JP2009001853A - Steel sheet for vessel, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel sheet for a vessel having excellent corrosion resistance and can making workability even if being subjected to surface treatment instead of chromating, and to provide a method for producing the same. <P>SOLUTION: The steel sheet for a vessel comprises: a plated steel sheet; and a chemical conversion coating layer formed on the plated steel sheet and including at least two or more kinds of coating films selected from a zirconium coating film containing zirconium of 0.1 to 9 mg/m<SP>2</SP>in a metal zirconium amount, a phosphoric acid coating film containing phosphoric acid of 0.1 to 8 mg/m<SP>2</SP>in a phosphorous amount and a phenol resin coating film containing a phenol resin of 0.05 to 8 mg/m<SP>2</SP>in a carbon amount. Provided that the length of a major axis as a line segment with the maximum length among line segments connecting one end and the other end of an optional particle in the chemical conversion coating layer is denoted as a(nm) and the length of a minor axis as a line segment with the maximum length among the line segments connecting one end and the other end of the particle and also the line segments orthogonal to the major axis is denoted as b(nm), (a+b)/2≤200(nm) is satisfied. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steel plate for containers and a method for producing the same, and particularly relates to a steel plate for containers excellent in corrosion resistance and can manufacturing processability and a method for producing the same.

  As containers for beverages and foods, metal containers made of steel plates such as nickel-plated steel plates, tin-plated steel plates or tin-based alloy-plated steel plates are often used. In such metal containers, it is necessary to paint before or after canning, but in recent years, from the viewpoint of global environmental conservation, waste caused by paints such as waste solvents and exhaust gases such as carbon dioxide gas In order to reduce this, a film is often laminated instead of painting.

  In many cases, the steel plate for containers used for the base of painting and laminate films is protected by chromate using hexavalent chromate or the like in order to ensure adhesion and corrosion resistance between the steel plate and the coating or film. A rust-treated steel plate is used (see, for example, Patent Document 1). Furthermore, these chromate-treated steel sheets are coated with an organic resin on the chromate-treated film for the purpose of imparting organic solvent resistance, fingerprint resistance, scratch resistance, lubricity, etc., if necessary. Is formed.

  However, recently, since hexavalent chromium used for chromate treatment is harmful to the environment, there is a movement to replace the chromate treatment conventionally applied to steel plates for containers. On the other hand, the chromate film formed on the steel sheet surface by chromate treatment has a high degree of corrosion resistance and paint (or film) adhesion. Therefore, when such chromate treatment is not performed, corrosion resistance and paint adhesion Is expected to decline significantly. For this reason, it has been demanded that the surface of the steel plate for containers is subjected to a rust prevention treatment instead of the chromate treatment to form a rust prevention layer having good corrosion resistance and paint adhesion. Various surface treatment methods have been proposed as rust prevention treatment as follows.

  For example, Patent Document 2 discloses a treatment method in which a tin-plated steel sheet is immersed in a chemical conversion treatment solution containing a phosphate ion and a silane coupling agent or is applied and dried.

  Further, for example, Patent Document 3 discloses a surface treatment method for a tin-plated steel sheet by electrolytic reaction using a phosphate compound, and Patent Document 4 discloses a surface by electrolytic reaction using a titanium compound as an aluminum material. A processing method is disclosed.

  Further, for example, Patent Literature 5 and Patent Literature 6 disclose a cathode electrolytic treatment method using a chemical conversion treatment agent containing tin or a tin-based alloy plated steel material containing a zirconium-containing compound and a fluorine-containing compound.

  Further, for example, Patent Document 7 discloses a method of subjecting a tin-plated steel sheet to electrolytic treatment or other chemical conversion treatment using a treatment liquid containing phosphate ions and at least one of titanium ions and zirconium ions. ing.

JP 2000-239855 A Japanese Patent Laid-Open No. 2004-60052 JP 2000-234200 A JP 2002-194589 A JP-A-2005-325402 Japanese Patent Laid-Open No. 2005-23422 JP 54-68734 A

  However, the method described in Patent Document 2 is poor in productivity because it involves a step of immersing in the chemical conversion treatment liquid or applying and drying the chemical conversion treatment liquid, and is equivalent to the case where the chromate treatment is performed. There was a problem that the above satisfactory corrosion resistance could not be obtained. Further, there is a problem that satisfactory corrosion resistance cannot be obtained even by the methods described in Patent Document 3, Patent Document 4, and Patent Document 7.

  Moreover, although the said patent document 5 and patent document 6 have described the point which forms a dense zirconium containing film | membrane in order to obtain satisfactory corrosion resistance, it is essential in order to form such a dense film | membrane. Some of the conditions at the time of the electrolytic treatment considered to be some are not mentioned, and a method for forming a dense film is not specifically disclosed.

  Therefore, the present invention has been made in view of such problems, and its purpose is to produce a steel plate for containers having excellent corrosion resistance and canning processability even when surface treatment is substituted for chromate treatment, and its production. It is to provide a method.

  As a result of intensive research to solve the above-mentioned problems, the present inventors have formed a coating film containing zirconium on the surface of a steel sheet. It has been found that processability can be obtained. Further, the present inventors have found that when a film containing zirconium is formed by low-temperature electrolytic treatment, a film having a dense structure is obtained, and thereby excellent corrosion resistance (particularly, corrosion resistance under the coating film) is obtained. It was.

The present invention has been completed based on such findings, and the gist of the present invention is as follows.
(1) A nickel base or an iron-nickel alloy plating base nickel layer is formed on a steel plate surface, and a part of the tin plating applied on the base nickel layer and a part or all of the base nickel layer are A plated steel sheet in which a tin plating layer containing alloyed island-shaped tin is formed, and formed from one or two or more kinds of zirconium compounds formed on the plated steel sheet, and the amount of metal zirconium is 0.1 mg / m ^2. zirconium film containing zirconium ~9mg / ^{m 2,} 1 kind or phosphate film containing phosphorus acid 0.1~8mg / ^{m 2} in phosphorus content is formed by two or more phosphorus acid compound, and the amount of carbon in has a chemical conversion coating layer comprising at least two or more film selected from a phenolic resin coating containing a phenol resin 0.05~8mg / m ^2, the front The length of the major axis, which is the line segment having the maximum length among the line segments connecting one end and the other end of any particle in the chemical conversion coating layer, is a (nm), and one end and the other end of the particle are (A + b) / 2 ≦ 200 (nm), where b (nm) is the length of the short axis that is the connecting line segment and has the maximum length among the line segments orthogonal to the major axis. A steel plate for containers characterized by that.
(2) the underlying nickel layer contains nickel 5 to 150 mg / ^{m 2} of metal nickel content, the tin-plated layer contains tin 300~3000mg / ^{m 2} by metal tin amount, the tin-plated The steel plate for containers according to (1), wherein the alloying of a part of and a part or all of the base nickel layer is performed by a molten tin treatment.
(3) A tin plating layer formed on at least one surface of the steel plate, and formed from one or more zirconium compounds formed on the tin plating layer and 0.1 mg / m ^{2 to} 9 mg / m in terms of metal zirconium. Zirconium film containing m ² zirconium, phosphoric acid film formed with one or more phosphoric acid compounds and containing 0.1 to 8 mg / m ² phosphoric acid in phosphorus amount, and 0. A chemical conversion coating layer comprising at least two or more types of coatings selected from phenol resin coatings containing from 5 to 8 mg / m ² of phenolic resin, and one end of any particle in the chemical conversion coating layer Of the line segments connecting the other ends, the length of the major axis which is the segment having the maximum length is a (nm), the segment connecting one end and the other end of the particle, and the segment perpendicular to the major axis The longest of When the length of the short diameter is b (nm) which is a line segment having a, (a + b) / 2, characterized in that ≦ a 200 (nm), the container for steel.
(4) the tin plating layer is characterized by containing tin 560mg ^{/ m 2} ~5600mg ^/ m 2 by metal tin content, container steel sheet according to (3).
(5) The steel sheet for containers according to any one of (1) to (4), wherein the chemical conversion coating layer includes at least the zirconium coating.
(6) The steel sheet for containers according to any one of (1) to (4), wherein the chemical conversion film layer includes the zirconium film, the phosphoric acid film, and the phenol resin film.

