TW201718368A - Package - Google Patents

Abstract

A package comprises: a packaging container having a containing section open at the top and formed by a bottom and by a peripheral wall rising from the peripheral edge of the bottom, the packaging container further having a flange formed thereon, the flange being provided along the entire circumference of the peripheral wall and protruding outward relative to the containing section from the upper end of the peripheral wall; a contained object contained within the containing section and producing vapor when heated; and a top seal joined to the flange along the entire circumference thereof to seal the inside of the containing section. The packaging container has a curved section where a part of the peripheral wall is curved toward the containing section. A maximum deformation point is formed in the curved section, the maximum deformation point being the point where the deformation of the peripheral wall is maximum when pressure within the containing section increases to deform the top seal. The deformed top seal and the flange are pulled in the direction in which the deformed top seal and the flange are separated from each other, and when pressure within the containing section exceeds a set value, the top seal is separated from the flange at the maximum deformation point to release vapor within the containing section.

Description

Package

The present invention relates to a package, and more particularly to a package containing a stored object which generates steam when heated by a microwave oven.

In such a package, the packaged food or the like is stored in the packaging container, and the packaging container is sealed in order to prevent entry of dust or the like. Such a package is sometimes heated in a microwave oven in order to heat the contents.

For example, Patent Document 1 discloses a container for packaging in a shallow dish shape sealed by a top seal.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2014-239661

However, the packaging container as shown in Patent Document 1 is After being sealed, if it is heated as it is, the pressure inside the product will continue to rise and the package will be broken. Thus, the food of the contents will be scattered and the inside of the microwave oven will be contaminated. In order to avoid such a situation, it is necessary to partially peel off one of the top seals before heating to make a state in which the vent holes are opened. For this reason, the top seal of the packaging container of Patent Document 1 is provided with a grip portion for peeling off, and a part of the top seal member must be peeled off from the grip portion, so that labor and time are problematic.

The present invention has been developed in order to eliminate such conventional problems, and an object thereof is to provide a package which can heat and condition a contained object without peeling off a part of the top seal before being heated by a microwave oven.

The package according to the present invention is heated by a microwave oven and includes a packaging container having a receiving portion formed by a bottom portion and a peripheral wall portion standing from the periphery of the bottom portion and having an upper portion open, and formed over the entire circumference of the peripheral wall portion. a flange portion protruding outward from the upper end of the peripheral wall portion with respect to the receiving portion; the stored object being received in the housing portion and being heated to generate steam; and a top seal member extending over the entire circumference of the flange portion The packaging container is joined to the flange portion to seal the inside of the accommodating portion; and the packaging container has a curved portion in which one of the peripheral wall portions is bent toward the accommodating portion, and when the internal pressure of the accommodating portion is increased and the top sealing member is deformed, the deformation amount of the circumferential wall portion is the largest. The maximum point is formed in the curved portion; when heated by the microwave oven, the vapor generated by the stored object or The expansion of the gas caused by the warming, the internal pressure of the accommodating portion is increased, and the bending angle formed between the packaging container and the top seal is deformed, and the portion of the top seal that is at the maximum deformation point is joined to the flange portion of the packaging container. The buckling angle of the peripheral wall portion other than the maximum deformation amount is large, and the deformed top seal and the flange portion are stretched in a direction away from each other, and if the internal pressure of the accommodating portion exceeds the set value, the deformation amount is the largest. At the point, the top seal is peeled off from the flange portion and the vapor in the housing portion is discharged.

Further, it is preferable that the upper end of the peripheral wall portion has a pair facing each other, and the packaging container has a curved portion on each of the pair of sides.

In this case, it is preferable that the upper end of the peripheral wall portion has a substantially rectangular shape, and the packaging container has a curved portion on one of the long sides of the rectangular shape.

The packaging container may have a handle portion formed on a peripheral wall portion other than the curved portion.

