JP4347407B2 - Packaging and containers - Google Patents

Description

  The present invention relates to a package that can release gas generated from the contents to the outside of the container, and a container used for the package.

  Foods such as lunch boxes and side dishes are often sold in the form of a package sealed inside a resin container in order to prevent foreign substances from entering or prevent deterioration in quality. Among these foods, there are many foods that can be cooked with a microwave oven or the like in a package. However, when the food is heated in a state of being sealed inside the container, there is a risk that the container may swell and burst due to water vapor generated from the food. Moreover, since fermented foods, such as kimchi, generate | occur | produce a carbon dioxide gas with progress of fermentation, there existed a possibility that a container may burst even if it does not heat a container. In view of this situation, in recent years, containers have been developed that can discharge water vapor or carbon dioxide generated from the contents to the outside.

  For example, Patent Document 1 includes a flexible container having a through hole in at least one place, and a sheet-like pressure regulating valve bonded so as to close the through hole. The automatic cooking package is characterized in that the sheet-like pressure regulating valve is opened when the pressure becomes a certain value or more. However, in the automatic cooking package of Patent Document 1, in order to provide the sheet-like pressure regulating valve, it was necessary to stick a flexible sheet formed separately from the flexible container to the flexible container. . For this reason, the package for automatic cooking of patent document 1 had the fault that a manufacturing process becomes complicated easily and manufacturing cost becomes high.

  Further, in Patent Document 2, a through-hole is provided in the lid body, a band seal is wound around the container body and the lid body to close the through-hole, and when heating with a microwave oven or the like, due to an increase in internal pressure, A packaging container is described in which the band seal around the through-hole is pushed up. However, since the packaging container of Patent Document 2 needs to wrap the bandage around the container body and the lid, not only does the manufacturing cost increase, but the opening operation becomes cumbersome because the bandage has to be removed. Had drawbacks.

  Further, Patent Document 3 includes a container provided with a protrusion inside, a cooked food housed inside the container, and a resin film thermally welded to the upper end of the side wall of the container, and the top surface of the protrusion The food in a packaging container in which a through-hole is provided through the front and back and the through-hole is covered with the resin film is described.

  Furthermore, Patent Document 4 is a package that is sealed by adhering the lower surface of the resin film to the upper edge of the opening of the container body containing the contents, and has a through hole in the container wall of the container body, An annular convex portion is formed at the upper edge of the through hole, the upper surface of the convex portion and the lower surface of the resin film are brought into close contact with each other, and the gas generated from the contents is discharged from the through hole to the outside. A package is provided that allows for this.

  The food contained in the packaging container of Patent Literature 3 and the packaging body of Patent Literature 4 are capable of releasing gas generated from the contents from the through-holes provided in the container, despite having a relatively simple structure. However, it still had the following drawbacks. That is, the food contained in the packaging container of Patent Document 3 and the package of Patent Document 4 tend to stay in the local gas flow generated inside the container. It was easy to occur. This temperature difference may cause uneven heating in the contents, and may cause a decrease in the taste of the cooked food.

  In addition, the food contained in the packaging container of Patent Document 3 and the package of Patent Document 4 tend to be in a state in which the internal pressure of the container is lower than the external pressure after the gas inside the container is released from the through-hole, There was a risk of dents inside. These problems are not limited to the food in the packaging container of Patent Document 3 and the packaging body of Patent Document 4, but are also solved in other packaging bodies such as the automatic cooking package of Patent Document 1 and the packaging container of Patent Document 2. Absent.

JP-A-6-329179 JP 2000-344267 A Japanese Utility Model Publication No. 3-60279 JP 2003-221078 A

  The present invention has been made in order to solve the above-described problems. In addition to realizing a package that can release gas generated from the contents to the outside of the container with a simple structure, the present invention is provided on the container wall. When a gas is discharged from a through-hole, a package that can generate a gas flow in the entire interior of the container and heat the contents uniformly is provided. It is also an object of the present invention to provide a package that does not easily dent inside even after the gas inside the container has been released from the through hole. Furthermore, it is also an object of the present invention to provide a container that can be suitably used to configure the package.

