JP7835115B2 - packaging - Google Patents

Description

This invention relates to packaging.

A packaging structure is known in which a lid material is sealed around the periphery of the container's opening to close it, and the opening can be repeatedly opened and closed by repeatedly adhering and peeling off the lid material. This type of packaging is widely used, for example, to contain contents such as wet wipes (see Patent Document 1).

The lid material constituting the packaging is constructed by laminating a base sheet, an adhesive layer, and a sealant layer in that order. The layers are laminated in such a way that repeated peeling and re-adhesion are possible between the adhesive and sealant layers. The lid material seals the periphery of the container opening to close it. The lid material also has a tab protruding outwards.

In the packaging, when the tab is grasped and pulled upwards, first, at the seal area around the opening, the sealant layer and the container are firmly sealed. Therefore, the adhesive layer and the sealant layer separate, and the lid separates from the container, exposing the adhesive layer. Next, at the opening, the sealant layer and the container are not sealed. The sealant layer remains adhered to the adhesive layer while separating from the container, resulting in the packaging opening. Then, the lid, separated from the container, has its adhesive layer exposed at the seal area around the opening. By re-adhering it to the remaining sealant layer on the container, the opening can be closed again. This opening and closing process can be repeated multiple times.

Japanese Patent Publication No. 2020-189642

However, the packaging described in Patent Document 1 can be repeatedly opened and closed, and therefore lacks the function (tamper-evident function) to distinguish between a used, opened package and an unopened, unopened package. For this reason, when this packaging was sold commercially, it was further sealed in an outer bag to guarantee that the package was unopened.

This invention has been made in consideration of these circumstances, and aims to provide a packaging body that has a tamper-evident function, comprising a container having an opening and a lid material sealed around the periphery of the opening to close it, and capable of being opened and closed repeatedly.

To solve the above problems, this invention proposes the following means.
A packaging body according to a first aspect of the present invention comprises a container having an opening, a base sheet sealed around the periphery of the opening to close the opening and having heat-sealability, an adhesive layer, and a sealant layer, and a lid material formed by laminating the base sheet, the adhesive layer, and the sealant layer in this order, wherein the lid material has a tab protruding outward from a seal line formed on the periphery of the opening, the adhesive layer and the sealant layer are repeatedly peeled off and re-adhered to each other, and at least a portion of the tab is provided with a tab welded portion in which the base sheet and the sealant layer are welded together without the adhesive layer.

According to a second aspect of the present invention, the packaging according to the first aspect is characterized in that the sealant layer and the container are welded together at the tab welding portion.

According to a third aspect of the present invention, the packaging according to the first or second aspect is characterized in that, at the periphery of the opening, at least a portion of the area opposite to the tab provided on one side of the lid material, straddling the center of the lid material, is provided with an end-side welded portion in which the base sheet and the sealant layer are welded together without the adhesive layer.

According to a fourth aspect of the present invention, the packaging according to the first or second aspect is characterized in that the opening is formed in the container that spans two surfaces.

According to a fifth aspect of the present invention, the packaging according to the first or second aspect is characterized in that the opening has a flange provided around its periphery, and the lid material is sealed to the flange.

According to a sixth aspect of the present invention, the packaging according to the first or second aspect is characterized in that the opening has a flange formed by wrapping a sheet constituting the body around the outside of the opening, and the lid material is sealed to the flange.

According to the seventh aspect of the present invention, the packaging according to the first or second aspect is characterized in that the adhesive layer is thermoplastic, and the lid material is formed by extrusion lamination, in which the adhesive layer is pressed onto the base sheet and the sealant layer.

According to the present invention, a tab-welded portion is provided in a part of the tab at the end of the lid material, where the base sheet and sealant layer of the lid material are welded together. Therefore, when the lid material is peeled away from the container and opened, the base sheet and sealant layer, or the sealant layer and the container, must be separated at this tab-welded portion. Furthermore, the separated portion cannot be restored, and a trace of the separation remains, making it possible to distinguish between a used, opened package and an unopened, unopened package.

