JP2014088589A - Steel sheet for vessel, treatment liquid used for production thereof, and production method of steel sheet for vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel sheet for a vessel excellent in adhesion to resin and color fastness.SOLUTION: The steel sheet for a vessel has: a steel sheet with a tin plating layer, having a steel sheet and the tin plating layer covering at least a part of a surface of the steel sheet; and a coating film arranged on the surface on the tin plating layer side of the steel sheet with the tin plating layer. The coating film has Zr and Ti, has a coating weight of 1.0 to 40.0 mg/min terms of Zr per one face of the steel sheet with the tin plating layer, has a coating weight of 0.01 mg/mor more and less than 8.0 mg/min terms of Ti per one face of the steel sheet with the tin plating layer, and has a mass ratio between Ti and Zr (Ti/Zr) of 0.01 or more and less than 0.20, and shows an absorption peak derived from a carbonyl group (C=O) in the range of the wave number of 1,550 to 1,800 cmand an absorption peak derived from a secondary hydroxy group (CH-CH) in the range of the wave number of 1,050 to 1,150 cmin an infrared absorption (IR) spectrum of the coating film.

Description

  The present invention relates to a steel plate for containers, a treatment liquid used for manufacturing the same, and a method for manufacturing a steel plate for containers.

As a steel plate for containers (surface-treated steel plate for cans), a tin-plated steel plate conventionally referred to as “blink” has been widely used. In such a tin-plated steel plate, the surface of the tin-plated surface is usually obtained by immersing the steel plate in an aqueous solution containing a hexavalent chromium compound such as dichromic acid, or by performing a chromate treatment such as performing an electrolytic treatment in this solution. A chromate film is formed on the surface.
However, in light of recent environmental problems, movements for restricting the use of Cr have progressed in various fields, and several treatment techniques for replacing chromate treatment have been proposed for steel plates for containers.
For example, Patent Document 1 states that “without using Cr and has excellent resin adhesion” ([0013]), “having a film containing Zr and O on at least one surface of a metal plate, A “surface-treated metal sheet” characterized in that the F amount is less than 0.1 mg / m ² per side ([Claim 1]), where “metal sheet” is “electrical Sn-plated steel sheet”. ([Claim 3]).

JP 2008-184630 A

In recent years, with the increasing demand for consumer aesthetics, further improvements have been required for various properties required for steel plates for containers.
The inventors further studied the steel plate for containers (surface-treated metal plate) disclosed in Patent Document 1. As a result, it was found that when a retort treatment was performed after laminating a resin such as a PET film, the adhesion to the film as the resin (hereinafter also referred to as “resin adhesion”) may be insufficient.
In addition, when the present inventors immerse the laminated steel plate in tomato juice under a predetermined condition, the resin film may be discolored, which is resistant to discoloration (hereinafter also referred to as “discoloration resistance”). I found it inferior. At this time, the present inventors have found that this discoloration is due to oxidation of tin (Sn) contained in the plating layer.

  This invention is made | formed in view of the above point, and it aims at providing the steel plate for containers excellent in resin adhesiveness and discoloration resistance.

As a result of intensive studies to achieve the above object, the present inventors have found that the coating of the steel plate for containers has a specific ratio of Zr and Ti, and further contains a carbonyl group and a secondary hydroxy group. The present inventors have found that the resin adhesion and discoloration resistance are both good and completed the present invention.
That is, the present invention provides the following (1) to (9).

