JPS6350493A - Production of aluminum foil laminated steel sheet having superior workability and corrosion resistance - Google Patents

Abstract

PURPOSE:To obtain an Al foil laminated steel sheet for a food or drink can having superior suitability to drawing and ironing and superior resistance to corrosion by food or a drink to be filled by plating one side of a steel sheet with Ni or Cr, tinning the other side and adhering Al foil to both sides. CONSTITUTION:A cold rolled soft low-C steel sheet is used as a material for a vessel such as a food or drink can. One side of the steel sheet corresponding to the inside of the can is plated with Ni by 100-2,000mg/m<2> and/or Cr by 50-200mg/m<2>. The other side corresponding to the outside of the can is tinned by >=1,000mg/m<2> and then Al foil is firmly adhered to one side or both sides of the steel sheet with a resin adhesive such as olefin-polyester resin or acrylic resin. A steel sheet for a can having superior resistance to corrosion by food or a drink to be contained and superior suitability to pressing, drawing and ironing is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing aluminum foil laminated steel sheets with excellent workability and corrosion resistance, which are used as materials for food cans, beverage containers, and other various containers.

Conventional technology Sn-plated steel sheets used in food cans, etc., which are formed into various shapes by pressing or drawing and ironing, are spray-painted twice after forming to ensure corrosion resistance against the filling contents. This prevents corrosion resistance from deteriorating due to pinholes that occur frequently during coating.

However, this two-coat container manufacturing method is
There are problems such as paint loss during spraying and thermal energy loss during baking after painting, which is not desirable from the standpoint of resource and energy conservation.

As a steel plate that solved these problems, JP-A-56-1
``A resin-coated metal plate in which a metal plate is coated with a polyester film via an adhesive'' as described in Japanese Patent Publication No. 0451, and ``Sn plating on at least one side of the metal plate as described in Japanese Patent Publication No. 131-3878. There is a resin-coated metal plate with a resin film bonded to it.

These steel plates have excellent impact resistance, retort resistance, corrosion resistance, and even workability.

Problems to be Solved by the Invention However, when performing severe forming processes such as drawing and ironing into DI cans, a steel plate with even better workability is required. Furthermore, when a resin-coated metal plate with Sn plating on the base is processed, there is a problem in that the adhesive strength between the laminated layers is insufficient and the plate cannot withstand drawing and ironing.

In particular, a resin-coated metal plate with Sn plating applied as a base on one side of the metal plate has the problem that the opposite non-plated side is corroded by the Sn plating bath during Sn plating, significantly impairing the laminated adhesive strength. was there.

The present invention thus provides a method for manufacturing an aluminum foil laminated steel sheet that eliminates the drawbacks of conventional resin-coated metal sheets and has excellent workability and corrosion resistance.

Means for Solving the Problems The present invention provides a coating with a coating weight of 100% on one side of the steel plate that forms the inner surface of the container.
~2000 g/intestine 2 Ni plating or 50-200
After applying one or two layers of Cr plating of 11 g/, 2, apply Sn plating of 5j (1000 + gg/m2 or more) to one side of the steel plate that becomes the outer surface of the container on the opposite side, and then apply Sn plating of 1000 + gg/m2 or more, and This is a method for manufacturing an aluminum foil laminated steel plate, characterized in that aluminum foil is laminated on one or both sides with an adhesive.

action The method of the present invention will be explained in detail below.

One side of a steel plate (ordinary carbon steel plate, stainless steel plate, etc.) that has been surface-cleaned through the normal surface treatment original plate manufacturing process,
In other words, there is a Xi plating layer or a C plating layer on the inner surface of the container.
The r plating layer or these two plating layers are not corroded by the Sn plating bath, and the adhesion between the laminated layers is increased by plating the steel plate prior to the Sn plating.

Such an effect is obtained when the Xi plating layer is 100 rag1 layer2
If the Cr plating layer is less than 50 mg/+*2, the effect cannot be obtained, and if the plating layer is excessively thick, the degree of effect that can be obtained,
Due to various properties such as processability and economic efficiency during molding, the Xi plating layer should be 2000 mg/m2 or less, and the Cr plating layer should be 200 I
It is preferable to set it as 1g/I12 or less.

In addition, when performing two-layer plating of these plating metals, it is sufficient to plate each with a specified amount of adhesion, and from the viewpoint of workability, the amount of two-layer plating (total) is 2200 + wg.
/m2 or less is preferable.

In addition, these plating baths are not particularly limited, but Ni
Commonly used baths such as a Watt bath or a sulfamic acid bath are used for plating, and a Sargent bath or a low concentration electrolytic chromic acid treatment bath (for tin-free steel production) are used for the Cr plating bath.

Applying a Sn plating layer to the opposite side of the one side plated in this way, that is, the surface that will become the outer surface of the container.
Sn-plated metal is used as a metal to improve the corrosion resistance of container materials, and in the present invention, it is used to exhibit a lubricating effect during drawing and ironing to prevent cracks that are likely to occur in the coating layer.

