JP3591064B2 - Metal can body - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal can body used for an aerosol can or a beverage can, and more specifically, a necking process, a flange process, a post-process such as a curl process, and a printed synthetic resin film. The present invention relates to a metal can body whose ends are not damaged.
[0002]
[Prior art]
In the case of a metal can body, particularly a two-piece can made of aluminum or the like, it has been required to perform high-grade printing on the can.
Conventionally, in order to perform high-grade printing, it has been proposed in Japanese Patent Application Laid-Open No. 4-57747 or the like to bond a high-quality printed sheet-like film to the outer peripheral surface of a two-piece can.
The can body to which the film is bonded is subjected to a post-processing such as a necking process, a flange process, or a curl process.
[0003]
[Problems to be solved by the invention]
However, during the post-processing such as the necking process, the end of the film on the opening side of the can body is subjected to the processing load, so that the end of the film is damaged and the film and the can body are separated. There is a problem.
In addition, cleaning of metal cans, retort sterilization, pasteurizer sterilization, or hot water inspection in aerosol cans, water and hot water penetrate from between the edge of the film and the metal can, causing film peeling and metal corrosion. And impair the appearance.
Further, when the can body is made of aluminum, the metal of the can body adheres to the tool during the necking process or the like, so that continuous production cannot be performed.
[0004]
[Object of the invention]
Therefore, an object of the present invention is to provide a metal can body used for an aerosol can or a beverage can, which does not damage the ends of the synthetic resin film even after post-processing such as necking. .
[0005]
[Means for Solving the Problems]
The present invention has been proposed in order to achieve the above object, and has the following features.
That is, according to the present invention, the synthetic resin film having the printed layer and the adhesive layer formed on one surface is located at a position where the upper end of the synthetic resin film exposes the opening end of the can body. A metal adhered to the can body via the adhesive in a state, and at least a portion from an opening end of the can body to a synthetic resin film in a portion to be subjected to post-processing is covered with a protective coating. A can body is provided.
[0008]
Further, according to the present invention, there is provided a metal can body in which all portions including an upper end portion, a lower end portion, and both ends in a circumferential direction of a synthetic resin film are covered with a protective coating.
[0009]
Further, according to the present invention, a synthetic resin film having a printed layer formed on one surface and an adhesive layer formed on the other surface is formed by forming an upper end portion of the synthetic resin film at an opening end portion of a can body. Is adhered to the can body in a position where the resin film is exposed, and the upper and lower ends of the synthetic resin film and the printing layer, including both ends in the circumferential direction, are covered with a protective coating. A metal can body is provided.
[0010]
Further, according to the present invention, in the metal can body according to any one of claims 1 to 3, the opening end of the aluminum can body including the end face and the upper end of the synthetic resin film are covered with a protective coating. A coated metal can body is provided.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
In the metal can body according to the first aspect of the present invention, a synthetic resin film having a printed layer and an adhesive layer formed on one surface is exposed at an upper end portion of the open end portion of the can body via an adhesive. At least a portion of the synthetic resin film to be subjected to post-processing from the opening end of the can body is covered with the protective film .
Therefore, the whole synthetic resin film is prevented from being damaged when subjected to post-processing in which necking or the like, the upper end portion of the synthetic resin film nor or peeled off from the can barrel.
[0014]
In the metal can body according to the second aspect of the present invention, in the metal can body according to the first aspect, the synthetic resin film is entirely covered with a protective coating, including the upper end, the lower end, and both ends in the circumferential direction. Therefore, water or hot water does not enter between the synthetic resin film and the can body, and peeling of the film and corrosion of metal do not occur.
[0015]
In the metal can body according to the third aspect of the present invention, a synthetic resin film having a printed layer formed on one surface and an adhesive layer formed on the other surface is bonded to the can body via the adhesive layer. The upper end of the synthetic resin film is bonded to a position where the open end of the can body is exposed, and the upper end, the lower end, and all the circumferential ends of the synthetic resin film are included. And the printing layer are covered with a protective coating.
[0016]
Therefore, similarly to the first or second aspect of the invention, the end of the synthetic resin film is prevented from being damaged, and the end of the synthetic resin film does not peel off from the can body.