(1) A steel plate with a tin plating layer having a tin plating layer covering at least a part of the surface of the steel plate and the steel plate, and a film disposed on the surface of the steel plate with the tin plating layer on the tin plating layer side. It is a steel plate for containers, and the coating has Zr and Ti, and the coating has a Zr equivalent adhesion amount of 1.0 to 40.0 mg / m ² per one side of the steel plate with the tin plating layer. In addition, the amount of Ti converted per one side of the steel sheet with the tin plating layer is 0.01 mg / m ² or more and less than 8.0 mg / m ² , and the mass ratio of Ti and Zr of the film (Ti / Zr) In the infrared absorption (IR) spectrum of the film, an absorption peak derived from a carbonyl group (C═O) is shown in the range of wave numbers 1550 to 1800 cm ^−1. 1150cm ^-1 Container steel sheet characterized by exhibiting an absorption peak derived from secondary hydroxy group (CH-OH) in circumference.
(2) between the tin-plated layer with the steel sheet and the coating having a phosphorous-containing layer of phosphorus content is less than 0.01 mg / m ² or more 5.00 mg / m ^2, the container according to the above (1) Steel plate.
(3) The steel plate for containers according to (1) or (2), wherein the steel plate with a tin plating layer is formed using a steel plate having a nickel-containing layer on the surface.
(4) A treatment liquid used for producing the container steel plate according to any one of (1) to (3) above, which contains zirconium oxyacetate and titanium lactate. .
(5) The processing liquid according to (4), further comprising an anion that is nitrate ion and at least one cation selected from the group consisting of potassium ion, ammonium ion, and sodium ion.
(6) The above (4) or (5), wherein the content of the zirconium oxyacetate is 0.3 to 15.0 g / L and the content of the titanium lactate is 0.01 to 10.00 g / L. The process liquid as described in.
(7) A method for producing a steel plate for containers, wherein the steel plate for containers according to any one of (1) to (3) above is obtained, and in the treatment liquid according to any one of (4) to (6) above A method for producing a steel plate for containers, comprising: dipping the steel plate with a tin plating layer into the plate or subjecting the immersed steel plate with a tin plating layer to cathodic electrolysis.
(8) A method for producing a steel plate for containers according to (2) or (3) above, wherein the steel plate with a tin plating layer is immersed in a solution containing a phosphorus supply source, or After forming the phosphorus-containing layer by subjecting the immersed steel sheet with the tin plating layer to cathodic electrolysis, the phosphorus-containing layer is contained in the treatment liquid according to any one of (4) to (6). The film is formed by immersing the formed steel sheet with a tin plating layer or by subjecting the tin plate-coated steel sheet with the immersed phosphorus-containing layer formed thereon to cathodic electrolysis. Manufacturing method of steel plate for containers.
(9) The above-mentioned (7), wherein the electrolysis current density at the time of performing the cathodic electrolysis treatment is 0.05 to 7.0 A / dm ² , and the energization time of the cathodic electrolysis treatment is 0.1 to 5 seconds. ) Or the manufacturing method of the steel plate for containers according to (8).

  ADVANTAGE OF THE INVENTION According to this invention, the steel plate for containers excellent in resin adhesiveness and discoloration resistance can be provided.

It is a schematic diagram explaining a 180 degree peel test.

[Steel plate for containers]
The steel plate for containers of the present invention has a steel plate with a tin plating layer and a film disposed on the surface on the tin plating layer side of the steel plate with a tin plating layer. And this film | membrane contains Zr and Ti by specific ratio, and also is excellent in resin adhesiveness and discoloration resistance by containing a carbonyl group (C = O) and a secondary hydroxy group (CH-OH). .
Although the mechanism by which the above effect is obtained is not clear, the Ti compound deposited in the film has a large specific surface area and a needle-like shape, and the adhesion between the resin (film) and the film due to the anchor effect of this compound The formation of a composite compound with Zr in the film suppresses the oxidation of Sn in the tin plating layer by suppressing the diffusion of moisture at a high temperature at the interface between the resin and the film. The reason is that the effect is synergistically improved.
Moreover, it is thought that the diffusion of moisture is suppressed by the decrease in hydrophilicity of the coating surface due to the carbonyl group contained in the coating. Furthermore, the presence of a carbonyl group is considered to improve compatibility with a resin film, particularly a polyester film, and as a result, improve adhesion.
Furthermore, it is considered that the secondary hydroxy group contained in the film further improves the compatibility with a resin film, particularly a polyester film, and improves the adhesion.
Note that the above mechanism is speculative, and it is assumed that the mechanism other than the above mechanism is within the scope of the present invention.

  Below, the steel plate with a tin plating layer and the specific aspect of a membrane | film | coat are explained in full detail. First, the aspect of the steel plate with a tin plating layer is explained in full detail.

<Steel-coated steel sheet>
The steel sheet with a tin plating layer has a tin plating layer that covers at least a part of the surface of the steel sheet and the steel sheet. Below, the aspect of a steel plate and a tin plating layer is explained in full detail.

(steel sheet)
The type of the steel plate in the steel plate with the tin plating layer is not particularly limited, and a steel plate (for example, a low carbon steel plate or an extremely low carbon steel plate) that is usually used as a container material can be used. The manufacturing method and material of the steel plate are not particularly restricted, and the steel plate is manufactured through processes such as hot rolling, pickling, cold rolling, annealing, and temper rolling from a normal steel slab manufacturing process.

