JPH0818621B2 - Independent bag - Google Patents

Description

Description: [Industrial field of application] The present invention relates to a self-supporting bag that can store food and the like and can be cooked in a microwave oven.

[Conventional technology and its problems]

In recent years, the number of cooked or semi-cooked foods that can be served on the table by simply reheating them in a microwave oven or the like is increasing. In order to prevent deterioration of the taste and quality of such foods, light and air, Sealing and packaging are generally performed with a packaging material including a metal thin film layer such as an aluminum foil having an excellent barrier property against moisture.

However, since the metal thin film layer reflects microwaves, the contents cannot be heated even if the packaging form as described above is put into the microwave oven as it is, and the failure of the electron lens itself. Since it also causes the above, the package is opened, the contents are taken out, transferred to another container, and heated. However, even in that case, it is necessary to further wrap the container with a wrap film, which is very troublesome.

Therefore, in order to save the labor as described above, the present inventors have already proposed a packaging bag in which the metal thin film layer portion can be removed and thus can be cooked as it is.

However, in such a bag, there is a risk that the internal pressure of the bag will rise and burst due to overheating during cooking. To prevent this, it is necessary to provide an opening in the bag, but a flat bag cannot stand by itself. Therefore, there is a possibility that the contents will be omitted.

Therefore, although the present inventors have proposed a self-supporting bag in which the contents do not spill even if an opening is provided (Japanese Patent Application No. 60-288084), it is a bottom surface for expanding the bottom surface because of its structure. A sheet is required, and for example, when retort sterilization is performed, there is a risk of water permeating from the joint of the bottom sheet.

An object of the present invention is to provide a packaging bag which is normally a flat bag but which is self-supporting when used and can withstand retort sterilization.

[Means for achieving the purpose]

In order to achieve the above object, in the present invention, a gas barrier including a metal thin film layer on the outer surface of a synthetic resin substrate whose inner surface can be heat-sealed with an adhesive layer and a resin layer having a weaker adhesive strength than the adhesive layer. Layers were laminated, and the inner surface of the side sheet which was capable of peeling the metal thin film layer portion from the base material by hand was overlapped, and the outer surface was heat-sealable, and the adhesive layers were provided on the inner surfaces of both ends.
The folded synthetic resin bottom sheet is inserted into the superposed side sheets so that the lower edge thereof is located above the lower end of the side sheet, and the side edges and the lower edge of the side sheet are heat-sealed, and Heat sealing the side edge and the lower edge of the bottom sheet and the inner surface of the side sheet, and a portion corresponding to above the lower edge of the side sheet and below the heat sealed lower edge of the bottom sheet. It was possible to become independent by cutting the sideways.

[Action]

The bag formed of the above-mentioned sheet has a perfect sealing property because all the peripheral edges are fused, and the gas barrier layer including the metal thin film layer is laminated with the base material through the resin layer having low adhesive strength. Therefore, it can be easily peeled off by hand, and when it is removed, a bag made of a synthetic resin base remains, and since it does not reflect microwaves, it can be cooked as it is in a microwave oven. Further, by cutting off the lower end portion of this bag, the lower edge of the bottom sheet becomes free, the bottom surface can be expanded, and it becomes possible to stand by itself.

〔Example〕

First, the structures of the side sheet and the bottom sheet forming the packaging bag will be described.

As shown in FIG. 1, the side sheet 1 has a gas barrier through a heat-sealing layer 3 on the inner surface of a synthetic resin substrate 2, and a resin layer 4 and an adhesive layer 5 having relatively weak adhesive strength on the outer surface. A metal thin film layer 6 such as a metal foil or a metal vapor deposition film as a layer is laminated. A surface protective layer 7 is preferably provided on the outer surface of the metal thin film layer 6. The layer 7 is formed by coating a synthetic resin with a synthetic resin film or the like. In addition, a printed layer may be provided on the outer surface of the metal thin film layer 6.

