KR101784767B1 - Steel sheet for containers - Google Patents

Abstract

It is an object of the present invention to provide a steel sheet for a container exhibiting excellent appearance characteristics and excellent paint adhesion and anti-yellowing resistance after high temperature retort treatment without containing Cr in the coating film. A steel sheet for a container according to the present invention is a steel sheet for a container having a tin-plated layer-bearing steel sheet having a tin plating layer covering at least a part of the surface of the steel sheet and the steel sheet and a coating film disposed on a surface of the tin- Wherein the coating film contains tin oxide, Zr, Ti and P, the amount of electricity required for reduction of tin oxide is 0.20 to 3.50 mC / cm2, the amount of metal zirconium in the coating is 1.0 to 40.0 mg / m2, / M < 2 > and less than 2.50 mg / m < 2 >

Description

{STEEL SHEET FOR CONTAINERS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate for containers used in DI can (iron cans), food cans, beverage cans and the like, and more particularly to a steel plate for containers coated with a treatment liquid containing no Cr.

As the steel sheet for containers (surface-treated steel sheet for can), a tin-plated steel sheet which is conventionally called a "tin plate" is widely used. In such a tin-plated steel sheet, a chromate film is usually formed on the tin plating surface by immersing the steel sheet in an aqueous solution containing a hexavalent chromium compound such as dichromic acid, or by performing an electrolytic treatment in this solution.

By the formation of the chromate film, oxidation of the tin plating surface, which is liable to occur during long-term storage, is prevented, and deterioration of appearance (yellow discoloration) is suppressed. Further, when the steel sheet is coated and used, cohesion failure due to the growth of the oxide film of tin (Sn) is prevented, and adhesion between the organic resin such as paint and steel sheet (hereinafter simply referred to as coating adhesion) can be ensured.

On the other hand, on the basis of current environmental problems, the movement to regulate the use of Cr is proceeding in various fields, and some steel processing techniques for replacing chromate treatment are also proposed for steel sheets for containers.

For example, Patent Document 1 discloses a steel sheet for a container having a base Ni layer, a Sn plating layer, a conversion treatment layer containing tin oxide and tin phosphate, and a Zr-containing coating layer on the surface of a steel sheet .

Patent Document 2 discloses a surface treatment layer comprising at least one surface treatment layer containing at least one of Sn, Ni, Fe, Cr, and hydrated Cr oxide on the surface of a steel sheet, a Ti- or Zr- And an organic resin including an organic silicon compound are disclosed.

JP-A-2009-249691 Japanese Patent Application Laid-Open No. 2000-234181

On the other hand, in recent years, as the demand for aesthetics of consumers has increased, it is required to further improve the characteristics (appearance characteristics, paint adhesion and resistance to yellowing and blackening) required for steel sheets for containers. In particular, good retention of the paint after retorting at a high temperature, such as a retort temperature of 140 캜, and resistance to blackening of the yellowing are required.

The inventors of the present invention evaluated the characteristics of a conventional steel sheet for a container having a tin plating layer, including the steel sheet for a container having the tin plating layer described in Patent Documents 1 and 2. As a result, the steel sheet for these containers exhibited excellent appearance, It was not possible to meet the level required in recent years in any of the yellowing and blackening, and further improvement was required.

In view of the above circumstances, it is an object of the present invention to provide a steel sheet for a container exhibiting excellent appearance characteristics, excellent paint adhesion and excellent resistance to paint adhesion after high temperature retort treatment without containing Cr in the film.

Means for Solving the Problems The present inventors have intensively studied in order to achieve the above object and as a result have found that by forming a coating film containing a predetermined amount of tin oxide and a predetermined amount of Zr, Ti and P on a tin- Is obtained.

That is, the inventors of the present invention have found that the above problems are solved by the following constitutions.

(1) A steel sheet for a container having a tin-plated layer steel plate having a steel plate and a tin plating layer covering at least a part of the surface of the steel plate, and a coating film disposed on the tin-plated layer side of the tin-

Wherein the coating contains tin oxide and Zr, Ti and P,

The electricity quantity required for reduction of the tin oxide is 0.20 to 3.50 mC /

Wherein the metal zirconium content in the coating is 1.0 to 40.0 mg / m 2, the amount of metal titanium is more than 0.01 mg / m 2 and less than 2.50 mg / m 2, and the phosphorus amount is 0.10 to 10.00 mg / m 2.

(2) the atomic ratio (Ti / Zr) between Ti and Zr on the outermost surface of the film opposite to the steel sheet side is 0.1 to 0.4 and the atomic ratio (P / Zr) 1.4. The steel sheet for containers according to (1).

(3) the phosphorus present in the region from the outermost surface of the coating to the intermediate portion of the depth corresponding to 1/2 of the total thickness is 70% or more of the total phosphorus content in the coating, (2).

