JP2001059187A - Surface-roughened metallic foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesion between metallic foil and the other materials and to eliminate anxiety about oxidation and corrosion caused by various chemicals by treating the surface of the metallic foil made of aluminum to roughen the surface and specifying the surface roughening degree and surface roughness. SOLUTION: The surface of aluminum metallic foil is subjected to etching, acid or alkali cleaning, anodic treatment, sealing treatment, or the like, to remove aluminum oxide on the surface of Al foil, and moreover, its surface roughness is increased. The roughening degree of the roughened surface is controlled to >=54 dyne/cm as wettability by a measuring method by a micro syringe and wetting test reagent method, and the surface roughness is controlled to >=0.2 Ra and >=1.0 Rmax by a measuring method by a tracer type surface roughness gauge. As the metallic foil, Al foil having >=15 μm thickness is preferable. On the surface of this metallic foil, an acid resistant film contg. at least one among phosphate series, chromate series, fluoride series and triazinethiol compd. series is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the adhesion between a metal foil and another material.

[0002]

2. Description of the Related Art The surface of a metal foil as a laminate material used as a packaging material is usually in a mirror surface or semi-matte state. Aluminum is the most widely used metal foil. When the aluminum foil is laminated with another material, an adhesive is applied to the surface to dry laminate the other material, or a molten resin is extruded to form a thermal adhesive layer, or the thermal adhesive layer is formed. A film is formed in advance, and while the heat-adhesive resin is melt-extruded, sandwich lamination is performed between the barrier layer and the heat-adhesive layer film.

[0003]

However, depending on the contents, some of the components permeate through the laminated material layer and reach the surface of the metal foil layer laminated as a barrier layer of the laminate. It may cause peeling between the metal surface and the bonded resin layer. That is, one of the causes of the peeling is that the adhesive strength between the metal surface and the resin layer laminated on the metal surface is weak. In addition, aluminum and the like, which are often used as metal foils, are easily oxidized and corroded by chemicals such as acids and alkalis, and these chemicals reach the metal surface from the contents side and corrode the metal surface. Also cause the peeling. Adhesion between the metal surface and the resin laminated on the surface is strong, and the surface of the metal foil does not oxidize or corrode against chemicals penetrating from the contents side to the metal foil surface. There has been a demand for a laminate product that does not peel off at the same time. When the surface of the metal foil is a mirror surface as a case that inhibits the adhesiveness, in the case of laminating the mirror surface and another material, if an impurity adheres to the metal foil surface which is the mirror surface, the adhesion portion is regarded as a planar adhesion failure portion. Sometimes it became. An object of the present invention is to provide a metal foil exhibiting stable adhesive strength in laminating a metal foil with another material and free from oxidation or corrosion by various chemicals.

[0004]

According to the present invention, at least one surface is roughened, and the surface roughness is determined as a wettability by a measuring method using a microsyringe and a wetting test reagent method of 54 dyne.
/ cm or more, surface roughness is Ra: 0.2 or more Rmax: 1.0 or more by a measuring method using a stylus type surface roughness meter, a roughened metal foil, wherein the metal foil is , Thickness 15μm
The above aluminum, on the surface of the metal foil,
An acid-resistant film containing at least one of a phosphate type, a chromate type, a fluoride type, and a triazine thiol compound type is formed. On the surface of the metal foil, a silane-based coupling substance, an organic titanium-based cup A ring material, a layer containing any one of an organic aluminum-based coupling agent is formed, and on at least one surface of the metal foil, an epoxy-based, phenol-based, melamine-based, alkyd-based, polyimide-based, unsaturated polyester-based , Polyurethane-based, unsaturated carboxylic acid-grafted polyolefin-based, polyethylene terephthalate copolymer-based, polyester-based copolymers such as polybutylene terephthalate copolymer-based, metal ion-crosslinked polyethylene, ethylene / vinyl acetate copolymer, ethylene and acrylic acid and Copolymer system with methacrylic acid, polyether The resin tank system or the like, and a protective layer made of a resin layer containing at least one more than 30% of the modified product is formed, and the metal foil,
This includes a tab for a polymer battery.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The roughened metal foil of the present invention will be described in more detail. FIG. 1 is a cross-sectional view showing various configuration examples of the roughened metal foil and other surface treatment layers of the present invention. FIG. 2 is a diagram showing a configuration example of a laminate using a roughened metal foil according to the present invention, in which (a) is a cross-sectional view and (b) is an enlarged view of a Y portion. FIGS. 3A and 3B are diagrams illustrating an example in which a roughened metal foil of the present invention is used for a tab of a polymer battery. FIG. 3A is a perspective view of a polymer battery, and FIG.
It is a perspective view of a polymer battery main body, and is an arrow view from (c) G.

