JPH0655687A - Color-film laminated steel plate for vessel and can body - Google Patents

Abstract

PURPOSE:To improve an image as a can body by matching the color tone of the internal surface of a can with the color tone of content. CONSTITUTION:A steel plate for a vessel and a can body have an organic film layer by the constitution of an adhesive layer/an ink layer/a resin film layer from the steel plate side on the surface of the steel plate corresponding to the internal surface of a can. A polyester resin film in thickness of 5-30mum is used as a resin film, the ink layer is 2-10mum thick, and the adhesive layer is 0.5-5mum thick and curing type adhesives are applied. A drawn can, a drawn sheared can, a three-piece can, a can cover, etc., are applied as the can body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate and a can body to be used for a can container, and more particularly to a container having a resin film layer having a coloring ink on the surface of the steel plate corresponding to the inner surface of the can via an adhesive layer. The present invention relates to a steel sheet for use and a can body obtained from the steel sheet.

[0002]

2. Description of the Related Art Can containers are filled with drinks such as beer cans, carbonated drinks cans, coffee cans, and foods containing solids such as fish cans, vegetable cans, and snacks cans. , At present, it has become a part of the diet. Moreover, the cans of recent years are not only more sophisticated in their basic functionality, such as storing their contents, but also can be used to display the color and beauty of the outer surface of the can and to display a trademark in order to respond to the diversification of values. Various ideas and studies have been made on the image clarity and the like.

On the other hand, with respect to the inner surface of the can, the conventional coating is still main, and there is a can body to which a resin film containing a part of a white pigment is laminated. However, recently, with regard to the color tone of the inner surface of the can, color tone matching with the contents has been desired from the viewpoint of improving the image of the can body.
The technology for laminating a film on a steel plate has been around for a long time, and it has been studied in the field of can containers.

For example, as seen in JP-A-62-227642 and JP-A-58-82717,
The prior art mainly includes two-piece cans such as squeezed cans and ironing cans, 18-liter cans, and can lids.
However, these precedent examples are aimed at improving corrosion resistance and labor saving in the can manufacturing process, and it is difficult to apply the current painting or laminating resin films containing white pigments to cope with the color tone of a wide variety of contents. Therefore, the advent of new container materials is desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object of the present invention is to provide a material for a container which can easily obtain a color tone matching a wide variety of contents. .

[0006]

The subject matter of the present invention is as follows. (1) A color film laminated steel sheet for a container, which has an organic film layer having a constitution of an adhesive layer / ink layer / resin film layer from the steel sheet side on a steel sheet surface corresponding to the inner surface of a can.

(2) The resin film layer has a thickness of 5 to 30.
μm polyester resin film with ink layer thickness of 2
10. The color film laminated steel sheet for containers according to item 1, which is a curable adhesive having a thickness of 10 μm and an adhesive layer of 0.5 to 5 μm. (3) A color film laminated can body characterized in that the inner surface of the can has an organic film layer in a constitution of an adhesive layer / ink layer / resin film layer from the steel plate side.

[0008]

The present invention will be described in detail below. The structure of the present invention is one in which a resin film having a preprinted ink layer is laminated via an adhesive layer on the surface of a steel plate corresponding to the inner surface of a can. Steel sheets for containers laminated in the order of ink layer / resin film layer,
And a can body obtained from the steel plate.

The steel sheet of the present invention is usually called a two-piece can in which a can bottom and a can body are integrated and a canopy is fastened, and a typical can is a "drawing can" formed by drawing. "DI can (Draw and ironed can)" that is formed by squeezing and squeezing, and what is usually called a three-piece can in which the canopy and canopy are wrapped around the body. It is applied to "welding cans", in which can bodies are joined by welding, and can lids.

In the steel sheet of the present invention, it is significant to use a can having a multilayer organic film structure, and the action of each layer is as follows. For the purpose of color tone matching with the contents on the surface of the steel sheet as in the present invention, the ink layer is basically the minimum necessary layer. If this is the only purpose, it can be achieved by printing directly on the steel plate, but processing adhesion, retortability, and because it directly touches the contents, it is restricted in hygiene and practically difficult points. Many. In addition, although there is no way to apply a top coat of paint to the upper layer of the ink layer, there are problems such as the fact that it must be a paint that does not develop color and that it also requires retortability. The current situation is poor sex.

If the resin film is printed as in the present invention and the resin film is laminated so as to touch the contents, the above problems can be solved at the same time. Therefore, the resin film layer is a carrier film for holding the ink layer, and has a role of a barrier layer for preventing the ink and the contents from directly contacting each other. Since the ink layer is for the purpose of matching the color tone with the content, the ink having a color tone corresponding to the content is printed.

