JP3134133B2 - Color film laminated can - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color film laminated can having a resin film layer having a colored ink layer on the surface of a steel plate corresponding to the inner surface of the can via an adhesive layer.

[0002]

2. Description of the Related Art Can containers are filled with beverages such as beer cans, carbonated beverage cans, coffee cans, and the like, and filled with foods containing solids such as fish meat cans, vegetable cans, and snack cans. Currently, it is inevitable to eat. In addition, printing can display the color and beauty of the outer surface of cans as well as enhancing the basic functionality of cans, such as preserving the contents of cans, in order to respond to diversification of values. Various ideas and investigations have been made on the sharpness and the like of the image.

On the other hand, as for the inner surface of the can, conventional painting is still mainly used, and there are some can bodies in which a resin film partially containing a white pigment is laminated. However, recently, regarding the color tone of the inner surface of the can, color matching with the contents has been desired from the viewpoint of improving the image of the can body.
The technology of laminating a film on a steel plate has been around for a long time, and has been studied in the field of cans.

For example, as disclosed in JP-A-62-227642 and JP-A-58-82717,
The prior art mainly deals with two-piece cans such as drawn cans and ironed cans, 18-liter cans, and can lids.
However, these prior examples are aimed at improving corrosion resistance and saving labor in the can-making process, and it is difficult to cope with the color tone of various types of contents with the current coating and lamination of resin films containing white pigments. , From a wide variety of contents
The emergence of a new can that can match the color tone is desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a color film laminated can body that can easily obtain a color tone matching various kinds of contents. It is.

[0006]

The gist of the present invention is as follows. (1) A color film laminated can body , wherein an inner surface of the can has an organic coating layer in the form of an adhesive layer / ink layer / resin film layer from the outermost steel plate side of the can body.

(2) The can body is a three-piece can body,
The color film product according to the item 1, which is a one-piece can or can lid
Layer can body . (3) a resin film layer, a polyester resin film having a thickness of 5 to 30 [mu] m, the ink layer thickness of 2 to 10 [mu] m, the preceding first adhesive layer is characterized in that it is a curable adhesive 0.5~5μm or 3. The color film laminated can according to 2 .

[0008]

The present invention will be described below in detail. The color film laminated can of the present invention is characterized in that the inner surface of the can has an organic coating layer in the form of an adhesive layer / ink layer / resin film layer from the outermost steel plate side of the can body. It is assumed that.

The color film laminated can of the present invention is generally called a two-piece can, in which a can bottom is integrated with a can body, and is usually called a two-piece can. A typical can is formed by drawing. "Draw cans" and "DI cans (Drawn and Irone) formed by drawing and ironing
d cans) ", and a so-called normal three-piece can with a canopy and a canopy wrapped around the body, and an" adhesive can "for joining the can body with an adhesive and a" welding can "for joining the can body with a solution Contains
I do .

[0010] The color film laminated can according to the present invention comprises a can
It is significant that the inner surface has an organic coating layer in the configuration of an adhesive layer / ink layer / resin film layer from the outermost steel plate side of the can body, and the operation of each layer is as follows. . For the purpose of matching the color tone with the contents of the inner surface of the can as in the present invention, the ink layer is basically the minimum necessary layer. This purpose alone can be achieved by printing directly on a steel sheet, but there are many practical difficulties due to restrictions on hygiene due to processing adhesion, retortability, and direct contact with the contents. In addition, although there is no means to apply a top coat with paint on the upper layer of the ink layer, there are also problems such as the need to use a paint that does not develop color and the need for retort properties, etc. It is poor at present.

[0011] According to the present invention , the inner surface of the can is the outermost surface of the can.
A color filter characterized by having an organic coating layer in the form of an adhesive layer / ink layer / resin film layer from the steel plate side
The above-mentioned problem can be solved at the same time by using a multi-layered can body . The resin film layer of the color film laminated steel sheet which is the material of the can body of the present invention 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 touching each other. Since the ink layer is intended for color matching with the contents,
An ink of a color corresponding to the content is printed.

The adhesive layer is required to secure an adhesive strength that can withstand drawing can processing and drawing and ironing processing, and further, depending on the contents, an adhesive strength that can withstand retort processing performed after filling. Next, the color, which is the material of the can body of the present invention ,
-Each layer constituting the film laminated steel sheet will be described. First, the resin film layer will be described.

The resin film layer needs to be a highly transparent film in terms of color tone. In addition, when applied as a body material for three-piece cans, the main body is currently of the adhesive or welding method, but especially in the case of welding cans by the welding method, the welded parts are unpainted and repaired from the point 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, these repair coatings are also baked in a short time from the viewpoint of productivity, and are baked in a short time. Although development is being considered, the temperature is 15
0 ° C or higher, and at the highest temperature, 1
It is heated in 2 to 15 seconds and may reach 280 ° C.
If the melting point of the film is low, the influence of such heat may cause local melting or change of the crystalline state, resulting in a change in color tone.

