JP5093797B2 - Steel plate for containers with excellent can processability - Google Patents

Description

  The present invention relates to a steel plate for containers excellent in drawing ironing, weldability, corrosion resistance, paint adhesion, and film adhesion, in particular, as a can-making material.

  Metal containers used for beverages and foods are roughly classified into two-piece cans and three-piece cans. A two-piece can represented by a DI can is squeezed and ironed, then painted on the inner surface of the can and painted and printed on the outer surface of the can. The three-piece can is coated on the surface corresponding to the inner surface of the can and printed on the surface corresponding to the outer surface of the can, and then the can body is welded.

  In any type of can, a coating process is indispensable before and after canning. Solvent-based or water-based paints are used for painting, followed by baking. In this painting process, waste (such as waste solvents) resulting from the paint is discharged as industrial waste, and exhaust gas (mainly Carbon dioxide) is released to the atmosphere. In recent years, efforts have been made to reduce these industrial waste and exhaust gas for the purpose of protecting the global environment. Among these, the technique of laminating films as an alternative to painting has attracted attention and has spread rapidly.

  So far, in the two-piece can, there have been provided a large number of methods for producing a can in which a film is laminated and made, and related inventions. For example, Japanese Patent No. 1571783 (Patent Document 1) “Manufacturing Method of Squeezed Ironing Bowl”, Japanese Patent No. 1670957 (Patent Document 2) “Squeezed Ironing Bowl”, Japanese Patent Laid-Open No. 2-263523 (Patent Document 3) “ A method for producing a thinned deep-drawn can ”, Japanese Patent No. 1601937 (Patent Document 4)“ Coated steel sheet for drawn irons ”.

  In addition, in a three-piece can, Japanese Patent Laid-Open No. 3-236955 (Patent Document 5) “Three-piece Can Film Laminated Steel Band and its Manufacturing Method”, Japanese Patent Laid-Open No. 5-124648 (Patent Document 6) “On the outer surface of the can "Three-piece cans having a multilayer organic coating", JP-A-5-111979 (Patent Document 7) "Three-piece can steel plates having a striped multilayer organic coating", JP-A-5-147181 (Patent Document 8) “Production method of three-piece can striped laminated steel sheet”.

On the other hand, in many cases, a chromate film subjected to electrolytic chromate treatment is used for a steel sheet used as a base of a laminate film. The chromate film has a two-layer structure, and a hydrated Cr oxide layer is present on the metal Cr layer. Therefore, the laminate film (adhesive layer in the case of a film with an adhesive) ensures adhesion to the steel sheet through the hydrated Cr oxide layer of the chromate film. Although the details of the mechanism of this adhesion development are not clarified, it is said to be a hydrogen bond between a hydroxyl group of hydrated Cr oxide and a functional group such as a carbonyl group or an ester group of a laminate film.
Japanese Patent No. 1571783 Japanese Patent No. 1670957 JP-A-2-263523 Japanese Patent No. 1601937 Japanese Patent Laid-Open No. 3-236554 JP-A-5-124648 JP-A-5-111979 JP-A-5-147181

  Although the above-mentioned invention certainly has the effect of greatly advancing the conservation of the global environment, on the other hand, in the beverage container market, cost and quality competition with materials such as PET bottles, bottles and paper have intensified in recent years. In addition, for the above-mentioned steel sheet for laminated containers, it is possible to achieve superior can-making processability, especially film adhesion, while ensuring excellent adhesion and corrosion resistance for the conventional coating application. , Processed film adhesion, corrosion resistance, etc. have come to be required.

  As a result of diligent research on the use of the Zr film as a new film that replaces the chromate film, the present inventors have found that the Zr film or a Zr film obtained by combining a Zr film with a phosphate film or a phenol resin film is painted or laminated. The present inventors have found that a strong covalent bond is formed, and that excellent can processability can be obtained over the conventional chromate film.

