JP2000007053A - Packaging bag for use in microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously heat and cook kinds of food which are different in cooking time by providing one packaging bag with a housing having a metallic film for shielding microwaves and with a housing made of a plastic film where the microwaves are easily transmittable and by controlling microwave transmittance of the two housings. SOLUTION: In a packaging bag with an internal face comprising a heat seal layer and having two housings, a housing (A) 18 and a housing (B) 19 are divided by a center seal 16, while the housing (B) 19 is made of a plastic laminate film which does not shield microwaves and the housing (A) 18 comprises metallic films 13 such as an aluminum foil laminated to reduce microwave transmittance, thereby providing the packaging bag 1 for use in a microwave oven. Since the housing (A) 18 and the housing (B) 19 are different in microwave transmittance, kinds of food different in cooking time can be simultaneously heated and cooked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag for a microwave oven, in which a plurality of storage sections having different microwave transmittances are formed in the same packaging bag so that contents having different cooking times can be stored in a microwave oven. The present invention relates to a packaging bag that can be heated at the same time.

[0002]

2. Description of the Related Art With the spread of microwave ovens, a large number of packaged foods to be heated or cooked in microwave ovens are on the market. Microwave ovens can be used not only for simply warming bento and prepared foods, but also as cooking utensils, so various kinds of cooked foods and semi-cooked foods are also sold. In particular, cooked frozen foods have been developed and sold in the United States as frozen TV dinners, and various types of packaged foods have been sold for use in microwave ovens. Along with this, a combination of various packaging materials suitable for a microwave oven has been developed. That is, a container in which heat-resistant plastic (polyethylene terephthalate, polypropylene, etc.) is bonded to paper,
Aluminum foil coated with epoxy resin or vinyl resin to improve microwave oven suitability, In order to escape water vapor generated from food during heating cooking, using a breathable packaging material in the packaging bag, There is a method using a water-absorbing sheet to absorb the condensation of steam generated during cooking or the drip from food.

[0003]

When a microwave oven is used for cooking, each material of the cooked food and the semi-cooked food has a different cooking time due to a difference in microwave absorption. It is not possible to achieve the optimal cooking state. Therefore, in order to produce delicious cooked foods, it is necessary to cook foods or ingredients having different cooking times twice or three times and combine the individual cooked products into cooked foods. Also, if there is a thing that does not need to be heated in a lunch box or the like, it is necessary to remove it and heat it with a microwave oven.

[0004] For this reason, a method is used in which each material is packaged using packaging materials having different microwave transmittances, and the packaging bags are heated and cooked at the same time. In addition, it is often necessary to perform cooking such as seasoning. In order to solve these problems, the present invention provides, in the same packaging bag, a storage portion having a metal thin film for shielding microwaves and a storage portion made of a plastic film and easily transmitting microwaves. By controlling the microwave transmittance of, foods with different cooking times can be heated and cooked simultaneously.

[0005]

Means for Solving the Problems In order to solve the above problems, the structure of the packaging bag is as follows. In a packaging bag having a plurality of storage portions, a metal thin film is provided in at least one storage portion so that the microwave transmittance is different from that of the other storage portions. Further, in the packaging bag, the metal thin film is made of an aluminum foil or an aluminum vapor-deposited film, and the inner surface layer is a resin having a heat sealing property, and further, each of the storage sections is divided by a heat seal. This was a microwave packaging bag. The heat seal portion, which divides the storage portion having the metal thin film and the other storage portion, is formed to have a lower heat seal strength than the other heat seal portions of the packaging bag. It was a packaging bag. Further, an end face of the metal thin film is covered with a synthetic resin layer, and a corner portion of the metal thin film is formed in a round shape.

That is, in the packaging bag for a microwave oven of the present invention, a plurality of storage portions are formed in one packaging bag, and at least one of the storage portions has a metal thin film made of an aluminum foil or an aluminum vapor-deposited film. A layer is provided so that the microwave transmittance is different from that of the other storage sections so that foods having different cooking times can be simultaneously heated and cooked. Further, the control of the microwave transmittance of the storage section provided with the metal thin film layer was performed by changing the area ratio of the aluminum foil. That is, when the microwave is completely shielded, an aluminum foil is provided on the entire surface of the storage portion, and in order to transmit a certain amount of microwaves, the aluminum foil is formed in a stripe shape in the storage portion. Was adjusted by changing the area ratio. Further, the microwave transmittance can be changed by changing the thickness of the aluminum vapor-deposited film.

