TWI513828B - Steel sheet for containers - Google Patents

Description

Steel plate for containers

The present invention relates to a steel sheet for containers.

For steel sheets for containers (surface-treated steel sheets for cans), Sn-plated steel sheets called "tinplates" have been widely used since the past. The Sn-plated steel sheet is usually obtained by immersing a steel sheet in an aqueous solution containing a hexavalent chromium compound such as dichromic acid, or by subjecting it to a chromate treatment such as electrolytic treatment in the solution, on the Sn plating surface. A chromate film is formed.

However, based on current environmental problems, the action of restricting the use of Cr has been carried out in various fields, and even if the steel sheet for containers is proposed, many treatment techniques are proposed instead of chromate treatment.

For example, Patent Document 1 discloses that "no resin is used, and resin adhesion is excellent" ([0013]), "characterized to have a mold containing Zr and O on at least one side of a metal plate, and the film F is A surface-treated metal sheet of less than 0.1 mg/m ² per surface" ([Request Item 1]), and "metal plate" referred to herein as "plated Sn steel sheet" ([Request Item 3]).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-184630

In recent years, the demand for aesthetics by consumers has increased, and various characteristics required for steel sheets for containers have been further improved.

The inventors of the present invention further examined the steel sheet for containers (surface-treated metal sheets) disclosed in Patent Document 1. As a result, it has been found that when the resin such as a PET film is laminated and subjected to a retort treatment, the adhesion to the resin film (hereinafter also referred to as "resin adhesion") is insufficient.

Further, the inventors of the present invention have found that when a coating film is formed on a steel sheet for a container by using an epoxy phenol-based paint, it is immersed in tomato juice under specific conditions, and the coating film is peeled off and corrosion resistance such as rust is deteriorated.

The present invention has been made in view of the above problems, and an object thereof is to provide a steel sheet for a container which is excellent in resin adhesion and corrosion resistance.

As a result of conducting a positive review to achieve the above object, the inventors of the present invention have found that a specific amount of a specific component is contained in a coating film for a steel sheet for a container, whereby both resin adhesion and corrosion resistance are improved, thereby completing the present invention. .

That is, the present invention provides the following (1) to (4).

(1) A steel sheet for a container, comprising: a plated steel sheet containing a plating layer covering at least a part of a Sn layer on a surface of the steel sheet; and a container disposed on a surface of the plated steel sheet on a surface of the plating layer side In the steel sheet, the film contains Zr, Ti, and cerium oxide, and the Zr conversion amount of each surface of the plated steel sheet of the film is 1 to 40 mg/m ² , and the Ti amount of each surface of the plated steel sheet is converted. It is more than 0.5 mg/m ² and less than 10 mg/m ² , and the Si conversion amount per side of the above-mentioned plated steel sheet is 1 to 40 mg/m ² .

(2) The steel sheet for a container according to the above aspect, wherein the surface of the plated steel sheet of the film has a Ti conversion amount of more than 3 mg/m ² and less than 10 mg/m ² .

(3) The steel sheet for a container according to the above aspect (1) or (2), wherein an atomic ratio (Ti/Zr) of Ti to Zr on the outermost surface of the film opposite to the side of the plated steel sheet is 0.05 to 2.0, The atomic ratio (Si/Zr) of Si to Zr is 0.1 to 3.0.

The steel sheet for a container according to any one of the above aspects, wherein the plating layer further contains a layer selected from the group consisting of a Ni layer, a Ni-Fe alloy layer, an Fe-Sn alloy layer, and Fe-Sn. At least one layer of the group consisting of -Ni alloy layers.

According to the invention, it is possible to provide a steel sheet for a container which is excellent in resin adhesion and corrosion resistance.

1‧‧‧Steel plates for containers

2‧‧‧film

3‧‧‧ cut parts of steel plate

4‧‧‧ weights

5‧‧‧ peel length

Figure 1 is a schematic diagram illustrating a 180 degree peel test.

