JP2008000913A - Steel plates and cans for containers with excellent functionality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel plate for containers excellent in appearance, weldability, rust resistance and corrosion resistance, and a can body thereof.
SOLUTION: Average center roughness (Ra) 0.15 to 0.5 μm On the inner surface side of a steel plate, 1 to 20 μm adhesive layer, 1 to 100 μm aluminum foil or printing ink from the lower layer, and 1 to 20 μm. Steel plate for a container provided with the organic resin layer and its can. Further, on the inner surface side of the can of an average center roughness (Ra) 0.15 to 0.5 μm steel plate, Ni as a lower layer or Ni or Fe—Ni alloy is 10 to 1000 mg / m ² and Sn is 300 to 1500 mg / m ^2. the chromate film as the metal Cr 4~140mg / m ^2, Zr film intermediate processing layer composed from one or more of 1-500 mg / m ² as metallic Zr, adhesive layer 1 to 20 [mu] m, the 1~100μm A steel plate for containers and a can body provided with an aluminum foil or printing ink and an organic resin layer of 1 to 20 μm.
[Selection figure] None

Description

  The present invention relates to a steel sheet for containers and a can body thereof, which are excellent in appearance, weldability, rust resistance, and corrosion resistance, in particular, as container materials.

  Welding cans are made by wire-seam welding and have been put to practical use as retort beverages such as coffee and food cans. Steel plates for cans used in this type of welding can can be produced by the method described in JP-A-60-208494 (Patent Document 1), JP-A-60-13098 (Patent Document 2), etc. Steel plates plated with Sn are mainly used. The coated steel sheet was coated or laminated on the side corresponding to the inside of the plated steel plate except for the welded portion, and the coated surface or the printed sheet was printed on the side corresponding to the outer surface of the can except for the welded portion. The film is laminated. A width of several millimeters in the vicinity of the welded part is called a varnish-preventing part, but the coating and film are not laminated in order to ensure stable weldability and prevent the coating and film from being seized by welding heat. After painting and laminating the film, it is cut into a size corresponding to one can, and a welding can is manufactured through processes such as a welding process and a neck-flanging process.

Moreover, there are three reasons why Sn is used in the steel sheet for welding cans. One is to secure high-speed superior weldability that enables welding at high speed, and the second is the appearance with excellent metallic luster. The other is to secure the corrosion resistance of the corrosion resistance.
On the other hand, in wire seam welding, an alternating current is usually used, and a welding nugget is formed by the half wave. The interval between the welding nuggets depends on the AC frequency used and the welding speed (wire speed), and is generally set to about 0.8 to 1 mm. Also, if the current used is too low, sufficient welding strength cannot be obtained, and if it is too high, scattering due to overheating (overheating) occurs, and there is concern about iron elution into the contents. Must be set.

  In recent years, in order to improve welding quality, a welding method for narrowing the nugget interval to 0.5 mm or less has been performed. When the nugget interval is narrowed, the occurrence of scattering due to overheating can be suppressed, and the adjustment range of the set current can be further widened. However, when the nugget interval is narrowed, the welding current increases, so the amount of heat generated between the electrode and the steel sheet increases, and the phenomenon that the plated Sn scatters becomes prominent. The scattered Sn adheres and accumulates on the Z bar and tool near the welding head, and when it reaches a certain size, it falls to the welded part, resulting in poor welding. This welding failure can be improved by reducing the use of Sn or not using it at all. However, the appearance and corrosion resistance deteriorate, and rusting occurs at the varnish area near the welded part where the coating and film are not laminated. Since it becomes easy, the steel plate for containers which can ensure external appearance property, corrosion resistance, and rust resistance was calculated | required.