  The above-mentioned problem is a package that seals the contents contained in the container by adhering the lower surface of the resin film to the first adhesive portion provided in an annular shape along the upper edge of the container. A first protruding portion that protrudes into the container and contacts the lower surface of the resin film is formed, and a through hole that penetrates the container wall on the upper surface of the first protruding portion and a portion surrounding the through hole are weakened on the lower surface of the resin film An annular second adhesive portion for bonding and a second protruding portion protruding higher than the upper edge of the second adhesive portion are provided, and when the internal pressure of the container increases, the resin film swells upward The problem is solved by providing a packaging body in which the second adhesive portion is peeled off and the gas inside the container is released to the outside of the container through the through hole.

  Thereby, the flow of the gas generated inside the container when the gas is released from the through hole provided in the container wall can be controlled by the second protrusion. Therefore, it is possible to cause a gas flow to occur in the entire interior of the container, and not only can the contents be heated uniformly, but also the gas can be efficiently released from the interior of the container. In addition, when the resin film swelled upward due to the internal pressure of the container returns to the original state, the resin film can be temporarily supported by the second protrusion, and the gas outside the container is brought into the container. Natural inflow will be possible. Therefore, it is possible to prevent the container from being recessed inward after the gas inside the container is released from the through hole.

  Here, “weakly” in the “second adhesive portion for weakly adhering to the lower surface of the resin film” means that the adhesive strength of the resin film in the second adhesive portion is lower than the adhesive strength of the resin film in the first adhesive portion. It shows that. In this way, when the resin film is weakly bonded at the second bonding portion, normally, when the internal pressure of the container is increased by heating the package while maintaining the airtightness inside the container. Makes it possible to peel off only the second adhesive part. In the first bonding portion, the resin film is usually bonded with an adhesive strength that cannot be removed unless it is intentionally peeled off by human hands.

  In the packaging body, the position where the through hole is provided is not particularly limited, but it is preferably provided at a position 5 mm or more away from the upper edge (outer edge) of the container toward the center. Since the package is generally carried around the upper edge (outer edge) of the container, if the through hole is close to the upper edge (outer edge) of the container, This is because the hot air emitted from the through hole may be easily touched with the finger.

  The position at which the second protrusion is provided is not particularly limited, but it is preferable that the second protrusion is disposed on the container center side when viewed from the through hole. As a result, the gas present at the center inside the container can reach the through hole after bypassing the second protrusion, and the temperature inside the container can be kept more uniform. The distance from the through hole to the second protrusion is not particularly limited, but if the through hole and the second protrusion are too far apart, it may be difficult to control the flow of gas reaching the through hole. For this reason, a 2nd protrusion part is normally distribute | arranged to the area | region below 30 mm in radius from the center of the said through-hole.

  The height from the tip of the second adhesive portion to the tip of the second protrusion is not particularly limited, but if it is too low, there is a possibility that the gas flow cannot be bypassed at the second adhesive portion. On the other hand, if the height from the tip of the second adhesive portion to the tip of the second protrusion is too high, a local force is likely to be applied to the resin film, and the resin film may be easily broken. For this reason, the height from the front-end | tip of a 2nd adhesion part to the front-end | tip of a 2nd protrusion part is normally set to 0.1-3 mm.

  It is also preferable that a slit is formed in the second protrusion. Thereby, it becomes possible to easily introduce the gas outside the container into the container from the through hole, and it is possible to further prevent the container from being recessed inside after the heating. Therefore, since the container wall can be formed thin, it is easy to reduce the manufacturing cost of the container by reducing the amount of material required for forming the container.

  It is also preferable that the inside of the container is partitioned by a partition wall, and the first projecting portion is continuously provided on the partition wall. As a result, the inside of the container can be divided into a plurality of compartments, and the contents can be divided and accommodated according to the type and size thereof, and the limited space inside the container can be used efficiently. Will be able to. It is also possible to increase the strength of the container. Furthermore, the package body in which the container is partitioned into a plurality of compartments as described above is likely to cause a temperature difference between the compartments during heating, and the significance of adopting the configuration of the present invention is deepened. This configuration is preferably used when food such as lunch boxes and side dishes are stored as contents.