[container steel plate]

The steel sheet for containers of the present invention has a plated steel sheet and a film disposed on the side surface of the plating layer of the plated steel sheet. Further, since the film contains a specific amount of Zr and Ti and contains a specific amount of cerium oxide, it is excellent in resin adhesion and corrosion resistance.

Hereinafter, specific examples of the plated steel sheet and the film will be described in detail. First, the state of the plated steel sheet will be described in detail.

<plated steel plate>

The plated steel sheet has a steel sheet and a plating layer covering at least a part of the surface of the steel sheet, and the plating layer contains at least a Sn layer. Hereinafter, the state of the steel plate and the plating layer will be described in detail.

(steel plate)

The type of the steel sheet is not particularly limited, and a steel sheet (for example, a low carbon steel sheet or an extremely low carbon steel sheet) which is generally used as a container material can be used. The method for producing the steel sheet, the material, and the like are not particularly limited, and are subjected to steps such as hot rolling, pickling, cold rolling, blunt, quenching and tempering, and the like after the usual steel sheet manufacturing step.

The steel plate is formed by using a nickel (Ni) layer on its surface as needed. A plating layer containing a Sn layer to be described later may be formed on the Ni-containing layer. By applying Sn plating to a steel sheet having a Ni-containing layer, a plating layer containing island-like Sn can be formed to improve the weldability.

The Ni-containing layer may be any nickel, and examples thereof include a Ni plating layer, a Ni-Fe alloy layer, and the like.

The method of imparting the Ni-containing layer to the steel sheet is not particularly limited, and examples thereof include a conventional plating method. Further, when the Ni-Fe alloy layer is provided as the Ni-containing layer, the Ni-Fe alloy layer can be formed by electroplating to give Ni on the surface of the steel sheet and then aligning the Ni diffusion layer by burning.

The amount of Ni in the Ni-containing layer is not particularly limited, and is preferably from 50 to 2,000 mg/m ² in terms of Ni per side. If it is within the above range, the cost side is also advantageous.

(plating layer)

The plated steel sheet has a plating layer containing a Sn layer on at least a part of the surface of the steel sheet. The plating layer may be provided on at least one side of the steel sheet, or may be provided on both sides.

The amount of Sn deposited on each side of the plated steel sheet is preferably from 0.1 to 15.0 g/m ² . When the Sn adhesion amount is within the above range, the steel sheet for a container is more excellent in corrosion resistance, and is preferably 0.2 to 15.0 g/m ² , and more preferably 1.0 to 15.0 g/m in terms of excellent workability. ² .

Further, the Sn adhesion amount can be measured by surface analysis using a gas amount method or fluorescent X-ray. In the case of fluorescent X-rays, a Sn adhesion amount sample having a known amount of Sn can be used, and a correction line related to the amount of Sn can be specified in advance, and The relative amount of Sn is specified by the same correction line.

The plating layer covers at least a portion of the surface of the steel sheet, and may be a continuous layer or a discontinuous island shape.

As the plating layer, in addition to the plating layer formed by the Sn layer obtained by plating Sn, Sn is heated and melted by heating or the like after Sn plating, and is obtained in the lowermost layer of the Sn layer (Sn layer/ A portion of the steel sheet interface forms a plating layer of the Fe-Sn alloy layer.

Further, the plating layer also includes Sn plating on a steel sheet having a Ni-containing layer on the surface, and heating and melting the tin by electric heating or the like, and partially forming on the lowermost layer (Sn layer/steel plate interface) of the Sn layer. A plating layer such as an Fe-Sn-Ni alloy layer or an Fe-Sn alloy layer.

Further, in the present invention, the Ni-containing layer (Ni layer, Ni-Fe alloy layer) is also included in the plating layer of the plated steel sheet.

The method for producing the plating layer is exemplified by a conventional method (for example, an electroplating method or a method of immersing in molten Sn for plating).