If necessary, a steel sheet having a nickel (Ni) -containing layer formed on the surface thereof may be used, and a tin plating layer may be formed on the Ni-containing layer. By performing tin plating using a steel sheet having a Ni-containing layer, a tin plating layer containing island-shaped Sn can be formed, and weldability is improved.
The Ni-containing layer only needs to contain nickel, and examples thereof include a Ni plating layer and a Ni—Fe alloy layer.
The method for applying the Ni-containing layer to the steel plate is not particularly limited, and examples thereof include known methods such as electroplating. Also, when a Ni-Fe alloy layer is applied as the Ni-containing layer, the Ni diffusion layer is coordinated to form a Ni-Fe alloy layer by annealing after applying Ni on the steel sheet surface by electroplating or the like. Can do.
The amount of Ni in the Ni-containing layer is not particularly limited, and is preferably 50 to 2000 mg / m ² as metal Ni equivalent per one side. If it is in the above-mentioned range, it is more excellent in resistance to sulfur blackening and is advantageous in terms of cost.

(Tin plating layer)
The steel plate with a tin plating layer has a tin plating layer on the steel plate surface. The tin plating layer only needs to be provided on at least one side of the steel plate, and may be provided on both sides.
The Sn adhesion amount per one surface of the steel sheet in the tin plating layer is preferably 0.1 to 15.0 g / m ² . When the Sn adhesion amount is within the above range, the outer appearance characteristics and corrosion resistance of the steel plate for containers are excellent. Especially, 0.2-15.0 g / m < ² > is preferable at the point which these characteristics are more excellent, and 1.0-15.0 g / m < ² > is further more preferable at the point which processability is more excellent.

  Note that the Sn adhesion amount can be measured by surface analysis using a coulometric method or fluorescent X-ray. In the case of fluorescent X-rays, a calibration curve relating to the amount of metallic Sn is specified in advance using an Sn adhesion amount sample with a known amount of metallic Sn, and the amount of metallic Sn is relatively identified using the calibration curve.

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

As the tin plating layer, a tin plating layer obtained by plating tin, or by heating and melting tin by energization heating after tin plating, the Fe-Sn alloy layer at the tin plating bottom layer (tin plating / base metal interface) Includes a tin plating layer partially formed.
In addition, as a tin plating layer, tin plating is performed on a steel sheet having a Ni-containing layer on the surface, and tin is further heated and melted by energization heating or the like, and Fe-- is added to the tin plating bottom layer (tin plating / base metal interface). It also includes a tin plating layer in which a part of Sn—Ni alloy, Fe—Sn alloy layer or the like is formed.

As a manufacturing method of a tin plating layer, a known method (for example, an electroplating method or a method of plating by immersing in molten Sn) may be mentioned.
For example, a phenol sulfonate tin plating bath, a methane sulfonate tin plating bath, or a halogen-based tin plating bath is used, and Sn is applied to the surface of the steel sheet so that the adhesion amount per side becomes a predetermined amount (for example, 2.8 g / m ² ). After electroplating, a reflow process is performed at a temperature equal to or higher than the melting point of Sn (231.9 ° C.), and a tin plating layer in which an Fe—Sn alloy layer is formed in the lowermost layer of the tin plating layer can be manufactured. When the reflow process is omitted, a tin plating layer can be produced.

  Also, when the steel sheet has a Ni-containing layer on its surface, a tin plating layer is formed on the Ni-containing layer, and when reflow treatment is performed, the bottom layer of the tin simple plating layer (tin plating / steel sheet interface) is Fe. -Sn-Ni alloy layer, Fe-Sn alloy layer, etc. are formed.

<Film>
A film | membrane is arrange | positioned on the surface by the side of the tin plating layer of the steel plate with a tin plating layer mentioned above.
The coating contains Zr (zirconium element) and Ti (titanium element) as its components. Further, the coating has a Zr equivalent adhesion amount (hereinafter also referred to as “Zr adhesion amount”) of 1.0 to 40.0 mg / m ² per one side of the steel sheet with the tin plating layer, The adhesion amount in terms of Ti per side (hereinafter also referred to as “Ti adhesion amount”) is 0.01 mg / m ² or more and less than 8.0 mg / m ² , and the mass ratio of Ti and Zr of the coating (Ti / Zr) ) Is 0.01 or more and less than 0.20.

If the Zr coating weight of 1.0 mg / m ² or less than 40.0 mg / m ² than is the resin adhesion and tarnish resistance is poor, the resin if 1.0~40.0mg / m ² Excellent adhesion and discoloration resistance. For the reason that these characteristics more excellent is preferably from 5.0~38.0mg / m ^2, more preferably from 9.0~36.0mg / m ^2, 5.0~25.0mg / m is more preferably from ^2, particularly preferably 9.0～22.0Mg / m ^2.