Further, it is possible that the flange portion has a joint convex portion that protrudes toward the opposite side of the bottom portion and extends over the entire circumference of the flange portion, and the top seal is joined to the joint convex portion.

Further, it is preferable that the top seal is joined to the flange portion so as to have substantially the same joint width over the entire circumference of the flange portion.

The object to be stored may be a food or a frozen food. Further, the packaging container may be formed of resin or paper.

Further, the present invention can also constitute a packaging container for such a package.

According to the invention, the packaging container has a curved portion in which one of the peripheral wall portions is bent toward the accommodating portion, and the amount of deformation of the peripheral wall portion is the largest when the tension from the top seal deformed by the internal pressure of the accommodating portion is received. The maximum point is formed in the curved portion; when heated by the microwave oven, the flange portion is stretched from the top seal deformed by the vapor generated by the stored object so that the internal pressure of the accommodating portion rises; if the internal pressure of the accommodating portion exceeds the setting When the value is the largest, the top seal is peeled off from the flange portion and the vapor in the accommodating portion is discharged. Therefore, the package which can be heated and conditioned by the contents can be removed without peeling off a part of the top seal before heating in the microwave oven.

11, 32, 42, 52‧‧‧ Packaging containers

12‧‧‧ bottom

13‧‧‧Walls

14‧‧‧ Housing Department

15‧‧‧Front Department

16‧‧‧Hands

17, 18‧‧ ‧ step department

19, 31, 41, 51‧‧‧ package

20‧‧‧Acolates

21‧‧‧Top seal

22‧‧‧Joint projections

C‧‧‧Bend

M‧‧‧ the largest amount of deformation

Θ0, θ1, θ2‧‧‧ buckling angle

P‧‧‧ internal pressure

Fv1, Fv2‧‧‧

D1‧‧‧1st direction

D2‧‧‧2nd direction

L1‧‧‧1st central axis

L2‧‧‧2nd central axis

Fig. 1 is a plan view showing a packaging container used for a package according to Embodiment 1 of the present invention.

Fig. 2 is a front view showing the packaging container.

Figure 3 is a side view showing the packaging container.

Fig. 4 is a plan view showing a package body according to the first embodiment.

Fig. 5 is a front cross-sectional view of the package taken along the center line L1 of Fig. 4.

Fig. 6 is a side cross-sectional view of the package body taken along the center line L2 of Fig. 4.

Fig. 7 is a partial enlarged view of the special drawing of Fig. 5.

Figure 8 shows the results of a one-quarter model simulation of the package. Figure.

Fig. 9 is a front cross-sectional view showing a state in which the package according to the first embodiment is heated.

Fig. 10 is a side cross-sectional view showing a state in which the package according to the first embodiment is heated.

Figure 11 is a partial enlarged view of the special drawing of Figure 9.

Figure 12 is a partial enlarged view of the special drawing of Figure 10.

Fig. 13 is a plan view showing a package body according to the second embodiment.

Fig. 14 is a plan view showing a package body according to the third embodiment.

Fig. 15 is a plan view showing a package body according to the fourth embodiment.

Fig. 16 is an enlarged cross-sectional view showing a specific portion of the engaging convex portion.

Hereinafter, Embodiment 1 of the present invention will be described based on the drawings.

Fig. 1 is a plan view showing a packaging container 11 used for a package according to Embodiment 1 of the present invention. The packaging container 11 has a substantially rectangular outer shape as viewed from above, and has a first central axis L1 extending in the first direction D1 parallel to the long side of the rectangular shape, and a second parallel to the short side of the rectangular shape. The second central axis L2 extending in the direction D2 is also symmetrical.

The packaging container 11 has a substantially rectangular bottom portion 12, and a peripheral wall portion 13 is formed on the periphery of the bottom portion 12. The peripheral wall portion 13 is erected from the periphery of the bottom portion 12 as shown in Figs. 2 and 3 . The peripheral wall portion 13 surrounds the bottom Above the portion 12, as shown in Fig. 1, the upper portion of the accommodating portion 14 is formed.