In order to cope with the above-mentioned problems, an invention for laminating aluminum foil has been made, and is described in Japanese Patent Application Laid-Open No. 2000-255666 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2002-79608 (Patent Document 4). Certainly, if these techniques are used, appearance and corrosion resistance can be secured, but the varnish portion near the welded portion cannot solve the problem of rusting. In addition, there is an invention of laminating an aluminum deposited film, which is described in Japanese Patent Application Laid-Open No. 2000-95248 (Patent Document 5) and Japanese Patent Application Laid-Open No. 62-286734 (Patent Document 6). Although it can give a certain appearance, it has not yet secured corrosion resistance and weldability.
JP 60-208494 A JP-A-60-13098 Japanese Patent Laid-Open No. 2000-255566 JP 2002-79608 A JP 2000-95248 A JP-A-62-286734

  As a method for solving the above problems, the present inventors can cover the entire surface of the steel sheet with aluminum foil without removing the varnish portion, and can prevent the film from being seized with stable weldability or welding. Invented the method. An adhesive is used for joining the aluminum foil and the steel plate. However, since the adhesive is an organic resin, the electrical conductivity is low and the weldability is not ensured. Moreover, although the steel plate which laminated | stacked aluminum foil at the time of welding can be inserted | pinched by the pressure of 40-60 daN, an adhesive bond layer can be destroyed to some extent and electrical conductivity can be improved, but it was inadequate practically. However, they found that the roughness of the steel sheet surface originally destroyed the adhesive layer with low electrical conductivity and exhibited electrical conductivity, and prevented stable weldability and seizure. Furthermore, it has been found that by combining an appropriate plating layer with an appropriate roughness, a more stable weldability and anti-seize effect can be exhibited, and the present invention has been achieved.

That is, the present invention
(1) Average center roughness (Ra) 0.15 to 0.5 μm An inner surface of the steel plate is provided with an adhesive layer of 1 to 20 μm, an aluminum foil of 1 to 100 μm, and an organic resin layer of 1 to 20 μm from the lower layer. Steel plate for containers.
(2) Average center roughness (Ra) 0.15 to 0.5 μm On the outer surface side of the steel plate, from the lower layer, 1 to 20 μm adhesive layer, 1 to 100 μm aluminum foil, printing ink layer, 1 to 20 μm organic A steel plate for containers provided with a resin layer.
(3) Average central roughness (Ra) 0.15 to 0.5 μm On the inner surface side of the steel plate, Ni or Fe—Ni alloy as Ni or Fe—Ni alloy is 10 to 1000 mg / m ² and Sn is 300 to 1500 mg / m from the lower layer. ² , an intermediate treatment layer composed of one or more of 1 to 500 mg / m ^{2 with} a chromium film as metal Cr and 4 to 140 mg / m ² , and a Zr film as metal Zr, an adhesive layer of 1 to 20 μm, 1 Steel plate for containers provided with -100 μm aluminum foil and 1-20 μm organic resin layer.
(4) Average center roughness (Ra) 0.15 to 0.5 μm On the outer surface side of the steel plate, Ni or Fe—Ni alloy as Ni or Fe—Ni alloy is 10 to 1000 mg / m ² and Sn is 300 to 1500 mg / m from the lower layer. ² , an intermediate treatment layer composed of one or more of 1 to 500 mg / m ^{2 with} a chromium film as metal Cr and 4 to 140 mg / m ² , and a Zr film as metal Zr, an adhesive layer of 1 to 20 μm, 1 Steel plate for containers provided with -100 μm aluminum foil, printing ink layer, and 1-20 μm organic resin layer.
(5) It exists in the can obtained using the steel plate for containers of any one of said (1)-(4).

  As described above, it has been clarified that the steel plate for containers and the can produced by the present invention have excellent appearance, weldability, rust resistance, and corrosion resistance.

Below, the steel plate for containers which was the effect | action of this invention, and was excellent in the external appearance property, weldability, rust resistance, and corrosion resistance, and its can body are demonstrated in detail.
The steel plate used in the present invention is manufactured through processes such as hot rolling, acid tip, cold rolling, annealing, and temper rolling from a normal steel slab manufacturing process. Among them, the roughness imparted to the steel sheet surface which is the content of the present invention, that is, the average center roughness (Ra) is controlled by controlling the rolling reduction and roll roughness of cold rolling and temper rolling. Ra can be controlled, but industrially, it is desirable to control Ra by temper rolling.