[0006] As a packaging material, a package that seals a laminate formed by coating or depositing various single films, various barrier agents, or the like, or a metal foil, is generally used as a soft package. In particular, when the contents are affected by moisture and various gases and may be deteriorated or degraded, the laminated body is configured to have a free barrier property. In a laminate having a barrier property, a metal foil is often used as a barrier layer. The barrier layer is a layer for preventing a gas such as water vapor or oxygen from entering the inside of the package from the outside, and has a pinhole of a barrier layer alone, and is suitable for processing (pouching, embossability).
Stabilizing, and, in order to have pinhole resistance, a metal such as aluminum or nickel having a thickness of 15 μm or more, or an inorganic compound, for example, silicon oxide, alumina or the like. 80μm iron
It is a soft aluminum foil containing 0.3% or more. Such contents to be packaged using a laminate including a metal foil having a barrier property include cosmetics, pharmaceuticals, foods, beverages,
Adhesives, other industrial chemicals, etc., also in the form of packaging, such as laminated tubes, bags, packaging lids consisting of molded products and their lids, sheet molded type molded products, etc.
A special example is an electrode (tab) of a polymer battery.

[0007] The present inventors have proposed a method for improving the adhesiveness.
Roughening the surface of luminium has an extremely large effect
Was found. That is, FIG. 1A or FIG.
As shown in (c), oxidation existing on the aluminum surface
Aluminum (chemical formula: AL_TwoO _Three) Removal and large surface roughness
To increase the surface area and develop the anchor effect
Etching aluminum surface to improve adhesion
Cleaning with sulfuric acid, oxalic acid,
Anodizing using chromic acid and phosphoric acid and sealing
Effect of increasing roughness (irregularity) on aluminum surface
Was found. Sulfuric acid,
Inorganic acids such as hydrochloric, nitric, phosphoric, hydrofluoric and chromic acids
And sulfamic acid, oxalic acid, tartaric acid, citric acid,
Acid, lactic acid, glycolic acid, acetic acid, gluconic acid, succinic
There are courageous acids such as acid and malic acid.
What is necessary is just to add an additive suitably as a main component. Also, Arca
Lithiums include hydroxides such as sodium hydroxide and sodium carbonate.
Carbonates such as thorium and sodium bicarbonate;
Phosphates such as sodium phosphate, tribasic sodium phosphate,
Pyro sodium phosphate, tripoly sodium phosphate
Phosphates, such as sodium and tetrapoly sodium phosphate
Substances, ortho-sodium silicate, meta-sodium silicate
There are silicates. Sodium salts, but these
Potassium salts and ammonium salts are also effective. These mainly
Additives may be appropriately added as components.

[0008] Specifically, by the above-mentioned roughening,
The surface roughness of the aluminum was determined to be 54 dyne as measured by a microsyringe and a wetting test reagent method as wettability.
/ cm or more, and the surface roughness is desirably Ra: 0.2 or more and Rmax: 1.0 or more as measured by a stylus type surface roughness meter. As described above, the surface roughness is Ra: 0.2 or more, Rmax: 1.0 or more, and the wettability is set to 54 dyne / cm or more to facilitate other treatments, or other constituents of the laminate. Stabilization of the adhesive strength with the material was achieved.