In the packaging bag for a microwave oven according to the present invention, the inner surface layer is made of a resin layer having a heat sealing property, and the storage section having the metal thin film and the other storage section are divided by heat sealing. The heat-sealing strength is weaker than other heat-sealing parts (upper and lower sealing parts and side seal parts of the packaging bag), and when the contents are heated and cooked, the storage part expands due to the vapor pressure of the contents. The weak heat seal was broken to allow the two foods to mix.
For example, when spaghetti and sauce are simultaneously processed in microwave ovens in separate storage units, when spaghetti is completely heated and cooked and the storage unit expands due to vapor pressure, the weak heat seal part is broken by the expansion force. Can be mixed with spaghetti and sauce.

Further, the packaging bag for a microwave oven of the present invention is covered with a synthetic resin layer so that no spark is generated by laminating a metal thin film (aluminum foil) and the end face of the aluminum foil is not exposed. The corners of the aluminum foil were rounded in order to prevent the occurrence of sparks at the corners of the aluminum foil to be laminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an example of a packaging bag for a microwave oven according to the present invention. FIG. 2 shows a layer configuration of the packaging bag for a microwave oven of the present invention, and is a cross-sectional view taken along line XY of FIG. FIG. 3 is a plan view of a packaging bag for a microwave oven when a thin metal film is formed in a stripe shape in order to adjust the transmittance of microwaves. FIG. 4 is a plan view of the packaging bag for a microwave oven when three storage units having different microwave transmittances are provided. FIG. 5 is an explanatory diagram when the center seal portion that divides the storage portion A and the storage portion B of the microwave packaging bag is replaced with a weak center seal portion. 6 to 8 are explanatory diagrams when manufacturing the packaging bag for a microwave oven of the present invention. FIG. 9-
11 is an explanatory view when producing a packaging bag for a microwave oven according to Example 1, FIG. 12 is an explanatory view when producing a packaging bag for a microwave oven according to Example 2, and FIGS.
FIG. 9 is an explanatory diagram when a packaging bag for a microwave oven is manufactured according to the third embodiment.

As shown in FIG. 1, the packaging bag 1 for a microwave oven according to the present invention basically comprises two storage sections, a storage section (A) 18 and a storage section (B) 19. (A) 18
In order to process foods having different cooking times simultaneously in a microwave oven, a metal thin film 13 is laminated to make the microwave transmittance different from that of the storage section (B). In the packaging bag 1 for a microwave oven of the present invention, the inner surface layer is made of a heat-sealing resin, and as shown in FIG. 1, both sides and the lower part are formed with a side seal part 15 and a lower seal part 15a by heat sealing. The storage portion (A) 18 and the storage portion (B) 19 are divided by forming a center seal portion 16. Also, as shown in FIG.
The metal thin film 13 is laminated in the middle of the surface film 12 and the heat-sealing resin (hereinafter referred to as the heat-sealing layer 11) of the inner surface layer, and is placed in a microwave oven so that the metal thin film 13 does not come directly to the surface. The occurrence of sparks when a fire has occurred is prevented.

In FIG. 2, the metal thin film 13 is provided on both sides of the packaging bag 1 for a microwave oven, but when a packaging bag having a metal thin film provided on only one side is prepared and placed in a microwave oven,
When the metal thin film 13 is set on the upper side, transmission of microwaves is suppressed, and heating of the contents can be delayed.
When laminating a metal thin film on the microwave packaging bag of the present invention, in order to prevent the occurrence of sparks as described above, it is necessary to provide a metal thin film in the middle of the laminated material so as not to be exposed on the surface, In addition, it is necessary to prevent the metal thin film from being exposed on the end face of the laminated material. Therefore, in the present invention, as shown in FIG.
As shown by a dotted line in FIG. 18, the metal thin film 13 was not exposed on the end face of the packaging bag. Furthermore, metal thin film 1
In order to prevent the occurrence of sparks at the corners of No. 3, the corners were rounded.

