JP2696729B2 - Manufacturing method of surface treated steel sheet for organic resin coating with excellent processing adhesion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a surface-treated steel sheet for coating with an organic resin, which has excellent workability. More specifically, the present invention relates to a method for producing a surface-treated steel sheet for coating with an organic resin, which is suitable for a material for cans requiring strict processing adhesion, such as a redraw-drawn can and a thinned deep-drawn can which is subjected to stretching after drawing.

[0002]

2. Description of the Related Art A metal can used for a food can or a beverage can is a three-piece can consisting of a can body, a can lid, and a bottom lid, a can body in which the can body and the bottom lid are integrated, and a can lid. It is roughly divided into two-piece cans consisting of two parts. Further, three-piece cans are classified into solder cans, adhesive cans and welding cans according to the method of joining the can bodies. For two-piece cans, drawn cans, drawn redrawn cans (DRD cans), drawn and ironed cans (DI
Cans) and recently developed drawing, and then into thinned deep-drawn cans that are stretched. Except for DI cans, which are painted after processing, these materials for metal cans are mainly made of tinplate and electrolytic chromic acid-treated steel plate (Tin Free Steel, hereinafter abbreviated as TFS) which has been coated once or several times. Used. Although the material for the can used varies depending on the method for making the can and its use, etc., it is used taking advantage of the characteristics of each material for the can. For applications requiring tight adhesion of the organic resin coating layer after severe processing, which is the object of the present invention, TFS having excellent processing adhesion of the organic resin coating layer is used. For shallow drawn cans with a relatively small drawing ratio, ordinary tinplate is used, in which tin plating is applied and then electrolytically treated in a sodium bichromate solution to form a chromium hydrated oxide layer on the surface of the tin layer. ing. In this normal tinning, if the working degree is further increased, the coating film may be peeled off, and in order to improve the working adhesion of the coating film, the lower layer is formed of metallic chromium and the upper layer is formed of chromium water on the plated tin layer. A method for forming a two-layer film of a hydrated oxide, a so-called TFS-treated film, is disclosed in Japanese Patent Application Laid-Open No. 60-34637 and Japanese Patent Publication No. 60-3544.
No. 0 and Japanese Patent Publication No. 60-39159. Tinplates obtained by these methods certainly have better processing adhesion of the coating film than normal tinplates, but two layers of an appropriate amount of metallic chromium and chromium hydrated oxide are deposited on the plated tin layer. In order to form a film, strict control is required such as the amount of an auxiliary in a chromic acid bath and electrolysis conditions. Further, the tinplate obtained has a black tint, and strict control is required for the toning of the printing ink used for printing on the outer surface of the can. Further, this tinting is a DRD can requiring excellent processing adhesion of the organic resin coating layer which is the object of the present invention,
When used for thinned deep drawn cans, the organic resin coating layer may peel off. The tinplate formed with the TFS-treated film, when heated to cure the coating, has a remarkably fast growth of the iron-tin alloy, particularly when the tin plating amount is small.
The coating film easily peels off due to severe processing. Therefore, these cans cannot be continuously produced in a stable state. The tinplate formed with the TFS-treated film as described above has the above-mentioned disadvantages.

Recently, a method of using a metal plate obtained by laminating a thermoplastic resin film such as a polyester resin film on a TFS or tinplate instead of coating for a thin-walled deep-drawing can requiring strict processing adhesion and processing corrosion resistance is required. (Japanese Unexamined Patent Application Publication No.
269647, JP-A-2-263523) have been proposed. TFS laminated polyester resin film
When used for thinned drawn cans, it is necessary to improve the workability of the polyester resin film itself to prevent the laminated polyester resin film from peeling off or cracking in this film due to severe processing JP-A-64-22530, JP-A-1-24
9331 and JP-A-2-57339 have been proposed. However, the process of laminating these polyester resin films on TFS, or drawing,
Foreign matter such as dust may be mixed in the process of redrawing, etc., and starting from the part where the foreign matter is mixed,
Fine cracks may be present in the polyester resin film laminated during drawing and redrawing. For example, when the thinned deep drawn can is filled with a carbonated beverage or a sports beverage and stored at room temperature for about one month, pitting may occur from the minute cracks. Therefore, there is a disadvantage that these steps must be strictly controlled.

