Packaging

Abstract

To propose a package that allows for re-sealing after unsealing and pressure cooking in heating with an electronic oven and moreover is not to pose a danger of burst or explosion.SOLUTION: A package 1 includes a container body 2 having an opening 3 sealed by a lid material 4. The lid material has a second opening 6 formed by an U-shaped cutout 5, in which the second opening in its entirety is sealed by an adhesive sheet 7. By removing the adhesive sheet from a bottom direction of an U-shape of the U-shaped cutout, the second opening can be opened. At a side end of the adhesive sheet, a cutout 9 having a length longer than 10 mm and penetrating through an entire thickness of the adhesive sheet is provided cooperatively with a side end of the second opening. The cutout is positioned 3 mm or more inner than the side end of the adhesive sheet and within 7 mm. When the adhesive sheet is once removed and re-sealed, adhesion strength is 2 N / 15 mm or smaller.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a package for storing mainly food items, which can be resealed after opening and can be heated directly in a microwave oven. [Background technology]

[0002] Plastic containers are widely used as containers for storing food. In particular, for containers for storing frozen foods, it would be convenient if the food could be defrosted and heated in a microwave oven after being taken out of the freezer. In this case, if a normal container is used, there is a risk that the container may burst or explode due to the steam generated by heating.

[0003] In order to prevent such dangers, the frozen food storage container described in Patent Document 1 is a container in which the steam release opening automatically opens when heated. The frozen food storage container described in Patent Document 1 has a label that has a large thermal shrinkage rate when heated attached to the steam release opening, and when heated in a microwave oven, the label shrinks and the steam release opening opens, preventing explosions and ruptures.

[0004] Meanwhile, in recent years, as cooking methods using microwave ovens have become more diverse, attention has been drawn to cooking methods such as opening the container once, adding ingredients and seasonings, and then cooking in the microwave oven, and pressurized cooking, which achieves a high cooking effect by applying a certain amount of pressure during heating. The frozen food storage container described in Patent Document 1 could not meet such demands. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-278975 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a package that can be resealed after opening, that can be pressure-cooked when heated in a microwave oven, and that does not pose a risk of bursting or explosion. [Means for solving the problem]

[0007] As a means for solving the above problem, the invention described in claim 1 is a packaging body in which an opening of a container body is sealed with a lid material, the lid material has a second opening formed by a U-shaped notch, the entire second opening is sealed with an adhesive sheet, the second opening can be opened by peeling the adhesive sheet from the bottom direction of the U-shaped notch, a notch longer than 10 mm is provided at the side end of the adhesive sheet between the side end of the second opening and the side end of the adhesive sheet, the position of the notch is at least 3 mm inside and within 7 mm, and the adhesive strength when the adhesive sheet is peeled off and resealed is 2 N / 15 mm or less.

[0008] The packaging body of the present invention has a second opening covered with an adhesive sheet, so that it can be opened once, ingredients etc. can be added, and then resealed and cooked in a microwave oven; the notches in the lid material and adhesive sheet help to avoid the risk of rupture or explosion.

[0009] The invention described in claim 2 is a packaging body in which an opening of a container body is sealed with a lid material, the lid material has a second opening formed by a U-shaped notch, the entire second opening is sealed with an adhesive sheet, the second opening can be opened by peeling the adhesive sheet from the bottom of the U-shaped notch, the lid material has a notch that penetrates the lid material and is longer than 10 mm between the side edge of the second opening and the side edge of the adhesive sheet, the position of the notch is at least 3 mm inside and within 7 mm of the side edge of the adhesive sheet, and the adhesive strength when the adhesive sheet is peeled off and resealed is 2 N / 15 mm or less.

[0010] The invention described in claim 3 is the package described in claim 1 or 2, characterized in that the lid material and the adhesive sheet include a gas barrier layer that does not include a metal foil or a metal vapor deposition layer.

[0011] The invention described in claim 4 is a packaging body described in any one of claims 1 to 3, characterized in that the adhesive sheet has a tab for peeling from the bottom direction of the U-shaped notch. Effect of the Invention

[0012] The package according to the present invention has a second opening covered with an adhesive sheet, so that it can be opened once, ingredients and the like can be put in, and then resealed and cooked in a microwave oven. In addition, even if the package is heated in a resealed state, the slits in the lid and adhesive sheet allow the generated water vapor to be released through the slits, preventing the package from bursting or exploding.