(a) is an explanatory perspective view of a packaging body according to the first embodiment of the present invention, and (b) is an explanatory cross-sectional view of the main part of the same packaging body. (a) is a perspective view illustrating the packaging when opened, and Figure 2(b) is a cross-sectional view of the main part of the packaging when opened. This is a perspective view illustrating a packaging body according to a second embodiment of the present invention. This is a perspective view illustrating a packaging body according to a third embodiment of the present invention. This is a perspective view illustrating a packaging body according to a fourth embodiment of the present invention. This is a perspective view illustrating a packaging body according to a fifth embodiment of the present invention. This is a cross-sectional view of the main part of the packaging used for explanation. This is a cross-sectional view of the main part of the packaging used for explanation when it is opened.

(First embodiment)
A first embodiment of the present invention will be described with reference to Figures 1 and 2.
Figure 1(a) is an explanatory perspective view of a packaging A according to the first embodiment of the present invention, and Figure 1(b) is an explanatory cross-sectional view of the main part of the packaging A. Figure 2(a) is an explanatory perspective view of the packaging A when it is open, and Figure 2(b) is an explanatory cross-sectional view of the main part of the packaging A when it is open.

As shown in Figure 1 or Figure 2, the packaging A according to the first embodiment of the present invention comprises a container 20 and a lid material 10.

The packaging A according to the first embodiment is an example in which a pillow bag is used as the container 20 having an opening 21.

The packaging material constituting this pillow bag has heat-sealable resin layers on both its front and back surfaces. The pillow bag may consist of a single layer of heat-sealable resin, or it may have a base layer interposed between the layers. Examples of heat-sealable resins include polyolefin resins such as low-density polyethylene resin, linear low-density polyethylene resin, medium-density polyethylene resin, and polypropylene resin. The packaging material base is a multilayer structure, for example, containing polyester resin, polyamide resin, ethylene-vinyl alcohol resin, polyvinyl chloride resin, polycarbonate resin, polyacrylonitrile resin, or acrylic resin. Furthermore, the packaging material base may contain metal foil, metal vapor-deposited film, or a vapor-deposited film with an inorganic oxide film within its layer structure. Each layer may be bonded and laminated by heat melting or by adhesive bonding.

The container 20 is provided with an opening 21 for dispensing the contents. In this example, the opening 21 is formed in a rectangular shape on the side without a back seal line. Examples of contents include tissue paper. Alternatively, the contents may be confectionery such as gummies or chocolates. Note that the contents are not shown in Figures 1 and 2.

Next, the lid material 10 is constructed by laminating a base sheet 11, an adhesive layer 12, and a sealant layer 13 in that order. The adhesive layer 12 and the sealant layer 13 are laminated in such a way that repeated peeling and re-adhesion can occur between them. The adhesive layer 12 is thin. Therefore, when strong heat and pressure are applied to the lid material 10, the adhesive layer 12 in the area where heat and pressure are applied moves to the surrounding area. As a result, the base sheet 11 and the sealant layer 13 come into direct contact and are welded together.

The base sheet 11 is formed from any resin layer. The base sheet 11 may have a single-layer structure or a multi-layer structure. Furthermore, the base sheet 11 may have layers of materials other than resin, such as metal or resin, interposed between the multiple resin layers. Examples of resins constituting the base sheet 11 include polyolefin resin, polyester resin, polyamide resin, ethylene-vinyl alcohol resin, polyvinyl chloride resin, polycarbonate resin, polyacrylonitrile resin, and acrylic resin. Examples of layers of materials other than resin include metal foil such as aluminum foil, metal vapor-deposited films, and inorganic vapor-deposited film paper such as inorganic oxides.

The adhesive layer 12 can be formed by applying a known adhesive. For example, the adhesive layer 12 may use an acrylic, butyl rubber, natural rubber, silicone, or polyisobutyl adhesive alone. Furthermore, the adhesive layer 12 may also contain appropriate additives such as agglomerating components like alkyl methacrylate, vinyl ester, acrylonitrile, styrene, and vinyl monomer; modifying components represented by unsaturated carboxylic acids, hydroxyl group-containing monomers, and acrylonitrile; or polymerization initiators, plasticizers, curing agents, curing accelerators, and antioxidants.

