Packaging container for sterilization

Abstract

The present invention provides a packing container including a container body that includes a storage portion and a flange portion. The flange portion includes: a primary seal area subjected to primary sealing with a lid member; a secondary seal area subjected to secondary sealing with the lid member; a flange uppermost portion located at an uppermost position of an upper surface of the flange portion; a flange lower portion located downward of the upper surface of the flange uppermost portion; and a penetrating area located inward of the primary seal area and having a through hole penetrating through the flange portion. When sealing is performed in the primary seal area, a clearance is formed between the upper surface of the flange lower portion and the lid member and a flow passage through which gas can flow between the outside and the inside of the storage portion is formed between the lid member and the flange portion. The flow passage is configured to close when sealing is performed in the secondary seal area.

Description

[Technical Field]

[0001] [Mutual Reference of Related Applications]

[0002] This application asserts priority of Japanese Patent Application No. 2019-223878 and is incorporated into the description of this application by reference.

[0001] The present invention relates to packaging containers for sterilization treatment, for example to packaging and sterilizing food such as vegetables. [Previous Technology]

[0002] In packaged foods, there are foods that have been prepared and processed in food factories, etc., and are contained in containers with openings, and are distributed while the containers are sealed or covered. However, since packaged foods using top seals or covers are not completely sealed, external gases may enter the container. Therefore, the shelf life of such packaged foods is very short, about 1 to 2 days, and there is a problem of extremely high waste and loss rates (poor product yield).

[0003] Recently, such packaged foods have been circulating in the market, namely those whose containers and lids are completely sealed, such as by heat sealing, thus extending their shelf life. Among them are packaged foods whose shelf life exceeds 2 weeks through refrigeration.

[0004] However, even if containers can be sealed by heat sealing or other means to prevent the invasion of bacteria from the outside, the interior of the formed container is not completely sterile. Therefore, it is highly likely that bacteria will multiply inside the container due to changes in the environment during distribution. Therefore, in order to extend the shelf life, it is necessary to make the working environment in the food factory as close to a sterile state as possible, thus requiring strict management of cleanliness. In the past, a method has been proposed in which food is heated and sterilized while contained in a container, and then the container body is sealed with a lid in a cleanroom (sterile room) (Patent Document 1). For example, the cleanliness of the working environment for processing prepared food is managed to a high level, such as NASA-standard cleanrooms of 10,000 or 1,000. However, when such cleanrooms are introduced, there are problems with the high cost of setting up and maintaining air conditioning equipment.

[0005] In addition to food, there are various other objects that need to be sterilized before they are distributed in the market as products, and therefore require efficient sterilization of such objects.

[0005] [Previous Technical Documents]

[0005] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-9937

[0007] The object of the present invention is to provide a packaging container that can be better used when sterilizing the contents. For example, the object is to provide a packaging container that can be better used in sterilizing food, which is an example of the contents, and can extend the quality retention period of the food.

[0008] The packaging container of the present invention is a sterilization treatment packaging container used to expose the contents contained therein to a sterilizing gas for sterilization, and then seal the contents for circulation. The container body comprises: a receiving portion having an opening at the top for receiving the contents, and a flange portion extending outward from the opening edge of the receiving portion; the flange portion has: a primary sealing area, which is sealed once with a cover member covering the opening in a primary sealing process; a secondary sealing area, which is sealed a second time with the cover member in a secondary sealing process after the primary sealing process; and an uppermost portion of the flange. Its upper surface is located at the uppermost point of the upper surface of the flange portion; the lower flange portion has its upper surface located below the uppermost upper surface of the flange portion; and at least one through area is located further inside than the aforementioned primary sealing area and is provided with a through hole that penetrates the aforementioned flange portion; and the aforementioned flange portion is configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a flow path is formed between the aforementioned cover member supported by the uppermost part of the aforementioned flange and the aforementioned lower flange portion, allowing gas to flow between the outside and the aforementioned receiving portion; after the aforementioned cover member and the aforementioned secondary sealing area are sealed, the aforementioned flow path is closed.

[0009] In addition, in the aforementioned packaging container, the aforementioned through hole can also be formed by forming a crack in a portion of the aforementioned through area.

[0010] The aforementioned through area may also have a curved surface that bulges upward, and the upper end of the aforementioned curved surface may also form the uppermost part of the aforementioned flange.

[0011] In addition, in the aforementioned packaging container, the aforementioned through area may also be a recessed portion that is recessed downwards, and the aforementioned crack may also be formed in the recessed portion.

[0012] In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided around the entire circumference of the opening edge of the aforementioned receiving portion, and the aforementioned through area may also be provided in multiples and arranged in opposite positions across the aforementioned receiving portion.

[0013] Another packaging container of the present invention is a packaging container for exposing the contents contained therein to a sterilizing gas for sterilization, and then sealing the contents for circulation. The packaging container has a container body, which includes: a receiving portion having an opening at the top and containing the contents, and a flange portion extending outward from the opening edge of the receiving portion; the flange portion has: a primary sealing area, which is sealed once with a cover member covering the opening in a primary sealing process; and a secondary sealing area, which is sealed twice with the cover member in a secondary sealing process after the primary sealing process; and the flange portion is configured such that after the cover member and the primary sealing area are sealed together, a flow path is formed between the flange portion and the cover member, allowing gas to flow between the outside and the receiving portion, and after the cover member and the secondary sealing area are sealed, the flow path is closed.

