JP5116255B2 - Packaging material and electrical / electronic structure member using aluminum alloy - Google Patents

Description

This invention relates to packaging materials and electrical and electronic structural members with excellent aluminum alloy in corrosion resistance, in particular, and a sufficient elongation to improve high strength and moldability, showing a better rolling resistance, beverage and food and packaging materials such as chemicals, it relates to electrical and electronic structural member such as a battery packaging material and battery electrodes.

  Among aluminum alloys, especially for weakly acidic food packaging materials containing soy sauce and salt, and for electronic materials that come into contact with the electrolyte, it has sufficient elongation to enhance its corrosion resistance and strength and formability. Therefore, aluminum alloys such as JIS (Japanese Industrial Standard) names 3003, 3004, 5052, 1N30, 8021, and 8079 having a thickness of about 6 to 200 μm are usually used. Table 1 shows typical compositions of these alloys.

  In these alloys, a corrosion phenomenon called pitting corrosion is generally likely to occur.

  In order to prevent this pitting corrosion, for example, JP-A-3-261549 (Patent Document 1) discloses a clad material in which a high-purity aluminum film is formed on the surface as a skin material. JP-A-60-221546 (Patent Document 2) discloses a technique for preventing pitting corrosion by adding zinc to an aluminum alloy. Further, JP-A-10-183283 (Patent Document 3) discloses an aluminum alloy clad material excellent in corrosion resistance using an aluminum alloy containing tin as a skin material.

  However, when high-purity aluminum is used as the skin material, since the high-purity aluminum is too soft, fine powder is likely to be generated at the time of molding, which causes a problem of contamination.

  Further, when zinc or tin is added, pitting corrosion can be prevented, but the material is totally corroded. For this reason, the amount of corrosion is large and it is not suitable for packaging materials such as food.

  Furthermore, the use of a clad material as a food packaging material is often unprofitable in terms of cost, such as difficulty in thin foil rolling.

  In addition, aluminum alloys used as packaging materials for beverages, foods, medicines, and the like require strength and formability, but those described in the above-mentioned publications are sufficient to satisfy these characteristics. There wasn't.

  Fields other than for packaging materials, that is, used in a thickness of 10 μm or less, for example, for building materials used as heat insulating materials, for machine parts, for electronic materials such as battery packaging materials and battery electrodes, for home use and for decoration Aluminum alloy foils are also required to have high corrosion resistance and high strength. However, aluminum alloys such as the above JIS names 3003, 3004, and 5052 have high work hardening during rolling, and it has been difficult to roll into foils having a thickness of 10 μm or less. In particular, in 3004 and 5052 aluminum alloys, it was practically impossible to obtain an aluminum alloy foil of 20 μm or less.

  For these thin foils, aluminum-iron alloys such as JIS names 8021 and 8079 shown in Table 1 are usually used. However, in these alloys, the presence of an aluminum-iron-based intermetallic compound causes a decrease in corrosion resistance and suppresses refinement of crystal grains for obtaining sufficient strength. Therefore, these aluminum alloys were insufficient in strength and were never satisfactory.

In addition, International Publication No. WO01 / 004369 (Patent Document 4) includes 0.0001 mass% or more and 0.03 mass% or less of copper, 0.0005 mass% or more and 0.2 mass% or less of silicon, An aluminum alloy containing 0.5% by mass or more and 4% by mass or less of manganese and 0.5% by mass or more and 3% by mass or less of iron and the balance containing aluminum and inevitable impurities is disclosed. However, although this alloy is superior in strength, formability and workability to conventional aluminum alloys, it does not sufficiently prevent pitting corrosion and general corrosion. For example, it has good corrosion resistance even in an electrolyte solution or a soy sauce stock solution. Could not be maintained.
Japanese Patent Laid-Open No. 3-261549 JP-A-60-221546 Japanese Patent Laid-Open No. 10-183283 International Publication No. WO01 / 004369 Pamphlet

Accordingly, the present invention has been made to solve the above-described problems, and the object of the present invention is to prevent pitting corrosion and overall corrosion without processing into the form of a clad material, and strength is to provide a packaging material and electrical and electronic structural members with excellent aluminum alloy in moldability and processability.

In order to solve the above problems, the present inventors have studied a result, when the iron with manganese is present, the intermetallic compound Al 6 _(Fe, Mn) or the like is formed on the other of the intermetallic compound Al 6 _Mn, In an acidic to strongly acidic environment, it has been found that this intermetallic compound Al ₆ (Fe, Mn) or the like extremely reduces the corrosion resistance of the aluminum alloy.