Furthermore, the sealant layer 13 can be made from polyolefin resins, as exemplified as heat-sealable resins constituting the container 20. Specifically, the sealant layer 13 can be low-density polyethylene resin, linear low-density polyethylene resin, medium-density polyethylene resin, polypropylene resin, etc.

In the present invention, a composite material constructed by laminating an adhesive layer 12 and a sealant layer 13 in that order can also be used as a resealable sealant (resealable sealant). For example, "Diamilon® MF RE," which is commercially available from Mitsubishi Chemical Corporation, can be used.
The lid material 10 may also have a printed layer formed on the adhesive layer 12 side of the base sheet 11, or other films or the like may be laminated on it.

In this embodiment, the lid material 10 is sealed to the periphery (edge) 22 of the container opening so as to close the opening 21. However, the lid material 10 can be divided into several regions depending on its positional relationship with the container 20 in the state sealed by the lid material 10.

First, there is the tab 10a that protrudes outward from the seal line formed on the periphery 22 of the container opening. The tab 10a is provided on the lid material 10. The tab 10a serves as a gripping piece when peeling the lid material 10 from the container 20 to open it, and is positioned to protrude outward from the seal line formed on one side of the periphery 22 of the container opening, which is the starting point for peeling. In the area of this tab 10a, strong heat pressure is applied to the lid material 10 in at least a part of it. As a result, the adhesive layer 12 between the base sheet 11 and the sealant layer 13 moves around this area. Then, the base sheet 11 and the sealant layer 13 come into direct contact and weld together without the adhesive layer 12 in between. When the area where the base sheet 11 and the sealant layer 13 are welded together is called the "tab welded portion 10x," not only are the base sheet 11 and the sealant layer 13 welded together, but the sealant layer 13 is also sealed to the container 20. Therefore, the base sheet 11, the sealant layer 13, and the container 20 are welded together as a single unit. For the lid material 10 to be detached from the container 20 and open, the tab welded portion 10x, where the base sheet 11, the sealant layer 13, and the container 20 are welded together as a single unit, must be broken. Furthermore, the broken portion cannot be restored, and a trace of the break remains.

Next, adjacent to the tab 10a is the peripheral seal region 10b, where the lid material 10 is sealed to the periphery 22 of the container opening. Following this is the opening-corresponding region 10c, which covers and closes the container opening 21. The periphery 22 of the container opening is provided in a closed curve shape surrounding the opening-corresponding region 10c. Therefore, as the lid material 10 peels off, the peeling continues past the opening-corresponding region 10c and again reaches the peripheral seal region 10b. The peripheral seal region 10b is located on the opposite side of the tab 10a, which is provided on one side of the lid material 10 with the center of the lid material 10 in between, on the periphery 22 of the container opening. For the sake of explanation, the peripheral seal region 10b following the opening-corresponding region 10c will be described in this way, divided into two parts.

First, in the peripheral sealing region 10b following the opening-corresponding region 10c, there is a portion where the base sheet 11 and the sealant layer 13 are in direct contact and welded together without the adhesive layer 12. This portion is referred to as the "end-side welded portion 10y." Similar to the tab welded portion 10x, this end-side welded portion 10y is a region where strong heat and pressure are applied to the lid material 10. Therefore, in the end-side welded portion 10y, the base sheet 11, the sealant layer 13, and the container 20 are integrally welded together. Because the end-side welded portion 10y, like the tab welded portion 10x, is a region where the base sheet 11, the sealant layer 13, and the container 20 are integrally welded together, the lid material 10 can be broken and peeled off if pulled with strong force. The broken portion cannot be restored, and a trace of the break remains.

The peripheral seal region 10b following the opening-corresponding region 10c can be divided into two regions based on the end-side welded portion 10y: the opening-side peripheral seal region 10b ₁ located on the opening-corresponding region 10c side, and the end-side peripheral seal region 10b ₂ located on the opposite side. When the lid material 10 is peeled off to open the container, the opening-side peripheral seal region 10b ₁ is the region where the lid material 10 is peeled off. In contrast, the end-side peripheral seal region 10b ₂ is the region where the lid material 10 is not peeled off and remains connected to the container 20.

