JPH1017030A - Packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a packaging bag which is suited to cooking by heating in a microwave oven. SOLUTION: A bag body is formed of a film 1a which is easy of tearing in one fixed direction. Inside this bag body and in the direction in which the synthetic resin film 1a, being a component of the bag body, is to be torn there is provided a gas-permeable film 2 which consists of a strip of a film with a multiplicity of small perforations 2c and is heat-adhesive on the two sides and one side of which forms an easy-to-peel side 2a with the heat-bonding strength relatively lower than the other side. Each of the two ends of the gas- permeable film 2 is put between the films 1a, 1b at a heat-sealable marginal part of the bag body and sealed together under heat. Either the whole of or a marginal part of the easy-to-peel side 2a of the gas-permeable film 2 and the synthetic resin film la forming one side of the bag body 1 are sealed together under heat. A tab 5 is formed in the synthetic resin film 1a forming one side of the bag body and at a position corresponding to one end of the gas-permeable film 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be used for packaging various foods, deodorants, fragrances, desiccants, decarbonizing agents, various repellents, etc., especially for foods cooked in a microwave oven. Regarding packaging bags suitably used for packaging,
In more detail, while always satisfying the characteristics required for food packaging bags such as good heat resistance, gas barrier properties, seal strength, etc., when foods are cooked in a microwave oven together with the packaging bags, The present invention relates to a packaging bag capable of satisfactorily discharging steam generated during cooking.

[0002]

2. Description of the Related Art Conventionally, packaging containers have a sales promotion effect by a display,
It has been proposed and implemented to add various functions in consideration of protection, preservation, convenience in use, and the like of contents. For example, in the case of a food container, for example, a material obtained by compounding (laminating) various synthetic resin films, paper, aluminum, etc., as a material for forming the packaging container, in order to impart the required functions to the above-described packaging container. Of course, these materials are printed for display and finally processed into pouches, trays, tubes, bottles, boxes, etc., in which various foods are stored. It is distributed and sold.

[0003] In recent years, the social environment surrounding food has rapidly changed due to changes in sales styles represented by convenience stores, an increase in singles and elderly people, rationalization of distribution, and changes in cooking methods using microwave ovens and the like. Accordingly, consumer demands for the above-mentioned convenience, safety, taste, and the like have been changing in various ways, and accordingly, functions expected or required of packaging containers have become wide and sophisticated. .

[0004] On the other hand, there are various methods for preserving food, such as boil processing, retort sterilization, frozen storage, vacuum packaging, inert gas replacement packaging, and aseptic packaging. Appropriate methods suitable for suitability, distribution, storage period, etc. are adopted. In this case, it is natural that the packaging container must have good suitability and resistance to these preservation processing methods to be adopted, but the convenience and the cooking method required by consumers are also not considered. It is necessary to take this into consideration. For example, in view of the convenience and safety of heating and cooking in a microwave oven, there is no current packaging container having a function that is sufficiently satisfactory.

[0005] To explain this point in detail, for example, a typical process of recent food processing, distribution and cooking is food processing → vacuum packaging → sterilization of boil (steam) → freezing and distribution preservation → microwave cooking. However, the basic functions required of the packaging container at this time are the resistance in the above-mentioned steps, and the safety and convenience in the above-mentioned steps. As a packaging container for food that goes through such a process, a packaging bag formed in a bag shape is generally used. In this case, the material includes a gas barrier property capable of maintaining a vacuum, and sterilization during boil (steam) sterilization. It needs heat and water resistance to boil (steam) and low temperature resistance (strength, pinhole, etc.) during frozen storage and storage, and gas barrier properties, heat and water resistance,
In addition to providing low-temperature resistance, a strong sealing strength against steam pressure is required. On the other hand, at the time of heating and cooking with a microwave oven in the above process, the contents can be easily opened and the contents can be easily taken out, and the convenience that the package can be put into the microwave oven and cooked as it is can be obtained. Required.