[0012] The adhesive layer is necessary to secure an adhesive force that can withstand the squeezing process and the squeezing and ironing process, and depending on the content, an adhesive force that can withstand the retort treatment performed after filling. Next, each layer applied to the present invention will be described. First, the film applied to the present invention will be described.

The resin film applied to the present invention must be a highly transparent film from the viewpoint of color tone. In addition, when applied as a can body material for three-piece cans, currently the main body is the bonding method or welding method, but especially for welding cans using the welding method, the welded part is unpainted and repaired from the viewpoint of corrosion resistance. Painting is required.

In the current can-making process, various repair coatings are performed depending on the contents to be filled. However, this repair coating is also in the direction of baking for a short time from the point of view of productivity, and it is difficult to remove it from the viewpoint of paint. Although development is being considered, it is 15
If the temperature is higher than 0 ℃ and the highest temperature
It has been said that it heats up in 2 to 15 seconds and reaches 280 ° C. The influence of such heat causes a local melting or a change in crystal state when the melting point of the film is low, and causes a change in color tone.

In addition, regardless of whether it is a three-piece can or a two-piece can, the contents are filled and canopy-wrapped. However, unless the contents are carbonated drinks, sterilization or retort treatment is usually performed in the temperature range of 80 to 130 ° C. Done. Also at this time, if the crystal structure of the resin film changes, the color tone changes. Therefore, the film applied to the present invention is limited in heat resistance and water resistance.

From the viewpoint of the heat resistance of the film, it is necessary to endure the baking temperature of the repair coating, but as mentioned above, it is necessary to apply a resin film suitable for the baking conditions of the repair coating. Needless to say, in the case of a polyester resin film, a high melting point of about 265 ° C. can be obtained by selecting an alcohol component and an acid component,
Since the heat resistance can be ensured, the applicability is wide and preferable.

Next, regarding water resistance, it is desirable to apply a resin film having a water absorption of 1% or less.
When a film having a water absorption rate of more than 100% is applied, the sterilization treatment and the retort treatment described above undesirably cause corrosion of the base steel sheet. The polyester resin film is a preferable resin film from the viewpoint of water resistance. Although the film to be applied has been described above, the polyester resin film has wide applicability and is most suitable in terms of heat resistance, water resistance and transparency.

Further, the polyester resin film may be oriented crystalline or amorphized, but when applied to a can body having a high degree of processing, it is amorphized in terms of processability. It may be more advantageous. Next, the thickness of the resin film applied to the present invention will be described. In the present invention, a resin film having a thickness of 5 to 30 μm is applied. If the lower limit value is less than 5 μm, when the film is scratched in the can making process, it is not preferable because it causes a decrease in corrosion resistance.
On the other hand, even if the upper limit of 30 μm is exceeded, the effect is saturated in terms of corrosion resistance, which is economically disadvantageous. Preferably 8 to 25 μm
Is good.

As the adhesive of the present invention, it is necessary to select one that does not cause wrinkles or film peeling due to the above-mentioned baking and sterilization treatment of repair coating or retort treatment. From such a meaning, urethane type, polyester type,
A curable adhesive such as an epoxy type adhesive is preferable. The thickness of the adhesive layer is 0.5 to 5 μm. If the thickness is less than 0.5 μm, the amount of effective adhesive decreases because the adhesive is absorbed in the ink layer, especially in the case of gravure printing, and the adhesive strength is not sufficiently secured. Further, the effect is saturated even if it exceeds 5 μm. It is preferably 1 to 4 μm. However, as described above, it is needless to say that there is an optimum amount according to the thickness of the ink layer because it is necessary to secure the effective adhesive amount.

Next, the ink layer will be described. Since the ink layer applied to the present invention is intended to match the color tone of the content with the color tone of the can body, it goes without saying that an ink having a color tone suitable for the content is applied. As the binder of the ink, a printing ink containing a synthetic resin such as an acrylic resin or a urethane resin as a main binder is preferable from the viewpoint of heat resistance and processability.

Inorganic pigments and organic pigments are used as the coloring pigments, but the ink layer does not directly touch the contents, but it is better to apply non-toxic pigments. The thickness of the ink layer is 2 to 10 μm. If the lower limit is less than 2 μm, the hiding is poor and the color tone may not appear depending on the steel plate used. The upper limit value of 10 μm is an upper limit at which a color tone is obtained for all steel sheets applied in the present invention described later,
Even if it exceeds 10 μm, it is not economical because the color tone is saturated.

