JP2005350102A - Package for heating by microwave oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for heating by a microwave oven maintaining a superior food preservation capability and capable of being heated directly by the microwave oven without requiring work of unsealing the package. <P>SOLUTION: The package is made of one or two or more packaging materials at least including a packaging film, and comprises an inner space which is formed by sealing together an open end where the packaging materials are overlapped, a package body which is formed of walls facing the inner space, and sealed parts which are formed by sealing together the overlapped packaging materials at the open end or other parts. A gas venting means is so formed at least in an area on the walls composed of the packaging material films, in which a stress is concentrated by an increase by heat in the inner pressure of the package body, as to make a score on the packaging material film in the area. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a microwave oven packaging body that can prevent bursting when heated in a microwave oven.

  When cooking frozen foods or chilled foods sealed in a packaging body such as a packaging bag or a tray-type container with a lid using a microwave oven, heating the package while sealed will increase the internal pressure of the packaging body and cause the packaging body to burst. May end up. As the package may burst, food in the package, especially fluid food, may scatter, so the package can be opened before heating or pre-vapoured in the packaging to prevent its bursting. There has been proposed a method for releasing steam generated by heating to the outside of the package, such as providing a hole or valve.

  For example, Patent Document 1 describes a method of forming a degassing through hole along the release agent by applying a release agent to a sealing surface of a plastic container, by an internal pressure generated during microwave heating. . Also, a double-structured bag in which an inner bag made of a material whose tensile strength is weaker than that of the outer bag is provided inside the outer bag, and a small hole for air venting is provided in the outer bag, and food is packaged Patent Document 2 describes a microwave heating packaging member in which the inner bag is not in close contact with the outer bag. Further, in Patent Document 3, a wing seal portion protruding from the bag body is formed on the back portion of the packaging bag, a control seal portion and a point seal portion having a weak seal strength are provided on the wing seal portion, and the point seal portion is provided with the wing seal portion. A method of applying easy steaming means such as notches is described. Further, in Patent Document 4, a flange formed around the opening edge is provided with a rib for attaching a top seal, and a part of the rib is bent inward, or at least a part of the flange is formed. A sealed tray-type container having a concave portion bent inward is described.

Japanese Patent Laid-Open No. 10-42800 JP-A-11-268780 JP 2003-155070 A JP 2001-328686 A

  However, the method of opening the package before heating takes time, and if this operation is forgotten, the package may be ruptured. On the other hand, a package using a packaging material in which holes have been perforated is not preferable in terms of preserving the food as the contents, and the bag strength remains uneasy. For this reason, it has been proposed to seal the hole with a material having a barrier property, but it is necessary to peel off the barrier seal before heating. There is a possibility to forget.

  In addition, as described above, a method of applying a release agent to the seal part (Patent Document 1) or providing a point seal part with a weak seal strength (Patent Document 3) causes the gas vent hole to be removed by peeling the seal part. It is formed, and it is necessary to control so that a seal | sticker part peels on preferable conditions, such as temperature and a pressure. Moreover, the packaging body provided with the complicated degassing means has a problem that the bag making process becomes complicated and the manufacturing cost becomes expensive.

  The present invention has been accomplished in view of the above-described circumstances, and is a microwave heating packaging that can be heated in a microwave oven as it is without requiring an operation such as opening the package while maintaining excellent food storage stability. Provide the body.

  The packaging body for heating a microwave oven according to the present invention includes one or more packaging materials including at least a packaging material film, and an internal space formed by sealing an open end where the packaging materials overlap each other, and an internal space A packaging body for heating a microwave oven, comprising a packaging body body constituted by a wall facing the packaging body, and a sealing part that seals the packaging material overlapped at the open end or other position, comprising the packaging material film In the region where the stress of the internal pressure is concentrated when the internal pressure of the package body rises due to at least heating of the wall portion to be heated, a degassing means is provided in which the packaging film in the region is subjected to scar processing. It is what.

  The microwave oven heating package of the present invention is provided with a gas venting means that makes it easy to break the packaging material by applying scratch processing in a region where stress is strongly applied when the internal pressure of the package body rises as described above. Thus, the packaging material in the region where the gas venting means is provided is broken by the internal pressure of the package during heating, and a gas vent hole is automatically formed. Therefore, it is possible to cook with a microwave oven as it is without taking the trouble of opening the package to unseal the package before heating, and there is no risk of the package rupturing, so food is not scattered. . Further, the scar processing for forming the gas venting means can be easily performed without requiring complicated steps and adjustments. The form of the package of the present invention is not particularly limited, and examples thereof include forms such as a packaging bag and a packaging container.

  The microwave oven packaging bag of the present invention is composed of one or two or more packaging material films, an internal space formed by sealing the open end where the packaging material films overlap, and a wall facing the internal space A packaging body for heating a microwave oven comprising: a bag body constituted by a portion; and a sealing portion that seals the packaging film overlapped at the open end or other position, wherein at least the bag body of the wall portion is heated. In the region where the stress of the internal pressure is concentrated when it swells, a degassing unit is provided in which the packaging film in the region is subjected to scar processing.

  The area to be subjected to scar processing for forming the gas venting means is not particularly limited as long as the gas venting means formed by the scar processing is an area to which stress is strong enough to break, and the seal portion and the wall are not limited. The gas venting means can be provided in a region including a boundary portion with the portion or a region away from the seal portion at the open end.

  In the case where the scratch processing of the degassing means is performed across the wall portion and the seal portion, the seal strength of the seal portion not subjected to the scratch processing is 4.9 to 98 N / 15 mm (0.5 to 10 kgf / 15 mm), by applying the scar processing so that the seal strength of the seal portion subjected to the scar processing is 5 to 70% of the seal strength of the seal portion not subjected to the scratch processing, A gas venting means having an appropriate breaking strength can be provided.

In the case where the bag has a shape having a short side and a long side, it is preferable to provide a gas venting means at or near the center in the longitudinal direction of the bag body to which particularly strong stress is applied.
The packaging film is a laminated film of two or more layers including a base material layer and an inner surface layer, and in the region where the degassing means is provided, it is one layer or two or more layers including the base material layer of the laminated film. In the case where a layer that has been subjected to scar processing and a layer that has been subjected to scratch processing is laminated separately from a layer that is not subjected to scratch processing or a base material layer, an area where gas venting means is provided This is preferable because the airtightness of the food can be kept high, and the preservability of the food as the contents of the packaging bag is improved.