In this case, it is not possible to simply open the packaging bag, put it in a microwave oven, and cook it by heating. In other words, this kind of food contains a lot of liquid components such as water and oil, and depending on the amount, these liquid components may leak. It is necessary to transfer to an appropriate container. In addition, a self-supporting packaging bag has been proposed. According to this self-standing bag (standing pouch), it is possible to open the upper part of the bag and place it in a microwave oven for cooking, Due to the risk of falling due to heat and steam generated at the time and the possibility of falling when rotated by a turntable provided in a microwave oven, the self-sustained stability is not reliable. In such a case, the liquid generated from the oily food becomes extremely hot, and the outflow due to falling is dangerous, and such a method cannot be adopted.

[0007] On the other hand, there are various proposals for packaging bags suitable for heating by microwave oven. However, in a state where food is contained in a package, the above-mentioned vacuum packaging → sterilization of boil (steam) → frozen distribution storage. → It is no exaggeration to say that there is nothing that can be favorably provided to a series of steps of cooking in a microwave oven.

[0008] For example, as a packaging bag suitable for cooking by heating in a microwave oven, a packaging bag formed by laminating a film material having a thermal adhesive property and heat sealing the peripheral portion thereof to form a bag (1) One having a structure in which the sealing strength of a part of the seal part is weakened, and this part is ruptured by the vapor pressure at the time of heating by a microwave oven to form an opening part. There is a proposal of a structure having a structure in which an internal liquid does not flow out of the unsealed portion in an unpressurized state by utilizing the adhesion of a film which is not laminated and forming a portion. In the packaging bags of 1) and (2), a complete opening is formed at the time of cooking by heating in a microwave oven, and the vapor pressure in the packaging bag can be effectively reduced, but at the same time, the liquid inside flows out. Than it is. Therefore, these packaging bags need to be in the form of a self-standing bag (standing pouch), but as described above, sufficient safety cannot be ensured in this form. Further, the packaging bag of the above (2) in which the unsealed portion was formed could not exhibit the function required in the process of the vacuum packaging → boil (steam) sterilization at all, and partially reduced the sealing strength. In the packaging bag of (1), an opening is formed in the boil (steam) sterilization step in the same manner as when cooking by heating with a microwave oven, and thus the packaging bag cannot be sterilized.

[0009] As described above, at present, there is almost no packaging bag that can be favorably used in the above-described series of processes of vacuum packaging → sterilization of boil (steam) → storage in a frozen state → cooking in a microwave oven. Development of such a packaging bag is desired.

The present invention has been made in view of the above circumstances, and fully satisfies various properties required for food packaging bags such as good heat resistance, gas barrier properties, and seal strength at all times.
Vacuum packaging → Boil (steam) sterilization → Freezing, distribution and preservation can be performed well. In addition, when cooking food stored inside with a microwave oven, the steam generated at the time of cooking is good. Another object of the present invention is to provide a packaging bag that can be safely discharged.

[0011]

According to the present invention, in order to achieve the above object, a plurality of thermo-adhesive synthetic resin films are superimposed, or a single thermo-adhesive synthetic resin film is folded back and superimposed, and a peripheral edge thereof is formed. A packaging bag formed in a bag shape by heat-sealing the part, the bag body is formed using a film having a tear cut property in a certain direction as the above-mentioned heat-adhesive synthetic resin film, and one side is on the other side. A gas permeable film in which a number of small holes are perforated in a double-sided heat-adhesive band-like film that is an easy peel surface having a lower heat-adhesive strength, the synthetic resin film constituting the bag body in the bag body. It is arranged along the tear-cut direction, and both ends are sandwiched between the films by the heat-sealing portion of the peripheral portion of the bag body to be integrally heat-sealed. -The entire surface or the periphery of the peel surface is heat-sealed to the synthetic resin film forming one surface of the bag body, and the position corresponding to the end of the gas permeable film of the synthetic resin film forming one surface of the bag body. The present invention provides a packaging bag characterized in that a tab portion is formed on the packaging bag.

[0012] The packaging bag of the present invention can reliably remove steam generated during cooking by heating in a microwave oven without deteriorating various properties required as a packaging bag for food packaging, such as various resistances, gas barrier properties, and seal strength. And it has a function that can be safely discharged, that is, it can always maintain a completely sealed state at all times, and it can easily and safely form an opening during heating cooking with a microwave oven. It is a solution to a conflicting problem.

