JP2007086364A - In mold label and packaging container for storage battery using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-mold label which obviates the occurrence of misalignment and spreading of a resin to the rear, bending and wrinkling at label ends, and degradation in yield, and more particularly can be appropriately used for a nickel hydrogen battery, and a packaging container for a storage battery using the same, and further, the packaging container for the storage battery which is excellent in water vapor barrier property, obviates the hydrolysis of the in-mold label by the influence of the moisture, etc., in the air, and is excellent in electrolyte resistance as well. <P>SOLUTION: The in-mold label is laminated in order of a thermally adhesive resin layer, an adhesive layer, a metallic foil, an adhesive layer, and a thermally adhesive resin layer, in which the thermally adhesive resin layer existing on both outer sides consists of the resin of the same kind and loop stiffness ranges from 0.10 to 0.20 N (Newton). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-mold label that does not cause misalignment, the back of a resin, or wrinkles, and does not cause a decrease in yield, and more specifically, has excellent water vapor barrier properties. The present invention relates to an in-mold label and a storage battery packaging container that prevents the influence of moisture that causes a decrease in battery performance using the same.

  In recent years, battery packs mounted on mobile products such as mobile phones, notebook computers, video cameras, etc., such as lithium ion batteries and polymer battery storage batteries made of a packaging material in which a metal foil such as plastic film or aluminum is laminated, It is used. The reason for this is that the metal terminal can be easily taken out and sealed, or can be shaped to fit the appropriate space of the electronic device or electronic component in order to have flexibility, and the electronic device or electronic component itself This is because the shape can be freely designed to some extent, and it is easy to reduce the size and weight.

  As the form of the outer package made of the packaging material, the packaging material is processed into a cylindrical shape, and the battery terminal and the metal terminal connected to each of the positive electrode and the negative electrode are stored in a protruding state, and the opening is thermally bonded. A sealed bag type (see, for example, Patent Document 1) and a packaging material are formed into a container shape, and a metal terminal connected to each of the battery element and the positive electrode and the negative electrode protrudes outside in the container. There is known a molding type (see, for example, Patent Document 2) which is housed and covered with a flat packaging material or a container-shaped packaging material and sealed by thermally bonding four peripheral edges. The packaging material used for any type is a base layer for preventing puncture resistance and external energization, a barrier layer made of metal foil such as aluminum for ensuring moisture resistance, and adhesion to metal terminals. In general, a laminate composed of an inner layer for ensuring sealing properties and sealing properties is generally used.

  And since the exterior body of the molding type described in Patent Document 2 can store battery elements and the like tightly (in a tight state) as compared with the bag type described in Patent Document 1, the volume energy Battery element [positive electrode current collector (aluminum) / positive electrode active substance layer (polymeric positive electrode material such as metal oxide, carbon black, metal sulfide, electrolyte, polyacrylonitrile)] / Electrolytes (carbonate electrolytes such as propylene carbonate, ethylene carbonate, dimethyl carbonate, ethylene methyl carbonate, inorganic solid electrolytes and gel electrolytes made of lithium salts) / Negative electrode active substance layers (lithium metals, alloys, carbon, electrolytes, poly Polymer negative electrode materials such as acrylonitrile) / Negative electrode current collector (copper) It has become the mainstream of the advantage of factors such as the storage and the like].

  However, unlike mobile products such as mobile phones, notebook computers, and video cameras, automotive batteries that require high capacity and high output do not have an exterior body that uses a packaging material. The reason for this is that automobile batteries are used in more severe environments and have a longer service life than mobile products, and further performances such as durability and safety are required.