(4) The steel sheet for a container according to any one of (1) to (3), wherein the tin-plated layer-coated steel sheet is formed by using a steel sheet having a nickel-containing layer on its surface.

(5) A steel sheet having a tin plating layer having a steel sheet and a tin plating layer covering at least a part of the surface of the steel sheet is immersed in a treatment solution containing Zr ions, Ti ions and phosphorus ions, or an electrolytic treatment is applied to the treatment solution A steel sheet having a tin plating layer having a steel sheet and a tin plating layer covering at least a part of the surface of the steel sheet and a coating disposed on the tin plating layer side of the steel sheet with the tin plating layer,

Wherein the coating contains tin oxide and Zr, Ti and P,

The electricity quantity required for reduction of the tin oxide is 0.20 to 3.50 mC /

The amount of metal zirconium in the coating is 1.0 to 40.0 mg / m 2, the amount of metal titanium is more than 0.01 mg / m 2 and less than 2.50 mg / m 2, and the phosphorus content is 0.10 to 10.00 mg /

Wherein zirconium oxyacetate or zirconium acetate is used as a source of the Zr ions.

(6) The steel sheet for containers according to (2), wherein the coating film is formed by a negative electrode electrolytic treatment, and the negative electrode electrolytic treatment has an electric charge density of 0.40 to 1.50 C / dm 2.

According to the present invention, it is possible to provide a steel sheet for a container exhibiting excellent appearance characteristics, excellent paint adhesion and excellent resistance to paint after high-temperature retort treatment without containing Cr in the film.

(Mode for carrying out the invention)

Hereinafter, preferred embodiments of the steel sheet for a container of the present invention will be described in detail.

First of all, the characteristic feature of the present invention is that a coating film containing a predetermined amount of tin oxide and a predetermined amount of Zr, Ti, and P is provided on a tin-plated steel sheet (tin-plated steel sheet) . In the present embodiment, Cr is not used, and excellent appearance characteristics are obtained, and the paint adhesion and the sulphurization resistance after hot retort are also excellent. In particular, it has been found that by adding a predetermined amount of Ti to the film, an excellent effect can be obtained even after the film is subjected to a high-temperature retort environment.

That is, by containing a predetermined amount of tin oxide, a predetermined amount of Zr, and a trace amount of Ti in a coating containing a predetermined amount of P, it is possible to obtain good coating adhesion after hot retorting, It is possible to give.

Further, when a fluorine-free compound (zirconium compound) such as zirconium oxyacetate or zirconium acetate is used for the treatment liquid, the precipitation coating has a higher level of adhesion, and the same coating adhesion after hot retorting as above, It has very excellent performance in terms of performance.

The mechanism by which the effect of the present invention is obtained is still presumed, but the Ti compound precipitated in the film has a large ratio surface area and needle shape, and the anchor effect of the compound causes the coating film and the coating film The diffusion of moisture at a high temperature at the interface between the coating film and the coating film is suppressed and the effect of the present invention is synergistically improved by forming a complex compound with Zr in the coating film.

Further, it has been found that a coating film having a predetermined deposition amount of Zr, Ti and P can be efficiently obtained by performing the negative electrode electrolytic treatment at a low electric charge density when obtaining such a coating film.

Particularly, in the case of depositing a film from a negative electrode electrolytic solution, it is possible to suppress film discoloration even in a retort treatment at 140 ° C for 3 hours, which is a more severe condition in the resistance to sulphurization when the electron quantity density is 0.40 to 1.50 C / have.

The steel sheet for a container of the present invention has a tin-plated layer-coated steel sheet and a coating disposed on the tin-plated layer side of the tin-plated layer-coated steel sheet.

Hereinafter, concrete embodiments of the tin-plated layer-coated steel sheet and the coating film will be described in detail. First, an embodiment of a tin-plated layer-coated steel sheet will be described in detail.

<Steel plate with tin-plated layer>

The tin-plated layer-coated steel sheet has a steel sheet and a tin plating layer covering at least a part of the surface of the steel sheet. Hereinafter, embodiments of the steel sheet and the tin plating layer will be described in detail.

(Steel plate)

The kind of the steel sheet in the tin-plated steel sheet is not particularly limited, and a steel sheet (for example, a low carbon steel sheet, a very low carbon steel sheet) used as a container material can be used. The manufacturing method and material of the steel sheet are not particularly restricted, and they are manufactured through a process such as hot rolling, acid cleaning, cold rolling, annealing, temper rolling,

The steel sheet may be prepared by forming a nickel (Ni) -containing layer on its surface, if necessary, and forming a tin plating layer on the Ni-containing layer. By performing tin plating using a steel sheet having a Ni-containing layer, a tin plating layer containing island-like Sn can be formed, and the weldability is improved.