As a method of laminating a polyester resin film on a tin plate, a method of temporarily bonding the polyester resin film at a temperature lower than the melting point of tin and heating the polyester resin film to a temperature higher than the melting point of tin (Japanese Patent Publication No. 61-1986). 3676), a method of laminating a polyester resin film on a metal plate such as TFS or tinplate heated to a temperature not lower than the melting point of the polyester resin and quenching (Japanese Patent Publication No. 60-47103), the melting point of the copolymerized polyester resin ± 50. TF heated to ℃
A method of laminating a copolymerized polyester resin film coated with a specific adhesive on a metal plate such as S, tinplate, etc.
-249331) and the like. The polyester resin film-laminated tin-plated steel sheets obtained by these disclosed methods are inferior in processing adhesion of the polyester resin film, severe processing adhesion, as compared with the polyester resin film-laminated TFS obtained by the same method. It is impossible to use it for thin-walled deep-drawing cans that require processing corrosion resistance. Various methods have been studied in order to develop a material for cans that has excellent processing adhesion to an organic resin layer of TFS and excellent processing corrosion resistance of tinplate. As an example, using a tin plating solution of a specific composition with a polyester resin film, there are many steel plate exposed parts on the steel plate surface,
Surface-treated steel sheet in which a tin-plated coating of chromium hydrated oxide is formed on the upper layer and chromium metal oxide is formed on the lower layer, so-called tinplate and TF
Method of laminating on S surface treated steel sheet (Japanese Patent Application No. Hei 2-
No. 33811) has been proposed. When the polyester laminated film steel sheet obtained by this method is used for a thinning deep drawing can, the laminated polyester resin film does not peel off and the polyester resin laminated TFS
The corrosion resistance is superior to that of However, the manufacturing process of this surface-treated steel sheet is complicated, and it is difficult to control tin plating conditions for controlling the exposed portion of the steel sheet to a specific range.
Similarly, the appearance of the can body is a little blackish, which has the disadvantage of reducing the commercial value.

[0005]

A method for producing a material for cans suitable for organic resin coating which requires such strict processing adhesion and processing corrosion resistance in a simple process and at high speed has not been obtained. . An object of the present invention is to provide a method capable of producing a surface-treated steel sheet having both excellent work adhesion and work corrosion resistance and suitable for organic resin coating in a simple process.

[0006]

According to the present invention, as a result of various studies, it has been found that a steel sheet plated with tin or a steel sheet plated with tin and then further plated with a small amount of nickel (hereinafter referred to collectively as tin plating) It has been found that a surface-treated steel sheet suitable for organic resin coating with excellent workability can be obtained simply by applying and drying an acidic aqueous solution containing a halogen group or a carboxyl group on a steel sheet).

Hereinafter, the contents of the present invention will be described in detail. First, tin plating on a steel sheet in the present invention may be performed under known tin plating conditions using a known tin plating bath used for producing tinplate, for example, a ferrostan bath or a halogen bath. The tin plating amount may be 1.0 g / m ² or more. In general, when the amount of tin plating is small, most of the plated tin becomes iron-tin alloy by heating when curing the painted paint or when laminating the thermoplastic resin film, and subjected to severe deep drawing processing At this time, the iron-tin alloy layer is broken, and as a result, the coated film or the laminated thermoplastic resin film is peeled off. However, when the tin-plated steel sheet is immersed in the acidic aqueous solution of the present invention, although the cause is not clearly understood, the growth of the iron-tin alloy due to this heating is suppressed, and the residual amount of metallic tin increases. This phenomenon is considered to be one of the factors that improve the processing adhesion of the organic resin coating layer in the present invention. In addition, the treatment with the acidic aqueous solution of the present invention has no effect unless tin or nickel is present. This is considered to be one of the reasons why the processing adhesion is improved. Although there is no need to limit the upper limit of the amount of tin plating, 7.4 is considered from the viewpoint of economy.
g / m ² . In addition, the treatment of the present invention may be performed after tin plating, or after tin plating, and after further applying nickel plating to the upper layer thereof, after the tin melting treatment performed in a usual tinning, the object of the present invention is particularly preferable. It does not interfere with the effect of doing so.

