JPH0435158Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention is a packaging body using aluminum foil having a heat sealing layer as a material for forming a container body and a lid which are bonded together by heat sealing. The present invention relates to a packaging body that can be used for sealed packaging of foods and drugs containing lactic acid, such as yogurt mousse and yogurt jelly, which have corrosive properties. [Prior art and problems to be solved] This type of packaging is required to have at least the following properties. First, it is necessary that the aluminum foil from which the package is formed is not corroded by the contents, that is, it must have excellent corrosion resistance. Next, the sealing performance of the heat-sealed seal between the container body and the lid should be good, that is, the seal should not come off due to air expansion inside the package. Furthermore, in order to prevent an increase in the internal pressure of the package during heat sealing, it is also required to have low temperature sealability. In addition, when taking out the contents from the package, there is a requirement for easy opening, which means that the package can be easily opened by hand and can be opened cleanly without leaving any resin film on the lid on the container body. It is. However, conventional packaging bodies made of aluminum foil having a heat-sealing layer do not satisfy all of the above properties. Therefore, this invention attempts to obtain a package that satisfies all of the above properties by creating a predetermined layer structure for the aluminum foil composite material that forms the lid and container body. be. [Means for Solving the Problems] In order to solve the above problems, this invention provides a packaging body with a protective layer on the outer surface and an adhesive layer of ethylene acrylic acid emulsion or ionomer emulsion on the inner surface. The lid or container body is formed from aluminum foil having an ionomer resin layer, and the outer surface has a protective layer, and the inner surface is coated with styrene graft modified polyethylene resin through an adhesive layer of ethylene acrylic acid emulsion or ionomer emulsion. The container main body or lid is formed of aluminum foil having a layer, and the ionomer resin layer and the modified polyethylene resin layer are sealed by heat sealing. [Function] With the above configuration, the adhesive surface between the lid and the container body is a combination of an ionomer resin layer and a modified polyethylene resin layer.The heat sheet can be sealed at low temperatures, and does not cause wrinkles in the sealing part, resulting in excellent sealing performance. Excellent. In addition, by adhering the ionomer resin layer and the modified polyethylene resin layer to the aluminum foil through an adhesive layer of ethylene acrylic acid emulsion or ionomer emulsion, the ionomer resin layer and the modified polyethylene resin layer can be attached to the aluminum foil. Strong adhesion allows for good easy opening. [Example] Hereinafter, an example of this invention will be described based on the accompanying drawings. The package of this invention consists of a container body 1 and a lid 2, both of which are hermetically sealed by heat sealing. The container body 1 is formed of an aluminum foil 6 having a protective layer 3 on the outer surface and an ionomer resin layer 5 on the inner surface with an adhesive layer 4 interposed therebetween. The above ionomer resin layer 5 is covered with aluminum foil 6
The means for forming the adhesive layer 4 on the aluminum foil 6 may be a method of applying an adhesive to the aluminum foil 6 to form the adhesive layer 4, and extrusion coating the molten ionomer resin thereon by a T-shaped die method. Ionomer resin film is attached to aluminum foil 6 with adhesive.
Alternatively, the aluminum foil 6 on which the ionomer resin layer 5 is formed may also be used.
The adhesive strength of the ionomer resin layer 5 to the aluminum foil 6 can also be increased by heating. In this case, as a package to be filled with contents corrosive to aluminum foil such as lactic acid, an ionomer resin film laminated to the aluminum foil 6 is preferable to the above-mentioned aluminum foil 6 coated with an ionomer resin by extrusion. It is preferable that it has better corrosion resistance. Further, as the adhesive layer 4, ethylene acrylic acid emulsion or ionomer emulsion is used. This further improves corrosion resistance. That is, when laminating the above-mentioned ionomer resin layer 5 on the aluminum foil 6, if the aluminum foil 6 and the ionomer resin film are directly adhered without providing the adhesive layer 4, the adhesive strength is insufficient. Furthermore, when a urethane-based adhesive is used, the adhesive force is insufficient. When the adhesive layer 4 is made of ethylene acrylic acid emulsion or ionomer emulsion as described above, strong adhesive force is obtained and excellent corrosion resistance is exhibited. The thickness of the ionomer resin layer 5 is 10 to 80μ
The thickness is appropriate, preferably about 20 to 60μ. This is because if the thickness is 10μ or less, pinholes are likely to occur during molding, etc., and there is a problem in terms of corrosion resistance, while if the thickness is 80μ or more, there is a problem in that the cost increases. In addition, the adhesive layer 4
The appropriate thickness is 0.1μ to 15μ, preferably
0.5~10μ is good. This is because if the thickness is less than 0.1μ, the adhesive strength is insufficient and the corrosion resistance is also inferior, whereas if the thickness is more than 15μ, there is no particular problem in terms of properties, but the cost is high and it is uneconomical. It is. The protective layer 3 formed on the outer surface of the aluminum foil 6 is an epoxy resin coat and has a thickness of about 2 to 3 microns. Next, the lid 2 is formed of an aluminum foil 10 having a protective layer 7 on the outer surface and a modified polyethylene resin layer 9 on the inner surface with an adhesive layer 8 interposed therebetween. As the modified polyethylene resin layer 9, one or more of the following resins may be blended with styrene graft modified polyethylene. Examples of this resin include ethylene vinyl acetate, saponified ethylene-vinyl acetate copolymer, carboxylated ethylene-vinyl acetate copolymer, saponified carboxylated ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ethylene-acrylic acid copolymer. Examples include ethyl acid copolymer, carboxylated polyethylene, carboxylated polypropylene, polyethylene, and polypropylene. When providing the modified polyethylene resin layer 9 on the aluminum foil 10, the following considerations are required. That is, the container body 1 and the lid 2 are tightly attached by heat sealing as described later, but if the adhesive force between the aluminum foil 10 of the lid 2 and the modified polyethylene resin layer 9 is too weak, the lid may When the container 2 is unsealed, separation occurs between the aluminum foil 10 and the modified polyethylene resin layer 9, resulting in a problem that the modified polyethylene resin film remains on the entire surface of the container. Therefore, in order to prevent this, an adhesive layer 8 is provided between the aluminum foil 10 and the modified polyethylene resin layer 9, which provides an interlayer adhesive force that is at least stronger than the heat seal strength between the container body 1 and the lid 2. is required. This adhesive layer 8