  When Ra applied to the steel plate is increased, the effect of breaking the upper adhesive layer is increased, the conductivity is gradually increased, and weldability is exhibited when Ra is 0.15 μm or more. When Ra is increased, the effect of improving weldability is also increased. However, when Ra is excessively large, the valley portion of the surface roughness becomes too large, and large bubbles that cause peeling when laminating the aluminum foil are formed. Occurs and sufficient adhesion cannot be obtained. Therefore, Ra needs to be 0.15 to 0.5 μm.

  An aluminum foil composed of three layers of an adhesive layer of 1 to 20 μm, an aluminum foil of 1 to 100 μm, and an organic resin layer of 1 to 20 μm is laminated on the steel sheet from the lower layer. There is no particular restriction on the manufacturing method of the aluminum foil composed of these three layers. For example, a known method such as coating an adhesive layer on one side of an aluminum foil and an organic resin layer on the other side may be used. If the adhesive layer of the aluminum foil is thin, sufficient adhesive ability cannot be exhibited, so the thickness must be 1 μm or more. Moreover, since laminating workability deteriorates when the thickness is increased, it is industrially disadvantageous.

The aluminum foil has an effect of exhibiting a barrier and metallic gloss appearance. When the thickness is less than 1 μm, the barrier property and gloss appearance are not sufficiently exhibited. Moreover, since it will be economically disadvantageous if thickness exceeds 100 micrometers, it is necessary to make the thickness of aluminum foil into 1-100 micrometers.
The outermost organic resin layer is applied to prevent corrosion and wrinkling of the aluminum foil. If the thickness is less than 1 μm, the aluminum layer is not sufficiently prevented from being corroded or wrinkled. Moreover, since it will be economically disadvantageous if thickness exceeds 20 micrometers, it is necessary to make thickness of an aluminum layer into 1-20 micrometers.

Furthermore, between the adhesive layer of the aluminum foil and the steel sheet, Ni as Ni or Fe—Ni alloy is 10 to 1000 mg / m ² , Sn is 300 to 1500 mg / m ² , and the chrome film is metal Cr. by the 4~140mg / m ^2, Zr coating an intermediate processing layer, characterized in that is composed of one or more 1-500 mg / m ² as metallic Zr, further more, weldability, adhesiveness, Corrosion resistance can be obtained.

Ni has the effect of improving corrosion resistance and weldability. If the amount of Ni is small, the effect of improving corrosion resistance and weldability cannot be obtained practically. Therefore, the amount of Ni needs to be 10 mg / m ² or more. Corrosion resistance and weldability increase as the amount of Ni increases, but if it exceeds 1000 mg / m ² , the effect is saturated, so it is necessary to economically make it 1000 mg / m ² or less. Ni can be applied by a known electroplating method by Ni or Fe—Ni alloy plating, but the excellent effect of Ni is not impaired even by Fe—Ni alloy plating.

Sn has the effect of improving corrosion resistance and weldability. If the amount of Sn is small, the effect of improving corrosion resistance and weldability cannot be obtained practically, so the amount of Sn needs to be 300 mg / m ² or more. Corrosion resistance and weldability increase with an increase in Sn content, but if it exceeds 1500 mg / m ² , the effect is saturated, so it is economically necessary to make it 1500 mg / m ² or less. Sn can be imparted by a known electroplating method, but the excellent effect of Sn is not impaired even if a molten tin treatment is performed after Sn plating to produce a Sn alloy layer.

The chromate film has the effect of improving corrosion resistance and adhesion. If the amount of the chrome film is small, the effect of improving the corrosion resistance and adhesion cannot be obtained practically. Therefore, the chrome film amount needs to be 4 mg / m ² or more as metal Cr. Corrosion resistance and adhesiveness increase with an increase in the amount of the chrome film, but when it exceeds 140 mg / m ² , the effect is saturated, so it is necessary to economically make it 140 mg / m ² or less. The chromium film is formed by a known electroplating method to form a chromium oxide single layer or a chromium film composed of two layers of oxide Cr and metal Cr. -The excellent effect of the coating is not impaired.