Polyester, nylon (trade name), polypropylene and the like are suitable for the base material 2, and may be a simple substance or a composite thereof. In addition, the heat fusion layer 3
As such, polyolefin, ethylene-vinyl acetate copolymer and the like are used. The layer 3 can be omitted if the base material 2 itself has a heat fusion property.

The resin layer 4 is composed of a single resin or a mixture of a vinyl resin, an acrylic resin, a polyamide resin, a silicone resin or the like, which has a relatively low adhesive strength, and is formed by a part coat of the resin. In one example, as shown in FIGS. 3A, 3B, and 3C, the uncoated portion forms a dot-shaped, linear-shaped, or grid-shaped pattern. The resin layer 4 may be provided on the metal thin film layer 6 contrary to FIG. In some cases, it can be applied over the entire surface.

As shown in FIG. 2, a reinforcing layer 6 ′ can be provided on the inner surface of the metal thin film layer 6. The reinforcing layer 6'is made of polyester, polypropylene, nylon, epoxy resin or the like, and prevents corrosion of the metal thin film layer during retort treatment and at the same time increases the thickness as a gas barrier layer and facilitates peeling. Also useful for. In the figure,
A is a cut line that penetrates the base material 2 and the layer 3. Its function will be described later.

Next, as shown in FIG. 4 and FIG. 5, the bottom sheet 10 comprises a synthetic resin substrate 11 provided with a heat-sealing layer 12 on the outer surface and adhesive layers 14 on the inner surfaces of both ends. The base material 11 is made of a single material or a composite material such as polyester, nylon and polypropylene. The layer 12 is selected from polyolefin, ethylene-vinyl acetate copolymer, and the like, which has a good heat fusion property with the heat fusion layer 3 of the side sheet 1. The base material 11
This layer 12 may be omitted if it has a heat fusion property. Further, the adhesive layer 14 may be made of any resin as long as it can be adhered at a relatively low temperature. The notch 13 is preferably formed when the adhesive strength of the adhesive layer 14 is weak.

FIG. 6 shows the side sheet 1 and the bottom sheet as described above.
An example of the packaging bag formed using 10 is shown.

First, the two side sheets 1 and the heat-sealing layer 3 are placed on the inner surface, and the bottom sheet 10 and the heat-sealing layer 12 are stacked therebetween.
To the outside and fold in half and insert. At this time, the lower edge of the sheet 10 is located above the lower edge of the sheet 1. Then, the peripheral portion of the sheet 1 and the portion corresponding to the lower edge of the sheet 10 are heat-sealed to form the heat-sealing portions 8 and 9 as shown by a chain line in FIG. 7, whereby a bag is completed.

The method of forming the bag is not limited to the above. For example, sheet 1
Is folded in two with the heat-sealing layer 3 as the inner surface, and the peripheral portion and the portion corresponding to the lower edge of the sheet 10 are heat-sealed in the same manner as described above to form the heat-sealing portions 8 and 9. Good.

As shown in FIG. 7 and FIG. 8, half cuts 21 and 22 are provided at the lower end corners of such a bag or slightly above. This half cut is a cut reaching at least the base material 2 and serves as a clue for peeling the metal thin film layer 6 of the bag. That is, when the metal thin film layer 6 and the substrate 2 are slightly separated at the end face of the cut when bent so as to expand along the cut, the metal thin film layer 6 can be peeled off by pinching the portion. .

Further, in order to remove the metal thin film layer 6 from both surfaces of the bag, one half cut 21, 21 is provided on the opposite surface of the bag.