Next, this packaging A can be opened as follows. As shown in Figure 2, when the lid material 10 is grasped by the tab 10a and pulled upward, it separates from the adhesive layer 12 and the sealant layer 13 in the area of the tab 10a. However, even within the area of the tab 10a, the adhesive layer 12 is not present in the tab welded portion 10x. Therefore, the lid material 10 separates from the container 20 by breaking either the weld between the base sheet 11 and the sealant layer 13, or the weld between the sealant layer 13 and the container 20. The force required to break the weld between the base sheet 11 and the sealant layer 13, or the force required to break the weld between the sealant layer 13 and the container 20, is greater than the force required to separate it from the adhesive layer 12 and the sealant layer 13. Furthermore, as mentioned above, if the welding between the base sheet 11 and the sealant layer 13, or between the sealant layer 13 and the container 20, is broken, it cannot be restored, and traces will remain. Whether the welding between the base sheet 11 and the sealant layer 13, or between the sealant layer 13 and the container 20, breaks depends on the relative strengths of the two welds. While either can break, Figure 2(b) illustrates an example where the lid material 10 is pulled upward with a force greater than the force required to break the welding between the base sheet 11 and the sealant layer 13, resulting in the welding breaking and the base sheet 11 separating from the sealant layer 13.

Then, when the lid material 10 is pulled upward with a force greater than the force required to separate it from the adhesive layer 12 and the sealant layer 13, the separation of the lid material 10 from the container 20 progresses. In the peripheral seal region 10b, the lid material 10 separates from the adhesive layer 12 and the sealant layer 13, as shown in Figure 2(b). The sealant layer 13 remains on the container 20 side, and the adhesive layer 12 is separated together with the base sheet 11. In Figure 2(b), the reference numeral "13 ₂ " indicates the sealant layer 13 remaining on the container 20 side, and the reference numeral "12 ₂ " indicates the adhesive layer 12 separated together with the base sheet 11. Since the adhesive layer 12 ₂ is exposed on the surface of the separated lid material 10 that faces the container 20 (the container side surface), it is possible to reseal the lid material 10 by re-adhering the adhesive layer 12 ₂ to the sealant layer 13 ₂ .

Next, the separation of the lid material 10 from the container 20 progresses to the opening area 10c. Since the opening area 10c is not sealed to the container 20, the sealant layer 13 ruptures at the boundary between the peripheral sealing area 10b and the opening area 10c. In the opening area 10c, the sealant layer 13 peels off from the container 20 together with the base sheet 11 and the adhesive layer 12. In Figure 2(b), the sealant layer 13 that has been peeled off from the container 20 is indicated by the reference numeral " ₁₃₁ ".

As the delamination between the lid material 10 and the container 20 progresses further, this delamination reaches the peripheral seal region 10b again. This is the opening-side peripheral seal region 10b _1. In this opening-side peripheral seal region 10b ₁ , the sealant layer 13 of the lid material 10 and the container 20 are sealed to each other. Therefore, the sealant layer 13 again breaks at the boundary between the opening-corresponding region 10c and the opening-side peripheral seal region 10b _1. In the opening-side peripheral seal region 10b ₁ , the adhesive layer 12 delaminates between the adhesive layer 12 and the sealant layer 13 and is peeled off together with the base sheet 11, while the sealant layer 13 remains on the container 20 side. In Figure 2(b), the reference numeral " ₁₃₂ " indicates the sealant layer 13 remaining on the container 20 side. The adhesive layer 12 is exposed on the surface of the delaminated lid material 10, on the side facing the container 20 (the container-side surface).

As mentioned above, the periphery 22 of the container opening is provided in a closed curve shape surrounding the opening-corresponding region 10c. Therefore, including the opening-side periphery sealing region 10b ₁ , the periphery sealing region 10b is configured in a closed curve shape surrounding the opening-corresponding region 10c.