[0013] By keeping the adhesive strength of the adhesive sheet after resealing at 2N / 15mm or less, steam release performance is ensured, and by adjusting the position of the cut, pressure cooking can be achieved. [Brief description of the drawings]

[0014] [Figure 1]FIG. 1 is a schematic plan view showing a first embodiment of a package according to the present invention. [Diagram 2] FIG. 2 is a schematic side view of the package shown in FIG. [Diagram 3] FIG. 3 is an explanatory side view showing the package shown in FIGS. 1 and 2 in an opened state. [Figure 4] FIG. 4 is a schematic plan view of the lid member of the package shown in FIGS. [Diagram 5] FIG. 5 is a schematic plan view of the adhesive sheet of the package shown in FIGS. [Figure 6] FIG. 6 is a schematic plan view showing a second embodiment of a package according to the present invention. [Figure 7] FIG. 7 is a schematic side view of the package shown in FIG. [Figure 8] FIG. 8 is an explanatory side view showing the state in which the package shown in FIGS. 6 and 7 has been opened. [Figure 9] FIG. 9 is a schematic plan view of the lid member of the package shown in FIGS. [Figure 10] FIG. 10 is a schematic plan view of the adhesive sheet of the package shown in FIGS. [Figure 11] FIG. 11 is an explanatory diagram showing a state in which water vapor is emitted when the package shown in FIG. 1 is heated in a microwave oven. [Figure 12] FIG. 12 is an explanatory diagram showing a state in which water vapor is emitted when the package shown in FIG. 6 is heated in a microwave oven. [Figure 13] FIG. 13 is an explanatory diagram showing the length and position of the cuts. [Figure 14] FIG. 14 is a cross-sectional explanatory view showing an example of the layer structure of the lid material of the packaging body according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The package according to the present invention will be described in detail below with reference to the drawings. Fig. 1 is a schematic plan view showing a first embodiment of a package 1 according to the present invention. Fig. 2 is a schematic side view of the package shown in Fig. 1. Fig. 3 is an explanatory side view showing the package shown in Figs. 1 and 2 in an opened state. Fig. 4 is a schematic plan view of a lid member 4 of the package shown in Figs. 1 and 2. Fig. 5 is a schematic plan view of an adhesive sheet 7 of the package shown in Figs. 1 and 2.

[0016] A first embodiment of the packaging body 1 according to the present invention is a packaging body in which an opening 3 of a container body 2 is sealed with a lid material 4, the lid material 4 has a second opening 6 formed by a U-shaped notch 5, the entire second opening is sealed with an adhesive sheet 7, the second opening 6 can be opened by peeling the adhesive sheet 7 from the bottom direction of the U-shaped notch, a notch 9 having a length of more than 10 mm that penetrates the entire thickness of the adhesive sheet is provided between the side end of the adhesive sheet 7 and the side end of the second opening 6, the position of the notch 9 is at least 3 mm inside and within 7 mm from the side end of the adhesive sheet 7, and the adhesive strength when the adhesive sheet 7 is peeled off and resealed is 2 N / 15 mm or less.

[0017] The package 1 according to the present invention has a structure in which a second opening 6 formed by a U-shaped cut 5 is provided in a lid member 4 that seals an opening 3 of a container body 2, and this second opening 6 is sealed with an adhesive sheet 7, so that it is possible to open the second opening 6 by peeling off the adhesive sheet 7 from the bottom direction of the U-shaped cut 5. Since the adhesive sheet 7 can be resealed even once opened, for example, the package 1 can be opened, ingredients, seasoning liquid, etc. can be poured in through the second opening 6, and then the package can be resealed and cooked in a microwave oven.

[0018] Fig. 3 is an explanatory side view showing the state in which the package shown in Fig. 1 and 2 has been opened. It shows the state in which the second opening 6 has been opened by peeling off the adhesive sheet 7 from the bottom direction of the U-shaped cut.