  In addition, the above-mentioned problem is a container in which a first bonding portion for bonding the lower surface of the resin film is provided in an annular shape along the upper edge, and protrudes into the container wall and is equivalent to the upper edge of the container. A first protrusion reaching a certain height is formed, and an annular second for adhering a through-hole penetrating the container wall and a portion surrounding the through-hole to the lower surface of the resin film on the upper surface of the first protrusion This problem can also be solved by providing a container characterized in that an adhesive portion and a second protruding portion protruding higher than the upper edge of the second adhesive portion are provided. This container can be suitably used for the package.

  As described above, according to the present invention, it is possible to realize a package that can release the gas generated from the contents to the outside of the container with a simple structure with a small number of parts. It is also possible to provide a package that can cause the gas to flow throughout the interior of the container when gas is released from the through-hole provided in the container wall, and the contents can be heated uniformly. . Furthermore, it is possible to provide a container that does not easily dent inside even after the gas inside the container is released from the through hole. Furthermore, it is possible to provide a container that can be suitably used to configure the package.

It is the perspective view which showed the suitable embodiment of the package of this invention. It is the perspective view which showed the suitable embodiment of the container of this invention. It is the top view which looked at the container shown in FIG. 2 from upper direction. It is the figure which expanded the periphery of the left side through-hole in the container shown in FIG. It is sectional drawing which showed the state which cut | disconnected the periphery of the left side through-hole in the container shown in FIG. 4 by the YY plane. It is sectional drawing which showed the state which cut | disconnected the periphery of the left side through-hole in the package body before a heating start or immediately after a heating start with the surface equivalent to the YY surface in FIG. It is sectional drawing which showed the state which cut | disconnected the circumference | surroundings of the left side through-hole in the package after passing for a while from a heating start with the surface equivalent to the YY surface in FIG. The package of the present invention is a graph partition a, the temperature T _a of water _b, T _b are shown the results of measurement, respectively at the time of heating in a microwave oven. Partitioning the package of Comparative Example at the time of heating in a microwave oven a, water b temperature T _a, it is a graph showing the results of measurement of T _b, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Package 110 Container 111 1st adhesion part 112 1st protrusion part 113 Through-hole 114 2nd adhesion part 115 2nd protrusion part 116 Partition wall 117 Communication groove 120 Resin film 130 Contents

  Hereinafter, preferred embodiments of the package of the present invention and the container used therefor will be described more specifically with reference to the drawings. FIG. 1 is a perspective view showing a preferred embodiment of the package 100 of the present invention. FIG. 2 is a perspective view showing a preferred embodiment of the container 110 of the present invention. FIG. 3 is a plan view of the container 110 shown in FIG. 2 as viewed from above. FIG. 4 is an enlarged view of the periphery of the left through hole 113 in the container 110 shown in FIG. FIG. 5 is a cross-sectional view showing a state in which the periphery of the left through-hole 113 in the container 110 shown in FIG. 4 is cut along the YY plane.

1. Overall Configuration of Packaging Body As shown in FIG. 1, the packaging body 100 of the present embodiment adheres the lower surface of the resin film 120 to the first adhesive portion 111 provided in an annular shape along the upper edge (outer edge) of the container 110. By doing so, the contents 130 accommodated in the container 110 are sealed. A first protrusion 112 that protrudes into the container 110 and contacts the lower surface of the resin film 120 is formed on the container wall. Further, on the upper surface of the first projecting portion 112, a through hole 113 penetrating the container wall, an annular second adhesive portion 114 for weakly bonding a portion surrounding the through hole 113 to the lower surface of the resin film 120, and a first A second protrusion 115 protruding higher than the tip of the two adhesive portions 114 is provided.

2. Contents The type of the contents 130 is not particularly limited, but it is preferable that the contents 130 are required to be sealed in order to maintain quality, such as food. Especially, it is suitable as what accommodates the foodstuff which generate | occur | produces gas, such as water vapor | steam and a carbon dioxide gas.

  The food that generates water vapor is not particularly limited as long as it contains water. Soups such as miso soup and stew, rice such as white rice and fried rice, ramen and udon noodles, meat dishes and vegetables Examples are prepared dishes such as dishes and fish dishes. In particular, it is preferable as a container for storing food for cooking in a microwave oven for the purpose of cooking by heating in a microwave oven, and it is preferable as a storage for refrigerated storage or refrigeration. Among them, the food for cooking in a microwave oven stored in a frozen state is significant in that the heating by the latent heat generated when the water vapor is condensed by controlling the flow of the water vapor is performed uniformly. It is suitable as the contents 130 of the body 100. When the food for cooking in a microwave oven is stored frozen, the portion of the ice that is melted into water is less likely to heat up when heated in the microwave, whereas the portion where the ice melts becomes easier to heat up. This is because uneven heating tends to occur depending on the location.