That is, the present invention
(1) a composite in at least the steel sheet one side, the metal Zr amount 1-500 mg / m ² of Zr, the phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the amount of P The steel plate for containers which was excellent in the can-making process characteristic which gave the coated film | membrane by the cathodic electrolysis process .

(2) at least on the steel sheet one side, Ni and the 10 to 1000 mg / m ^2, Sn has a surface treatment layer containing one or more 80~6000mg / m ² as metallic Sn as metal Ni, metal Zr content thereon can manufacturing in the 1-500 mg / m ² of Zr, a film that combines phenolic resin 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the P content was applied by cathodic electrolysis treatment Steel plate for containers with excellent processing characteristics.

(3) at least on the steel sheet one side, Ni and the 10 to 1000 mg / m ^2, Sn has a surface treatment layer containing one or more 80~6000mg / m ² as metallic Sn as metal Ni, metal Zr content thereon can manufacturing in the 20 to 500 mg / m ² of Zr, a film that combines phenolic resin 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the P content was applied by cathodic electrolysis treatment Steel plate for containers with excellent processing characteristics.

(4) the composite to at least the steel sheet one side, the metal Zr amount 20 to 500 mg / m ² of Zr, the phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the amount of P The steel plate for containers which was excellent in the can-making process characteristic which gave the coated film | membrane by the cathodic electrolysis process .

  As described above, it is clear that the steel sheet for laminate containers manufactured by the present invention and excellent in can-making process has excellent drawing ironing, weldability, corrosion resistance, paint adhesion, and film adhesion. It was.

  Below, the steel plate for containers excellent in can manufacturing process which is an effect | action of this invention is demonstrated in detail. The original plate used in the present invention is not particularly restricted, and usually a steel plate used as a container material is used. There are no particular restrictions on the manufacturing method and material of the original plate, and the original plate is manufactured through steps such as hot rolling, acid tip, cold rolling, annealing, temper rolling, etc. from a normal slab manufacturing process. A surface treatment layer containing one or more of Ni and Sn is applied to the original plate, but the method of applying is not particularly restricted. For example, a known technique such as an electroplating method, a vacuum evaporation method, or a sputtering method may be used, and a heat treatment for providing a diffusion layer may be combined. Further, even if Ni is plated with Fe—Ni alloy, the essence of the present invention is not changed.

In the surface treatment layer containing one or more of Ni and Sn applied in this way, Ni is regulated to 10 to 1000 mg / m ² as metal Ni and Sn is regulated to 80 to 6000 mg / m ² as metal Sn. Sn exhibits excellent workability and weldability. This effect is required to be 80 mg / m ² or more as metal Sn. In order to ensure sufficient weldability, it is desirable to apply 200 mg / m ² or more, and in order to ensure sufficient workability, it is desirable to apply 1000 mg / m ² or more.

As the Sn adhesion amount increases, the improvement effect of excellent workability and weldability of Sn increases, but if it is 6000 mg / m ² or more, the improvement effect is saturated, which is economically disadvantageous. Therefore, the amount of Sn deposited needs to be 6000 mg / m ² or less as metallic Sn. Further, by performing a reflow treatment after Sn plating, an Sn alloy layer is formed, and the corrosion resistance is further improved.

Ni exerts its effects on paint adhesion, film adhesion, corrosion resistance, and weldability. For this purpose, Ni of 10 mg / m ² or more is necessary as metal Ni. With an increase in the amount of Ni deposited, the improvement effect of excellent film adhesion, corrosion resistance and weldability of Ni increases. However, if it is 1000 mg / m ² or more, the improvement effect is saturated, which is economically disadvantageous. Therefore, the adhesion amount of Ni is regulated to 10 mg / m ² or more and 1000 mg / m ² or less as metal Ni.