FIG. 1 shows the process of the present invention, that is, 1 g / 1
A tin-plated steel sheet immersed in a hydrochloric acid aqueous solution at room temperature for 1 second, squeezed and dried with a roll, heated at 220 ° C. for 30 minutes, and then cross-sectioned from the surface layer to the inner layer using a glow discharge spectrometer (hereinafter referred to as GDS). The result of having measured the intensity | strength of tin and iron in the direction is shown. Figure 2 shows a tin-coated steel sheet at 220 ° C.
This is a result of measuring the strength of tin and iron after heating for 30 minutes in the same manner as in FIG. In both cases, two peaks are observed in the intensity of tin, a first peak due to metallic tin and a second peak mainly composed of an iron-tin alloy, but iron is detected near the second peak of tin. However, it can be seen that the iron strength when the treatment of the present invention was performed (FIG. 1) was smaller than that when the treatment of the present invention was not performed (FIG. 2). It must be considered that the measurement sample is heated by the glow discharge and the iron-tin alloy grows to some extent. However, it is understood that when the treatment of the present invention is performed, the iron-tin alloy hardly grows by heating.

In the case of applying nickel plating after tin plating,
The nickel plating may be performed using a known nickel plating bath, that is, a Watt bath or a sulfamic acid bath, under known plating conditions. Nickel plated on tin can be easily alloyed with tin even when left at room temperature, or when curing the coated paint, or even when heating a thermoplastic resin film, so that the coating film or This has the effect of improving the processing adhesion of an organic resin coating layer such as a laminated thermoplastic resin film. When the nickel plating amount is 0.005 g / m ² or less, the effect is hardly obtained. In addition, the increase in the amount of nickel plating does not affect the processing adhesion of the organic resin coating layer regardless of the amount of tin plating. However, when the amount of tin plating is small, the formation of tin-nickel alloy causes And the corrosion resistance of the surface-treated steel sheet coated with the organic resin layer is lowered, which is not preferable. Metal tin has the effect of electrochemically protecting the exposed steel sheet when fine cracks are formed in the organic resin coating layer by processing, so in the present invention, from the viewpoint of corrosion resistance after processing, the painted paint It is indispensable that the metallic tin remains even after the curing or the heating at the time of laminating the thermoplastic resin film. Considering the suitable range of the amount of tin plating in the present invention, the amount of nickel plating is 0.1.
The range of 005 to 0.20 g / m ² is preferred. Nickel plating after tin plating has the effect of further improving the processing adhesion of the organic resin coating layer as described above, and despite the increase in the number of manufacturing processes, the organic resin coating with excellent processing adhesion and processing corrosion resistance It is possible to manufacture steel sheets for use continuously and in a stable state.