The Ni-containing layer may contain nickel, and examples thereof include a Ni-plated layer and a Ni-Fe alloy layer.

The method of applying the Ni-containing layer to the steel sheet is not particularly limited, and for example, a known method such as electroplating may be used. When the Ni-Fe alloy layer is provided as the Ni-containing layer, the Ni-Fe alloy layer can be formed by aligning the Ni diffusion layer by applying Ni to the surface of the steel sheet by electroplating or the like and then annealing.

The amount of Ni in the Ni-containing layer is not particularly limited, and is preferably 50 to 2000 mg / m &lt; 2 &gt; Within this range, it is more excellent in the resistance to sulphurization and is advantageous in terms of cost.

(Tin plating layer)

The tin-plated layer-coated steel sheet has a tin plating layer on the surface of the steel sheet. The tin plating layer may be formed on at least one surface of the steel sheet or may be formed on both surfaces.

The Sn adhesion amount per one side of the steel sheet in the tin plating layer is preferably 0.1 to 15.0 g / m 2. When the amount of Sn deposited is within the above range, the steel sheet for containers has excellent appearance and corrosion resistance. Among them, from the viewpoint of better properties, it is preferably 0.2 to 15.0 g / m 2, and more preferably 1.0 to 15.0 g / m 2 from the viewpoint of better processability.

The amount of Sn deposited can be measured by surface analysis by coulometric method or fluorescent X-ray. In the case of fluorescent X-ray, the amount of Sn of the metal Sn amount is used to specify the amount of metal Sn, and the amount of metal Sn is specified using the same calibration curve.

The tin plating layer is a layer covering at least a part of the surface of the steel sheet, and may be a continuous layer or a discontinuous islands shape.

As the tin plating layer, tin is heated and melted by a tin plating layer obtained by plating tin or by a re-flow treatment in which tin plating is performed and then electrification heating is performed to form a tin plating layer on the tin plating bottom layer (tin plating / But also a tin plating layer in which a Sn alloy layer is partially formed.

As the tin plating layer, tin plating is performed on a steel sheet having a Ni-containing layer on its surface, and the tin is heated and melted by reflow treatment or the like for further energizing heating to form a tin plating bottom layer (tin plating / A Fe-Sn-Ni alloy, an Fe-Sn alloy layer, and the like.

As a method of producing the tin plating layer, a well-known method (for example, an electroplating method or a method of dipping in molten Sn and plating) can be mentioned.

(For example, 2.8 g / m &lt; 2 &gt;) by using a phenol sulfonate tin plating bath, a methane sulfonate tin plating bath or a halogen tin plating bath, After the plating, the reflow treatment is performed at a temperature higher than the melting point (231.9 DEG C) of Sn to form a tin plating layer in which an Fe-Sn alloy layer is formed on the lowest layer of the tin alone plating layer. In the case where the reflow process is omitted, a plating layer of a tin base can be produced.

When the steel sheet has a Ni-containing layer on the surface thereof, a tin plating layer is formed on the Ni-containing layer and the reflow treatment is performed to form a Fe-Sn-Ni alloy layer on the lowest layer (tin plating / steel sheet interface) Layer, an Fe-Sn alloy layer, and the like are formed.

<Coating>

The coating film is disposed on the surface of the above-mentioned tin-plated layer-coated steel sheet on the tin plating layer side.

The coating contains tin oxide and Zr, Ti and P as its components. First, each component will be described in detail below, and then the method for forming the coating film will be described in detail.

(Tin oxide)

The coating contains tin oxide, and the content thereof is 0.20 to 3.50 mC / cm &lt; 2 &gt; Within this range, the yellowing and blackening resistance is excellent. Further, the electricity quantity is preferably 0.30 mC / cm &lt; 2 &gt; or more, and more preferably 0.70 to 1.80 mC / cm &lt; 2 &gt;

When the amount of electricity required for reduction of tin oxide is less than 0.20 mC / cm &lt; 2 &gt; and exceeds 3.50 mC / cm &lt; 2 &gt;, appearance characteristics of the steel sheet for containers, paint adhesion,

The amount of electricity required for the reduction of the tin oxide was measured by means of a bubbling or the like of nitrogen gas in a vessel of the present invention at a constant current of 0.05 mA / cm 2 in a 0.001 mol / L aqueous solution of hydrobromic acid, The steel sheet for use can be obtained from a potential-time curve obtained by cathodic electrolysis.

(Zr, Ti and P)

The coating contains Zr (zirconium), Ti (titanium) and P (phosphorus).

More specifically, the coating contains Zr (zirconium element), and the amount of the metal zirconium (amount of metal Zr in the coating) is 1.0 to 40.0 g / m 2. When the amount of the metal zirconium is within the above range, the steel sheet for a container is excellent in appearance characteristics, paint adhesion, and blacking resistance to blackening. Among them, the amount of metal zirconium is preferably 2.5 to 40 mg / m 2, more preferably 2.5 to 18.0 mg / m 2, and still more preferably 4.0 to 12.0 mg / m 2, from the viewpoint of better resistance to sulfidization.