  A Zr film, a phosphoric acid film, and a phenol resin film, which are the essence of the present invention, are applied to the upper layer of the surface treatment layer containing one or more of these Ni and Sn. Methods for applying these films include a method of immersing a steel plate in an acidic solution in which Zr ions, phosphate ions, and low molecular weight phenolic resins are dissolved, and a method of performing cathodic electrolysis. Since various films are formed by etching, the adhesion becomes non-uniform, and the processing time becomes longer, which is disadvantageous for industrial production.

  On the other hand, in the cathode electrolysis treatment, a uniform film can be treated for a short time of several seconds to several tens of seconds, combined with forced charge transfer, surface cleaning by hydrogen generation at the steel plate interface, and adhesion promotion effect by pH increase. Therefore, it is extremely advantageous industrially. Accordingly, cathodic electrolysis is desirable for the application of the Zr film, phosphoric acid film, and phenol resin film of the present invention. In addition, when tannic acid is added to an acidic solution used for immersion treatment or cathodic electrolysis, tannic acid is combined with Fe, and a film of Fe tannic acid is formed on the surface, thereby improving rust resistance and adhesion. Therefore, depending on the application, the treatment may be performed in a solution to which tannic acid is added.

  The Zr film has excellent practical characteristics even when used alone, but the phosphoric acid film and the phenol resin film have sufficient practical performance with only a certain degree of effect even when used alone. Not. However, a film in which a phosphate film and a phenol resin film are combined exhibits excellent practical performance. In addition, when the Zr film is combined with one or more of a phosphoric acid film or a phenol film, a further excellent practical performance is exhibited.

The role of the Zr film is to ensure corrosion resistance and adhesion, particularly processing adhesion. The Zr coating is composed of a Zr compound such as Zr oxide, hydroxide Zr, Zr fluoride, Zr phosphate, or a composite coating thereof, and these Zr compounds have excellent corrosion resistance and adhesion. Therefore, when the Zr film has a metal Zr amount of 1 mg / m ² or more, the corrosion resistance and adhesion start to improve. However, in order to ensure a stable and practical level of corrosion resistance and adhesion, 20 mg / m ² or more is preferable.

Furthermore, when the amount of Zr film increases, the effect of improving corrosion resistance and adhesion also increases, but when the amount of Zr film exceeds 500 mg / m ^{2 in} terms of metal Zr, the Zr film becomes too thick and the adhesion of the Zr film itself deteriorates. In addition, the electrical resistance increases and the weldability deteriorates. Therefore, the Zr film adhesion amount needs to be ¹ to 500 mg / m ² in terms of metal Zr amount.

The role of the phosphoric acid film is to ensure corrosion resistance and adhesion, particularly processing adhesion. The phosphate film is composed of a film such as Fe phosphate, Sn phosphate, Ni phosphate, Zr phosphate, phosphate-phenol resin film or a composite film of these formed by reacting with the base. The phosphoric acid film has excellent corrosion resistance and adhesion. Therefore, when the phosphoric acid film increases, the corrosion resistance and adhesion begin to improve, and when the P amount is 0.1 mg / m ² or more, a practically satisfactory level of corrosion resistance and adhesion are secured.

Furthermore, when the amount of phosphoric acid film increases, the effect of improving corrosion resistance and adhesion also increases. However, when the amount of phosphoric acid film exceeds 100 mg / m ² in terms of P amount, the phosphoric acid film becomes too thick and adhesion of the phosphoric acid film itself is increased. As a result, the electrical resistance increases and the weldability deteriorates. Therefore, it is necessary that the phosphoric acid film adhesion amount is 0.1 to 100 mg / m ² in terms of P amount.

The role of the phenolic resin film is to ensure adhesion, particularly processing adhesion. Since the phenol resin itself is an organic substance, it has excellent adhesion to paints and laminate films. When the surface treatment layer undergoes processing that greatly deforms, the surface treatment layer itself may be coherently broken due to the processing, and adhesion may deteriorate. However, phenolic resins are processed adhesion of Zr film and phosphate film. Has the effect of remarkably improving. Therefore, when the phenol resin film increases, the adhesiveness starts to improve. When the C amount is 0.1 mg / m ² or more, a practically satisfactory level of adhesiveness is secured.