  According to the steel plate for containers and the manufacturing method thereof of the present invention, it is possible to obtain excellent corrosion resistance and can manufacturing processability even when the steel plate is subjected to surface treatment instead of chromate treatment. Therefore, according to this invention, a metal container can be manufactured using the steel plate for containers which has the outstanding corrosion resistance and can-making processability, without using environmentally harmful hexavalent chromium.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[Configuration of Steel Plate for Containers According to the Present Invention]
The steel plate for containers of the present invention has a base plating layer formed on at least one surface of a steel plate to be an original plate, and a chemical conversion coating layer formed on the base plating layer. As the base plating layer, for example, (A) a nickel plating layer or an iron-nickel alloy plating layer (hereinafter referred to as “base nickel layer”) applied to the steel sheet surface, and an island formed on the base nickel layer A composite plating layer comprising a tin-like tin plating layer and (B) a tin plating layer formed on at least one side of the steel sheet can be formed. Hereinafter, the structure of the steel plate for containers according to the present invention will be described in detail.

(Type of steel sheet)
The steel plate that is the original plate of the steel plate for containers of the present invention is not particularly restricted, and a steel plate that is normally used as a container material can be used. Also, the manufacturing method and material of the original plate are not particularly restricted, and it is manufactured through each process such as hot rolling, pickling, cold rolling, annealing, temper rolling, etc. from a normal slab manufacturing process. Can be used.

  Moreover, the base plating layer is formed on the surface of the steel plate of the present invention as described above. The details of the method for forming the base plating layer will be described later, but are not particularly limited. For example, a known method such as an electroplating method, a vacuum deposition method, or a sputtering method can be used to provide a diffusion layer. You may combine the heat processing for doing. Hereinafter, the base plating layer will be described.

(About composite plating layer of base nickel layer and tin plating layer)
First, as an example of the base plating layer, (A) a composite plating layer including a base nickel layer applied to the steel plate surface and an island-shaped tin plating layer formed on the base nickel layer will be described. The term “underlying nickel layer” as used herein refers to a plating layer containing nickel formed on at least one surface of a steel sheet, and is a metallic nickel plating layer made of metallic nickel, or iron-nickel subjected to iron-nickel alloy plating. It may be an alloy plating layer. Further, the island-shaped tin plating layer is formed by performing tin plating on the base nickel layer and alloying a part or all of the base nickel layer and a part of the tin plating layer by molten tin treatment. It is an alloy plating layer. However, even if tin plating is performed on the plating layer of nickel alone and the molten tin treatment is performed, the above-described island-shaped tin is difficult to form, so an iron-nickel alloy plating layer is used as the underlying nickel layer. It is preferable. Hereinafter, such a nickel plating layer and an island-shaped tin plating layer will be described in detail.

  The base nickel layer made of the above nickel or iron-nickel alloy is formed to ensure corrosion resistance. Since nickel is a highly corrosion-resistant metal, the corrosion resistance of the alloy layer containing iron and tin formed during the molten tin treatment is improved by plating nickel on the surface of the steel sheet as in the case of the steel sheet for containers of the present invention. be able to.

The effect of improving the corrosion resistance of the alloy layer by nickel plating is determined by the amount of nickel to be plated. If the amount of metallic nickel in the underlying nickel layer is 5 mg / m ² or more, the effect of improving the corrosion resistance is manifested. On the other hand, the effect of improving corrosion resistance increases as the amount of nickel in the underlying nickel layer increases. However, if the amount of metallic nickel in the underlying nickel layer exceeds 150 mg / m ² , the effect of improving corrosion resistance is not only saturated, but also nickel. Is an expensive metal, it is economically disadvantageous to plate nickel in an amount exceeding 150 mg / m ² . Therefore, the amount of nickel base nickel layer ^is preferably from ^{5mg / m 2 ~150mg / m 2} .

  In addition, when the base nickel layer is formed by the diffusion plating method, after the nickel plating is performed on the steel sheet surface, a diffusion treatment for forming the diffusion layer is performed in an annealing furnace. A nitriding process may be performed simultaneously with the diffusion process. Even when nitriding is performed, the effect of nickel as the underlying nickel layer and the effect of the nitriding layer in the present invention do not interfere with each other, and these effects can be achieved together.

  As a method of nickel plating and iron-nickel alloy plating, for example, a publicly known method (for example, cathode electrolytic method) generally performed in electroplating can be used.

  After the above nickel plating or iron-nickel plating, tin plating is performed. The “tin plating” in this specification includes not only plating with metallic tin, but also metal tin mixed with irreversible impurities and metal tin added with trace elements. The tin plating method is not particularly limited. For example, a known electroplating method or a method of plating by dipping a steel plate in molten tin may be used.

  The tin plating layer by the above tin plating is formed to ensure corrosion resistance and weldability. Since tin itself has high corrosion resistance, it has excellent corrosion resistance and weldability both as metal tin and as a tin alloy formed by the molten tin treatment (reflow treatment) described below. Can be demonstrated.

  However, in this case, the tin plating layer is formed so as to include island-shaped tin. This is because when the entire surface of the steel plate is plated with tin, the steel plate may be exposed to a melting point (232 ° C.) or more during heat treatment after film lamination or coating, and due to melting of tin or oxidation of tin. This is because the film and paint adhesion cannot be ensured. Therefore, tin is made into islands, and the iron-nickel base corresponding to the sea part is exposed (the part is not melted) to ensure film and paint adhesion.