That is, the packaging bag of the present invention is obtained by laminating a plurality of thermo-adhesive synthetic resin films or by folding and laminating one thermo-adhesive synthetic resin film, and heat-sealing the periphery thereof. It is a packaging bag formed in a shape and can achieve perfect sealing properties. By selecting the film material appropriately according to the contents, sterilization and preservation method, good heat resistance, gas barrier properties, sealing Strength and the like can be reliably obtained. When the food contained in the packaging bag is to be cooked in a microwave oven together with the packaging bag, an opening is provided in the film constituting the packaging bag by pinching the tab portion and tearing one surface of the packaging bag. Good heat cooking is performed by releasing the vapor pressure generated in the packaging bag through the opening to the outside.

In this case, in the packaging bag of the present invention, when the tab portion is picked and a part of the film is torn, the film has a tear-cutting property in a certain direction. A predetermined location is securely opened at a predetermined width along with the tab portion, and the tab portion is provided at a position corresponding to an end portion of the band-shaped gas permeable film disposed in the packaging bag. The gas-permeable film is disposed along the tear-cut direction of the film forming the bag body, and the entire surface or the periphery of the easy peel surface is thermally bonded to the film on the side to be torn, so that the gas-permeable film is torn. The film piece is easily peeled off from the gas permeable film to form the opening along the gas permeable film, and the formed opening is formed by the gas permeable film. The fort is peeling state. And
The vapor pressure generated during heating and cooking is discharged to the outside through a number of small holes formed in the gas permeable film. In addition, by appropriately setting the size of the small holes formed in the gas permeable film, the gas pressure is reduced. It is possible to prevent the liquid from flowing out of the packaging bag by the conductive film, and it is possible to carry out the heating cooking satisfactorily and safely.

Here, the small holes formed in the gas permeable film are usually round holes. In the present invention, the small holes are formed as small slits formed in a cut line shape. You can also. When the small holes are formed as such small slits, when the entire surface of the easy peel surface of the gas permeable film is thermally bonded to the film forming the bag body, both edges of the slit are adhered to each other and closed. However, in this case, the slits are opened so that the slits can be opened by increasing the internal pressure of the packaging bag due to the vapor pressure generated during heating and cooking, and the vapor pressure is reliably discharged to the outside of the packaging bag through this slit. can do.

Further, in the packaging bag of the present invention, when the opening is formed by pinching the tab portion and tearing the film, the heat seal portion on the peripheral portion of the film is torn off.
In this case, the heat-sealed portion to be peeled off for forming the opening is a portion that is heat-sealed with the gas-permeable film interposed therebetween. In this case, the gas-permeable film is relatively heat-adhesive on one side. With a low easy peel surface,
Since the other side has good thermal adhesiveness, the torn film piece heat-sealed on the easy peel side can be easily peeled off from the gas permeable film, so-called easy peel function. As a result, the convenience of heating and cooking is excellent, and the other film forming the bag body (the film on the side that is not torn) is heat-sealed with the other surface of the gas-permeable film having good thermal adhesiveness. Since the gas permeable film is not separated from the other film together with the torn film piece when forming the tear opening, the formed opening is formed by the gas permeable film. It can be reliably closed. In addition, since the easy-peeling surface of the gas-permeable film obtains the easy-peeling property, the other surface of the gas-permeable film is heat-sealed to the other film constituting the bag body with good adhesive strength. Thus, excellent sealing performance can be reliably obtained without impairing the convenience by the easy peel function.

As described above, according to the packaging bag of the present invention, a completely sealed state can be maintained at all times, and various characteristics required for a food packaging bag such as good heat resistance, gas barrier properties, and seal strength. Vacuum packaging → boil (steam)
In addition to being able to satisfactorily contribute to the process of sterilization → frozen distribution and storage, when cooking the food contained inside in a microwave oven together with the packaging bag, it is possible to discharge the steam generated during heating and cooking properly and safely. You can do it.