Then, the proposal which uses a resin molding container as an exterior body of the battery for motor vehicles is made | formed (for example, refer patent document 3). The technique disclosed in Patent Document 3 is a method in which a laminate film is bonded to a plastic molded product by an in-mold molding method, that is, the laminate film is placed in a mold (cavity) and the laminate film is configured in the cavity. The same type of molten resin as the plastic film is injected to form a molded container (so-called in-mold molding). The laminate film A disclosed in Patent Document 3 (PP 30 μm / acid-modified PP resin 3 μm / aluminum) When in-mold molding is performed using foil 20 μm / acid-modified PP resin 3 μm / PP 30 μm, there is a problem that misalignment due to the injection pressure of the molten resin (deviation from the normal sticking position on the design) and the back of the resin occur. Arise. This is because Patent Document 3 describes that in-mold molding may be difficult to position the laminate film, so that it is desirable to apply heat sealing, but this is not the case with the laminate film. This is thought to be because the contact with the inner surface of the cavity becomes sweet because of the excessively strong. On the other hand, if the laminate film is weak, there is a problem that the label end is bent and wrinkles occur due to the injection pressure of the molten resin. In either case, it causes a decrease in yield and increases costs. Incidentally, the loop stiffness of the laminate film A disclosed in Patent Document 3 was 0.21 N in the layer configuration of the test sample 1 produced in the examples described later.
JP-A-9-213285 JP 2001-229888 A JP 2005-41500 A

  Therefore, the present invention has no misalignment or reverse of the resin, does not bend or wrinkle at the end of the label, and does not cause a decrease in yield. In particular, the present invention can be suitably used for a nickel metal hydride battery. It is to provide a molded label and a packaging container for a storage battery using the molded label. Furthermore, it is excellent in water vapor barrier properties, and the in-mold label is not hydrolyzed due to the influence of moisture in the air, and is resistant to electrolyte. It is providing the packaging container for storage batteries which is excellent also in.

  In order to achieve the above-mentioned object, the inventor of the present invention is an in-mold label in which a heat-adhesive resin layer, an adhesive layer, a metal foil, an adhesive layer, and a heat-adhesive resin layer are laminated in this order. The loop stiffness of the in-mold label is in the range of 0.10 to 0.20 N (Newton).

  According to a second aspect of the present invention, in the in-mold label according to the first aspect, the thermal adhesive resin layer is made of a polyolefin resin.

  The present invention according to claim 3 is the in-mold label according to claim 1, wherein the adhesive layer is formed of an acid-modified polyolefin resin.

  Moreover, the storage battery packaging container of the present invention according to claim 4 is characterized in that the in-mold label according to any one of claims 1 to 3 is attached via any one of the thermal adhesive resin layers. To do.

  The storage battery packaging container according to claim 4 is characterized in that the end surface of the in-mold label is covered with the storage battery packaging container.

  The in-mold label of the present invention has a label loop stiffness in the range of 0.10 to 0.20 N (Newton), so that the misalignment due to the injection pressure of the molten resin (deviation from the normal sticking position in design). ) And the back of the resin, or bending and wrinkling of the label can be prevented, and the yield can be improved. Moreover, the storage battery packaging container to which the in-mold label of the present invention is attached is excellent in water vapor barrier properties, the in-mold label is not hydrolyzed by the influence of moisture in the air, etc., and is excellent in electrolyte resistance. Can be.

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a diagram schematically showing a basic layer structure of an in-mold label according to the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of a storage battery packaging container in which the in-mold label according to the present invention is attached to a wall surface. In the figure, 1 is an in-mold label, 1 'is a laminated sheet, 2 is a storage battery packaging container, 3 is a resin molded product, 10 and 50 are heat-adhesive resin layers, 20 and 40 are adhesive layers, 30 Indicates a metal foil, respectively.

  FIG. 1 is a diagram schematically showing a basic layer configuration of an in-mold label according to the present invention. The in-mold label 1 includes a thermal adhesive resin layer 10, an adhesive layer 20, a metal foil 30, an adhesive layer 40, The laminated sheet 1 ′ in which the heat-adhesive resin layers 50 are laminated in order is cut into a desired dimension and / or die-cut for use.