In addition, when the amount of metal zirconium is less than 1.0 mg / m 2 or more than 40.0 mg / m 2, the paint adhesion, the yellowing and blackening resistance, or the appearance characteristics are inferior.

The film contains Ti (titanium element), and the amount of the metal titanium (amount of the metal Ti in the film) is more than 0.01 mg / m2 and less than 2.50 mg / m2. When the amount of the metal titanium is within the above range, it is excellent in paint adhesion and resistance to sulphide blackening. The Ti adhesion amount is preferably 1.50 mg / m 2 or less, more preferably less than 1.00 mg / m 2, and even more preferably 0.05 to 0.90 mg / m 2 from the viewpoint of better appearance characteristics.

Further, when the amount of the metal titanium is 0.01 mg / m 2 or less, the paint adhesion or the yellowing black discoloration is poor. When the amount of titanium metal is 2.50 mg / m &lt; 2 &gt; or more, the appearance is an interference color, and appearance characteristics are poor, or sulfhydryl blackening is poor.

The coating contains P (phosphorus element), and its phosphorus (P amount in the coating) is 0.10 to 10.00 mg / m 2. P is necessary for maintaining the paint adhesion. When the phosphorus content is within the above range, the steel sheet for a container has excellent appearance characteristics, paint adhesion, and resistance to sulphurous blackening. Among them, the phosphorus content is preferably 1.00 to 10.00 mg / m &lt; 2 &gt;, and more preferably 1.00 to 5.00 mg / m &lt; 2 &gt;

Further, when the phosphorus content is less than 0.10 mg / m &lt; 2 &gt; and more than 10.00 mg / m &lt; 2 &gt;

The amount of the metallic zirconium, the amount of the metallic titanium, and the phosphorus content can be measured by surface analysis by fluorescent X-ray.

The Zr in the coating film is included, for example, as a zirconium compound such as zirconium oxide, zirconium hydroxide, zirconium fluoride, zirconium phosphate, or a complex compound thereof. The metal zirconium amount means a Zr-converted amount of the zirconium compound.

The Ti in the film is included, for example, as a titanium compound such as titanium phosphate, titanium hydroxides, or complex compounds thereof. The amount of the metallic titanium means the equivalent amount of Ti of the titanium compound.

The P in the coating film is included, for example, as a phosphate compound such as iron phosphate, nickel phosphate, tin phosphate, zirconium phosphate, or a complex compound thereof formed by reaction with a base (steel plate, tin plating layer).

(Suitable embodiment of coating)

(Ti / Zr) between Ti and Zr at the outermost surface (the outermost surface opposite to the steel sheet) of the coating is 0.1 to 0.4, and the atomic ratio of P to Zr (P / Zr) is 0.7 to 1.4. With this embodiment, the paint adhesion and the sulfur blacking resistance of the steel sheet for containers are more excellent.

The atomic ratio is obtained by analyzing peaks of Zr3d, Ti3d and P2p by XPS analysis.

As the XPS analysis, for example, the following conditions may be mentioned.

Device: AXIS-HS manufactured by Shimadzu Corporation / KRATOS

X-ray source: black and white AlK ray (hv = 1486.6 eV)

Measurement area: Hybrid mode 250 × 500 (㎛)

In another preferred embodiment of the film, a phosphorus amount (P amount) existing in a region from the outermost surface of the film (the outermost surface opposite to the steel sheet) to the middle portion of the depth corresponding to one- ) Is 70% or more of the total phosphorus (P amount present in the region up to the depth equivalent to the total thickness). Further, it is preferably not less than 80%, and the upper limit is not particularly limited and may be 100%.

In the above embodiment, the network structure of the phosphoric acid component is located near the outermost surface of the coating, so that the barrier property can be improved, the diffusion of the sulfide can be further suppressed, and the resistance to sulfur black is better.

As a specific method of the intermediate portion, for example, when the XRP analysis is carried out, at the position where the Zr intensity is first recognized (Ar sputtering start position (time)), to the position (time) where the Zr intensity disappears by Ar sputtering Is a region up to a depth corresponding to the total thickness of the coating film, and the point of time of 1/2 of the sputtering time corresponds to the middle portion of the coating film.

As the XPS analysis, for example, the following conditions may be mentioned.

