polypropylene resin, propylene-ethylene random copolymer, and propylene-ethylene block copolymer. Polymer, propylene-α-olefin copolymer, propylene-ethylene-α-olefin copolymer, ethylene- (meth) acrylic acid copolymer,
Various types of ethylene- (meth) acrylic acid ester copolymers, ethylene- (meth) acrylic acid-ethylene- (meth) acrylic acid copolymers, and ionic cross-linked products of ethylene- (meth) acrylic acid copolymers can be selected. Although there is no limitation, in selecting this layer, a resin having good adhesion to the resin composition layer used as the sealant layer and good heat resistance is preferable.

As a method for extruding the resin composition layer, the above-mentioned resins A to D adjusted to a predetermined compounding ratio may be prepared by dry blending or various kneading apparatuses such as a twin screw extruder or a Banbury mixer. A method in which a compound is prepared in advance using the above method, and the compound is formed using a single screw extrusion laminating machine. In addition, a single film is prepared in advance using the resin composition layer or the resin composition layer and the thermoplastic resin (2) by inflation, sheet molding, extrusion knee ram molding, or the like, and then boehmite is formed by dry lamination. After providing the isocyanate-based compound on the treated aluminum, the above-mentioned single film may be bonded. If necessary, thermal lamination or the like may be performed as the secondary processing.

The heat-resistant packaging bag thus obtained is
Generally, it can be developed not only for applications requiring heat resistance, but also for applications requiring heat resistance and contents such as exterior materials such as Li batteries.

[0048]

Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Resin used] <Resin A> A-1: High-density polyethylene (density: 0.941 g / c)
^{m 3, MI = 8) A} -2: ethylene -α-olefin copolymer (density; 0.
941 g / cm ³ , MI = 4) <Resin B> B-1: High-density polyethylene-maleic anhydride graft copolymer (MI = 1.0) (graft rate 1 wt% or less) B-2: Ethylene-acryl Ethyl acrylate-maleic anhydride copolymer (MI = 10) (maleic anhydride content in main chain: 3 wt%) <Resin C> C-1: Ethylene-glycidyl methacrylate copolymer (MI = 3) ( (Resin D) D-1: ethylene-ethyl acrylate / ethylene-vinyl acetate-glycidyl methacrylate-methacryloxyethyltrimethoxysilane (MI = 23) (MI = 23) D-2: ethylene-hydroxyethyl methacrylate /
Hexamethylene diisocyanate complex (MI = 23)
(Isocyanate composite grafting rate 1 wt% or less)

[Hot-Water Denaturation Treatment of Aluminum Foil] <Treatment Method> An aluminum foil having a thickness of 40 μm was treated at pH 7
The boiling water (95 ° C.) distilled water (deionized) prepared at ~ 9 is stored in the treatment tank, so that the surface of the aluminum foil is denatured with hot water by performing in-line immersion treatment (treatment time of 3 minutes). Treatment (boehmite treatment) was performed. <Surface Analysis (1)> The spectral peak positions derived from oxides and hydroxides in Al2p orbitals were determined by X-ray photoelectron spectroscopy (XPS). When calculating the spectral peak positions derived from the oxides and hydroxides in the Al2p orbit, charging correction was performed. First, the Cls peak position was corrected to 285.0 eV, and the metal Al peak position was corrected to 72.7 eV. . The sample in which no metal Al peak was observed was corrected by the same amount as the amount shifted to 72.7 eV (about +1.6 eV) in the sample in which other metal Al peaks were observed. The measuring device was made by JEOL Ltd. JP
S-90MXVmicro, non-monochromatic MgKα (1253.6 eV) was used as the X-ray source, and the output was 10
It was measured at 0 W (10 kV-10 mA). As a result, the untreated product was 75.5 eV, and the hot water-modified product was 74.9 eV. <Surface analysis (2)> The O / Al ratio was determined by the method described above. The O / Al ratio was determined as the ratio of the value obtained by multiplying the area of each peak intensity of O1s and Al2p by the relative sensitivity of each peak. As a result, the untreated product was 1.68 and the hot-water-modified product was 2.64. <Surface Analysis (3)> The ratio of OH / O was determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS).
The OH / O ratio was determined as the intensity ratio between the OH (17) peak and the O (16) peak obtained from the negative ion mass spectrum. The measuring device is Physical elect
The measurement was performed using TRIFT II manufactured by Ronics Inc., Ga ions as an ion source, and an acceleration voltage of 15 keV. As a result, the untreated product was 0.71 and the hot water modified product was 1.02. <Surface Analysis (4)> The center surface roughness (Ra) and the root mean square surface roughness (RMs) were measured by an atomic force microscope. The measuring device was manufactured by Digital Instruments
oScope IIIa, using System D3100, AFM
The probe used was AR5-NCH having a tip curvature radius of 10 nm, a half cone angle of 5 °, and an aspect ratio of 7: 1. Measurement area is 1 × 1μm and scan rate is 0.5Hz
Was measured in the tapping mode. As a result, the untreated product was Ra = 5 nm, RMS = 7 nm, and the area ratio was 1. The hydrothermally modified product was Ra = 20 nm, RMS = 24 nm, and the area ratio was 2. <Surface analysis (5)> The thickness of the treated layer was measured by a transmission electron microscope. The measuring device is H-80 manufactured by Hitachi, Ltd.
00 was used. The acceleration voltage is 200 keV. As a result, the untreated product was 0 μm and the hot water denatured product was 0.15 μm.
m.