Among the peripheral wall portions 13, the peripheral wall portion 13 of the portion corresponding to one of the long sides of the rectangle extending in the first direction D1 is formed as a curved portion C that is bent toward the accommodating portion 14.

A flange portion 15 that protrudes from the upper end of the peripheral wall portion 13 toward the outside of the accommodating portion 14 is formed over the entire circumference of the peripheral wall portion 13. The flange portion 15 formed at the upper end of the peripheral wall portion 13 of the portion extending in the second direction D2 of the peripheral wall portion 13 has a handle portion 16 formed to protrude outward, and the handle portion 16 and the flange portion 15 are formed. Connected to each other.

Here, since the curved portion C is bent toward the accommodating portion 14, the flange portion 15 formed at the upper end of the curved portion C is bent toward the accommodating portion 14 among the flange portions 15.

Further, a step portion 17 is formed on the bottom portion 12, and a plurality of step portions 18 are formed on the bottom portion 12 and the curved portion C. The step portion 17 and the plurality of step portions 18 are used to reinforce the strength of the packaging container 11, and are formed by setting a step difference between one of the bottom portion 12 and the curved portion C.

Such a packaging container 11 can be formed of resin or paper.

Fig. 4 is a plan view showing the package 19 according to the first embodiment in which the packaging container 11 is used. The packaged body 19 is formed by accommodating the accommodated product 20 in the accommodating portion 14 of the packaging container 11 and sealing the accommodating portion 14 with a top seal formed of a resin film. Moreover, in order to make the object 20 observable, in the fourth The top seal is omitted from the figure. Further, the package 19 is heated by a microwave oven, and the stored object 20 is vaporized by an increase in temperature due to heating.

Fig. 5 is a front cross-sectional view showing the package 19 shown in Fig. 4 taken along the first central axis L1, and Fig. 6 is a view showing the package 19 shown in Fig. 4 cut along the second central axis L2. A side cutaway view.

As shown in FIGS. 5 and 6 , the top seal 21 is disposed so that the stored object 20 is housed in the accommodating portion 14 and covers the accommodating portion 14 and the object 20 .

Further, in Fig. 5, the peripheral wall portion 13 of the portion of the peripheral wall portion 13 shown in Fig. 4 that overlaps with the first central axis L1 is shown. Further, in Fig. 6, the peripheral wall portion 13 of the portion of the peripheral wall portion 13 shown in Fig. 4 that overlaps with the second central axis L2 is shown. Specifically, the peripheral wall portion 13 of the portion overlapping the second central axis L2 forms the curved portion C.

Further, the top seal 21 is joined to the entire circumference of the flange portion 15, so that the accommodating portion 14 is sealed by the top seal 21. At this time, the top seals 21 are joined so as to have substantially the same joint strength throughout the entire circumference of the flange portion 15.

Fig. 7 is an enlarged view showing the vicinity of the flange portion 15 of Fig. 5. As shown in FIGS. 5 and 6, the top seal 21 is joined over the entire circumference of the flange portion 15 with a certain tension.

Fig. 8 is a view showing a result of a one-fifth model simulation for confirming the effect of stress on the package 19 when the internal pressure of the accommodating portion 14 sealed by the top seal 21 is increased. And caused deformation. For the package 19 shown in FIG. 4, as shown in FIG. 8, a model of one-fourth of the package 19 divided by one of the first central axis L1 and the second central axis L2 is used. simulation. However, the object 20 is omitted in the simulation. Further, in the simulation, for each of the first central axis L1 and the second central axis L2, the split surface is assumed to be a free end that is not open. Since the shape of the package 19 is symmetrical with respect to the first central axis L1 and symmetrical with respect to the second central axis L2, the simulation result for the package 19 divided into one quarter can be applied to the undivided package 19.