  First, the metal foil 30 will be described. The metal foil 30 is provided to prevent water vapor from entering the inside of the storage battery from the outside, and is not particularly limited as long as the metal foil satisfies the requirements. Aluminum foil is suitable in consideration of adhesiveness and the like. Aluminum foil is manufactured by cold rolling, but its flexibility, waist strength, and hardness change under annealing (so-called annealing treatment) conditions, but the aluminum foil used in the present invention is not annealed. Aluminum foil that is softer than some hard-treated products and that has been annealed to some degree is preferred. The thickness of the aluminum foil is suitably 10 μm or more considering the pinhole of the aluminum foil alone, but if it exceeds 20 μm, the aluminum foil cannot follow the shrinkage of the injection molded resin during cooling after injection molding. In addition, warpage is likely to occur in the injection molded product. Further, the aluminum foil may be a so-called 1000 series (# 1000) pure aluminum foil having a low content of iron or the like as a different component, and the iron content may be 0.3 to 9.0% by weight. The aluminum alloy foil may be a so-called 8000 (# 8000) aluminum alloy foil, preferably contained in an amount of 0.7 to 2.0% by weight.

  Although not shown, a chemical conversion treatment layer may be provided on both surfaces of the aluminum foil 30 for the purpose of further firmly bonding the aluminum foil 30 and the adhesive layers 20 and 40 described later. The chemical conversion treatment layer is a coating-type chemical conversion treatment, particularly a phenolic resin as an aminated phenol polymer and a trivalent chromium compound because it can be continuously treated and does not require a water washing step and can reduce the treatment cost. Most preferably, the treatment is performed with a treatment solution containing a phosphorus compound.

First, an aminated phenol polymer as a phenol resin will be described. A well-known thing can be widely used as an aminated phenol polymer, for example, aminated phenol heavy which consists of a repeating unit represented by following formula (1), (2), (3), (4). Coalescence can be mentioned. X in the formula represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ₁ and R ₂ represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group, and may be the same group or different groups. In the following 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, an isobutyl group, C1-C4 linear or branched alkyl groups, such as a tert- butyl group, can be mentioned. Examples of the hydroxyalkyl group represented by X, R ₁ and R ₂ include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- C1-C4 straight or branched chain in which one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group is substituted An alkyl group can be mentioned. X in the following formulas (1) to (4) is preferably any one of a hydrogen atom, a hydroxyl group, and a hydroxyalkyl group.

Further, the aminated phenol polymer represented by the following formulas (1) and (3) is an aminated phenol containing about 80 mol% or less of repeating units, preferably about 25 to about 55 mol% of repeating units. It is a polymer. The number average molecular weight of the aminated phenol polymer is preferably about 500 to about 1 million, more preferably about 1000 to about 20,000. The aminated phenol polymer is produced by, for example, polycondensing a phenol compound or naphthol compound and formaldehyde to produce a polymer composed of repeating units represented by the following (1) to (3). It is produced by introducing a water-soluble functional group (—CH ₂ NR ₁ R ₂ ) using formaldehyde and an amine (R ₁ R ₂ NH). The aminated phenol polymer can be used singly or in combination of two or more.

  Next, the trivalent chromium compound will be described. As the trivalent chromium compound, known compounds can be widely used. For example, chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acetyl acetate, chromium chloride, sulfuric acid Potassium chromium etc. can be mentioned, Preferably they are chromium nitrate and chromium fluoride.

  Next, a phosphorus compound is demonstrated. As a phosphorus compound, a well-known thing can be used widely, For example, condensed phosphoric acids, such as phosphoric acid and polyphosphoric acid, these salts, etc. can be mentioned. Here, as said salt, alkali metal salts, such as ammonium salt, sodium salt, potassium salt, can be mentioned, for example.

