JPH03221219A - Manufacture of drawn and squeezed can - Google Patents

Abstract

PURPOSE:To obtain a steel can excellent in color tone on its outer surface by forming a tin electroplating layer of a specific amt. and a zmc electroplating layer under a specific amt. from the front surface side of a steel sheet on this steel sheet surface, squeezing so as that this plating surface is made to the front surface, and then executing substituting plating of a tin. CONSTITUTION:In order to allow the tin electroless plating on the drawn and squeezed can (DI can), the DI work is executed by utilizing the surface treated steel sheet plated with a zinc-plating on the upper layer, after then, it is immersed in the tin plating bath to substitute zinc and precipitate tin. The surface treated steel sheet formed with the tin electroplating layer of 2.8-5.6g/m<2> and the zinc electroplating layer of <5.0g/m<2> from steel sheet surface side of one side, at least, of the steel sheet surfaces, is squeezed so as to be the zinc/tin plating surface an outer surface of can and the DI-can is obtained. After washing this DI-can, it is immersed in the tin plating bath, and the substituting plating of tin is executed. Therefore, the steel DI-can excellent in appearance of color tone equal to the aluminium DI-can is easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a drawn and ironed can using a steel plate.

(Prior Art) Generally, squeezed cans (hereinafter abbreviated as DI cans) are used as containers for drinks, carbonated drinks, and the like.

Conventionally, in the production of DI cans using steel plates, 2.8~
Steel sheets electroplated with 5.6 g/rn' tin (hereinafter referred to as electro-tin plated steel sheets) and JP-A No. 49119836
0.5 to 1.0 g/, on the surface as shown in the publication.
Electroplated nickel of 2.8 to 5.6 l on top.
A steel plate electroplated with tin of g/rn' (hereinafter abbreviated as electro-tin/nickel plated steel plate) is used. That is, in order to ensure workability in the drawing and ironing process, electrolytic tin-plated steel sheets or electrolytic tin/nickel-plated steel sheets that utilize the lubrication of the tin plating layer are used.

(Invention or problem to be solved) The DI can (hereinafter abbreviated as steel DI can) using this electro-tin plated steel plate or electro-tin/nickel plated steel plate is:
Compared to DI cans using aluminum plates (hereinafter abbreviated as aluminum DI cans), steel DI cans have a poor external color tone, that is, steel DI cans have a blackish color tone and poor printing finish, especially white printing finish.

The present invention improves the surface treatment process for steel sheets as well as the surface treatment method for DI cans carried out after DI processing.4 Steel DI cans with excellent external color tone4 For example, steel DI cans with an external color tone comparable to that of aluminum DI cans. The present invention provides a method for manufacturing steel DI cans that can be easily obtained.

(Means for solving the problem) The reason why the external color tone of steel DI cans is inferior to that of aluminum DI cans is because the pot is not sufficiently covered after DI processing, and the iron surface of the base material is exposed. be.

The present invention attempts to improve the external color tone of the steel DI can by performing electroless plating of tin after processing the exposed iron. However, electroless plating of tin on exposed iron surfaces is usually quite difficult, takes a long time, and requires strict control of bath conditions, making it impractical for application in the quick surface treatment process of DI cans. .

In the present invention, in order to easily perform electroless plating of tin in the above-mentioned surface treatment process of DI cans, improvements are made to the surface treatment of the steel plate side. In other words, D
I processing is performed, and then in the DI can surface treatment process, the zinc on the steel plate is dissolved by dipping into a tin plating bath, and tin is precipitated by replacing it with zinc, improving the tin coverage on the outer surface of the DI can. This improves the external color tone of steel DI cans.

That is, the present invention provides a surface-treated steel sheet in which an electrolytic tin plating layer of 2.8 to 5.6 g/rn'' and an electrolytic galvanizing layer of 5.0 g/m or less are formed on at least one side of the steel sheet surface from the steel sheet surface side. A drawn and ironed can is obtained by drawing and ironing so that the zinc/tin plating surface becomes the outer surface of the can, and then, after washing this drawn and ironed can, it is immersed in a tin plating bath to perform tin displacement plating. Also, on at least one side of the steel sheet surface, an electrolytic nickel plating layer of 0.5 to 1.0 g/m from the steel sheet surface side, an electrolytic tin plating layer of 2.8 to 5.6 g/m, and a 5.0 g7. A surface-treated steel sheet on which an electrogalvanized layer has been formed is drawn and ironed to form a zinc/tin/nickel plated surface or the outer surface of the can to obtain a drawn and ironed can, and then after cleaning this drawn and ironed can. This is a method for manufacturing a drawn and ironed can, which is characterized by immersing it in a tin plating bath to perform tin displacement plating.