  The packaging film is a laminated film of two or more layers including a base material layer and an inner surface layer, and the region provided with the degassing means includes a laminated portion including at least the base material layer and an inner surface layer. In the case of a multi-wall structure in which a plurality of laminated portions including each other are overlapped without being joined, since the base material layer subjected to scar processing is easily broken, even in a region where stress due to internal pressure is not concentrated so much It is possible to provide a gas venting means that is easy to break. Moreover, since the time until the vent hole is formed becomes longer, the steaming effect of the food is increased.

In the packaging bag of the present invention, a seal portion is intentionally provided at another position away from the seal portion at the open end in the region where the stress of the internal pressure of the wall portion is concentrated, and the scar processing is performed on the other By applying to a region including a boundary portion between the seal portion of the position and the wall portion, it is possible to provide a region where stronger stress is concentrated at an arbitrary position.
If the degassing means is provided only on the wall portion constituting one surface side of the bag body, the surface from which the degassing means is provided is heated to the upper side, thereby heating the degassing holes from the degassing holes. The spilling of food can be prevented.

  The microwave heating packaging container of the present invention comprises a tray-type container and a lid, and at least an internal space formed by sealing the open end where the tray-type container and the lid overlap each other, and a surface facing the internal space. A container body constituted by a wall portion, a tray-type container that overlaps at the open end or other position, and a lid portion or a sealing portion that seals the lid materials, At least a part of the lid material is made of a packaging material film, and at least a scar on the packaging film in the region in the wall portion constituted by the packaging material film is concentrated in an area where the internal pressure stress is concentrated when the packaging container body is expanded by heating. A degassing means that has been processed is provided.

  According to the present invention, the gas venting hole is automatically formed when the gas venting means breaks due to an increase in the internal pressure of the packaging body such as a packaging bag or a packaging container during cooking by a microwave oven. Therefore, even if it heats as it is, without performing the operation | work of opening the said package body etc. before cooking, there is no possibility that a package body may burst. Scratch processing to form the gas venting means can be applied to the packaging material without requiring complicated processing steps, and the gas venting means formed by the scar processing can easily adjust the breaking strength. is there. In addition, unlike the case where cooking is started in a state where the vent holes are opened in advance, a high internal pressure is applied until the vent holes are formed, so that a steaming effect of food can be obtained. Furthermore, since the degassing holes are formed only when the internal pressure of the package rises to the extent that the degassing means breaks, it has good sealing properties and excellent food preservability as the contents of the package. is there.

In addition, when the degassing means is provided only on one surface side constituting the package body, for example, only on the one surface side constituting the bag body or the lid material of the packaging container with lid, the surface on which the degassing means is provided. By placing and heating in the microwave oven in a state in which is placed on the upper side, it is possible to prevent the food from spilling through the vent hole.
Also, improve the airtightness of the packaging bag by devising the laminated structure of the packaging film so that there are no holes completely penetrating in the thickness direction of the packaging film in the area where the scar has been processed, It is also possible to increase the steaming effect at the time of cooking by making the packaging film at the position to be provided with a multi-wall structure.
Further, the range of the area where the gas venting means can be installed by intentionally providing an area where stress due to the internal pressure when the bag is inflated is intentionally provided with a multiple wall structure at the position where the gas venting means is provided. It is possible to increase the degree of freedom of the installation position.

  The packaging body for heating a microwave oven according to the present invention includes one or more packaging materials including at least a packaging material film, and an internal space formed by sealing an open end where the packaging materials overlap each other, and an internal space A packaging body for heating a microwave oven, comprising a packaging body body constituted by a wall facing the packaging body, and a sealing part that seals the packaging material overlapped at the open end or other position, comprising the packaging material film In the region where the stress of the internal pressure is concentrated when the internal pressure of the package body rises due to at least heating of the wall portion to be heated, a degassing means is provided in which the packaging film in the region is subjected to scar processing. And

  In the present invention, the package is formed by sealing at least the open end where at least the packaging material overlaps by appropriately folding and / or overlapping one or more packaging materials including at least the packaging material film. The form is not particularly limited. As a packaging material, in addition to the packaging material film, it is possible to maintain the airtightness of the food that is the contents of the packaging body, such as a packaging material formed in a tray shape, etc., and is heat resistant that can be cooked by a microwave oven A packaging material having properties can be used. Specific examples of the package include a packaging bag or lid formed by folding and / or overlapping and / or cylindrical shape of a packaging film as will be described later, and sealing the open end where the packaging film overlaps. At least a part of the material is a packaging material film, and the open end of the lid material and the open end of the tray packaging material are overlapped and sealed so as to seal the opening (open end) of the packaging material formed in the tray mold. The packaging container etc. formed by this can be mentioned, However It is not limited to these.

  The microwave oven heating package of the present invention is characterized in that a gas venting unit is provided that has a scratch processing in a region where the stress of the internal pressure is concentrated when the internal pressure of the package body is increased by heating at least the wall portion. When the internal pressure rises, the degassing means breaks and a degassing hole is formed, thereby releasing the steam or expanded gas generated during heating in the package to the outside, and the package bursts. Can be prevented. In the present invention, among the packaging materials forming the packaging body, the degassing means is provided in the packaging film that is thin and flexible and has a relatively low breaking strength, and among the packaging film, Since the degassing means is provided in the region where the stress of the internal pressure is concentrated when the internal pressure rises, the degassing means has good breakability when cooking in the microwave oven.

Hereinafter, the microwave oven heating package of the present invention will be described in detail by taking a packaging bag as an example.
The microwave oven packaging bag of the present invention is composed of one or two or more packaging material films, an internal space formed by sealing the open end where the packaging material films overlap, and a wall facing the internal space A packaging body for heating a microwave oven comprising: a bag body constituted by a portion; and a sealing portion that seals the packaging film overlapped at the open end or other position, wherein at least the bag body of the wall portion is heated. In the region where the stress of the internal pressure is concentrated when it swells, a degassing unit is provided in which the packaging film in the region is subjected to scratch processing.

The packaging bag according to the present invention is formed by folding and / or stacking and / or cylindrical shape of one or more packaging material films and sealing the open end where the packaging material films overlap each other. Is not particularly limited. For example, a flat bag as shown in FIG. 1 or a palm bag as shown in FIG. 6 may be used. In addition, a thick shape having a side surface or a shape other than a rectangle may be used.
In FIG. 1, a flat bag type microwave heating packaging bag 101 is a heat-sealed portion 1, 2, 3, 4 in which two packaging materials are overlapped and the open ends existing at the upper, lower, left and right edges are sealed. Is provided. By providing each seal portion, an internal space is formed, and the bag body is constituted by the two wall portions 5 and 6. The sealing method at the open end and other positions is not limited to heat sealing, and a generally known method such as ultrasonic sealing or sealing with an adhesive may be applied.