The aminated phenol polymer, a trivalent chromium compound, and, as the chemical conversion layer formed using a treatment liquid containing a phosphorus compound, 1 m ² per aminated phenol polymer from about 1 to about 200mg, three It is appropriate that the chromium compound is contained in a proportion of about 0.5 to about 50 mg in terms of chromium, and the phosphorus compound is contained in a proportion of about 0.5 to about 50 mg in terms of phosphorus. More preferably, 5.0 to 150 mg, the trivalent chromium compound is contained in a ratio of about 1.0 to about 40 mg in terms of chromium, and the phosphorus compound is contained in a ratio of about 1.0 to about 40 mg in terms of phosphorus. In this case, the drying temperature is 150 to 250 ° C., preferably 170 to 250 ° C., and the heat treatment (baking treatment) is appropriate.

  Moreover, as a formation method of a chemical conversion treatment layer, the said process liquid should just be formed by selecting suitably the well-known coating methods, such as a bar-coat method, a roll coat method, a gravure coat method, and an immersion method. Further, the surface of the aluminum foil 30 forming the chemical conversion treatment layer is previously treated by a known degreasing treatment method such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method. It is preferable to keep the function of the chemical conversion treatment layer to the maximum while maintaining it for a long period of time.

  Next, the adhesive layers 20 and 40 will be described. As the adhesive layers 20 and 40, the metal foil (hereinafter referred to as an aluminum foil) 30 and a heat-adhesive resin layer 10 and 50, which will be described later, are firmly adhered, and moisture in the air or electrolyte What is not decomposed by moisture (aqueous electrolyte) is required, and the resin for forming the adhesive layers 20 and 40 is an acid-modified polyolefin resin that adheres extremely well to the aluminum foil 30, for example, graft modification with an unsaturated carboxylic acid. Suitable polyolefin-based resins and acid-modified polyolefin-based resins such as copolymers of ethylene or propylene and acrylic acid or methacrylic acid are suitable. Particularly preferred are polyolefin resins graft-modified with unsaturated carboxylic acids. As a method for forming the adhesive layers 20 and 40, the above-described resin may be laminated by heating and extruding the aluminum foil surface using a T-die extruder, and the above-described resin is formed into a film in advance. Using this, it may be laminated on the surface of the aluminum foil 30 by a thermal lamination method. The thickness of the adhesive layers 20 and 40 is 5 to 25 μm, preferably 10 to 20 μm. If the thickness is less than 5 μm, sufficient laminate strength cannot be obtained, and if it exceeds 25 μm, the effect (laminate strength) vs. cost is low. Is not desirable.

  Next, the resin that forms the thermal adhesive resin layers 10 and 50 will be described. As the resin that forms the heat-adhesive resin layers 10 and 50, a resin that strongly adheres to the adhesive layers 20 and 40 is required. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density General olefin-based resins such as ethylene resins such as polyethylene and ethylene-butene copolymers, propylene resins such as homopolypropylene, ethylene-propylene copolymers, and ethylene-propylene-butene copolymers. A linear or branched olefinic resin comprising carbon and hydrogen is suitable. The thickness of the thermal adhesive resin layers 10 and 50 is suitably 10 to 100 μm.

  As a method for forming the heat-adhesive resin layers 10 and 50, (A) the adhesive layers 20 and 40 may be laminated by heating and extrusion with a T-die extruder, or (B) the heat-adhesive properties. The above-mentioned general olefin-based resin for forming the resin layers 10 and 50 is formed into a film in advance, and the adhesive layers 20 and 40 are heated and melt-extruded by a T-die extruder and laminated by a sandwich lamination method. (C) The adhesive layer 20 and the thermoadhesive resin layer 10, and the adhesive layer 40 and the thermoadhesive resin layer 50 are coextruded on the surface of the aluminum foil 30. Alternatively, (D) a co-extruded film obtained by co-extruding the adhesive layer 20 and the heat-adhesive resin layer 10 and the adhesive layer 40 and the heat-adhesive resin layer 50 in advance with a multilayer co-extruder. Thermal lamination In which it may be laminated to the aluminum foil 30 surface by law.

