JPH11171179A - Pull-top can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pull-top can capable of protecting contents contained in a can main body without deteriorating unsealability due to a pull-top mechanism mounted to a lid and without causing a hair-ring on the circumference of an unsealed part of the lid. SOLUTION: This pull-top can comprises a can main body 1 whose upper part is opened, and whose inner face is laminated with an organic resin film, and a lid made of aluminum, which is caulked and joined to the opening of the can main body 1 and has a pull-top mechanism. The lid is laminated with porous organic resin films 4 and 5 having many fine through-bores, or many fine unthrough-bores, on an outer face of the lid and on an inner face thereof with the aid of adhesive layers, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pull-top can, and more particularly to a pull-top can with an improved lid.

[0002]

2. Description of the Related Art Recently, as a can containing soft drinks, beer, and other seafood, a can having a structure having a lid having a pull-top mechanism that can be easily opened is known. A conventional pull-top can comprises a can body made of steel or aluminum with an open top, and a lid having a pull-top mechanism that is caulked to the opening of the can body. For example, in the case of a soft drink can, the pull-top mechanism is formed by joining an opening formed by a horseshoe-shaped groove formed on the lid by pressing to a pin on the outside of the lid so as to contact the surface thereof. And tabs. Such a pull-top mechanism is opened by raising the tab in the vertical direction with a finger to bend the lid portion located inside the horseshoe-shaped opening portion toward the can body. The lid is made of soft aluminum so that a cut can be easily formed along the horseshoe-shaped opening of the pull-top mechanism.

[0003] An organic resin film such as a polyethylene terephthalate film is laminated on the inner surface of the can body, and the quality of the film is degraded by direct contact of the contents with steel or aluminum as the material of the can body. Has been prevented.

On the other hand, when an organic resin film such as the polyethylene terephthalate film is laminated on the inner surface of the lid to which the pull-top mechanism is attached,
Since the organic resin film has a property of not easily tearing (breaking), formation of a cut in the lid by the pull-top mechanism is inhibited. As a result, it becomes substantially impossible to open the lid by the pull-top mechanism.

[0005] For this reason, the contents are the material of the lid without impairing the openability of the pull-top mechanism by baking and painting the inner surface of the lid with, for example, a submicron-order epoxyphenol-based resin thin film. Protection is provided without direct contact with the aluminum.

However, the baking coating of the epoxy phenolic resin thin film on the inner surface of the lid not only deteriorates the working environment but also requires a large amount of water for washing after the coating, thereby increasing running costs. Further, there is a problem that the resin thin film baked on the inner surface of the lid has a lower effect of protecting the contents than the organic resin film laminated on the inner surface of the can body.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a pull-top mechanism attached to a lid without impairing the opening property.
Another object of the present invention is to provide a pull-top can that can protect contents contained in a can main body without causing hairing around an opening portion of a lid.

[0008]

According to the present invention, there is provided a pull-top type can having an opening at an upper portion, an inner surface laminated with an organic resin film, and a caulking joint at an opening of the can body to form a pull-top mechanism. Having a lid made of aluminum having a porous organic resin film having a large number of fine through-holes or non-through-holes on the outer surface and the inner surface, each of which is laminated via an adhesive layer. It is characterized by the following.

[0009] Another pull-top type can according to the present invention has a can body having an open upper part and an inner surface laminated with an organic resin film, and is caulked and joined to the opening of the can body.
Aluminum lid having a pull-top mechanism, the lid is laminated with a porous organic resin film having a large number of fine through holes or non-through holes on the outer surface via an adhesive layer, and the inner surface The organic resin film is laminated via a fragile adhesive layer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a pull-top type can according to the present invention will be described in detail. This pull-top can includes a can body having an open top and an inner surface laminated with an organic resin film, and an aluminum lid having a pull-top mechanism, which is caulked to the opening of the can body.

For example, in the case of a can for soft drinks, the pull-top mechanism abuts an opening portion formed of a horseshoe-shaped groove formed on the lid by pressing, and a surface of the lid outside the lid. And a tab which is pin-joined as described above.

Further, the lid has first and second porous organic resin films each having a large number of fine through-holes on the outer surface and the inner surface, each of which is laminated via an adhesive layer. The can body is made of, for example, steel or aluminum.

The organic resin film laminated on the inner surface of the can body includes, for example, a polyester film,
Oriented polypropylene films and the like can be mentioned. The first and second porous organic resin films laminated on the outer surface and the inner surface of the lid are described in Japanese Patent Publication No. 6-61.
It is manufactured by the manufacturing apparatus of the porous film disclosed in JP-A-859. The manufacturing apparatus includes a supply unit for supplying a long film; a first rotatable roll having a large number of particles having a Mohs hardness of 5 or more (for example, diamond particles) having sharp corners adhered to a surface thereof; And a second roll rotatable in the opposite direction with respect to the first and second rolls are arranged to face each other so that the long film passes between them, A punching unit in which one of the rolls is fixed and the other is movably arranged in the direction opposite to the one of the rolls; provided in the vicinity of both ends of the movable roll of the unit; Pressure adjusting means for adjusting the pressing force on the film.