For example, a tin phenolsulfonate plating bath, a tin methane sulfonate plating bath, or a halogen-based tin plating bath is used so that the amount of adhesion per surface becomes a specific amount (for example, 2.8 g/m ² ). After electroplating on the surface of the steel sheet, it is heat-melted at a temperature equal to or higher than the melting point of Sn (231.9 ° C) to produce Fe-Sn in the lowermost layer (Sn layer/steel plate interface) of the Sn layer (Sn layer). A plating layer made of an alloy layer. When the heat-melting treatment is omitted, a plating layer (Sn layer) of the Sn elemental body can be produced.

Further, when the steel sheet has a Ni-containing layer on its surface, it is plated on the Sn single body after the Sn plating on the Ni-containing layer and then subjected to heat-melting treatment. The lowermost layer (Sn layer/steel plate interface) of the cladding layer (Sn layer) forms an Fe-Sn-Ni alloy layer, an Fe-Sn alloy layer, or the like.

<film>

The film system is disposed on the surface of the plating layer side of the plated steel sheet.

The film contains Zr, Ti and cerium oxide as its constituents. First, the following components will be described in detail, and then the formation method of the film will be described in detail.

(Zr, Ti and Si)

The film contains Zr (zirconium element), and the Zr conversion amount (hereinafter also referred to as "Zr adhesion amount") on each side of the plated steel sheet is 1 to 40 g/m ² . When the Zr adhesion amount is within the above range, the steel sheet for a container is excellent in resin adhesion and corrosion resistance. Among them, it is preferably from 1 to 25 m/m ² for reasons of excellent cost performance.

When the Zr adhesion amount is less than 1 mg/m ² , the resin adhesion and the corrosion resistance are inferior. Further, even if the Zr adhesion amount exceeds 40.0 g/m ^{2 , the} performance is not a problem, but the cost of the treatment liquid for ensuring the adhesion amount increases, and the cost increases due to the high current density.

The film contains Ti (titanium element), and the Ti-conducting amount (hereinafter also referred to as "Ti adhesion amount") on each side of the plated steel sheet is more than 0.5 mg/m ² and less than 10 mg/m ² . When the Ti adhesion amount is within the above range, the steel sheet for a container is excellent in resin adhesion. Further, from the viewpoint of further excellent resin adhesion, it is preferably more than 3 mg/m ² and less than 10 mg/m ² .

When the Ti adhesion amount is 0.5 mg/m ² or less, the resin adhesion is inferior. Moreover, even if the Ti adhesion amount is 10 mg/m ² or more, there is no problem in performance, but the cost of the treatment liquid for ensuring the adhesion amount increases, and the cost increases due to the high current density.

Furthermore, the film contains cerium oxide. By containing the film In the cerium oxide, it is considered that a moderately uneven shape is formed on the film, and the resin for the container is excellent in resin adhesion.

Further, the cerium oxide represented by the composition formula SiO ₂ has an amorphous shape and a spherical shape, but the cerium oxide contained in the film is preferably spherical cerium oxide. By using the colloidal ceria in which spherical cerium oxide is dispersed as the Si component in the treatment liquid described later, it is considered that the spherical cerium oxide can be contained in the film while maintaining the original shape. At this time, the cerium oxide contained in the film is spherical, and the cross section of the film can be exposed by, for example, processing by a focused ion beam (FIB), and it can be confirmed by observation by a transmission electron microscope (TEM).

In addition, the adhesion amount (hereinafter also referred to as "Si adhesion amount") in terms of Si (germanium element) of cerium oxide on each side of the plated steel sheet is 1 to 40 mg/m ² . When the Si adhesion amount is within the above range, the resin adhesion is excellent. Further, the Si adhesion amount is preferably from 1 to 25 mg/m ² for the reason that the cost performance is excellent.

When the Si adhesion amount is less than 1 mg/m ² , the resin adhesion is poor. Further, when the Si adhesion amount exceeds 40 mg/m ² , aggregation failure occurs in the film to lower the resin adhesion.

The Zr adhesion amount, the Ti adhesion amount, and the Si adhesion amount can be measured by surface analysis by fluorescent X-ray.