In the eighth drawing, the shape of the packaging container 11 before the internal pressure of the accommodating portion 14 is raised is indicated by a one-dot chain line, and the shape after the internal pressure of the accommodating portion 14 is raised is indicated by a solid line.

As a result of the simulation, it was found that the top seal 21 was deformed to expand upward by the internal pressure of the accommodating portion 14 sealed by the top seal 21, and the peripheral wall portion 13 was also deformed. The cause of this is considered to be that the self-deformed top seal 21 receives the tensile force over the entire circumference of the flange portion 15, and the internal pressure of the raised accommodating portion 1 acts on the entire peripheral wall portion 13.

When the internal pressure of the accommodating portion 14 rises, the curved portion C and the peripheral wall portion 13 other than the curved portion C are deformed so as to be conventionally attached to the accommodating portion 14, and the amount of deformation of the curved portion C is more deformed than the peripheral wall portion 13 other than the curved portion C. The amount is large. This fact shows that the curved portion C is more easily deformed than the peripheral wall portion 13 other than the curved portion C. Further, it is understood that the maximum deformation point M at which the amount of deformation in the peripheral wall portion 13 is the largest is formed in the curved portion C. Moreover, the maximum amount of deformation M is at the boundary portion between the top seal 21 and the flange portion 15. The middle portion is a portion where the curved portion C shown in Fig. 4 overlaps with the second central axis L2. Further, it is also apparent that the stress is concentrated on the maximum point M of the deformation amount, and the flange portion 15 having the largest deformation point M is more powerful than the other flange portion 15.

When the package 19 shown in FIG. 4 is heated in a microwave oven, steam is generated from the stored product 20 due to an increase in the temperature of the stored article 20 accommodated in the accommodating portion 14. At this time, since the accommodating portion 14 is sealed by the joining of the top seal 21 toward the flange portion 15, the steam is generated from the object 20 and heated by the temperature rise of the object 20 to be stored. The gas in the accommodating portion 14 expands, and the internal pressure of the accommodating portion 14 gradually rises.

As shown in FIGS. 9 and 10, the top seal 21 is deformed so as to expand upward above the accommodating portion 14 as the internal pressure P of the accommodating portion 14 rises. Further, the rising internal pressure P uniformly acts on the entire peripheral wall portion 13, whereby the peripheral wall portion 13 is deformed toward the accommodating portion 14.

As a result of the simulation of the package 19 described above, as shown in Fig. 8, among the peripheral wall portions 13 that are equally subjected to the force, the maximum deformation point M at which the amount of deformation is the largest is formed in the curved portion C.

Therefore, as shown in Figs. 9 and 10, the peripheral wall portion 13 which is deformed by the tensile force from the top seal 21 and the increased internal pressure P is the same as the result of the simulation, and the curved portion C is the same as that of the simulation. The peripheral wall portion 13 other than the curved portion C is more deformed. Further, as shown in Fig. 10, the maximum deformation point M at which the amount of deformation of the peripheral wall portion 13 is the largest is formed in the curved portion C.

Further, since the maximum amount M of the deformation amount is the same as the result of the simulation, it is formed in the curved portion C that overlaps with the second central axis L2 shown in FIG. 4, Therefore, as shown in Fig. 10, the maximum amount of deformation M of the pair is formed by sandwiching the accommodating portion 14, respectively.

As shown in Fig. 7, before the heating of the package body 19, the portion of the top seal member 21 that is joined to the flange portion 15 extends unbuckling relative to the flange portion 15. By heating the package 19, the top seal 21 is deformed, and the entire circumference of the peripheral wall portion 13 is deformed toward the accommodating portion 14, so that the portion of the top seal 21 that is joined from the flange portion 15 is opposed to the flange portion 15 Buckling in a manner that has a specific flexion angle.

Fig. 11 is an enlarged view showing the vicinity of the flange portion 15 of Fig. 9. In the cross section in which the deformed package 19 is cut at the position of the first central axis L1, the deformed top seal 21 has a portion from the flange portion 15 with respect to the flange portion 15 to have a flexion angle θ1. Way to flex.