The adhesion amount of Sn plating is more than IQOOmg/s2,
The cooling effect required during processing can be obtained. The upper limit of the Sn plating amount is not particularly limited, but it is preferably 8000 mg/m2 or less from the viewpoint of removability during processing and economical efficiency. Commonly used items such as baths can be used.

The Ni or Or plating side of the plated steel plate, which has been plated with different metals on both surfaces of the steel plate as described above, or the Sn
Apply resin as an adhesive to the plated side or both sides to laminate the aluminum foil.

This resin is preferably one in the form of a film that melts under heat and adheres well to the plating layer, and commonly used resins such as olefin, polyester, acrylic, epoxy, phenol, and vinyl chloride may be used alone or in combination. and use it.

In this way, the aluminum foil is temporarily attached onto the semi-molten resin film, and then heated to a high temperature to strongly adhere the aluminum foil to the metal plating layer through the resin film. Aluminum foil is used because it has properties required for container materials such as corrosion resistance and aesthetics, and there are no particular restrictions on its adhesive treatment.
As described in Japanese Patent No. 1555, this is carried out by heating to a temperature above the softening point of the resin and applying pressure.

In addition, in the method of the present invention as described above, in an environment where the Sn-plated surface shows yellowing over time, electrolytic chromic acid treatment may be performed before adhering the aluminum foil, if necessary.

The aluminum foil laminated steel sheet manufactured by the method of the present invention as described above has excellent adhesive properties, and due to the presence of aluminum foil, it can be put into practical use as a container material with good corrosion resistance and withstands severe processing (e.g. drawing and ironing). Served.

Example Next, examples of the present invention will be described.

Example 1 Degreasing a low carbon cold rolled steel plate (NaOH2.5%, 80°C,!
OA/dm2X 1 second) and pickling (H2SO+ 10%,
After surface cleaning treatment at room temperature, lOA/d112 x 1 second), Ni plating treatment (NiSOa h8) was applied to one side of the steel plate.
) 120 240 g/min, N i CQ 2 6H
2045g/Nitrogen, H3B0330 gIQ, 50
℃, Ni adhesion amount 120 intestine gets 2) L, Sn plating treatment on the other side (Sn"25g/Q, acid 15g/
Q (H2S 04 conversion), additive 5g/i, 5
0°C, Sn adhesion amount 1150 + mg/112) L, coarse OA acid treatment (Na2Cr2O725g/Q,
Attachment foil (thickness 10 ml) was temporarily attached only to the Ni-coated surface of the steel plate produced by dipping at 45°C for 1 second via an adhesive film (17 to 187 t polypropylene film), and then Crimp (1) Adhesive film crimping temperature 128℃/l Crimp force 2.5 Kg/am2 (2) Foil crimping temperature
158℃/I Crimping force 3 Kg/cm2
(3) After adhesion, the bonding temperature was 175°C7/pressing force was 3 Kz/cm2, and the bonding was water-cooled.

The aluminum foil laminated steel sheet produced under the above conditions was drawn and ironed to form a can with the Sn side facing outward.

As an accelerated test, after filling commercially available beverages (phosphoric acid-based, citric acid-salt-based, citric acid-based, lactic acid-based, malic acid-based) without coating, the amount of Fe eluted after 12 days at 55°C in N2 was measured. was measured. As a result, good results were obtained with an Fe concentration of 0.5 ppm or less.

Example 2 Instead of the Xi plating process of Example 1, the following Or plating was performed.

CrO3200g IQ S042 g/1 45°C C Amount θ011g/112 A laminated steel plate was prepared under the same conditions as in Example 1, and a corrosion resistance test was conducted after drawing and ironing.

The result was a good Fe elution amount of 0.5 ppm.

Comparative Example 1 After degreasing and pickling, one side was immediately Sn-plated (Sn
n adhesion amount on one side 1250+gm2, one side Omg/m2)
.

A laminated steel plate is made from this single-sided Sn-plated steel plate, and the aperture e
Ironing process was performed. The M foil on the inner surface peeled off and the can could not be used as a single can.

Comparative Example 2 Get rid of IT! - Immediately after pickling, both sides were Sn-plated (
Sn+t! Amount: 2 1500 on each side + sg/m21 150 on each side
0 mg/m') - A laminated steel plate was prepared from this double-sided Sn-plated steel plate, and subjected to drawing and ironing. As a result, the M foil on the inner surface of the can peeled off, making it impractical.

Effects of the Invention According to the present invention, the adhesiveness between aluminum foil and steel plate is excellent;
Furthermore, an aluminum foil laminated steel sheet can be obtained that has good workability in severe processing such as drawing and ironing, and has excellent corrosion resistance against the filling contents.

Claims (1)

[Claims] Adhesion amount 100-2000 on one side of the steel plate that becomes the inner surface of the container
Ni plating at mg/m^2 or 50-200mg/m
^2 After applying one layer of Cr plating or two layers of these, apply Sn plating with a coating amount of 1000 mg/m^2 or more to one side of the steel plate, which will be the outer surface of the container on the opposite side, and then apply one or two layers of these plating layers. A method for manufacturing an aluminum foil laminated steel sheet with excellent workability and corrosion resistance, which is characterized by laminating aluminum foil on both sides with an adhesive.