The excellent corrosion resistance of tin is remarkably improved from the amount of metallic tin of 300 mg / m ² or more, and the degree of improvement in corrosion resistance increases as the tin content increases. Therefore, the amount of metal tin in the tin plating layer containing island-shaped tin is preferably 300 mg / m ² or more. Moreover, since the corrosion resistance improving effect is saturated when the metal tin amount exceeds 3000 mg / m ² , the tin content is preferably 3000 mg / m ² or less from an economical viewpoint.

In addition, tin with low electric resistance is soft and spreads by pressurizing tin between the electrodes at the time of welding, so that a stable energization region can be secured, so that particularly excellent weldability is exhibited. This excellent weldability is exhibited when the amount of metallic tin is 100 mg / m ² or more. Moreover, in the range of the amount of metallic tin exhibiting excellent corrosion resistance, the effect of improving the weldability is never saturated. Therefore, in order to ensure excellent corrosion resistance and weldability, the amount of metal tin is preferably set to 300 mg / m ² or more and 3000 mg / m ² or less.

  After tin plating as described above, molten tin treatment (reflow treatment) is performed. The purpose of the molten tin treatment is to melt tin and form an alloy with an underlying steel plate or an underlying metal (for example, an underlying nickel layer) to form a tin-iron alloy layer or a tin-iron-nickel alloy layer. The purpose is to improve the corrosion resistance of the layer and form an island-shaped tin alloy. This island-shaped tin alloy can be formed by appropriately controlling the molten tin treatment.

  By performing the treatment as described above, for example, a steel plate having a plating structure as shown in FIG. 1A can be manufactured. By the above treatment, an Fe—Ni alloy plating layer 20 made of an Fe—Ni or Sn—Fe—Ni alloy plating layer is formed on the steel plate 10 as a base Ni layer, and the Fe—Ni alloy plating layer 20 is formed on the Fe—Ni alloy plating layer 20. In this case, an Sn plating layer including island-shaped Sn30 is formed. Thus, since Sn is present in an island shape, the coating film without metal Sn and the Fe—Ni or Sn—Fe—Ni alloy plating layer having excellent film adhesion are exposed. On the exposed Sn-plated layer including the Fe-Ni or Sn-Fe-Ni alloy plated layer and the island-shaped Sn30, a chemical conversion treatment film layer 40 to be described later is formed.

(About tin plating layer)
Secondly, as an example of the base plating layer, (B) a tin plating layer (tin plating layer not including island tin) formed on at least one surface of a steel plate will be described.

As described above, tin has excellent workability, weldability, and corrosion resistance. However, in order to obtain sufficient corrosion resistance only by tin plating, the amount of metal tin is preferably set to, for example, 560 mg / m ² or more. Moreover, although corrosion resistance improves, so that the amount of metal tin increases, in the case of tin plating alone, if the amount of metal tin exceeds 5600 mg / m < ² >, the corrosion resistance improvement effect will be saturated. Therefore, from the economical viewpoint, when tin plating is used alone, the amount of metallic tin is preferably 5600 mg / m ² or less. Further, as in the case described above, by performing molten tin treatment after tin plating, it is possible to form iron and an iron-tin alloy layer in the steel sheet, and to impart gloss, and It becomes possible to further improve the corrosion resistance.

  By performing the treatment as described above, for example, a steel plate having a plating structure as shown in FIG. 1B can be manufactured. By the above treatment, the Sn plating layer 35 is formed on the steel plate 10. On the Sn plating layer 35, a chemical conversion treatment film layer 40 to be described later is formed.

  In addition, the composite plating layer or the tin plating layer is preferably formed on both surfaces of the steel plate from the viewpoint of improving the corrosion resistance, but from the viewpoint of reducing the manufacturing cost, the corrosion resistance or the like is provided on one surface of the steel plate. When a surface treatment layer other than the composite plating layer or tin plating layer to be improved is formed, the composite plating layer or tin plating layer may be formed on at least the other surface of the steel plate. In this way, when canning a steel plate for a container having a composite plating layer or a tin plating layer formed on only one side of the steel plate, for example, the surface on which the composite plating layer or the tin plating layer is formed is the inner surface of the container. Processed to be side.

(Measurement method of each component in the composite plating layer or Sn plating layer)
Here, the amount of metallic Ni in the Ni plating layer and the amount of metallic Sn in the Sn plating layer can be measured, for example, by a fluorescent X-ray method. In this case, a calibration curve related to the amount of metal Ni is specified in advance using a sample with a known amount of Ni deposited, and the amount of metal Ni is relatively specified using the calibration curve. Similarly, for a metal Sn amount, a calibration curve related to the metal Sn amount is specified in advance using an Sn adhesion amount sample whose metal Sn amount is known, and the metal Sn amount is relatively specified using the calibration curve.

(About chemical conversion coating layer)
The chemical conversion treatment film layer according to the present invention is formed on the composite plating layer or the Sn plating layer as described above. The chemical conversion treatment film layer includes at least any two of Zr film, phosphoric acid film and phenol resin film. Hereinafter, the chemical conversion film layer according to the present invention will be described in detail.

  When it is formed as a film having at least two or more of the above Zr component, phosphoric acid component and phenol resin component, excellent practical performance can be exhibited. Moreover, especially by making it the film | membrane which has at least Zr component among a phosphoric acid component and a phenol resin component, corrosion resistance and adhesiveness can be further improved among practical performance. Further, like the chemical conversion coating layer according to the present embodiment, the chemical conversion coating layer can be a composite coating in which a Zr component, a phosphoric acid component, and a phenol resin component are combined to exhibit better adhesion. Is possible. In particular, in a range where the amount of the film is small, a film in which three types of Zr film, phosphoric acid film, and phenol resin film are combined is more stably exhibited in order to complement each characteristic.

(Size of particles in the chemical conversion coating layer)
As described above, the steel plate for containers according to the present invention has a chemical conversion coating layer on the base plating layer formed on at least one surface of the steel plate, but the particles contained in the chemical conversion coating layer (for example, When the chemical conversion coating layer is a coating containing a Zr component, the particle size arbitrarily selected for the zirconium compound particles such as zirconium oxide and zirconium phosphate is as shown in FIG. Of the line segments connecting the one end a1 and the other end a2, the length of the line segment having the maximum length (hereinafter referred to as “major axis”) is a (nm), and the line segment connecting the one end b1 and the other end b2 of the particle. When the length of a line segment having the maximum length among the line segments orthogonal to the major axis (hereinafter referred to as “minor axis”) is b (nm), [(a + b) / 2] is 200 ( nm) or less.