Further, in order to improve the chemical resistance and organic solvent resistance of the aluminum surface, as shown in FIG. 1 (a), the aluminum foil surface is subjected to a chemical resistance treatment.
Phosphate-based film treatment, chromic acid-based film treatment, fluoride-based film treatment, or the like may be performed, or coupling treatment may be performed to improve the adhesiveness of the aluminum foil surface. The substance used in the phosphate-based coating treatment 3 is zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate, tin phosphate, silica phosphate, and the like.
The substances used for the chromic acid-based film treatment are chromium chromate, chromium phosphate, silica chromate, and the like, and the substances used for the fluoride-based film treatment are titanium fluoride and zinc fluoride.

Further, in order to stabilize the adhesiveness when the metal foil of the present invention is laminated with another material, an adhesiveness improving treatment (hereinafter, coupling treatment) is performed.
It has been found that it is effective in improving the adhesiveness. For example,
As shown in FIG. 1C, a coupling treatment layer 4 is formed on one side of the roughened metal foil, and FIG.
As shown in (1), an acid-resistant film 3 is formed on a mold surface of a metal foil whose both surfaces are roughened, and then a coupling treatment layer 4 is formed on the surface of the acid-resistant film 3. The substance used for the coupling treatment is a silane coupling agent, an organic titanium coupling agent, or an organic aluminum coupling agent. As the organic titanium-based coupling agent, tetraalkoxytitanium, titanium acylate, titanium chelate and the like can be used, and as the organic aluminum-based coupling agent, trialky aluminum, aluminum xylate, aluminum acylate and the like can be used.

On the other hand, aluminum as a packaging material is
As a material having a barrier property, it is often used by being laminated with another material, but aluminum is relatively easily corroded by an organic solvent, an acid, or an alkali among metals. As shown in FIG. 1 (f), as a component of the content, or for the purpose of preventing these substances generated by the reaction of the content with other substances from reaching the surface of the aluminum, the content side of the barrier layer is reduced. May be provided with a protective layer 5. The protective layer may be provided directly on the roughened metal foil, or as shown in FIG.
As shown in (f), it may be provided on the surface where the acid-resistant modified film is formed. Examples of the resin forming the protective layer 5 include the following. That is, copolymers such as epoxy type, phenol type, melamine type, alkyd type, polyimide type, unsaturated polyester type, polyurethane type, unsaturated carboxylic acid graft polyolefin type, polyethylene terephthalate copolymer type, polybutylene terephthalate copolymer type, etc. 30% or more of polyester, metal ion cross-linked polyethylene, ethylene / vinyl acetate copolymer, copolymer of ethylene and acrylic acid and methacrylic acid, resin such as polyether urethane, and modified products thereof. Containing resin.

In the present invention, the surface roughening process 2, the formation of the acid-resistant film 3, the coupling process 4, etc., of the metal foil surface may be performed independently, or two of these processes may be performed. The above may be performed. For example, a metal foil is roughened, an acid-resistant film is formed on the roughened surface,
Such as forming a protective layer, further improve the adhesiveness of the metal foil by performing the processing method as appropriate, and,
Oxidation and corrosion of the metal foil surface by various substances can be prevented. In addition, the acid-resistant film and the main components used for the coupling treatment, including the protective layer, can be mutually added to the respective coating liquids and treatment liquids to obtain a synergistic effect on the object of the present invention. .

When the roughened metal foil of the present invention is used for a laminate, for example, as shown in FIG.
In the case of a four-layer type such as 1, a barrier layer 12, an intermediate layer, and a thermal bonding layer 14, the metal foil of the present invention can be used as the barrier layer 12. In the example shown in FIG. 2B, the acid-resistant film 3 is formed on one surface of the degreased metal foil 1, and the coupling treatment layer 4 is further provided. In the laminate, in the adhesion between the base material layer 11 and the barrier layer 12, and in the adhesion between the barrier layer 12 and the intermediate layer 13,
Roughened surface 2 of metal foil 1 of the present invention and base material layer 11
Alternatively, the adhesion with the intermediate layer 13 becomes stable.

The outermost layer 11 is generally used as a substrate film of the outermost layer for producing the laminate 10 and is preferably made of a material having high tensile strength, good dimensional stability, printability, heat resistance and the like. Specifically, biaxially stretched polypropylene, polyester, nylon and the like can be suitably used.