As a method of forming a metal thin film, as shown in FIG. 3, the metal thin film 13 is formed in a stripe shape, and the amount of microwave transmission can be adjusted. That is, the metal thin film 13
Are formed in a striped pattern, and by changing the area of the metal thin film 13, the amount of microwave transmission from the storage section (A) 18 of the packaging bag is adjusted to adjust the heating time of the contents. It is. Even if the metal thin film 13 is not formed in a stripe shape,
Since the amount of microwave transmission can be adjusted by changing the area ratio of the metal thin film in the storage section (A), the shape of the metal thin film may be any shape such as a square, a circle, and an ellipse, and the shape is particularly limited. is not.

Further, a plurality of storage sections can be formed in the packaging bag for a microwave oven of the present invention, and the microwave transmittance of each storage section can be changed. For example, as shown in FIG. 4, a storage section (A) 18 in which the metal thin film is provided on almost the entire surface of the storage section, a storage section (Aa) 18a in which the metal thin film is formed in a stripe shape, and a storage section (B) having no metal thin film. ) 19, it is also possible to change the microwave transmittance of each storage section and simultaneously process three types of foods having different cooking times in a microwave oven.

As shown in FIG. 1, the packaging bag 1 for a microwave oven according to the present invention has a center seal portion 16 formed therein, and a storage portion (A) in which a metal thin film is laminated and a storage portion (B) made of a plastic film. When the packaging bag is processed by a microwave oven, the storage portion B is expanded by the vapor pressure of the contents, and the center seal portion 16 is broken by the vapor pressure. In some cases, the sealing strength is weakened to form a weakly sealed portion. That is, as shown in FIG. 5A, in the packaging bag 1 for a microwave oven of the present invention,
The center seal portion is formed to have a weaker heat seal strength than the side seal portion 15 and the lower seal portion 15a, thereby forming a weak center seal portion 17. Next, the microwave packaging bag 1
And the upper heat-sealed portion 15b is formed by a known method, thereby producing a sealed packaging bag 2 for a microwave oven as shown in FIG. 2 (b). The seal strength of the upper heat seal 15b is the same as that of the side seal 15 and the lower seal 15a.

The microwave packaging bag 1 having the weak center seal portion 17 is formed in, for example, a storage portion (A) (a metal thin film is formed on stripes so that microwaves can partially pass therethrough). When the sauce is put, the spaghetti is put in the storage section (B) to form and seal the upper seal portion 15b, and when this is heated in a microwave oven, the spaghetti is heated and the storage section (B) expands due to vapor pressure. At this time, the weak center seal portion 17 is broken by the expansion force, so that the source of the storage portion (A) 18 and the spaghetti of the storage portion (B) 19 can be mixed. Therefore, foods having different cooking times can be simultaneously processed in a microwave oven and mixed in the same bag to provide cooked foods.

Hereinafter, a method for producing the packaging bag for a microwave oven according to the present invention will be described. First, as shown in FIG. 6A, a base film 21 is laminated on a metal thin film 13 such as an aluminum foil or the like by extrusion coating with polyethylene (hereinafter referred to as PE), polypropylene (hereinafter referred to as PP) or the like. Also, PE film, PP
The films may be laminated by a dry lamination method using an adhesive. Next, an adhesive resin is coated on the metal thin film 13 side to form an adhesive layer 22, and a metal thin film laminated film 20 is produced.

Further, a PET film, a PP film, or the like is used as a base film, and an aluminum vapor deposition film is formed thereon by vacuum vapor deposition or the like to form a metal thin film 13, and an adhesive layer is formed on the metal thin film 13 (metal thin film 13). 22 can be formed into the metal thin film laminated film 20. In this case, the adhesive layer 22 can be formed by laminating PE or PP by an extrusion method.

Next, the metal thin film laminated film 20 is shown in FIG.
As shown in (b), the sheet is punched into a strip with rounded corners so as to fit the size of the microwave packaging bag. The punched strip-shaped metal thin film laminated film 20
As shown in FIG. 7A, an adhesive layer 2 is formed on a surface film 12 such as a PET film, a PP film, and a nylon film.
Adhesive through 2. Next, PE is laminated thereon by an extrusion method to produce a laminated film 3 having a heat seal layer 11 having a metal thin film as an intermediate layer, as shown in FIG. 7B. Heat seal layer 11
Can be formed by laminating a PE film or a PP film by a dry lamination method using an adhesive. This laminated film 3 is cut according to the size of the packaging bag for a microwave oven as shown in FIG. FIG. 7C is a diagram in which the heat seal layer 11 is exposed on the surface.