  The packaging film is not particularly limited as long as it is a film having heat resistance capable of maintaining the hermeticity of the food as the contents and capable of being cooked by a microwave oven. Or a multilayer plastic film, a metal film, an inorganic vapor deposition layer, a multilayer plastic film optionally including a paper layer, and the like are mentioned, but in general, a laminated film of two or more layers including at least a base material layer and an inner surface layer Is used. The base material layer is a layer having a relatively large strength among the layers constituting the laminated film, and usually has the largest strength, and has a central function of forming a packaging bag, and has a gas barrier property if necessary. It is a layer that also has functions such as light shielding properties and printability. The base material layer may be a single layer structure or a multilayer structure in which a plurality of layers are laminated. For example, polyester such as vapor-deposited polyethylene terephthalate (VMPET), stretched polypropylene (OPP), stretched such as high-density polyethylene (HDPE) A stretched film layer such as polyolefin, stretched nylon (ONY), ethylene vinyl alcohol copolymer (EVOH) or the like and a laminate of these stretched film layers are used. As a layer constituting the base material layer, a printing layer that accepts printed display is provided to enhance aesthetics, or a transparent vapor deposition layer such as alumina or silica or a metal foil layer such as aluminum foil is provided to provide a barrier property. Can do. Among these, as the layer having barrier properties, a transparent vapor deposition layer or the like is preferable because no spark is generated, and an aluminum vapor deposition layer or an aluminum foil layer is generally not preferable because it generates a spark.

  On the other hand, the inner surface layer forms the innermost layer of the packaging bag and is usually a heat seal layer depending on the bag making method. For example, linear low density polyethylene (LLDPE), unstretched polypropylene (CPP), low density An unstretched film layer such as polyethylene (LDPE) or ethylene vinyl acetate copolymer (EVA) is used. The packaging material film may include other layers such as a barrier layer as necessary within the range not impairing the object of the present invention, in addition to the base material layer and the inner surface layer.

Specific examples of the laminated film include the following, but are not limited thereto. In the following examples, the symbol “#” represents the thickness (unit: μm) of the corresponding layer.
Specific Example: Substrate Layer with Scratch Processing [Transparent VMPET # 12 / ONY # 15] / Inner Layer [LLDPE # 50]; Substrate Layer with Scratch Processing [Transparent VMPET # 12] / Inner Layer [LLDPE # 50]; Substrate layer with processing [ONY # 15] / Inner layer [LLDPE # 50]; Substrate layer with scratches [OPP # 20] / Inner layer [LLDPE # 50]

The packaging bag 101 in FIG. 1 has a rectangular shape, and extends from the seal portion side to the wall portion side facing the internal space across the inner edge of the seal portion at the center of the longitudinal seal portion on one side (position of L / 2). The gas venting means 7 is provided in the region.
In the present invention, the degassing means is a region that is easily broken when compared to the surrounding region when the internal pressure of the bag is increased by applying a scar process to a predetermined region of the packaging material film. From the vent hole formed when the venting means breaks as the internal pressure of the bag rises, water vapor generated during heating, air or other gas filled in the packaging bag expanded by heating, etc. In order to prevent the packaging bag from being ruptured, gas venting means is provided. Scar mark processing is a process of forming a dense surface of scratches such as fine irregularities and fine through holes in a predetermined region of the packaging material film. The scratch may be a small hole or perforation that penetrates the film as long as it facilitates breakage of the film, or may be a rough surface composed of non-penetrating irregularities, or may be non-penetrating with the through-hole. It may be a mixture of unevenness. When the packaging film is a laminated film, the scratches may be formed only on a part of the layers including the base material layer having the highest strength, or may be formed on all the layers included in the laminated structure. Although it is good, for the purpose of scratch processing for facilitating breakage of the film, it is preferable to perform scratch processing on at least the strongest substrate layer.

  When forming a scar in a plurality of layers in the laminated film, a plurality of layers in which the scar is formed may be laminated adjacent to each other, and a layer having no scar is interposed between the layers in which the scar is formed. May be. FIG. 2 shows a specific example in which a layer subjected to scar processing and a layer not subjected to scratch processing are stacked in the region of the gas venting means.

  In FIG. 2A, the transparent VMPET film 8a and the ONY film 8b are laminated and bonded to each other, and the base film (base material layer 8) on which the scars are processed in the region serving as the gas venting means 7 has an anchor coat or The packaging material film which formed the heat seal inner surface layer 9 by extruding and laminating LLDPE after the base treatment is shown. In this case, the transparent VMPET film 8a and the ONY film 8b have the through-holes 10, but the ventilation from the outside is blocked by the coating with the inner surface layer and the LLDPE of the extrusion lamination filled in the through-holes.

  FIG. 2B shows the ONY of the base film (base material layer 8) in which the two films are laminated and bonded after the scratch processing is performed on the regions to be the gas venting means 7 of the transparent VMPET film 8a and the ONY film 8b. On the film 8b side, a packaging material film in which LLDPE is dry-laminated to form the heat seal inner layer 9 is shown. In this case, the region serving as the gas venting means of the transparent VMPET film 8a and the region serving as the gas venting means of the ONY film 8b have through holes 10a and 10b and are aligned and laminated. In addition, the positions of the through hole 10a and the through hole 10b are shifted, and the outside air flow is blocked by the adhesive and the inner surface layer filled in the through hole of the ONY film 8b.

  In FIG. 2C, a gas is removed on the side of the ONY film 8b of the base film (base material layer 8) in which the ONY film 8b is laminated and adhered after the scratch processing is performed on the region to be the gas releasing means 7 of the transparent VMPET film 8a. The packaging material film which formed the heat-sealing inner surface layer 9 by dry-laminating the LLDPE film which performed the scratch process in the area | region used as the means 7 is shown. In this case, the transparent VMPET film 8a and the inner layer 9 have a through hole in the region serving as a degassing means, and are aligned and laminated and bonded, but the ONY film 8b does not have a through hole between the two films. Since the layer is interposed, ventilation from the outside is blocked.