The intermediate layer 13 is provided to further improve the physical properties of the packaging bag, and includes, for example, protection of the barrier layer (to prevent the performance of the barrier layer from deteriorating), and strength of the packaging body. It is laminated for the purpose of improving and providing rigidity. The intermediate layer 13 may be formed of a single resin, or may be a laminate of two or more layers.

The innermost layer 14 may be a general heat-adhesive resin, but is a layer made of a resin capable of meeting conditions such as heat resistance, cold resistance and physical properties with respect to contents. As a special use, when used for an outer package of a polymer battery, a resin having thermal adhesion to a metal may be used. Examples of the resin having thermal adhesion to metals include unsaturated carboxylic acid-grafted polyethylene, unsaturated carboxylic acid-grafted polypropylene, unsaturated carboxylic acid-grafted polyolefin such as unsaturated carboxylic acid-grafted polymethylpentene, metal ion-crosslinked polyethylene, ethylene or propylene. And acrylic acid derivatives or methacrylic acid derivatives, and resins containing at least one of these modified products.

The roughened metal foil of the present invention is also applicable to a tab of a polymer battery. Polymer battery PB
As shown in FIGS. 3A and 3C, the polymer battery main body BH is housed in an outer package C, and a peripheral portion of the outer package C is heat-sealed to form a heat-sealed portion HS. When sealing is performed, a part of the electrode (tab) T is held
Is thermally bonded to the innermost layer resin. In the thermal bonding, if the metal tab T is a mirror surface, the thermal bonding may not be completed. Therefore, it was found that the use of the roughened metal foil of the present invention makes the thermal bonding perfect.

The tab T of the polymer battery is made of a thin piece of metal such as aluminum or nickel. As described above, when the polymer battery main body BH is housed in the outer casing C and sealed, a part of the outer casing is used. C, and is heat-bonded to the innermost resin of the outer package C during heat sealing of the edge of the outer package C, and hermetically sealed as a polymer battery. For this reason, as the innermost layer resin of the exterior body C, a resin having thermal adhesiveness to metal is selected. Examples of the heat-adhesive resin include, for example, unsaturated carboxylic acid-grafted polypropylene, unsaturated carboxylic acid-grafted polyethylene, unsaturated carboxylic acid-grafted polyolefin resin such as unsaturated carboxylic acid-grafted polymethylpentene, metal ion crosslinked polyethylene, ethylene or propylene. A resin containing at least one of a copolymer of acrylonitrile and an acrylic acid derivative or a methacrylic acid derivative and a modified product thereof is used. However, if the tab surface of the polymer battery is a mirror surface, the adhesion to the innermost resin of the outer package may be unstable.

Therefore, by using the roughened metal foil of the present invention as a tab, the adhesion between the innermost layer resin of the outer package and the tab is extremely stable. For the tab T of the polymer battery PB, the surface roughening treatment of the present invention may be applied to the entire area of the tab T. However, the coupling treatment, the formation of the acid-resistant film, the formation of the protective layer, etc. Since the conductivity of the surface is impaired or may be impaired, it is not processed except for the region sandwiched by the outer casing C, and is partially applied to the bonding portion between the innermost layer of the outer casing C of the polymer battery and the tab T. Process.

[0020]

【Example】

EXAMPLE Next, a sample was prepared by using the metal foil having a roughened surface of the present invention and specifically filled with contents such as a laminate, and the effect was confirmed. In the following description, all the adhesives used for dry lamination are of a polyester type. The surface roughness of aluminum in each example is as shown in Table 1.