Next, the laminated film cut to the size of the packaging bag is folded into two from the broken line 23 with the heat seal layer 11 inside, and both sides and the lower part are heat sealed.
As shown in FIG. 8A, a packaging bag is manufactured by forming the side seal portion 15 and the lower seal portion 15a. When a bag is formed using a single laminated film as described above, a packaging bag can be formed without forming the lower seal portion 15a.
The lower seal part 15a may not be formed.

Side seal part 15 and lower seal part 15
The packaging bag formed with a is further formed with a center seal portion 16 by heat sealing as shown in FIG. 8B, and has a storage portion (A) 18 and a storage portion (B) 19 for a microwave oven. This is called packaging bag 1. The center seal portion 16
As described above, when the packaging bag for a microwave oven is heated in a microwave oven, the heat seal strength is reduced so that the center seal portion 16 is broken by the vapor pressure of the contents put in the storage section (B) 19. May form. As a method for weakening the sealing strength, a known method such as a heat sealing method in which the heat sealing temperature is lowered or a method in which a center seal portion is coated with an easy-peeling resin can be used.

As shown in FIG. 8B, the storage section (A) 1
Microwave packaging bag 1 having 8 and storage section (B) 19
As shown in FIG. 8 (c), the storage unit (A) 18 is filled with food that does not require relatively heating, and the storage unit (B) 19 is filled with food to be cooked. The upper sealing portion 15b is formed to form a sealed packaging bag 2 for a microwave oven. When the sealed packaging bag for a microwave oven 2 is placed in a microwave oven, microwaves are sufficiently transmitted through the storage section (B), so that the content food is cooked. On the other hand, since the metal thin film is laminated on the storage section (A), most of the microwave is reflected, and the microwave is only slightly transmitted from the portion where the metal thin film is not provided. Therefore, the food contained in the storage section (A) is heated almost without being heated. Also, as shown in FIG. 3A, if the storage portion (A) is formed of a metal thin film in a striped shape and the microwave transmittance is adjusted, the microwave is considerably applied to the storage portion (A) 18. Since the content is transmitted through and heated, the delivery part (A) 1
Even if foods with different cooking times are put in the storage section 8 and the storage section (B) 19, it is possible to simultaneously process and cook with a microwave oven.

As the metal thin film used in the present invention, metal foils of aluminum, iron, copper, stainless steel, gold, silver and the like can be used, but aluminum foil is preferred from the viewpoint of production cost and the like. Further, a vapor-deposited film obtained by vapor-depositing the above metal on a PET film, a PP film, a nylon film or the like can be used, and an aluminum-deposited film is preferable.

The resin having heat sealing properties used in the present invention includes polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer, polyester resin and the like. When the contents filled in the packaging bag for a microwave oven of the present invention are cooked in a microwave oven, the interior of the packaging bag may reach 100 ° C., and therefore, polypropylene having a heat resistance of 100 ° C. or more is preferable.

The surface film used in the present invention includes cellophane, stretched polypropylene, unstretched polypropylene, polyethylene terephthalate, polyethylene naphthalate, nylon, polystyrene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl chloride, and polyvinyl chloride. Examples include films of vinylidene, polymethylpentene, polyacrylonitrile, and the like. Furthermore,
A multi-layer laminated film of the above-mentioned various plastic films (a co-extruded film, a laminated film laminated with an adhesive), a laminated film of a plastic film and paper, and the like can be used. In particular, heat-resistant unstretched polypropylene, polyethylene terephthalate, nylon, ethylene-vinyl alcohol copolymer and the like are preferred.

[0025]

Hereinafter, the present invention will be described in more detail with reference to examples. (Example 1) First, as shown in FIG.
Aluminum foil (hereinafter referred to as Al foil) 13a and thickness 3
A 0μ PP film 21a is laminated by a dry lamination method using a polyester-based adhesive, and a polyester-based adhesive is further applied to the Al foil 13a side of the laminated film to form an adhesive layer 22 to form an Al foil laminated film. 20a was produced.

