JP2016102252A - Steel sheet for vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel sheet for a vessel excellent in both PET film adhesion and coating film adhesion.SOLUTION: Provided is a sheet for a vessel having a plated steel sheet covering at least a part of the surface of a steel with a plating layer made of at least one layer selected from an Ni layer, an Sn layer, an Ni-Fe alloy layer, an Fe-Sn-Ni alloy layer and an Fe-Sn alloy layer and a film formed on the surface of the plating layer in the plated steel sheet, in which the film contains Ti, Ni and C, in the film, the coating weight in terms of Ti per side of the plated steel sheet is 5.0 to 60.0 mg/m, the coating weight in terms of Ni per side of the plated steel is 0.1 to 3.0 mg/m, and the film in which the mass ratio of C to Ti in the film (C/Ti) is 0.01 to 10 is formed by cathode electrolysis or the like.SELECTED DRAWING: None

Description

  The present invention relates to a steel plate for containers.

  As a steel plate (container steel plate) used for a container such as a can, for example, Patent Document 1 discloses that “at least one surface of a steel plate is Ni layer, Sn layer, Fe—Ni alloy layer, Fe—Sn alloy layer and Fe— It has a corrosion-resistant film composed of at least one layer selected from Ni-Sn alloy layers, contains Ti on the corrosion-resistant film, and is further selected from Co, Fe, Ni, V, Cu, Mn and Zn. A surface-treated steel sheet having an adhesive film containing 0.01 to 10 as a total mass ratio of at least one of the above-described materials is disclosed ([Claim 1]).

JP 2010-031348 A

  As a result of studying the steel plate for containers (surface-treated steel plate) described in Patent Document 1, the present inventors have found that the adhesiveness to the PET film (hereinafter also referred to as “film adhesiveness”) and the adhesiveness to the paint (hereinafter referred to as “film adhesiveness”) It was found that at least one of "paint adhesion" may be insufficient.

  This invention is made | formed in view of the above point, and it aims at providing the steel plate for containers which is excellent in both film adhesiveness and paint adhesiveness.

  As a result of intensive studies to achieve the above object, the present inventors have found that a steel plate for containers obtained by forming a coating containing a specific amount of Ti, Ni and C on a plated steel plate has film adhesion and The inventors found that the paint adhesion was excellent and completed the present invention.

That is, the present invention provides the following [1] to [5].
[1] A plating layer comprising at least one layer selected from a Ni layer, a Sn layer, a Ni—Fe alloy layer, a Fe—Sn—Ni alloy layer, and a Fe—Sn alloy layer covering at least part of the surface of the steel sheet A steel plate for a container having a plated steel plate having a coating and a coating disposed on the surface of the plated steel plate on the plating layer side, wherein the coating contains Ti, Ni, and C, adhesion amount of Ti in terms of per side of the plated steel sheet is less than 5.0 mg / m ² or more 60.0 mg / m ^2, the adhesion amount of Ni converted per one surface of the plated steel sheet is 0.1-3.0 mg / The steel plate for containers which is m < ² > and the mass ratio (C / Ti) with respect to Ti of C in the said film | membrane is 0.01-10.
[2] The above coating, the adhesion amount of Ti converted per one surface of the plated steel sheet is 10.0~30.0mg / m ^2, the container for steel sheet according to [1].
[3] The steel plate for containers according to [1] or [2] above, wherein a T value defined by the formula (2) described later is 0.50 or less.
[4] The steel plate for containers according to any one of [1] to [3], wherein the plating layer is a tin plating layer, and the coating includes a Ni—Sn alloy phase.
[5] The steel plate for containers according to any one of [1] to [4], wherein C contained in the film is derived from a phenol resin or a phenol compound.

  ADVANTAGE OF THE INVENTION According to this invention, the steel plate for containers which is excellent in both film adhesiveness and paint adhesiveness can be provided.

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

[Steel plate for containers]
The container steel plate of the present invention generally has a plated steel plate and a film disposed on the surface of the plated steel plate.
Below, the specific aspect of a plated steel plate and a membrane | film | coat is explained in full detail. First, the aspect of a plated steel plate is explained in full detail.