The Zr film has the effect of improving corrosion resistance and adhesion. If the amount of the Zr film is small, the effect of improving the corrosion resistance and adhesion cannot be obtained practically. Therefore, the amount of the Zr film needs to be 1 mg / m ² or more as the metal Zr. Corrosion resistance and adhesion increase as the amount of Zr film increases, but if it exceeds 500 mg / m ² , the effect is saturated, so it is necessary to economically make it 500 mg / m ² or less. Although the Zr film is formed as oxidized Zr or phosphoric acid Zr by a known electroplating method, the excellent effect of the Zr film is not impaired in any form.

Examples of the present invention and comparative examples are described below, and the results are shown in Table 1.
After cold rolling and annealing, a 0.17 mm thick steel sheet is prepared by degreasing and pickling an original sheet that has been temper-rolled at a rolling roll of Ra 0.34 μm and a reduction rate of 0.1 to 0.3%. And the steel plate which has an intermediate | middle layer of the following preparation methods (1)-(6) was produced.

(0) A steel plate that has not been treated.
(1) The steel plate which gave Ni plating using the watt bath was produced.
(2) A steel plate was prepared by performing Sn plating using a ferrostan bath and performing a molten tin treatment.
(3) Fe-Ni alloy plating was performed using a sulfuric acid-hydrochloric acid bath, and subsequently, Sn plating was performed using a ferrostan bath, and a steel sheet subjected to molten tin treatment was produced.
(4) A steel plate having a chromate film was prepared using a Sargent bath on the steel plates of (0) to (3).
(5) A steel sheet was prepared by applying a chromate film to the steel sheets of (0) to (3) using a dichromic acid bath.
(6) A Zr film was applied by cathodic electrolysis with a treatment solution in which Zr fluoride was dissolved in the steel plates of (0) to (3).

On the inner surface side of these steel plates, laminated aluminum foil with an olefin-based adhesive applied to one side of the aluminum foil and phenol resin on the opposite side, and acrylic resin against the printed aluminum foil on the outer surface side of the can Each printed laminated aluminum foil with an adhesive applied to the surface was laminated.
About this test material, the performance was evaluated about each item of (A)-(F) shown below.

(A) Minimum current value at which sufficient welding strength can be obtained by welding the test material by changing the current under the condition of welding wire speed 80 m / min using a weldable wire-sheath machine. Judging comprehensively from the width of the appropriate current range consisting of the maximum current value at which welding defects such as dust and welding spatter start to stand out, and the occurrence status of welding defects, 4 stages (◎: very good, ○: good, (△: Inferior, ×: Inability to weld)).

(B) Appearance Observe the can after welding, observe the print quality and gloss, 4 stages (◎: excellent print quality, gloss, ○: excellent print quality, but slightly inferior in gloss) , Δ: Print quality, gloss is slightly inferior, X: Print quality, gloss is inferior).

(C) A corrosion-resistant welded can body is prepared, filled with a coffee beverage, stored at 45 ° C. for 3 months, and the can body is corroded in four stages (◎: no corrosion observed, ○: practical use) Slight corrosion with no problem was observed, Δ: slight corrosion was observed, and X: corrosion was observed).

(D) The rust resistance test material is left in an atmosphere of repeated drying and wetting (humidity 90%, 2 hr⇔humidity 40%, 2 hr) for 2 months, and the rust generation status is divided into 4 levels (◎: no rusting, ○ : Slight rusting to the extent that there is no problem in practical use, Δ: Slight rusting, ×: Mostly rusting).

(E) END processing with the adhesion test material on the inner surface side, retort treatment at 125 ° C. for 30 minutes, and 4 steps of adhesion of aluminum foil (◎: no peeling, ○: slight peeling is observed) (Triangle | delta): Peeling is recognized, x has peeled in the majority).