The first porous organic resin film laminated on the outer surface of the lid has an average opening diameter of 10 to 100 μm.
It is preferable to have a form in which through holes or non-through holes are opened at a density of 500 / cm ² or more in a polyester film such as a polyethylene terephthalate film or an organic resin film such as nylon or oriented polypropylene film. . The porous organic resin film having through holes or non-through holes having such an average opening diameter and density has a tear strength sufficiently lower than that of the first organic resin film in a non-porous state, and the organic resin in a non-porous state. Shows higher tearability (breakability) than films. For this reason,
When the lid is opened by the pull-top mechanism, it is possible to prevent hair ring, which is a residue of the organic resin film, from being formed around the opening. In particular, it is preferable to use a first porous organic resin film having a large number of through-holes from the viewpoint of preventing the occurrence of the hair ring.

The reason why the average opening diameter of the through holes or the non-through holes of the first porous organic resin film is specified is as follows. The average opening diameter is 10 μm
When it is less than the above, it becomes difficult not only to easily open the lid on which the first porous organic resin film is laminated on the outer surface by the pull-top mechanism, but also to cause hairing due to the residue of the organic resin film around the opening. May occur. On the other hand, if the average opening diameter exceeds 100 μm, moisture and the like easily penetrate, causing corrosion at the rib portion with the main body, and it may be difficult to effectively protect the lid. More preferably, the average opening diameter of the through holes or the non-through holes is 5 to 50 μm.

The density of through-holes or non-through-holes of the first porous organic resin film is defined for the following reasons. When the density is less than 500 pieces / cm ² , it becomes difficult to laminate the first porous organic resin film having high tearability on the outer surface of the lid.
The upper limit of the density is not particularly limited. However, through-holes or non-through-holes having a density of 25,000 / cm ² can be formed in a single treatment by the above-described porous film manufacturing apparatus. More preferably, the density of the through holes or the non-through holes is 1,000 holes / cm ² to 50 holes / cm ^2.
00 / cm ² .

The first porous organic resin film has a thickness of 10
It preferably has a thickness of ３０30 μm. When the thickness of the first porous organic resin film is less than 10 μm,
It becomes difficult to effectively protect the outer surface of the lid. On the other hand, if the thickness of the first porous organic resin film exceeds 30 μm, even if a large number of fine through holes or non-through holes are formed in the organic resin film of this thickness, the opening property by the above-described pull-top mechanism is not improved. May be damaged. More preferably, the thickness of the first porous organic resin film is 12 to 20 μm.
m.

When the first porous organic resin film having a large number of non-through holes is laminated on the outer surface of the lid via an adhesive layer, the openings of the plurality of non-through holes are formed on the outer surface of the lid. Or may be bonded such that the opening of the non-through hole is located on the side opposite to the outer surface of the lid. However, in the former case, a part of the adhesive layer interposed between the lid and the first porous organic resin film is embedded through the openings in the large number of non-through holes.

When the first porous organic resin film having a large number of through holes is laminated on the outer surface of the lid via an adhesive layer, the adhesive is embedded in a part of the through holes.

The first porous organic resin film in which a part of the adhesive layer is embedded in a through-hole or a part that is not penetrated exhibits sufficiently excellent tearing property as compared with a non-porous organic resin film. .

The second porous organic resin film laminated on the inner surface of the lid has an average opening diameter of 0.5 to 100 μm.
m having a density of not less than 500 / cm ² through holes in a polyester film such as a polyethylene terephthalate film or an organic resin film such as a nylon or oriented polypropylene film. preferable. The second porous organic resin film having through holes or non-through holes having such an average opening diameter and density has a tear strength sufficiently lower than that of an organic resin film in a non-porous state, and the organic resin in a non-porous state. Shows higher tearability (breakability) than films.

The reason why the average opening diameter of the through-holes or the non-through-holes of the second porous organic resin film is specified is as follows. The average opening diameter is 0.5μ
If it is less than m, it may be difficult to easily open the lid with the second porous organic resin film laminated on the inner surface by the pull-top mechanism. On the other hand, when the average opening diameter exceeds 100 μm, there is a possibility that the protection of the contents accommodated in the can cannot be sufficiently achieved. The more preferable average opening diameter of the through hole or the non-through hole is,
2 to 50 μm.

The density of through-holes or non-through-holes of the second porous organic resin film is defined for the following reasons. When the density is less than 500 pieces / cm ² , it becomes difficult to laminate the second porous organic resin film having high tearability on the inner surface of the lid.
The upper limit of the density is not particularly limited. However, through-holes or non-through-holes having a density of 25,000 / cm ² can be formed in a single treatment by the above-described porous film manufacturing apparatus. More preferably, the density of the through holes is from 1,000 / cm ^{2 to} 5,000 / cm ² .