As the ink printing means on the film, a commonly used method such as gravure printing is applied. The steel plate applied to the present invention is a surface-treated steel plate plated with Al, Cr, Ni, Sn or the like, and has a plate thickness of 0.10 to 0.30 mm. Except for the Al-plated steel sheet, it is currently used as a steel sheet for three-piece cans and two-piece cans.

Specifically, the amount of Sn deposited on one surface is 0.5.
~ 3.0 g / m ² Sn-plated steel plate after chemical conversion treatment, 0.3 to 2.0 g / m as Ni adhesion amount on one surface
² After plating, Ni-plated steel sheet subjected to chemical conversion treatment, Sn and Ni adhesion amount on one side of 0.5 to 2.0 g /
m ² and 0.1 to 0.5 g / m ² are plated in the order Ni and Sn, and then Sn / Ni-plated steel sheet subjected to chemical conversion treatment, metal C
r Adhesion amount 50 to 120 mg / m ² , Cr oxide 5 to 20 m
Normal TFS (Tin Free Stage) of g / m ²
1) Chromium and chromate treated steel sheets.

The steel sheet of the present invention is formed by a dry lamination method in which a film on which ink is printed in advance is laminated on a steel sheet on which an adhesive is applied, or after ink is printed on the film in advance, an adhesive is applied on the ink layer surface. , A method of laminating a dried film on a heated steel plate. Further, the film laminated steel sheet of the present invention can be laminated from a cut sheet steel sheet or a coiled steel sheet.

Next, the can body applied to the present invention will be described. The can body of the present invention is applied to a body part of a three-piece can, a two-piece can, a can lid, and the like. When applied to the barrel of a three-piece can, the film is laminated to the desired can size in the can height, but in the circumferential direction of the can body it is slightly smaller than the circumferential size. It is laminated on the steel sheet with a narrow width and has a non-laminated portion. This non-laminated part is the lap cost when making a cylinder, that is, the adhesive part in the case of an adhesive can,
In the case of a welding can, it becomes the welded part.

The lapping means may be performed with an adhesive as described above, or may be performed with welding. In the case of a two-piece can, a drawn can obtained by drawing and a drawn and ironed can obtained by combining drawing and ironing (commonly known as Drawn
and Ironed Can; DI can).

In the case of a squeezing can, a multi-stage squeezing is possible,
If the drawing ratio is large, peeling may occur at the interface between the ink layer and the film, so care must be taken. In the case of a squeezed ironing can, if the ironing ratio is high, the film itself is cracked and the corrosion resistance is inferior, so it is desirable to control the crystalline state last. Further, a drawn can in which a can wall is stretched and molded at the same time as drawing is applied.

The can lid is formed by pressing,
For all lids except EOE (Easy Open End),
The invention applies. Hereinafter, the effects of the present invention will be specifically shown in Examples.

[0029]

【Example】

Example 1 A biaxially stretched polyester film having a thickness of 10 μm was gravure-printed so as to have a brown color tone of 4 μm, and a urethane adhesive was dried on the ink layer surface to a thickness of 2.5 μm.
It was applied (film 1).

On a biaxially stretched polyester film having a thickness of 10 μm, 3 μm gravure printing was performed so that the color tone was gray, and after drying, a urethane adhesive was applied to the ink layer surface at a dry thickness of 2.5 μm (film 2). The color films of Film 1 and Film 2 thus obtained were heated at a plate temperature of 190.
It was laminated by a thermocompression bonding method on a TFS (chromium, chromate steel plate) having a plate thickness of 0.20 mm heated to 0 ° C.

The color film laminated steel sheet thus obtained is
A two-stage drawing process was performed so that the laminated surface of the color film was the inner surface of the can, and a drawn can having a draw ratio of 2.0 was formed. The squeezed can thus obtained was free from film peeling in both the film 1 can and the film 2 can, and a good can body was obtained. Further, when a retort test was carried out with a 3% saline solution at 125 ° C. for 30 minutes, neither film 1 can nor film 2 can was peeled off, no rust was generated, and no change in color tone was observed.

Example 2 A biaxially stretched polyester film having a thickness of 20 μm was gravure-printed with 4.5 μm so that the color tone was pink, and after drying, an epoxy adhesive was applied to the ink layer surface in a dry thickness of 2 μm (Film 3 ). 6μm on a 20μm thick biaxially stretched polyester film so that the color tone is gold
After gravure printing and drying, an epoxy adhesive was applied to the ink layer surface in a dry thickness of 2 μm (film 4).