表１に示すように、Ｎｏ．１〜１７は本発明例であり、Ｎｏ．１８〜２２は比較例である。比較例Ｎｏ．１８は缶内面側の接着剤層、アルミ箔および有機樹脂層がそれぞれ薄いために外観性、耐食性、耐錆性および密着性が悪い。比較例Ｎｏ．１９は平均中心粗さ（Ｒａ）が小さく、かつアルミ箔が薄いために溶接性、外観性、耐食性、耐錆性および密着性のいずれも悪い。比較例Ｎｏ．２０は平均中心粗さ（Ｒａ）が大きいために密着性が悪い。比較例Ｎｏ．２１は缶外面側の接着剤層およびアルミ箔が薄いために外観性および密着性が悪い。比較例Ｎｏ．２２は缶内面側および缶外面側の接着剤層およびアルミ箔が薄いために外観性、耐食性、耐錆性および密着性が悪い。これに対し、本発明例であるＮｏ．１〜１７はいずれも本発明の条件を満たしていることから、溶接性、外観性、耐食性、耐錆性および密着性のいずれも優れていることが分かる。


特許出願人 新日本製鐵株式会社
代理人 弁理士 椎 名 彊 他１

As shown in Table 1, no. Nos. 1 to 17 are examples of the present invention. 18-22 are comparative examples. Comparative Example No. No. 18 has poor appearance, corrosion resistance, rust resistance and adhesion because the adhesive layer, aluminum foil and organic resin layer on the inner surface of the can are thin. Comparative Example No. No. 19 has a low average center roughness (Ra) and a thin aluminum foil, and therefore has poor weldability, appearance, corrosion resistance, rust resistance, and adhesion. Comparative Example No. Since No. 20 has a large average center roughness (Ra), adhesion is poor. Comparative Example No. No. 21 has poor appearance and adhesion due to the thin adhesive layer and aluminum foil on the outer surface of the can. Comparative Example No. No. 22 has poor appearance, corrosion resistance, rust resistance and adhesion because the adhesive layer and the aluminum foil on the inner surface side and outer surface side of the can are thin. On the other hand, No. which is an example of the present invention. Since 1-17 satisfy | fills the conditions of this invention, it turns out that all of weldability, external appearance property, corrosion resistance, rust resistance, and adhesiveness are excellent.


Patent applicant: Nippon Steel Corporation
Attorney Attorney Shiina and others 1

Claims (5)

Average center roughness (Ra) 0.15 to 0.5 μm The inner surface of the steel plate was provided with an adhesive layer of 1 to 20 μm, an aluminum foil of 1 to 100 μm, and an organic resin layer of 1 to 20 μm from the lower layer. Characteristic steel plate for containers. Average center roughness (Ra) 0.15 to 0.5 μm On the outer surface side of the steel plate, 1-20 μm adhesive layer, 1-100 μm aluminum foil, printing ink layer, 1-20 μm organic resin layer from the lower layer. A steel plate for containers characterized by being provided. Average center roughness (Ra) 0.15 to 0.5 μm On the inner surface side of the steel plate, from the lower layer, Ni as the Fe or Ni—Fe alloy is 10 to 1000 mg / m ² , Sn is 300 to 1500 mg / m ² , chrome - the door coating metal Cr 4~140mg / m ^2, the intermediate processing layer composed of one or more 1-500 mg / m ² of Zr film as the metal Zr, adhesive layer 1 to 20 [mu] m, the 1~100μm A steel plate for containers, provided with an aluminum foil and an organic resin layer of 1 to 20 μm. Average center roughness (Ra) 0.15 to 0.5 μm On the outer surface side of the steel plate, Ni as a lower layer or Ni—Fe—Ni alloy is 10 to 1000 mg / m ² , Sn is 300 to 1500 mg / m ² , chrome - the door coating metal Cr 4~140mg / m ^2, the intermediate processing layer composed of one or more 1-500 mg / m ² of Zr film as the metal Zr, adhesive layer 1 to 20 [mu] m, the 1~100μm A steel plate for containers, provided with an aluminum foil, a printing ink layer, and an organic resin layer of 1 to 20 μm. A can obtained by using the steel plate for containers according to any one of claims 1 to 4.