When the amount of Ti adhesion is less than 0.01 mg / m ² or 8.0 mg / m ² or more, the resin adhesion and discoloration resistance are inferior, but 0.01 mg / m ² or more and less than 8.0 mg / m ² excellent resin adhesion and tarnish resistance if the reason that these characteristics more excellent, preferably less than 0.01 mg / m ² ultra ^{2.50mg / m 2, 1.80mg / m} 2 or less and more preferably at, more preferably less than ^{1.5mg / m 2, 0.05~1.3mg / m} 2 is particularly preferred.

  Furthermore, when the mass ratio (Ti / Zr) is less than 0.01, the resin adhesion is inferior. If present, both resin adhesion and resistance to discoloration are excellent. From the reason that these properties are more excellent, 0.010 to 0.18 is preferable, 0.010 to 0.11 is more preferable, 0.04 to 0.18 is further preferable, and 0.05 to 0.11 is preferable. Particularly preferred.

  Further, when the atomic ratio (Ti / Zr) of Ti and Zr on the outermost surface of the film (the outermost surface opposite to the steel plate side) is 0.05 or more, extremely excellent resin adhesion is obtained. If it is less than .40, extremely excellent discoloration resistance is obtained, it is preferably 0.05 or more and less than 0.40, more preferably 0.07 to 0.20, and 0.09 to More preferably, it is 0.14.

In addition, the atomic ratio mentioned above is calculated | required by analyzing and analyzing the peak of Zr3d, Ti3d, and P2p by XPS analysis.
Examples of XPS analysis include the following conditions.
Equipment: Shimadzu / Kratos AXIS-HS
X-ray source: Monochrome AlKα ray (hv = 14866.6 eV)
Measurement area: Hybrid mode 250 × 500 (μm)

Further, in the film, the fluorine amount (F amount in the film) is preferably less than 0.2 mg / m ^{2 and} more preferably less than 0.1 mg / m ² because more excellent resin adhesion and discoloration resistance can be obtained. Is more preferable, less than 0.07 mg / m ² is more preferable, less than 0.05 mg / m ² is particularly preferable, and an aspect in which the film does not substantially contain fluorine (F) is most preferable.

The Zr adhesion amount and Ti adhesion amount described above can be measured by surface analysis using fluorescent X-rays.
The fluorine amount can be calculated based on the Zr adhesion amount measured by the surface analysis using the fluorescent X-ray by measuring the atomic ratio of Zr and F on the outermost surface of the coating by XPS analysis.

  In addition, Zr, Ti, etc. in a film | membrane are each contained as various zirconium compounds and titanium compounds, and the kind and aspect of these compounds are not specifically limited.

And in this invention, the absorption peak derived from a carbonyl group (C = O) is shown in the range of wave numbers 1550-1800 cm < ^-1 > in the infrared absorption (IR) spectrum of a film | membrane. That is, a carbonyl group is contained in the film. Thereby, the steel plate for containers of this invention is excellent in resin adhesiveness and discoloration resistance. In addition, it is thought that the carbonyl group contained in the film is mainly derived from zirconium oxyacetate (zirconyl acetate) [ZrO (CH ₃ COO) ₂ ] contained in the treatment liquid described later.

In the present invention, the infrared absorption (IR) spectrum of the film shows an absorption peak derived from the secondary hydroxy group (CH—OH) in the range of wave numbers from 1050 to 1150 cm ⁻¹ . That is, a secondary hydroxy group is contained in the film. Thereby, the steel plate for containers of this invention is excellent in resin adhesiveness and discoloration resistance. The secondary hydroxy group contained in the film is derived from titanium lactate (dihydroxybis (lactato) titanium) [Ti (OH) ₂ [OCH (CH ₃ ) COOH] ₂ ] contained in the treatment liquid described later. It is considered a thing.

Examples of the measurement conditions of the infrared absorption (IR) spectrum include the following.
Apparatus: FTS-3100 manufactured by Varian
Measuring method: ATR / GE prism Resolution: 4 cm ^-1
Integration count: 32 times

<Phosphorus-containing layer>
The steel plate for containers of the present invention preferably has a phosphorus-containing layer containing P (phosphorus element) between the above-described steel plate with a tin plating layer and the above-described coating. adhesion amount of P in terms of per side of the tin-plated layer with the steel plate (P coating weight)) is, 0.01 mg / m ² or more, preferably has a phosphorous-containing layer is less than 5.00 mg / m ^2.
By having such a phosphorus-containing layer, oxidation of the tin plating layer in the steel plate for containers of the present invention is suppressed, and discoloration resistance is further improved. In the present invention, since the phosphorus-containing layer is covered with the above-described film, the adhesion to a resin such as a PET film is not inferior, and the resin adhesion is good.
And since the discoloration resistance of the steel plate for containers of the present invention is further excellent, the amount of phosphorus in the phosphorus-containing layer is preferably 0.1 to 5.0 mg / m ² , and preferably 0.5 to 3.0 mg / m. ² is more preferable.
Note that the amount of phosphorus in the phosphorus-containing layer can be measured by surface analysis using fluorescent X-rays.