Furthermore, when the amount of the phenol resin film increases, the effect of improving the adhesion also increases. However, when the amount of the phenol resin film exceeds 100 mg / m ² in terms of the C amount, the electrical resistance increases and the weldability deteriorates. Therefore, it is necessary that the phosphoric acid film adhesion amount is 0.1 to 100 mg / m ² in terms of C amount.

Hereinafter, Examples and Comparative Examples of the present invention will be described, and the results are shown in Table 1.
In the following treatment method, a surface treatment layer was applied on a steel plate having a thickness of 0.17 to 0.23 mm using the methods (0) to ( 3 ).
(Treatment method 0) After cold rolling, a steel sheet was prepared by degreasing and pickling the annealed and pressure-adjusted original sheet.

(Treatment method 1 ) After cold rolling, the annealed and regulated original sheet was degreased, pickled, and then Ni-plated using a Watt bath to prepare a Ni-plated steel sheet.
(Treatment method 2 ) After cold rolling, annealed and pressure-controlled original sheet is degreased, pickled, plated with Sn using a ferrostan bath, and then subjected to reflow treatment to obtain a Sn-plated steel sheet having a Sn alloy layer Produced.

(Treatment method 3 ) After cold rolling, the annealed and regulated original plate was degreased, pickled, and then subjected to Sn-Ni alloy plating using a sulfuric acid-hydrochloric acid bath to prepare Ni and Sn plated steel plates.

After the surface treatment layer was applied by the above treatment, a Zr film, a phosphoric acid film, and a phenol resin film were applied by the following treatment methods ( 4 ) to ( 6 ).
(Treatment method 4 ) The steel sheet was immersed in a treatment solution in which Zr fluoride was dissolved, and after cathodic electrolysis, it was dried to give a Zr film.
(Treatment method 5 ) The steel sheet was immersed in a treatment solution in which Zr fluoride, phosphoric acid, and a phenol resin were dissolved, and after cathodic electrolysis, dried to give a Zr film, a phosphate film, and a phenol resin film.

(Treatment method 6 ) The steel sheet was immersed in a treatment solution in which phosphoric acid and a phenol resin were dissolved, and after cathodic electrolysis, it was dried to give a phosphoric acid film and a phenol resin film.

About the test material which performed said process, the performance evaluation about each item of (A)-(F) shown below was performed.
(A) PET film having a thickness of 20 μm is laminated at 200 ° C. on both sides of the workability test material, canned processing by drawing and ironing is performed in stages, and molding is performed in four stages (◎: very good, ○ : Good, Δ: wrinkles were observed, x: fractured and unworkable).

(B) Using a weldable wire seam welder, the current is changed under the conditions of a welding wire speed of 80 m / min, the test material is welded, and the minimum current value that provides sufficient welding strength, dust and welding spatter, etc. 4 steps (◎: very good, ○: good, △: inferior, ×) comprehensively judged from the wide range of the appropriate current range consisting of the maximum current value at which the welding defect starts to become noticeable and the occurrence state of the welding defect : Weldability was evaluated).

(C) Laminate a PET film having a thickness of 20 μm on both surfaces of the film adhesion test material at 200 ° C., squeeze and iron it to produce a can body, perform a retort treatment at 125 ° C. for 30 minutes, The peeling state of the film was evaluated in four stages (◎: no peeling at all, ○: very slight peeling with no practical problem, Δ: slight peeling, ×: peeling at most).

(D) An epoxy-phenol resin is applied to the paint adhesion test material, baked at 200 ° C. for 30 minutes, and then cut off at a depth of 1 mm to reach the iron core, and peeled off with tape. Evaluation was made at the stage (（: no peeling at all, ○: slight peeling at a practical level, Δ: slight peeling, ×: peeling at most).