  For example, as shown in FIG. 3, a film layer 12 to be scratched out of the layers constituting the packaging film is caused to run by a driving roller 11 and the driving roller is sanded as shown in FIG. 3. There is a method in which the sand roller 14 holding the paper 13 is separated and contacted at a predetermined pitch while rotating. In this way, it is possible to rough the surface at a desired position. By appropriately adjusting the particle size of the sandpaper, it is possible to give a desired breaking strength to the degassing means formed by scar processing. As the sandpaper, for example, a particle size of about 60 to 120 is preferable, and about 80 is particularly preferable. Further, as the scar processing, perforation may be performed by a known method. The method of scratch processing is not limited to the method using the sandpaper, and for example, means such as laser light, corona discharge, and plasma discharge can be used.

The degassing means provided in the packaging bag of the present invention can adjust its breaking strength by appropriately adjusting the degree of scar processing (for example, the size, depth, number, etc. of the scratches), as described above. It is formed by scratch processing that can be easily applied.
As a preferable state of the scar, for example, a rough surface made of non-penetrating irregularities obtained by using a sandpaper having a particle size of 80 as described above, and a processed member in which a plurality of blades having a length of 0.5 mm are closely packed. A plurality of rows of perforations obtained by using the above are mentioned.
The shape, size, etc. of the gas venting means may be adjusted as appropriate according to the size of the packaging bag, the material of the packaging film used, the laminated structure, and the like.

  In order to increase the airtightness of the region provided with the gas venting means, the packaging material film is a laminated film of two or more layers including a base material layer and an inner surface layer, and in the region provided with the gas venting means, Scratch processing is applied to one layer or two or more layers including the base material layer of the laminated film, and a layer subjected to scratch processing is provided separately from a layer that is not subjected to scratch processing or a base material layer. It is preferable that they are laminated. At least one layer including a base material layer is subjected to scar processing, thereby giving good destructibility to the degassing means, and a base layer subjected to the scar processing and a layer not subjected to the scratch processing; Before the breakage due to the expansion of the bag occurs by laminating the base material layer that has been laminated or scratched and the layer that has been scratched separately from the base material layer so that the scratch positions are different from each other. Can prevent a hole completely penetrating the thickness direction of the film, and a highly airtight packaging bag can be obtained. As a result, it has the advantage that the preservability of the food, which is the contents of the packaging bag, is improved while having good degassing means.

  A laminated film having a gas venting means is a film made of a base material layer which is subjected to scratch processing, and this base material is melted resin or, if necessary, by a conventionally known general lamination method such as extrusion and drying. It is obtained by laminating other films which have been subjected to scratch processing. When performing scar processing on two or more films, the gas venting means having the scar processing portions in two or more layers can be obtained by aligning and overlapping the scar processing portions formed on each film and laminating and bonding them. Can be formed.

  In addition, when the internal space of the scar forming the gas venting means is filled with an inner surface layer or an adhesive, the gas barrier property is further improved. Therefore, in order to prevent the contents from being oxidized, nitrogen gas or the like is not contained in the bag. It can also be applied as an aerated packaging bag filled with active gas. As a method for filling the inside of the scar, an adhesive layer or the like may be inserted into the concave portion of the scar processed portion by an extrusion laminating method, or an adhesive may be inserted into the concave portion in the case of the dry laminating method.

  The venting means is provided in a region where the stress distribution of the internal pressure is higher than the surroundings when the bag is inflated so that the region of the venting means is automatically broken before the bag bursts. A suitable position is determined according to the form of the packaging bag to be performed. The area where the internal pressure stress distribution is higher than the surrounding area when the bag is inflated is preferably the position where the internal pressure stress is the strongest among the parts of the bag body, but the position where the stress is concentrated more than the surrounding area. If it is. Therefore, it does not exclude the provision of the gas venting means at a position other than the region where the internal pressure stress is the strongest, and the gas venting means may be provided at a plurality of positions.

When the bag is rectangular like the packaging bag 101 in FIG. 1, when the bag is heated by a microwave oven, it swells due to an increase in internal pressure, and the stress of the internal pressure tends to concentrate on the central portion (position L / 2) in the longitudinal direction. . Therefore, by providing a degassing means 7 having a reduced breaking strength at the longitudinal center of the wall portion of the packaging bag, the degassing means for the wall portion is provided when the packaging bag is inflated by heating in a microwave oven. The area is pushed and broken by the internal pressure from the internal space, and a vent hole is formed. As a result, the gas is released to the outside and the bag is prevented from rupturing due to excessive expansion.
In the swelled packaging bag at the time of heating, the central part in the short side or the long side of the bag swells most, so that the stress of the internal pressure tends to concentrate on the central part. As shown in FIG. 4, the center portion in the longitudinal direction of the bag body is subjected to particularly strong stress because the load applied to a longer distance than the short direction is concentrated at one point. Therefore, when the bag has an elongated shape (for example, a rectangle or an ellipse) having a short side and a long side, a gas venting means is provided at or near the center of the bag in the longitudinal direction. Preferably it is.

  In general, when a bag body in which contents such as food are sealed is heated by a microwave oven, gas such as water vapor is generated or expanded in the bag as the temperature rises, the internal pressure of the bag increases, It swells and bursts when it swells excessively. On the other hand, when the packaging body using the packaging bag of the present invention is heated using a microwave oven, the degassing means provided in the region where the stress is strongly applied when the packaging bag swells due to an increase in internal pressure. This area is automatically broken and a vent hole is formed. Therefore, even if an operation such as opening the packaging bag in advance before heating is not performed, the packaging bag does not rupture, so there is no risk of food scattering. Furthermore, since the vent hole is formed only when the internal pressure of the packaging bag rises to such an extent that the gas venting means breaks, the hermeticity is good and the preservability of the food as the contents of the packaging bag is excellent. Moreover, unlike the case of opening the packaging bag in advance before heating or opening a hole in the packaging bag and starting cooking with the gas vent hole formed, the scratched part is broken and the gas vent hole is opened. Since the packaging bag is kept sealed until is formed, a high internal pressure is applied to the food in the packaging bag, and the steaming effect of the food can be obtained.

  In addition, conventionally, a method of adjusting the seal strength by changing the heat sealing material and the heating condition at the time of sealing is known in order to form a weak seal portion that becomes a vent hole of the bag. Therefore, it is relatively difficult to finely and accurately adjust the seal strength. On the other hand, the degassing means used in the present invention is formed by scar processing, and its breaking strength can be adjusted relatively easily.

