JPH07100509B2 - Freestanding bag - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a self-standing bag that stores 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, even if the packaging form as described above is put into the microwave oven as it is, the contents cannot be heated,
In addition, the microwave oven itself may be damaged, so 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 risk that the contents will be omitted.

Therefore, 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. 60-2880).
No. 85).

However, in such a self-supporting bag, a bottom sheet is inserted in the bottom part in order to make the bottom part expandable. For example, when performing retort sterilization treatment, moisture penetrates from the overlapping part of the bottom sheet, There is a drawback of staying in the mating part.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a self-standing bag in which the overlapping portion of the bottom sheet is also sealed and which 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. The layers are laminated, and the inner surface of the side sheet that allows the portion of the metal thin film layer to be peeled from the base material by hand is overlapped,
A two-fold inner bottom sheet having a resin layer whose outer surface is heat-sealable and has weak adhesive strength at both ends of the inner surface, and notches provided at both ends, the lower edge of which is above the lower end of the side sheet. Insert it in the stacked side sheets so that it is located at
Furthermore, the outer bottom sheet of the two folds, the outer surface of which is heat-fusible and which includes a metal thin film layer and has notches at both ends, is inserted so as to overlap the outer side of the inner bottom sheet, and the notches of both are aligned, and The lower edge of the outer bottom sheet is substantially aligned with the lower edge of the side sheet, the side edges of the side sheet are heat-sealed, and the side edges and the lower edge of the inner bottom sheet and the inner surface of the side sheet are heat-sealed, The outer bottom sheet, the lower edge portion, and the inner surface of the side sheet were heat-sealed to form a self-standing bag.

[Action]

Since the bag formed of the above-mentioned sheet is hermetically sealed all around, it does not allow the ingress of moisture and the like, and the gas barrier layer including the metal thin film layer is made of a synthetic resin base material via a resin layer having a weak adhesive strength. Since it is laminated with, it can be easily peeled off by hand, and the outer bottom sheet can also be easily removed by cutting off the lower end of this bag. When these are removed, a bag made of synthetic resin base material However, since it does not reflect microwaves, it can be cooked in the microwave as it is.

〔Example〕

First, the side sheet, the inner bottom sheet, and the outer bottom sheet that form the self-standing bag will be described.

As shown in FIG. 1, the side sheet 1 is made of a synthetic resin base material 2.
A heat-sealing layer 3 is laminated on the inner surface, and a metal thin film layer 6 such as a metal foil or a metal vapor deposition film is laminated as a gas barrier layer through a resin layer 4 and an adhesive layer 5 having relatively weak adhesive strength on the outer surface. Is. 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 or laminating a synthetic resin film. In addition, a printed layer may be provided on the outer surface of the metal thin film layer 6.

The base material 2 includes polyester, nylon (trade name),
Polypropylene or the like is preferable, and either a simple substance or a composite thereof may be used. Further, as the heat-sealing layer 3, polyolefin, ethylene-vinyl acetate copolymer, or the like is 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 vinyl resin, acrylic resin, polyamide resin, silicone resin, etc., which has a relatively weak adhesive strength, and is formed by a part coat of this 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 notch or perforation penetrating the base material 2 and the layer 3, the function of which will be described later.

Next, as shown in FIG. 4 and FIG. 5, the inner bottom sheet 10 is provided with the heat-sealing layer 12 on the outer surface of the synthetic resin substrate 11 and the resin layers 14 having weak adhesive force on both ends of the inner surface. It is a thing. The base material 11 is made of a simple substance or a composite of polyester, nylon, polypropylene, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, or the like. Also, layer 12
Is selected from polyolefins, ethylene-vinyl acetate copolymers, and the like, which have good heat fusion properties with the heat fusion layer 3 of the side sheet 1. If the base material 11 has thermal adhesiveness, this layer
12 may be omitted.

Further, the layer 14 is selected from a resin that can be heat-sealed with the layer 22 described below at a relatively low temperature and can be easily peeled off by hand.

As shown in FIG. 6, the outer bottom sheet 20 is formed by providing a heat-sealing layer 22 on a metal thin film layer 21 such as a metal foil or a metal vapor deposition film. It is preferable to provide the protective layer 23 on the outer surface of the layer 21. Further, the heat-sealing layer 22 may be any material that can be heat-sealed to the heat-sealing layer 3 of the side sheet, and polyolefin, ethylene-vinyl acetate copolymer or the like is used.

FIGS. 7 and 8 show an example of forming a self-standing bag using the side sheet 1, the inner bottom sheet 10 and the outer bottom sheet 20 as described above.