As the adhesive constituting the adhesive, ethylene acrylic acid emulsion and ionomer emulsion adhesives are suitable. The thickness of the modified polyethylene resin layer 9 is 8 to 8.
Approximately 35μ is appropriate. This is because if the thickness is less than 8μ, pinholes are likely to occur and there is a problem with corrosion resistance.
On the other hand, if the thickness is 35 μm or more, the strength of the film is too high, and when the package is opened, it cannot be opened easily, and there is a problem that the film remains in the opening. The protective layer 7 formed on the outer surface of the aluminum foil 10 of the lid 2 is a nitrocellulose or epoxy resin coat, and has a thickness of about 2 to 3 microns. The thickness of the aluminum foils 6 and 10 used for the container body 1 and lid 2 is determined by taking into consideration moldability, etc.
It may be selected appropriately within the range of 30 to 130μ. Also,
Depending on the application, it is also possible to change the aluminum foil to a biaxially stretched polyester film. The container body 1 and lid 2 configured as described above are sealed by heat-sealing the ionomer resin layer 5 inside the container body 1 and the modified polyethylene resin layer 9 inside the lid 2, and the container body 1 and lid 2 are sealed as a package. configured. Heat sealing using a combination of this ionomer resin and modified polyethylene resin allows low-temperature sealing and does not cause wrinkles in the sealed portion. That is, it has better low-temperature sealing properties than polypropylene and the like, and extremely excellent hot-tack properties compared to ethylene-vinyl acetate copolymers. Therefore, even when filling a so-called hot pack, in which the contents such as yogurt mousse are heated to 70 to 80 degrees Celsius, heat sealing using a combination of ionomer resin and modified polyethylene resin can seal the bottom seal (on the container body side). Even if the internal pressure inside the package increases by applying a sealing method that applies more heat, sufficient sealing strength can be obtained and the sealed portion will not wrinkle. The heat sheet between the container body 1 and the lid 2 is as follows:
It may be the bottom seal described above or a top seal that applies heat from the lid 1 side. In addition, in this case, if a ring seal with very high pressure is used, the modified polyethylene resin layer 9 of the lid body 2 is likely to break at the end of the heat-sealed portion, and the lid body 2
It becomes easy to open the container body 1, and the polyethylene resin layer 9 does not remain in a protruding shape inward from the opening edge of the container body 1, and the container can be opened cleanly. In this way, when heat sheeting is performed under extremely high pressure, the lid 2 can be opened even more easily if the lid material is molded. On the other hand, even when heat sealing is performed at a relatively low pressure, interfacial destruction occurs between the ionomer resin layer 5 and the modified polyethylene resin layer 9 when the package is opened. The package can be opened cleanly without leaving any modified polyethylene resin layer 9 on the first side. In the above, a case has been described in which the container body 1 is formed of an aluminum foil 6 having an ionomer resin layer 5, and the lid body 2 is formed of an aluminum foil 10 having a modified polyethylene resin layer 9. is formed of an aluminum foil 10 having a modified polyethylene resin layer 9 of 10 to 80 μm, and the lid body 2 is formed of an ionomer resin layer 5 of 8 to 35 μm.
It may also be formed from an aluminum foil 6 having a . The important thing about this idea is that the container body 1
The heat sealing layer between the lid body 2 and the lid body 2 is a combination of an ionomer resin layer 5 and a modified polyethylene resin layer 9. Therefore, as shown in FIG. 2, the accommodating portion 11 may of course be formed not only in the container body 1 but also in the lid 2. in this case,
The thickness of each resin layer, aluminum foil, etc. may be appropriately selected within the above range. As described above, the adhesive surfaces of the lid and the container body are made of a combination of an ionomer resin layer and a modified polyethylene resin layer, and the ionomer resin layer and modified polyethylene resin layer are coated with aluminum foil and coated with ethylene acrylic acid emulsion or ionomer emulsion. The technical problems of this invention, such as corrosion resistance, low-temperature sealing performance, sealing performance, and easy openability, are solved by adhering the modified polyethylene resin layer of this invention through an adhesive layer. If the polyethylene resin layer is replaced or the adhesive layer is replaced with something else, the technical problems of this invention will no longer be solved. This is clear from the following experimental examples. [Experimental Example 1] Lid A and B, which differ only in the heat sealing layer, were adhered to a container body with the layered structure shown below by heat sealing, and the peel strength, easy openability, and adhesion were evaluated. We conducted tests on The results are shown in Table 1. In addition, in Table 1, lid body A
The one with lid B is shown as a product of the present invention, and the one with lid B is shown as a comparative product. (Layer composition of container body) Epoxy coat (2μ) / 100μAl (0) / Ethylene acrylic acid emulsion coat (2μ) / Ionomer (50μ) (Layer composition of lid A) Epoxy coat (2μ) / 70μAl (0) / Ethylene acrylic acid emulsion coat (2μ) / Modified polyethylene (trade name “VMX Y-02” manufactured by Mitsubishi Yuka Co., Ltd., 30μ) (Layer structure of lid B) Epoxy coat (2μ) / 70μAl (0) /Ethylene acrylic acid emulsion coat (2μ) Bottom density polyethylene (30μ)