Further, the Zr in the film is used as, for example, zirconia, zirconium hydroxide, or fluorine. It is contained in a zirconium compound such as zirconium, zirconium phosphate or the like. The above-mentioned Zr adhesion amount means the Zr equivalent amount of the zirconium compounds.

Ti in the film is contained as a titanium compound such as titanium phosphate, hydrated titanium oxide, or a composite compound thereof. The above-mentioned Ti adhesion amount means the amount of Ti in terms of the titanium compound.

(best aspect of the film)

As for the preferred state of the film, the atomic ratio of Ti to Zr (Ti/Zr) in the outermost surface of the film (the outermost surface opposite to the side of the plated steel plate) is 0.05 to 2.0, and the atoms of Si and Zr are listed. The ratio (Si/Zr) is 0.1 to 3.0. In this case, the resin adhesion of the steel sheet for containers is more excellent.

The atomic ratio is determined by analyzing the peaks of Zr3d, Ti2p, and Si2p by XPS (X-ray Photoelectron Spectroscopy).

The XPS analysis is enumerated as, for example, the following conditions.

Device: AXIS-HS manufactured by Shimadzu / KRATOS

X-ray source: monochromatic AlKα ray (hv=1486.6eV)

Measurement area: Mixing mode 250 × 250 (μm)

[Method for Producing Steel Sheet for Container, Treatment Liquid]

The method for producing the steel sheet for a container of the present invention is not particularly limited, and it is preferred to include at least a plating steel sheet in a treatment liquid (hereinafter also referred to as "the treatment liquid of the present invention") to be described later, or by The plated steel sheet immersed in the treatment liquid of the present invention is subjected to cathodic electrolysis treatment, thereby forming the upper portion The method of forming a film of a film (hereinafter also referred to as "the method of producing the present invention").

Hereinafter, the production method of the present invention will be described, and in the same description, the treatment liquid of the present invention will be described.

<film formation step>

The film forming step is a step of forming the film on the surface of the plating layer side of the plated steel sheet, and immersing the plated steel sheet in the treatment liquid of the present invention to be described later (immersion treatment), or applying a cathode to the impregnated steel sheet. The step of electrolytic treatment. The cathodic electrolysis treatment is preferred because it can obtain a uniform film more quickly than the comparable impregnation treatment. Further, the electrolysis of the cathodic electrolysis treatment and the anodic electrolysis treatment may be performed alternately.

Hereinafter, the conditions of the treatment liquid and cathodic electrolysis treatment of the present invention to be used will be described in detail.

(treatment liquid of the present invention)

The treatment liquid of the present invention contains a Zr component (Zr compound) as a Zr supply source for supplying Zr (zirconium element) to the above film.

Examples of the Zr compound contained in the treatment liquid of the present invention include, for example, zirconium hexafluoride acid and/or a salt thereof (e.g., potassium or ammonium), zirconium oxyacetate, zirconium oxynitrate, and the like. Further, zirconium hexafluoride acid is also called zirconium hydrofluoric acid. Zirconium oxyacetate [ZrO(CH ₃ COO) ₂ ] is also known as zirconyl acetate. Zirconium oxynitrate [ZrO(NO ₃ ) ₂ ] is also known as zirconyl nitrate.

The content of the Zr compound in the treatment liquid of the present invention is preferably 0.3~10.0g/L, more preferably 0.5~4.0g/L.

The treatment liquid of the present invention contains a Ti component (Ti compound) as a Ti supply source for supplying Ti (titanium element) to the above film.

The Ti compound contained in the treatment liquid of the present invention is exemplified by, for example, titanium lactate, titanium hexafluoride and/or a salt thereof (e.g., potassium, ammonium, etc.), titanium alkoxide, titanium ammonium oxalate, titanium potassium oxalate dihydrate, sulfuric acid. Titanium, etc. Further, titanium lactate [Ti(OH) ₂ [OCH(CH ₃ )COOH] _{2 is} also called dihydroxybis(lactic acid) titanium, and its ammonium salt (monoammonium salt or diammonium salt) is also included in the present invention. In addition, titanium hexafluoride is also known as titanium hydrofluoric acid.