  As shown in FIG. 1, the gas venting means is preferably provided in a region including the boundary portion between the seal portion and the wall portion in relation to the position of the seal portion. Further, among the regions including the boundary between the seal portion and the wall portion, the region located in the central portion in the longitudinal direction of the bag body or in the vicinity thereof is particularly concentrated in the stress of the internal pressure. Particularly preferred. Here, the region including the boundary portion between the seal portion and the wall portion is a region straddling the seal portion 15 and the wall portion 16 as shown in FIG. 5A or a seal portion 15 and the wall portion as shown in FIG. 5B. A wall portion including the boundary portion 17 with the seal portion 15 is included.

  The sealing portion is not stretchable because the sealing material film is sealed in a state where the wrapping material films are overlapped. Therefore, in a state where the packaging bag is inflated and the packaging material film on the wall portion is stretched, a strong stress is applied to the region including the boundary portion between the seal portion and the wall portion, particularly the boundary portion between the seal portion and the wall portion. Become. When the gas venting means is applied to the region including the boundary portion between the seal portion and the wall portion as described above, when the packaging bag is inflated by the internal pressure generated by heating and the internal pressure increases to some extent, the stress on the boundary portion 17 is increased. The packaging material film begins to break starting from a concentrated location (when the gas venting means is provided at the central portion in the longitudinal direction, it coincides with the central portion of the boundary portion 17), and breaks toward both ends of the boundary portion 17 Advances and a vent hole is formed. When a part of the seal part is also subjected to scar processing as shown in FIG. 5A, the sealing strength of the seal part subjected to the scratch processing is reduced, so that the packaging material along the boundary part 17 The film may be torn, and the seal of the seal portion that has been subjected to scar processing may be peeled off.

  In order to restrict the expansion of the wall portion adjacent to the boundary portion 17 between the seal portion and the wall portion, as shown in FIG. 5B, even when the boundary portion 17 coincides with the edge of the scar processed portion. Although the object can be sufficiently achieved, it is preferable to perform scar processing on a region extending between the seal portion and the wall portion as shown in FIG. 5A from the viewpoint of easy scratch processing.

In the case where scar processing is performed on the seal portion, the seal strength decreases as the degree of scar processing progresses, so the degree of decrease in seal strength can be an indicator of the breaking strength of that portion. Therefore, in the present invention, when the scar part is also processed on the seal part as well as the wall part of the packaging bag, the seal strength of the seal part not subjected to the scar process is 4.9 to 98 N / 15 mm (0). .5 to 10 kgf / 15 mm), the seal strength of the seal portion subjected to scratch processing is 5 to 70% of the seal strength (4.9 to 98 N / 15 mm) of the seal portion not subjected to scratch processing. By processing the scar so that it becomes, it has an appropriate breaking strength as a degassing means that does not break in the storage state and expands easily by heating with a microwave oven and easily breaks when reaching a predetermined internal pressure. Can be obtained. In particular, the seal strength of the seal portion not subjected to scratch processing is in the range of 19.6 to 29.4 N / 15 mm (2 to 3 kgf / 15 mm), which is a general seal strength in a microwave heating packaging bag. In that case, it is preferable that the seal strength of the seal portion subjected to the scar processing is 20 to 60% of the seal strength of the seal portion not subjected to the scratch processing in the above-described range. Specifically, for example, when the seal strength of a seal portion not subjected to scar processing is 24.5 N / 15 mm (2.5 kgf / 15 mm), the seal strength of the seal portion subjected to scratch processing is subjected to the scratch processing. Scratch processing is preferably performed so that the seal strength is 9.8 N / 15 mm (1 kgf / 15 mm), which is 40% of the seal strength of the unsealed seal portion.
Here, as a method for measuring the seal strength, for example, the method described in JISZ0238 “Test method for heat-sealed soft packaging bags and semi-rigid containers” can be used.

  Further, the gas venting means may be provided on any of the wall portions constituting the bag main body, but the gas venting means may be provided only on the wall portion constituting one surface of the bag main body. preferable. In this way, by providing the gas venting means only on the wall portion constituting one surface, if the surface provided with the gas venting means is placed in the upper side in the microwave oven and cooked, When the punch hole is formed, the food can be prevented from being spilled. At this time, it is possible to clearly indicate the usage method to the user by giving a precautionary statement such as “Please heat this side up” on the packaging film that forms the wall with the gas venting means. preferable.

  The packaging bag 102 shown in FIG. 6 is a palm-type packaging bag, and has a wall portion (front surface) 18 and a wall portion (rear surface) 19, and both ends of the packaging material film are attached to the wall portion (rear surface) 19. A heat-sealed back seal portion 20 is formed, and the packaging film formed into a cylindrical body by the back seal portion 20 is bent at two left and right sides, and the upper and lower end edges are heat-sealed to form upper and lower seal portions 21 and 22. Is formed. In FIG. 6, the gas venting means 23 is located at the central portion of the wall portion 19 in the longitudinal direction of the packaging bag, and is located on the wall portion 19 adjacent to the back seal portion 20 from a position inside the outer edge of the back seal portion 20 by a distance W. It is provided in the region located across. In the case where gas venting means are provided around the back seal portion 20 of the packaging bag, when the back seal portion 20 is bent in one direction along the back surface 19 as shown in FIG. As shown in FIG. 6B, it is preferable to provide a gas venting means on the surface 20a of the back seal portion 20 that faces the upper surface when it is bent. When the degassing means is provided on the surface 20a of the back seal portion 20, a stronger stress is applied when pressed by the internal pressure, so that a degassing hole is easily formed, and the degassing function of the formed degassing hole Also gets higher.

The area where the scar processing is performed may be an area away from the seal part at the open end as long as the stress that causes the gas venting means to break is applied. For example, in the central part of the bag body as shown in FIG. Scratch processing can also be performed.
The packaging bag 103 shown in FIG. 7 is a flat bag type packaging bag, which is a heat-seal section 24, 25, 26, 27 in which two packaging material films are overlapped and the open ends existing at the upper, lower, left and right edges are sealed. The bag main body is constituted by the two wall portions 28 and 29. The gas venting means 30 is provided at the center of the bag body.