Device: AXIS-HS manufactured by Shimadzu Corporation / KRATOS

X-ray source: black and white AlK ray (hv = 1486.6 eV)

Measurement area: Hybrid mode 250 × 500 (㎛)

(Method of forming film)

The above-mentioned method of forming the film is not particularly limited as long as it can form a coating film containing a predetermined amount of tin oxide and a predetermined amount of Zr, Ti and P. However, there is a problem in that a negative electrode electrolytic treatment is performed on a tin-plated layer-coated steel sheet in that the coating film exhibiting a desired effect can be produced with high productivity; and a step (1) And a step (2) of immersing the steel sheet in the treatment liquid or performing a negative electrode electrolytic treatment on the immersed steel sheet.

Hereinafter, the steps (1) and (2) will be described in detail.

(Step (1))

Step (1) is a step of performing a negative electrode electrolytic treatment on a tin-plated layer-coated steel sheet in an alkaline aqueous solution (particularly, an aqueous solution of sodium carbonate).

Normally, the surface of the tin plating layer is oxidized to form tin oxide during the production of the tin plating layer. By subjecting the steel sheet to a negative electrode electrolytic treatment, unnecessary tin oxide can be removed and the amount of tin oxide can be adjusted.

As will be described later, tin oxide is formed even when a steel sheet is treated with a treatment solution containing Ti ions, Zr ions, and phosphoric ions. However, the amount of tin oxide after removal of tin oxide The tin oxide showing the electric quantity required for the desired reduction can be obtained.

Examples of the solution used in the negative electrode electrolytic treatment include an alkaline aqueous solution (for example, an aqueous solution of sodium carbonate).

The concentration of the alkaline component (for example, sodium carbonate) in the alkaline aqueous solution is not particularly limited, but is preferably 5 to 15 g / L, more preferably 8 to 12 g / L in view of more efficient removal of tin oxide desirable.

The temperature of solution of the alkaline aqueous solution during the negative electrode electrolysis treatment is not particularly limited, but is preferably 40 to 60 占 폚, because it is more excellent in appearance characteristics.

The electrolytic conditions (current density, electrolysis time) of the negative electrode electrolytic treatment are appropriately adjusted so as to obtain tin oxide showing the electric quantity required for the above-mentioned desired reduction.

After the negative electrode electrolytic treatment, a water washing treatment may be carried out if necessary.

(Step (2))

Step (2) is a step of forming a film containing a predetermined amount of Zr, Ti, and P. This is a step of immersing (immersing) the steel sheet into a treatment solution containing Ti ions, Zr ions, and phosphate ions, or performing a negative electrode electrolytic treatment on the immersed steel sheet. The negative electrode electrolytic treatment is preferable for the reason that a uniform film can be obtained at a higher speed than the immersion treatment. Alternatively, alternating electrolysis may be alternately performed in which cathodic electrolytic treatment and anodic electrolytic treatment are alternately performed.

The treatment liquid to be used, the conditions of the negative electrode electrolytic treatment, and the like are described in detail below.

Examples of the treatment liquid to be used include a solution containing Zr ions, Ti ions, and phosphate ions.

Examples of the source of the Zr ion include Zr element, and examples thereof include Zr ammonium carbonate, Zr potassium carbonate, Zr sulfuric acid, Zr nitrate, zirconium oxyacetate, zirconium acetate ((CH ₃ COO) nZr, n = 2) Zr compounds that do not contain fluorine atoms of fluorine atoms and fluorozirconic acid include ammonium hexafluoroarsenate, ammonium zirconium hexafluoride, potassium zirconium hexafluoride, and hydrofluoric acid zirconium fluoride.

As the source of the Ti ions, it is sufficient to contain a Ti element, and examples thereof include titanium fluoride acid, ammonium titanium fluoride, potassium titanyl fluoride, potassium titanate, calcium titanate and the like.

As the source of the phosphate ions, any phosphorus element may be contained, and examples thereof include orthophosphoric acid, sodium phosphate, sodium hydrogen phosphate, monobasic aluminum phosphate, magnesium phosphate monobasic, calcium monobasic and the like.

The concentration of each ion in the treatment liquid is not particularly limited as long as a desired coating amount can be obtained. Among them, the Zr ion concentration in the treatment liquid is preferably from 0.30 to 5.0 g / l, the Ti ion concentration is preferably from 0.001 to 2 g / l, and the phosphoric acid (PO ₄ ^3- ) Ion concentration is preferably 0.01 to 5.0 g / l.

As the solvent in the treatment liquid, usually water is used, but organic solvents may be used in combination.

The pH of the treatment liquid may be suitably controlled from the precipitation efficiency of Zr, Ti and P, and is not particularly limited, but is preferably 2.0 to 5.0. Within this range, the treatment time can be shortened and the stability of the treatment liquid is excellent.

For adjusting the pH, a known acid component (for example, phosphoric acid, sulfuric acid) and an alkali component (for example, sodium hydroxide and ammonia water) may be used.

The treatment liquid may contain a surfactant such as sodium lauryl sulfate or acetylene glycol, if necessary.