(Function) The content of the present invention will be explained in more detail below along with the function.

First, a method for surface treatment of a steel plate will be explained.

As described above, DI cans using steel plates are electrolytically tin-plated or electrolytically nickel-plated to improve DI workability, and then electrolytically tin-plated on top of the electrolytic tin plating or nickel plating. A feature of the present invention is that a zinc plating layer is provided on top of the tin plating layer within a range that does not impair DI processability.

The upper limit of the thickness of this zinc plating layer (zinc plating amount) may be set to below an amount that does not impair DI workability as described above, in other words, below an amount that does not impair the warming effect of the tin plating layer. According to the research results, under normal DI processing conditions, the amount of zinc plating on the upper layer is 2.8 to 5°6 g/d, and when there is no nickel plating layer below the tin plating, the amount of zinc plating on the lower layer is 5. A value of .0g/rrr or less is appropriate. In other words, if the tin plating amount is 2.8 to 5.6 g/n (and the upper layer zinc plating amount is 5.0 g/n or less, the DI processability is within the practical range and is good, and an I can is manufactured. In addition, the amount of zinc plating on the upper layer may be such that the amount of tin plating on the lower layer is 2.8 to 5.6 g/m and the amount of nickel plating on the lower layer of tin plating is 0.5 to 1.0 g/m. Similarly 5.
A value of 0 g/m or less is appropriate. In other words, the amount of nickel plating is 0.
．． 5-1. Og/m + If the amount of tin plating on the upper layer of nickel plating is 2.8 to 5.6 g/m, and the amount of zinc plating on the upper layer of tin plating is 5.0 g/rrr or less, D.
The I-processability is within a practical range, and it is possible to produce I-cans with good quality.

Next, the lower limit of the amount of zinc plating will be explained. The purpose of the present invention is to improve the external color tone of DI cans manufactured from steel plates, and the method involves electroless plating of tin in the surface treatment process of DI cans after DI processing. As described above, the coverage is improved and the exposed portion of the iron base is reduced.

In addition, in order to facilitate this electroless plating of tin, a galvanized layer is provided on the outermost layer of the steel sheet, and by immersing it in a tin plating bath, electroless plating of tin (tin is precipitated by replacing zinc).
This is what we do. In this way, the amount of zinc plating corresponds to the amount of displacement plating of tin, and as the amount of zinc plating increases within the range below the above upper limit, the improvement in the above tin coverage (reduction formula of the exposed part of the iron substrate) increases. Therefore, there is a large margin for improving the color tone of the outer surface of the can. In other words, the outer surface color level of the can differs depending on the amount of zinc plating, the lower limit of the amount of zinc plating differs depending on the required level of outer surface color, and the lower limit of the amount of zinc plating is determined according to the required level of outer surface color. Therefore, in the present invention, the amount of zinc plating is The lower limit of is not particularly limited.

As mentioned above, increasing the amount of zinc plating within the range between the upper limit determined by DI processability and the lower limit determined by the required external color tone level of the can is not preferable from the viewpoint of manufacturing costs.

Therefore, in accordance with the required level of external color tone of the can, the minimum amount of zinc plating required should be determined and adopted from the amount of displacement tin plating required to satisfy the required level of tin coverage determined by the required level of external color tone. preferable.

According to the results of research conducted by the present inventors, the lower limit of the amount of zinc plating to improve the external color tone to the level of aluminum DI can is to use an electrolytic tin-plated steel sheet with a general tin plating amount of 2.8 g/rn'. In the case of a steel can made of electro-tinned steel can with a tin plating amount of 5.6 g/m, the amount is 1.0 g/m', and in addition, the amount of nickel plating is 0.5 g/m'. ~1.0g/m + tin plating amount 2゜0.5g/d for steel cans using electrolytic tin/nickel plated steel sheets with 8 to 5.6g/m, and steel with an exterior color similar to that of aluminum DI cans. When obtaining a DI can, it is preferable to adopt the lower limit of the zinc plating amount mentioned above from the viewpoint of manufacturing cost.

Next, surface treatment after DI processing will be explained.