Next, the Al foil laminated film 20a is
As shown in (b), a rectangular piece having a length of 300 mm and a width of 60 mm was punched out with rounded corners.
The punched strip-shaped Al foil layer film 20a is
(C) As shown in FIG.
2a was bonded to one side via an adhesive layer 22 at an interval of 40 mm. Next, on the side of the PET film 12a to which the Al foil laminated film 20a was bonded, a 40 μm thick PP
The film 11a was laminated by a dry lamination method using a polyester-based adhesive to produce a laminated film 3 having an Al foil laminated film on one side as an intermediate layer as shown in FIG. 9 (d). That is, this laminated film 3 has a PET film / Al foil laminated film / P on one side.
The P film and the other side consist of PET film / PP film.

The laminated film 3 was cut into a size of 340 mm in length and 220 mm in width as shown in FIG. Next, the cut laminated film 3 is folded in two with the PP film 11a inside from the broken line 23, and both sides are heat-sealed to form a side seal portion 15 having a width of 7 mm, as shown in FIG. like,
It was a packaging bag having an opening 14 at the top. The heat sealing conditions were a temperature of 150 ° C., a pressure of 2 kg / cm ² , and a time of 2 seconds. Further, as shown in FIG. 10 (c), a center seal portion 16 having a width of 6 mm is formed at a position 87 mm from the left end of the packaging bag under the same conditions as the side seal portion to form a storage portion (A ) 18 and a packaging bag 1 for a microwave oven having a storage section (B) 19 were produced. At this time, the Al foil laminated film 20a in the storage portion (A) 18 was used.
Are 10 mm from the right end of the left side seal portion 15, 10 mm from the left end of the center seal portion, and the upper opening 14.
20 mm away from the storage unit, that is, 10 mm on the left side, 10 mm on the right side, and
mm without Al foil.

Next, as shown in FIG. 11 (a), 70 g of soup is filled into the storage portion (A) 18 of the packaging bag 1 for microwave oven from the opening 14 and 200 g of porridge is filled into the storage portion (B) 19, as shown in FIG. Then, as shown in FIG. 11 (b), the opening portion 14 was heat-sealed under the same conditions as the side seal portion to form an upper seal portion 15b to obtain a sealed packaging bag 1a for a microwave oven, which was frozen and stored. . As a result of heating the microwave packaging bag 1 containing the frozen porridge and the soup in a microwave oven, both were heated to a temperature of 90 ° C. or more after 5 minutes.

(Embodiment 2) As in Embodiment 1, FIG.
A packaging bag having a side seal portion as shown in FIG. The heat sealing conditions for the side seal part are as follows:
The temperature was 150 ° C., the pressure was 2 kg / cm ² , and the time was 2 seconds.
Next, as shown in FIG. 12B, the heat sealing condition was set at a temperature of 130 mm at a position 87 mm from the left end of the packaging bag.
At 6 ° C., a pressure of 2 kg / cm ² and a time of 2 seconds, a weak center seal portion 17 having a width of 6 mm was formed, and a packaging bag 1 for a microwave oven having a storage portion (A) 18 and a storage portion (B) 19 was produced. . Next, the storage section A of the packaging bag 1 for microwave oven
(A) 18 is filled with 70 g of meat sauce, and (B) 19 is filled with 200 g of spaghetti.
5b was formed and sealed to produce a sealed packaging bag 2 for a microwave oven as shown in FIG.

As a result of heating the packaging bag filled with the spaghetti and the meat sauce in a microwave oven, when the spaghetti is heated and the storage portion (B) 19 expands by vapor pressure, the weak center seal portion 17 is broken by the expansion force. As a result, the meat sauce in the storage section (A) 18 flowed into the spaghetti side and was mixed. However, since the side seal portion 15 and the upper seal portion 15b are firmly bonded, the bag did not break even if the spaghetti was sufficiently heated. for that reason,
The spaghetti and the meat sauce with different cooking conditions were heated in the same bag to cook the spaghetti with the meat sauce.

