JP2012052158A - Aluminum foil and container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum foil which does not need additional metals other than iron, has versatility and is excellent in formability, and to provide a container formed using the aluminum foil.SOLUTION: The aluminum foil includes iron of 0.7-1.7 mass%, has a thickness of 10-150 μm, and the ratio of the diffraction intensity at (100) plane to the total diffraction intensity which is the sum of the intensities at (111), (100), (110) and (311) planes is 30-50%, and the ratio of the diffraction intensity at (110) plane to the above total diffraction intensity is 15-40%.

Description

  The present invention relates generally to an aluminum foil and a container, and more particularly to a forming aluminum foil and a container molded using the same. In the present specification, the term “aluminum foil” is used to include not only pure aluminum foil but also aluminum alloy foil.

  Conventionally, 5000 series and 6000 series aluminum alloys defined in JIS H 4000-2006 have been developed as aluminum materials excellent in moldability such as deep drawability. However, these aluminum alloys require various additive elements in order to produce them, have a high production cost, are selectively used depending on the application, and lack versatility. Moreover, since said aluminum alloy has low ductility, it is not suitable for the rolling process to a thin foil. Therefore, from the viewpoint of manufacturing cost, versatility, and ductility, it is expected to use 1000 series pure aluminum and 8000 series aluminum alloy, but aluminum foil having a thickness of 10 μm or more excellent in forming processability is industrially used. Has not been developed yet.

  For example, Japanese Laid-Open Patent Publication No. 9-272938 (hereinafter referred to as Patent Document 1) proposes an aluminum foil having high strength and good stretchability, and a method for producing the same.

  Japanese Patent No. 2754263 (hereinafter referred to as Patent Document 2) proposes an aluminum foil having excellent strength and moldability and having few pinholes, and a method for producing the same.

JP-A-9-272938 Japanese Patent No. 2754263

  However, the aluminum foil described in Patent Document 1 contains Fe: 0.10 to 0.8 wt%, Ti: 0.001 to 0.02 wt%, and the balance is inevitable impurities and Al. Medium Si is less than 0.15 wt%, not only its composition is limited, but also its manufacturing method is limited to continuous cast rolled material, so it is not versatile and not suitable for industrial production .

  Further, the aluminum foil described in Patent Document 2 also has Fe: 0.8 to 2.0% by weight, Si: 0.15% by weight or less, an Fe / Si ratio of 15 or more, and unavoidable impurities of 0.05 respectively. Not only the composition is limited to not more than% by weight, but in the production method, when the homogenization heat treatment is performed, the heating temperature T (° C.) is in the range of 400 ° C. hr) must satisfy the formula t ≦ (55−0.1T) (where t ≦ 10), so that process control is difficult. Further, in the manufacturing method, since the homogenization heat treatment temperature is low, a sufficiently homogenized slab cannot be obtained. Therefore, the quality variation of the rolled aluminum foil is large, which is described in Patent Document 2. Aluminum foil is also not suitable for industrial production.

  In any case, an aluminum foil having a thickness of 10 μm or more, which is versatile and has excellent moldability, has not yet been developed industrially.

  Accordingly, an object of the present invention is to provide an aluminum foil that does not require any additional element other than iron, has versatility, and is excellent in molding processability, and a container molded using the aluminum foil. .

  As a result of intensive studies to solve the above problems, the present inventors have found that an aluminum foil having specific physical properties is excellent in molding processability without requiring an additive element. That is, the aluminum foil of this invention and the container shape | molded using it have the following characteristics.

  The aluminum foil according to the present invention contains 0.7% by mass or more and 1.7% by mass or less of iron and has a thickness of 10 μm or more and 150 μm or less. In X-ray diffraction, (111) plane, (100) plane, ( The ratio of the diffraction intensity showing the (100) plane to the total diffraction intensity, which is the sum of each diffraction intensity showing each of the 110) plane and the (311) plane, is 30% or more and 50% or less, and the above total diffraction intensity The ratio of the diffraction intensity indicating the (110) plane with respect to is 15% or more and 40% or less.

  A container according to one aspect of the present invention is manufactured by molding an aluminum foil having the above characteristics.

  A container according to another aspect of the present invention is manufactured by molding a laminate material including the aluminum foil having the above characteristics and a resin film.

  Furthermore, a container according to another aspect of the present invention is manufactured by molding a laminate material including the aluminum foil having the above characteristics, a resin film, and a heat bonding layer.