In addition, according to the third aspect of the present invention, even if the printing layer is not covered with the synthetic resin film, the printing layer is covered with the protective film, so that the printing layer is not damaged.
[0017]
In the metal can body according to the fourth aspect of the present invention, in the metal can body according to any one of the first to third aspects, the opening end of the aluminum can body including the end face and the upper end of the synthetic resin film are covered with a protective coating. A metal can body is provided.
Therefore, similarly to the first to third aspects of the present invention, the end of the synthetic resin film is prevented from being damaged, and the end of the synthetic resin film does not peel from the can body.
Moreover, in the invention of claim 4 , since the end surface of the open end of the aluminum can body is covered with a protective coating, the metal can be applied to a metal processing tool at the time of post-processing such as necking generated by an aluminum material. Adhesion is prevented.
[0018]
In the present invention, as a material of the synthetic resin film, a polyester resin such as a polyethylene terephthalate resin or a polybutylene terephthalate resin, a copolymerized polyester resin formed of a copolymer of polyethylene terephthalate and isophthalic acid, polyethylene, polypropylene, etc. Polyolefin-based resins, polyamide-based resins, or mixtures and laminates of the above resins can be exemplified. Particularly, the use of a biaxially-rolled film made of a polyester-based resin such as polyethylene terephthalate resin is preferred for heat resistance and transparency. It is preferable in terms of workability, toughness, gloss, and cost. The thickness of the synthetic resin film is preferably 5 to 25 μm, particularly preferably 8 to 15 μm, from the viewpoint of necking workability, scratch resistance and workability.
[0019]
Examples of the material for the protective coating include known finish varnishes of acrylic, polyester, epoxy, and alkyd resin paints commonly used for metal cans. It is applied in consideration of the properties and scratch resistance.
The thickness of the protective coating is preferably 1 to 10 μm, particularly preferably 2 to 6 μm, from the viewpoint of necking workability and scratch resistance.
In addition, you may use an ultraviolet curing type paint.
[0020]
Examples of the adhesive include a thermoplastic resin and a thermosetting resin. In particular, the use of a thermosetting resin is preferable in terms of necking workability and heat resistance.
The thermosetting resin may be a polyester, urethane, epoxy, acrylic, amino or the like alone or a composition obtained by adding a curing agent to these, and a composition obtained by mixing two or more resins. Apply in consideration of the adhesion to the material of the body.
Further, in the case where the color tone of the metal can body is concealed and the print quality is required, an adhesive containing various pigments may be applied.
[0021]
Examples of the method of forming the printing layer include gravure printing and flexographic printing. In particular, the method of forming the printing layer by gravure printing is characterized in that the image quality is clear and a high-quality printing layer is obtained. preferable.
As the ink, a mixture of polyurethane, a vinyl chloride-vinyl acetate copolymer and a homopolymer thereof, or a mixture obtained by adding a curing agent such as isocyanate to these resins is used.
[0022]
Further, examples of the material of the metal can body include aluminum, tin-plated steel plate, tin-free steel, tin-nickel-plated steel plate, a coated plate obtained by coating an organic coating on these, a laminate material obtained by laminating a synthetic resin film, and the like. .
In addition, as a method for forming a can body, a method for manufacturing a two-piece can, a monoblock can such as an impact extrusion method, a draw forming method, a draw-ironing method, or a method of joining side seams by welding, bonding, or the like. A method of manufacturing a three-piece can to be manufactured can be exemplified.
[0023]
In the first to third aspects of the present invention, the position where the synthetic resin film is adhered may be any position where the vicinity of the opening of the can body is exposed. When the can lid is mounted on the metal can body, it is preferable to set the position so that the entire exposed portion of the metal can body is hidden from the viewpoint of improving the appearance.
[0024]
【Example】
Hereinafter, the present invention will be described by way of examples with reference to the drawings.
[0025]
< Reference example >
FIG. 1 is a sectional view of a two-piece metal can body. Although only a part of the cross section of the two-piece metal can body is shown in FIG. 1, it is symmetrical about the center line C. In FIG. 1, a two-piece metal can body 10 has an aluminum can body 12 formed by draw-ironing, and the can body 12 has a bottom 12A at one end in the axial direction (vertical direction in FIG. 1). The other end in the vertical direction is an opening 12B.