Fig. 12 is an enlarged view showing the vicinity of the flange portion 15 of Fig. 10. In the cross section of the packaged body 19 which is deformed at the position of the second central axis L2, the deformed top seal 21 has a portion from the flange portion 15 with respect to the flange portion 15 to have a flexion angle θ2. Way to flex.

At this time, the deformation amount of the maximum deformation point M is larger than the peripheral wall portion 13 other than the maximum deformation point M. Therefore, the flexion angle θ2 shown in Fig. 12 is larger than the flexion angle θ1 shown in Fig. 11 . .

Further, since the bending angle of the top seal 21 is increased, the tensile force of the flange portion 15 from the top seal 21 is increased, and the component force perpendicular to the flange portion 15 is increased.

As shown in Fig. 11, the flange portion 15 is heavier than the first central axis L1. The flange portion 15 of the stacked portion receives a component force Fv1 perpendicular to the flange portion 15. Further, as shown in Fig. 12, the flange portion 15 of the portion of the flange portion 15 that overlaps with the second central axis L2, that is, the flange portion 15 having the largest deformation point M, is opposed to the flange portion 15 Vertical component Fv2.

As described above, the flexion angle θ2 shown in Fig. 12 is larger than the flexion angle θ1 shown in Fig. 11, and therefore the component force Fv2 shown in Fig. 12 is larger than the component force Fv1 shown in Fig. 11 .

As the internal pressure of the accommodating portion 14 rises, the amount of deformation of the top seal 21 and the amount of deformation of the peripheral wall portion 13 become larger, and the buckling angle of the top seal 21 also becomes larger. Further, since the tension of the top seal 21 is also increased, the component force perpendicular to the flange portion 15 becomes large. This component force acts on the peeling of the top seal 21, and the top seal 21 is peeled off from the flange portion 15 upon reaching a specific peeling force.

As shown in FIGS. 9 and 10, if the internal pressure P of the accommodating portion 14 continues to rise, the amount of deformation of the top seal 21 and the amount of deformation of the peripheral wall portion 13 also become large. At this time, as in the result of the simulation, the amount of deformation of the maximum point M of the deformation amount in the peripheral wall portion 13 becomes larger, and the bending angle θ2 shown in Fig. 12 also becomes larger. Further, since the tension of the top seal 21 is also increased, the vertical component force Fv2 of the opposite edge portion 15 of the maximum amount of deformation M will continue to approach a specific peeling force.

Thus, the internal pressure P of the accommodating portion 14 exceeds the set value, and the component force Fv2 of the tensile force of the top seal 21 of the maximum point M to be deformed reaches a specific peeling force, and a part of the top seal 21 is the maximum amount of self-deformation. The flange portion 15 of the M is peeled off, so that the vapor is discharged from the accommodating portion 14. Further, although one of the packaging containers 11 forms a maximum point M of deformation in each of the curved portions C, the shape and strength due to manufacturing tolerances of the packaging container 11 are not uniform and the top seal 21 is directed to the flange portion. The unevenness of the joint strength of 15 and the one of the maximum deformation points M of the pair will start the peeling of the top seal 21 first. Then, if the vapor is discharged between the top seal 21 and the flange portion 15 from the peeling, the internal pressure P of the accommodating portion 14 is drastically lowered.

In the prior package, since the packaging container is sealed, one of the top seals must be partially peeled off to form a vented opening before heating, and then the package is heated in a microwave oven. To this end, one of the top seals must be partially peeled off from the grip provided by the top seal, resulting in labor and time.

On the other hand, in the package 19 according to the first embodiment, even if the package 19 is heated in a microwave oven in a state where the accommodating portion 14 is sealed, the internal pressure of the accommodating portion 14 rises beyond a set value, and the top seal 21 will The peeling is automatically performed so that the internal pressure of the accommodating portion 14 is lowered. Therefore, the internal pressure of the accommodating portion 14 does not continue to rise to the extent that the stored object 20 scatters in the oven of the microwave oven, and there is no concern of soiling in the oven of the microwave oven. Therefore, the container 20 can be heated and conditioned by the labor and time required to partially peel off the top seal 21 before it is heated.