  Since the aluminum foil of the present invention having the above characteristics exhibits a high Erichsen value, it has good formability. Therefore, according to the present invention, an aluminum foil having versatility and excellent moldability can be obtained without particularly requiring an additive element other than iron.

  Further, by molding the aluminum foil of the present invention, a container having a large molding depth or a container in which defects such as molding cracks hardly occur can be obtained.

  Furthermore, by molding a laminate material containing the aluminum foil and resin film of the present invention, it is possible to obtain a laminate material container having a large molding depth or a laminate material container in which defects such as molding cracks are unlikely to occur. it can.

  Embodiments of the present invention will be described below.

  The aluminum foil of the present invention contains 0.7% by mass or more and 1.7% by mass or less of iron (Fe). The Fe content is preferably 0.95% by mass to 1.7% by mass, and more preferably 1.1% by mass to 1.7% by mass. In order to refine the aluminum crystal grains, suppress the generation of coarse intermetallic compounds, and ensure appropriate strength and elongation, the Fe content ranges from 0.7% by mass to 1.7% by mass. It is suitable to be within. However, if the Fe content is less than 0.7% by mass, the effect of refining aluminum crystal grains is insufficient, the strength of the foil is not sufficient, and relatively many pinholes tend to occur after cold rolling. is there. On the other hand, if the Fe content exceeds 1.7% by mass, coarse intermetallic compounds are likely to be generated, workability (rollability, formability) is inferior, and pinholes are also likely to occur.

  In the aluminum foil of the present invention, the content of silicon (Si) is preferably 0.30% by mass or less, more preferably 0.15% by mass or less. When the Si content exceeds 0.30% by mass, coarse crystals are likely to be generated, and the effect of refining aluminum crystal grains is reduced, and the strength and workability tend to be reduced. Since Si inevitably exists in industrial aluminum, the lower limit value of the Si content may be 0.01% by mass.

  In the aluminum foil of the present invention, the content of copper (Cu) is preferably 0.05% by mass or less, more preferably 0.02% by mass or less. If the Cu content exceeds 0.05 mass%, workability and corrosion resistance may be reduced. In addition, since Cu inevitably exists in industrial aluminum, the lower limit value of the Cu content may be 0.001% by mass.

  In the aluminum foil of the present invention, the balance other than the above elements is aluminum (Al). However, the aluminum foil of the present invention may contain 0.05% by mass or less of trace elements other than the above-described Fe, Si, and Cu. Examples of the trace element include manganese (Mn), magnesium (Mg), zinc (Zn), titanium (Ti), zirconium (Zr), gallium (Ga), chromium (Cr), vanadium (V), and the like. These elements may exist in trace amounts in the aluminum as inevitable impurity elements.

  Although the composition of the aluminum foil of the present invention has been described above, the composition of the aluminum foil of the present invention corresponds to, for example, alloy numbers 8021 and 8079 defined in JIS H 4160-1994, which are commercially available. The composition is preferably Therefore, the aluminum foil of the present invention does not require an expensive additive element, is a versatile aluminum foil having a composition close to 8000 series or 8000 series, and is excellent in moldability.

  The thickness of the aluminum foil of the present invention is 10 μm or more and 150 μm or less, preferably 20 μm or more and 80 μm or less. If the thickness of the aluminum foil is less than 10 μm, the aluminum foil may be broken during molding or a pinhole may be generated (or enlarged). When the thickness of the aluminum foil exceeds 150 μm, not only is it difficult to obtain an X-ray diffraction intensity ratio in the range specified in the present invention, but the weight increases when the container is molded, and the molding pressure increases. .

  In the X-ray diffraction of the aluminum foil of the present invention, (100) with respect to the total diffraction intensity, which is the sum of each diffraction intensity showing each of the (111) plane, (100) plane, (110) plane, and (311) plane The ratio of the diffraction intensity showing the surface is 30% or more and 50% or less. The ratio of the diffraction intensity indicating the (110) plane to the total diffraction intensity is 15% or more and 40% or less. By limiting the ratio of the diffraction intensity indicating the (100) plane and the ratio of the diffraction intensity indicating the (110) plane within the above range, excellent moldability can be obtained.