[Plated steel sheet]
The plated steel plate is at least one layer selected from a steel plate and a Ni layer, a Sn layer, a Ni—Fe alloy layer, a Fe—Sn—Ni alloy layer and a Fe—Sn alloy layer covering at least a part of the surface of the steel plate. And a plating layer.
As a raw steel plate, a general steel plate for cans can be used. A plating layer is a layer which covers at least one part on the steel plate surface, A continuous layer may be sufficient and a discontinuous island shape may be sufficient as it. Moreover, the plating layer should just be provided in the at least single side | surface of the steel plate, and may be provided in both surfaces. The plating layer can be formed by a known method according to the contained element.
Below, the suitable aspect of a steel plate and a plating layer is explained in full detail.

<steel sheet>
The kind of steel plate is not particularly limited. Usually, a steel plate (for example, a low carbon steel plate or an ultra low carbon steel plate) used as a container material can be used. The manufacturing method and material of the steel plate are not particularly limited. It is manufactured through processes such as hot rolling, pickling, cold rolling, annealing, temper rolling and the like from a normal billet 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 to be described later 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. As a result, weldability is improved.
The Ni-containing layer only needs to contain nickel. For example, a Ni plating layer (Ni layer), a Ni—Fe alloy layer, and the like can be given.
The method for applying the Ni-containing layer to the steel plate is not particularly limited. For example, a known method such as electroplating can be used. Moreover, when providing a Ni-Fe alloy layer as a Ni-containing layer, Ni can be diffused in the steel by annealing after applying Ni on the steel sheet surface by electroplating or the like, thereby forming a Ni-Fe alloy layer.
The Ni adhesion amount in the Ni-containing layer is not particularly limited, and is preferably 50 to 2000 mg / m ² as the Ni conversion amount per one side. If it is in the said range, it will become advantageous also in terms of cost.

The Ni adhesion amount can be measured by surface analysis with fluorescent X-rays. In this case, a calibration curve related to the Ni adhesion amount is specified in advance using a Ni adhesion sample with a known Ni adhesion amount, and the Ni adhesion amount is relatively specified using the calibration curve.
However, as will be described later, since the film contains Ni, it is difficult to measure only the Ni adhesion amount in the Ni-containing layer by the surface analysis using the fluorescent X-ray. For this reason, the Ni adhesion amount in the Ni-containing layer can be obtained by subtracting the Ni adhesion amount contained in the film described later from the Ni adhesion amount obtained by fluorescent X-rays.

<Plating layer>
As a plating layer which a plated steel plate has on the steel plate surface, a plating layer containing Sn (hereinafter also referred to as “tin plating layer”) is preferable. The tin plating layer should just be provided in the at least single side | surface of the steel plate, and may be provided in both surfaces. 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.

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 the corrosion resistance of the steel plate for containers are excellent. Among them, in that these characteristics are more excellent, more preferably 0.2~15.0g / m ^2, in terms of corrosion resistance more excellent, more preferably 1.0~15.0g / m ^2.
The Sn adhesion amount can be measured by surface analysis with fluorescent X-rays. In the case of fluorescent X-rays, a calibration curve relating to the Sn amount is specified in advance using a Sn deposition amount sample with a known Sn amount, and the Sn deposition amount is relatively identified using the calibration curve.

As the tin plating layer, in addition to a tin plating layer composed of an Sn layer obtained by plating tin, the tin plating layer obtained by heating and melting tin by energization heating after tin plating, etc. It also includes a tin plating layer in which a Fe—Sn alloy layer is partially formed in the lower layer (Sn layer / steel plate interface) or a tin plating layer in which all Sn of the Sn layer is alloyed to form an Fe—Sn alloy layer.
In addition, as the tin plating layer, the lowermost layer of the Sn layer (Sn layer / steel plate interface) obtained by tin-plating a steel plate having a Ni-containing layer on the surface and further heating and melting tin by electric heating or the like A tin-plated layer in which a Fe-Sn-Ni alloy layer, a Fe-Sn alloy layer, etc. are partially formed, or all Sn in the Sn layer is alloyed to form a Fe-Sn-Ni alloy layer and a Fe-Sn alloy layer. Also includes a tin plating layer.

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 electroplated on the surface of the steel sheet so that the adhesion amount per one surface becomes a predetermined amount. Then, heat melting treatment is performed at a temperature equal to or higher than the melting point of Sn (231.9 ° C.), and the lowermost layer of the tin simple substance plating layer (Sn layer) or all Sn in the Sn layer is alloyed to form an Fe—Sn alloy layer A tin-plated layer can be produced. When the heat melting treatment is omitted, a tin simple plating layer (Sn layer) can be produced.