[Manufacturing method and processing solution for steel plate for containers]
The method for producing the container steel plate of the present invention described above is not particularly limited, but the steel plate with a tin plating layer is immersed in a treatment liquid described below (hereinafter, also referred to as “treatment liquid of the present invention”), or By a method (hereinafter also referred to as “production method of the present invention”) including at least a film forming step of forming the above-described film by subjecting a steel sheet with a tin plating layer immersed in the treatment liquid of the present invention to cathodic electrolysis. Preferably there is.
Hereinafter, the production method of the present invention will be described, and in this description, the treatment liquid of the present invention will also be described.

<Film formation process>
The film forming step is a step of forming the above-described film on the surface on the tin plating layer side of the steel plate with the tin plating layer, and immersing the steel plate with the tin plating layer in the treatment liquid of the present invention described later (immersion) Treatment), or a step of subjecting the immersed steel plate to cathodic electrolysis. Cathodic electrolytic treatment is preferable because a uniform film can be obtained at a higher speed than immersion treatment. In addition, you may implement the alternating electrolysis which performs a cathode electrolytic treatment and an anodic electrolytic treatment alternately.
Hereinafter, the treatment liquid of the present invention used, conditions for the cathodic electrolysis, and the like will be described in detail.

(Processing liquid of the present invention)
The treatment liquid of the present invention is for forming the above film containing Zr (zirconium element) and Ti (titanium element), and contains zirconium oxyacetate as a supply source of Zr and as a supply source of Ti. Contains titanium lactate.

Zirconium oxyacetate [ZrO (CH ₃ COO) ₂ ] contained in the treatment liquid of the present invention is also called zirconyl acetate. It is thought that the film formed by the treatment liquid of the present invention containing zirconium oxyacetate has a carbonyl group. Moreover, since a fluorine-based zirconium supply source such as zircon potassium fluoride is not used, the amount of fluorine in the film is reduced. The presence of the carbonyl group in the film and the effect of reducing the amount of fluorine are as described above.
The content of zirconium oxyacetate in the treatment liquid of the present invention is preferably 0.3 to 15.0 g / L, and more preferably 3.0 to 9.0 g / L.

Titanium lactate [Ti (OH) ₂ [OCH (CH ₃ ) COOH] ₂ ] contained in the treatment liquid of the present invention is also called dihydroxybis (lactato) titanium. In the present invention, its ammonium salt (monoammonium salt, Diammonium salt).
When the treatment liquid of the present invention contains such titanium lactate, it is considered that the formed film has secondary hydroxy groups (CH—OH). In addition, since a fluorine-based titanium supply source such as titanium hydrofluoric acid is not used, the amount of fluorine in the film is reduced. The presence of secondary hydroxy groups in the film and the effect of reducing the amount of fluorine are as described above.
As content of the titanium lactate in the process liquid of this invention, 0.01-10.00 g / L is preferable and 0.1-5.0 g / L is more preferable.

Furthermore, the treatment liquid of the present invention preferably contains a conductive aid. Specifically, the conductive aid is selected from the group consisting of anions which are nitrate ions, potassium ions, ammonium ions and sodium ions. And at least one cation.
When the treatment liquid of the present invention contains the conductive aid, the line speed at which the film can be formed can be increased. That is, it is excellent in high-speed operability. This is presumably because the electrical conductivity of the treatment liquid, that is, the liquid resistance is reduced and improved by including the conductive auxiliary agent, and it becomes easy to pass a high current accompanying the increase in speed.
The conductive assistant is substantially contained in the treatment liquid of the present invention as a salt in which the anion and the cation are ion-bonded, and the content thereof is more excellent in high-speed operability. 0.1 to 10.0 g / L is preferable, and 0.5 to 5.0 g / L is more preferable.

  In addition, although water is normally used as a solvent in the processing liquid of this invention, you may use an organic solvent together.