From the standpoint of stability over time of the adhesion behavior, the treatment liquid may contain a condensed phosphate such as a pyrophosphate.

The liquid temperature of the treatment liquid at the time of the treatment is preferably 20 to 80 占 폚, more preferably 40 to 60 占 폚, from the viewpoints of the formation efficiency of the coating film and the uniformity of the structure, .

The electrolytic current density at the time of performing the negative electrode electrolytic treatment is preferably low current density in view of better appearance and resistance to blackening and blackening, more specifically, preferably from 0.05 to 7 A / dm 2, And more preferably 0.5 to 5 A / dm 2.

Further, the energization time of the negative electrode electrolytic treatment is preferably 0.1 to 5 seconds, more preferably 0.3 to 2 seconds, more preferably 0.1 to 5 seconds, in view of further suppressing the deposition amount and stably forming the coating film, desirable.

The electric-charge density at the time of the negative electrode electrolysis treatment is preferably from 0.20 to 3.50 C / dm 2, more preferably from 0.40 to 2.00 C / dm 2, from the viewpoint of better appearance.

Further, in order to cope with the more severe reticulatization time of more than 3 hours, a retort time of 3 hours or more is required to contain a predetermined amount of tin oxide and a predetermined amount of Zr, Ti and P, (Ti / Zr) and the atomic ratio (P / Zr) between P and Zr, and the electric quantity density is preferably 0.40 to 1.50 C / dm 2.

Further, after the negative electrode electrolytic treatment, if necessary, the obtained steel sheet may be subjected to water washing treatment and / or drying to remove unreacted materials. The temperature and method of drying are not particularly limited, and for example, a conventional dryer or an electric furnace drying method can be applied.

The temperature for the drying treatment is preferably 100 占 폚 or less. Within this range, oxidation of the coating can be suppressed, and the stability of the coating composition can be maintained. The lower limit is not particularly limited, but is usually about room temperature.

The steel sheet for containers obtained by the above treatment is used for the production of various containers such as DI can, cans, and beverage cans.

Example

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

&Lt; Preparation of steel sheet with tin-plated layer &

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

(K-1)

A steel sheet (T4 original plate) having a plate thickness of 0.22 mm was subjected to electrolytic degreasing and pickling, followed by tin plating with a Sn adhering amount per side surface shown in Table 3. [ Subsequently, a reflow treatment was performed at a temperature not lower than the melting point of Sn to form a Fe-Sn alloy layer and an Sn layer thereon to prepare a steel sheet with a tin-plated layer.

(K-2)

After the nickel plated layer formed by using the degreasing electrolyte to the steel sheet (T4 original plate) having a thickness of 0.22㎜ and Watt bath (watts bath) with one surface per Ni coating weight shown in Table _{3, 10vol.% H 2 +} 90vol.% N 2 atmosphere (Ni-containing layer) (indicating the amount of Ni adhered in Table 3) was formed by annealing at 700 占 폚 to diffuse penetration of nickel plating.

Then, the steel sheet having the Ni-containing layer in the surface layer was tin-plated with a Sn adhering amount per side surface shown in Table 3 by using a tin plating bath. Thereafter, reflow processing was performed at a temperature not lower than the melting point of Sn to form a Fe-Ni-Sn alloy layer and a discontinuous Sn layer thereon to prepare a tin-plated layer-coated steel sheet.

<Formation of Coating>

Bath temperature A steel sheet with a tin plating layer was immersed in an aqueous solution of sodium carbonate of 10 g / L at 50 占 폚, and a negative electrode electrolytic treatment was carried out under the conditions shown in Table 2 (step (1)).

Thereafter, the obtained steel sheet was subjected to a cathodic electrolytic treatment (electrolytic treatment) in accordance with the bath temperature, electrolysis conditions (current density, electrification time, electricity quantity density) shown in Table 2 and using the treating solution (solvent: water) (Step (2)). Thereafter, the obtained steel sheet was water-filtered and dried at room temperature using a blower to form a coating film.

The steel sheet thus prepared was evaluated for appearance characteristics, paint adhesion, and blackening resistance to blackening in the following manner. The amounts of each component and the evaluation results are summarized in Table 3.

<Appearance characteristics>

The appearance of the steel sheet having the film immediately after the production was visually observed and evaluated according to the following criteria. &Quot; o &quot; or &quot; o &quot;, the appearance was good.

&Quot; &amp; cir &amp; &quot;: beautiful appearance with metallic luster is observed.

&Quot; O: &quot;: a slightly white appearance, but a beautiful appearance is observed.

&Quot; DELTA &quot;: a spangle pattern or a nonuniform precipitation pattern is thinly observed, and a slightly white appearance is observed.

&Quot; x &quot;: a sequin-shaped or non-uniform deposition pattern is clearly observed, and an uneven appearance is observed.