  Further, when the steel sheet has a Ni-containing layer on its surface, tin plating is performed on the Ni-containing layer to form a tin simple plating layer (Sn layer), and when the heat melting treatment is performed, the bottom layer of the Sn layer (Sn layer / steel plate interface) or all Sn in the Sn layer is alloyed to form an Fe—Sn—Ni alloy layer, an Fe—Sn alloy layer, or the like.

[Coating]
Next, the film | membrane arrange | positioned on the surface by the side of the plating layer of the plated steel plate mentioned above is demonstrated. The coating is roughly a coating containing Ti (titanium element), Ni (nickel element), and C (carbon element) as its components, and is formed using a treatment liquid described later.
In addition, Ti, Ni, C, and the like in the film are included as various titanium compounds, nickel compounds, and carbon compounds, respectively, and the types and modes of these compounds are not particularly limited.

The present inventors have found that the film adhesion and paint adhesion are excellent when the coating contains Ti, Ni and C in specific amounts.
Specifically, a certain amount of Ni and C is required in the film, but if Ni is excessively present in the film, film adhesion and paint adhesion are deteriorated. The mechanism (reason) is not clear, but if a certain amount or more of Ni is not present in the film containing Ti, the film formation and the adhesion between the film and the steel sheet will be insufficient. It is considered that Ni is precipitated in the form of particles and prevents adhesion between the film and the film or paint.
Moreover, when the mass ratio of C to Ti in the film is within a certain range, film adhesion and paint adhesion are excellent. Although the mechanism (reason) is not clear, C in the film forms a chemical bond with the film or paint that is an organic resin to improve adhesion to the film and the film or paint. If the amount is too small, this effect is small. On the other hand, if the amount is too large, the strength of the coating itself is lowered and the adhesiveness is still poor.
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.

<Ti adhesion amount>
The coating has a Ti-equivalent adhesion amount (hereinafter also referred to as “Ti adhesion amount”) per side of the plated steel sheet of 5.0 mg / m ² or more and less than 60 mg / m ² . If the Ti adhesion amount is less than 5.0 mg / m ² or 60 mg / m ² or more, the film adhesion and paint adhesion are inferior, but if it is 5.0 mg / m ² or more and less than 60 mg / m ² , the film adhesion and Excellent paint adhesion. Ti adhesion amount, for the reason that the film adhesion and coating adhesion more excellent, preferably ^{10~30mg / m 2, 10~20mg / m} 2 is more preferable.

<Ni adhesion amount>
The coating has an Ni conversion amount (hereinafter also referred to as “Ni adhesion amount”) of 0.1 to 3.0 mg / m ² per one side of the plated steel sheet. When the Ni adhesion amount is 0.1 to 3.0 mg / m ² , the corrosion resistance is also excellent. Here, the corrosion resistance is specifically the corrosion resistance of the scratched part (scratches reaching the steel plate) when the steel plate for containers is immersed in an acidic aqueous solution in a state where the PET film is laminated and a paint is applied ( And “corrosion resistance after film application” and “corrosion resistance after painting”, respectively).
From the reason that the corrosion resistance is more excellent, the Ni adhesion amount is preferably 0.1 to 1.3 mg / m ² .

<Mass ratio (C / Ti)>
The mass ratio of C to Ti (C / Ti) in the coating is 0.01-10. A film or paint in which C in the film is an organic resin generates a chemical bond to improve adhesion to the film and the film or paint, but this effect is achieved when the mass ratio (C / Ti) is less than 0.01. Not enough. On the other hand, if the mass ratio (C / Ti) is more than 10, the strength of the coating itself is lowered and the adhesion is also inferior. However, when the mass ratio (C / Ti) is in the range of 0.01 to 10, the film adhesion and the paint adhesion are excellent.
The mass ratio (C / Ti) is preferably 0.10 to 5, more preferably 0.20 to 5, and further preferably 0.20 to 2, because the film adhesion is more excellent.

  In addition, when the adhesion amount in terms of C per one side of the coated steel sheet is “C adhesion amount”, the mass ratio (C / Ti) is a value of the ratio between the C adhesion amount and the Ti adhesion amount.