In the method of the present invention, a specific acidic aqueous solution is applied after tin plating, or after tin plating, and further by nickel plating, and in place of electrolytic chromic acid treatment or the like, which is performed as a usual post-treatment. It is characterized by drying. As a result of various investigations, it was found that an aqueous solution of a compound containing a halogen group or a carboxyl group was formed on the surface by applying a tin-plated surface or a tin-plated surface and then applying a small amount of nickel plating on the upper layer. It has been found that the processing adhesion of the organic resin coating layer is remarkably improved. Examples of the compound containing a halogen group used in the method of the present invention include hydrofluoric acid, hydrosilicofluoric acid, borofluoric acid, hydrochloric acid, hypochlorous acid, ammonium salts, alkali metal salts, and alkaline earth metal salts thereof. , Tin, nickel, zinc and the like. Examples of the compound containing a carboxyl group include aliphatic, aromatic carboxylic acids such as formic acid, acetic acid, propionic acid, oxalic acid, citric acid, tartaric acid, malic acid, benzoic acid, and salicylic acid, and ammonium salts, alkali metal salts, and alkaline earth salts thereof. Metal salts such as metal salts, tin, nickel, and zinc. These compounds containing a halogen group or a carboxyl group can be used alone or as a mixture of two or more. However, when the aqueous solution shows alkalinity,
It is indispensable in the present invention to make it acidic by adding the above-mentioned acids. If the aqueous solution used is alkaline, the alkaline substance remaining on the surface of the tin-plated steel sheet is coated with an organic resin when it is aged in a state of being immersed in hot water or the like, particularly when it is immersed in hot water or the like. The adhesion of the layer is significantly deteriorated, which is not preferable.

In the method of the present invention, the concentration of the compound containing a halogen group or a carboxyl group in the acidic aqueous solution used is preferably in the range of 0.01 to 20 g / l, more preferably 0.1 to 10 g / l. The concentration is 0.0
When it is 1 g / l or less, even if applied to a tin-plated steel sheet, there is almost no effect on the working adhesion of the coating film or the thermoplastic resin film. When the concentration is 20 g / l or more, the amount of the compound remaining on the plated tin surface also increases,
There is a risk that the processing adhesion of the coating film or the thermoplastic resin film may be deteriorated. In particular, when the pH of the acidic aqueous solution is extremely low, there is a high risk that the plated tin will be dissolved, which is not preferable. That is, in the method of the present invention, the above compound is maintained at a concentration within an appropriate range,
It is more preferable to use an acidic aqueous solution controlled to about 1 to 5. There are various methods for applying the acidic aqueous solution to the tin-plated steel sheet, such as a method of spraying the aqueous solution on the tin-plated steel sheet, a method of dipping the tin-plated steel sheet in the aqueous solution and squeezing with a roll, and a method of applying with a roll like a paint. However, there is no particular limitation. Soak,
In the method of squeezing with a roll, it is not necessary to immerse in the acidic solution of the present invention for a long time. In particular, when the pH of the acidic aqueous solution used is extremely low, the plated tin dissolves as described above, which is not preferable. Also, the temperature of the acidic aqueous solution is sufficient at room temperature, and there is no particular need to heat it.

The paint applied to the tin-plated steel sheet obtained by the method of the present invention includes various known paints widely used as paints for cans, and the tin-plated steel sheet obtained by the method of the present invention. Has excellent processing adhesion to these paints. Particularly effective for epoxy-phenol-based, epoxy-urea-based and vinyl chloride organosol-based paints. In addition, the thermoplastic resin film laminated on the tin-plated steel sheet obtained by the method of the present invention includes a polyolefin resin film, a polyester resin film, a polyamide resin film, and the like, and is also superior to these various resin films. It has good processing adhesion. In particular, for applications requiring strict work adhesion and work corrosion resistance, which are the objects of the present invention, the tin-plated steel sheet obtained by the method of the present invention is coated with a thermosetting paint, and the processing of the organic resin layer itself is performed. It is more preferable to coat with a thermoplastic resin film having excellent properties. For example, use of a copolymerized polyester resin film having excellent processability, which is disclosed in JP-A-1-249331, is suitable for the use of the present invention.