[0026]
A synthetic resin film 14 is provided on the outer periphery of the can body 12 along the entire circumferential direction. A printing layer 16 is formed on the synthetic resin film 14 by gravure printing, and an adhesive layer 17 is formed on the printing layer 16. The synthetic resin film 14 on which the printing layer 16 is formed is adhered to the entire outer peripheral surface of the can body 12 by the adhesive layer 17, and both ends in the circumferential direction of the synthetic resin film 14 on which the printing layer 16 is formed. Are layered on top of each other. In this embodiment, as the material of the adhesive layer 17, a composition composed of three types of acrylic-, epoxy-, and amino-based resins is used. In this embodiment, gravure printing is employed as a method for forming the print layer 16.
[0027]
The synthetic resin film 14 is adhered to the end surface 12C of the opening end 12B of the can body 12 with a space L therebetween. In this embodiment, the interval L is set to 1 mm. This interval L is set to a dimension that can be hidden when a can lid (not shown) is wound around the open end 12B of the two-piece metal can body 10.
[0028]
A protective film 20 is formed on the surface of the synthetic resin film 14 opposite to the surface on which the print layer 16 is formed. As shown in FIG. 1, the protective coating 20 is formed only on the upper end 14A of the synthetic resin film 14 from the end face 12C of the open end 12B of the can body 12. Further, the protective coating 20 is formed on the entire circumferential direction of the can body 12 to which the synthetic resin film 14 is adhered. In addition, in this reference example, a composition composed of three types of polyester, acrylic, and amino is used as the protective coating 20.
[0029]
Hereinafter, a brief description will be made on a method of two-piece can body 10 according to the present embodiment.
The can body 12 having a desired shape is formed by drawing-ironing or the like. On the other hand, a printing layer 16 is formed on one surface of the synthetic resin film 14 by gravure printing, an adhesive layer 17 is formed on the printing layer 16, and the adhesive layer 17 is dried. Next, the synthetic resin film 14 is formed in a film shape whose upper direction in FIG. 1 (direction orthogonal to the circumferential direction of the synthetic resin film 14) is shorter than the vertical dimension of the can body 12.
This synthetic resin film 14 is cut slightly longer than the circumferential length of the can body 12, that is, in a state where the overlap of both ends of the synthetic resin film 14 is secured. In this case, the overlapping length is set to 5 mm or less in terms of appearance and cost.
[0030]
Next, the can body 12 is heated by high-frequency induction heating, and the synthetic resin film 14 is brought into contact with the outer peripheral surface of the can body 12 from the side of the adhesive layer 17. Glue along. A protective coating 20 is applied to the entire circumferential direction from the end face 12C of the open end 12B of the can body 12 after bonding to the upper end 14A of the synthetic resin film 14, then bake-hardened, and then subjected to necking. Then, a two-piece can body 10 is obtained.
[0031]
<Example 1 >
FIG. 2 is an embodiment using a can body 12 similar to the above-described reference example . As shown in FIG. 2, post-processing such as necking is performed from an end surface 12C of an open end 12B of the can body 12. This is a two-piece metal can body 10 in which a protective coating 20 is formed only on a portion of the synthetic resin film 14, and other configurations are the same as those of the reference example .
[0032]
<Example 2 >
FIG. 3 shows another embodiment using the same can body 12 as the above-described reference example . As shown in FIG. 3, the entire outer surface of the synthetic resin film 14 extends from the end face 12C of the open end 12B of the can body 12 to the outside. This is an embodiment in which the protective film 20 is continuously formed over the lower end portion 12D of the can body 12 through the protective film 20. The protective coating 20 is formed along the entire surface of the synthetic resin film 14 in the circumferential direction.