Ti adhesion amount, Ni adhesion amount, and C adhesion amount are measured by surface analysis using fluorescent X-rays.
The fluorescent X-ray analysis is performed, for example, under the following conditions.
Apparatus: X-ray fluorescence analyzer System 3270 manufactured by Rigaku Corporation
・ Measurement diameter: 30 mm
Measurement atmosphere: Vacuum Spectrum: Ti-Kα, Ni-Kα, C-Kα
・ Slit: COARSE
-Spectral crystal: LiF (Ti, Ni), RX (C)
The peak count numbers of Ti-Kα, Ni-Kα, and C-Kα in the fluorescent X-ray analysis of the film measured under the above conditions are used.

However, when the plating layer contains Ni, it is difficult to measure only the Ni adhesion amount contained in the film by the surface analysis using the fluorescent X-ray.
In that case, the Ni adhesion amount contained in the film can be obtained by using both the cross-sectional observation by a scanning electron microscope (SEM) and a transmission electron microscope (TEM) and the glow discharge emission analysis. The amount of Ni contained in the plating layer can be distinguished.
Specifically, the cross section of the coating and the plating layer is exposed by focused ion beam (FIB) processing, and the thickness of the coating is calculated from cross-sectional observation by SEM or TEM. Next, the relationship between the sputtering depth and the sputtering time by glow discharge emission analysis is obtained. Thereafter, the integrated emission count value by Ni element of the glow discharge emission analysis up to the sputtering time corresponding to the film thickness is obtained. From the integrated emission count value of the Ni element, the Ni adhesion amount can be obtained using a calibration curve obtained in advance.
Here, the calibration curve is created by the following method.
First, glow discharge emission analysis is performed on a plurality of samples having a coating film containing Ni on a plating layer not containing Ni and having different Ni adhesion amounts, and a count integrated value up to a sputtering time at which no emission count due to Ni element is detected is obtained. . Next, the Ni adhesion amount of these samples is obtained by surface analysis using fluorescent X-rays. In this way, a calibration curve between the Ni count integrated value and the Ni adhesion amount by glow discharge emission analysis is created.

<thickness>
10-120 nm is preferable and, as for the thickness of a film | membrane, 20-60 nm is more preferable. The thickness of the film can be measured from a cross-sectional profile obtained by observation with a transmission electron microscope (TEM) after exposing the cross section of the film by focused ion beam (FIB) processing.

<T value>
The film preferably has a T value defined by the following formula (2) of 0.50 or less.
T = [Ii (F) -Ib (F)] / Ib (F) (2)
In formula (2), Ii (F) represents the F peak count number of fluorescent X-ray analysis of the film before dipping the steel plate for containers of the present invention in boiling water for 30 minutes, and Ib (F) represents the present invention. The F peak count number of the fluorescent X-ray analysis of the film | membrane after immersing the steel plate for containers of for 30 minutes in boiling water is represented.
Here, [Ii (F) -Ib (F)] indicates the F amount eluted by immersion in boiling water, and the T value defined by the equation (2) obtained by dividing this by Ib (F) is It becomes an index indicating the ratio of the soluble F amount in the film. When this T value is 0.50 or less, the film adhesion of the resulting steel plate for containers is more excellent.

Note that the fluorescent X-ray analysis is performed, for example, under the following conditions.
Apparatus: X-ray fluorescence analyzer System 3270 manufactured by Rigaku Corporation
・ Measurement diameter: 30 mm
・ Measurement atmosphere: Vacuum ・ Spectrum: F-Kα
・ Slit: COARSE
-Spectral crystal: TAP
The peak count number of F-Kα in the fluorescent X-ray analysis of the film measured under the above conditions is used.

<Ni-Sn alloy phase>
Moreover, when a plating layer is the tin plating layer mentioned above, it is preferable that a membrane | film | coat contains a Ni-Sn alloy phase.
“Ni” in the Ni—Sn alloy phase is derived from Ni in the film, and “Sn” is derived from Sn in the tin plating layer. Such a Ni—Sn alloy phase may be deposited as a continuous layer at the interface between the coating and the tin plating layer in the coating, or intermittently deposited as particles dispersed in the coating. Or both.
When Sn of the tin plating layer enters the film and reaches near the surface, the color tone of the film may be inferior. However, if the Ni—Sn alloy phase is precipitated in the film, the penetration of Sn is suppressed and the color tone is reduced. It becomes good. In addition, film adhesion and paint adhesion are also superior.
In addition, as a method of confirming the presence or absence of the Ni—Sn alloy phase in the film, for example, transmission electron microscope (TEM) electron diffraction or energy dispersive X-ray spectrometry (Energy dispersive X-ray spectrometry) : EDX), a point analysis or a line analysis may be performed on the surface or cross section of a sample produced by an extraction replica method or a focused ion beam (FIB) process.