Another feature of the present invention is that a steel plate with zinc plating applied on the tin plating layer is subjected to DI processing to form a steel DI can, and then immersed in a pot plating bath to electrolessly plate tin. . Usually, DI cans processed using electro-tin plated steel plate, electro-tin/nickel plated steel plate or aluminum plate are D
Cleaned with cleaning fluid to remove debris (lubricating oil, etc.) from I processing. Next, it is subjected to chemical conversion treatment in a chemical conversion treatment bath (phosphate tower, zirconate bath, etc.) for the purpose of improving paintability and rust resistance. In the present invention, either tin plating is performed instead of this chemical conversion treatment, or a new treatment step is provided after the cleaning step before this chemical conversion treatment, tin plating is performed, and then chemical conversion treatment is performed. Providing a new treatment process is unfavorable in terms of manufacturing costs, and it is recommended to use a tin plating bath for electroless plating of tin instead of the chemical conversion treatment bath currently used in the normal DI can treatment process. It is preferable to adopt it.

That is, according to the preferred method of the present invention, the can after DI molding is cleaned according to a normal process. Afterwards, it is subjected to displacement tin plating in a pot plating bath, and then painted and printed.

Next, the tin plating bath referred to in the present invention will be explained.

In the present invention, since the outermost layer of the steel sheet is galvanized to facilitate electroless plating of tin, a special electroless plating bath is used as the tin plating bath (normal electroless plating baths do not contain reducing agents). There is no need to use a reducing agent to reduce and precipitate tin, and the zinc on the surface dissolves, at which time tin is reduced and precipitated as metal. That is, when zinc is dissolved, tin is displacement plated. Therefore, as a tin plating bath,
A tin sulfate bath, a ferrostane bath (phenol sulfonic acid bath), a phosphoric acid bath, etc., which are generally used in electro-tin plating, can be used. Other alkaline tin plating baths are also available.

(Example) Hereinafter, description will be made according to examples.

Example - ■ Ordinary low carbon cold rolled steel plate (thickness 0) used for DI can manufacturing
．． 28 mrn) was degreased, pickled, and Sn-plated on both sides using an electric tin plate under the following conditions, then 2N plating was applied on the Sn plating on one side, and then chromate treatment was applied to both sides to form a DI can. manufactured steel plates.

As a comparative material, ordinary electric tin plate for DI cans, which was only Sn-plated but not Zn-plated, was used.

[Degreasing, pickling, electroplating, chromate treatment conditions (11
Degreasing NaOH 30g/l Bath temperature 60'CIO
A/drn”1 second Cathode electrolytic degreasing (2) Acid washing H2SO150g/1 Bath temperature 30
°CI OA/d rn'1 second Cathode electrolytic pickling f3) Sn plating 5nSO, 60g# PSA (
phenolsulfonic acid) 50g# Bath temperature 50°C 2OA/drn' Cathode electrolytic treatment (4) 2n plating Zn5Ot 150g/l
H2SO4log/1 Bath temperature 50°C 20A/d resistance Cathode electrolysis treatment (5) Chromate treatment Na, Cr, 0730g/l
The steel plate was immersed for 2 seconds in a bath with a bath temperature of 40° CPH 4.5. Next, this steel plate was subjected to DI processing under normal conditions so that it became the 2N/Sn plated surface or the outer surface of the can (thickness after DI processing was 0.100 mm). ). Thereafter, this DI can was degreased with an alkaline degreasing solution, and then Sn substitution plating was performed under the following conditions.

C3n displacement plating conditions] (11 Bath composition 5nS0.60g/I PSA (phenolsulfonic acid) 50g/1 (2) Bath temperature 40-60°C (3) Immersion time (plating time) 20 seconds Manufactured in this way The whiteness of the outer surface of the can body of the DI can was investigated by printing with white ink (coating amount: 50 cm/drn').

Table 1 shows the tin plating amount, zinc plating amount, displacement tin plating amount, and after DI processing and displacement tin plating of the sample materials.

The whiteness (L value) of the outer surface of the can body after printing is shown.

Table 1 also shows Comparative Example 3, in which the outer surface of the can body of an aluminum DI can using an aluminum plate was printed with white ink (coating film amount: 50 cm/
The whiteness (L value) of the outer surface of the can body after dr+() is also shown.

The whiteness (L value) is measured using an automatic colorimeter (Ska tester).
m AIJ-CH-1) using Te JIs Z8701
i: Measured based on

Example - ■ Ordinary low carbon cold rolled steel plate (thickness 0) used for DI can manufacturing
．． Degrease, pickle, and Ni plating are performed on both sides of the 2h + m) under the following conditions on an electric tin plating line, then Sn plating is applied on the Ni plating, and then Zn plating is applied on the Sn plating on one side, and then A steel plate for DI cans was manufactured by performing chromate treatment on both sides.