<Paint adhesion property>

An epoxy phenolic coating material was applied on the coating film of the steel sheet immediately after the production to have an adhesion amount of 50 mg / dm 2, and then baked at 210 캜 for 10 minutes. Then, the steel sheet was subjected to a retort treatment at 140 DEG C for 2 hours, and then cooled to room temperature.

Subsequently, the steel sheet having the two coatings subjected to the retort processing was laminated so that the coated surface faced each other with the nylon adhesive film sandwiched therebetween. The steel sheet was squeezed at a pressure of 2.94 × 10 ⁵ Pa, a temperature of 190 ° C., Lt; / RTI &gt; Thereafter, this was divided into 5 mm-wide test pieces, and the strength required for peeling off the test pieces by using a tensile tester and measuring them was measured. The measurement results were evaluated as follows. &Quot;&amp; cir &amp;&quot; or &quot;&quot; indicates good paint adhesion.

&Quot;? &Quot;: 19.6 N (2 kgf) or more

&Quot;? &Quot;: 3.92 N (0.4 kgf) or more and less than 19.6 N

?: 1.96 N (0.2 kgf) or more and less than 3.92 N

&Quot; x &quot;: less than 1.96 N (0.2 kgf)

&Lt; Sulfur Black Degeneration 1 &gt;

An epoxy phenolic coating material was applied on the coating film of the steel sheet having the coating immediately after the production so as to have an adhesion amount of 50 mg / dm 2, followed by baking at 210 캜 for 10 minutes.

Subsequently, Erichsen 5 mm extrusion was performed so that the object surface became convex, and the resultant was immersed in a 5 mass% Na ₂ S solution (pH = 7, adjusted with lactic acid) and subjected to a retort treatment at 140 캜 for 2 hours I did.

The presence or absence of discoloration of sulphide was visually evaluated according to the following criteria. Also, it was said to be good when it was "○" or "◎". In addition, when Erichen part was peeled from Cellotape (registered trademark), and when the paint was adhered to the tape side, it was judged that adhesion was poor.

(Determination of yellowing discoloration)

"◎": No discoloration of dark brown in both the processed part and the flat part.

&Quot; O: &quot; indicates a slightly brownish discoloration in the processed portion, but no discoloration of dark brown in the flat plate portion.

&Quot; DELTA &quot; indicates a discolored discoloration of both the processed portion and the flat portion.

&Quot; x &quot;: Significant dark brown discoloration is observed in both the processed portion and the flat portion.

(Tape peeling evaluation)

&Quot; o &quot;: When no paint is attached to the tape side

&Quot; x &quot;: When paint is attached to the tape side

&Lt; Sulfur Black Degeneration 2 &gt;

Sulfur discoloration was evaluated in accordance with the same procedure as in the above-described Sulfur Black Dye 1 except that the retort time was changed from 2 hours to 3 hours. The evaluation criteria are the same as those of the above-described sulfurized blackening-modified 1.

In the following Table 1, numerical values in parentheses indicate g / L of each component.

The "chromate" (chromate treatment) shown in Table 2 was carried out under the conditions shown in Table 2 using an aqueous solution of Na bichromate (30 g / L).

The amount (mg / m &lt; 2 &gt;) of the components in each layer in Table 3 was measured by using fluorescent X-rays (manufactured by Rigaku Corporation). The amount of Sn deposited and the amount of Ni deposited mean the deposition amount per one side of the steel sheet.

In Table 3, "Ti / Zr (atomic ratio)" and "P / Zr (atomic ratio)" indicate atomic ratios of Ti and Zr on the outermost surface (Ti / Zr) and the atomic ratio (P / Zr) between P and Zr. This ratio was measured using AXIS-HS manufactured by Shimadzu / KRATOS Co. under the conditions of a black and white AlK ray (hv = 1486.6 eV) and a measurement area: Hybrid mode 250 x 500 (탆) as an X-ray source and Zr3d, Ti3d, P2p. &Lt; / RTI &gt;

The &quot; P presence rate &quot; in Table 3 indicates the ratio of the phosphorus content in the region from the outermost surface of the film to the middle portion of the film to the middle portion of the film, (%). The "P existence ratio" was measured under the conditions of a monochrome AlK ray (hv = 1486.6 eV) and a measurement area: Hybrid mode 250 × 500 (㎛) as an X-ray source using AXIS-HS manufactured by Shimadzu / KRATOS. (Time) at which the Zr intensity is lost by the Ar sputter at a position where the Zr intensity is recognized for the first time (Ar sputter start position (time)) is set to a region up to a depth corresponding to the entire thickness of the film, Half of the time corresponds to the middle portion of the film. The ratio of the integrated value (P intensity) from the position where the Zr intensity is first recognized to the intermediate portion to the integrated value (P intensity) from the position where the Zr intensity is recognized to the disappearance position is referred to as &quot; P existence rate &quot; .