The content of the Ti compound in the treatment liquid of the present invention is preferably from 0.1 to 10 g/L, more preferably from 0.2 to 1.0 g/L.

The treatment liquid of the present invention further contains cerium oxide as a Si supply source for supplying Si (germanium element) to the film, but the cerium oxide preferably contains colloidal cerium oxide based on the cerium oxide contained in the film. .

Here, the colloidal cerium oxide is a dispersion system in which spherical cerium oxide having SiO ₂ as a basic unit is dispersed in a dispersion medium such as water. The amount of the dispersion medium is not particularly limited, but is usually, for example, 20 to 30% by mass based on the solid content of the colloidal cerium oxide.

The colloidal ceria used in the present invention preferably has an average particle diameter of 40 nm or less. When the average particle diameter of the colloidal cerium oxide is within this range, the specific surface area of the Si compound precipitated in the film is larger, and the resin adhesion is further improved.

On the other hand, there is no special limit on the average particle size of colloidal cerium oxide. Further, for example, it is preferably 5 nm or more in general circulation.

The average particle diameter can be measured by the BET method (converted from the specific surface area by the adsorption method). In addition, it can also be substituted by the average value measured by an electron microscope.

The content of the Si compound in the treatment liquid of the present invention is preferably from 0.01 to 5.0 g/L, more preferably from 0.1 to 4.0 g/L, in the case of colloidal cerium oxide.

Further, the treatment liquid of the present invention preferably contains a conductive auxiliary agent, specifically, an anion containing a nitrate ion, and at least one cation selected from the group consisting of potassium ions, ammonium ions and sodium ions as the above-mentioned conductive auxiliary agent. .

By including the above-mentioned conductive auxiliary agent in the treatment liquid of the present invention, the production line speed at which the above-mentioned film can be formed can be increased. That is, high speed operability is excellent. This is considered to be reduced by the inclusion of conductive additives. It is easy to improve the conductivity of the treatment liquid, that is, the liquid resistance, and it is easy to apply a high current with high speed.

The conductive auxiliary agent is substantially contained in the treatment liquid of the present invention as a salt (for example, ammonium nitrate, potassium nitrate, sodium nitrate or the like) in which the anion and the cation are ion-bonded, and the content thereof is based on high-speed workability. The reason for being more excellent is preferably from 0.1 to 10.0 g/L, more preferably from 0.5 to 5.0 g/L.

Further, as the solvent in the treatment liquid of the present invention, water is usually used, but an organic solvent may be used in combination.

The pH of the treatment liquid of the present invention is not particularly limited, and is preferably pH 2.0 to 5.0. If it is in this range, the processing time can be shortened, and the stability of the treatment liquid is excellent.

The pH can be adjusted using conventional acid components (eg, phosphoric acid, sulfuric acid). An alkali component (for example, sodium hydroxide or ammonia).

The treatment liquid of the present invention may optionally contain a surfactant such as sodium lauryl sulfate or acetylene glycol. Further, the treatment liquid may contain a condensed phosphate such as pyrophosphate based on the stability of the adhesion behavior over time.

Return to the description of the film formation step again. In the film formation step, the liquid temperature of the treatment liquid at the time of the treatment is more excellent in the formation efficiency of the film and the uniformity of the structure, and is preferably 20 to 80 ° C, more preferably 40 to 60 ° C.

In the film formation step, the electrolytic current density at the time of performing the cathodic electrolysis treatment is preferably a low current density, more specifically, 0.05 to 7.0, for the reason that the resin adhesion and corrosion resistance of the film are more excellent. A/dm ^{2 is} preferably 1.0 to 4.0 A/dm ² . By using the treatment liquid of the present invention, a film can be formed at a low current density.

In this case, the energization time of the cathodic electrolysis treatment is preferably 0.1 to 5 seconds, more preferably 0.3 to 2 seconds, from the viewpoint of suppressing the decrease in the adhesion amount to form a stable film and further suppressing the deterioration of the characteristics of the formed film. .