The color films of films 3 and 4 thus obtained were heated to 200 ° C. at a plate temperature of 0.2.
4 mm Sn deposition amount 1 g / m ² , Ni deposit 0.3g /
It was laminated by a thermocompression bonding method on a steel sheet that had been subjected to chromate treatment after Sn / Ni plating of m ² . The color film laminated steel sheet thus obtained was molded into a drawn and ironed can having a drawing ratio of 1.8 and an ironing ratio of 20% with the color film laminated surface being the inner surface of the can.

The squeezed can thus obtained was free from film peeling in both the film 3 can and the film 4 can, and a good can body was obtained. Further, when a retort test was carried out with a 3% saline solution at 125 ° C. for 30 minutes, neither film 3 cans nor film 4 cans were free from film peeling and rusting, and no change in color tone was observed.

Example 3 The color film laminated steel sheets of Film 1 and Film 2 used in Example 1 were subjected to can lid forming by pressing. In the obtained can lid, neither the can lid of the film 1 nor the can lid of the film 2 was a good can lid without film peeling.

Further, when a retort test was carried out with a 3% saline solution at 125 ° C. for 30 minutes, no film peeling or rusting occurred on the can lid of film 1 and the can lid of film 2, and no change in color tone was observed. It was Example 4 A biaxially stretched polyester film having a thickness of 25 μm was subjected to 6.5 μm gravure printing so that the color tone was brown, and after drying, a urethane adhesive was dried on the ink layer surface to a thickness of 3 μm.
It was applied (film 5).

The color film of the thus obtained film 5 was heated to 190 ° C. at a plate temperature of 0.28 mm on one side and subjected to TFS treatment on one side and Sn on the other side of 3 g / m ² of TFS of a steel sheet.
After laminating on the treated surface by thermocompression bonding, after 10 seconds, it was post-heated to a plate temperature of 250 ° C. and rapidly cooled to destroy the oriented crystallinity of the polyester resin film.
The color film laminated steel sheet thus obtained was subjected to DI processing with an ironing rate of 30% so that the color film laminated surface was the inner surface of the can, and a DI can was molded.

The resulting DI can had a good can body without peeling of the film. Further, when a retort test was carried out with a 3% saline solution at 125 ° C. for 30 minutes, no film peeling or rusting occurred and no change in color tone was observed. Comparative Example 1.5 μm gravure printing was performed on a biaxially stretched polyester film having a thickness of 10 μm so that the color tone was brown, and after drying, a urethane adhesive was applied to the ink layer surface at a dry thickness of 2.5.
μm was applied (film 6).

A biaxially stretched polyester film having a thickness of 10 μm was gravure-printed with a thickness of 3 μm so that the color tone was gray, and after drying, a urethane adhesive was applied to the ink layer surface in a dry thickness of 0.3 μm (film 7). The color films of Film 6 and Film 7 thus obtained were heated at a plate temperature of 190.
It was laminated by a thermocompression bonding method on a TFS (chromium, chromate steel plate) having a plate thickness of 0.20 mm heated to 0 ° C.

The color film laminated steel sheet obtained from the film 6 had a dull color tone, and the appearance was not preferable. The color film laminated steel sheet obtained from the film 7 had a good color tone, but film peeling occurred in the drawing process with a drawing ratio of 1.8. Although can lid molding was possible, film peeling occurred when the can lid was subjected to a retort test with a 3% saline solution at 125 ° C for 30 minutes.

[0041]

As described above, in the color film laminated steel sheet obtained in the present invention, the color tone of the inner surface of the can can be matched with the color tone of various contents by changing the printing ink. Therefore, it is possible to sufficiently meet the recent demands of consumers, and its social significance is great.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshinori Katayama 1-1 Tobahata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka New Nippon Steel Corporation Yawata Works

Claims (3)

[Claims] 1. A color film laminated steel sheet for a container, comprising an organic film layer having a constitution of an adhesive layer / ink layer / resin film layer from a steel sheet side on a steel sheet surface corresponding to an inner surface of a can. 2. The resin film layer is a polyester resin film having a thickness of 5 to 30 μm and the ink layer has a thickness of 2 to 10
The color film laminated steel sheet for containers according to claim 1, wherein the color film laminated steel sheet is a curable adhesive having a thickness of 0.5 μm and an adhesive layer of 0.5 to 5 μm. 3. A color film laminated can body characterized in that an inner surface of the can has an organic film layer in a constitution of an adhesive layer / ink layer / resin film layer from the steel plate side.