The second porous organic resin film has a thickness of 10
It preferably has a thickness of 40 μm. When the thickness of the second porous organic resin film is less than 10 μm,
There is a risk that the protection of the contents contained in the can cannot be sufficiently achieved. On the other hand, when the thickness of the second porous organic resin film exceeds 40 μm, even if a large number of fine through holes or non-through holes are formed in the organic resin film of this thickness, the tearing property is reduced, and the above-described method is performed. The openability by the pull-top mechanism may be impaired. More preferably, the thickness of the second porous organic resin film is 12 to 25 μm.

As the adhesive, a general adhesive applied to foods can be used. The thickness of the adhesive layer is preferably 5 to 20 μm from the viewpoint of tearability and protection of contents.

The lid is manufactured, for example, by the following method. A porous organic resin film having a large number of fine through holes or non-through holes described above is laminated on both sides of an aluminum thin plate via an adhesive layer, and the aluminum thin plate is punched into a circular shape and pressed on one surface. After forming the opening part consisting of a horseshoe-shaped groove
Fabricated by pinning a tab to the other surface.

The above-described pull-top can according to the present invention has a can body having an opening at the top and an inner surface laminated with an organic resin film, and a caulking joint at the opening of the can body. And a lid made of aluminum. The lid is formed by laminating first and second porous organic resin films each having a large number of fine through holes or non-through holes on the outer surface and the inner surface via an adhesive layer.

In the pull-top can having such a structure, when the tab of the pull-top mechanism is vertically raised with a finger, the dove end near the pin joint is located on the inside of the horseshoe-shaped opening. Press the surface toward the can body. When the tab end is pressed, the first and second porous organic resin films laminated on the outer and inner surfaces of the lid have a large number of fine through-holes or non-opening holes acting as tearing starting points (rupture starting points). A through hole is opened.
For this reason, notches are formed along the horseshoe-shaped groove not only in the aluminum lid but also in each of the porous organic resin films, and the lid portion located inside the horseshoe-shaped opening portion is the cutout. It is folded toward the inside of the can body and opened.

In particular, by laminating the first porous organic resin film on the outer surface of the lid, the appearance of the opened portion of the lid can be improved. That is, it is possible to open the lid by attaching the above-described pull-top mechanism to a lid having an ultra-thin organic resin film laminated on the outer surface thereof, and raising the tab of the pull-top mechanism vertically with a finger. However, after such opening, the organic resin film is in a non-porous state,
Hair ring, which is a residue of the organic resin film, is formed around the lid, and appearance is significantly impaired. From such a fact, by laminating the first porous organic resin film having a large number of through holes or non-through holes formed on the outer surface of the lid, when the lid is opened by the pull-top mechanism described above, A through hole or a non-through hole acts as a tear initiation point. For this reason, it is possible to prevent hair ring, which is a residue of the organic resin film, from being generated around the opened portion of the lid, and to enhance the appearance of the opened portion of the lid.

Therefore, in the pull-top can according to the present invention, the porous organic resin film laminated on the outer surface and the inner surface of the lid does not impair the openability of the pull-top mechanism and generates hair that impairs the appearance. It can be easily opened without the need. Moreover,
Since the organic resin film is laminated on the inner surface of the can main body, and the second porous organic resin film is also laminated on the inner surface of the lid via an adhesive layer, the contents are the same as those of the can main body and the lid. Oxidation or the like caused by direct contact with a material such as aluminum can be prevented and quality can be maintained for a long period of time. At this time, when a through-hole is formed in the first porous organic resin film, a part of the through-hole is filled with the adhesive. Direct contact with a material such as aluminum of the lid can be prevented. Moreover, since the outer surface of the lid is laminated with the first porous organic resin film, the outer surface of the lid can be protected from the outside.

Further, in the pull-top type can according to the present invention, the second porous organic resin film laminated on the inner surface of the lid body is different from a conventional protective thin film formed by baking an epoxyphenol-based resin. Since the excellent content protection effect can be exhibited, the quality can be maintained for a long period of time. In addition, since the first and second porous organic resin films on the outer surface and inner surface of the lid can be coated by a laminating method, a cleaning process that requires an enormous amount of water after coating as in a conventional baking coating. Can be omitted, and the running cost can be greatly reduced.

Next, another pull-top can according to the present invention will be described in detail. This pull-top type can has an opening at the top, a can body having an inner surface laminated with an organic resin film, and an aluminum lid having a pull-top mechanism, for example, which is crimped to the opening of the can body. I do.

In the lid, a porous organic resin film having a large number of fine through holes or non-through holes on the outer surface is laminated via an adhesive layer, and the organic resin film is weak on the inner surface. Laminated through.