  Manganese increases the strength without impairing the corrosion resistance of the aluminum alloy, and by selecting an appropriate content and processing method, sufficient elongation to improve the formability and high to obtain a thin foil It was also found to be an element that can impart rollability.

  Furthermore, the addition of a small amount of chromium, titanium and zirconium does not impair the corrosion resistance of the aluminum alloy, increases the strength by refining the crystal grains, and selects an appropriate processing method to improve the formability. It has also been found that the element can provide sufficient elongation and high rollability to obtain a thin foil.

  Based on these findings, we have succeeded in developing an aluminum alloy excellent in corrosion resistance, strength, formability and rollability.

An aluminum alloy according to one aspect of the present invention, which has been made based on these findings, includes 0.1% by mass to 6% by mass of manganese, 0.001% by mass to 0.02% by mass of iron, and 0.0005 wt% 0.02 wt% or less of silicon, and a 0.0001 mass% or more 0.03% by mass or less of copper, the balance being aluminum and inevitable impurities.

  Preferably, the aluminum alloy of the present invention contains 0.0001% by mass or more and 0.01% by mass or less of copper, 0.001% by mass or more and 0.02% by mass or less of zinc, and 0.001% by mass or more and 0.001% by mass or more. 02% by mass or less of gallium.

  Further, an aluminum alloy according to another aspect of the present invention is the above-described aluminum alloy, wherein 0.01 mass% or more and 0.5 mass% or less of chromium, 0.01 mass% or more and 0.5 mass% or less. % Or less of titanium and 0.01% by mass or more and 0.5% by mass or less of zirconium.

  The packaging material according to the present invention is made of an aluminum alloy having any one of the above-described compositions, and has a thickness of 6 μm or more and 200 μm or less.

  The electrical / electronic structural member according to the present invention is made of an aluminum alloy having any one of the above-described compositions, and has a thickness of 4 μm or more and 1 mm or less.

  As described above, according to the present invention, an aluminum alloy having excellent corrosion resistance as well as strength, formability and rollability can be obtained, and a packaging material and an electrical / electronic structure member made of the aluminum alloy can be obtained.

  Hereinafter, the reason why each element is added, the range of the amount added, the conditions of the manufacturing method, and the like will be described in detail.

(1) Manganese (Mn): 0.1% by mass or more and 6% by mass or less Manganese is an element that improves the strength without greatly reducing the corrosion resistance of the aluminum alloy. If the manganese content is less than 0.1% by mass, sufficient strength cannot be obtained. Moreover, when the content rate of manganese exceeds 6 mass%, elongation and a moldability will fall. Therefore, it is necessary to make the manganese content 0.1% by mass or more and 6% by mass or less. In order to combine the corrosion resistance, strength, formability, and rollability of the aluminum alloy, it is more preferable that the manganese content is 1.0 mass% or more and 4.0 mass% or less.

(2) Iron (Fe): 0.001% by mass or more and 0.02% by mass or less Iron forms an aluminum-iron-manganese intermetallic compound together with the above-described manganese. The aluminum-iron-manganese-based intermetallic compound is represented by Al ₆ (Fe, Mn) or the like, and is different from the aluminum-manganese-based intermetallic compound Al ₆ Mn, for example, an acidic solution such as an electrolyte solution or a soy sauce stock solution, etc. In a strongly acidic environment, the corrosion resistance of the aluminum alloy is extremely reduced, causing pitting corrosion and general corrosion.

  In other words, when iron is present in an amount of 0.001% by mass or more, unless the manganese is limited to 6% by mass or less, it causes pitting corrosion and overall corrosion.

  When the iron content exceeds 0.02% by mass, the corrosion resistance is significantly reduced. The lower limit of the iron content is not particularly limited, but is usually about 0.001% by mass. This is because even if the iron content is less than 0.001% by mass, the above-described effect of improving the corrosion resistance is saturated, but the cost is increased. Preferably, the iron content is 0.01% by mass or less.

  In the present invention, as a method for adjusting the iron content to 0.02% by mass or less, for example, a high-grade primary electrolytic metal, a segregation method, or a high-purity aluminum metal by a three-layer electrolytic method is appropriately used. do it.