The ratio (P ₁₀₀ ) of the diffraction intensity indicating the (100) plane in X-ray diffraction is the (111) plane, (100) plane, (110) plane, and (311) on the diffraction chart in the X-ray diffractometer. Each diffraction intensity indicating each of the surfaces is measured as an integrated intensity after removing the background (BG), and is calculated by the following formula 1 as a ratio to the total diffraction intensity, which is the sum of the diffraction intensity. The actual integral intensity is measured by reading using an integral intensity calculation program that is analysis software of the X-ray diffractometer used. Further, the background removal of the X-ray diffraction intensity is performed using the manual method in the above-described integrated intensity calculation program.

P ₁₀₀ = [[Diffraction intensity of (100) plane] / [Total of each diffraction intensity of (111) plane, (100) plane, (110) plane, and (311) plane]) × 100 [%] · ..Formula 1

The ratio (P ₁₁₀ ) of diffraction intensity indicating the (110) plane in X-ray diffraction can be obtained in the same manner. That is, the numerator in the above formula may be replaced with “(110) plane diffraction intensity”. In addition, the surface which measures X-ray diffraction intensity is a rolling surface of aluminum foil, ie, a surface which contacts a rolling roll at the time of cold rolling at the time of manufacturing aluminum foil.

  The moldability of the aluminum foil of the present invention is measured by the Eriksen test (JIS Z 2247) of the aluminum foil and evaluated by the Eriksen value (depth). By improving this Erichsen value, the moldability of the aluminum foil can be improved.

  In order to improve the Erichsen value of aluminum foil, it is generally considered to improve the tensile elongation in a tensile test. As a general means for improving the tensile elongation, it is possible to refine aluminum crystal grains. It is done. However, the average crystal grain size of aluminum in the aluminum foil of the present invention is about 5 to 10 μm, and it is technically difficult to further refine crystal grains. For this reason, it is difficult to further improve the tensile elongation. Therefore, as a result of intensive studies, the present inventors have found that, in an aluminum foil having a thickness of 10 to 150 μm, an improvement in the Erichsen value of the aluminum foil is related to a predetermined crystal orientation rather than tensile elongation. It was. That is, in the diffraction intensity detected by X-ray diffraction, the ratio of the diffraction intensity indicating the (100) plane is 30% or more and 50% or less with respect to the total diffraction intensity, and the diffraction intensity indicating (110). It has been found that the Erichsen value of the aluminum foil is excellent when the ratio is within the range of 15% to 40%. If each ratio of the diffraction intensities indicating the (100) plane and the (110) plane is out of the above range, the balance of the crystal orientations is deteriorated, resulting in a decrease in the Erichsen value.

  And in order to make each ratio of the diffraction intensity which shows a (100) plane and a (110) plane fall in a predetermined range, although it does not restrict | limit, the ingot of said aluminum foil composition is homogenized heat processing. When performing the homogenization heat treatment, the homogenization heat treatment may be performed at a temperature (for example, 570 ° C. to 630 ° C.) higher than a conventionally performed temperature (about 500 to 540 ° C.). The working conditions of the plate making process (hot rolling, cold rolling, intermediate annealing) and the working conditions of the foil making process (cold rolling) may be set to general conditions. The aluminum foil having a high Erichsen value can be stably produced by subjecting the aluminum foil having a thickness of 10 to 150 μm thus obtained to final annealing.

  In addition, by using the aluminum foil of this invention, the moldability in the laminate material containing an aluminum foil and a resin film can also be improved.

  As described above, the method for producing the aluminum foil of the present invention is not particularly limited, but it is preferable to use an industrially implemented rolling method. For example, a slab having a predetermined component obtained by a semi-continuous casting method is subjected to a homogenization heat treatment (also referred to as soaking), followed by steps of hot rolling, intermediate annealing, cold rolling, and final annealing. An aluminum foil can be obtained. Here, the homogenization heat treatment is preferably performed at 570 ° C. or higher, and more preferably at 600 ° C. or higher. By doing in this way, it becomes easy to obtain the aluminum foil which has the appropriate X-ray diffraction intensity ratio prescribed | regulated by this invention. The homogenization heat treatment time may be appropriately determined according to the size of the slab and the performance of the heat treatment furnace, but it is usually 1 hour to 20 hours, preferably about 2 to 10 hours. Following the homogenization heat treatment, hot rolling may be performed at a temperature of 400 ° C. to 500 ° C., and after cooling to near room temperature, cold rolling may be performed until a predetermined thickness is reached. You may implement intermediate annealing (300-400 degreeC) in the middle of cold rolling as needed. After the cold rolling is completed, final annealing is performed at about 250 to 450 ° C. Each heat treatment time may be appropriately determined depending on the capacity of the furnace and the amount and size of the product (or sample), but is usually several hours to several tens of hours. In addition, although a hot rolling process is required at the time of industrial mass production, a hot rolling process is not necessarily required in laboratory-based experiments and trial manufacture.