The can body is made of, for example, steel or aluminum. As the organic resin film to be laminated on the inner surface of the can main body, the same as the above-mentioned pull-top can is used.

The above-mentioned porous organic resin film is made of
No. 61859 discloses a porous film manufacturing apparatus. Like the first porous organic resin film of the pull-top can, the porous organic resin film has an average opening diameter of 10 to 100 μm, more preferably 5 to 50 μm, and has 500 through holes or non-through holes.
cm ² or more, more preferably 1000 / cm ² to 50
Perforated in a polyester film such as a polyethylene terephthalate film or an organic resin film such as a nylon or oriented polypropylene film with a density of 00 pieces / cm ² and a thickness of 10 to 30 μm, more preferably 12 to 20 μm. It preferably has a form. A porous organic resin film having a through hole or a non-through hole having such an average opening diameter and density has a tear strength sufficiently lower than that of a non-porous organic resin film, and a non-porous organic resin film. It shows higher tearability (breakability). Therefore, when the lid is opened by the pull-top mechanism, it is possible to prevent hair ring, which is a residue of the organic resin film, from being formed around the opening.

When the first porous organic resin film having a large number of non-through holes is laminated on the outer surface of the lid via an adhesive layer, the openings of the plurality of non-through holes are formed on the outer surface of the lid. Or may be bonded such that the opening of the non-through hole is located on the side opposite to the outer surface of the lid. However, in the former case, a part of the adhesive layer interposed between the lid and the first porous organic resin film is embedded through the openings in the large number of non-through holes.

When the first porous organic resin film having a large number of through holes is laminated on the outer surface of the lid via an adhesive layer, the adhesive is embedded in a part of the through holes.

The first porous organic resin film in which a part of the adhesive layer is embedded in a through-hole or a part that is not penetrated exhibits sufficiently superior tearing property as compared with a non-porous organic resin film. .

As the adhesive for laminating the porous organic resin film, a general adhesive applied to foods can be used. The thickness of the adhesive layer is preferably 5 to 20 μm from the viewpoint of tearability and protection of contents.

As the organic resin film laminated on the inner surface of the lid, for example, a polyester film such as a polyethylene terephthalate film, or a nylon or oriented polypropylene film can be used. This organic resin film preferably has a thickness of 3 to 6 μm. If the thickness of the organic resin film is less than 3 μm, there is a possibility that the protection of the contents contained in the can cannot be sufficiently achieved. On the other hand, if the thickness of the organic resin film exceeds 6 μm, the opening property by the above-mentioned pull-top mechanism may be impaired. More preferably, the thickness of the organic resin film is 4 to 5 μm.

As the fragile adhesive used for laminating the organic resin film on the inner surface of the lid, for example, a heat-sealing adhesive based on low-molecular-weight polyester is preferable. This layer of adhesive is 10-13
It preferably has a thickness of μm. The adhesive layer made of such an adhesive has a brittle property, so that when the lid is opened by the above-described pull-top mechanism, the lid follows the pushing of the lid toward the can body side. The bonded organic resin film can be easily torn.

The lid is manufactured, for example, by the following method. First, the organic resin film is laminated on one side of a thin aluminum plate via an adhesive layer. Subsequently, an organic resin film is laminated on the surface on the opposite side of the aluminum thin plate via a heat-sealing adhesive, and the organic resin film is laminated through a fragile adhesive layer by heat treatment. Thereafter, the aluminum thin plate is punched into a circular shape and pressed to form an opening portion or the like formed of a horseshoe-shaped groove in the thin plate on the organic resin film side. The lid is manufactured by pin-joining a tab to the side).

Another pull-top can according to the present invention described above has a can body having an opening at the top and an inner surface laminated with an organic resin film, and a caulking joint at the opening of the can body. An aluminum lid having a pull-top mechanism. The lid is formed by laminating a porous organic resin film having a large number of fine through holes or non-through holes on an outer surface thereof through an adhesive layer, and laminating an organic resin film on the inner surface thereof through a fragile adhesive layer. Have been.

In the pull-top can having such a structure, when the tab of the pull-top mechanism is vertically raised with a finger, the dove end near the pin joint is located on the inside of the horseshoe-shaped opening. Press the surface toward the can body. At the time of pressing the tab end, the porous organic resin film laminated on the outer surface of the lid is provided with a large number of fine through-holes or non-through-holes acting as tearing starting points (rupture starting points), and Since the organic resin film on the inner surface is laminated via the fragile adhesive layer, not only the aluminum lid but also the porous organic resin film and the organic resin film on the outer inner surface are formed in the horseshoe-shaped groove. A notch is formed along the lid, and the lid portion located inside the horseshoe-shaped opening is bent toward the inside of the can body and opened.

In particular, by laminating a porous organic resin film on the outer surface of the lid, it is possible to prevent hair ring, which is a residue of the organic resin film, from being generated around the opened portion of the lid similarly to the above-mentioned pull-top can. The appearance of the opening portion of the lid can be improved.