The packaging bag of the present invention is suitably used for food packaging, particularly for food packaging intended for cooking by heating in a microwave oven, as described above. The fragrance, desiccant, oxygen scavenger, repellent, etc. are required to be kept sealed at all times, and are preferably used for applications requiring gas permeability during use.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to the drawings. 1 to 6 show a packaging bag a according to one embodiment of the present invention. This packaging bag a is composed of two synthetic resin films 1 cut into a rectangular shape.
a and 1b are overlapped with each other, and a band-shaped gas permeable film 2 is arranged along the width direction inside a bag body 1 formed by heat sealing the peripheral portion thereof to form a bag.
In the drawings, the portions that have been heat-sealed are shaded.

As the synthetic resin films 1a and 1b, those having thermal adhesiveness and good heat sealing and having gas barrier properties are used. The synthetic resin films 1a and 1b may be appropriately used depending on the contents, sterilization treatment, distribution storage method and the like. Selected. In this case, at least one of the films 1a has a tear-cutting property in a certain direction, and is used in this embodiment such that the tear-cut direction matches the width direction of the bag body 1 (FIG. 1). , 2, 5).

Such synthetic resin films 1a, 1b
As, although not particularly limited, to a film having a tear cut property in a certain direction such as a uniaxially stretched polyester film, a nylon film, a polypropylene film, a polyethylene film, a polypropylene film, an ethylene-vinyl alcohol copolymer A laminated film obtained by laminating a heat-adhesive film such as a film can be suitably used. In this case, a nylon film, an aluminum foil, ethylene-vinyl alcohol copolymer is provided between the film having the tear-cutting property and the heat-adhesive film. A laminate film of three or more layers may be formed with a united film or the like interposed therebetween. The film 1b forming the back side of the packaging bag a does not necessarily need to use a film having a tear-cutting property in a certain direction, but in order to obtain good heat sealing properties with the film 1a forming the front side,
A film having the same thermal adhesive layer as the film 1a is preferably used.

Next, the gas permeable film 2 is provided with a large number of small holes 2c in a double-sided heat-adhesive strip-shaped film having an easy-peel surface 2a having a lower heat-adhesive strength on one side than the other side 2b. As described above, the film 1a is arranged in a band along the width direction, that is, along the tear cut direction of the film 1a. In this case, both ends of the gas permeable film 2 are heat-sealed integrally in a state of being sandwiched between the two films 1a and 1b by a heat seal portion on a peripheral portion of the bag body 1 and the gas permeable film 2 The easy peel surface 2a of the conductive film 2 is entirely heat-sealed to the inner surface of the film 1a forming the front side of the bag body 1.

The gas permeable film 2 has an easy-peel surface 2a on one side which is relatively low in thermal adhesiveness, and a double-sided thermal adhesive synthetic resin film having good thermal adhesiveness on the other side 2b. It is not particularly limited as long as it has a large number of small holes formed therein, but usually, a film having relatively low thermal adhesiveness and a film having good thermal adhesiveness are laminated to form A laminated film having an easy-peel surface 2a on the film side having low adhesiveness and the other surface 2b on the film side having good thermal adhesiveness is used. Film 2 can be used.

The relatively low heat-adhesive film forming the easy peel surface 2a is a polymer alloy film of polypropylene and polystyrene, a co-extruded polypropylene film having a cohesive failure layer on the surface, ethylene / vinyl acetate Copolymer films and the like are exemplified, and as the film having good thermal adhesiveness forming the other surface 2b, a polyethylene film, a polypropylene film, an ethylene / vinyl alcohol copolymer film and the like are exemplified. In this case, if necessary, a polyester film, a nylon film, a polypropylene film, a cellophane film, an ethylene / vinyl alcohol copolymer film between the film having a relatively low thermal adhesiveness and the film having a good thermal adhesiveness. It is also possible to form a film having three layers or four or more layers sandwiching the above. Although not particularly limited, as a film having good thermal adhesiveness forming the other surface 2b side, considering the adhesiveness with the film 1b forming the bag body 1, the film 1b is It is preferable to use the same material as the heat bonding layer.