(3) Silicon (Si): 0.0005% by mass or more and 0.02% by mass or less If silicon is present in the aluminum alloy, the corrosion resistance of the aluminum alloy is significantly reduced in an acidic environment, and causes pitting corrosion. . Further, when the silicon content is reduced, the crystal grain size of the aluminum alloy is reduced. Thereby, the yield strength of the aluminum alloy, that is, the strength is increased, and the elongation of the aluminum alloy, that is, the formability can be improved. In order to exert these characteristics, it is necessary that the silicon content is 0.0005 mass% or more and 0.02 mass% or less. The silicon content of 0.0005% by mass or more is saturated even if the silicon content is less than 0.0005% by mass, the effect of improving the pitting corrosion resistance and the effect of increasing the formability and strength are saturated. On the other hand, the cost increases. Preferably, the silicon content is 0.1% by mass or less.

(4) Copper (Cu): 0.0001 mass% or more and 0.03 mass% or less Copper reduces the corrosion resistance of the aluminum alloy even if it exists in a trace amount in the aluminum alloy. Therefore, the copper content is set to 0.03% by mass or less. The reason why the copper content is set to 0.0001% by mass or more is that even if the copper content is less than 0.0001% by mass, the effect of improving the pitting corrosion resistance is saturated, but the cost is increased. Preferably, the copper content is 0.02 mass% or less, more preferably 0.01 mass% or less.

  Moreover, as an unavoidable impurity, when 0.001 mass% or more and 0.02 mass% or less zinc and 0.001 mass% or more and 0.02 mass% or less gallium are contained, Preferably, the content rate of copper Is 0.01 mass% or less, More preferably, it is 0.003 mass% or less.

(5) Chromium (Cr): 0.01% by mass or more and 0.5% by mass or less Chromium improves the strength of the aluminum alloy without significantly reducing the corrosion resistance of the aluminum alloy. If the chromium content is less than 0.01% by mass, the effect of improving the strength cannot be obtained sufficiently. If the chromium content exceeds 0.5% by mass, the formability is lowered. Therefore, it is necessary to make the chromium content 0.01% by mass or more and 0.5% by mass or less. In order to achieve excellent formability, the chromium content is preferably 0.25% by mass or less.

(6) Titanium (Ti): 0.01% by mass or more and 0.5% by mass or less Titanium improves the strength of the aluminum alloy without significantly reducing the corrosion resistance of the aluminum alloy. In particular, when titanium is added, a coarse aluminum-iron-manganese intermetallic compound that becomes a molding defect is refined. Thereby, toughness can be imparted to the aluminum alloy. When the content of titanium is less than 0.01% by mass, effects such as improvement in strength and imparting toughness cannot be obtained sufficiently. If the content of titanium exceeds 0.5% by mass, the formability is lowered. Therefore, the content of titanium needs to be 0.01% by mass or more and 0.5% by mass or less. Moreover, in order to further exhibit the above-described effects, the titanium content is preferably set to 0.25% by mass or less.

(7) Zirconium (Zr): 0.01% by mass or more and 0.5% by mass or less Zirconium also improves the strength without significantly reducing the corrosion resistance of the aluminum alloy, but this effect is more remarkable than chromium or titanium. . This is because the addition of zirconium is very effective in refining the recrystallized grains, and as a result, both improvement in strength and securing of elongation can be achieved and the rolling property does not deteriorate. If the zirconium content is less than 0.01% by mass, the above effects cannot be exhibited. If the zirconium content exceeds 0.5% by mass, the elongation decreases and the moldability deteriorates. In order to achieve excellent strength, elongation, and rollability, the zirconium content is preferably 0.35% by mass or less.

  As described above, according to the present invention, since the optimum amount of the above-described additive elements is added to aluminum, the recrystallized structure of the aluminum alloy becomes ultrafine. As a result, the strength and formability of the aluminum alloy can be improved at the same time, and the corrosion resistance is excellent enough to prevent pitting corrosion and overall corrosion by optimizing the manganese and iron contents. The characteristics of the aluminum alloy according to the present invention.

  The aluminum alloy of the present invention has a content that does not affect the above characteristics and effects, transition elements such as vanadium (V) and nickel (Ni), magnesium (Mg), boron (B), and gallium. Elements such as (Ga), zinc (Zn), and bismuth (Bi) may be included.