[0015] Regardless of the three-piece can and two-piece cans, content filling, but the canopy tightening is performed, unless the contents are carbonated beverages, is sterilized or retort treatment at a temperature range of usually 80 to 130 ° C. Done. 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 restricted in terms of heat resistance and water resistance.

In terms of the heat resistance of the film, it is necessary to withstand the baking temperature of the repair coating, but as described above,
Needless to say, it is necessary to apply a resin film suitable for the baking conditions of the repair coating. 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 use a resin film having a water absorption of 1% or less, for example.
When a film having a water absorption of more than 1% is applied, the above-mentioned sterilization treatment and retort treatment undesirably cause corrosion of the base steel sheet. A polyester resin film is a preferred resin film also from the viewpoint of water resistance. Although the film to be applied has been described above, the polyester resin film has a wide range of applicability and is optimal in view of heat resistance, water resistance and transparency.

Further, as the polyester resin film, an oriented crystalline one and an amorphous one can be applied. However, when the polyester resin film is applied to a can body having a high workability, the polyester resin film becomes amorphous in view of workability. 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 is less than 5 μm, if the film is scratched in the can making process, it is not preferable because it causes a reduction in corrosion resistance.
On the other hand, even if it exceeds the upper limit of 30 μm, the effect is saturated in terms of corrosion resistance, which is economically disadvantageous. Preferably 8 to 25 μm
Is good.

The adhesive of the present invention must be selected from those which do not cause wrinkling or peeling of the film due to the baking and sterilization or retort treatment of the above-mentioned repair coating.
Curable adhesives such as epoxy-based adhesives are preferred. The thickness of the adhesive layer is 0.5 to 5 μm. If the thickness is less than 0.5 μm, especially in the case of gravure printing, the adhesive is absorbed into the ink layer, so that the effective adhesive amount is reduced and the adhesive strength is not sufficiently secured. The effect is saturated even if it exceeds 5 μm. Preferably it is 1 to 4 μm. However, as described above, since it is necessary to secure the effective adhesive amount, it goes without saying that there is an optimum amount according to the thickness of the ink layer.

Next, the ink layer will be described. The can of the present invention
The ink layer of the color film laminated steel sheet, which is the material of the body ,
Since the purpose is to match the color tone of the contents with the color tone of the can body, an ink having a color tone suitable for the contents is applied. As a 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 workability.

As the coloring pigment, an inorganic pigment or an organic pigment is used. The ink layer does not directly touch the contents, but it is preferable to use a non-toxic pigment. The thickness of the ink layer is 2 to 10 μm. If the lower limit is less than 2 μm, the concealment is inferior and the color tone may not be obtained depending on the steel plate used. The upper limit of 10 μm is the material of the can body of the present invention described later.
The upper limit of color tone can be obtained for all the color film laminated steel plate is not economical because the color tone saturated even exceed 10 [mu] m.

As a means for printing the ink on the film, a conventional method such as gravure printing is applied. The color of the present invention
-The steel plate that is the base material of the film laminated can body is made of Al, Cr,
This is a surface-treated steel sheet plated with Ni, Sn, or the like, and has a thickness of 0.10 to 0.30 mm. Other than the Al-plated steel sheets, they are currently used as steel sheets for three-piece cans and two-piece cans.

Specifically, the amount of Sn adhesion on one side is 0.5
~ 3.0 g / m ² plating, Sn-plated steel sheet subjected to chemical conversion treatment, 0.3-2.0 g / m ² as Ni adhesion amount on one side
⁽²⁾ After plating, a Ni-plated steel sheet subjected to a chemical conversion treatment, and Sn and Ni adhesion amounts on one side of 0.5 to 2.0 g /
m ² , 0.1-0.5 g / m ² plated with Ni and Sn in this order, and then subjected to a chemical conversion treatment.
r Adhesion amount 50 to 120 mg / m ² , Cr oxide 5 to 20 m
g / m ² of normal TFS (Tin Free Stee)
1) chromium, chromate-treated steel plate and the like.

A method of laminating a film on these steel plates
As a dry lamination method in which a film on which ink is printed in advance is laminated on a steel plate coated with an adhesive, or after printing an ink on the film in advance, an adhesive is applied to the ink layer surface, and the dried film is dried. how such there be laminated to heated steel sheet is, the steel sheet which the film is laminated,
Lamination is possible with both cut steel sheets and coiled steel sheets.