[Manufacturing method of steel plate for containers]
As a method for producing the above-described steel plate for containers of the present invention, for example, a method comprising at least a film forming step described later (hereinafter also referred to as “the production method of the present invention” for convenience) is preferable.

[Film formation process]
The film forming step is performed by immersing the plated steel sheet in a treatment liquid (hereinafter also referred to as “treatment liquid of the present invention” for convenience) (immersion treatment) or by immersing the plated steel sheet in the treatment liquid of the present invention. This is a step of forming the above-described film on the surface of the plated steel sheet on the plated layer side by subjecting to a cathodic electrolytic treatment. 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>
<< Ti component of treatment liquid >>
The treatment liquid of the present invention contains a Ti component (Ti compound) for supplying Ti (titanium element) to the film.
The Ti component is not particularly limited. For example, titanium alkoxide, titanyl ammonium oxalate, potassium titanyl oxalate dihydrate, titanium sulfate, titanium lactate, titanium hydrofluoric acid (H ₂ TiF ₆ ) and / or its Examples include salt. Examples of the salt of titanium hydrofluoric acid include potassium hexafluorotitanate (K ₂ TiF ₆ ), sodium hexafluorotitanate (Na ₂ TiF ₆ ), and ammonium hexafluorotitanate ((NH ₄ ). ₂ TiF ₆ ) and the like.
Of these, titanium hydrofluoric acid and / or a salt thereof is preferable from the viewpoints of stability of the treatment liquid, availability, and the like.
The content of the Ti component in the treatment liquid of the present invention is not particularly limited, but when using titanium hydrofluoric acid and / or a salt thereof, the amount converted to hexafluorotitanate ion (TiF ₆ ²⁻ ), 0.004 to 0.4 mol / L is preferable, and 0.02 to 0.2 mol / L is more preferable.

<< Ni component of treatment liquid >>
The treatment liquid of the present invention contains a Ni component (Ni compound) for supplying Ni (nickel element) to the film.
As the Ni component is not particularly limited, nickel sulfate (NiSO _4), nickel sulfate hexahydrate, nickel chloride (NiCl _2), etc. nickel chloride hexahydrate and the like.
The content of the Ni component in the treatment liquid of the present invention is not particularly limited, but the amount converted to Ni ions (Ni ²⁺ ) is preferably 0.002 to 0.04 mol / L, and is preferably 0.004 to 0. 0.02 mol / L is more preferable.

<< C component of treatment liquid >>
The treatment liquid of the present invention contains a C component (C compound) for supplying C (carbon element) to the film.
As this C component, a phenol resin or a phenol compound is mentioned, for example. For example, in a treatment liquid of the present invention to which a phenol resin or a phenol compound is added, by subjecting a plated steel plate to cathodic electrolysis, C (phenol resin) is precipitated in Ti, and a film containing C is formed. .

  Although it does not specifically limit as a phenol resin, For example, what gave water solubility by carrying out amino alcohol modification | denaturation of a phenol resin is mentioned.

  Moreover, as a phenol compound, a tannic acid is mentioned, for example. Tannic acid is a general term for an aromatic compound having a complex structure having a large number of phenolic hydroxyl groups widely distributed in the plant kingdom, and may be hydrolyzable tannic acid or condensed tannic acid. The tannic acid is not particularly limited, and examples thereof include hameli tannin, oyster tannin, chatannin, pentaploid tannin, gallic tannin, mylobalantannin, dibidi tannin, algarobilatannin, valonia tannin, catechin tannin and the like. As such tannic acid, a commercially available product can be used, and specific examples include “tannic acid” manufactured by Fuji Chemical Industry Co., Ltd.

  Although the weight average molecular weight of a phenol resin or a phenol compound is not specifically limited, 500-20,000 are preferable and 1,000-5,000 are more preferable. The weight average molecular weight is a weight average molecular weight (polystyrene conversion) measured by gel permeation chromatography (GPC).