(8) Thickness of aluminum alloy for packaging material: 6 μm or more and 200 μm or less If the thickness of the aluminum alloy is less than 6 μm, the strength as a packaging material for food or the like cannot be maintained. Moreover, when thickness exceeds 200 micrometers, while shaping | molding as a packaging material becomes difficult, weight and cost increase. Therefore, the thickness of the aluminum alloy needs to be 6 μm or more and 200 μm or less. More preferably, the thickness of the aluminum alloy is 6 μm or more and 100 μm or less.

(9) Thickness of aluminum alloy for electrical / electronic structural member: 4 μm or more and 1 mm or less If the thickness of the aluminum alloy is less than 4 μm, the strength as an electrical / electronic structural member such as an electrode cannot be maintained. Moreover, when thickness exceeds 1 mm, while it becomes difficult to shape | mold as an electric-electronic structural member, weight and cost increase. Therefore, the thickness of the aluminum alloy needs to be 4 μm or more and 1 mm or less. More preferably, the aluminum alloy has a thickness of 10 μm or more and 500 μm or less.

  In order to make the thickness of the aluminum alloy within the above range, casting and rolling may be performed according to a normal method. Moreover, you may heat-process suitably.

  As described above, according to the present invention, it is possible to provide an aluminum alloy in which neither pitting corrosion nor overall corrosion occurs and the strength and elongation can be improved at the same time. Even if this aluminum alloy is not processed into the form of a clad material, it is processed into an aluminum alloy foil as it is and used as a packaging material and an electrical / electronic structural member, so that it has excellent corrosion resistance and has high formability and strength. An electronic structural member can be provided at low cost.

  In addition, the foil made of an aluminum alloy developed in the present invention is used not only for packaging materials and as electrical and electronic structural members, but also in all fields of thin foils that require corrosion resistance, that is, for building materials and machines as heat insulating materials. Sufficient effects can also be exhibited in the fields of parts, packaging for the purpose of preventing the deterioration of food and chemicals, batteries, fins, households and decorations.

  The above food includes seasonings such as soy sauce, miso, sauce, ketchup, mayonnaise, salt, butter, margarine and cheese, and includes any form from liquid to solid.

  Furthermore, the composition of this aluminum alloy is not limited to use in the field of foils and foils, but also exhibits a sufficient effect as a composition of a thicker plate material that requires corrosion resistance or a composition for powder metallurgy. It is.

  Examples of the present invention will be described below.

First, aluminum alloy plates having a thickness of 6 mm were prepared by melting and casting aluminum alloys having various compositions (composition Nos. 1 to 27) by a continuous casting method having a cooling rate of about 10 ³ ° C / second. In addition, composition No. 28 to 33 have compositions of JIS names 3003, 3004, 5052, 1N30, 8021, and 8079, respectively. These compositions are shown in Table 2.

  These aluminum alloy plates were heat-treated at a temperature of 400 ° C. for 5 hours, removed from the furnace, rolled into a foil having a thickness of 85 μm, and further heat-treated at a temperature of 350 ° C. for 10 hours.

The mechanical properties (proof stress [N / mm ² ] and Erichsen value [mm]) of the obtained aluminum alloy foil were measured. The Eriksen value was measured by an Erichsen test based on JIS Z 2247, which evaluates deformability (extrusion property) as one of the moldability evaluations.

  Further, in the following tests A to D, the obtained aluminum alloy foil was immersed in or brought into contact with four types of liquids (food and industrial materials) for 720 hours, and the corrosion state was observed.

  Test A: The above aluminum alloy foil was immersed or brought into contact with 3% by mass saline kept at a temperature of 50 ° C. for 720 hours.

  Test B: The above-described aluminum alloy foil was immersed or brought into contact with soy sauce maintained at a temperature of 50 ° C. (trade name Kikkoman Soy Sauce Noguchi, manufactured by Kikkoman Corporation) for 720 hours.

Test C: The above-described aluminum alloy foil was immersed or brought into contact with a 1 mol LiPF ₆ electrolyte kept at a temperature of 40 ° C. (the solvent was 1 part by weight of ethylene carbonate and 1 part by weight of diethylene carbonate) for 720 hours.

  Test D: The above aluminum alloy foil is immersed in a liquid prepared by dissolving cheese (trade name QBB natural cheese, manufactured by Rokko Butter Co., Ltd.) at a temperature of 50 ° C., and the cheese is re-solidified by returning to 30 ° C. After that, the temperature was kept at 30 ° C. for 720 hours.

  The measurement results were evaluated in three stages (◯, Δ, ×) in order from the one with good corrosion resistance.