  On the other hand, examples of foods that generate carbon dioxide include fermented foods such as kimchi and miso. In the package 100 of the present embodiment, a lunch box type container is used for the container 110, rice is stored in the section a of the container 110 (see FIG. 3), and the sections b to d of the container 110 are stored. Each contains a different kind of side dish.

3. Container The shape of the container 110 differs depending on the type of the contents 130 and is not particularly limited. As shown in FIG. 2, the container 110 according to the present embodiment has a substantially box shape with the top opened. As shown in FIG. 3, the inside of the container is partitioned into a plurality of partitions a to d by a partition wall 116. For this reason, the content 130 can be accommodated in different sections a to d according to the type and the like. Although the volume of the container 110 is not particularly limited, the container 110 of the present embodiment has a section a of 270 cc, sections b and d of 50 cc, and section c of 130 cc, for a total of 500 cc. The arrangement of the compartments a to d is not particularly limited, but it is preferable to arrange the compartments a as symmetrical as possible, for example, so that the inner shape of the container 110 is symmetrical. Thereby, it becomes easier to control the gas flow inside the container, and the temperature difference between the compartments a to d during heating can be easily suppressed. Also in the container 110 of the present embodiment, the compartments a to d are arranged symmetrically.

  Of each part of the partition wall 116, the upper edge of the part that partitions the partition a and the partition b, the upper edge of the part that partitions the partition a and the partition c, the upper edge of the part that partitions the partition a and the partition d, and the partition b and the partition As shown in FIG. 2, the upper edge of the part that partitions c and the upper edge of the part that partitions the partition c and the partition d are formed to be recessed downward, and the partitions a to d communicate with the partition wall 116. A communication groove 117 is provided. For this reason, the gas inside the container can come and go between the compartments, and even when the package 100 is heated by a microwave oven or the like, the temperatures of the compartments a to d are easily maintained. ing.

  The material of the container 110 is not particularly limited as long as it can exhibit a strength that does not easily break even when the contents 130 are accommodated, but a plastic that is excellent in productivity and sealability is usually employed. Examples of the plastic used for the container 110 include polyester resins, polyamide resins, polystyrene resins, polyvinyl chloride resins, polyacrylonitrile resins, etc., in addition to polyolefin resins such as polyethylene and polypropylene. Among these, polypropylene is suitable because it is excellent in moldability, rigidity, and heat sealability. When heat resistance is required for the container 110, it is preferable to use polypropylene blended with an inorganic filler such as talc. Thereby, the retort sterilization process can be performed on the contents 130. In this case, the amount of the inorganic filler is usually set to 10 to 50% by weight. The molding method of the container 110 is not particularly limited, and examples thereof include vacuum molding, injection molding, and sheet thermoforming.

  The thickness of the container wall is not particularly limited, but if it is too thin, the rigidity of the container 110 cannot be secured, and the container 110 may be greatly deformed when the internal pressure of the container 110 rises. For this reason, the thickness of the container wall is usually set to 0.2 mm or more. The thickness of the container wall is preferably 0.3 mm or more, and more preferably 0.4 mm or more. On the other hand, if the container wall is too thick, a large amount of material for the container 110 is required, and the manufacturing cost of the container 110 increases. For this reason, the thickness of the container wall is usually set to 1.2 mm or less. The thickness of the container wall is preferably 0.8 mm or less, and more preferably 0.6 mm or less. In the container 110 of this embodiment, the thickness of the container wall is 0.4 mm.

4). 1st adhesion part The 1st adhesion part 111 will not be specifically limited if it is provided in cyclic | annular form along the upper edge (outer edge) of the container 110, The flat formation may be sufficient. In the container 110 of this embodiment, as shown in FIG. 2, protrusions are provided along the upper edge (outer edge) of the container 110. Thereby, the lower surface of the resin film 120 can be easily bonded along the first bonding portion 111 with a uniform bonding strength. The cross-sectional shape of the ridges provided on the first adhesive portion 111 is not particularly limited, but the container 110 of the present embodiment has a substantially semicircular shape so that wrinkles are not easily formed on the resin film 120 around the first adhesive portion 111. I have to. Further, the height H ₁ (see FIG. 5) of the ridges provided in the first adhesive portion 111 is not particularly limited, but is about 1 mm in the container 110 of this embodiment.