Further, the stored article 20 is heated and adjusted to a portion of the top seal 21 to be automatically peeled off when the accommodating portion 14 is sealed. When the accommodating portion 14 is sealed, the vapor containing heat energy is not unnecessarily released to the outside of the package 19, and can be pressurized at a pressure of more than atmospheric pressure in a state where the vapor is full. Heat conditioning allows the time required for heat conditioning to be reduced.

Embodiment 2

Fig. 13 shows a package 31 according to the second embodiment. In the first embodiment, the curved portion C is formed on each of the pair of long sides of the substantially rectangular shape formed at the upper end of the peripheral wall portion 13 of the packaging container 11, but the curved portion C is not necessarily formed on each of the pair of long sides. Specifically, as shown in FIG. 13, the curved portion C may be formed on any one of the long sides of the substantially rectangular shape formed at the upper end of the peripheral wall portion 13 of the packaging container 32.

In this case as well, in the same manner as in the first embodiment, when the package 31 is heated in a microwave oven, the flange portion 15 having the largest amount of deformation formed in the curved portion C is automatically peeled off, so that the top seal can be automatically peeled off. The labor and time to peel off one of the top seals before heating will be heated and conditioned by the contents 20.

Embodiment 3

Fig. 14 shows a package 41 according to the third embodiment. In the first embodiment, the upper end of the peripheral wall portion 13 of the packaging container 11 is formed substantially in a rectangular shape. However, it is not always necessary to have the peripheral wall portion 13 extending in the second direction D2 of the peripheral wall portion 13 projecting inward. In other words, as shown in Fig. 14, the peripheral wall portion 13 of the peripheral wall portion 13 of the packaging container 42 that extends in the second direction D2 may be curved so as to protrude outward.

The upper end of the peripheral wall portion 13 of the packaging container 42 can form a closed pattern, and the upper end of the peripheral wall portion 13 has a direction extending in the first direction D1. One of the opposite sides forms a curved portion C on each of the pair of sides.

By forming the curved portion C in the packaging container 42 in this manner, it is the same as the first and second embodiments, so that the package 41 can be used in a microwave oven without causing a part of the top seal to be peeled off before heating. The object 20 is heated and conditioned by heating.

Embodiment 4

Fig. 15 shows a package 51 according to the fourth embodiment. In the first to third embodiments, the upper ends of the peripheral wall portions 13 of the packaging containers 11, 32, 42 have opposite sides facing each other, but as shown in Fig. 15, the packaging container 52 may have a circular shape when viewed from above. Or an oval shape.

The curved portion C can be formed by bending the peripheral wall portion 13 of a portion of the peripheral wall portion 13 of the packaging container 52 to the accommodating portion 14 in the past.

As described above, even if the packaging container 52 has a circular or elliptical shape as viewed from above, by forming the curved portion C, it is possible to form a curved portion C, and it is possible to prevent partial peeling of the top sealing member before heating. Under the labor and time, the package 51 is heated by a microwave oven to heat and regulate the contained object 20.

Further, as shown in Fig. 16, the flange portions 15 of the packaging containers 11, 32, 42, 52 which are used in the packages 19, 31, 41, and 51 of the first to fourth embodiments are provided toward the bottom portion 12 The joining convex portion 22 that protrudes on the opposite side and extends over the entire circumference of the flange portion 15 and joins the top seal 21 to the joining convex portion 22.