Therefore, another pull-top type can according to the present invention is such that the pull-top mechanism is opened by a porous organic resin film laminated on the outer surface of the lid and an organic resin film laminated on the inner surface via a fragile adhesive layer. It can be easily opened without impairing the properties and without causing hairing that impairs the appearance.
In addition, since the organic resin film is laminated on the inner surface of the can body, and the organic resin film is also laminated on the inner surface of the lid via an adhesive layer, the contents are aluminum of the can body and the lid. Oxidation or the like caused by direct contact with such a material can be prevented and quality can be maintained for a long period of time. Moreover, since the outer surface of the lid is laminated with a porous organic resin film, the outer surface of the lid can be protected from the outside.

Further, in the pull-top type can according to the present invention, the organic resin film laminated on the inner surface of the lid is more excellent in content than a conventional protective thin film formed by baking an epoxy phenol resin. , The quality can be maintained for a long period of time. In addition, since the porous organic resin film and the organic resin film on the outer surface and the inner surface of the lid can be coated by a laminating method, a washing step that requires an enormous amount of water after coating as in the conventional baking coating is omitted. As a result, running costs can be significantly reduced.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a top view of a pull-top can for soft drinks of Embodiment 1, FIG. 2 is a front view of the pull-top can of FIG. 1, and FIG. 3 is a lid used for the pull-top can of FIG. FIG. 4 is a plan view showing a body surface, FIG. 4 is a cross-sectional view of the shoulder of the pull-top can of FIG. 2, and FIG. 5 is an enlarged cross-sectional view of the lid of FIG.

The can body 1 made of, for example, stainless steel having an open upper portion is laminated on its inner surface with a polyethylene terephthalate film 2 which is an organic resin film. For example, an aluminum lid 3 having a thickness of 300 μm
Is caulked to the opening of the can body 1. The first and second porous polyethylene terephthalate films (porous PET films) 4, 5 are provided on the outer surface and the inner surface of the lid 3, for example, as shown in FIGS.
10 μm thick made of liquid polyester polyurethane
Are laminated via the adhesive layers 6 and 7. As shown in FIG. 5, the first porous PET film 4 has a through-hole 9 having an opening diameter of 70 to 80 μm in a polyethylene terephthalate film 8 having a thickness of 12 μm, for example.
It has a structure in which a number of holes are uniformly formed at a density of 0 / cm ² . In addition, the adhesive of the adhesive layer 6 is embedded in the large number of through holes 9 of the first porous PET film 4 by penetrating through the openings of the through holes 9. As shown in FIG. 5, the second porous PET film 5 is, for example, a polyethylene terephthalate film 1 having a thickness of 12 μm.
The number of through-holes 11 having an opening diameter of 70 to 80 μm is 50
It has a structure in which a number of holes are uniformly formed at a density of 00 / cm ² . Further, the adhesive of the adhesive layer 7 penetrates through the openings of the through holes 11 and is embedded in the many through holes 11 of the second porous PET film 5.

The pull-top mechanism 12 is formed on the lid 3. As shown in FIGS. 1 and 3, the pull-top mechanism 12 is formed by pressing a shoe-shaped recess 13 formed on the outer surface of the lid 3 by pressing, and a curved surface area of the recess 13 by pressing. An unsealing portion 14 formed of a horseshoe-shaped groove in which a cut is formed at the time of unsealing, and a pin 15 positioned near the center of the unsealing portion 13 opposite to the unsealing portion 14 and joined to the surface of the unsealing portion 13. And an elongated tab 16 having two abutting holes.

The opening of the pull-top can having such a structure will be described with reference to FIGS. Holding the can body 1 with one hand and vertically raising the tab 16 of the pull-top mechanism 12 with the fingers of the other hand, the end of the dove 16 near the joint of the pin 15 as shown in FIG. The surface of the lid 3 located inside the horseshoe-shaped opening 14 is
Press toward the side. When the end of the tab 16 is pressed, a large number of through holes 9, 1, 1
The first and second porous PET films 4 and 5 which are easy to tear and have 1 are laminated. Therefore, not only the lid 3 but also the first and second porous PET films 4 and 5 are cut along the grooves of the horseshoe-shaped opening portion 14 as shown in FIGS. 6 and 7. At the same time, the lid 3 inside the horseshoe-shaped opening 14 is made of PET around the opening 14.
Without producing hair ring which is a residue of film,
It is bent toward the inside of the can body 1 and opened.