The small holes 2c formed in the gas permeable film 2 are usually round holes. In this case, the diameter of the holes is not particularly limited, but is 50 to 200.
The thickness is preferably 0 μm, particularly preferably 100 to 300 μm, whereby the vapor can be satisfactorily discharged to the outside of the bag body 1, and the liquid component generated from the contents flows out of the bag body 1 through the small holes 2 c. This can be reliably prevented. On the other hand, although not specifically shown, the small hole 2c may be formed as a small slit having a cut line shape. Such a slit can be easily formed by simply piercing a perforated blade such as a blade of a cutter. Therefore, the production efficiency of the gas permeable film 2 can be improved. As described above, when the small hole 2c is a small slit having a cut line shape, the length of the slit is not particularly limited, but is 0.1 to 2 cm, particularly 0.5
The thickness is preferably set to 1 cm, whereby the vapor pressure can be satisfactorily discharged to the outside, and the outflow of the liquid component inside can be reliably prevented. Although not particularly limited, the slit is preferably formed along the length direction of the gas permeable film 2, that is, along the tear cut direction of the film 1a.
When a part of the slit a is torn and peeled off from the easy peel surface 2a of the gas permeable film 2, it is possible to reliably prevent the slit from being enlarged by being torn.

A partially unsealed portion 3 is formed at a position corresponding to one end of the gas permeable film 2 on the heat-sealed peripheral portion of the bag body 1. The unsealed portion 3 is, as shown in FIG.
By bending a part of the heat-sealed portion, which adheres the peripheral portions of the films 1a and 1b, into a U-shape, both films 1a and 1b are bent.
The unsealed portion 3 is formed with slit-shaped cuts 4 and 4 at both upper and lower ends thereof, and the end of the film 1a between the cuts 4 and 4 is formed. The portion is a tab portion 5.

This packaging bag a is suitably used for packaging processed foods supposed to be cooked by a microwave oven. In this case, for example, only the upper edge shown by reference numeral 6 in the drawing is left. The bag body 1 is formed as a three-sided bag in which three sides of the peripheral portion are heat-sealed.
Then, after the contents are stored, the unsealed upper edge portion 6 is heat-sealed and hermetically sealed. In this case, vacuum packaging can be performed if necessary.

As described above, the food packaged in the packaging bag 1a of this embodiment is sterilized in a boil (steam) state as it is in a packaged state, and after frozen and stored in circulation, the packaging bag 1 is subjected to heating and cooking in a microwave oven. Can be.

Next, when heating and cooking the contents in the packaging bag a of the present embodiment using a microwave oven, first, as shown in FIG. By tearing along the width direction, the film 1a
Is provided with an opening. In this case, in the packaging bag a,
When the tab portion 5 is pinched and a part of the film 1a is torn along the width direction, the opening is formed in the bag body 1 because the film 1a has a tear-cutting property along the width direction.
Is formed in a strip shape with the width of the tab portion 5 along the width direction of
The opening is formed while the torn film piece is peeled off from the easy peel surface 2 a of the gas permeable film 2, so that a strip-shaped opening is formed on the gas permeable film 2. At this time, since the width of the opening is smaller than the width of the gas permeable film 2, the periphery of the gas permeable film 2 remains heat-sealed to the inner periphery of the opening of the film 1a. The opening is closed by the gas-permeable film.

Here, the tab portion 5 is pinched to remove the film 1
a when the film 1a, 1b
In this case, the heat seal portion to be peeled off for forming the opening is formed by removing the gas permeable film 2 as shown in FIG. This is a portion where the film 1a and the film 1b are heat-sealed, and in this case, the torn film piece heat-sealed on the easy peel surface 2a side of the gas permeable film 2 easily loses the gas permeation. The film 1b (the film on the side that is not torn) forming the bag body 1 is heat-bonded, because it can be peeled off from the conductive film 2 and a so-called easy-peel function is obtained, so that it is excellent in convenience during heating and cooking. The gas permeable film 2 is heat-sealed with the other surface 2b of the gas permeable film 2 having good properties, so that the gas permeable film 2 is torn when forming a tear opening. Without such peeled off from the other film 1b with the film strip, an opening formed in which can be closed reliably in the gas permeable film 2.