The "amount of tin oxide (mC / cm 2)" in Table 3 was obtained by carrying out a constant current cathode electrolysis at a rate of 0.05 mA / cm 2 to the steel sheet obtained in a 0.001 mol / L aqueous hydrobromic acid solution degassed by nitrogen bubbling , And from the obtained potential-time curve, the electricity amount required for reduction was obtained.

In Table 3, &quot; Sulfur Black Degenerated 1 (Sulfated Color Change) &quot; indicates the result of evaluation of the discoloration of the &quot; Sulfur Black Oxide 1 &quot;, and &quot; 1>, and "Sulfurized black-modified 2 (sulphurized discoloration)" represents the evaluation result of the discoloration of the <Sulfurized black-modified 2>.

As shown in Table 3, it was confirmed that the steel sheet for a container of the present invention was excellent in paint adhesion, blackening resistance, and appearance.

From Examples 7, 8, 9, 17 and 19, the atomic ratio (Ti / Zr) between Ti and Zr on the outermost surface of the film opposite to the steel sheet side, and the atomic ratio P / Zr) was within a predetermined range, it was confirmed that paint adhesion and sulfur black coloration were more excellent.

Furthermore, it was confirmed from Example 18 that when the presence ratio of P is equal to or greater than a predetermined value, the resistance to light yellowing is better.

It was also confirmed from Examples 10, 16 and 19 that the appearance characteristics were better when the amount of the metal titanium was small (particularly, less than 1.0 mg / m 2).

From Examples 20 and 21, it was also confirmed that when the amount of metal zirconium and the amount of phosphorus were larger than a predetermined amount, the sulfur black coloration was more excellent.

Further, in comparison with Examples 1 to 10 and Examples 11 to 16 using a steel sheet having a Ni-containing layer for securing good weldability, it was confirmed that appearance characteristics were superior in the absence of the Ni-containing layer.

It was also confirmed from Examples 22 to 27 that various effects were more excellent when zirconium oxyacetate or zirconium acetate was used as a supply source (Zr source) of Zr ions in the treatment liquid used for preparing the steel sheet for containers.

On the other hand, the coating film shown in Comparative Example 1 contains Cr although a predetermined effect is obtained.

In addition, as shown in Comparative Examples 2 to 11, when the electric quantity required for reduction of the tin oxide, the amount of the metal zirconium in the film, the amount of the metal titanium, or the amount of the phosphorus is outside the predetermined range, the paint adhesion, It has been confirmed that at least one of the appearance characteristics is poor.

Claims (6)

A steel sheet for a container having a tin-plated layer steel plate having a steel plate and a tin plating layer covering at least a part of a surface of the steel plate and a coating film disposed on the tin plating layer side of the tin-
Wherein the coating contains tin oxide and Zr, Ti and P,
The electricity quantity required for reduction of the tin oxide is 0.20 to 3.50 mC /
Wherein the metal zirconium content in the film is 1.0 to 40.0 mg / m 2, the amount of metal titanium is more than 0.01 mg / m 2 and less than 2.50 mg / m 2, and the phosphorus content is 0.10 to 10.00 mg / m 2. The method according to claim 1,
(Ti / Zr) of 0.1 to 0.4 and an atomic ratio (P / Zr) of P to Zr of 0.7 to 1.4 on the outermost surface of the coating film opposite to the steel sheet side, Steel plate for use. 3. The method according to claim 1 or 2,
Wherein the amount of phosphorus present in the region from the outermost surface of the film to the intermediate portion of the depth corresponding to 1/2 of the total thickness is 70% or more of the total phosphorus content in the film. 3. The method according to claim 1 or 2,
Wherein the tin-plated layer-coated steel sheet is formed by using a steel sheet having a nickel-containing layer on its surface. A steel sheet having a tin plating layer having a steel sheet and a tin plating layer covering at least a part of the surface of the steel sheet is formed by immersing the treatment solution containing Zr ions, Ti ions and phosphorus ions or electrolytically treating the treatment solution A steel plate having a tin plating layer having a steel plate and a tin plating layer covering at least a part of a surface of the steel plate and a coating disposed on the tin plating layer side of the tin plating layer steel plate,
Wherein the coating contains tin oxide and Zr, Ti and P,
The electricity quantity required for reduction of the tin oxide is 0.20 to 3.50 mC /
The amount of metal zirconium in the film is 1.0 to 40.0 mg / m 2, the amount of metal titanium is more than 0.01 mg / m 2 and less than 2.50 mg / m 2, and the phosphorus content is 0.10 to 10.00 mg /
Wherein zirconium oxyacetate or zirconium acetate is used as a source of the Zr ions. The method of claim 3,
Wherein the tin-plated layer-coated steel sheet is formed by using a steel sheet having a nickel-containing layer on its surface.