[0019] In the package 1 of the present invention, a slit 9 is provided in the adhesive sheet 7, so that when the resealed package is heated in a microwave oven, the generated water vapor escapes through this slit 9, preventing the package from rupturing or exploding.

[0020] FIG. 11 is an explanatory diagram showing the state in which water vapor S is emitted when the package 1 shown in FIG. 1 is heated in a microwave oven. When the package 1 is heated, the internal moisture evaporates and water vapor is generated. The entire container is deformed and bulges outward due to the pressure of the water vapor. The adhesive sheet 7 is left behind because the adhesive layer softens and becomes slippery, and as a result, the U-shaped cut 5 formed in the lid material 4 intersects with the cut 9 formed in the adhesive sheet 7. Water vapor S is emitted from here, preventing the container from bursting or exploding.

[0021] At this time, if the adhesive strength of the adhesive sheet 7 is too strong, it becomes difficult for water vapor to escape, so when the adhesive sheet 7 is peeled off and resealed, the adhesive strength must be 2N / 15mm or less. .

[0022] Fig. 5 is a schematic plan view of the adhesive sheet 7 of the package 1 shown in Figs. 1 and 2. In this example, a tab 8 is provided to serve as a handle when peeling off the adhesive sheet 7, and a notch 9 is provided at the side edge. It has been experimentally clarified that the notch 9 is a notch that penetrates the entire thickness of the adhesive sheet 7, is longer than 10 mm, and is located at a position 3 mm or more inward and within 7 mm of the side edge of the adhesive sheet 7.

[0023] The tab portion of the adhesive sheet 7 can be realized by not providing an adhesive layer in only this portion, or by providing a coating layer on the adhesive that inhibits adhesion.

[0024] In addition, a second embodiment of the packaging body 1 according to the present invention is a packaging body in which the opening 3 of the container body 2 is sealed with a lid material 4, the lid material 4 has a second opening 6 formed by a U-shaped notch 5, the entire second opening is sealed with an adhesive sheet 7, the second opening 6 can be opened by peeling the adhesive sheet 7 from the bottom direction of the U-shaped notch, the lid material 4 has a notch 9 longer than 10 mm that penetrates the lid material between the side end of the second opening 6 and the side end of the adhesive sheet 7, the position of the notch 9 is at least 3 mm inside and within 7 mm from the side end of the adhesive sheet, and the adhesive strength when the adhesive sheet 7 is peeled off and resealed is 2 N / 15 mm or less.

[0025] Fig. 6 is a schematic plan view showing a package 1 according to this embodiment. Fig. 7 is a schematic side view of the package shown in Fig. 6. Fig. 8 is an explanatory side view showing the package 1 shown in Figs. 6 and 7 in an opened state. Fig. 9 is a schematic plan view of a lid member 4 of the package shown in Figs. 6 and 7. Fig. 10 is a schematic plan view of an adhesive sheet 7 of the package shown in Figs. 6 and 7.

[0026] In the first embodiment described earlier, a notch 9 was provided in the adhesive sheet 7, but in this embodiment, as shown in FIG. 10, no notch is provided in the adhesive sheet 7, and instead, as shown in FIG. 9, a notch 9 is provided in the lid material 4.

[0027] In this case, experiments have shown that the length of the cut 9 must be greater than 10 mm, and that the cut must be located at least 3 mm inward and within 7 mm of the side edge of the adhesive sheet 7.

[0028] Moreover, the adhesive strength of the adhesive sheet 7 must be 2N / 15mm or less when the adhesive sheet 7 is once peeled off and then resealed.

[0029] Fig. 12 is an explanatory diagram showing the state in which water vapor S is emitted when the package 1 shown in Fig. 6 is heated in a microwave oven. When the package 1 is heated, the internal moisture evaporates and water vapor is generated. The entire container is deformed and bulges outward due to the pressure of the water vapor. The adhesive sheet 7 is left behind because the adhesive layer softens and becomes slippery, and as a result, the cut 9 formed in the lid material 4 is released from the adhesive sheet 7 and exposed. Water vapor S is emitted from here, preventing the container from bursting or exploding.