  The aluminum foil of the present invention can be formed by a press machine or the like (preferably cold forming) to produce a container, but a resin film and / or a heat bonding layer (such as a sealant film) is appropriately laminated. Thereafter, the container can be manufactured by cold forming.

  As the resin film, a resin film having a thickness of 5 μm to 500 μm is preferable. The material of the resin film is, for example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid. Ethyl copolymer, ethylene-acrylic acid or methacrylic acid copolymer, methylpentene polymer, polybutene resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, vinyl chloride-vinylidene chloride copolymer , Poly (meth) acrylic resin, polyacrylonitrile resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyester resin, polyamide Tree , Polycarbonate resin, polyvinyl alcohol resin, saponified ethylene-vinyl acetate copolymer, fluorine resin, diene resin, polyacetal resin, polyurethane resin, nitrocellulose, cellophane, etc. Can do. The resin film may be stretched in a uniaxial direction or a biaxial direction. If necessary, the surface of the resin film can be coated with an anchor coating agent or the like to be subjected to a surface smoothing treatment or the like. By laminating the resin film, corrosion resistance, insulation, safety, strength, puncture resistance, abrasion resistance, and the like can be improved.

  Examples of the heat bonding layer include low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, and ethylene-acrylic acid copolymer. Polyolefin resins such as polymers, ethylene-ethyl acrylate copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, methylpentene polymers, polybutene polymers, polyethylene or polypropylene Modified with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc., acid-modified polyolefin resin, polyvinyl acetate resin, poly (meth) acrylic resin, polychlorinated Made mainly of vinyl resin Heat adhesive or heat-adhesive film to be able to make stacked. By laminating the thermal adhesive layer, sealing properties, stability over time, and the like can be imparted to the aluminum foil.

  The method for laminating the resin film and / or the thermal adhesive layer is not particularly limited, and a known method such as dry lamination method, extrusion lamination method, wet lamination method, heat lamination method, roll coating, and gravure printing is adopted. can do.

  With the aluminum foil of the present invention as it is or with the resin film and / or the thermal adhesive layer laminated (laminated) on the aluminum foil of the present invention, a molding process (preferably cold molding) is performed. A container (preferably a container with a flange) can be produced by processing or cold plastic working. The manufactured container can be suitably used as a container for foods, beverages, contact lenses, chemicals, electronic parts, chemicals, drugs, etc., a battery outer container, and the like.

  As will be described below, samples of aluminum foils of Examples and Comparative Examples of the present invention were prepared.

  Using the alloys A to F shown in Table 1, samples of the aluminum foils of Examples 1 to 12 and Comparative Examples 1 to 6 shown in Table 3 were prepared according to the manufacturing steps A to J shown in Table 2. In Table 1, “other element meter” indicates the total content of inevitable impurity elements (B, Bi, Pb, Na, etc.) other than the elements specified by JIS.

  As shown in Table 2, in the manufacturing steps A to F, an ingot of aluminum alloy obtained by DC casting was subjected to homogenization heat treatment at a predetermined temperature and time in a heating furnace. Then, without performing hot rolling, cold rolling was performed a plurality of times, intermediate annealing was performed at a predetermined temperature and time during the cold rolling, and cold rolling was performed until the thickness reached 50 μm. Furthermore, by performing final annealing at a predetermined temperature and time, a sample of an aluminum foil having a thickness of 50 μm was produced as shown in Table 3. In addition, in manufacturing process AF, process 1, 3-6 other than the manufacturing process of an ingot was performed with research equipment.