Although the pH of the processing liquid of this invention is not specifically limited, pH 2.0-5.0 are preferable. Within this range, the treatment time can be shortened and the stability of the treatment liquid is excellent.
A known acid component (for example, phosphoric acid, sulfuric acid) / alkali component (for example, sodium hydroxide, aqueous ammonia) can be used to adjust the pH.

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

  Returning to the description of the film forming process again. In the film formation process, the liquid temperature of the treatment liquid at the time of performing the treatment is preferably 20 to 80 ° C., and preferably 40 to 60 ° C. from the viewpoint of film formation efficiency and tissue uniformity and low cost. More preferred.

In the film formation step, the electrolysis current density at the time of carrying out the cathodic electrolysis treatment is preferably a low current density from the reason that the resin adhesion and discoloration resistance of the film to be formed are more excellent. is preferably ^{0.05~7.0A / dm 2, 1.0~2.0A / dm} 2 is more preferable. By using the treatment liquid of the present invention, a film can be formed at a low current density.

At this time, the energization time of the cathodic electrolysis treatment is 0.1 to 5 seconds from the point that the decrease in the adhesion amount is further suppressed and the film can be stably formed, and the characteristic deterioration of the formed film is further suppressed. Preferably, 0.3 to 2 seconds is more preferable.
Moreover, 0.20 to 3.50 C / dm < ² > is preferable and, as for the electric quantity density in the case of cathodic electrolysis processing, 0.40 to 2.00 C / dm < ² > is more preferable.

In addition, in order to remove an unreacted substance after a cathode electrolytic treatment, you may perform the water-washing process and / or drying of the obtained steel plate as needed. In addition, it does not specifically limit about the temperature and system in the case of drying, For example, a normal dryer and an electric furnace drying system are applicable.
In addition, as temperature in the case of a drying process, 100 degrees C or less is preferable. If it is in the said range, the oxidation of a film | membrane can be suppressed and stability of a film | membrane composition is maintained. The lower limit is not particularly limited, but is usually about room temperature.

<Pretreatment process>
The manufacturing method of this invention may be equipped with the pre-processing process demonstrated below before the film formation process mentioned above.
The pretreatment step is a step of subjecting the steel plate with the tin plating layer to cathodic electrolysis in an alkaline aqueous solution (particularly, an aqueous sodium carbonate solution).
Usually, the surface of the tin-plated layer is oxidized to form tin oxide. By subjecting the steel plate to cathodic electrolysis, unnecessary tin oxide can be removed and the amount of tin oxide can be adjusted.
Examples of the solution used for the cathodic electrolysis in the pretreatment step include an alkaline aqueous solution (for example, an aqueous sodium carbonate solution). 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 from the viewpoint that removal of tin oxide proceeds more efficiently. preferable.
The temperature of the alkaline aqueous solution during the cathodic electrolysis is not particularly limited, but is preferably 40 to 60 ° C. The electrolysis conditions (current density, electrolysis time) of the cathodic electrolysis are appropriately adjusted. In addition, you may perform a water washing process after a cathode electrolytic process as needed.

Moreover, the pretreatment process with which the manufacturing method of this invention is provided is not limited to the said process, For example, the steel plate with a tin plating layer is immersed in the solution containing a phosphorus supply source, or the steel plate with the tin plating layer which was immersed It may be a step of performing cathodic electrolysis treatment.
By passing through such a pretreatment process, the phosphorus-containing layer described above is formed on the surface on the tin plating layer side of the steel plate with the tin plating layer. Then, the steel plate with a tin plating layer in which the phosphorus-containing layer is formed undergoes the above-described film formation step, whereby a film is formed.
Here, as a P supply source contained in the solution used in the pretreatment step, for example, phosphoric acid (orthophosphoric acid), sodium phosphate, sodium hydrogen phosphate, primary aluminum phosphate, primary magnesium phosphate, Examples thereof include phosphoric acid such as primary calcium phosphate and / or a salt thereof, and the content thereof is 1.0 to 1.0 from the viewpoint that removal of tin oxide proceeds more efficiently and a desired amount of phosphorus is obtained. 20.0 g / L is preferable, and 8.0 to 12.0 g / L is more preferable.
In the pretreatment step for forming the phosphorus-containing layer, the liquid temperature during immersion or cathodic electrolysis is not particularly limited, but is preferably 40 to 60 ° C. The electrolysis conditions for the cathodic electrolysis are adjusted as appropriate. For example, the electrolysis current density during the cathodic electrolysis is 0.05 to 15.0 A / dm ² from the viewpoint of obtaining a desired amount of phosphorus. Is preferable, and 1.0-12.0 A / dm < ² > is more preferable.
At this time, the energization time of the cathodic electrolysis treatment is not particularly limited, but is preferably 0.1 to 10.0 seconds, and more preferably 0.3 to 7.0 seconds.
In order to obtain a desired amount of phosphorus in a short time, it is preferable to perform cathodic electrolysis.
In addition, you may perform a water washing process after immersion or a cathodic electrolysis process as needed.