[0030] 13 is an explanatory diagram showing the length L and position of the incision 9. The position can be determined by the distance d from the side edge of the adhesive sheet 7. In both the first and second embodiments, it has been found that the length of the incision 9 needs to be longer than 10 mm.

[0031] Regarding the position of the cut 9, in the first embodiment, if d is too short, i.e., if it is too close to the side edge of the adhesive sheet 7, the water vapor will not escape well and will not escape through the original cut and will be stuck to the seal area. The steam will escape from the sealing portion. Conversely, if d is too long, the steam will escape too easily, and pressure cooking may be insufficient. On the other hand, in the second embodiment, if d is too short, i.e., if the cut 9 in the lid material 4 is too close to the side edge of the adhesive sheet 7, the steam will escape too easily, and pressure cooking may be insufficient. Conversely, if d is too long, the steam will not escape easily, and will escape from the sealed portion instead of escaping through the original cut.

[0032] The materials used for the packaging body according to the present invention will be described below. There are no particular restrictions on the container body 2, but if heating in a microwave oven is assumed, it is desirable to use a material with high heat resistance. Specific examples include polypropylene resin, polyethylene terephthalate resin, polyamide resin, etc. There are also no particular restrictions on the molding method, and molding methods such as vacuum molding, vacuum pressure molding, and injection molding can be used.

[0033] The lid material 4 is also required to have a certain level of heat resistance. When long-term storage of the contents is required, it is desirable to include a gas barrier layer that suppresses the transmission of water vapor and oxygen. FIG. 14 is a cross-sectional explanatory diagram showing an example of the layer structure of the lid material 4 of the package according to the present invention. In this example, a gas barrier layer 11 is inserted in addition to a base layer 10 and a sealant layer 12. The lid material 4 used in the package according to the present invention is required to be heated in a microwave oven, so that the gas barrier layer 11 does not need to include a metal foil or a metal vapor deposition layer.

[0034] Examples of such gas barrier layers include gas barrier films such as polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, gas barrier nylon film, and gas barrier polyethylene terephthalate (PET) film; inorganic oxide vapor-deposited films in which inorganic oxides such as aluminum oxide and silicon oxide are vapor-deposited onto a PET film; and gas barrier coating layers such as polyvinylidene chloride coating, a coating containing a water-soluble resin and an inorganic layered compound, or a resin layer formed by reacting a metal alkoxide or its hydrolysate with an isocyanate compound. The packaging body according to the present invention will be described more specifically below based on examples and comparative examples.

[0035] <Example 1> The container body was made of polypropylene resin and had the shape shown in Figures 1 and 2. The long side was 250 mm, the short side was 110 mm, and the height was 30 mm. The width of the flange was 10 mm. The lid material used was a laminate of a gas barrier film (GL-PET, 12 μm thick, manufactured by Toppan Printing Co., Ltd.) with an inorganic oxide vapor deposition and a 30 μm thick non-oriented polypropylene resin film (CPP). The adhesive sheet used was a laminate of 20μm vinylidene chloride coated oriented polypropylene resin film (KOP) and 50μm oriented polypropylene resin film (OPP) with an acrylic resin adhesive applied to the OPP surface. The adhesive strength of the adhesive sheet after resealing was 1N / 15mm.

[0036] A U-shaped cut was formed in the lid as shown in Figure 4. The length of the U-shape was 150 mm, and the width of the U-shape was 70 mm. According to the first embodiment, no cut was provided in the lid. A cut was provided in the adhesive sheet as shown in Figure 5. The length L of the cut was 30 mm, and the position d of the cut was 3 mm. The length of the adhesive sheet was 180 mm, and the width was 90 mm.

[0037] The lid was heat sealed to the container body and an adhesive sheet was attached, after which the adhesive sheet was peeled off together with the lid. 150g of chicken and seasoning liquid were added through the second opening and the container was resealed. The container was then heated in a 600W microwave for 5 minutes and the condition was observed and evaluated.

[0038] <Example 2> A package was prepared in the same manner as in Example 1, except that the position d of the cut in the adhesive sheet was set to 5 mm, and was evaluated in the same manner.

[0039] <Example 3> A package was prepared in the same manner as in Example 1, except that the position d of the cut in the adhesive sheet was set to 7 mm, and was evaluated in the same manner.