In order to use this bag for cooking, first, the corner portion of the bag is bent along the half cut 21 shown in FIG. 7, and the metal thin film layer 6 and the base material 2 are separated at the end face of the cut. The metal thin film layer 6 can be pinched by hand. When the metal thin film layer 6 is pulled together with the surface protective layer 7 by using this as a clue, the metal thin film layer 6 is separated from the base material 2. Similarly, when the metal thin film layer 6 is peeled off on the opposite surface of the bag, the bag made of the synthetic resin substrate 2 remains as shown in FIG. Then, as shown by the arrow in FIG. 9, when the heat sealing part 9 is cut slightly below, the lower edge of the bottom sheet 10 becomes free and can be expanded.
That is, a self-sustaining bag is obtained (Fig. 10). Put this bag in the microwave and cook. At this time, since the through cut A is provided at the upper end of the bag, the bag does not burst even if the contents expand due to heating.

When the reinforcing layer 6'is provided, it may be peeled by the above procedure together with the metal thin film layer 6.

Contrary to the above, before peeling off the metal thin film layer 6, after cutting a little below the heat-sealing part 9 (the part corresponding to the arrow in FIG. 9), the half cut 22 is bent and the same as above. Alternatively, the metal thin film layer 6 may be peeled off.

〔effect〕

As described above, since the packaging bag of the present invention is composed of the laminated body of the synthetic resin base material and the metal thin film layer, it is tough and has excellent barrier properties, and can withstand handling such as ordinary temperature distribution and long-term storage. In addition, it is possible to prevent alteration of the contents, and since the peripheral portion of the bag including the end portion of the bottom sheet is completely sealed, it is possible to prevent the infiltration of water due to retort sterilization or the like. In addition, the metal thin film layer can be peeled off, and after peeling it can be self-supporting, so it can be cooked in a microwave oven, and if a cut is provided in advance, the bag is prevented from bursting due to an increase in internal pressure during cooking. be able to.

That is, since the packaging bag of the present invention can be used consistently throughout distribution, storage, and cooking, it is very convenient to handle and saves labor, and at the same time, has an effect of saving resources.

[Brief description of drawings]

1 and 2 are sectional views of the side sheet of the self-standing bag, FIG.
FIG. 4 is a plan view showing the pattern of the intermittent resin layer of the same as above.
The figure shows a sectional view of the bottom sheet, a plan view of the same as FIG. 5, and a sixth view.
Figure is an exploded perspective view of the packaging bag, Figure 7 is a completed plan view of the same,
FIG. 8 is a partially enlarged side view of the same as above, FIG. 9 is a plan view of the bag from which the metal thin film layer is peeled off, and FIG. 1 ... Side sheet, 2 ... Synthetic resin base material, 3 ... Heat fusion layer, 4 ... Resin layer, 5 ... Adhesive layer, 6 ... Metal thin film layer, 6 '... Reinforcing layer, 7 ...... Surface protection layer, 8, 9 ...... Heat seal part, 10 ...... Bottom sheet, 11 ...... Synthetic resin base material, 12 ・ ・ ・
… Heat fusion layer, 13 …… notch, 14 …… adhesive layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Nakano 1-25 Toyo Aluminum Co., Ltd., 4-25, Minamikyutaro-cho, Higashi-ku, Osaka-shi, Osaka

Claims (1)

[Claims] 1. A gas barrier layer including a metal thin film layer is laminated on an outer surface of a synthetic resin substrate whose inner surface is heat-sealable, with an adhesive layer and a resin layer having a weaker adhesive strength than the adhesive layer, and this gas barrier. The bottom surface of the two-folded bottom sheet, in which the inner surfaces of the side sheets that can be manually peeled off from the synthetic resin base material are overlapped and the outer surfaces are heat-sealable and the adhesive layers are provided on the inner surfaces of both ends, The side sheet is inserted into the overlapped side sheet so as to be located above the lower end of the side sheet, the side edges and the bottom edge of the side sheet are heat-sealed, and the side edge and the bottom edge of the bottom sheet and the side surface. A bag having self-sustainability that can be self-supported by heat-sealing the inner surface of the sheet and laterally cutting a portion corresponding to a lower side of the bottom sheet and a lower side of the bottom sheet above the lower edge of the side sheet. .