First, two side sheets 1 and the heat-sealing layer 3 as the inner surface,
The inner bottom sheet 10 and the heat-sealing layer 22
To the outside and fold in half and insert. Sheet 10
Notches 13 are formed in advance at both ends of the. Further, the lower edge of the sheet 10 is located above the lower edge of the sheet 1. Further, the outer bottom sheet 20 is also folded in two with the heat-sealing layer 22 as the outer surface. Notches 24 are formed at both ends thereof. The cutout 24 is provided at a position corresponding to the cutout 13 of the inner sheet 10. The sheet 20 is inserted into the lower side of the sheet 10, and the lower edge of the sheet 20 extends below the lower edge of the sheet 10 so as to be substantially aligned with the lower edge of the side 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. 8, whereby a bag is completed. At this time, in the bottom sheet 10, 20, both side edge portions of the inner bottom sheet 10 and the inner surface of the side sheet 1, and both inner surface end portions of the sheet 10 and the outer surface of the sheet 10 are fused together. At 24 points, the inner surfaces of the side sheets 1 and 1 on both sides are directly fused to each other. Furthermore, the lower edge outer surface of the inner bottom sheet 10 and the lower edge outer surface of the outer bottom sheet 20 are fused to the inner surface of the side sheet 1.

The contents are stored in such a bag, and as shown in FIG.
When the opening 9'is heat-sealed, the package is completed.

As shown in FIG. 8, half-cuts 31 and 32 may be preliminarily provided at the lower corners of such a bag or slightly above it. This half-cut is a cut that reaches at least the base material 2 of the sheet 1 and is the metal thin film layer 6 of the bag.
Is a clue to peeling. 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. .

In order to remove the metal thin film layer 6 from both sides of the bag, one half cut 31, 32 is provided on the opposite side of the bag.

In order to use this bag for cooking, first, the corner portion of the bag is bent along the half cut 31 shown in FIG. 8, and the base material 2 of the metal thin film layer 6 is 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 protection layer 7 using that as a clue,
It is peeled 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 base material 2 remains as shown in FIG. Then, when the lower part of the heat sealing portion 9 is cut along the arrow 33 in FIG. 9, the outer bottom sheet 20 is fused to the side sheet 1 only at its lower edge portion, and the fused portion is Since the outer bottom sheet 20 is cut off from the side sheet 1, and the outer bottom sheet 20 is adhered to the inner bottom sheet 10 and both ends thereof via the resin layer 14 having a weak adhesive force, It can be easily peeled off by hand, and a self-supporting synthetic resin bag as shown in Fig. 10 is formed. Put this bag in the microwave and cook. At this time, since the cut A is provided at the upper end of the self-standing 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 the lower part of the heat-sealing part 9 (the part corresponding to the arrow 33 in FIG. 9), bending at the half cut 32, the same as above. Alternatively, the metal thin film layer 6 may be peeled off.

〔effect〕

As described above, the self-supporting bag of the present invention is completely sealed at the entire peripheral edge thereof, so that it is possible to prevent the infiltration of water and the like, and is composed of a laminated body of a synthetic resin base material and a metal thin film layer. Therefore, it is tough and has excellent barrier properties, can withstand normal temperature distribution, long-term storage, etc., can prevent alteration of the contents, and can peel the metal thin film layer to make it self-supporting. Therefore, it is possible to cook in a microwave oven, and if a cut is provided in advance, it is possible to prevent the bag from bursting due to an increase in internal pressure during cooking.

That is, since the self-supporting bag of the present invention can be used consistently from distribution, storage, and cooking, it is very convenient and easy to handle, and at the same time, it 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.
Figure is a cross-sectional view of the inner bottom sheet, Figure 5 is a plan view of the same,
FIG. 6 is a cross-sectional view of the outer bottom sheet, FIG. 7 is an exploded perspective view of the self-standing bag, FIG. 8 is a completed plan view of the same as above, and FIG. 9 is a plan view showing a state in which the gas barrier layer of the same is peeled off, FIG. 10 is a perspective view of a synthetic resin bag with the lower end portion of the same bag cut off. 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 ...... Inner bottom sheet, 11 …… Synthetic resin base material,
12 ... Heat fusion layer, 13 ... Notch, 14 ... Resin layer, 20 ... Outer bottom sheet, 21 ... Metal thin film layer, 22 ... Heat fusion layer, 24
...... Notch.

 ─────────────────────────────────────────────────── ─── 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 inner surfaces of the side sheets that can be manually peeled off from the synthetic resin base material are overlapped, and the outer surface is heat-sealable and has a resin layer with weak adhesive force at both ends of the inner surface, and notches at both ends. The two-folded inner bottom sheet is inserted into the superposed side sheets such that the lower edge of the folded inner bottom sheet is located above the lower edge of the side sheet, and the outer surface of the sheet can be heat-sealed to form a metal thin film. A two-fold outer bottom sheet having a cutout at both ends including a layer is inserted into the outside of the inner bottom sheet so that the two notches are aligned and the lower edge of the outer bottom sheet is the lower edge of the side sheet. Match, heat seal the side edges of the side sheet, Side edges of the sheet and lower portion and the inner face of the side face sheet heat sealing, self-standing bag the lower edge portion and the inner surface of the side sheets of the outer bottom sheet was heat sealed.