In this manner, the opening closed by the gas permeable film 2 is provided in the packaging bag a, and the contents are put into a microwave oven and the contents are cooked together with the packaging bag a in this state. is there. At this time, the vapor pressure generated in the packaging bag a by the heating is discharged to the outside through the small holes 2c of the gas permeable film 2, and by setting the hole diameter of the small holes 2c as described above, the gas permeability is reduced. The film 2 can reliably prevent the liquid from flowing out of the packaging bag 1a, and can perform good and safe heating and cooking.

In this case, when the small holes 2c are formed as small slits formed by cutting the small holes 2c as described above, the entire surface of the easy peel surface 2a of the gas permeable film 2 is covered with the bag body. When the film is to be thermally bonded to the film 1a to be formed, both edges of the slit may adhere to each other and become closed. In this case, the internal pressure of the packaging bag increases due to the vapor pressure generated during heating and cooking. The slit is opened so as to pop, and the vapor pressure can be reliably discharged out of the packaging bag through the slit.

In this embodiment, two films 1
The bag body 1 was formed by superimposing a and 1b on each other and heat-sealing the four edges thereof. However, by folding one film into two and superimposing, and heat-sealing the three edges of the film. A bag body may be formed, and as shown in FIGS. 7 and 8, two films 1a and 1b are overlapped and a third film 1c made of a similar material is provided at the lower end thereof. By folding and sandwiching and heat-sealing the peripheral portions of the three films 1a, 1b, 1c, a self-supporting packaging bag (standing pouch) b having a bottom wall is formed as shown in FIG. Can also. Note that the other configurations and operational effects of the packaging bag b shown in FIGS.
Is the same as that of the packaging bag a shown in (1), the same components are denoted by the same reference characters, and description thereof is omitted.

As described above, according to the packaging bag of the present invention, a completely sealed state can be maintained at all times, and various characteristics required for food packaging bags such as good heat resistance, gas barrier properties, and seal strength. Vacuum packaging → boil (steam)
In addition to being able to satisfactorily contribute to the process of sterilization → frozen distribution and storage, when cooking the food contained inside in a microwave oven together with the packaging bag, it is possible to discharge the steam generated during heating and cooking properly and safely. You can do it.

Next, experimental examples will be shown to specifically show the effects of the present invention. [Experimental example 1] A film obtained by laminating a polypropylene film (thickness: 25 µm) uniaxially stretched in the tear-cut direction and a non-stretched polypropylene film (thickness: 60 µm) is used as the films 1a and 1b for the bag body 1, and is not stretched. A polypropylene film (thickness: 20 μm) and a polypropylene / polystyrene polymer alloy film (thickness: 30 μm) are combined with a polyester film (thickness: 12 μm).
μm) is sandwiched therebetween, and a band-like film having a large number of round holes with a hole diameter of 200 μm is used as a gas-permeable film 2 to produce a packaging bag similar to the packaging bag a shown in FIGS. did.

At this time, first, a three-sided bag is heat-sealed by leaving only the upper edge portion of the bag main body 1 shown by reference numeral 6 in FIGS. 1 to 3 and then filled with 150 g of cooked rice from the upper end opening. The bag was sealed by heat-sealing the upper end opening under reduced pressure to obtain a vacuum packaging pack.

After the vacuum packaging pack is stored in a refrigerator for one day, an opening closed by the gas permeable film 2 is formed in the film 1a according to the above-described procedure, and the opening is put sideways in a microwave oven to 500 watts. For 5 minutes.
At this time, the pressurized steam was discharged out of the packaging bag a through the small holes 2c of the gas permeable film 2, and the cooked rice was successfully heated to 100 ° C. without damage such as bag breakage.

[Experimental example 2] 150 g of rice porridge with contents cooked
An experiment similar to that of Example 1 was performed except that the above was set. At this time, the porridge was well heated to 100 ° C. without any damage such as outflow of water and breakage of the bag.