[0033]
As described above, the two-piece can body 10 configured as described above includes the end face 12C of the open end 12B of the can body 12, the upper end 14A of the synthetic resin film 14, the lower end 12D of the can body 12, and the synthetic resin film 14. The lower end portion 14B and the circumferential end portions of the synthetic resin film 14 adhered to the can body 12 are covered with protective coatings 20, and the end surface 12C of the can body 12 including the end surface and the entire synthetic resin film 14 are protected. It is covered with the coating 20.
In Examples 1 and 2 , the adhesive layer 17 may contain a pigment such as white or pearl in order to improve the color tone of the print layer 16.
[0034]
<Example 3 >
FIG. 4 shows another embodiment using the same can body 12 as in the above-described second embodiment. As shown in FIG. 4, a printing layer is formed on the surface of the synthetic resin film 14 on the side opposite to the can body 12 side. 16 is formed.
Then, also in this embodiment, the second embodiment and the same, the upper end portion 14A, a lower end portion 12D and the synthetic resin film 14 of the can barrel 12 and the end face 12C of the opening end portion 12B of the barrel 12 synthetic resin film 14 The lower end 14B of the synthetic resin film 14 adhered to the can body 12 is covered with protective coatings 20 at both ends in the circumferential direction, and the open end 12B of the can body 12 including the end face 12C and the synthetic resin film 14 are all covered. Is covered with a protective film 20.
Also in Example 3 of FIG. 4, for improving the color tone of the printing layer 16, the synthetic resin film 14, the white adhesive layer 17 may contain a content of pearl and the like.
[0035]
Further, in the first to third embodiments, the end face 12C of the open end 12A of the aluminum can body 12 is covered with the protective coating from the viewpoint of the adhesion of the metal material to the tool in the neck-in processing or the like in the subsequent step. However, when a tin-plated steel plate, tin-free steel, or tin-nickel-plated steel plate is used as a material for the metal can body of the can body 12, it is not always necessary to cover the end face 12C with a protective coating.
Further, in the first to third embodiments, both ends in the circumferential direction of the synthetic resin film 14 are layered, but they may be spaced apart without being overlapped.
[0036]
【The invention's effect】
According to the present invention, necking the can body, without be subjected to post-processing such as flanging or curling damage synthetic resin film, the film is no peeling child from the can barrel. Furthermore, there is no need to use a large amount of paint for forming a protective film, and there is no need to heat the entire can body when the paint is cured. Further, since the film does not peel off as described above, the film has excellent retort resistance.
Further, according to the invention of claim 2 , water or hot water does not enter between the synthetic resin film and the can body, and peeling of the film and corrosion of metal do not occur.
According to the third aspect of the present invention, even if the printing layer is not covered with the synthetic resin film, the printing layer is covered with the protective film, so that the printing layer is not damaged.
Further, according to the invention of claim 4 , adhesion of an aluminum material to a working tool in post-processing such as necking when using an aluminum can body is prevented, and this kind of continuous production becomes possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a metal can body according to a reference example of the present invention.
FIG. 2 is a cross-sectional view of the metal can body according to the first embodiment of the present invention.
FIG. 3 is a sectional view of a metal can body according to Embodiment 2 of the present invention.
FIG. 4 is a sectional view of a metal can body according to Embodiment 3 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Metal can body 12 Can body 14 Synthetic resin film 16 Printing layer 17 Adhesive layer 20 Protective coating

Claims (4)

A synthetic resin film having a printed layer and an adhesive layer formed on one surface, via the adhesive in a state where the upper end of the synthetic resin film is located at a position exposing the opening end of the can body. A metal can body, which is adhered to the can body, and at least a portion from an opening end of the can body to a portion of the synthetic resin film to be subjected to post-processing is covered with a protective coating. The metal can body according to claim 1, wherein the synthetic resin film is entirely covered with a protective coating, including an upper end, a lower end, and both ends in a circumferential direction. A synthetic resin film having a printed layer formed on one surface and an adhesive layer formed on the other surface, with the upper end of the synthetic resin film positioned at a position where the opening end of the can body is exposed. A metal can body, which is adhered to the can body, and is covered with a protective coating on all of the synthetic resin film, including the upper end, lower end, and both ends in the circumferential direction, and a printing layer. The metal can body according to any one of claims 1 to 3, wherein the metal can body is formed of aluminum .

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