(Embodiment 3) As shown in FIG.
A 7 μm thick Al foil 13 a and a 30 μm thick L-LDPE film 21 b are laminated by a dry lamination method using a polyester adhesive, and a polyester adhesive is applied to the Al foil 13 a side of the laminated film. Then, an adhesive layer 22 was formed to produce an Al foil laminated film 20a. Next, the Al foil laminated film 20a was
As shown in (b), a rectangular piece having a length of 300 mm and a width of 60 mm was punched out with rounded corners.
The punched strip-shaped Al foil layer film 20a is
(C) As shown in FIG.
2a was bonded via an adhesive layer 22 at intervals of 40 mm. Next, on the side of the PET film 12a to which the Al foil laminated film 20a is adhered, L-LDPE is laminated to a thickness of 40 μm by an extrusion method to form an L-LDP.
An E film 11b was formed, and as shown in FIG. 13D, a laminated film 3 having an Al foil laminated film 20a on one side was produced.

The laminated film 3 was cut into a size of 330 mm in length and 210 mm in width as shown in FIG. Next, the cut laminated film 3 was folded in two with the L-LDPE film 11b inside from the fold line 23, and both sides were heat-sealed to form a side seal portion 15 having a width of 7 mm to obtain a packaging bag. The heat sealing conditions were a temperature of 125 ° C., a pressure of 2 kg / cm ² , and a time of 2 seconds. At this time, the left side seal portion 15 and A
The distance from the 1 foil was 5 mm. Further, as shown in FIG. 14C, a weak center seal portion 17 having a width of 6 mm is formed at a position 77 mm from the left end of the packaging bag, and the storage portion (A) 18 and the storage portion (B) 19 are formed. To prepare a packaging bag 1 for a microwave oven. The heat sealing conditions at this time are as follows:
The temperature was 115 ° C., the pressure was 1 kg / cm ² , and the time was 2 seconds.
The distance between the Al foil laminated film 20a and the weak center seal portion 17 was 5 mm.

Storage portion (A) of the above-mentioned microwave packaging bag 1
18 butter 40g, storage section (B) 19 potato 200
g, and the opening 14 is heat-sealed under the same conditions as the side seal portion to form an upper seal portion 15b.
2 (c) as a sealed packaging bag 2 for a microwave oven,
This was frozen and stored. The distance between the Al foil laminated film 20a of the sealed packaging bag 2 for a microwave oven, the side seal portion 15, the weak center seal portion 17, and the upper seal portion 15b was 5 mm.

As a result of heating the sealed packaging bag 2 for a microwave oven filled with the potatoes and butter in a microwave oven, when the potatoes are heated and the storage section B (B) 19 expands by vapor pressure, the expansion force is weak. The center seal portion 17 was torn and the butter of the storage portion (A) 18 flowed toward the storage portion (B) 19 and penetrated into the potatoes, so that the potatoes with butter could be cooked. Since the side seal portion 15 and the upper seal portion 15b were firmly bonded, the bag did not break even if the potatoes were sufficiently heated.

[0035]

According to the present invention, one packaging bag has a plurality of storage portions, and at least one of the storage portions is provided with a metal thin film layer made of an aluminum foil or an aluminum vapor-deposited film. Since the microwave transmittance is different from that of the other storage sections, foods having different cooking times can be simultaneously heated and cooked. In addition, since the microwave transmittance of the storage portion provided with the metal thin film layer can be controlled by changing the area ratio of the metal thin film layer (such as Al foil) in the storage portion, the heating time of the contents can be easily adjusted. can do. That is, when the storage unit is hardly heated, the Al foil is provided on the entire surface of the storage unit, and when the microwave transmittance of the storage unit is changed, the Al foil is formed in a stripe shape or a circular shape. Since only the size of the Al foil needs to be changed, the time required for cooking or heating the contents can be set relatively easily by experiment.