  Here, [(a + b) / 2] means the maximum value of the size of arbitrary zirconium compound particles contained in the zirconium film, and the smaller this value, the denser the structure of the zirconium film. It shows that you are doing. Further, a zirconium film having a particle structure in which [(a + b) / 2] is 200 (nm) can be obtained by performing cathodic electrolysis at a low temperature of 10 ° C. to 40 ° C. as will be described in detail later. However, the value of the major axis “a” and the value of the minor axis “b” in the present invention can be measured by observing the surface of the steel plate for containers obtained by electrolytic treatment in this way with a scanning electron microscope (SEM). it can. In addition, it is preferable that the magnification of SEM shall be about 30000 times. Specifically, for example, the major axis “a” and the minor axis “b” of arbitrary particles selected on the SEM photograph of the surface of the steel plate for containers (including particles having the largest size visually) are measured, and the SEM photograph The actual values of the major axis a and the minor axis b can be obtained by converting from the magnification of.

  In the steel plate for containers of the present invention, by forming a chemical conversion coating layer having a dense particle structure such that [(a + b) / 2] is 200 (nm) or less, the corrosion resistance of the steel plate and the coating with the steel plate (laminate) Adhesion with the film) can be improved. Further, preferably, [(a + b) / 2] is a particle having a particle size of 150 (nm) or less, whereby the corrosion resistance of the steel sheet can be further improved. More preferably, [(a + b) / 2] is a particle having a size of 100 (nm) or less, whereby the corrosion resistance after retorting can be improved.

(Zirconium film)
The zirconium film contained in the chemical conversion film of the present invention is formed in order to ensure corrosion resistance and adhesion between the coating and the laminate film (hereinafter referred to as “coating adhesion such as coating”). The zirconium film is formed as a film made of one kind of zirconium compound such as zirconium oxide, zirconium hydroxide, zirconium fluoride, zirconium phosphate or the like, or a composite film made of two or more kinds of zirconium compounds. Such a zirconium film has excellent corrosion resistance and adhesion such as coating. The present inventors consider this reason as follows. That is, regarding the corrosion resistance, the zirconium film is considered to form a three-dimensional crosslinked body by a polymer-like zirconium complex as shown in the following chemical formula 1, and exhibit the corrosion resistance due to the barrier property of the crosslinked body. As for adhesion, the hydroxyl group present in the zirconium film or the hydroxyl group of the phosphate group and the hydroxyl group present on the surface of the metal such as a steel plate undergo dehydration condensation, so that the metal surface and zirconium are bonded via oxygen atoms. It is considered that the adhesiveness is exhibited by covalent bonding with the film.

Specifically, when the adhesion amount of the zirconium film is 0.1 mg / m ² or more in terms of the amount of metal zirconium, a level of corrosion resistance and adhesion such as coating, which are practically satisfactory, are ensured. On the other hand, as the adhesion amount of the zirconium film increases, the effect of improving the adhesion resistance such as corrosion resistance and coating also increases. However, when the adhesion amount of the zirconium film exceeds 9 mg / m ² in terms of the amount of metal zirconium, Because it becomes too thick, it may cause cohesive failure during processing, etc., and the adhesion of the zirconium film itself, the adhesion to the paint, and the adhesion to the film will decrease, and the electrical resistance will increase and the weldability will increase. descend. Moreover, when the amount of zirconium coating deposited exceeds 9 mg / m ^{2 in} terms of the amount of metal zirconium, coating coating unevenness may appear as appearance irregularity, and deposits deposited in the cleaning process after electrolytic treatment Insufficient film may be washed away (peeled off). Therefore, in the container steel sheet of the present invention, the adhesion amount of the zirconium film is required to be a 0.1mg ^{/ m 2} ~9mg ^/ m 2 of metal zirconium content. Preferably the coating weight of zirconium coating is ^1mg / ^{m 2 ~8mg} / m 2 of metal zirconium content. The attached amount of zirconium film by the range of ^{1mg / m 2 ~8mg / m 2} , with the corrosion resistance after the retort can be secured, it is possible to reduce the fine adhesion unevenness.

(Phosphate film)
Moreover, the phosphoric acid film | membrane contained in the said chemical conversion treatment film layer is formed in order to ensure adhesiveness, such as corrosion resistance and coating. The phosphate film is formed by reacting with the base (steel plate, nickel plating layer, tin plating layer, zirconium film, phenol resin film), iron phosphate, nickel phosphate, tin phosphate, zirconium phosphate, phenol phosphate Etc., or a composite film made of two or more of these phosphate compounds. Although such a phosphate film has excellent corrosion resistance and adhesion such as coating, the present inventors have found that this is because the phosphate ions are complexed with various metal ions, and the three-dimensional as described above. Forming a cross-linked coating, and even if metal ions such as iron and nickel elute (the first stage of corrosion), forming a phosphate compound makes the metal ions insoluble and reduces further corrosion It is thought to be due to having an effect.

Specifically, when the adhesion amount of the phosphoric acid film is 0.1 mg / m ² or more in terms of the phosphorus amount, corrosion resistance and adhesion such as coating that are practically satisfactory are ensured. On the other hand, as the adhesion amount of the phosphoric acid film increases, the effect of improving the adhesion resistance such as corrosion resistance and coating is also increased. However, if the adhesion amount of the phosphoric acid film exceeds 8 mg / m ² in terms of the amount of phosphorous, Since the film becomes too thick, it may cause cohesive failure during processing, etc., and the adhesion of the phosphoric acid film itself, adhesion to the paint, and adhesion to the film will decrease, and electrical resistance will increase. Weldability decreases. Moreover, if the amount of phosphoric acid coating deposited exceeds 8 mg / m ² in terms of phosphorus, the coating unevenness may appear as uneven appearance, and deposits deposited in the cleaning process after electrolytic treatment Insufficient film may be washed away (peeled off). Therefore, in the container steel sheet of the present invention, adhesion of the phosphoric acid coating should be in the amount of phosphorus and ^{0.1mg / m 2 ~8mg / m 2} . Preferably, deposition amount of phosphate film is ^1mg / ^{m 2 ~6mg} / m 2 in phosphorus content. By the deposition amount of phosphate film in the range of ^{1mg / m 2 ~6mg / m 2} , with corrosion resistance can be secured after the retort, it is possible to reduce the fine adhesion unevenness.

(Phenolic resin film)
Moreover, the said chemical conversion treatment film layer may contain the phenol resin film containing a phenol resin component as mentioned above.

  The phenol resin film is formed to ensure adhesion such as painting. Since the phenol resin itself is an organic substance, it has very good adhesion to paints and laminate films made from organic substances.

  When the surface treatment layer undergoes processing that greatly deforms, the surface treatment layer itself may be coherently destroyed by the processing, and adhesion may deteriorate, but the phenol resin contains a Zr film or a phosphate film Has the effect of significantly improving the work adhesion of these films.