  Further, since the in-mold label 1 is usually cut and / or die-cut, a flat product without curling is required. Therefore, the adhesive layer 20 and the adhesive layer provided on both surfaces of the aluminum foil 30 are required. 40, and the thermoadhesive resin layer 10 and the thermoadhesive resin layer 50 are preferably configured to have at least the same resin type and the same thickness.

  2A and 2B schematically show one embodiment of a storage battery packaging container in which an in-mold label according to the present invention is attached to a wall surface. FIG. 2A is a perspective view, and FIG. The container 2 is formed by, for example, injecting and molding a molten resin on the surface of the thermal adhesive resin layer 50 of the in-mold label 1 in a state where the in-mold label 1 is disposed in the cavity of the injection mold. The in-mold label 1 is attached so that the outer surface of the in-mold label 1 and the outer surface of the resin-molded product 3 are flush with the outer surfaces of both opposing wall surfaces (wall surface with the largest exposed area) of the resin molded product 3. It is a thing. Since the end surface of the in-mold label 1 is covered with the resin molded product 3 by sticking the in-mold label 1 to the resin molded product 3 in this way, delamination by hydrolysis from the end surface of the in-mold label 1 is performed. Since the wall surface having the largest exposed area of the resin molded product 3 is covered with the in-mold label 1 having excellent water vapor barrier properties, the resin molded product 3 is compared with a resin molded product without any in-mold label. Thus, a packaging container for a storage battery with little moisture permeation can be obtained.

  The resin used for injection molding (injection-molded resin) may be any resin that can be melted and bonded to the heat-adhesive resin layers 10 and 50. Olefin resin, polyphenylene ether, modified polyphenylene ether, or a mixture thereof. The resin used for injection molding may be transparent, translucent, opaque, or colored.

Next, the present invention will be described in more detail with reference to the following examples.
In addition, all the aluminum foils used (hereinafter referred to as AL foils) are chemically treated on both sides with chemical conversion treatment liquid consisting of three components of phenol resin, chromium fluoride (trivalent) compound and phosphoric acid in advance. A layer is formed.

[Test sample 1] -Preparation of laminate film A disclosed in Patent Document 3 An organosol made of maleic anhydride-modified polypropylene was applied to both sides of a 20 μm thick AL foil (# 8000 units) and dried at 200 ° C. to obtain a thickness. A 3 μm thick acid-modified polypropylene layer (hereinafter referred to as an acid-modified PP resin) is formed, and then an unstretched polypropylene film (hereinafter referred to as a CPP film) having a thickness of 30 μm is formed on the acid-modified PP resin surface. Lamination was performed by a thermal lamination method to prepare a laminated sheet of test sample 1 (CPP film 30 μm / acid-modified PP resin 3 μm / AL foil (# 8000) 20 μm / acid-modified PP resin 3 μm / CPP film 30 μm).

[Test sample 2]
Polypropylene resin (hereinafter referred to as PPa) graft-modified with unsaturated carboxylic acid on one side of 12 μm thick AL foil (# 8000 units) is heated and melt extruded to a thickness of 20 μm with a T-die extruder, and then 30 μm. Thick CPP film is laminated by sandwich lamination method, then PPa is heated and extruded to 20 μm thickness by T-die extruder on the other side of the AL foil, and 30 μm thick CPP film is subjected to sandwich lamination method A laminated sheet of test sample 2 (CPP 30 μm / PPa 20 μm / AL foil (# 8000) 12 μm / PPa 20 μm / CPP 30 μm) was produced.