(E) After applying an epoxy-phenolic resin to the corrosion resistance test material and baking at 200 ° C. for 30 minutes, put a crosscut at a depth reaching the base iron, and mix 1.5% citric acid-1.5% salt In a test solution consisting of: 45 ° C for 72 hours, washed, dried, and then peeled off from the tape. There are 4 levels of cross-cut corrosion under the coating and flat corrosion (◎: under-corrosion corrosion) Not recognized, ○: Slight under-coating corrosion to the extent that there is no practical problem is observed, Δ: Corrosion under micro-corrosion and slight corrosion is observed in the flat plate part, ×: Severe corrosive under-coating corrosion and flat plate The corrosion was recognized in the part) and evaluated.

(F) 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, (Circle): There was very slight rusting to the extent that there is no problem in practical use, (triangle | delta): There was slight rusting, and x: Rust was mostly evaluated.

表１に示すように、Ｎｏ．１〜７は本発明例であり、Ｎｏ．８〜９は比較例である。比較例Ｎｏ．８はＺｒ付着量が低く、しかもリン酸皮膜、フェノール樹脂皮膜もないことから、加工性、溶接性、フィルム密着性、塗料密着性、耐食性および耐錆性のいずれも悪い。また、比較例Ｎｏ．９は鋼板にＮｉ層を形成しているが、そのＮｉ量が低く、かつリン酸皮膜およびフェノール樹脂皮膜の付着量がいずれも低いために、加工性が劣り、かつ溶接性、フィルム密着性、塗料密着性、耐食性および耐錆性のいずれも悪い。
これに対して、本発明例であるＮｏ．１〜７はいずれも本発明の条件を満たしていることから、加工性、溶接性、フィルム密着性、塗料密着性、耐食性および耐錆性のいずれも優れていることが分かる。

As shown in Table 1, no. 1-7 is an example of the present invention, No. 8 to 9 are comparative examples. Comparative Example No. Since No. 8 has a low Zr adhesion amount and no phosphoric acid film or phenol resin film, all of workability, weldability, film adhesion, paint adhesion, corrosion resistance and rust resistance are poor. Comparative Example No. No. 9 has a Ni layer formed on the steel sheet, but its Ni amount is low, and since both the phosphoric acid film and the phenolic resin film are low in adhesion, workability is inferior, and weldability, film adhesion, Paint adhesion, corrosion resistance and rust resistance are all poor.
On the other hand, No. which is an example of the invention. Both 1-7 from that meets the conditions of the present invention, workability, weldability, film adhesion property, coating adhesion, that is none of the corrosion resistance and rust resistance superior seen.

Claims (4)

At least on the steel sheet one side of 1-500 mg / m ² of metal Zr content Zr, the composite was coating the phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the amount of P Steel plate for containers with excellent can-making characteristics imparted by cathodic electrolysis . At least on the steel sheet one side, Ni and the 10 to 1000 mg / m ^2, Sn has a surface treatment layer containing one or more 80~6000mg / m ² as metallic Sn as metal Ni,. 1 to a metal Zr content thereon 500 mg / m ² of Zr, the can-processing characteristics of the film obtained by combining a phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the P content imparted by cathodic electrolysis treatment Excellent steel plate for containers. At least on the steel sheet one side, Ni and having a surface treatment layer containing one or more 80~6000mg / m ² of 10 to 1000 mg / m ^2, Sn as Sn metal as metal Ni,. 20 to a metal Zr content thereon 500 mg / m ² of Zr, the can-processing characteristics of the film obtained by combining a phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the P content imparted by cathodic electrolysis treatment Excellent steel plate for containers. At least on the steel sheet one side of 20 to 500 mg / m ² of metal Zr content Zr, the composite was coating the phenolic resin of 0.1-100 mg / m ² with phosphoric acid and the C content of 12 -100 mg / m ² in the amount of P Steel plate for containers with excellent can-making characteristics imparted by cathodic electrolysis .