The content of the C component in the treatment liquid of the present invention is preferably a mass ratio of C to Ti (C / Ti) of 0.01 to 10. If the mass ratio (C / Ti) is too small, the effect of improving the adhesion may be small, and if it is too large, the film may be difficult to precipitate. Is sufficiently improved.
The mass ratio (C / Ti) is preferably 0.1 to 1.0.

《Other conditions of processing solution》
As the solvent in the treatment liquid of the present invention, water is usually used, but an organic solvent may be used in combination.
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.
Further, 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.
20-80 degreeC is preferable and, as for the liquid temperature of the processing liquid of this invention, 40-60 degreeC is more preferable.

<Cathode electrolysis conditions>
In the film formation step, the electrolysis current density at the time of carrying out the cathodic electrolysis treatment is 1.0 because Ti and Ni in the formed film are appropriate amounts, and the film adhesion and paint adhesion are more excellent. ˜20.0 A / dm ² is preferable, and 3.0 to 15.0 A / dm ² is more preferable.
The energization time of the cathodic electrolysis treatment is preferably 0.1 to 5 seconds, and more preferably 0.3 to 2 seconds.
The quantity of electricity at the time of cathodic electrolysis is the product of the current density and the energization time, and is appropriately set.

In order to reduce F contained in the film, it is preferable to perform a water washing treatment of the obtained steel sheet after the cathodic electrolysis treatment.
The method of the water washing treatment is not particularly limited. For example, in the case of production in a continuous line, a water washing tank is provided after the treatment liquid tank of the present invention, and a method of continuously immersing in water after the treatment for forming a film, etc. Is mentioned. The temperature of the water used for the water washing treatment is preferably 40 to 90 ° C.
The washing time is preferably more than 0.5 seconds, and more preferably 1.0 to 5.0 seconds, because the effect of the washing treatment is more excellent.
Further, drying may be performed instead of or after the washing process. The temperature and method during drying are not particularly limited, and for example, a normal dryer or an electric furnace drying method can be applied. The temperature during the drying treatment is preferably 100 ° C. or lower. 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.

  In addition, the Ni-Sn alloy phase mentioned above is formed in a membrane | film | coat by performing the membrane | film | coat formation process mentioned above using the processing liquid of this invention with respect to the plated steel plate which has a tin plating layer.

[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 plated steel plate to cathodic electrolysis in an alkaline aqueous solution (particularly, an aqueous sodium carbonate solution).
When the plating layer is a tin plating layer, the surface is usually oxidized during the production of the tin plating layer to form tin oxide. By subjecting the plated steel sheet having such a tin plating layer 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.

  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 plated steel sheets>
A plated steel sheet was produced by 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 Ni—Fe 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 the nickel plating.
Subsequently, the steel sheet having the Ni-containing layer as the surface layer was subjected to tin plating on both sides with a Sn adhesion amount per one side shown in Table 3 using a tin plating bath. Thereafter, heat melting treatment was performed at a melting point of Sn or higher to form a Fe—Sn—Ni alloy layer and a discontinuous Sn layer thereon, and a plated steel sheet was manufactured. Thus, the plating layer which consists of a Ni-Fe alloy layer / Fe-Sn-Ni alloy layer / Sn layer was formed in order from the lower layer side on both surfaces of the steel plate.

<Production of test materials for steel plates for containers>
A test material for a steel plate for containers was produced as follows using the produced plated steel plate.

<< Pretreatment process >>
The plated steel sheet was immersed in a 10 g / L sodium carbonate aqueous solution at a liquid temperature of 50 ° C., and cathodic electrolysis was performed under the conditions shown in Table 2.

<Film formation process>
Next, using the treatment liquid (solvent: water) having the composition shown in Table 1 with pH adjusted to 4.0, the liquid temperature (treatment temperature) and electrolysis conditions (current density, energization time, amount of electricity shown in Table 2) The cathode was subjected to cathodic electrolysis treatment. Thereafter, the film was washed with water by immersing it in a water bath at 85 ° C. for 0.2 seconds, and dried at room temperature using a blower to form films on both sides.
In addition, a phenol resin having a weight average molecular weight of 5,000 was used as the phenol resin contained in the treatment liquid, and tannic acid manufactured by Fuji Chemical Industry Co., Ltd. having a weight average molecular weight of 2,000 was used as the phenol compound.