  In general, the central part of the bag body swells better than the open-end seal part when the packaging bag is heated and inflated by a microwave oven, but since the seal part that restricts the elongation of the packaging film is not adjacent, the stress of the internal pressure is extremely high. It is difficult to concentrate in a narrow area. Accordingly, even if the laminated film in the center portion of the bag body is subjected to scratch processing, the film strength is too high and it may be difficult to break. In such a case, as shown in FIG. 8, a plurality of laminated portions obtained by dividing the region provided with the gas venting means 30 into at least a laminated portion including a base material layer and a laminated portion including an inner surface layer are joined to each other. By making the wall portion of the multiple wall structure overlapped without being damaged, the base material layer subjected to the scar processing is easily broken, and as a result, an appropriate breaking strength as a gas venting means can be obtained. Even when the gas venting means 30 is provided adjacent to the open end seal portion, a multiple wall structure may be used. In this case, the breakage at the boundary between the seal portion and the wall portion becomes easier and will be described later. The steaming effect is also improved.

  FIG. 8 shows an example in which the region where the gas venting means 30 of the packaging bag 103 of FIG. 7 is provided has a multiple wall structure. FIG. 8A is an enlarged view of the gas venting means 30 included in the AA cross section of the packaging bag 103 in FIG. In FIG. 8A, the packaging material film is formed on a base film (base material layer 8) obtained by laminating and bonding a transparent VMPET film 8a that has been subjected to scratch processing in an area to be the gas venting means 30, and an ONY film 8b that has not been subjected to scratch processing. Furthermore, although it is a film in which an LLDPE film (inner surface layer 9) is laminated, in the region of the gas venting means 30, the portion of the inner surface layer 9 overlaps without being bonded to the base material layer 8. In this example, since the ONY film 8b that has not been subjected to scratch processing is bonded to the scratch processing portion of the transparent VMPET film 8a that is the outermost layer, the gap between the base material layer 8 and the inner surface layer 9 is also outside. Ventilation is blocked, which is preferable from the viewpoint of the bag storage function. However, even if the space between the base material layer 8 and the inner surface layer 9 can be vented to the outside in the portion of the multiple wall structure, the airtightness of the inner space of the bag body can be maintained unless the inner surface layer 9 has a through hole. Therefore, the base material layer 8 may have a through hole in the portion of the multiple wall structure.

  When the region of the bag body where the gas venting means is provided has a multiple wall structure, the stretchability of the laminated portion including the base material layer subjected to the scar processing is relatively small, and the stretchable portion of the laminated portion including the inner surface layer is stretched. Due to the relatively large property, when the internal pressure of the bag rises and the bag expands, first, as shown in FIG. 8B, the laminated portion including the base material layer is pushed by the inner surface layer and is broken. Next, as shown in FIG. 8C, the laminated portion including the stretchable inner surface layer expands further outward from the broken portion of the base material layer and then breaks. Therefore, in the case where the region of the gas venting means has a multi-wall structure, it is possible to smoothly break the region due to the expansion of the bag, and the laminated portion including the inner surface layer is broken to form a gas vent hole. Since the time until it is formed becomes long, the effect of increasing the steaming effect when the food contained in the packaging bag is cooked with a microwave oven is also obtained.

  A method of forming a multi-wall structure in which a plurality of laminated portions divided into a laminated portion including at least a base material layer and a laminated portion including an inner surface layer are joined together without joining is not particularly limited. In the joint surface between the laminated portion including the inner layer and the laminated portion including the inner surface layer, an adhesive is applied or an adhesive layer made of an adhesive resin or the like is laminated in a region other than the region where scar processing is performed, and the two laminated portions are joined. For example, a packaging material film having a multi-wall structure can be formed only in the region of the gas venting means.

  In the present invention, the degassing means may be provided at any position of the bag body as long as the stress of the internal pressure is higher than the surroundings when the packaging bag is inflated, but it is separated from the open end seal portion. In the case where the bag is provided in the region, the structure that restricts the extension of the bag as described above often does not exist in the region or in the vicinity thereof, so that the bag is less likely to be broken when the bag is inflated.

Therefore, by deliberately providing a structure that restricts the elongation of the bag in a region where the gas venting means of the bag body is to be provided or in the vicinity thereof, the ease of breaking the gas venting means can be adjusted. The degree of freedom of the installation position can be increased.
As one specific method, when it is desired to provide the gas venting means at a position away from the open end seal portion of the bag body, the seal portion (that is, the open end) is intentionally provided in the region where the gas vent means is to be provided. The gas venting means can be formed by forming a scar on a region including the boundary portion between the other seal portion and the wall portion. The packaging bag provided with such gas venting means is similar to the case where the gas venting means is provided adjacent to the open end seal part, and the boundary part between the other seal part and the wall part when heated in a microwave oven. In this case, a fracture occurs and a vent hole is formed.

  FIG. 9 is an example in which another seal portion that assists the formation of the gas vent hole is provided at a position away from the open end seal portion. The bag body 104 shown in FIG. 9 is a flat bag type packaging bag, which is a heat-seal part 31, 32, 33 in which two packaging material films are stacked and the open ends existing at the upper, lower, left and right edges are sealed. 34 is provided, and the bag body is constituted by the two wall portions 35 and 36. The gas venting means 37 is provided in a region including a boundary portion between the seal portion 38 and the wall portion 36 provided in the vicinity of the center portion of the bag body, and the seal portion 38 is a wall as shown in the sectional view of FIG. 9C. It is formed by sealing the inner surfaces in a state where the packaging film forming the part 36 is picked. As shown in FIG. 9, when the bag has an elongated shape having a short side and a long side, and a gas venting means is provided at the center of the bag body, the long side and the wall 36 of the seal part 38 are provided. When the seal portion 38 is provided so that the boundary portion 39 is parallel to the short side direction of the bag and is located in the center portion of the bag body, and the region including the boundary portion 39 is subjected to scar processing, the fracture occurs. Since it becomes easy, it is preferable.

  The other seal part which assists formation of the gas vent hole provided in the position away from the open end seal part is not limited to the mode shown in FIG. For example, in the embodiment shown in FIG. 9, the seal portion can be provided so that the long side of the seal portion is parallel to the longitudinal direction of the bag.

In this manner, by intentionally providing a seal portion where stress concentrates in a region other than the open end seal portion, a region where stress is further applied to an arbitrary position in the region where stress of internal pressure is concentrated is formed. be able to.
According to this method, compared with the method of reducing the breaking strength of the gas venting means by increasing the degree of scar processing, the gas venting holes are maintained while maintaining high film strength in the state where the contents are stored or distributed. When forming the film, it is possible to provide a good degassing means that is easy to break. Moreover, since the range of the area | region which can install a gas venting means spreads, the freedom degree of an installation position becomes high.

  As a method of forming other seal portions other than the open end, for example, as shown in FIG. 9C, a method of sealing inner surfaces with a packaging film forming a wall portion in a region where a seal portion is desired to be provided. In addition, there is a method of sealing the packaging material film forming the wall portion in the region where the sealing portion is to be provided and the packaging material film forming the opposing wall portion.