Next, the separation of the lid material 10 from the container 20 reaches the terminal welding portion 10y. At the terminal welding portion 10y, the base sheet 11 of the lid material 10, the sealant layer 13, and the container 20 are integrally welded together. The force required to break the welding between the base sheet 11 and the sealant layer 13 or between the sealant layer 13 and the container 20 and separate the lid material 10 is greater than the force required to separate the adhesive layer 12 and the sealant layer 13 in the opening-side peripheral seal region 10b _1. If the force pulling the lid material 10 upward is greater than the force required to separate the adhesive layer 12 and the sealant layer 13, and less than the force required to break the welding between the base sheet 11 and the sealant layer 13 or between the sealant layer 13 and the container 20, the separation of the lid material 10 from the container 20 ends here and does not proceed any further. In other words, the lid material 10 is not peeled off in the terminal peripheral sealing region 10b ₂ and remains connected to the container 20.

Furthermore, the contents can be removed through the opened opening 21.

Incidentally, as can be seen from Figures 2(a) and (b), the detached lid material 10 is in the same state as when it has been rotated around the terminal peripheral seal region 10b ₂ as the pivot axis. Therefore, by rotating the lid material 10 back to its original position and re-adhering the adhesive layer 12 ₂ exposed in the peripheral seal region 10b, including the opening-side peripheral seal region 10b ₁ , to the sealant layer 13 ₂ remaining on the container 20 side, the container 20 can be closed again. This opening and closing can be repeated many times.

Furthermore, in this packaging A, in order to peel the lid 10 from the container 20 and open it, the tab weld portion 10x, where the base sheet 11, sealant layer 13, and container 20 are integrally welded together, must be broken. The broken portion cannot be restored, and since a trace of the break remains, it is possible to distinguish between a used, opened package and an unopened, never-opened package.

Furthermore, even if one attempts to open this packaging A by peeling off the lid material 10 from the end-side peripheral seal area 10b ₂ , the end-side welded portion 10y is located in this end-side peripheral seal area 10b _2. In this end-side welded portion 10y, just like the tab welded portion 10x, the base sheet 11, the sealant layer 13, and the container 20 are integrally welded together. Therefore, the torn portion cannot be restored, and a trace of the tear remains, making it possible to distinguish between a package that has been opened and used and an unopened package that has never been opened.

The first embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the gist of the present invention. Furthermore, the components shown in the above-described embodiment and the following modifications can be combined as appropriate.

(Second embodiment)
Next, Figure 3 shows a second embodiment in which a container 30 is used, whose opening spans two surfaces. In this case as well, the lid material 10 is sealed around the periphery of the opening to close it, so that it can be opened and closed repeatedly, just like in the first embodiment. It is also possible to distinguish between containers that have been opened and used and those that have never been opened and remain unopened.

(Third embodiment)
Figure 4 shows a third embodiment in which a container 40 formed by a deep drawing method such as vacuum forming is used as the container. The container 40 has an opening on its top surface. The opening has a flange around its periphery. In this case as well, the lid material 10 is sealed to the flange around the opening so as to close the opening, so that it can be opened and closed repeatedly, as in the first embodiment. As shown in the figure, the tab 10a can be folded and sealed along the body of the container 40. In this example as well, it is possible to distinguish between a container that has been opened and used and an unopened container that has never been opened.

(Fourth embodiment)
Figure 5 shows a fourth embodiment in which a paper cup 50 is used as the container. The paper cup 50 also has an opening on its top surface, and a flange is provided around the opening by wrapping the sheet that makes up the body around the outside of the opening. In this case as well, the lid material 10 is sealed to the flange around the opening so as to close the opening, so that it can be opened and closed repeatedly as in the first embodiment. As shown in the figure, the tab 10a can be folded and sealed along the body of the paper cup 50. In this example as well, it is possible to distinguish between a cup that has been opened and used and an unopened cup that has never been opened.

(Fifth Embodiment)
Next, Figure 6 shows a packaging body E of a fifth embodiment in which a rectangular cup-shaped container 60 is used as the container. As the rectangular cup-shaped container 60, resin containers such as polystyrene or polypropylene, or paper containers can be used, such as paper cups, milk cartons, and sake cartons, which are made by molding synthetic resin processed paper by laminating a synthetic resin film or metal foil onto cup base paper or cardboard.