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

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Manufacture of steel sheet with tin plating layer>
The steel plate with a tin plating layer was manufactured with the following method.
First, a steel plate (T4 original plate) having a thickness of 0.22 mm is electrolytically degreased, and a nickel plating layer is formed on both sides with a Ni adhesion amount per one side shown in Table 3 using a Watt bath, and then 10 vol.% H ₂ +90 vol. An Fe—Ni alloy layer (Ni-containing layer) (showing Ni adhesion amount in Table 3) was formed on both sides by annealing at 700 ° C. in a .N ₂ atmosphere to diffuse and infiltrate nickel plating.
Subsequently, a steel plate having a Ni-containing layer as the surface layer was formed using a tin plating bath, Sn layers were formed on both sides with the Sn adhesion amount per one side shown in Table 3, and a reflow treatment was performed at a melting point of Sn or higher. Tin plating layers were formed on both sides of the T4 original plate.

<Formation of film>
A steel plate with a tin plating layer was immersed in a 10 g / L sodium carbonate aqueous solution or a 10 g / L phosphoric acid aqueous solution at a bath temperature of 50 ° C., and a cathode electrolytic treatment was performed under the conditions shown in Table 2 (pretreatment) Process).
Thereafter, the obtained steel sheet was washed with water and the treatment liquid (solvent: water) having the composition shown in Table 1 adjusted to pH 2.6 was used, and the bath temperature and electrolysis conditions (current density, energization) shown in Table 2 were used. The cathodic electrolysis treatment was performed at the time and the electric quantity density). Then, the obtained steel plate was washed with water, dried at room temperature using a blower, and a film was formed on both sides (film formation process).

The produced steel sheet was evaluated for resin adhesion and discoloration resistance by the following methods. The amount of each component and the evaluation results are summarized in Table 3.
The phosphorus amount (P amount) of the phosphorus-containing layer, the Zr adhesion amount of the film, and the Ti adhesion amount were measured by the methods described above.
Further, the coating, infrared absorbing (IR) spectra were measured in the range of wave numbers 1550～1800Cm ^-1, absorption peaks derived from the carbonyl group (C = O) is the second in the range of wave number 1050～1150Cm ^-1 It was confirmed whether or not an absorption peak derived from a secondary hydroxy group (CH—OH) was present.

<Resin adhesion>
A laminated steel plate was prepared by laminating an isophthalic acid copolymerized polyethylene terephthalate film having a thickness of 25 μm and a copolymerization ratio of 12 mol% on both surfaces of the produced steel plate for containers. Lamination was performed by sandwiching a steel plate and a film heated to 210 ° C. between a pair of rubber rolls, fusing the film to the steel plate, and cooling with water within 1 sec after passing through the rubber roll. At this time, the feeding speed of the steel plate was 40 m / min, and the nip length of the rubber roll was 17 mm. Here, the nip length is the length in the transport direction of the portion where the rubber roll and the steel plate are in contact. And about the produced laminated steel plate, the following resin adhesiveness evaluation was performed.
Evaluation of resin adhesion was performed by a 180 ° peel test in a retort atmosphere at a temperature of 150 ° C. and a relative humidity of 100%. The 180 ° peel test uses a test piece (size: 30 mm × 100 mm) obtained by cutting a part 3 of the steel plate 1 while leaving the film 2 as shown in FIG. 1A, as shown in FIG. In addition, a film peeling test is performed by attaching a weight 4 (100 g) to one end of the test piece, turning it 180 ° to the film 2 side, and allowing it to stand for 30 minutes. And the peeling length 5 shown in FIG.1 (c) was measured, resin adhesiveness was evaluated as follows, and if it was (double-circle) or (circle), it was considered that resin adhesiveness was favorable.
A: Peel length is less than 10 mm B: Peel length is 10 mm or more and less than 15 mm Δ: Peel length is 15 mm or more and less than 50 mm X: Peel length is 50 mm or more