[Test sample 3]
PPa is melt-extruded to a thickness of 20 μm with a T-die extruder on one side of a 12 μm-thick AL foil (# 1000 units), and a 30 μm-thick CPP film is laminated by a sandwich lamination method. On the other side of the AL foil, PPa is heated and melt-extruded to a thickness of 20 μm with a T-die extruder, and then polypropylene resin (hereinafter referred to as PP) is heat-melted and extruded to a thickness of 30 μm with a T-die extruder to 12 μm. After a biaxially stretched polyethylene terephthalate film (hereinafter referred to as PET film) having a thickness was laminated by a sandwich lamination method, the PET film was peeled off, and a laminate sheet of test sample 3 (PP 30 μm / PPa 20 μm / AL foil (# 1000) Table) 12 μm / PPa 20 μm / CPP film 30 μm).

[Test sample 4]
A laminated sheet of test sample 4 (PP 30 μm / PPa 20 μm / AL foil (# 8000 units) 9 μm / PPa 20 μm / CPP film 30 μm) was used in the same manner as test sample 3 except that 9 μm thick AL foil (# 8000 units) was used. Produced.

[Test sample 5]
A laminated sheet of test sample 5 (PP 30 μm / PPa 20 μm / AL foil (# 8000 units) 12 μm / PPa 20 μm / CPP film 30 μm) was used in the same manner as test sample 3 except that 12 μm thick AL foil (# 8000 units) was used. Produced.

  The loop stiffness of the test samples 1 to 5 prepared above was measured by the following test method, and the results are summarized in Table 1.

The laminated sheets of test samples 1 to 5 prepared above were stored in an autoclave (under 120 ° C. saturated steam) for 12 days, and the laminate strength between the AL foil and PPa was measured. All were 8.0 N / 15 mm width or more. It did not drop from the initial laminate strength and showed good results.

  Also, 1,000 in-mold labels were prepared by cutting the laminated sheets of test samples 1 to 5 prepared above into a rectangular shape of 60 mm × 90 mm, and the in-mold labels were placed in the cavity of the injection mold Then, by injecting and molding a molten polypropylene resin, a storage battery in which a rectangular parallelepiped in-mold label having an outer dimension of (vertical) 10 mm × (horizontal) 100 mm × (height) 70 mm and a thickness of 1 mm is attached. (The in-mold label was attached to the 100 mm × 70 mm surface of the storage battery packaging container, and the end surface of the in-mold label was covered with the injected propylene resin as shown in FIG. 2 (b). ). Test sample 1 had 5 defects such as misalignment and back of resin, and test sample 4 had 7 defects such as wrinkles and bending, but test samples 2, 3 and 5 were misaligned and There was no occurrence of defects such as the backside, wrinkles and bending. As described above, the laminated sheet having the loop stiffness in the range of 0.10 to 0.20 N in both the MD direction and the TD direction can prevent misalignment, the back of the resin, or defects such as wrinkles and bending. Yield can be improved. In addition, as for all the test samples 1-5, injection molding resin is located in CPP30micrometer surface.

It is a figure which shows the basic layer structure of the in-mold label stuck on the packaging container for storage batteries concerning this invention. It is sectional drawing which shows one Example of the packaging container for storage batteries which stuck the in-mold label concerning this invention on the wall surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-mold label 1 'Laminated sheet 2 Storage battery packaging container 3 Resin molded product 10,50 Thermal adhesive resin layer 20,40 Adhesive layer 30 Metal foil

Claims (5)

An in-mold label in which a heat-adhesive resin layer, an adhesive layer, a metal foil, an adhesive layer, and a heat-adhesive resin layer are laminated in this order, and the heat-adhesive resin layers located on both outer sides are made of the same kind of resin An in-mold label having a loop stiffness in the range of 0.10 to 0.20 N (Newton). The in-mold label according to claim 1, wherein the heat-adhesive resin layer is made of a polyolefin resin. The in-mold label according to claim 1, wherein the adhesive layer is made of an acid-modified polyolefin resin. A packaging container for a storage battery, wherein the in-mold label according to any one of claims 1 to 3 is attached via any one of the thermal adhesive resin layers. 5. The storage battery packaging container according to claim 4, wherein an end surface of the in-mold label is covered with a storage battery packaging container.

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