The rectangular cup-shaped container 60 has a substantially rectangular opening 61 on its upper surface. A flange 63 is provided around the periphery 62 of the opening 61.

The rectangular cup-shaped container 60 is filled with a liquid substance (not shown), such as yogurt. However, the contents are not limited to this embodiment and may include other fermented dairy products, fermented milk, coffee, or other beverages.

The lid material 10p is heat-sealed, for example, to the flange 63 of the peripheral edge 62 to close the opening 61. The lid material 10p is constructed by laminating a base sheet 11, an adhesive layer 12, and a sealant layer 13 in the same order as in the first embodiment. In this embodiment, the lid material 10p is used for a rectangular cup-shaped container 60 filled with yogurt as the contents. Therefore, the rectangular cup-shaped container 60 and the lid material 10p can be those that conform to the Ministerial Ordinance on Milk and Dairy Products (Ministerial Ordinance on Standards for Ingredients of Milk and Dairy Products, Ministry of Health and Welfare Ordinance No. 52 of December 27, 1951).
For example, the rectangular cup-shaped container 60 can be made of a resin such as polystyrene or polypropylene, or a paper container made by molding synthetic resin-processed paper. The lid material 10p is made of a material containing aluminum (AL) or the like.

In this embodiment, the adhesive layer 12 may be a hot-melt adhesive primarily composed of a thermoplastic polymer. When using a hot-melt adhesive, for example, the lid material 10p is formed by extrusion lamination, where the molten thermoplastic adhesive layer 12 is extruded from a T-die and pressed onto the base sheet 11 and the sealant layer 13.

The lid material 10p can be divided into several regions depending on its positional relationship with the rectangular cup-shaped container 60, similar to the first embodiment. As shown in Figures 6 and 7, the tab 10a, similar to the fourth embodiment, is provided on the lid material 10, protruding outward from the peripheral edge 62, and is folded and sealed along the body of the rectangular cup-shaped container 60. However, in this embodiment, the entire tab 10a is not sealed to the rectangular cup-shaped container 60; only the tab welding portion 10x is sealed to the rectangular cup-shaped container 60 by strong heat and pressure.

Furthermore, as shown in Figure 7, the lid material 10p, similar to the first embodiment, has the following regions provided in order from the tab 10a on one side of the lid material 10p, straddling the center of the lid material 10p, toward the opposite side: a peripheral sealing region 10b, an opening corresponding region 10c, and another peripheral sealing region 10b. In addition, the peripheral sealing region 10b on the opposite side of the peripheral 62 of the lid material 10p is provided with an end-side welding portion 10y, which is subjected to strong heat and pressure on the lid material 10p, similar to the tab welding portion 10x. The packaging body E can be opened by peeling the lid material 10 from the rectangular cup-shaped container 60 using the same opening method as in the first embodiment. In this embodiment, the peripheral sealing region 10b is a single region, but similar to the first embodiment, it may be divided into two regions: an opening-side peripheral sealing region 10b ₁ and an end-side peripheral sealing region 10b ₂ .

In this embodiment, the lid material 10p is heat-sealed to the flange 63 of the peripheral edge 62 so as to close the opening 61. Therefore, it is possible to prevent the liquid yogurt contents from leaking out of the opening 61.

In this embodiment, since the adhesive layer 12 is not present in the tab welding portion 10x of the tab 10a region, either the welding between the base sheet 11 and the sealant layer 13 or the welding between the sealant layer 13 and the container 20 is broken, causing the lid material 10p to peel off from the rectangular cup-shaped container 60. In this embodiment, as shown in Figure 8, the welding between the base sheet 11 and the sealant layer 13 breaks, causing the lid material 10p to peel off from the rectangular cup-shaped container 60. As a result, the packaging E cannot restore the peeled portion of the sealant layer 13, leaving a trace. Therefore, the packaging E can be distinguished from one that has been opened and used, and from an unopened one that has never been opened. Note that the peeled portion is not particularly limited; it may also occur when the welding between the sealant layer 13 and the rectangular cup-shaped container 60 breaks.