In the packaging bag for a microwave oven according to the present invention, the storage section having the metal thin film layer and the other storage section are divided by heat sealing, and the heat sealing section is separated from the other heat sealing sections (up and down of the packaging bag). (The seal portion and the side seal portion), the heat sealing strength is formed weaker, and after heating and cooking the contents of each storage portion, the weak heat seal portion can be broken to mix the two foods. For example, spaghetti and sauce are heated simultaneously in separate storage sections, and when spaghetti is completely heated and cooked and the storage section expands due to steam pressure, the weak heat seal portion is broken by the expansion force and the spaghetti and sauce are separated. It can also be possible to mix. Furthermore, the packaging bag for a microwave oven of the present invention is coated with a synthetic resin layer so that the end face of the aluminum foil is not exposed so that no spark is generated by lamination of the metal thin film layer (aluminum foil). Since the corners of the foil were rounded, the problem of the conventional microwave packaging bag using Al foil could be solved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a packaging bag for a microwave oven according to the present invention.

FIG. 2 is a cross-sectional view taken along line X-Y of FIG. 1, showing a layer configuration of the packaging bag for a microwave oven of the present invention.

FIG. 3 is a plan view of a packaging bag for a microwave oven when a metal thin film is formed in a stripe shape in order to adjust microwave transmittance.

FIG. 4 is a plan view of a packaging bag for a microwave oven when three storage units having different microwave transmittances are provided.

FIG. 5 is an explanatory diagram when the center seal portion that divides the storage portion A and the storage portion B of the microwave packaging bag is replaced with a weak center seal portion.

FIG. 6 is an explanatory view for producing a strip-shaped metal thin film laminated film used for a packaging bag for a microwave oven.

FIG. 7 is an explanatory diagram when a packaging bag for a microwave oven is made using a strip-shaped metal thin film laminated film.

FIG. 8 is an explanatory diagram for producing a packaging bag for a microwave oven having two storage units.

FIG. 9 is an explanatory diagram when a packaging bag for a microwave oven of the present invention is produced according to Example 1, and is a diagram when an Al foil laminated film and a laminated film using the same are produced.

FIG. 10 is an explanatory view when a packaging bag for a microwave oven is made from the laminated film according to the first embodiment.

FIG. 11 is an explanatory view when a sealed packaging bag for a microwave oven is prepared by filling contents into a packaging bag for a microwave oven according to the first embodiment.

FIG. 12 is an explanatory view when a packaging bag for a microwave oven of the present invention is made according to the second embodiment.

FIG. 13 is an explanatory diagram when a packaging bag for a microwave oven of the present invention is produced according to Example 3, and is a diagram when an Al foil laminated film and a laminated film using the same are produced.

FIG. 14 is an explanatory diagram when a packaging bag for a microwave oven is made from the laminated film according to the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packaging bag for microwave ovens 2 Sealing packaging bag for microwave ovens 3 Laminated film 11 Heat seal layer 11a PP film 11b L-LDPE film 12 Surface film 12a PET film 13 Metal thin film 13a Al foil 14 Opening 15 Side seal 15a Lower seal Part 15b Upper seal part 16 Center seal part 17 Weak center seal part 18 Storage part A 19 Storage part B 20 Metal thin film laminated film 20a Al foil laminated film 21 Base film 21a PP film 21b L-LDPE film 22 Adhesive layer 23 Folding line

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 3E064 AA05 BA16 BA24 BA36 BA55 BB03 BC01 BC02 BC04 BC05 BC08 BC18 EA30 FA01 FA03 HN05 HT07 4F100 AB10A AB33A AK01B AK01C AK07 AK41 AK41G BA02 BA03 BA07 CB00 EDB12 DB12

Claims (5)

[Claims] 1. A packaging bag having a plurality of storage sections,
A packaging bag for a microwave oven, characterized in that a metal thin film is provided in at least one storage section so that the microwave transmittance is different from that of the other storage sections. 2. The packaging bag according to claim 1, wherein the metal thin film is made of an aluminum foil or an aluminum vapor-deposited film, the inner surface layer is made of a resin having heat sealing properties, and each of the storage sections is divided by heat sealing. The packaging bag for a microwave oven according to claim 1, wherein 3. The heat sealing part, which divides the storage part having the metal thin film and another storage part, has a lower heat sealing strength than other heat seal parts of the packaging bag. The packaging bag for a microwave oven according to claim 1 or 2. 4. The packaging bag for a microwave oven according to claim 1, wherein an end face of said metal thin film is covered with a synthetic resin layer. 5. The packaging bag for a microwave oven according to claim 1, wherein a corner portion of the metal thin film is formed in a round shape.