Thereafter, film adhesion, paint adhesion, and corrosion resistance were evaluated by the following methods for the test materials for the produced steel plates for containers. The amount of each component and the evaluation results are summarized in Table 3.
The coating amount of Ti, the coating amount of Ni and the mass ratio (C / Ti), Ii (F), Ib (F) and T, the thickness of the coating, and the presence or absence of the Ni-Sn alloy phase in the coating are described above. Measured or calculated by the method described above.

<Film adhesion>
As evaluation of film adhesiveness, the following non-processed film adhesiveness and post-processing film adhesiveness were evaluated. If it is not evaluated that either the unprocessed film adhesion or the processed film adhesion is excellent, the film adhesion is inferior.

《Unprocessed film adhesion》
A commercially available PET film (Melinex 850: manufactured by DuPont) is applied to the surface of the produced steel plate for containers under the conditions that the roll pressure is 4 kg / cm ² , the plate feed speed is 40 mpm, and the surface temperature of the plate after passing through the roll is 160 ° C. Then, heat-sealing was carried out, followed by post-heating in a batch furnace (holding at a final plate temperature of 210 ° C. for 120 seconds) to produce a laminated steel plate.
Evaluation of unprocessed film adhesion was performed by holding the produced laminated steel sheet in a retort atmosphere at a temperature of 130 ° C. and a relative humidity of 100% for 30 minutes, and then performing a 180 ° peel test in this retort atmosphere.
The 180 degree 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, it is a film peeling test performed by attaching a weight 4 (100 g) to one end of the test piece, turning it 180 degrees to the film 2 side, and allowing it to stand for 30 minutes.
The peel length 5 shown in FIG. 1 (c) was measured. The unprocessed film adhesion was evaluated according to the following criteria. If a result is (double-circle) or (circle), it can evaluate as what is excellent in unprocessed film adhesiveness.
A: Peel length is less than 1 mm B: Peel length is 1 mm or more and less than 5 mm Δ: Peel length is 5 mm or more and less than 10 mm ×: Peel length is 10 mm or more

<Film adhesion after processing>
Using a punch with a tip diameter of 3/16 inch R, a 1 kg weight is dropped from a height of 25 cm to the laminated steel plate produced by the above method, and DuPont impact processing is performed so that the side with the film attached becomes convex. It was. Four such processed test pieces are prepared, placed in the retort device so that the convex surface is on top, held for 30 minutes in a retort environment at 130 ° C., taken out, and visually checked the degree of film peeling of the processed part, Evaluation was made according to the following 5 levels. The film adhesion after processing was evaluated using the average value (one decimal place) of the four test pieces. Practically, if the result is 3.0 or more, it can be evaluated as having excellent film adhesion after processing.
5: No peeling 4: Peeling occurs when less than 5% of the area of the processed part 3: Peeling occurs when the area of the processed part is 5% or more and less than 20% 2: Peeling occurs when the area of the processed part is 20% or more and less than 50% 1 : Peeling occurs at 50% or more of the processed area

<Paint adhesion>
An epoxy phenol-based paint was applied to the surface of the produced steel plate for containers (width 100 mm × length 150 mm), and baked at 210 ° C. for 10 minutes to give a coating amount of 50 mg / dm ² .
Next, after laminating the two coated steel plates prepared under the same conditions with the above coating so that the coated surfaces face each other across the nylon adhesive film, the pressure is 2.94 × 10 ⁵ Pa, Bonding was performed under pressure bonding conditions of a temperature of 190 ° C. and a pressure bonding time of 30 seconds. Then, this was divided into 5 mm wide test pieces. Two container steel plates of the divided test pieces were peeled off by a tensile tester, and the tensile strength when peeled off was measured. For each test material, the average value of the two test pieces was evaluated according to the following criteria. Practically, if the result is ○ or Δ, it can be evaluated as having excellent paint adhesion.
○: 2.0 kgf or more Δ: 1.0 kgf or more and less than 2.0 kgf ×: Less than 1.0 kgf