[Preparation of Package] A biaxially stretched polyamide film (thickness: 25 μm) and the above-mentioned hot-water-modified aluminum foil were bonded together by a dry laminating method using a two-component curing type polyurethane adhesive. These composite substrates were set on the unwinding section of a single-screw extrusion laminator. An adduct body of tolylene diisocyanate, which was previously adjusted to a solid content of 5% by weight with ethyl acetate, was set in the coating unit of the extrusion laminating machine, and was applied in a dry state to a thickness of 1 μm or less. Thereafter, resin compositions blended by dry blending as in the following Examples and Comparative Examples were laminated in-line so as to have a thickness of 30 μm. The processing speed is 50 m / min. It is. As a result, a laminate produced so as to have the structure (1) (biaxially stretched polyamide film / adhesive layer / hot-water-modified aluminum foil / isocyanate compound layer / resin composition layer) was prepared under an environment of 40 ° C. For 4 days, and thereafter, the package was formed by slitting.

Examples and comparative examples prepared by the above method will be described more specifically.

<Example 1> A package was prepared by setting the resin A-1 to 85% by weight, the resin B-1 to 7.5% by weight, and the resin C-1 to 7.5% by weight. did. In addition,
The processing temperature is 290 ° C.

<Example 2> A package was prepared by setting the resin A-1 to 85% by weight, the resin B-2 to 7.5% by weight, and the resin C-1 to 7.5% by weight. did. In addition,
The processing temperature is 290 ° C.

<Example 3> A package was prepared with 65% by weight of resin A-2 and 35% by weight of resin D-1.
Package. The working temperature is 240 ° C.

<Example 4> A package was prepared with 45% by weight of resin A-2 and 55% by weight of resin D-2.
Package. The working temperature is 240 ° C.

Example 5 A package was prepared using 90% by weight of resin A-1, 7% by weight of resin B-1, and 3% by weight of resin C-1 to obtain a package of Example 5. The processing temperature is 290 ° C.

Comparative Example 1 Extrusion was attempted at a processing temperature of 290 ° C. with resin A-1 at 50 wt%, resin B-1 at 25 wt%, and resin C-1 at 25 wt%. In addition, a remarkable increase in melt viscosity was observed, and a film could not be formed.

Comparative Example 2 99.5 wt% of resin A-1
%, Resin B-1 is 0.25 wt%, resin C-1 is 0.2
A package was prepared at 5 wt% and used as a package of Comparative Example 2. The processing temperature is 290 ° C.

<Comparative Example 3> A package was prepared using 70% by weight of resin A-1, 30% by weight of resin B-1 and 0% by weight of resin C-1 to obtain a package of Comparative Example 2. The processing temperature is 290 ° C.

<Comparative Example 4> 85% of resin A-1 was used except that an aluminum foil not subjected to the hot water modification treatment was used.
%, Resin B-1 is 7.5 wt%, and resin C-1 is 7.5 w
A package was prepared at t%, and the package of Comparative Example 2 was obtained.
The processing temperature is 290 ° C.

The heat resistance and the content resistance of nine kinds of the package bodies, which were prepared in the manner described above, including five kinds of the examples and four kinds of the comparative examples, were evaluated based on the following evaluation methods. Table 1 shows the results.

[Heat resistance evaluation method]
° C, 0.3 Mpa, 2 sec. Of the heat-sealed sample at room temperature and in an atmosphere of 100 ° C. under a condition of a sample width of 15 mm, a crosshead speed of 300 mm / min. The heat resistance was evaluated by measuring by T-type peeling.

[Method for Evaluating Content Resistance] A pouch (package) was prepared under the above sealing conditions, and as a content, an electrolyte for a Li-ion battery (a 1.5 M solution of LiPF6 in a mixed solution of ethylene carbonate and propylene carbonate) was used. ). The laminate strength of the hot water denatured aluminum foil / resin composition layer before and after storage at 40 ° C. for 4 weeks was measured using a sample width of 15 mm and a crosshead speed of 300 mm / mi.
n. Was measured by T-type peeling.