  Further, according to the present invention, the shape of the packaging bag can be designed so that the stress of the internal pressure is concentrated at the intended position. For example, it is possible to freely design the position where the gas venting means is provided by deforming the shape of the seal portion at the open end to form a region where the stress of the internal pressure is intentionally concentrated. As a specific example, as shown in FIG. 10, among the heat seal portions 40, 41, 42, 43 with the open ends sealed, a part of the heat seal portions 41, 43 is in the same position in the longitudinal direction of the bag. The gas venting means 44 extends to the inside of the main body and is sandwiched between heat seal portions 41a and 43a provided so as to bite into the bag (region where the stress of the internal pressure formed intentionally concentrates). However, the present invention is not limited to this. By narrowing the distance between the seal portions of the open ends that face each other or close to each other, the region where the stress of the internal pressure is concentrated when the bag is inflated is intended. Therefore, it is possible to provide a gas venting means in the region.

  As described above, the packaging bag has been described as a specific example of the packaging body for heating a microwave oven according to the present invention. However, the form of the packaging body of the present invention is not limited to the packaging bag as described above. The form used as a package, for example, a packaging container as shown in FIG. 11 can be illustrated.

  A packaging container 201 shown in FIG. 11 has a packaging material (tray-type packaging material) formed into a tray mold and a packaging material film that is a lid material of the tray-type packaging material, and has an opening of the tray-type packaging material. The packaging film is overlapped so as to cover, and a flange 45 provided at the opening (open end) of the tray-type packaging material and seal portions 46, 47, 48, 49 are provided in which the open end of the packaging film is heat sealed. ing. Walls 50, 51, 52, 53, 54, and 55 are formed by the side wall and bottom of the tray-type packaging material and the packaging material film that closes the opening, and the packaging container body is configured by these wall portions. . The gas venting means 56 is located in the central portion in the longitudinal direction of the packaging material film and is provided in a region including the boundary portion between the wall portion 55 and the sealing portion 46 of the packaging material film.

  In the present invention, the tray-type packaging material is a packaging material having a concave shape in which a side wall is formed around the bottom portion, having a hardness or rigidity more than the packaging material film, and capable of maintaining its own shape. The angle between the side wall and the bottom part is arbitrary, the side wall may be perpendicular to the bottom part or may be inclined at a predetermined angle, and a part of the wall part may be arcuate.

  In FIG. 11, as the tray-type packaging material, the bottom and the opening are rectangular, and a packaging material having a relatively shallow shape is used, but the shape of the tray-type packaging material is not particularly limited, For example, the depth includes a shallow shape such as a dish shape to a deep shape such as a cup shape, and the bottom and opening are used in various shapes such as a polygon such as a rectangle or a circle. Can do. Furthermore, a tray-type packaging material having a structure in which the interior is divided into a plurality of spaces may be used. In this case, the packaging material film as a lid material is formed so that independent internal spaces are formed as necessary. A seal portion can be provided in addition to the open end, or a plurality of independent packaging films can be used for each internal space, and a gas venting unit may be provided for each partitioned internal space.

  As the packaging material formed into a tray mold, a material generally used as a packaging material for microwave heating can be used. For example, a polypropylene (PP) layer having a thickness of 200 μm and a straight film having a thickness of 30 μm can be used. A laminate sheet obtained by laminating and bonding a chain low density polyethylene (LLDPE) layer with an adhesive may be used. The sheet used for vacuum forming is not limited to the laminated sheet as described above, and a single layer or multilayer plastic sheet, or a multilayer plastic sheet optionally including a barrier layer, etc. can be used. A 250 μm PP single layer sheet may be mentioned. The tray-type container may be formed by a forming method other than vacuum forming.

As a packaging material film used for the lid material, the same materials as exemplified in the above packaging bag and the same packaging material film having a laminated structure can be appropriately selected and used. Among the film layers to be performed, the laminated state of the layer subjected to scratch processing and the layer not subjected to scratch processing can be the same as that of the packaging bag. For example, a substrate layer with a scratched surface (thickness 15 μm ONY layer) and an inner surface layer (thickness 50 μmL LDPE layer) are laminated and bonded with an adhesive.
The shape of the lid is not particularly limited as long as the opening of the tray-type packaging material can be closed and a sealed internal space can be formed, and the outer periphery of the flange of the tray-type packaging material may match the outer shape. You may have the part protruded from the flange outer periphery.

  Moreover, in the packaging container shown in FIG. 11, the lid formed only from the packaging material film is used, but the lid material in the packaging container of the present invention only needs to use the packaging material film for a part thereof, for example, , A sealing material such as a rigid plastic sheet other than a packaging material film and a packaging material film, a rigid plastic sheet integrally formed with a thinner packaging material film, etc. can be used as a lid. . As a rigid plastic, what is used as a material of the said tray type container is mentioned, for example.

  The degassing means is a region where the stress of the internal pressure is concentrated from the surroundings when the internal pressure of the packaging container of the packaging film is increased so that the region of the degassing means is automatically broken before the packaging container is ruptured. The position is appropriately determined according to the form of the packaging container to be used. As described above, when the packaging container is inflated, a strong stress is applied to the boundary portion between the wall portion made of the packaging material film and the seal portion. It is preferable to provide in the area | region including the boundary part of the wall part and sealing part which consist of packaging material films. Here, the seal portion is a seal portion that seals the packaging material film and the tray-type container, a seal portion that seals the packaging material film and other packaging materials (such as the above-mentioned rigid plastic sheet), and the container. It includes a seal part that intentionally seals the packaging material films so that the stress of the internal pressure is concentrated when it swells.

  When a rigid plastic sheet and a packaging film integrally molded as described above are used as a lid material, the thickness (strength) of the boundary between the rigid plastic sheet and the packaging film changes abruptly. Similar to the boundary portion between the wall portion made of the material film and the seal portion, a strong stress is applied when the packaging container swells. Therefore, a rigid plastic sheet and a packaging material film that are integrally molded are used as a lid, and the area including the boundary between the rigid plastic sheet and the packaging material film (that is, the boundary between the thick part and the thin part of the integral molding sheet) is used. Gas venting means can also be provided.