  The adhesive of the resin film 120 in the first adhesive part 111 may use an adhesive, but considering productivity and hygiene, the resin film 120 and the container 110 may be fused by thermal welding or vibration welding. preferable. The adhesive strength of the resin film 120 in the first adhesive portion 111 is not particularly limited as long as it is higher than the adhesive strength of the resin film 120 in the second adhesive portion 114, but immediately after heating the package 100 with a microwave oven or the like, Although it can be easily peeled off, it is preferable that the package 100 is bonded with an adhesive strength that cannot be easily peeled off manually when the package 100 is at room temperature.

5. First Protrusion Portion The first protrusion portion 112 may be provided at only one location per container 110, but is preferably provided at a plurality of locations as shown in FIG. As a result, the through holes 113 can be provided at a plurality of locations, so that the gas inside the container can be more efficiently discharged to the outside of the container. The arrangement of the first projecting portions 112 is not particularly limited, but, as with the arrangement of the sections a to d, it is easier to suppress the temperature difference between the sections a to d during heating when they are arranged as symmetrically as possible. preferable. In the container 110 of this embodiment, the 1st protrusion part 112 is each provided in the both ends (left end part and right end part in FIG. 3) in a container inside.

  The height of the upper surface of the first protruding portion 112 is set to be substantially the same as or slightly lower than that of the first adhesive portion 111. The first protrusion 112 may have a shape in which the bottom wall (lower container wall) of the container 110 protrudes upward, or the side wall (lateral container wall) of the container 110 protrudes inward. It may be in the form of the above. The first protrusion 112 having such a configuration can be easily formed, for example, when the container 110 is vacuum formed. In the container 110 of this embodiment, as shown in FIG. 2, the corner container wall formed by the bottom wall and the side wall of the container 110 protrudes inward and upward of the container 110. The 1st protrusion part 112 is continuously formed in the partition wall 116, and can also show | play the function as a partition. For this reason, the space inside the container can be used without waste.

6). Through hole As shown in FIG. 2, a through hole 113 is provided in the vertical direction on the container wall that forms the upper surface of the first protrusion 112. The position at which the through hole 113 is provided is not particularly limited as long as it is the upper surface of the first protrusion 112, but is preferably provided at a position 5 mm or more away from the upper edge (outer edge) of the container 110 toward the center. Since the package 100 is generally held near the upper edge (outer edge) of the container 110 and carried, if the through hole 113 is close to the upper edge (outer edge) of the container 110, the package 100 after heating is wrapped. This is because hot air released from the through hole 113 may touch the finger when carrying the body 100. The through-hole 113 is preferably 10 mm or more away from the upper edge (outer edge) of the container 110 toward the center, and more preferably 15 mm or more. In the container 110 of this embodiment, the through hole 113 is provided at a position 20 mm away from the upper edge (outer edge) of the container 110 toward the center.

7). Second Adhering Portion The second adhering portion 114 is not particularly limited as long as it is provided annularly around the through hole 113 on the upper surface of the first projecting portion 112, and may be formed flat. . In the container 110 of this embodiment, as shown in FIG. Accordingly, the lower surface of the resin film 120 can be easily bonded along the second bonding portion 114 with a uniform bonding strength. The cross-sectional shape of the protrusions provided on the second adhesive portion 114 is not particularly limited, but the container 110 according to the present embodiment has a substantially semicircular shape as with the first adhesive portion 111. Further, the height H ₂ (see FIG. 5) of the ridges provided in the second adhesive portion 114 is not particularly limited, but is about 0.4 mm in the container 110 of this embodiment. Further, the radius at which the protrusions of the second adhesive portion 114 are provided is not particularly limited, but is approximately 6 mm in the container 110 of the present embodiment, and the protrusions pass between the through hole 113 and the second protrusion 115. It is like that.