[Table 1] Example 1 One side of aluminum 20 μm was subjected to a phosphate treatment to form an acid-resistant film, and then an ethylene / vinyl acetate copolymer was extruded to a thickness of 10 μm and laminated to form a lid. A 300 ml glass bottle was filled with vermond vinegar and heat bonded with the lid. Example 2 One side of aluminum 15 μm was subjected to a phosphate treatment to form an acid-resistant film, and then a protective layer made of an epoxy resin was formed on the surface on which the acid-resistant film was formed to a thickness of 2 μm. On the surface of the protective layer, 5 μm of unsaturated carboxylic acid-grafted polypropylene was formed by a coating and baking method to obtain a lid. A 500 ml glass bottle was filled with wine and heat-bonded with the lid. Example 3 Biaxially stretched polyester film 12 μm and 2 μm
An axially stretched nylon film of 15 μm and aluminum of 9 μm are sequentially bonded by dry lamination, and the bonded aluminum surface is chromate-treated to form an acid-resistant film. Then, a cast polypropylene film of 30 μm and dry lamination are used. And bonded together. The cast polypropylene was used as a heat-adhesive resin layer to form a pouch, and an analgesic poultice (a poultice) was hermetically packaged. Example 4 100 μm of aluminum having an acid-resistant film formed by phosphate treatment on one side was used, and 25 μm
An axially stretched nylon film was dry-laminated, and a 30 μm cast polypropylene film was adhered to another surface by a dry lamination method to produce a laminate. It was molded into a round cup shape having a depth of 10 mm and a diameter of 50 mm, and the lid material was sealed with a fragrance using a laminate having the same specifications. Example 5 An air-sealed fragrance was produced under the same conditions as in Example 4 except that aluminum having both surfaces treated with phosphate to form an acid resistant film of 100 μm was used. Example 6 An aroma was formed under the same conditions as in Example 4 except that one side of aluminum was treated with chromate to form an acid-resistant film, and a protective layer of epoxy resin was formed on the surface of the acid-resistant film to a thickness of 2 μm. A sealed product was prepared. [Example 7] Aroma treatment was performed under the same conditions as in Example 4 except that one side of aluminum was treated with chromate to form an acid-resistant film, and a protective layer of phenolic resin was formed on the surface of the acid-resistant film to a thickness of 3 µm. A sealed product was prepared. Example 8 The same conditions as in Example 4 were used except that one side of aluminum was subjected to chromate treatment to form an acid-resistant film, and the film surface was subjected to a silane coupling treatment with a thickness of 1 μm. A sealed fragrance was prepared. Example 9 Low-density polyethylene 15 μm, biaxially stretched polyester film 12 μm, and aluminum 15 μm were sequentially laminated by a dry lamination method, an acid-resistant film was formed on the aluminum surface with chromate, and a phenol-based film was formed on the film surface. Is formed to a thickness of 3 μm,
A laminate was formed by laminating 15 μm of low-density polyethylene on the surface of the protective layer by a dry lamination method, a laminate tube having the laminate as a body was molded, and an organic solvent-containing adhesive was filled and sealed. The shoulder portion of the laminate tube was filled with aluminum rondelle, and the spout port was sealed with a plastic cap after an aluminum inner seal. The evaluation described below confirmed peeling at the main body. Example 10 An acid-resistant film was formed by chromate on both surfaces of aluminum, a protective layer of phenol resin was provided on one surface of the acid-resistant film, and a protective layer of epoxy resin was formed on the other surface. On the surface of the protective layer of the phenol resin, an ethylene methacrylic acid copolymer
0 g / m ² was bonded by a sandwich lamination method, and low-density polyethylene was further laminated on the paper to a thickness of 15 μm. Further, a biaxially stretched polyester film 12 μm and a low-density polyethylene 30 μm are sequentially laminated to the protective layer surface of the epoxy resin by a dry lamination method. The container was molded, filled with a surfactant-based liquid detergent and sealed. [Comparative Examples 1 to 10] In the formation of the laminate in the above example, the same content as in each corresponding example was used, except that unroughened aluminum was used, and that no surface treatment layer was provided. Storage conditions were used. <Evaluation method> Adhesion stability: After filling the contents, the presence or absence of delamination (delamination) between aluminum and the adherend on the contents side after one month after storage at a temperature of 40 ° C and a humidity of 90% RH was examined. During storage, at least the contents were kept in a state of directly contacting the inner surface of the laminate. The delamination was a delamination having a peel strength between the aluminum and the adherend of 50 g / 15 mm width or less in T-peeling. <Evaluation Results> No delamination was observed in any of Examples 1 to 10. In each of Comparative Examples 1 to 10, delamination was observed.