Next, the can of the present invention will be described in more detail . The can body of the present invention is applied to a body of a three-piece can, a two-piece can, a can lid and the like. When applied to the body of a three-piece can, the film is laminated to the size of the desired can body height in the direction of the can body height, but is slightly smaller than the circumferential size in the circumferential direction of the can body. And has a non-laminated portion. The non-laminated portion is a wrapping margin in the case of a cylinder, ie, an adhesive portion in the case of an adhesive can, and a welded portion in the case of a welded can.

As described above, the wrapping may be performed with an adhesive or by welding. In the case of a two-piece can, a drawn can obtained by drawing and a drawn ironed can (called “Drawn”) that combines drawing and ironing
and Ironed Can; DI can).

In the case of a drawn can, a multistage drawing is possible,
If the drawing ratio is large, the film may be peeled off at the interface between the ink layer and the film. In the case of a drawn and ironed can, if the ironing rate is high, the film itself will crack and the corrosion resistance will be poor, so it is desirable to control the crystal state last. Also, a drawn can formed by performing a stretching process on a can wall at the same time as the drawing process is applied.

The can lid is formed by pressing,
On all lids except EOE (Easy Open End)
The configuration of the color film laminated can of the present invention is applied.
Hereinafter, specifically showing an aspect of the present invention through examples.

[0029]

Example 1 A 4 μm gravure print was applied to a 10 μm-thick biaxially stretched polyester film so that the color tone became brown, and after drying, a urethane-based adhesive was applied to the ink layer surface in a dry thickness of 2.5 μm.
Coated (film 1).

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

The thus obtained color film laminated steel sheet is
Two-stage drawing was performed so that the color film lamination surface was the inner surface of the can, and a drawn can having a drawing ratio of 2.0 was formed. The obtained squeezed cans had no peeling of the film in both the cans of the film 1 and the can of the film 2, and good cans were obtained. Further, when a retort test was carried out at 125 ° C. for 30 minutes in a 3% saline solution, no peeling of the film and no rust occurred in the cans of the film 1 and the can of the film 2, and no change in color tone was observed.

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

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

The obtained squeezed can did not peel off the film in both the can of Film 3 and the can of Film 4, and a good can was obtained. Further, when a retort test was carried out in a 3% saline solution at 125 ° C. for 30 minutes, no peeling of the film and no rust occurred in the film 3 and film 4 cans, 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 press forming to form a can lid. As for the obtained can lid, a good can lid was obtained without peeling of the film on both the can lid of the film 1 and the can lid of the film 2.

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

The color film of the film 5 thus obtained was heated to 190 ° C. at a sheet temperature of a single-sided TFS treatment having a thickness of 0.28 mm and a TFS of a steel sheet having a Sn adhesion amount of 3 g / m ^{2 on} the other side.
After laminating on the treated surface by the thermocompression bonding method, after another 10 seconds, post-heating was performed so that the plate temperature became 250 ° C., followed by rapid cooling to break the oriented crystallinity of the polyester resin film.
The color film laminated steel sheet thus obtained was subjected to DI processing at an ironing rate of 30% so that the color film laminated surface was the inner surface of the can to form a DI can.

The obtained DI can was free of film peeling and a good can was obtained. Further, when a retort test was carried out in a 3% saline solution at 125 ° C. for 30 minutes, no peeling of the film and no rusting occurred, and no change in color tone was observed. Comparative Example A 1.5 μm gravure print was applied to a biaxially stretched polyester film having a thickness of 10 μm so that the color became brown, and after drying, a urethane-based adhesive was applied to the ink layer surface in a dry thickness of 2.5 μm.
μm was applied (film 6).

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

The color film laminated steel sheet obtained from the film 6 had a dull color tone and had an unfavorable appearance. The color film laminated steel sheet obtained from the film 7 had a good color tone, but the film was peeled off by drawing at a drawing ratio of 1.8. Although can lid molding was possible, when the can lid was subjected to a retort test at 125 ° C. for 30 minutes with 3% saline, film peeling occurred.

[0041]

As described above, the color film laminated can obtained by the present invention can match the color of the inner surface of the can with the color of various contents by changing the printing ink. Therefore, it is possible to sufficiently respond to recent consumer demands, and its social significance is large.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshinori Katayama 1-1, Tobata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Yawata Works (56) References JP-A-4-57747 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 15/08 B65D 1/12 B65D 85/72

Claims (3)

(57) [Claims] 1. A color film laminated can having an inner surface of an can having an organic coating layer in the form of an adhesive layer / ink layer / resin film layer from the outermost steel plate side of the can. 2. The can body is a three-piece can body,
2. The color film laminate according to claim 1, which is a base can or a can lid.
Can body . 3. The resin film layer is a polyester resin film having a thickness of 5 to 30 μm and an ink layer having a thickness of 2 to 10 μm.
3. The color film laminated can according to claim 1, wherein the adhesive layer is a curable adhesive having a thickness of 0.5 to 5 μm. 4.