That is, when the lid 3 inside the horseshoe-shaped opening 14 is pressed by the end of the tab 15, the first and second porous PET films laminated on the outer and inner surfaces of the lid 3 are formed. 4 and 5 have a large number of fine through holes 9,
11 is opened, and these through holes 9 and 11 function as tearing starting points (rupture starting points). For this reason, in the initial stage of the pressing, a cut is formed along the groove of the unsealing portion 14 located around the pressing portion as shown in FIGS. Cuts are also formed in the PET films 4 and 5 along the large number of through holes 9 and 11. Further, when the tab 15 is raised vertically, the pressing stroke on the lid 3 located inside the horseshoe-shaped opening 14 becomes longer. For this reason,
The groove of the opening portion 14 is cut long together with the first and second porous PET films 4 and 5 so that the lid 3 inside the horseshoe-shaped opening portion 14 faces the inside of the can body 1. It is folded and opened.

When a lid having a non-porous PET film laminated on the outer and inner surfaces is used, the tab is raised vertically and the end of the tab is attached to the lid inside the horseshoe-shaped opening. Even if pressed in the direction, the tearing force (breaking force) of the non-porous PET film is sufficiently large as compared with the pressing force, so that the PET film is not broken by the pressing force. For this reason, when the non-porous PET film is laminated even when the horseshoe-shaped opening portion is formed on the lid, a cut is prevented from being formed in the groove of the opening portion located around the pressing portion. . As a result, opening by the pull-top mechanism becomes difficult.

Therefore, the pull-top can of the first embodiment functions as a protective film for the outer and inner surfaces of the lid 3.
Since the ET film is porous having a large number of through-holes 9 and 11, it can be easily opened without obstructing the opening property of the pull-top mechanism 12 as in the case of using a non-porous PET film. Can be. Moreover, by laminating the first porous PET film 4 having a large number of through holes 9 on the outer surface of the lid 3, hairing around the opening portion 14 of the lid 3 in the initial stage of the opening is prevented. Can be prevented, and its appearance can be enhanced.

The can body 1 has a PET film 2 laminated on the inner surface thereof. A second porous PET film 5 having a large number of fine through holes 11 is also laminated on the inner surface of the lid 3 via an adhesive layer 7, and the inside of the through holes 11 is filled with an adhesive. It has good barrier properties. For this reason, the contents in the can body 1 are prevented from being oxidized or the like due to direct contact with stainless steel as a material of the can body 1 and aluminum as a material of the lid 3. As a result, even when the soft drink pull-top can is stored for a long period of time, it is possible to maintain the quality at the time of injecting the contents into the can main body 1.

Further, the protective film on the inner surface of the lid 3 is made of a porous PET film 4 laminated through an adhesive layer 5.
Therefore, the quality of the contents can be maintained for a long period of time as compared with a conventional protective thin film formed by baking of an epoxy phenol resin. In addition, the first and second porous organic resin films 4 on the outer and inner surfaces of the lid 3
5 can be coated by a laminating method, so that a washing step requiring an enormous amount of water after coating as in the conventional baking coating can be omitted, and the running cost can be greatly reduced.

The first and second porous PET laminated on the outer and inner surfaces of the lid 3 in the first embodiment.
As the film, a film in which the through holes 9 and 11 were formed was used, but the film is not limited to this. For example, as shown in FIG. 10, a first porous PET film 4 having a large number of through holes 9 in a PET film 8
And the inner surface of the lid 3 is PET
A second porous PET film 19 having a large number of non-through holes 18 in the film 17 may be laminated via the adhesive layer 7 such that the opening of the non-through hole 18 is located on the inner side. Further, as shown in FIG. 11, a first porous PET film 4 having a large number of through holes 9 in a PET film 8 is laminated on the outer surface of the lid 3 via an adhesive layer 6,
The second porous PET film 19 having a large number of non-through holes 18 in the PET film 17 on the inner surface of the lid 3 is bonded to the adhesive layer so that the opening of the non-through hole 18 is located on the opposite side to the inner surface. 7 may be laminated. Further, as shown in FIG. 12, a first porous PET film 22 having a large number of non-through holes 21 in a PET film 20 on the outer surface of the lid 3 is positioned such that the opening of the non-through hole 21 is on the opposite side to the outer surface. And a second porous PET film 19 having many non-through holes 18 in a PET film 17 on the inner surface of the lid 3.
May be laminated via the adhesive layer 7 so that the opening of the non-through hole 18 is located on the side opposite to the inner surface.

The pull-top can incorporating the lid having the structure shown in FIGS. 10 to 12 has the same excellent function as that of the first embodiment. (Example 2) Fig. 13 is a top view of a pull-top can for soft drinks of Example 2, Fig. 14 is a front view of the pull-top can of Fig. 13, and Fig. 15 is a shoulder of the pull-top can of Fig. 13. FIG. 16 is an enlarged sectional view of the lid shown in FIG. The same members as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The pull-top can according to the second embodiment includes a can body 1 made of stainless steel having an open top,
And an aluminum lid 3 having a thickness of, for example, 300 μm, which is crimped to the opening. The polyethylene terephthalate film 2 is laminated on the inner surface of the can body 1.