The method of applying the paint to the tin-plated steel sheet obtained by the method of the present invention and the method of curing are not particularly limited, and known methods are sufficient. Also, a known method is sufficient for laminating a thermoplastic resin film.
For example, temporarily bonded to a steel sheet heated to a temperature equal to or lower than the melting temperature of the thermoplastic resin film, and then heated to a temperature equal to or higher than the melting temperature of the resin, a method of real bonding, the thermoplastic resin film was heated to the melting temperature or more. A method of laminating on a steel sheet, melting part or all of the film in contact with the steel sheet surface, a method of laminating a thermoplastic resin film coated with a known adhesive in advance on a steel sheet heated to about its melting temperature, After applying a known adhesive on the surface, heating,
Although there are various methods such as a method of laminating a thermoplastic resin film, any of the methods can be applied to the tin-plated steel sheet obtained by the method of the present invention.

[0013]

EXAMPLES Examples of the present invention and comparative examples will be described below.

Example 1 A cold-rolled steel sheet having a thickness of 0.18 mm and a temper degree of DR-10 was prepared.
Both sides are degreased and pickled by a known method, washed with water, and (1)
After tin plating under the conditions shown in
1 Immerse in hydrochloric acid aqueous solution for 1 second, squeeze with roll, and dry
Dried. On both sides of the obtained tin-plated steel sheet, the strips shown in (2)
In this case, a polyester resin film was laminated. After lamination, 2
Heated at 10 ° C. for 1 minute. (1) Tin plating conditions Bath composition Tin sulfate: 80 g / l Phenolsulfonic acid (acidity converted to sulfuric acid): 15
g / l ethoxylated α-naphthol: 10 g / l bath temperature: 45 ° C. cathode current density: 20 A / dm²  Tin plating amount: 1.8 g / m²  (2) Lamination conditions of polyester resin film Characteristics of the film Composition: terephthalic acid 88 mol%, isophthalic acid 12 mol
%, Ethylene glycol 100 mol%
Biaxially stretched copolymerized polyester resin film Thickness: 25 μm Melting point: 230 ° C. Application of adhesive to film Adhesive composition: 80 parts epoxy resin 20 parts paracresol-based resole Coating amount: 0.25 g / m²(Dry weight) Drying temperature: 100 ° C. Film lamination conditions Temperature of tin-plated steel sheet immediately before film lamination: 245 ° C Lamination speed: 30 m / min

Example 2 Tin-plated 5.6 g / m ² of tin was applied to both surfaces of the cold-rolled steel sheet used in Example 1 under the tin plating conditions shown in (1) of Example 1, and after washing with water, Ammonium fluoride 15 at 35 ° C
g / l, 3 g / l aqueous solution of hydrofluoric acid for 3 seconds,
It was squeezed with a roll and dried as it was. Then, a film having the same composition as used in Example 1 was laminated on both surfaces of the obtained tin-plated steel sheet without applying an adhesive under the conditions shown in (1) of Example 1.

Example 3 On both sides of the cold-rolled steel sheet used in Example 1,
2.8 g / m of tin plating under the indicated tin plating conditions²No tin
After washing with water, nickel plating is applied under the conditions shown in (1).
Was given. After washing, add 0.5g / l at 40 ℃
Spray the phosphoric acid solution for 2 seconds, squeeze it with a roll,
It was dried as it was. Then, both sides of the obtained tin plated steel sheet
And 120 mg / dm2 of vinyl chloride organosol paint
²It was applied and cured at 205 ° C. for 10 minutes. (1) Nickel plating conditions Bath composition Nickel sulfate: 250 g / l Nickel chloride: 30 g / l Boric acid: 30 g / l pH: 3-4 Bath temperature: 50 ° C. Cathode current density: 5 A / dm²  Nickel plating amount: 0.02 g / m²