  The above measurement results are shown in Table 3.

  From Tables 2 and 3, the composition No. The aluminum alloy foils 1 to 19 are superior in all of the proof stress, Erichsen value and corrosion resistance to the conventional aluminum alloys of JIS names 3003, 3004, 5052, 1N30, 8021 and 8079 (composition Nos. 28 to 33). I understand.

  In addition, composition No. having a composition outside the scope of the present invention. Also for the 20-27 aluminum alloy foils, the composition no. It can be seen that the aluminum alloy foils 1 to 19 are excellent in the comprehensive evaluation of the proof stress, the Erichsen value, and the corrosion resistance.

Further, conventionally, have been used as a thin foil for packaging material, yield strength of the aluminum alloy of JIS designations 8021,8079 are each a thickness 10 [mu] ^m, was 55N / mm 2, 35N / mm 2 approximately, moreover aluminum present invention Since it does not show any corrosion resistance as in the alloy, it can be seen that the aluminum alloy disclosed in the present invention is very effective for thin foils.

  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 or 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. .

  Since the aluminum alloy according to the present invention has excellent corrosion resistance and high formability and strength, it is not only used as a packaging material and as an electric / electronic structural member, but also in all fields of thin foils that require corrosion resistance, that is, heat insulation. It can be used in the fields of building materials, machine parts, packaging materials for the purpose of preventing the deterioration of food and chemicals, fin materials, household and decorative fields. In addition to the use in the above, it can be sufficiently used for a thicker plate material requiring corrosion resistance or for powder metallurgy.

Claims (8)

0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass % 0.03 and a mass% of copper, the balance being aluminum alloy consisting of aluminum and unavoidable impurities, the thickness is 6μm than 200μm following packaging. 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass and% 0.01 mass% copper, and 0.001 wt% 0.02 wt% or less of zinc, seen including a 0.001 wt% 0.02 wt% or less of gallium, the balance being aluminum And a packaging material having a thickness of 6 μm to 200 μm . 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass % To 0.03% by mass of copper, 0.01% to 0.5% by mass of chromium, 0.01% to 0.5% by mass of titanium, and 0.01% to 0. A packaging material comprising at least one selected from the group consisting of 5% by mass or less of zirconium , the balance being made of an aluminum alloy consisting of aluminum and inevitable impurities, and a thickness of 6 μm to 200 μm . 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass % To 0.01% by weight of copper, 0.001% to 0.02% by weight of zinc, 0.001% to 0.02% by weight of gallium, and 0.01% by weight or more. At least one selected from the group consisting of 0.5 mass% or less of chromium, 0.01 mass% or more and 0.5 mass% or less of titanium, and 0.01 mass% or more and 0.5 mass% or less of zirconium. A packaging material that includes an aluminum alloy that includes aluminum and inevitable impurities, and has a thickness of 6 μm to 200 μm. 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass An electrical and electronic structural member having a thickness of 4 μm or more and 1 mm or less, comprising an aluminum alloy composed of aluminum and unavoidable impurities. 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass and% 0.01 mass% copper, and 0.001 wt% 0.02 wt% or less of zinc, seen including a 0.001 wt% 0.02 wt% or less of gallium, the balance being aluminum And an electrical and electronic structural member having an thickness of 4 μm or more and 1 mm or less. 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass % To 0.03% by mass of copper, 0.01% to 0.5% by mass of chromium, 0.01% to 0.5% by mass of titanium, and 0.01% to 0. An electrical and electronic structural member comprising at least one selected from the group consisting of 5 mass% or less of zirconium , the balance being made of an aluminum alloy consisting of aluminum and inevitable impurities, and a thickness of 4 μm to 1 mm. 0.1 mass% or more and 6 mass% or less of manganese, 0.001 mass% or more and 0.02 mass% or less of iron, 0.0005 mass% or more and 0.02 mass% or less of silicon, and 0.0001 mass % To 0.01% by weight of copper, 0.001% to 0.02% by weight of zinc, 0.001% to 0.02% by weight of gallium, and 0.01% by weight or more. At least one selected from the group consisting of 0.5 mass% or less of chromium, 0.01 mass% or more and 0.5 mass% or less of titanium, and 0.01 mass% or more and 0.5 mass% or less of zirconium. An electrical and electronic structural member comprising an aluminum alloy consisting of aluminum and inevitable impurities and having a thickness of 4 μm to 1 mm.