As shown in FIGS. 15 and 16, a porous polyethylene terephthalate film (porous PET film) 23 is provided on the outer surface of the lid 3 with an adhesive layer 24 made of, for example, a two-component polyester polyurethane having a thickness of 10 μm.
Laminated through. As shown in FIG. 16, the porous PET film 14 is, for example, 70-80 μm thick on a polyethylene terephthalate film 25 having a thickness of 12 μm.
through-hole 13 having the aperture diameter of μm is 5000 / cm ²
It has a structure in which many holes are uniformly opened at a density of. Also, a large number of through holes 26 of the porous PET film 23 are formed.
Inside the adhesive of the adhesive layer 24, the through holes 26 are formed.
It is embedded and penetrates through the opening.

The PET film 27 having a thickness of 6 μm is laminated on the inner surface of the lid 3 through a heat-sealing adhesive layer 28 based on a low-molecular-weight polyester having a thickness of 10 μm. That is, the PET film 27 is laminated on the inner surface of the lid 3 via the fragile adhesive layer 28.

The pull-top mechanism 12 is formed on the lid 3 as shown in FIG. The opening of the pull-top can having such a configuration will be described with reference to FIGS.

When holding the can body 1 with one hand and vertically raising the tab 16 of the pull-top mechanism 12 with the finger of the other hand, as shown in FIG. The end portion presses the surface of the lid 3 located inside the horseshoe-shaped opening portion 14 toward the can body 1. When the end of the tab 16 is pressed, the outer surface of the lid 3 has a large number of through-holes 26 and is easy to tear.
An ET film 23 is laminated, and a PET film 27 is laminated on the inner surface thereof via a brittle adhesive layer 28. Therefore, not only the lid 3 but also the porous PET film 23 on the outside and the P
The ET film 27 is also formed with a cut along the groove of the horseshoe-shaped opening portion 14 so that the lid 3 inside the horseshoe-shaped opening portion 14 faces the inside of the can body 1 as shown in FIG. It is folded and opened.

That is, when the end of the tab 15 presses the lid 3 inside the horseshoe-shaped opening 14, the porous PET film 23 laminated on the outer surface of the lid 3 is pressed.
A large number of fine through-holes 26 are opened in the, and these through-holes 26 act as tearing starting points (rupture starting points). Also,
The inner surface of the lid 3 is made of PET via a fragile adhesive layer 28.
A film 27 is laminated and the fragile adhesive layer 2
8 acts as a fracture starting point. For this reason, in the initial stage of the pressing, as shown in FIGS. 18 and 19, a cut is formed along the groove of the unsealing portion 14 located around the pressing portion, and the porous PET film 23 laminated at the same time also has the same shape. Cuts are formed along the plurality of through holes 26, and cuts are formed along the opening portion 14 in the PET film 27 laminated by the fragile adhesive layer 28. Further, when the tab 11 is raised vertically, the pressing stroke on the lid 3 located inside the horseshoe-shaped opening 14 becomes longer. For this reason, the groove of the opening part 14 is formed by the porous PET film 2.
3 and long cut with PET film 27,
The lid 3 inside the horseshoe-shaped opening portion 14 is bent toward the inside of the can body 1 and opened.

Therefore, in the pull-top can of the second embodiment, a large number of through holes 26 are opened in the PET film 25 functioning as a protective film on the outer surface of the lid 3, and the fragile adhesive layer 28 is formed on the inner surface of the lid 3. Since the PET film 27 is laminated through the pull-up mechanism 12, the PET film 27 can be easily opened by the pull-top mechanism 12. Moreover, the porous PET film 2 having a large number of through holes 26 on the outer surface of the lid 3
By laminating 3, it is possible to prevent hairing from occurring around the unsealing portion 14 of the lid 3 at the initial stage of the unsealing, and to enhance the appearance thereof.

The can body 1 has a PET film 2 laminated on its inner surface. A PET film 27 is also laminated on the inner surface of the lid 3 via an adhesive layer 24. Therefore, the contents in the can body 1 are made of stainless steel, which is a material of the can body 1, and the lid 3.
Oxidation or the like due to direct contact with aluminum, which is a material of the above, is prevented. As a result, even when the pull-top can for soft drinks is stored for a long period of time, it is possible to maintain the quality at the time of injecting the contents into the can body.

Further, since the protective film on the inner surface of the lid 3 is made of the PET film 27 laminated via the adhesive layer 28, the content is smaller than that of the conventional protective thin film formed by baking with an epoxy phenol resin. The quality of goods can be maintained for a long time. In addition, since the porous organic resin film 23 and the PET film 27 on the outer surface and the inner surface of the lid 3 can be coated by a laminating method, a cleaning process that requires an enormous amount of water after coating as in a conventional baking coating. Can be omitted, and the running cost can be greatly reduced.