Example 4 The cold-rolled steel sheet used in Example 1 was subjected to tin plating at a tin plating amount of 3.6 g / m ^{2 under} the tin plating conditions shown in (1) of Example 1 and washed with water. 5g / l hydrochloric acid at 25 ° C, 5g / 1
It was immersed in an aqueous solution of tin chloride for 1 second, squeezed with a roll, and dried as it was. A polyamide resin film was laminated on both sides of the obtained tin-plated steel sheet under the conditions shown in (1).
Heated at 10 ° C. for 1 minute. (1) Lamination conditions of polyamide resin film Film properties Composition: Nylon 6 Thickness: 25 μm Melting point: 225 ° C. Application of adhesive to film Adhesive composition: The same as the adhesive composition used in Example 1. Coating amount: 0.25 g / m ² (dry weight) Drying temperature: 100 ° C. Film lamination conditions Temperature of tinned steel sheet immediately before film lamination; 258 ° C Laminating speed: 10 m / min

Comparative Example 1 The cold-rolled steel sheet used in Example 1 was tin-plated with a tin plating amount of 1.8 g / m ^{2 under} the tin plating conditions shown in (1) of Example 1 and then washed with water. And 30 g of chromic anhydride at 50 ° C
/ L, 0.3 g / l sulfuric acid in aqueous solution
Electrolyzed under the condition of 0 A / dm ² , the upper layer has a chromium content of 14 mg / m ^{2 as} a chromium hydrate oxide on the plated tin,
A lower layer was formed of a two-layer film composed of 40 mg / m ² of chromium metal, washed with water and dried. Further, a polyester resin film was laminated under the conditions shown in (2) of Example 1.

Comparative Example 2 Under the conditions shown in (1) of Example 1, the tin plating amount was 2.8 g /
After applying a tin plating m ^2, washed with water, subjected to an electrolytic chromic acid treatment under the conditions shown in Comparative Example 1 to form a similar double-layer film it was washed with water and dried. Further, the vinyl chloride organosol paint used in Example 3 was applied at 120 mg / m ² ,
The mixture was cured at 05 ° C. for 10 minutes.

Comparative Example 3 The cold-rolled steel sheet used in Example 1 was subjected to tin plating at a tin plating amount of 2.8 g / m ^{2 under} the tin plating conditions shown in (1) of Example 1 and washed with water. Electrolysis was carried out in a 30 g / l sodium bichromate aqueous solution at 45 ° C. under the condition of a cathode current density of 20 A / dm ² , and the amount of chromium was 5 mg / m ² on the plated tin.
Was formed, washed with water and dried. The polyester resin film of the same composition used in Example 1 was coated on both sides of the obtained tin-plated steel sheet without applying an adhesive,
Lamination was performed under the conditions shown in (1) of Example 1.

Comparative Example 4 Both sides of the cold-rolled steel sheet used in Example 1 were subjected to the conditions shown in (1).
Electrolytic chromic acid treatment, the lower layer is metallic chromium and the upper layer is
Two-layer coating made of ROHM hydrated oxide, so-called TFS coating
Is formed, washed with hot water, and dried under the conditions of (1) in Example 2.
A polyester resin film was laminated. (1) Electrochromic acid treatment conditions Bath composition Chromic anhydride: 30 g / l Sodium fluoride: 1.2 g / l Bath temperature: 45 ° C. Cathode current density: 40 A / dm²  Metal chromium amount: 104mg / m²  Chromium hydrated oxide amount: 16 mg / m²(With chrome
hand)

The organic resin-coated steel sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were processed into thinned deep drawn cans under the following conditions. The peeling state of the organic resin coating layer in each processing step was visually observed. Furthermore, 1.5% citric acid aqueous solution was filled in 50 obtained thinned deep-drawing cans, and 37.5
The solution was stored in a constant temperature room at 3 ° C. for 3 months, the amount of eluted iron was measured by the atomic absorption method, and the rate of occurrence of leaking cans due to pitting was determined. The amount of eluted iron was shown as an average value of 50 cans. In addition, in the process of processing the organic resin-coated steel sheet obtained in Comparative Example 1 and Comparative Example 3 into a thinned deep-drawn can, the laminated polyester resin film was peeled off as shown in Table 1, so the citric acid solution was used. Not filled. [Processing conditions for thinning deep drawn can] Drawing process Blank diameter: 187 mm Drawing ratio: 1.50 Redrawing Step Primary Redrawing Ratio: 1.29 Secondary Redrawing Ratio: 1.24 Tertiary Redrawing Ratio: 1.20 Curvature Radius of Corner of Die in Redrawing Step:
0.4 mm Wrinkle holding load in redrawing process: 6000 kg Average thinning rate of can body: against the steel sheet thickness before forming
20%