<Discoloration resistance>
Lamination was performed on both surfaces of the produced steel plate for containers in the same manner as when the resin adhesion was evaluated to produce a laminated steel plate. A test piece (size: 50 mm × 100 mm) of a laminated steel plate was placed in a beaker containing a commercially available tomato juice, and a test was performed in a constant temperature bath at 55 ° C. for 20 days. Discoloration of the gas phase part (part not immersed in tomato juice) was evaluated.
The L value, a value, and b value of the laminated steel sheet before and after the test were measured with a color meter SM-T manufactured by Suga Test Instruments, and the color difference before and after the test was calculated as follows.
ΔE = ((before L test−after L test) ² + (before a test−after a test) ² + (before b test−after b test) ² ) ^0.5
As a result, the discoloration resistance was evaluated as follows, and if it was A or B, it was determined that the discoloration resistance was good.
◎: Color difference is less than 2 ○: Color difference is 2 or more, less than 7 Δ: Color difference is 7 or more, less than 15 ×: Color difference is 15 or more

As is apparent from the results shown in Tables 1 to 3 above, it was confirmed that all of the inventive examples were excellent in resin adhesion and discoloration resistance.
On the other hand, Comparative Examples 1 to 7 in which absorption peaks derived from secondary hydroxy groups were not confirmed from the film were inferior in resin adhesion and discoloration resistance.
Furthermore, Comparative Examples 1, 3, and 6 having a mass ratio (Ti / Zr) of less than 0.01 were inferior in resin adhesion.

DESCRIPTION OF SYMBOLS 1 Steel plate for containers 2 Film 3 Part cut out of steel plate 4 Weight 5 Stripping length

Claims (9)

A steel plate for a container comprising a steel plate and a steel plate with a tin plating layer having a tin plating layer covering at least a part of the surface of the steel plate, and a coating disposed on the surface of the steel plate with the tin plating layer on the tin plating layer side Because
The coating has Zr and Ti;
The coating has a Zr equivalent adhesion amount per side of the steel sheet with the tin plating layer of 1.0 to 40.0 mg / m ² , and has a Ti equivalent adhesion amount per side of the steel sheet with the tin plating layer. 0.01 mg / m ² or more and less than 8.0 mg / m ² ,
The mass ratio (Ti / Zr) of Ti and Zr of the coating is 0.01 or more and less than 0.20,
In infrared absorption (IR) spectrum of the film, the range of wave number 1550～1800Cm ^-1 in an absorption peak attributable to carbonyl group (C = O), secondary hydroxy groups in the range of wave numbers 1050~1150cm ^-1 ( A steel plate for containers which shows an absorption peak derived from (CH-OH). Wherein between the tin-plated layer with the steel sheet and the coating amount of phosphorus has a phosphorus-containing layer is less than 0.01 mg / m ² or more 5.00 mg / m ^2, the container for steel sheet according to claim 1.   The steel plate for containers according to claim 1 or 2, wherein the steel plate with a tin plating layer is formed using a steel plate having a nickel-containing layer on the surface. It is the processing liquid used for manufacture of the steel plate for containers according to any one of claims 1 to 3,
A treatment liquid comprising zirconium oxyacetate and titanium lactate.   Furthermore, the processing liquid of Claim 4 containing the anion which is a nitrate ion, and the at least 1 sort (s) of cation chosen from the group which consists of potassium ion, ammonium ion, and sodium ion.   The processing liquid according to claim 4 or 5, wherein the content of the zirconium oxyacetate is 0.3 to 15.0 g / L, and the content of the titanium lactate is 0.01 to 10.00 g / L. It is a manufacturing method of the steel plate for containers which obtains the steel plate for containers given in any 1 paragraph of Claims 1-3,
The said film | membrane is formed by immersing the said steel plate with a tin plating layer in the processing liquid of any one of Claims 4-6, or performing a cathode electrolytic treatment to the immersed said steel plate with a tin plating layer The manufacturing method of the steel plate for containers characterized by performing. It is a manufacturing method of the steel plate for containers which obtains the steel plate for containers according to claim 2 or 3,
After forming the said phosphorus containing layer by immersing the said steel plate with a tin plating layer in the solution containing a phosphorus supply source, or performing a cathodic electrolysis process to the immersed said steel plate with a tin plating layer, Claim 4 ~ The steel plate with a tin plating layer in which the steel plate with a tin plating layer in which the phosphorus-containing layer is formed is immersed in the treatment liquid according to any one of 6 or the steel plate with a tin plating layer in which the immersed phosphorus-containing layer is formed. A method for producing a steel plate for containers, wherein the film is formed by performing cathodic electrolysis on the container. The electrolysis current density at the time of performing the cathodic electrolysis treatment is 0.05 to 7.0 A / dm ² , and the energization time of the cathodic electrolysis treatment is 0.1 to 5 seconds. The manufacturing method of the steel plate for containers of description.

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