Furthermore, in this embodiment, the lid material 10 peels off between the adhesive layer 12 and the sealant layer 13 in the peripheral sealing region 10b, as shown in Figure 8. The sealant layer 13 remains on the side of the rectangular cup-shaped container 60, while the adhesive layer 12 peels off together with the base sheet 11. Since the adhesive layer 12 ₂ is exposed on the surface of the lid material 10p facing the rectangular cup-shaped container 60, the lid material 10p can be resealed by re-adhering the adhesive layer 12 ₂ to the sealant layer 13 _2. Therefore, for example, in a yogurt container, it is possible to eliminate the cover lid or the like that was conventionally provided above the lid material 10p to prevent the contents from spilling out.

Furthermore, in this embodiment, in the opening-corresponding region 10c, the sealant layer 13 peels off from the rectangular cup-shaped container 60 together with the base sheet 11 and the adhesive layer 12. Subsequently, the peeling of the lid material 10p from the rectangular cup-shaped container 60 reaches the terminal welding portion 10y provided in the peripheral seal region 10b. However, strong heat and pressure are applied to the terminal welding portion 10y from the lid material 10p. In the terminal welding portion 10y, similar to the first embodiment, the base sheet 11 of the lid material 10, the sealant layer 13, and the rectangular cup-shaped container 60 are integrally welded together. Note that the force required to break the welding between the base sheet 11 and the sealant layer 13 or between the sealant layer 13 and the rectangular cup-shaped container 60 and peel off the lid material 10 is greater than the force required to peel between the adhesive layer 12 and the sealant layer 13 in the peripheral seal region 10b. If the force pulling the lid material 10p upward is greater than the force required to separate the adhesive layer 12 and the sealant layer 13, and less than the force required to break the weld between the base sheet 11 and the sealant layer 13 or the weld between the sealant layer 13 and the container 20, then the separation of the lid material 10p from the rectangular cup-shaped container 60 ends at the terminal weld portion 10y and does not proceed any further. Therefore, the lid material 10p is not separated and can remain connected to the rectangular cup-shaped container 60. However, if the force pulling the lid material 10p upward is greater than the force required to break the weld between the base sheet 11 and the sealant layer 13 or the weld between the sealant layer 13 and the container 20, then the lid material 60 breaks and separates at the terminal weld portion 10y. Since the torn portion cannot be restored and a trace of the break remains, packaging E can be distinguished from packaging that has been opened and used, and from packaging that has never been opened.

In any of the above embodiments, the packaging according to the present invention comprises a container having an opening and a lid material sealed around the periphery of the opening to close it, and provides a packaging that can be opened and closed repeatedly, and has a tamper-evident function.

(experiment)
Next, an experiment was conducted to measure the peel strength in the peripheral sealing area 10b and the tab welding area 10x of the lid material 10p of the packaging body E according to the fifth embodiment, in order to confirm that the force required to break the weld between the base sheet 11 and the sealant layer 13 or the force required to break the weld between the sealant layer 13 and the rectangular cup-shaped container 60 is greater than the force required to peel between the adhesive layer 12 and the sealant layer 13. Note that the tab welding area 10x may also be measured in the area of the terminal welding area 10y, where strong heat pressure is applied to the lid material 10p in the same way as the tab welding area 10x.

The experimenter, similar to the first embodiment, grasps the tab of the lid material 10p and pulls it upward to open the packaging. The experimenter applies a tensile force (300 mm/min) in the opposite direction from the direction of mutual welding, separating the rectangular cup-shaped container 60 from the lid material 10p. At this time, the required peel strength (N/15 mm) is measured for the peripheral seal area 10b and the tab welding portion 10x. The obtained measurement results are shown in Table 1. Here, peel strength refers to the strength of the welded portion when the rectangular cup-shaped container 60 and the lid material 10p are separated, and is the strength of the welded portion between the base sheet 11 and the sealant layer 13, the welded portion between the sealant layer 13 and the rectangular cup-shaped container 60, or the welded portion between the adhesive layer 12 and the sealant layer 13.