When the food sealed with the packaging container as shown in FIG. 11 is heated by a microwave oven, the internal pressure of the packaging container is generated by the generation of water vapor by heating or the expansion of the gas filled in the packaging container, as in the packaging bag. When the pressure rises and swells, the gas venting means provided in the region where the stress of the internal pressure of the packaging film is concentrated automatically tears to form a gas vent hole. As a result, rupture of the packaging container due to excessive increase in the internal pressure of the packaging container can be prevented.
In addition, about the other point regarding the packaging container for microwave ovens of this invention, it can apply to what was described regarding the packaging bag for microwave ovens of this invention.

It is a figure which shows one example of the microwave oven packaging bag which concerns on this invention. It is a figure which shows the lamination example of the layer which performed the scar process in the area | region of a degassing means, and the layer which has not performed the scar process. It is a schematic diagram of the apparatus which performs a scar process on a film. It is the top view (4A) and sectional drawing (4B) which show the state which the packaging bag swelled. It is a figure which shows an example of the area | region which provides a gas venting means. 6A is a view showing an example of a microwave oven heating packaging bag according to the present invention, and FIG. 6B is a partially enlarged sectional view and a partially enlarged plan view of FIG. 6A. It is a figure which shows one example of the microwave oven packaging bag which concerns on this invention. In the microwave heating packaging bag shown in FIG. 7, it is a figure which shows one example of a case where the area | region which provided the gas venting means was made into the multi-wall structure, FIG. 8A is an expanded sectional view of a gas venting means, FIG. FIG. 8C is a diagram illustrating a process of forming a gas vent hole. 9A is a view showing an example of a microwave heating packaging bag according to the present invention, FIG. 9B is a partially enlarged view of FIG. 9A, and FIG. 9C is an AA sectional view of FIG. 9B. It is a figure which shows one example of the microwave oven packaging bag which concerns on this invention. It is a figure which shows one example of the microwave oven packaging container concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2, 3, 4 ... Heat seal part 5,6 ... Wall part 7 ... Degassing means 8 ... Base material layer 9 ... Inner surface layer 10 ... Through-hole 11 ... Drive roller 12 ... Film which processes a scar 13 ... Sandpaper DESCRIPTION OF SYMBOLS 14 ... Sand roller 15 ... Seal part 16 ... Wall part 17 ... Boundary part of the seal part 15 and the wall part 18 ... Wall part (front surface)
19 ... Wall (back)
DESCRIPTION OF SYMBOLS 20 ... Back seal part 21, 22 ... Heat seal part 23 ... Degassing means 24, 25, 26, 27 ... Heat seal part 28, 29 ... Wall part 30 ... Degassing means 31, 32, 33, 34 ... Heat seal part 35, 36 ... Wall 37 ... Gas venting means 38 ... Sealing part 39 ... Boundary part 40 between the sealing part 38 and wall part 36, 41, 42, 43 ... Heat sealing part 44 ... Gas venting means 45 ... Flange 46, 47 , 48, 49 ... Heat seal part 50, 51, 52, 53, 54, 55 ... Wall part 56 ... Gas venting means

Claims (11)

A package comprising at least one packaging material including at least a packaging material film, and comprising an internal space formed by sealing an open end where the packaging materials overlap each other and a wall portion facing the internal space A microwave oven packaging body comprising a main body and a sealing portion that seals the overlapping packaging material at the open end or other position,
In the region where the internal pressure stress is concentrated when the internal pressure of the package body rises due to at least the heating of the wall portion constituted by the packaging material film, a degassing means is provided in which the packaging film in the region is subjected to scar processing. A package for heating a microwave oven, wherein A bag body composed of one or two or more packaging film, formed by sealing an open end where the packaging film overlaps, and a bag body constituted by a wall portion facing the internal space, and the opening A microwave heating packaging bag provided with a sealing portion that seals the packaging film overlapped at an end or other position;
A microwave oven in which at least a bag body of the wall portion is provided with a degassing means in which a packaging film in the region is subjected to scar processing in a region where stress of an internal pressure is concentrated when the bag body is inflated by heating. Packaging bag for heating.   The packaging film is a laminated film of two or more layers including a base material layer and an inner surface layer, and in the region where the degassing means is provided, it is one layer or two or more layers including the base material layer of the laminated film. The packaging bag for heating a microwave oven according to claim 2, wherein a layer having been subjected to scar processing is laminated separately from a layer which has been subjected to scratch processing and which has not been subjected to scratch processing or a base material layer. .   The packaging film is a laminated film of two or more layers including a base material layer and an inner surface layer, and the region where the degassing means is provided includes at least a laminated portion including the base material layer and a laminated portion including the inner surface layer. The packaging bag for heating a microwave oven according to claim 2 or 3, which has a multi-wall structure in which a plurality of divided laminated portions are overlapped without being joined.   The microwave heating packaging bag according to any one of claims 2 to 4, wherein the scar processing is applied to a region including a boundary portion between the seal portion and the wall portion.   The microwave heating packaging bag according to any one of claims 2 to 4, wherein the scar processing is performed in a region away from the seal portion at the open end.   The wall portion has a seal portion at another position apart from the seal portion at the open end in the region where the internal pressure stress is concentrated, and the scar processing is performed between the seal portion at the other position and the wall portion. The packaging bag for microwave oven heating in any one of Claims 2 thru | or 4 given to the area | region containing a boundary part.   The packaging bag for heating a microwave oven according to any one of claims 2 to 7, wherein the degassing means is provided only on a wall portion constituting one surface side of the bag body.   The packaging bag for heating a microwave oven according to any one of claims 2 to 8, wherein the gas venting means is provided at or near the longitudinal center of the bag body.   Scratch processing of the degassing means is performed across the wall portion and the seal portion, and the seal portion not subjected to scratch processing is a seal of 4.9 to 98 N / 15 mm (0.5 to 10 kgf / 15 mm). The microwave oven heating according to any one of claims 2 to 9, wherein the seal portion having strength and having a scar processed has a seal strength of 5 to 70% of the seal strength of the seal portion not subjected to the scratch processing. Packaging bags. A container body composed of a tray-type container and a cover material, and formed by sealing at least an open end where the tray-type container and the cover material overlap each other, and a container body constituted by a wall portion facing the internal space, and the opening A packaging container for heating a microwave oven provided with a tray-type container that is overlapped at an end or other position and a lid or a seal part that seals the lid together,
At least a part of the lid material is made of a packaging material film, and at least the packaging container body of the wall portion constituted by the packaging material film has a region where stress of internal pressure is concentrated when the packaging container body is expanded by heating. A packaging container for heating a microwave oven, characterized in that a degassing means subjected to scar processing is provided.

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