Further, the electric density at the time of cathodic electrolysis treatment is preferably from 0.20 to 15 C/dm ² , more preferably from 0.40 to 10 C/dm ² .

After the cathodic electrolysis treatment or the like, in order to remove the unreacted material, the obtained steel sheet may be subjected to a water washing treatment and/or drying. The temperature and the manner of drying are not particularly limited, and for example, a general-purpose dryer or an electric furnace drying method can be applied.

The temperature at the time of drying treatment is preferably 100 ° C or less. The lower limit is not particularly limited, but is usually about room temperature.

The steel sheet for containers of the present invention obtained by the production method of the present invention is used for the production of various containers such as DI cans, food cans, and beverage cans.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples. However, the invention is not limited to the embodiments.

<Manufacture of plated steel sheets>

A plated steel sheet was produced by the following two methods [(K-1) and (K-2)].

(K-1)

The steel plate (T4 original plate) having a thickness of 0.22 mm was subjected to electrolytic degreasing and pickling, followed by Sn plating. Next, heat-melting treatment is applied to a temperature equal to or higher than the melting point of tin, and a plating layer of Sn adhesion amount on each side shown in the second table is formed on both surfaces of the T4 original plate. Thereby, a plating layer made of an Fe-Sn alloy layer/Sn layer is sequentially formed from the lower layer side.

(K-2)

The steel plate (T4 original plate) having a thickness of 0.22 mm was subjected to electrolytic degreasing, and a nickel plating layer was formed on both surfaces using a Watts bath with a Ni adhesion amount on each side shown in Table 2, at 10 vol.%. In a H ₂ +90 vol.% N ₂ atmosphere, the nickel plating was diffused and permeated at 700 ° C to form a Ni-Fe alloy layer (Ni-containing layer) on both surfaces (the Ni adhesion amount is shown in Table 2).

Next, using a Sn plating bath, the amount of Sn attached to each side shown in the second table is formed on both sides of the steel sheet having the Ni layer on the surface layer. After the Sn layer, a heat-melting treatment is applied at a temperature higher than the melting point of Sn to form a plating layer on both surfaces of the T4 original plate. According to this, a plating layer made of a Ni—Fe alloy layer/Fe—Sn—Ni alloy layer/Sn layer is sequentially formed from the lower layer side.

Use the treatment liquid (solvent: water) of the composition shown in Table 1 to The bath temperature and electrolysis conditions (current density, energization time) shown in Table 2 were subjected to cathodic electrolysis treatment on the steel sheet. Subsequently, the obtained steel sheet was washed with water, and dried at room temperature using a blower to form a film on both sides.

In addition, the colloidal cerium oxide shown in Table 1 is used in Nissan. SNOWTEX OXS (average particle size: 6 nm), SNOWTEX OS (average particle size: 10 nm), SNOWTEX O (average particle size: 15 nm), SNOWTEX O-40 (average particle size: 25 nm), SNOWTEX OL (manufactured by Chemical Industry Co., Ltd.) Average particle size: 45 nm).

Further, the orthophosphoric acid shown in the first table is a phosphoric acid concentration of 85% by mass.

The resin sheets produced were evaluated for resin adhesion and corrosion resistance by the following methods. The amount of each component and the evaluation results are shown in Table 2.

Further, the Ti adhesion amount, the Zr adhesion amount, the Si adhesion amount, and the atomic ratio of the film were measured by the above method.

<Resin Adhesion>

A film of a terephthalic acid copolymerized polyethylene terephthalate having a thickness of 25 μm and a copolymerization ratio of 12 mol% was laminated on both surfaces of the produced steel sheet for containers to prepare a laminated steel sheet. The laminate is heated by a pair of rubber rollers The steel sheet and the film of 210 ° C were used to melt the film on the steel sheet, and after passing through a rubber roller, water cooling was performed within 1 second. At this time, the feeding speed of the steel sheet was 40 m/min, and the nip length of the rubber roller was 17 mm. Here, the nip length is the length of the conveying direction of the portion where the rubber roller contacts the steel sheet. Next, the following laminated resin sheets were subjected to the following resin adhesion evaluation.