  Although the adhesive may be used for the adhesion of the resin film 120 in the second adhesion part 114, it is preferable that the resin film 120 is fused by thermal welding or vibration welding similarly to the first adhesion part 111. The adhesive strength of the resin film 120 at the second adhesive portion 114 is not particularly limited as long as it is lower than the adhesive strength of the resin film 120 at the first adhesive portion 111. As a method for making the adhesive strength at the second adhesive portion 114 lower than the adhesive strength at the first adhesive portion 111, for example, when the resin film 120 is thermally welded, the sealing temperature and the sealing pressure at the second adhesive portion 114 are set to Examples thereof include a method of lowering the sealing temperature and the sealing pressure at the one bonding part 111 and a method of making the bonding area at the second bonding part 114 smaller than the bonding area at the first bonding part 111.

8). The second protrusion 115 is not particularly limited as long as it can control the flow of gas reaching the through hole 113, but is provided substantially perpendicular to the radial direction of the through hole 113. It is preferable to have a wall-like shape. This makes it possible to more reliably control the gas flow inside the container. In the container 110 of this embodiment, as shown in FIG. 2, a wall-like second protruding portion 115 perpendicular to the radial direction of the through hole 113 is provided in a substantially arc shape with the through hole 113 as the center. The second projecting portion 115 is disposed on the center side of the container 110 when viewed from the center of the through hole 113. For this reason, the gas inside the container can reach the through-hole 113 after bypassing the second protrusion 115, and when the gas inside the container is released to the outside of the container, A large gas flow can be generated.

  The distance from the through hole 113 to the second protrusion 115 is not particularly limited. However, if the through hole 113 and the second protrusion 115 are too close, the resin film 120 may not be properly bonded by the second bonding portion 114. . For this reason, the 2nd protrusion part 115 is normally distribute | arranged to the area | region more than radius 5mm from the center of the through-hole 113. FIG. The second protrusion 115 is more preferably disposed in a region having a radius of 7 mm or more from the center of the through hole 113. On the other hand, if the through hole 113 and the second projecting portion 115 are too far apart, it is difficult to control the flow of the gas that reaches the through hole 113, and the temperature inside the container 110 may easily vary. For this reason, the 2nd protrusion part 115 is normally distribute | arranged to the area | region below 30 mm in radius from the center of the through-hole 113. FIG. The second protrusion 115 is preferably disposed in a region having a radius of 20 mm or less from the center of the through hole 113, and more preferably disposed in a region having a radius of 15 mm or less. In the present embodiment, the second projecting portion 115 is provided at a location about 10 mm away from the center of the through hole 113.

Further, the height H ₃ (see FIG. 5) from the tip of the second adhesive portion 114 to the tip of the second protrusion 115 is not particularly limited, but if the second protrusion 115 is too low, the second adhesive portion 114 is not too low. There is a risk that the gas flow cannot be bypassed. Therefore, the height _{H 3,} usually set above 0.1 mm. The height _{H 3} is preferable to be 0.3mm or more, and more preferably 0.5mm or more. On the other hand, if the height H ₃ to the tip from the tip of the second adhesive portion 114 second protrusion 115 is too high, easily joined by local force to the resin film 120, is a risk that the resin film 120 is easily broken is there. For this reason, the height from the front-end | tip of a 2nd adhesion part to the front-end | tip of a 2nd protrusion part is normally set to 3 mm or less. The height _{H 3} is preferable to be 2mm or less, and more preferably 1mm or less. A container 110 of the present embodiment, the height _{H 3} has a 0.6 mm.

9. Slit By the way, in the container 110 of this embodiment, as shown in FIG. 4, a slit is formed at the substantially central portion in the longitudinal direction of the second protrusion 115. Therefore, when the resin film 120 swelled upward due to the gas being released from the through hole 113 and the internal pressure of the container 110 being lowered returns to the original state, the gas outside the container naturally flows into the container. It is possible to prevent the deformation of the container 110 after heating (arrow C in FIG. 4). Only one slit may be provided for each second protrusion 115, or a plurality of slits may be provided for one second protrusion 115.