Specifically, when the adhesion amount of the phenolic resin film is 0.05 mg / m ² or more in terms of the carbon amount, adhesion such as coating that is practically satisfactory is ensured. On the other hand, as the adhesion amount of the phenol resin film increases, the effect of improving the adhesion such as painting also increases. However, when the adhesion amount of the phenol resin film exceeds 8 mg / m ² in terms of carbon amount, the phenol resin film Since it becomes too thick, while the adhesiveness of phenol resin film itself falls, an electrical resistance rises and weldability falls. In addition, when the amount of phenol resin film deposited exceeds 8 mg / m ² in terms of carbon, the film adhesion unevenness may appear as appearance irregularities, and the deposits deposited in the cleaning process after electrolytic treatment Insufficient film may be washed away (peeled off). Therefore, in the container steel sheet of the present invention, the adhesion amount of the phenol resin coating, it is necessary to 0.05mg ^{/ m 2} ~8mg ^/ m 2 in carbon content. Preferably the coating weight of the phenolic resin coating is 0.1mg ^{/ m 2} ~6mg ^/ m 2 in carbon content. By adhering amount of the phenol resin coating the range of ^{0.1mg / m 2 ~6mg / m 2} , it is possible to reduce the fine adhesion unevenness (yellow due to adhesion odd), and sufficiently the phenolic additive effect Can be demonstrated.

(Measurement method of content of each component in chemical conversion coating layer)
The amount of metallic zirconium and the amount of phosphorus contained in the chemical conversion coating layer according to the present invention can be measured by, for example, a quantitative analysis method such as fluorescent X-ray analysis. The amount of carbon in the chemical conversion coating layer can be determined, for example, by subtracting the amount of carbon contained in the steel sheet as the background from the value measured by the total carbon amount measurement method by gas chromatography.

  As described above, in the steel plate for containers according to the present invention, a chemical conversion treatment film layer containing at least two or more of a zirconium film, a phosphoric acid film, and a phenol resin film is formed on at least one surface of the above-described plated steel sheet. By this, it can have the outstanding corrosion resistance and can manufacturing workability (especially adhesion, such as coating, drawing ironing workability, weldability, etc.). Moreover, when the said chemical conversion treatment film layer contains a zirconium film at least, corrosion resistance, adhesion, such as coating, can further be improved. Furthermore, when the said chemical conversion treatment film layer contains all of a zirconium membrane | film | coat, a phosphoric acid membrane | film | coat, and a phenol resin membrane | film | coat, adhesiveness, such as coating, can be improved notably. In addition, corrosion resistance can further be improved by forming a nickel plating layer between a zirconium membrane | film | coat and a steel plate.

[Method for producing steel plate for containers according to the present invention]
As mentioned above, although the structure of the steel plate for containers which concerns on this invention was demonstrated, next, the manufacturing method for obtaining this steel plate for containers is demonstrated in detail.

  First, prior to explaining the method for forming a chemical conversion coating film layer according to the present invention, a method for a molten tin treatment performed after tin plating is applied to a steel plate or a plated steel plate to which nickel-based plating has been applied will be briefly described. Explained.

  The molten tin treatment is also referred to as reflow treatment, and is performed in order to melt the Sn on the surface and raise the surface gloss by raising the temperature to 232 ° C. or higher, which is the melting point of Sn, after Sn plating. Also, by performing molten tin treatment, the surface Sn is melted and alloyed with a base steel plate or a base metal to form a Sn—Fe alloy layer or a Sn—Fe—Ni alloy layer. Improve corrosion resistance. Moreover, island-shaped Sn can be formed by appropriately controlling the molten tin treatment. As a result, it is possible to manufacture a steel sheet having a plating structure in which an Fe—Ni alloy plating layer or an Fe—Ni—Sn alloy plating layer having excellent adhesion to a paint and a film free of metal Sn is exposed.

  The molten tin treatment is heated to 232 ° C. or higher, preferably about 240 ° C., which is the melting point of Sn in a few seconds (for example, within 10 seconds), and as uniformly as possible to about 240 ° C. It is performed by rapidly cooling to around room temperature (for example, about 50 degrees).

  The method for producing a steel plate for containers according to the present invention includes performing low-temperature cathodic electrolysis treatment on a plated steel plate on which a base plating layer as described above is formed on at least one surface of the steel plate. A chemical conversion treatment film layer is formed. As a method of forming such a chemical conversion treatment film, for example, a method of immersing a steel sheet in an acidic solution in which zirconium ions, phosphate ions, low-molecular phenol resins, or the like are dissolved, or such an acidic solution is used. There is a method of performing cathodic electrolysis.

  Here, in the treatment method by immersion, the steel sheet as the base of the chemical conversion film layer and the plating layer formed on the steel sheet surface are etched to form various films. Since the amount of adhesion becomes non-uniform and the processing time required for forming the chemical conversion coating layer becomes long, this is industrially disadvantageous.

  On the other hand, in the method using cathodic electrolysis, a uniform film is formed for several seconds by combining surface cleaning by forced charge transfer and hydrogen generation at the steel sheet interface, and adhesion promoting effect by increasing the hydrogen ion concentration (pH). Since it can be formed by short-time treatment (which may actually be about 0.01 seconds), it is extremely advantageous industrially. Therefore, in the manufacturing method of the steel plate for containers of this invention, the chemical conversion treatment film layer is formed by the cathodic electrolytic treatment.

(Components of chemical conversion solution used for cathodic electrolysis)
In order to form the chemical conversion treatment film layer by cathodic electrolytic treatment, depending on the type of film to be formed among the zirconium film, phosphoric acid film, and phenol resin film contained in the chemical conversion treatment film layer, the electrolytic treatment is performed. It is necessary to determine the components in the chemical conversion solution to be used. Specifically, when it is desired to form a chemical conversion coating layer containing only a zirconium coating, a chemical conversion treatment solution containing zirconium ions in an acidic solution of 100 ppm to 7500 ppm may be used. When it is desired to form a chemical conversion coating layer including a coating, it is sufficient to use a chemical conversion processing solution containing 100 ppm to 7500 ppm of zirconium ions and 50 ppm to 5000 ppm of phosphate ions in an acidic solution. When it is desired to form a chemical conversion coating layer including an acid coating and a phenolic resin coating, the chemical conversion solution is composed of an acidic solution containing 100 ppm to 7500 ppm of zirconium ions, 50 ppm to 5000 ppm of phosphate ions, and a mass average molecular weight of about 5000. A low molecular weight fe The Lumpur resin may be used that is contained 10Ppm～1500ppm.

  Tannic acid may be added to the acidic solution used as the chemical conversion solution for the cathodic electrolysis. By adding tannic acid to the treatment liquid in this way, tannic acid binds to iron atoms on the steel sheet surface, and a film of iron tannate is formed on the steel sheet surface, improving rust resistance and adhesion. it can. Therefore, when using the steel plate for containers of the present invention for applications where rust resistance and adhesion are important, the chemical conversion treatment film layer is formed in an acidic solution to which tannic acid is added, if necessary. Also good.