  Moreover, as shown in Table 2, in the manufacturing processes GJ, the ingot of the aluminum alloy obtained by DC casting was subjected to homogenization heat treatment at a predetermined temperature and time in a heating furnace. Thereafter, hot rolling was performed at a starting temperature of 480 ° C. until the thickness became about 6.5 mm. Using the obtained hot rolled material, cold rolling is performed a plurality of times, intermediate annealing is performed at a predetermined temperature and time during the cold rolling, and cold rolling is performed until the thickness reaches a predetermined value. It was. Furthermore, by performing final annealing at a predetermined temperature and time, samples of aluminum foil having thicknesses shown in Table 3 were produced. In addition, in manufacturing process GJ, not only the ingot manufacturing process but all the processes 1-6 were performed with the mass production machine. Further, in the manufacturing processes G to J, since the homogenization heat treatment temperature is high, if the ingot temperature reaches the homogenization heat treatment temperature, then the ingot is cooled to a temperature at which hot rolling can be started. Also good. Furthermore, the homogenization heat treatment time is not limited to the time shown in Table 2 as long as it is within a general processing time. Since the intermediate annealing conditions do not significantly affect the characteristics of the present invention, the intermediate annealing conditions are not limited to the temperatures and times shown in Table 2, and may be within the range of general operating conditions.

  For each sample of the obtained aluminum foil, the X-ray diffraction intensity was measured in order to calculate the ratio of the diffraction intensity indicating the (100) plane and the ratio of the diffraction intensity indicating the (110) plane. In addition, the Erichsen value was measured in order to evaluate the moldability of each sample of the aluminum foil. The tensile strength, proof stress and elongation were also measured for each sample of aluminum foil.

  The X-ray diffraction intensity is measured by using an X-ray diffractometer manufactured by Rigaku Corporation (type: RINT-2000) under the conditions of CuKα ray, 40 kV, 40 mA, and (111) The measurement was performed by measuring the X-ray diffraction intensity (integrated intensity after background removal) of the plane, (100) plane, (110) plane, and (311) plane. Using the value of the X-ray diffraction intensity of each surface thus obtained, the relative diffraction intensity ratio was calculated according to the above formula 1.

  The Eriksen test was conducted according to JIS Z 2247-2006 using an electric Erichsen coating film testing machine (516-M) manufactured by Yasuda Seiki Seisakusho. The Eriksen value measured by the Eriksen test was rounded to the first decimal place in accordance with JIS Z 8401-1999. However, spray type high grease (manufactured by Taiho Kozai Co., Ltd.) was used as the grease to be applied to the aluminum foil sample during the test, and the grease was applied only to the surface (one side) of the aluminum foil with which the test punch contacted.

  The tensile strength, proof stress and elongation were measured using a tensile tester (Stragraph VE50D manufactured by Toyo Seiki Co., Ltd., strain rate: 20 mm / min, sample width: 15 mm, distance between chucks: 100 mm).

  The above measurement results are shown in Table 3. The underlined values in Table 3 indicate that the diffraction intensity ratio is outside the scope of the present invention. Moreover, about the sample (Examples 1-8 and Comparative Examples 1-4) produced using the alloy A and the alloy B, the elixir of the sample produced using the ingot homogenized and heat-treated at the lowest temperature. Based on the value, the rate of increase / decrease in Eriksen value is shown for reference.

  From the results shown in Table 3, it can be seen that the aluminum foils of the examples show high Erichsen values by limiting the diffraction intensity ratio within the range of the present invention. Moreover, in Examples 9-12, it turns out that the aluminum foil of various thickness within the range of 15-150 micrometers shows a high Erichsen value by limiting a diffraction intensity ratio in the range of this invention.

  It should be considered that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above embodiments and examples but by the scope of claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the scope of claims. .

The container manufactured by molding the aluminum foil of the present invention can be used for storage or packaging of food, medicine, etc., and can be used for a battery pack for storing an electrolyte and a current collector. You can also.

Claims (4)

  Iron is contained in an amount of 0.7% by mass to 1.7% by mass and has a thickness of 10 μm to 150 μm. In X-ray diffraction, (111) plane, (100) plane, (110) plane, and (311) The ratio of the diffraction intensity indicating the (100) plane to the total diffraction intensity, which is the sum of the diffraction intensities indicating each of the surfaces, is 30% to 50%, and the diffraction intensity indicating the (110) plane with respect to the total diffraction intensity Aluminum foil whose ratio is 15% or more and 40% or less.   A container manufactured by molding the aluminum foil according to claim 1.   The container manufactured by shape | molding the laminate material containing the aluminum foil of Claim 1, and a resin film. The container manufactured by shape | molding the laminate material containing the aluminum foil of Claim 1, a resin film, and a heat bonding layer.