In the second embodiment, the through-hole 2 was formed as a porous PET film laminated on the outer surface of the lid 3.
Although the one in which 6 was opened was used, it is not limited to this.
For example, as shown in FIG. 20, a porous PET film 31 having a large number of non-through holes 30 in a PET film 29 on the outer surface of the lid 3 is bonded to the outside so that the opening of the non-through hole 30 is located on the outer surface side. Lamination may be performed via the layer 32. The pull-top can incorporating the lid having the structure shown in FIG. 20 has the same excellent function as that of the second embodiment.

In the first and second embodiments, the pull-top can for soft drinks has been described. However, the pull-top can for storing fish and shellfish whose whole lid is opened from the periphery of the opening of the can body can be similarly used. Can be applied.

[0070]

As described above in detail, according to the present invention, the pull-top mechanism attached to the lid body does not impair the opening property, and hairing does not occur around the opening portion of the lid body. Not only the can body but also the material of the lid can be protected, and the outer surface of the lid can be protected from the outside.
In addition, it is possible to provide a pull-top can that can maintain the quality of contents such as fish and shellfish over a long period of time and can reduce running costs.

[Brief description of the drawings]

FIG. 1 is a top view of a pull-top can for soft drinks according to a first embodiment of the present invention.

FIG. 2 is a front view of the pull-top can of FIG.

FIG. 3 is a plan view showing an inner surface of a lid used in the pull-top can of FIG. 1;

FIG. 4 is a sectional view of a shoulder of the pull-top can of FIG. 2;

FIG. 5 is an enlarged sectional view of the lid of FIG. 4;

FIG. 6 is a perspective view showing a state where the pull-top can of FIG. 1 is opened.

FIG. 7 is a perspective view showing the inner surface of the lid of the opened pull-top can of FIG. 6;

8 is a perspective view showing the inner surface of the lid of the pull-top can at the initial stage of opening in the pull-top can of FIG. 1;

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 7;

FIG. 10 is an enlarged sectional view of a lid of a pull-top can showing a modification of the first embodiment.

FIG. 11 is an enlarged sectional view of a lid of a pull-top can showing another modification of the first embodiment.

FIG. 12 is an enlarged cross-sectional view of a lid of a pull-top can showing still another modification of the first embodiment.

FIG. 13 is a top view of a pull-top can for soft drinks in Embodiment 2 of the present invention.

FIG. 14 is a front view of the pull-top can of FIG.

FIG. 15 is a sectional view of a shoulder portion of the pull-top can of FIG.

FIG. 16 is an enlarged sectional view of the lid shown in FIG. 13;

FIG. 17 is a perspective view showing a state where the pull-top can of FIG. 13 is opened.

FIG. 18 is a perspective view showing the inner surface side of the lid at the initial stage of opening the pull-top can of FIG. 13;

19 is a sectional view taken along the line XIX-XIX in FIG.

FIG. 20 is an enlarged sectional view of a lid of a pull-top can showing a modification of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Can body, 2 ... Polyethylene terephthalate film, 3 ... Lid, 4, 5, 19, 22, 23, 31 ... Porous polyethylene terephthalate film, 6, 7, 24, 28, 32 ... adhesive layer, 9, 11, 26 ... through-hole, 12 ... pull-top mechanism, 14 ... opening part, 16 ... tab, 18, 21, 30 ... non-through hole.

Claims (5)

[Claims] 1. A can body having an upper part opened and an inner surface laminated with an organic resin film, and an aluminum lid body having a pull-top mechanism, which is caulked and joined to the opening part of the can body. A pull-top can, wherein the body is laminated with a porous organic resin film having a large number of fine through holes or non-through holes on the outer surface and the inner surface via an adhesive layer. 2. The porous organic resin film laminated on the outer surface of the lid has an average opening diameter of 10 to 100 μm.
The pull-top can according to claim 1, characterized in that it is a polyethylene terephthalate film having a thickness of 10 to 30 µm, wherein m fine through-holes are opened at a density of 500 / cm ² or more. 3. The porous organic resin film laminated on the inner surface of the lid has an average opening diameter of 0.5 to 100 μm.
^2. The pull-top can according to claim 1, wherein the fine through-hole is a polyethylene terephthalate film having a thickness of 10 to 40 [mu] m and having a density of 500 / cm < ² > or more. 4. A lid body comprising: a can body having an upper part opened and an inner surface laminated with an organic resin film; and an aluminum lid body having a pull-top mechanism, which is crimped and joined to the opening part of the can body. In the body, a porous organic resin film having a large number of fine through holes or non-through holes on the outer surface is laminated via an adhesive layer, and the organic resin film is laminated on the inner surface via a fragile adhesive layer. A pull-top can characterized by the following: 5. The porous organic resin film laminated on the outer surface of the lid has an average opening diameter of 10 to 100 μm.
500 fine through holes or 500 / cm ²
5. The pull-top can according to claim 4, wherein the can is a polyethylene terephthalate film having a thickness of 10 to 30 [mu] m which is opened at the above density.