Further, the top seal 21 and the flange portion 15 are joined to each other so as to be substantially the same throughout the entire circumference of the flange portion 15. However, if the top seal member 21 has substantially the same joint strength, the joint width is not necessarily the same. Roughly the same. Moreover, if sufficient joint strength can be ensured over the entire circumference of the flange portion 15, the joint between the top seal 21 and the flange portion 15 of the curved portion C can be made wider than the peripheral wall portion 13 other than the curved portion C. The joint width of the flange portion 15 is narrow.

Further, the joining of the top seal 21 can be carried out by a conventional method, for example, by using an adhesive, or by heat sealing. Further, in the first to fourth embodiments, the packaging containers 11, 32, 42, 52 and the top sealing member 21 are formed of a resin film, but the material may be joined as long as the bonding is not performed. The escaping person may be, for example, a paper product formed by laminating a resin.

Further, the handle portions 16 of the packaging containers 11, 32, and 42 used in the packages 19, 31, and 41 of the first to third embodiments are not necessarily required to be integrally connected to the flange portions 15, and may be integrated. The peripheral wall portion 13 formed outside the curved portion C. Further, the packaging containers 11, 32, and 42 in the first to third embodiments may be configured not to have the handle portion 16.

In addition, in the first to fourth embodiments, instead of the food to be contained 20 which is the food to be conditioned, various foods such as foods and frozen foods which have not been conditioned may be used to generate steam by heating.

11‧‧‧Packaging container

13‧‧‧Walls

14‧‧‧ Housing Department

15‧‧‧Front Department

16‧‧‧Hands

19‧‧‧Package

20‧‧‧Acolates

C‧‧‧Bend

Claims (10)

A package body which is heated by a microwave oven, wherein the package body comprises: a packaging container having a receiving portion formed by a bottom portion and a peripheral wall portion standing from a periphery of the bottom portion and having an upper portion open, and extending over the peripheral wall a flange portion that protrudes outward from the upper end portion of the peripheral wall portion with respect to the housing portion, and a stored object that is accommodated in the housing portion and is heated to generate steam; and a top seal member The inside of the accommodating portion is sealed by being joined to the flange portion over the entire circumference of the flange portion. The packaging container has a curved portion in which one of the peripheral wall portions is bent toward the accommodating portion, and the internal pressure of the accommodating portion rises. When the top seal is deformed, the maximum amount of deformation of the peripheral wall portion is formed in the curved portion; and when the microwave is heated by the microwave oven, the gas generated by the stored object or the heated gas is heated. Expanding, the internal pressure of the accommodating portion is increased, and the packaging container and the top seal are deformed, and the amount of deformation is before the maximum point The buckling angle formed between the portion where the top seal is joined to the flange portion of the packaging container is larger than the buckling angle of the peripheral wall portion other than the maximum amount of deformation, and the top seal is deformed as described above The flange portion is stretched in a direction away from each other, and when the internal pressure of the accommodating portion exceeds a set value, the top seal is peeled off from the flange portion and the vapor in the accommodating portion is discharged at a point at which the deformation amount is maximum . The package according to claim 1, wherein the upper end of the peripheral wall portion has a pair facing each other, and the packaging container has the curved portion on each of the pair of sides. The package according to claim 2, wherein the upper end of the peripheral wall portion has a substantially rectangular shape, and the packaging container has the curved portion on one of the long sides of the rectangular shape. The package according to any one of claims 1 to 3, wherein the packaging container has a handle portion formed on the peripheral wall portion other than the curved portion. The package according to any one of claims 1 to 3, wherein the flange portion has a joint projection projecting toward the opposite side of the bottom portion and extending over the entire circumference of the flange portion, the top seal The piece is joined to the aforementioned engaging projection. The package according to any one of claims 1 to 3, wherein the top seal is joined to the flange portion so as to have substantially the same joint width over the entire circumference of the flange portion. The package according to any one of claims 1 to 3, wherein the object to be contained is a food. The package of claim 7, wherein the food product is a frozen food. The package according to any one of claims 1 to 3, wherein the container for packaging is formed of resin or paper. A packaging container for use in a package according to any one of claims 1 to 9.