  Moreover, as a solvent of the acidic solution used for formation of the chemical conversion film layer according to the present invention, for example, distilled water or the like can be used, but the solvent of the acidic solution is not limited thereto and dissolves. It can be appropriately selected depending on the material, the forming method, the formation conditions of the chemical conversion coating layer, and the like. However, it is preferable to use distilled water from the viewpoint of industrial productivity, cost, and environment based on the stable adhesion amount of each component.

Moreover, in the chemical conversion treatment solution used for forming the chemical conversion treatment layer of the present invention, for example, a Zr complex such as H ₂ ZrF ₆ can be used as a Zr supply source. Zr in the Zr complex as described above is present in the chemical conversion solution as Zr ⁴⁺ by a hydrolysis reaction due to an increase in pH at the cathode electrode interface. Such Zr ions react more rapidly in the chemical conversion solution and become compounds such as ZrO ₂ , Zr ₃ (PO ₄ ) ₄ , Zr (HPO ₃ ) _2, etc., and become hydroxyl groups (− OH) and a dehydration condensation reaction can form a Zr film. Moreover, when adding a phenol resin to a chemical conversion liquid, as shown to following Chemical formula 2, you may make a phenol resin amino acid modification | denaturation, and you may give water solubility, for example. Furthermore, in order to adjust the pH of the chemical conversion treatment solution, for example, nitric acid, ammonia or the like may be added.

(Cathode electrolysis treatment conditions)
Cathodic electrolytic treatment for forming the chemical conversion treatment film layer of the present invention uses, for example, a low-temperature electrolytic treatment apparatus 100 shown in FIG. Performed (low temperature cathodic electrolysis). As the low-temperature electrolytic processing apparatus 100 according to an embodiment of the present invention, for example, two anode electrodes 106 are opposed to each other in a container 104 containing an electrolytic processing solution 102 containing about 10 to 40 ° C. containing predetermined components. It is possible to use a structure in which the anode electrodes 106 are connected to the positive electrode 112 side of the rectifier 110. When performing low-temperature electrolytic treatment, a steel plate (electrolytically treated steel plate) 108 to be treated is disposed between the two anode electrodes 106, and the electrolytically treated steel plate is electrically connected to the negative electrode 114 side of the rectifier 110. By keeping the electrolytic density in the above range by the rectifier 110, it is possible to manufacture the container steel plate according to the present embodiment. Thus, by performing cathodic electrolysis at a low temperature of 40 ° C. or less, for example, as shown in the left diagram of FIG. 3, the major axis a (nm) and minor axis of any particle in the formed chemical conversion coating layer. It is possible to form a dense and uniform film structure formed by very fine particles such that the average value [(a + b) / 2] of b (nm) is 200 nm or less. Further, when the temperature of the chemical conversion treatment liquid is less than 10 ° C., not only the film formation efficiency is poor, but also cooling is necessary when the outside air temperature is high such as in summer, which is not economical. On the other hand, when the temperature of the chemical conversion treatment liquid exceeds 40 ° C., for example, as shown in the right diagram of FIG. 3, the formed film structure tends to be non-uniform, and film defects, film cracks, microcracks, etc. are generated and dense. Since film formation becomes difficult, it may be a starting point for corrosion and the like.

  Further, the low-temperature electrolytic treatment apparatus according to the present embodiment is not limited to the batch processing apparatus as shown in FIG. 4, and for example, a low-temperature electrolytic treatment apparatus devised so that continuous operation is possible is used. Is also possible.

The cathodic electrolysis treatment is preferably performed at an electrolysis current density of 0.05 A / dm ^{2 to} 50 A / dm ² . When the electrolysis current density is less than 0.05 A / dm ² , the amount of coating is reduced, it is difficult to form a stable coating, and a long electrolytic treatment time may be required. In some cases, the corrosion resistance, paint adhesion, and the like may decrease. On the other hand, when the electrolysis current density exceeds 50 A / dm ² , the coating amount exceeds the required amount and becomes saturated and becomes saturated. Depending on the case, washing with water after electrolytic conversion treatment, etc. It is not economical, for example, a film with insufficient adhesion is washed away (peeled off) in the cleaning process, and the temperature of the chemical conversion treatment liquid is increased during the electrolytic treatment, and the temperature conditions of the above-described low-temperature cathode electrolytic treatment are maintained. In order to do so, the chemical conversion solution may need to be cooled.

  Moreover, it is preferable that the said cathodic electrolysis process is performed in 0.01 to 5 second energization time. When the energization time is less than 0.01 seconds, the amount of film adhesion is reduced, and it is difficult to form a stable film, and the corrosion resistance and paint adhesion may be reduced. On the other hand, when the energization time exceeds 5 seconds, the coating amount exceeds the required amount, and the amount of deposition becomes saturated. In some cases, the coating is deposited in a washing process such as water washing after the electrolytic conversion treatment. Insufficient coating is washed away (peeled), which is not economical, and causes an increase in the temperature of the chemical conversion treatment solution, so that the chemical conversion treatment solution is cooled in order to maintain the temperature conditions of the low-temperature cathodic electrolysis described above. It may be necessary to perform an extra process.

By performing cathodic electrolysis with the above-described electrolytic current density and energization time, a coating with an appropriate amount of adhesion can be formed on the steel sheet surface. Thus, for example, chemical conversion if it contains zirconium ion in the concentration range mentioned above in the treatment solution, it is possible to form a coating weight of zirconium coating of 0.1mg ^/ m ² ~9mg / m 2 by metal zirconium content (The same applies to phosphoric acid films and phenol resin films).

  Next, the present invention will be described more specifically using examples and comparative examples, but the present invention is not limited to the following examples.

<Production of steel plate>
First, the steel plate which forms a chemical conversion treatment film layer by the method shown below was produced.
(A1: Manufacturing method of steel plate having Ni plating layer and Sn plating layer)
After cold rolling, the steel substrate (steel plate) having an annealed and regulated thickness of 0.17 to 0.23 mm is degreased and pickled, and then subjected to Fe-Ni alloy plating using a sulfuric acid-hydrochloric acid bath. Then, Sn plating was performed using a ferrostan bath, and then a molten tin treatment was performed to prepare a Ni and Sn plated steel sheet having a Sn alloy layer.

(A2: Manufacturing method of steel sheet having Sn plating layer)
After cold rolling, the steel substrate (steel plate) having a thickness of 0.17 to 0.23 mm that has been annealed and adjusted is degreased and pickled, then Sn-plated using a ferrostan bath, and then melted and melted. A composite plated steel sheet having a Sn alloy layer was prepared by performing a tin treatment.