As a comparison material, an ordinary electric Sn/Ni plating for DI cans was used, which was coated with Ni plating and Sn plating without Zn plating.

[Degreasing, pickling, electroplating, chromate treatment conditions] (1
) Degreasing Na0) 130g/l Bath temperature 60'CI
OA/di 1 second Cathode electrolytic degreasing (2) Acid washing H2SO450g, I bath temperature 300CI
OA/drr? 1 second Cathodic electrolytic pickling (3) Ni plating Ni50.200 g/l H2S
O,lOg#? Na2B40+ 20g/l bath temperature 50
0C10, A/drn' Cathode electrolytic treatment (4) Sn plating 5nS0.60g# PSA (
phenolsulfonic acid) 50g/f Bath temperature 50°C
2OA/dm Cathode electrolytic treatment (5) Zn plating ZnS0. 150g/IH
2SO, lOg/R bath temperature 50°C2OA/dtn'
Cathode electrolytic treatment (6) Chromate treatment Na2Cr20t 30g/
12 Immersed in a bath with a bath temperature of 40°C and pH 4.5 for 2 seconds. Next, this steel plate was subjected to DI processing under normal conditions so that it became the Zn/Sn/Ni plated surface or the outer surface of the can (the thickness after DI processing was 0.100mm). Thereafter, this DI can was degreased with an alkaline degreasing solution, and then Sn substitution plating was performed under the following conditions.

(Sn displacement plating conditions) (1) Bath composition 5nS0.60g/j' PSA (phenolsulfonic acid) 50g/1 (2) Bath temperature 40 to 60°C (3) 4-day plating time (plating time) 20 seconds like this The whiteness of the outer surface of the can body was investigated by printing with white ink (coating amount: 50 mg/drn') on the outer surface of the can body of the DI can produced in the following manner.

Table 1 also lists the details of the sample materials and the evaluation results.

A comparison of Examples 1 and 2.3 in Table 1 and Comparative Example 1 shows that tin displacement plating was performed for the first time by applying zinc plating to the surface of an electro-tinned steel sheet with a tin plating amount of 2.8 g/m. The external color tone of the DI can was improved, and furthermore, referring to Comparative Example 3, 2.0 g/rn' was applied to the surface of the electro-tinned steel sheet.
It can be seen that by applying the above zinc plating, the external color tone can be improved to the level of an aluminum DI can.

Comparing Examples 4 and 5.6 with Comparative Example 2, it is found that by applying zinc plating to the surface of an electro-tin plated steel sheet with a tin plating amount of 5.6 g/rn', tin displacement plating is performed for the first time and DI The external color tone of the can was improved, and further referring to Comparative Example 3, by applying zinc plating of 1.0 g/m or more to the surface of the electro-tin plated steel sheet, the external color tone was improved.
I can see how it will improve my health.

Furthermore, when comparing Examples 7 and 8.9 and Comparative Examples 4 and 5.6, it is found that electrolytic tin with a nickel plating amount of 0.5 to 1.0 g/rn' and a tin plating amount of 2.8 to 5.6 g/m /By applying zinc plating to the surface of nickel-plated steel sheet, the external color tone can be improved to the extent of aluminum DI can health by applying zinc plating of 0.5 g/m or more to the surface of nickel-plated steel sheet. I understand that.

(Effect of the invention) As detailed above, according to the method of the present invention, for example, aluminum D
Steel 01 cans with an excellent external color tone comparable to I cans can be easily obtained.

Claims (2)

[Claims] (1) 2. From the steel plate surface side on at least one side of the steel plate surface.
Electrotin plating layer of 8-5.6g/m^2 and 5.0g
A surface-treated steel sheet on which an electrogalvanized layer of /m^2 or less has been formed is drawn and ironed so that the zinc/tin plating surface becomes the outer surface of the can to obtain a drawn and ironed can, and then after cleaning this drawn and ironed can. A method for manufacturing a drawn and ironed can, characterized by immersing it in a tin plating bath to perform tin displacement plating. (2) At least one side of the steel plate surface has a 0.
Electrolytic nickel plating layer of 5-1.0g/m^2, 2.8
~5.6g/m^2 electro-tin plating layer and 5.0g/m^2
A surface-treated steel sheet on which an electrogalvanized layer of m^2 or less was formed was drawn and ironed so that the zinc/tin/nickel plated surface became the outer surface of the can to obtain a drawn and ironed can, and then this drawn and ironed can was washed. A method for manufacturing a drawn and ironed can, which is characterized by subsequently immersing the can in a tin plating bath to perform tin displacement plating.