  The width of the slit varies depending on the distance from the through hole 113 to the second protrusion 115, the volume of the container 110, and the like, and is not particularly limited. However, if the slit width is too narrow, it may be difficult to introduce gas outside the container 110 into the container 110 when the resin film 120 returns to its original state. For this reason, the width of the slit is usually set to 0.5 mm or more. The width of the slit is preferably 1 mm or more, and more preferably 1.5 mm or more. On the other hand, if the width of the slit is too wide, the gas flow inside the container 110 may not be controlled by the second protrusion 115. For this reason, the width of the slit is usually set to 5 mm or less. The width of the slit is preferably 4 mm or less, and more preferably 3 mm or less. In the container 110 of this embodiment, the width of the slit is about 2 mm.

10. Resin Film The material of the resin film 120 is not particularly limited, and various resins can be used. The resin film 120 may be a single layer film or a multilayer film. Among these, a multilayer film in which a heat seal layer is superimposed on a biaxially stretched resin layer is suitable as the resin film 120. This is because this type of multilayer film is not only easily deformed by heat but can withstand heating by a microwave oven, and also has excellent heat sealability. The resin film 120 of this embodiment is a multilayer film in which a base material layer made of biaxially stretched polypropylene, an oxygen barrier resin layer made of polyacrylonitrile resin, and a heat seal layer made of polyethylene resin are overlapped. The lower surface (heat seal layer) of the resin film 120 is thermally welded to the first adhesive portion 111 provided in an annular shape along the upper edge of the container 110.

  The thickness of the resin film 120 is not particularly limited, but if it is too thin, the resin film 120 may be easily broken. For this reason, the total thickness of the resin film 120 is normally set to 30 μm or more. The total thickness of the resin film 120 is preferably 55 μm or more, and more preferably 60 μm or more. On the other hand, if the resin film 120 is too thick, even if the internal pressure of the container 110 increases, the resin film 120 is unlikely to bulge outward, and the second adhesive portion 114 may not be easily peeled off. For this reason, the total thickness of the resin film 120 is normally set to 80 μm or less. The total thickness of the resin film 120 is preferably 70 μm or less, and more preferably 65 μm or less. The total thickness of the resin film 120 of this embodiment is 60 μm.

11. Operation Next, an operation when the package 100 is heated in the microwave will be described. 6 is a cross-sectional view showing a state where the periphery of the left through-hole 113 in the package 100 before starting heating or immediately after starting heating is cut along a plane corresponding to the YY plane in FIG. FIG. 7 is a cross-sectional view showing a state in which the periphery of the left through-hole 113 in the package 100 after cutting for a while from the start of heating is cut along a plane corresponding to the YY plane in FIG. 4.

  Before the heating start of the package 100 or immediately after the heating start, as shown in FIG. 6, the resin film 120 is bonded by the second bonding portion 114, and the through hole 113 is closed by the resin film 120. It has become. The gas inside the container flows naturally between a compartment having a high temperature and a compartment having a low temperature through a communication groove 117 provided on the upper edge of the partition wall 116, and the like. Distribution can be secured between the sections. For this reason, a big temperature difference does not arise in the contents 130 accommodated in each division.

  After a while from the start of heating the package 100, water vapor is generated from the contents 130, and the internal pressure of the container 110 begins to rise. The resin film 120 starts to bulge upward due to the internal pressure of the container 110. When the swelling of the resin film 120 reaches the limit, the resin film 120 is peeled off at the second adhesive portion 114 that is weakly bonded, and the inside of the container and the outside of the container are communicated with each other through the through-hole 113 as shown in FIG. It becomes. In the first bonding portion 111 that has been strongly bonded, the resin film 120 is still bonded.

  When the inside of the container communicates with the outside of the container through the through hole 113, the gas inside the container is released to the outside of the container through the through hole 113 (arrow D in FIG. 7). As shown by arrows A and B in FIG. 4, the gas released to the outside of the container bypasses the second protrusion 115 and reaches the through hole 113 inside the container. When the gas is discharged from the container, a large gas flow is generated throughout the container. For this reason, it is easy to keep the temperature of the contents 130 accommodated in each section uniform.

  By the way, if the through hole 113 is closed immediately after the gas is released from the through hole 113, the internal pressure of the container 110 becomes lower than the external pressure due to the condensation and contraction of the gas inside the container, and the heated container 110 is May dent inside. However, in the package 100 of the present invention, the resin film 120 around the through hole 113 is supported by the second protrusion 115 even after the gas is released from the through hole 113. For this reason, the gas outside the container naturally flows again into the container through the through-hole 113, and the internal pressure of the container 110 is not significantly reduced after the package 100 is heated. The gas introduced into the container can quickly reach not only the periphery of the through-hole 113 but also the central part of the container 110 by passing through the slit provided in the second protrusion 115. (Arrow C in FIG. 4). For this reason, the dent of the container 110 after a heating can be prevented more reliably.