[0021]

By roughening the metal foil, the adhesion between the metal foil and another material is improved. In addition, the laminated body using the roughened metal foil of the present invention can also be used to peel off the metal foil surface due to oxidative corrosion due to the components of the content or a substance generated by a reaction between the content and another substance. As a result, it was possible to obtain a laminated body having stable adhesiveness, that is, having no fear of peeling or the like even during long-term use. Also,
When the tab of the polymer battery is sandwiched between the outer package and thermally bonded, the use of the roughened metal foil of the present invention ensures the thermal bonding with the outer package.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing various configuration examples of a roughened metal foil and other surface treatment layers of the present invention.

FIGS. 2A and 2B are diagrams showing a configuration example of a laminate using a roughened metal foil of the present invention, wherein FIG. 2A is a cross-sectional view, and FIG. It is sectional drawing which shows the Example of the laminated body containing a metal foil.

FIGS. 3A and 3B are diagrams illustrating an example in which a roughened metal foil of the present invention is used for a tab of a polymer battery; FIG. 3A is a perspective view of a polymer battery; FIG.
(C) It is an arrow view from G.

[Explanation of symbols]

 K Metal foil provided with surface treatment layer 1 Metal foil 2 Roughened layer 3 Acid-resistant film forming layer 4 Coupling treatment layer 5 Protective layer 10 Laminate 11 Base layer 12 Barrier layer 13 Intermediate layer 14 Thermal adhesive resin Layer 15 Adhesive layer PB Polymer battery BH Polymer battery main body C Outer body HS Heat seal part T Tab S Surface treatment layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C23C 22/24 C23C 22/24 22/34 22/34 H01M 2/26 H01M 2/26 A 2/30 2 / 30 B 2/34 2/34 B (72) Inventor Yuichi Hirai 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Inventor Yoichi Mochizuki Ichigaya-Kagamachi, Shinjuku-ku, Tokyo 1-1-1 Dai Nippon Printing Co., Ltd. (72) Rikiya Yamashita 1-1-1, Ichigaya Kagacho, Shinjuku-ku, Tokyo F-term (reference) 4F100 AA04B AA05B AB01A AB10A AB33A AH03B AH04B AH07B AK03C AK04C AK33C AK36C AK41C AK41G AK42C AK44C AK49C AK51C AK52B AK53C AK68C AK70C AL01C AL07C AR00B BA02 BA03 BA06 BA10C CA05B CB03 J04A14J04B14 J04A01 BA05 BA06 BA07 BB08 CA23 CA28 EA07 EA12 EA14 4K044 AA06 BA15 BA17 BA20 BA21 BB02 BC02 CA04 CA16 CA53 5H022 AA09 CC19 EE05 EE06 KK03

Claims (6)

[Claims] The surface roughness of at least one surface is determined to be at least 54 dyne / cm as a wettability by a measuring method using a microsyringe and a wetting test reagent, and the surface roughness is a stylus type surface roughness. A roughened metal foil characterized by having a Ra: 0.2 or more and a Rmax: 1.0 or more as measured by a meter. 2. The roughened metal foil according to claim 1, wherein the metal foil is aluminum having a thickness of 15 μm or more. 3. An acid-resistant film containing at least one of a phosphate, a chromate, a fluoride, and a triazinethiol compound is formed on the surface of the metal foil. The roughened metal foil according to claim 1 or 2. 4. A layer comprising any one of a silane coupling substance, an organic titanium coupling substance, and an organic aluminum coupling treatment substance is formed on the surface of the metal foil. A roughened metal foil according to any one of claims 1 to 3. 5. An epoxy-based, phenol-based, melamine-based, alkyd-based, polyimide-based, unsaturated polyester-based, polyurethane-based, unsaturated carboxylic acid-grafted polyolefin-based, polyethylene terephthalate copolymer-based system on at least one surface of the metal foil. Copolymer polyesters such as polybutylene terephthalate copolymers, metal ion crosslinked polyethylene, ethylene / vinyl acetate copolymers, copolymers of ethylene with acrylic acid and methacrylic acid, resins such as polyether urethanes, and the like The roughened metal foil according to any one of claims 1 to 4, further comprising a protective layer formed of a resin layer containing at least one of the modified products of (i) at least 30%. 6. The roughened metal foil according to claim 1, wherein the metal foil is a tab of a polymer battery.