[Table] From the results shown in Table 1, in the case of the comparative product in which the adhesive surface between the lid and the container body is a combination of bottom-density polyethylene and ionomer, the low-temperature sealing performance is poor, and the bottom of the flange of the container body when opened. It can be seen that the density polyethylene remains in the form of a film, and the technical problem of this invention cannot be solved. [Experimental Example 2] Similarly to Experimental Example 1, lids C and D, which differ only in the heat-sealing layer, were adhered to a container body having the layer structure shown below by heat sealing, and the peeling strength was determined. , easy openability, and sealability were tested. The results are shown in Table 2. In Table 2, the lid C is shown as a product of the present invention, and the lid D is shown as a comparative product. (Layer composition of container body) Epoxy coat (2μ) / 100μAl (0) / Ionomer emulsion coat (2μ) / Ionomer (50μ) (Layer composition of lid C) Epoxy coat (2μ) / 70μAl (0) / Ionomer Emulsion coat (2μ)/modified polyethylene (product name: “VMX” manufactured by Mitsubishi Yuka Co., Ltd.)
Y-02", 30μ) (Layer structure of lid D) Epoxy coat (2μ) / 70μAl (0) / Ionomer emulsion coat (2μ) / Bottom density polyethylene (30μ)

[Experiment example 3]

A laminate was prepared in which a 50μ ionomer resin layer was attached to a 100μ aluminum foil via a urethane adhesive layer, and the peel strength between the aluminum foil and the ionomer resin layer was measured, and it was found to be 150g/
It was found that it was 15 mm wide, and was so strong that it would cause hollowing during molding, making it impossible to put it to practical use. [Effects of the invention] As described above, this invention has the effect of providing a package made of aluminum foil that has excellent corrosion resistance, low-temperature sealing performance, sealing performance, and easy-opening performance.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a container body and a lid of a package according to this invention, and FIG. 2 is a sectional view showing another embodiment. 1... Container body, 2... Lid, 3, 7... Protective layer, 4, 8... Adhesive layer, 6, 10... Aluminum foil, 5... Ionomer resin layer, 9... Modified polyethylene resin layer.

Claims (1)

[Scope of utility model registration request] The lid or container body is formed of aluminum foil, which has a protective layer on the outer surface and an ionomer resin layer on the inner surface via an adhesive layer of ethylene acrylic acid emulsion or ionomer emulsion, and the protective layer is provided on the outer surface. The container body or lid is formed of aluminum foil having a styrene graft modified polyethylene resin layer on the inner surface via an adhesive layer of ethylene acrylic acid emulsion or ionomer emulsion, A package that is sealed with a modified polyethylene resin layer by heat sealing.