The evaluation of the resin adhesion was carried out by a 180-degree peeling test in a cooking environment at a temperature of 150 ° C and a relative humidity of 100%. The 180-degree peeling test is shown in Fig. 1(a), and a test piece (size: 30 mm × 100 mm) in which a portion 3 of the steel sheet 1 is cut out using the film 2 is left, as shown in Fig. 1 (b), in the test piece. One end of the weight 4 (150 g) was folded back to the side of the film 2 at 180 degrees, and the film peeling test was carried out for 30 minutes. Next, the peeling length 5 shown in FIG. 1(c) was measured, and the resin adhesiveness was evaluated as follows. When it was ◎ or ○, the resin adhesiveness was favorable.

◎: peeling length is less than 40mm

○: The peeling length is 40 mm or more and less than 50 mm.

△: peeling length is 50 mm or more and less than 70 mm

×: peeling length of 70 mm or more

<Corrosion resistance>

The epoxy phenol-based coating material was applied to both surfaces of the steel sheet for containers to be coated so as to have an adhesion amount of 50 mg/dm ² , and then baked at 210 ° C for 10 minutes to form a coating film. Then, it was immersed in a beaker of a commercially available tomato juice at 50 ° C for 10 days, and the coating film was visually observed for peeling and rust, and evaluated as follows. If it was ○, the corrosion resistance was good.

○: The coating film was not peeled off and was not rusted (same as the chromate treated material)

△: The coating film was not peeled off and slightly rusted.

×: The film peeled off and rusted significantly.

From the results shown in the above Tables 1 to 2, it is understood that the examples of the present invention are excellent in resin adhesion and corrosion resistance.

On the other hand, in Comparative Examples 1, 2, 8, and 9 in which the amount of Zr adhesion was less than 1 mg/m ² , the resin adhesion and the corrosion resistance were inferior.

Further, in Comparative Examples 3, 4, 10 and 11 in which the Ti adhesion amount was 0.5 mg/m ² or less, the resin adhesion was inferior.

Further, in Comparative Examples 5 to 7 and 12 to 14 in which the Si adhesion amount was less than 1 mg/m ² or more than 40 mg/m ² , the resin adhesion was inferior.

Claims (5)

A steel sheet for a container, comprising: a plated steel sheet containing a plating layer covering at least a part of a surface of the steel sheet; and a steel sheet for a container disposed on a surface of the plated steel sheet on a surface of the plating layer. The coating film contains Zr, Ti, and cerium oxide, and the Zr conversion amount of each surface of the plated steel sheet of the film is 1 to 40 mg/m ² , and the Ti conversion amount per side of the plated steel sheet exceeds 0.5. Mg/m ² and less than 10 mg/m ² , and the Si conversion amount per side of the plated steel sheet is 1 to 40 mg/m ² . The steel sheet for containers according to claim 1, wherein each of the surfaces of the plated steel sheets of the film has a Ti conversion amount of more than 3 mg/m ² and less than 10 mg/m ² . The steel sheet for a container according to claim 1 or 2, wherein an atomic ratio (Ti/Zr) of Ti to Zr on the outermost surface of the film opposite to the side of the plated steel sheet is 0.05 to 2.0, and an atomic ratio of Si to Zr (Si) /Zr) is 0.1~3.0. The steel sheet for containers according to claim 1 or 2, wherein the plating layer further contains at least one layer selected from the group consisting of a Ni layer, a Ni-Fe alloy layer, an Fe-Sn alloy layer, and an Fe-Sn-Ni alloy layer. The steel sheet for containers according to claim 3, wherein the plating layer further contains at least one layer selected from the group consisting of a Ni layer, a Ni-Fe alloy layer, an Fe-Sn alloy layer, and an Fe-Sn-Ni alloy layer.