<Corrosion resistance after film application>
A cross-cut having a depth reaching the base iron (steel plate) was put on the film surface of the laminated steel plate (width 70 mm × length 40 mm) produced by the above method using a cutter. The laminated steel sheet with the cross cut was immersed in a test solution at 55 ° C. composed of a mixed aqueous solution containing 1.5 mass% citric acid and 1.5 mass% sodium chloride for 96 hours. After dipping, washing and drying, a cellophane adhesive tape was applied to the film surface, and the tape was peeled off. The film peeling width (total width on the left and right extending from the cut portion) was measured at any four locations at the center of the cross cut portion, and the average value of the four locations was determined. The average value of the film peeling width was regarded as the corrosion width and evaluated according to the following criteria. Practically, if the result is ま た は or ◯, it can be evaluated as having excellent corrosion resistance.
◎: Corrosion width less than 0.8 mm ○: Corrosion width 0.8 mm or more and less than 1.5 mm △: Corrosion width 1.5 mm or more and less than 2.0 mm ×: Corrosion width 2.0 mm or more

<Corrosion resistance after painting>
An epoxy phenol-based paint was applied to the surface of the produced steel plate for containers (width 70 mm × length 40 mm), and baked at 210 ° C. for 10 minutes to give a coating amount of 50 mg / dm ² .
Next, a cross-cut having a depth reaching the ground iron (steel plate) was put on the coated surface of the coated steel plate (painted steel plate) using a cutter. The coated steel sheet with the cross cut was immersed in a test solution at 55 ° C. composed of a mixed aqueous solution containing 1.5% by mass citric acid and 1.5% by mass sodium chloride for 96 hours. After immersion, after washing and drying, a cellophane adhesive tape was applied to the coating film, and the tape was peeled off. The film peeling width (total width on the left and right extending from the cut portion) was measured at any four locations at the center of the cross cut portion, and the average value of the four locations was determined. The average value of the film peeling width was regarded as the corrosion width and evaluated according to the following criteria. Practically, if the result is ま た は or ◯, it can be evaluated as having excellent corrosion resistance.
◎: Corrosion width less than 0.2 mm ○: Corrosion width 0.2 mm or more and less than 0.6 mm △: Corrosion width 0.6 mm or more and less than 1.0 mm ×: Corrosion width 1.0 mm or more

As is clear from the results shown in Tables 1 to 3 above, all of the inventive examples (test materials No. 7 to 23) are excellent in both film adhesion and paint adhesion, and are further resistant to corrosion (corrosion resistance after film application). It was also confirmed that it was excellent in corrosion resistance after painting.
On the other hand, the comparative example (test material No. 1-3) whose mass ratio (C / Ti) is less than 0.01 is at least any of non-processed film adhesiveness, post-processed film adhesiveness, and paint adhesiveness. It was inferior.
Moreover, the comparative example (test material No. 4-6) whose Ni adhesion amount is less than 0.1 mg / m < ² > was inferior in at least any of unprocessed film adhesiveness and post-processing film adhesiveness.

1: Steel plate for container 2: Film 3: Part cut out of steel plate 4: Weight 5: Peel length

Claims (5)

Plating having a plating layer composed of at least one layer selected from Ni layer, Sn layer, Ni—Fe alloy layer, Fe—Sn—Ni alloy layer and Fe—Sn alloy layer covering at least a part of the surface of the steel plate A steel plate for containers having a steel plate and a coating disposed on the surface of the plated steel plate on the plating layer side,
The coating contains Ti, Ni and C;
The coating, the deposition amount of Ti in terms of per side of the plated steel sheet is less than 5.0 mg / m ² or more 60.0 mg / m ^2, the adhesion amount of Ni converted per one surface of the plated steel sheet is 0.1 is a ~3.0mg / m ^2,
The steel plate for containers whose mass ratio (C / Ti) of C to Ti in the film is 0.01 to 10. The said coating film is a steel plate for containers of Claim 1 whose adhesion amount of Ti conversion per single side | surface of the said plated steel plate is 10.0-30.0 mg / m < ² >. The steel plate for containers according to claim 1 or 2 whose T value defined by a following formula (2) is 0.50 or less.
T = [Ii (F) -Ib (F)] / Ib (F) (2)
(In Formula (2), Ii (F) represents the F peak count number of fluorescent X-ray analysis of the film, and Ib (F) represents the fluorescence of the film after the container steel plate was immersed in boiling water for 30 minutes. Represents the F peak count of X-ray analysis.)   The steel plate for containers according to any one of claims 1 to 3, wherein the plating layer is a tin plating layer, and the coating includes a Ni-Sn alloy phase.   The steel plate for containers according to any one of claims 1 to 4, wherein C contained in the film is derived from a phenol resin or a phenol compound.