[0065]

[Table 1]

[0066]

From the results of the above Examples and Comparative Examples,
The following contents can be confirmed. In the present invention, a resin composition in which a sealant layer comprises a resin A based on a polyolefin resin and an ethylene-based copolymer (resin B and resin C) having reactivity with each other, or a resin based on a polyolefin resin A and a resin composition comprising an ethylene-based copolymer having a self-crosslinking property (resin D), and the compounding ratio of (resin B + resin C) is 1 to 30 wt% with respect to 70 to 99 wt% of resin A. Or resin A
Is 0 to 99 wt%, the resin D is 1 to 100 wt%, and the polyolefin resin A has a density of 0.925.
g / cm ³ or more of high-density polyethylene resin, medium-density polyethylene or ethylene-α-olefin copolymer, or a resin composition based on these, and (resin B / resin C) = (acid anhydride) Product-modified ethylene-based copolymer / epoxy-modified copolymer) or (ethylene-α, β-unsaturated carboxylic acid or its ion-crosslinked product / epoxy-modified copolymer), wherein resin D is a silane-modified ethylene-based copolymer Characterized by being an isocyanate-modified ethylene-based copolymer and an acid-modified ethylene-based copolymer, have a good heat-sealing property even at room temperature, and have a hot heat-sealing at 100 ° C atmosphere. It is possible to obtain a sealant layer having a heat resistance with less decrease in strength. Further, the aluminum foil to be used is subjected to a hot water denaturation treatment (particularly boehmite treatment), and further thereon,
5 μm thick isocyanate compound or its derivative
After laminating below, by simple lamination of the resin composition by extrusion lamination method, or by laminating a multilayer film containing the resin composition, for a highly permeable content such as used in Li batteries Does not cause a decrease in the laminate strength. From the above, the packaging material using polyethylene resin as the sealant layer also has the heat resistance enough to require safety like the exterior material of the Li battery, but the packaging body with excellent content resistance. These packaging bags can be developed for packaging materials requiring other heat resistance and contents.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a package of the present invention.

FIG. 2 is an explanatory sectional view showing another embodiment of the package of the present invention.

[Explanation of symbols]

 11 base film, thermoplastic resin layer (1) 12 adhesive layer 13 hot water modified aluminum foil layer 14 isocyanate compound layer 15 resin composition layer, sealant layer 11a base film , Thermoplastic resin layer (2)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 3/10 C09K 3/10 L 5H029 R H01M 2/02 H01M 2/02 K // H01M 10/40 10 / 40 Z F term (reference) 3E067 AA11 AB99 BA12A BB15A BB16A BB18A BB22A BB25A FA01 FC01 GB20 GD10 3E086 AD01 BA04 BA13 BA15 BB20 BB41 BB90 CA40 4F100 AA19B AB10B AB33B AH03C05 AK01C05 AK01C05 AK01C05 AK01C05 AK01C05 BA04 BA05 BA07 BA10A BA10C CB02 EH23 EH23C EJ05C EJ38 EJ46 EJ64B GB15 JA14C JB16A JJ03 JL12C YY00C 4H017 AA04 AB07 AB08 AC03 AC17 AD06 AE04 5H011 AA02 CC02 CC06 CC10 KK00 AM02 DJ02H00

Claims (10)

[Claims] 1. A package having a multilayer structure including a thermoplastic resin layer and an aluminum foil layer, wherein the sealant layer is a resin A based on a polyolefin resin and an ethylene copolymer (Resin B) having reactivity with each other. And a resin C). 2. An innermost sealant layer of a multilayer laminate comprising a thermoplastic resin layer and an aluminum foil layer, wherein the innermost sealant layer comprises a resin A based on a polyolefin resin and an ethylene-based copolymer having a self-crosslinking property (resin D). A package comprising a resin composition comprising: 3. The method according to claim 1, wherein the resin A is 70 to 99.
1% to 30% by weight of resin B + resin C with respect to wt%, or 1 to 10% of resin D with 0% to 99% by weight of resin A
The package according to claim 1, wherein the amount is 0 wt%. 4. The polyolefin resin A has a density of 0.925.
g / cm ³ or more of high-density polyethylene, medium-density polyethylene or ethylene-α-olefin copolymer, or a resin composition based on any of them. 4. The package according to 4. 5. The combination of the resin B and the resin C is (resin B
/ Resin C) = (acid-modified ethylene-based copolymer / epoxy-modified copolymer) or (resin B / resin C) = (ethylene-α, β-unsaturated carboxylic acid or its ion-crosslinked product / epoxy-modified copolymer) The package according to claim 1, 3 or 4, wherein 6. The resin D is any one of a silane-modified ethylene-based copolymer, an isocyanate-modified ethylene-based copolymer, and an acid-modified ethylene-based copolymer.
The package according to claim 2, 3 or 4. 7. The method according to claim 1, wherein said aluminum foil layer has been subjected to a hot water modification treatment.
The package according to 4, 5 or 6. 8. The package according to claim 1, wherein the hot water denaturing treatment is a boehmite treatment. 9. After laminating an isocyanate compound or a derivative thereof with a thickness of 5 μm or less on the hot-water-modified aluminum foil layer, the resin composition alone or containing the resin composition by extrusion lamination. The multilayer film is laminated, wherein the multilayer film is laminated.
The package according to 3, 4, 5, 6, 7 or 8. 10. The package according to claim 1, which is used as an exterior material for a lithium battery.