12 Experiment In order to demonstrate that the package 100 of the present invention can uniformly heat the contents 130, the package 100 containing water as the contents 130 is heated in a microwave oven for 6 minutes, and the compartment a ( The temperature of the water in the compartment a (referred to as T _a ) and the temperature of the water in the compartment b (referred to as T _b ) by the temperature measuring elements previously stored in the compartment b (see FIG. 3). An experiment was conducted to measure each. 90 cc of water was placed in the compartment a, 30 cc of water was placed in the compartments b and d, and 50 cc of water was placed in the compartment c. The output of the microwave oven was set to 500W. Moreover, the same measurement was performed also about the package using the container same as the container 110 shown in FIG. 3 except the 2nd protrusion part 115 not being provided as a comparative example.

FIG. 8 is a graph showing the results of measuring the water temperatures T _a and T _b in the compartments a and b when the package 100 of the present invention is heated in a microwave oven. FIG. 9 is a graph showing the results of measuring the water temperatures T _a and T _b of the compartments a and b when the package of the comparative example was heated in a microwave oven. 8 and 9, the elapsed time is the elapsed time from the start of heating in a microwave oven, T _o is the temperature of the vessel outside air.

Looking at Figure 8, the package 100 of the present invention, in about 200 seconds from the start of heating by the microwave oven, the temperature T _a of the water compartment a temperature T _b of the water compartment b are substantially equal in the vicinity of 100 ° C. You can see that In contrast, referring to FIG. 9, the package of Comparative Example, it can be seen that the temperature T _a of the water compartment a temperature T _b of the water compartment b is taking approximately 250 seconds to approximately equal . Further, towards the package of the present invention, than the packaging material of Comparative Example, it can also be seen that the difference between the temperature T _a and the temperature T _b is generally smaller. From the above measurement results, it can be seen that the package 100 of the present invention can heat the contents 130 uniformly.

Claims (6)

A package that seals the contents contained in the container by adhering the lower surface of the resin film to the first adhesive portion provided in an annular shape along the upper edge of the container,
The inside of the container is divided into a plurality of compartments by a partition wall,
A first protrusion that protrudes from the container wall into the container and contacts the lower surface of the resin film is formed continuously with the partition wall ,
A through hole penetrating the container wall on the upper surface of the first projecting portion, an annular second adhesive portion for weakly adhering a portion surrounding the through hole to the lower surface of the resin film, and the center of the container when viewed from the through hole a second projecting higher than the upper edge of the bonded portion Rutotomoni second projecting portion different compartments arranged wall-like ones of said plurality of compartments on both sides is provided disposed to the side,
When the internal pressure of the container increases, the resin film swells upward and the second adhesive part peels off, and after the gas inside the container bypasses the second projecting part, it is released to the outside of the container through the through hole. A package characterized by the above. Second protrusions, the through hole package of claim 1, wherein arranged in the following areas a radius 30mm from the center of. The package according to claim 1 or 2 , wherein the second adhesive part is a ridge, and the height from the tip of the second adhesive part to the tip of the second protruding part is 0.1 to 3 mm. The package according to any one of claims 1 to 3 , wherein the through hole is provided at a position 5 mm or more away from the upper edge of the container toward the center. The package according to any one of claims 1 to 4, wherein a slit having a width of 5 mm or less is formed in the second protrusion. A first adhesive part for adhering the lower surface of the resin film is a container provided annularly along the upper edge,
The inside of the container is divided into a plurality of compartments by a partition wall,
A first protrusion that protrudes from the container wall into the container and reaches a height equivalent to the upper edge of the container is formed continuously from the partition wall ,
A through hole penetrating the container wall on the upper surface of the first projecting portion; an annular second adhesive portion for adhering a portion surrounding the through hole to the lower surface of the resin film; and a container center side when viewed from the through hole wherein arranged are in a second protruding higher than the upper edge of the bonded portion Rutotomoni second projecting portion different compartments arranged wall-like ones of said plurality of compartments on both sides that is provided in the container.

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