Although the present invention has been described in detail with reference to examples and experimental examples, the packaging bag of the present invention is not limited to the above-described examples, and the configuration thereof can be appropriately changed. For example, in the above Examples and Experimental Examples, the entire surface of the easy peel surface 2a of the gas permeable film 2 was heat-sealed to the film 1a forming the front side of the bag body 1.
Only the peripheral portion of the easy peel surface 2a may be heat-sealed to the film 1a. In the above-described embodiment and experimental example, the unsealed portion 3 is partially formed on a part of the heat-sealed portion of the peripheral portion of the bag body 1. And the cuts 4, 4 were formed in the unsealed portion 3 to form the tab portion 5, but the peripheral portion of the bag body 1 was uniformly heat-sealed and formed so as to extend from the front film 1a. A tongue-shaped tab may be provided so as to protrude from the edge of the bag body 1.
Furthermore, other configurations such as the form of the bag body 1 and the position where the opening is formed may be variously changed without departing from the gist of the present invention.

Furthermore, the packaging bag of the present invention is suitably used for packaging foods, particularly foods intended for cooking by heating in a microwave oven, as shown in the above Examples and Experimental Examples. However, its use is not limited to this, for example, it is necessary to always keep hermetically sealed such as deodorants, fragrances, desiccants, oxygen scavengers, repellents, etc. It is preferably used for required applications.

[0041]

As described above, according to the packaging bag of the present invention, a completely sealed state can be maintained at all times, and the packaging bag for foods having good heat resistance, gas barrier properties, seal strength and the like is required. Can fully satisfy the required properties, and can be favorably used in the process of vacuum packaging → sterilization of boil (steam) → freezing and distribution and storage. Thus, the steam generated during heating and cooking can be discharged well and safely.

[Brief description of the drawings]

FIG. 1 is a front view showing a packaging bag according to an embodiment of the present invention.

FIG. 2 is a rear view showing the packaging bag.

FIG. 3 is a sectional view showing the packaging bag.

FIG. 4 is an enlarged front view showing a portion where a tab portion of the packaging bag is formed.

FIG. 5 is a front view showing a state when an opening for degassing is formed in the packaging bag.

FIGS. 6A and 6B are schematic cross-sectional views for explaining an operation when forming a gas vent opening in the packaging bag, wherein FIG.
Indicates the time of opening.

FIG. 7 is a front view showing a packaging bag according to another embodiment of the present invention.

FIG. 8 is a sectional view showing the packaging bag.

[Explanation of symbols]

 a, b Packaging bag of the present invention 1 Bag body 1a Front side film (synthetic resin film) 1b Back side film (synthetic resin film) 1c Bottom film (synthetic resin film) 2 Gas permeable film 2a Easy peel surface 2c Small hole 3 Unsealed Part 4 Notch 5 Tab part 6 Upper edge

Claims (3)

[Claims] 1. A packaging bag formed by laminating a plurality of heat-adhesive synthetic resin films, or by folding a single heat-adhesive synthetic resin film and superimposing them, and heat-sealing the periphery thereof. The double-sided heat bonding in which the bag body is formed by using a film having a tear-cutting property in a certain direction as the above-mentioned heat-adhesive synthetic resin film, and one side of the bag is an easy peel surface having a lower heat bonding strength than the other side. A gas permeable film in which a number of small holes are perforated in an elastic strip film is arranged in the bag main body along the tear-cut direction of the synthetic resin film constituting the bag main body, and both end portions thereof are formed as described above. The heat-sealing portion of the bag body peripheral portion is interposed between the films and heat-sealed integrally, and the entire surface or the peripheral portion of the easy peel surface of the gas permeable film is placed on one side of the bag body. A packaging bag characterized in that the synthetic resin film to be formed is heat-sealed and a tab portion is formed at a position corresponding to an end of the gas permeable film of the synthetic resin film forming one surface side of the bag body. . 2. A partial unsealed portion is formed at a position corresponding to an end of the gas permeable film on the periphery of the bag body, and a pair of cuts are formed in the unsealed portion at predetermined intervals. 2. The packaging bag according to claim 1, wherein the space between the cuts is a tab portion. 3. The packaging bag according to claim 1, wherein the small holes formed in the gas-permeable film are holes having a hole diameter of 50 to 2000 μm.