In this case, the lid material 10p was made from the constituent materials listed in Table 1.
Specifically, experiments were conducted using a laminated material (Reseal Sealant: Diamilon® MF RE) made by laminating a 12 μm thick biaxially oriented polyethylene terephthalate (PET) film with a printed layer (ink) on one side by gravure printing, a 7 μm thick aluminum foil (AL), an adhesive layer, and a sealant layer in that order, with a 60 μm thick co-extruded film, using a dry lamination method with polyester urethane adhesive. As shown in Table 1, the required peel strength in the peripheral seal area 10b was 8.6 N/15 mm. The required peel strength in the tab welded area 10x was 11.7 N/15 mm.

From the above results, it was found that the required peel strength in the tab-welded area 10x is higher than the required peel strength in the peripheral seal area 10b. The tab-welded area 10x is the area where strong heat and pressure are applied to the lid material 10p, causing the adhesive layer 12 to be thinned. In other words, it was confirmed that the force required to break the tab-welded area 10x, where the base sheet 11 and the sealant layer 13 are welded together or the sealant layer 13 and the rectangular cup-shaped container 60 are welded together, is greater than the force required to peel between the adhesive layer 12 and the sealant layer 13 in the peripheral seal area 10b. Therefore, it can be concluded that the rectangular cup-shaped container 60 and the lid material 10p are separated and opened at the tab-welded area 10x by the breakage of the weld between the base sheet 11 and the sealant layer 13, or by the breakage (paper peeling) of the weld between the sealant layer 13 and the rectangular cup-shaped container 60. Furthermore, it can be considered that the rectangular cup-shaped container 60 and the lid material 10p are separated from each other between the adhesive layer 12 and the sealant layer 13 in the peripheral sealing region 10b.

The packaging according to the present invention consists of a container having an opening and a lid material sealed around the periphery of the opening to close it. Since the opening and closing can be repeated many times, it is industrially applicable.

A: Packaging according to the first embodiment 10: Lid material 11: Base sheet 12: Adhesive layer 13: Sealant layer 10a: Tab 10b: Peripheral sealing area 10c: Opening corresponding area 10x: Tab welding part 10y: End welding part 20: Container (pillow bag)
B: Packaging according to the second embodiment 30: Container (pillow bag)
C: Packaging according to the third embodiment 40: Container (drawn container)
D: Packaging according to the fourth embodiment 50: Container (paper cup)
E: Packaging according to the fifth embodiment 10p: Lid material 60: Container (rectangular cup-shaped container)

Claims (7)

A container having an opening,
The periphery of the opening is sealed to close the opening,
A heat-sealable base sheet,
Adhesive layer,
The sealant layer,
A lid material having the above, and constructed by laminating the base sheet, the adhesive layer, and the sealant layer in this order,
Equipped with,
The lid material has a tab that protrudes outward from the seal line formed on the periphery of the opening,
The adhesive layer and the sealant layer are capable of repeated peeling and re-adhesion between them.
The packaging is characterized in that at least a portion of the tab is provided with a tab-welded portion in which the base sheet and the sealant layer are welded together without the adhesive layer in between. The packaging according to claim 1, characterized in that the sealant layer and the container are welded together at the tab welding portion. The packaging according to claim 1 or 2, characterized in that, at the periphery of the opening, at least a portion of the area opposite to the tab provided on one side of the lid material, straddling the center of the lid material, is provided with an end-side welded portion where the base sheet and the sealant layer are welded together without the adhesive layer. The packaging according to claim 1 or 2, characterized in that the opening is formed in the container spanning two surfaces. The aforementioned opening is provided with a flange on its periphery.
The packaging body according to claim 1 or 2, characterized in that the lid material is sealed to the flange. The opening is provided with a flange formed by wrapping the sheet constituting the body around the outside of the opening at its periphery.
The packaging body according to claim 1 or 2, characterized in that the lid material is sealed to the flange. The adhesive layer is thermoplastic,
The packaging body according to claim 1 or 2, characterized in that the lid material is formed by extrusion lamination, in which the adhesive layer is pressed onto the base sheet and the sealant layer.