[0023]

[Table 1]

[0024]

The surface-treated steel sheet for organic resin coating obtained by the method of the present invention has excellent processing adhesion of the organic resin layer coated thereon, excellent processing corrosion resistance, strict processing adhesion and processing. It can be widely applied not only for DRD cans requiring corrosion resistance and for thinned deep drawn cans, but also for container materials such as can lids, crowns and screw caps.

[Brief description of the drawings]

FIG. 1 shows a temperature of 220 ° C. of a tin-plated steel sheet treated according to the present invention.
FIG. 4 is a diagram showing the results of measuring the strength of tin and iron in the direction from the surface to the inner layer by GDS after heating for 30 minutes at.

FIG. 2 shows a case where a tin-plated steel sheet not subjected to the treatment of the present invention is subjected to 220
It is a figure which shows the result of having measured the intensity | strength of tin and iron in the inner layer direction from the surface layer by GDS after heating at 30 degreeC for 30 minutes.

[Explanation of symbols]

 1 Change in strength of tin 2 Change in strength of iron

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-83775 (JP, A) JP-A-57-16175 (JP, A) JP-A-61-210184 (JP, A) JP-A 54-183 68734 (JP, A) JP-A-49-123941 (JP, A) JP-A-48-8317 (JP, A)

Claims (4)

(57) [Claims] 1. An organic resin excellent in processing adhesion, characterized in that both surfaces of a steel sheet are tin-plated, washed with water, treated with one or more of the following aqueous solutions (a) to (f), and dried. A method for producing a surface-treated steel sheet for coating. (A) one or more of hydrofluoric acid, hydrosilicofluoric acid, borofluoric acid, hydrochloric acid or hypochlorous acid; (b) one of the ammonium salts, alkali metal salts or alkaline earth metal salts of the above (a) (C) one or more of the tin salt, nickel salt or zinc salt of (a); (d) one or more of formic acid, acetic acid, propionic acid, oxalic acid, citric acid, tartaric acid, malic acid, benzoic acid or salicylic acid (E) at least one of the ammonium salt, alkali metal salt or alkaline earth metal salt of (d); and (f) at least one of tin salt, nickel salt or zinc salt of (d). 2. A process adhesion characterized in that both sides of a steel sheet are tin-plated, then nickel-plated, washed with water, treated with one or more of the following aqueous solutions (a) to (f), and dried. Method of producing surface treated steel sheet for organic resin coating excellent in quality. (A) one or more of hydrofluoric acid, hydrosilicofluoric acid, borofluoric acid, hydrochloric acid or hypochlorous acid; (b) one of the ammonium salts, alkali metal salts or alkaline earth metal salts of the above (a) (C) one or more of the tin salt, nickel salt or zinc salt of (a); (d) one or more of formic acid, acetic acid, propionic acid, oxalic acid, citric acid, tartaric acid, malic acid, benzoic acid or salicylic acid (E) at least one of the ammonium salt, alkali metal salt or alkaline earth metal salt of (d); and (f) at least one of tin salt, nickel salt or zinc salt of (d). 3. The concentration of the aqueous solution is 0.01 to 20 g / l.
The method for producing a surface-treated steel sheet according to claim 1 or 2, wherein 4. The plating method according to claim 2, wherein the amount of tin plating is 1.0 to 7.4 g / m ² , the amount of nickel plating is more than 0.005 g / m ² , and A method for producing a surface-treated steel sheet in which the amount of metallic tin is less than that required for alloying all when forming a tin-nickel alloy.