[0040] <Example 4> A package was prepared in the same manner as in Example 1, except that the length L of the cut in the adhesive sheet was 20 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0041] <Example 5> A package was prepared in the same manner as in Example 1, except that the length L of the cut in the adhesive sheet was 40 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0042] <Example 6> Using the same materials as in Example 1, a prototype was produced and evaluated based on the second embodiment in which a cut was made in the lid material and no cut was made in the adhesive sheet. As shown in Figure 9, a U-shaped cut and two cuts were made in the lid material. The length L of the cut was 30 mm, and the position d was 3 mm. No cut was made in the adhesive sheet, as shown in Figure 10. Thereafter, a package was produced in the same manner as in Example 1, and evaluated in the same manner.

[0043] <Example 7> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 30 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0044] <Example 8> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 30 mm and the position d was 7 mm, and was evaluated in the same manner.

[0045] <Example 9> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 20 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0046] <Example 10> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 40 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0047] <Comparative Example 1> A package was prepared in the same manner as in Example 1, except that the length L of the cut in the adhesive sheet was 30 mm and the position d was 1 mm, and was evaluated in the same manner.

[0048] <Comparative Example 2> A package was prepared in the same manner as in Example 1, except that the length L of the cut in the adhesive sheet was 30 mm and the position d was 9 mm, and the package was evaluated in the same manner.

[0049] <Comparative Example 3> The length L of the cut in the adhesive sheet was 10 mm, and the position d was 5 mm. A package was prepared in the same manner as in Example 1 and evaluated in the same manner.

[0050] <Comparative Example 4> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 30 mm and the position d was 1 mm, and was evaluated in the same manner.

[0051] <Comparative Example 5> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 30 mm and the position d was 9 mm, and the package was evaluated in the same manner.

[0052] <Comparative Example 6> A package was prepared in the same manner as in Example 6, except that the length L of the cut formed in the lid material was 10 mm and the position d was 5 mm, and the package was evaluated in the same manner.

[0053] The above results are summarized in Table 1.

[0054] [Table 1]

[0055] The results in Table 1 show that the package according to the present invention can be pressure-cooked in a microwave oven after the adhesive sheet is removed and resealed, without any risk of rupture or explosion. [Explanation of symbols]

[0056] 1...packaging 2. Container body 3. Opening 4...Lid material 5. U-shaped notch 6...Second opening 7. Adhesive sheet 8. Knob part 9. Cutting 10...Base material layer 11. Gas barrier layer 12. Sealant layer L: Length of cut d. Cutting position S...Water vapor

Claims

1. A package in which an opening of a container body is sealed with a lid material, The lid has a second opening formed by a U-shaped cut, The entire second opening is sealed with an adhesive sheet, the second opening can be opened by peeling the adhesive sheet from a bottom direction of the U-shaped notch, a cut having a length of more than 10 mm is provided between the side edge of the adhesive sheet and the side edge of the second opening, the cut penetrating the entire thickness of the adhesive sheet; The position of the cut is 3 mm or more and 7 mm or less inside from the side edge of the adhesive sheet, A package characterized in that the adhesive strength when the adhesive sheet is once peeled off and resealed is 2N / 15mm or less.

2. A package in which an opening of a container body is sealed with a lid material, The lid has a second opening formed by a U-shaped cut, The entire second opening is sealed with an adhesive sheet, the second opening can be opened by peeling the adhesive sheet from a bottom direction of the U-shaped notch, the lid member has a cut extending through the lid member and having a length of more than 10 mm between a side edge of the second opening and a side edge of the adhesive sheet; The position of the cut is 3 mm or more and 7 mm or less inside from the side edge of the adhesive sheet, A package characterized in that the adhesive strength when the adhesive sheet is once peeled off and resealed is 2N / 15mm or less.

3. 3. The package according to claim 1, wherein the cover material and the adhesive sheet include a gas barrier layer that does not include a metal foil or a metal vapor deposition layer.

4. 4. The packaging body according to claim 1, wherein the adhesive sheet has a tab for peeling from a bottom of the U-shaped cut.

Images