(A3: Method for producing a steel sheet obtained by further alloying the Sn plating layer of A1)
After cold rolling, the steel substrate (steel plate) having an annealed and regulated thickness of 0.17 to 0.23 mm is degreased and pickled, then Ni-plated using a watt bath, and Ni is annealed. A diffusion layer was formed, and after degreasing and pickling, Sn plating was performed using a ferrostan bath, and then molten tin treatment was performed to prepare a Ni and Sn plated steel sheet having a Sn alloy layer.

  In addition, about said (A1)-(A3), the minimum value of the adhesion amount of metal nickel and metal tin, the optimal value, and the maximum value are as Table 1 below, respectively.

<Formation of chemical conversion treatment film layer>
Next, (B1) Zr film, phosphoric acid film and phenolic resin film, (B2) phosphoric acid on the surface (both sides) of the steel sheet produced by the above-described methods (A1) to (A3) by the following method A film and a phenol resin film, (B3) Zr film and phosphoric acid film, (B4) Zr film and phenol resin film were formed. Furthermore, tannic acid was added to the electrolytic treatment solution to form a chemical conversion treatment film layer composed of a Zr film and a phosphoric acid film (B5).

  (B1) A plating-less steel sheet or Ni-plated steel sheet prepared by the method (A1) or (A2, A3) is immersed in a treatment solution in which Zr fluoride, phosphoric acid, and a phenol resin are dissolved in distilled water. After the cathodic electrolysis treatment, it was washed with water and dried.

  (B2) Cathodic electrolytic treatment was performed by immersing the plating-less steel sheet or Ni-plated steel sheet prepared by the method (A1) or (A2, A3) in a treatment solution in which phosphoric acid and a phenol resin were dissolved in distilled water. Then, it was washed with water and dried.

  (B3) Cathodic electrolytic treatment by immersing the plating-free steel sheet or Ni-plated steel sheet prepared by the method (A1) or (A2, A3) in a treatment solution in which Zr fluoride and phosphoric acid are dissolved in distilled water Then, it was washed with water and dried.

  (B4) Cathodic electrolytic treatment by immersing the plating-free steel sheet or Ni-plated steel sheet prepared by the method (A1) or (A2, A3) in a treatment solution in which Zr fluoride and a phenol resin are dissolved in distilled water. Then, it was washed with water and dried.

  (B5) A plating-less steel sheet or Ni-plated steel sheet prepared by the method (A1) or (A2, A3) is immersed in a treatment solution in which Zr fluoride, phosphoric acid and tannic acid are dissolved in distilled water. After the cathodic electrolysis treatment, it was washed with water and dried.

  In addition, the component of the chemical conversion liquid used by said (B1)-(B5) is as Table 2 below, respectively.

  About each steel plate for containers produced by the above-mentioned method, the metal Zr amount and the P amount in the chemical conversion coating layer were measured by a quantitative analysis method using fluorescent X-rays. The amount of carbon in the chemical conversion coating layer was determined by subtracting the amount of carbon contained in the steel sheet as the background from the value measured by the total carbon content measurement method by gas chromatography.

<Performance evaluation method>
Next, each container steel plate produced by the above-mentioned method is used as a test material, and the test materials of these examples and comparative examples are processability, weldability, film adhesion, paint adhesion, corrosion resistance, rust resistance and appearance. Each performance of was evaluated. The specific evaluation method and evaluation criteria will be described below.

(1) Corrosion resistance After applying an epoxy-phenol resin to one surface of each of the test materials of Examples and Comparative Examples, baking was carried out by holding at 200 ° C. for 30 minutes. A test solution comprising a mixed solution of citric acid (1.5% by mass) -salt (1.5% by mass) obtained by adding a crosscut having a depth reaching the steel substrate to the portion coated with the resin. The film was immersed for 72 hours at 45 ° C., washed and dried, and then subjected to a tape peeling test. Under the coating film (epoxy-phenol resin film) in the cross-cut portion, the corrosion state of the flat plate portion. It was evaluated with. As a result, the case where no corrosion was observed under the coating film was ◎, the case where slight corrosion was observed under the coating film to the extent that there was no practical problem, and the minute corrosion was recognized under the coating film. The case where a slight corrosion was observed on the flat plate part or the case where a significant corrosion was observed under the coating film or the case where the plate part was found to be corrosive was rated as x.

(2) Rust resistance After applying an epoxy-phenolic resin to one surface of each test material of Examples and Comparative Examples, baking was performed by holding at 200 ° C. for 30 minutes. A test solution comprising a mixed solution of citric acid (1.5% by mass) -salt (1.5% by mass) obtained by adding a crosscut having a depth reaching the steel substrate to the portion coated with the resin. The film was immersed for 72 hours at 45 ° C., washed and dried, and then subjected to a tape peeling test. Under the coating film (epoxy-phenol resin film) in the cross-cut portion, the corrosion state of the flat plate portion. It was evaluated with. As a result, the case where no corrosion was observed under the coating film was ◎, the case where slight corrosion was observed under the coating film to the extent that there was no practical problem, and the minute corrosion was recognized under the coating film. The case where a slight corrosion was observed on the flat plate part or the case where a significant corrosion was observed under the coating film or the case where the plate part was found to be corrosive was rated as x.

(3) Workability After laminating a PET film having a thickness of 20 μm on both surfaces of each test material of the examples and comparative examples at 200 ° C., a can-making process by drawing and ironing is performed in stages, and the molding is performed. It was evaluated by sex. As a result, it was found that there was no breakage or generation of wrinkles and the moldability was very good. X.

(4) Weldability The minimum that can obtain sufficient welding strength by welding each test material of the example and the comparative example by using a wire seam welding machine and changing the current at a welding wire speed of 80 m / min. The evaluation was comprehensively based on the width of an appropriate current range consisting of a current value (4000 A or less) and a maximum current value (5000 A or more) at which welding defects such as dust and welding spatter start to stand out. As a result, the case where the weldability was wider than that of the current value range and the weldability was extremely good was evaluated as ◯, the case where the weldability was narrower than the above range, and the case where welding was impossible.

(5) Paint adhesion After applying an epoxy-phenolic resin to one surface of each test material of Examples and Comparative Examples, baking was carried out by holding at 200 ° C. for 30 minutes. And after forming notches with a depth reaching the steel substrate in a grid pattern at intervals of 1 mm in the part where the resin was applied, a cross-cut peel test was performed in which an adhesive tape was applied to the part and peeled off. . As a result, ◎ indicates that there was no peeling at all, ○ indicates that there was a slight peeling that does not cause a problem in practice, △ indicates that there was a slight peeling, and × indicates that most of the peeling has occurred.

(6) Film adhesion After laminating a PET film having a thickness of 20 μm on both surfaces of each of the test materials of Examples and Comparative Examples at 200 ° C., a squeezing and ironing process was performed to produce a can body. On the other hand, the retort process for 30 minutes was performed at 125 degreeC, and the peeling condition of the film in that case evaluated. As a result, ◎ indicates that there was no peeling, ◯ indicates that there was a slight peeling with no practical problem, △ indicates that there was a slight peeling, and most of the peeling occurred. The thing was made into x.

(7) Appearance Each test material of Examples and Comparative Examples was visually observed and evaluated in terms of unevenness generated in the Zr film, phosphoric acid film and phenol resin film. As a result, it was ◎ that there was no unevenness at all, ◯ that had slight unevenness to the extent that there was no practical problem, △ that had slight unevenness, and × that had extremely unevenness × It was.

(8) Island-like Sn formation situation The surface of the island-like Sn formation situation when Sn plating was performed after Ni-based plating was observed with an optical microscope, and the island-like Sn situation was evaluated. The case where islands were formed as a whole was indicated by ◯, the case where there were portions where no islands were formed was indicated by Δ, and the case where islands were not formed were indicated by ×.

  The above results are shown in Tables 3 and 4 below. In addition, in the following Table 3 and Table 4, the amount of Ni plating layer and the amount of adhesion of each film in each test material of Examples and Comparative Examples are also shown. Moreover, the Ni plating amount shown in the following Table 3 and Table 4 is a value obtained by a fluorescent X-ray measurement method, and the adhesion amount of each film is about the Zr film amount (Zr amount) and the phosphoric acid film amount (P amount). Is a value obtained by quantitative analysis with fluorescent X-rays, and the amount of phenol resin film (C amount) is obtained by a total carbon amount measurement method by gas chromatography (the amount of C contained in steel is subtracted as background). Value.

  Further, the treated surface is observed with an SEM, and the length of the major axis which is the line segment having the maximum length among the line segments connecting one end and the other end of an arbitrary particle is represented by a (nm), and one end of the particle and the other The length of the minor axis that is the line segment connecting the ends and having the maximum length among the line segments orthogonal to the major axis is b (nm), and the particles in the film included in this example As the particle diameter (nm), a value of {(a + b) / 2} (nm) was obtained.

  As shown in Table 3 above, with respect to Examples 1 to 52 in which the Zr adhesion amount, the P adhesion amount, the C adhesion amount, and the particle diameter are within the scope of the present invention, the evaluations of (1) to (7) Also showed good results. In Examples 1 to 20 and 41 to 52 in which the island-shaped Sn plating layer was formed, the island-shaped Sn was entirely formed.

  On the other hand, as shown in Table 4 above, the amount of Zr adhesion, the amount of P adhesion, the amount of C adhesion or the particle diameter is outside the scope of the present invention (Comparative Examples 1, 2, 6 to 15), or the Zr film, In the case where only one of the phosphoric acid film and the phenol resin film was included (Comparative Examples 3 to 5), the evaluations of the above (1) to (7) were inferior to those of Examples 1 to 52. In particular, it was suggested that Comparative Examples 3 to 5 containing only one of a Zr film, a phosphoric acid film, and a phenol resin film are remarkably inferior in corrosion resistance and adhesion.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not controlled by this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

It is explanatory drawing for demonstrating the 1st example of the base plating layer which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the 2nd example of the base plating layer which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the measuring method of the particle | grains which concern on the same embodiment. It is a SEM photograph for demonstrating the state of the zirconium membrane | film | coat manufactured by the low-temperature electrolytic process which concerns on the same embodiment, and the zirconium film | membrane manufactured without performing the low-temperature electrolytic process which concerns on the same embodiment. It is explanatory drawing for demonstrating the low temperature electrolysis processing apparatus which concerns on the same embodiment.

Explanation of symbols

10 Steel plate 20 Fe-Ni alloy plating layer 30 Island-like Sn
35 Sn plating layer 40 Chemical conversion treatment film layer 100 Low-temperature electrolytic treatment apparatus 102 Electrolytic treatment liquid 104 Container 106 Anode electrode 108 Electrolytically treated steel plate 110 Rectifier 112 Positive electrode 114 Negative electrode

Claims (6)

A base nickel layer formed by nickel plating or iron-nickel alloy plating is formed on the steel sheet surface, and a part of the tin plating applied on the base nickel layer and a part or all of the base nickel layer are alloyed. A plated steel sheet on which a tin plating layer containing tin-like islands is formed;
Wherein formed on the plated steel sheet, one or more formed from a zirconium compound metal zirconium content of zirconium containing zirconium 0.1mg ^/ m ² ~9mg / m 2 film, one or more A phosphoric acid film formed with a phosphoric acid compound and containing 0.1 to 8 mg / m ² of phosphoric acid in terms of phosphorus and a phenolic resin film containing 0.05 to 8 mg / m ² of phenolic resin in terms of carbon A chemical conversion coating layer comprising at least two types of coatings formed;
Have
The length of the major axis, which is the line segment having the maximum length among the line segments connecting one end and the other end of any particle in the chemical conversion coating layer, is a (nm), and the one end and the other end of the particle (B + nm) / 2 ≦ 200 (nm), where b (nm) is the length of the minor axis that is the line segment connecting the two and perpendicular to the major axis. A steel plate for containers, characterized by being. The base nickel layer contains 5 to 150 mg / m ² of nickel in terms of metallic nickel,
The tin plating layer contains 300 to 3000 mg / m ² of tin in terms of metal tin,
2. The steel plate for containers according to claim 1, wherein the alloying of a part of the tin plating and a part or all of the base nickel layer is performed by a molten tin treatment. A tin plating layer formed on at least one side of the steel plate;
Wherein formed on the tin-plating layer, one or more formed from a zirconium compound metal zirconium content of zirconium containing zirconium 0.1mg ^/ m ² ~9mg / m 2 film, one or more A phosphoric acid film containing 0.1 to 8 mg / m ² of phosphoric acid and a phenolic resin film containing 0.05 to 8 mg / m ² of phenolic resin A chemical conversion coating layer containing at least two or more selected coatings;
Have
The length of the major axis, which is the line segment having the maximum length among the line segments connecting one end and the other end of any particle in the chemical conversion coating layer, is a (nm), and the one end and the other end of the particle (B + nm) / 2 ≦ 200 (nm), where b (nm) is the length of the minor axis that is the line segment connecting the two and perpendicular to the major axis. A steel plate for containers, characterized by being. The tin plating layer is characterized by containing tin 560mg ^{/ m 2} ~5600mg ^/ m 2 by metal tin content, container steel sheet according to claim 3.   The said chemical conversion treatment film layer contains the said zirconium film at least, The steel plate for containers in any one of Claims 1-4 characterized by the above-mentioned.   The said chemical conversion treatment film layer contains the said zirconium film, the said phosphoric acid film, and the said phenol resin film, The steel plate for containers in any one of Claims 1-4 characterized by the above-mentioned.