[0014] In addition, at least one through hole through the flange portion of the aforementioned packaging container may be provided at a location further inside than the aforementioned primary sealing area, and the aforementioned through hole may also be configured to become part of the aforementioned flow path.

[0015] Furthermore, in the aforementioned packaging container, the aforementioned through hole can also be formed by forming a crack on a portion of the aforementioned flange.

[0016] In addition, in the aforementioned packaging container, the aforementioned flange portion may also have: an uppermost flange portion formed by deforming a portion of the aforementioned flange portion upward with the aforementioned crack as the boundary, and the aforementioned flow path may also be formed between the aforementioned cover member supported by the uppermost flange portion and the aforementioned flange portion.

[0017] Furthermore, in the aforementioned packaging container, a portion of the aforementioned flange portion that deforms upwards may also have a curved surface that bulges upwards.

[0018] In addition, in the aforementioned packaging container, the aforementioned flange portion may also have: an uppermost flange portion, the upper surface of which is located at the uppermost of the upper surface of the flange portion, and the aforementioned packaging container may also form the aforementioned flow path between the aforementioned cover member and the aforementioned flange portion, which is supported by the uppermost flange portion.

[0019] In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided around the entire circumference of the opening edge of the aforementioned receiving portion, and a plurality of the aforementioned through holes may also be provided and disposed at opposite positions separated from the aforementioned receiving portion.

[0020] Furthermore, in the aforementioned packaging container, the upper surface of the aforementioned primary sealing area may also be located at the uppermost of the upper surface of the aforementioned flange portion, and the upper surface of the aforementioned secondary sealing area may also be located below the upper surface of the aforementioned primary sealing area. The aforementioned flange portion may also be configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a gap is formed between the upper surface of the aforementioned secondary sealing area and the lower surface of the aforementioned cover member, and the aforementioned gap may also be configured in such a way as to become part of the aforementioned flow path.

[0021] In addition, in the aforementioned packaging container, the aforementioned receiving portion may also include a base plate containing the contents, and the upper surface of the aforementioned base plate may also have an uneven shape.

[0022] The packaging container of the present invention may also have a lid member, and the aforementioned container body and the aforementioned lid member may also be composed of a multi-layer structure containing at least one gas barrier layer. [Simplified Explanation of the Diagram]

[0023] Figure 1A is a schematic diagram of one embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container.

[0023] Figure 1B is a schematic diagram of one embodiment of the aforementioned packaging container, and is a side view of the aforementioned packaging container.

[0023] Figure 2 is a cross-sectional view at position II-II in Figure 1A.

[0023] Figure 3 is a diagram showing the various processes in the aforementioned method of manufacturing the packaging container.

[0023] Figure 4A is a schematic diagram of the above-mentioned packaging container after the through hole forming process and the food containing process, and is a top view of the above-mentioned packaging container.

[0023] Figure 4B is a schematic diagram of the aforementioned packaging container after the through hole forming process and the food containing process, and is a side view of the aforementioned packaging container.

[0023] Figure 5 is a cross-sectional view at position VV in Figure 4A.

[0023] Figure 6A is a schematic diagram of the aforementioned packaging container after one sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 6B is a schematic diagram of the aforementioned packaging container after the first sealing process, and is a side view of the aforementioned packaging container.

[0023] Figure 7 is a cross-sectional view at position VII-VII of Figure 6A.

[0023] Figure 8A is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 8B is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a side view of the aforementioned packaging container.

[0023] Figure 9 is a cross-sectional view at position IX-IX of Figure 8A.

[0023] Figure 10A is a schematic diagram of other embodiments of the packaging container of the present invention, and is a top view of the aforementioned packaging container.

[0023] Figure 10B is a schematic diagram of other embodiments of the packaging container of the present invention, and is a cross-sectional view at position XX of Figure 10A.

[0023] Figure 11A is a schematic diagram after the through hole formation process of the aforementioned packaging container, and is a top view of the aforementioned packaging container.

[0023] Figure 11B is a schematic diagram after the process of forming the through hole of the aforementioned packaging container, and is a cross-sectional view at position XI-XI of Figure 11A.

[0023] Figure 12A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 12B is a schematic diagram of another embodiment of the packaging container of the present invention after the first sealing process, and is a cross-sectional view at position XII-XII of Figure 12A.

[0023] Figure 13A is a schematic diagram of the secondary sealing process of other embodiments of the aforementioned packaging container, and is a top view of the aforementioned packaging container.

[0023] Figure 13B is a schematic diagram of the secondary sealing process of other embodiments of the aforementioned packaging container, and is a cross-sectional view at position XIII-XIII of Figure 13A.

[0023] Figure 14A is a schematic diagram of the packaging container shown in Figure 12A after the secondary sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 14B is a schematic diagram of the packaging container shown in Figure 12A after the secondary sealing process, and is a cross-sectional view at position XIV-XIV in Figure 14A.

[0023] Figure 15A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 15B is a schematic diagram of another embodiment of the packaging container of the present invention after the first sealing process, and is a cross-sectional view at position XV-XV of Figure 15A.

[0023] Figure 16A is a schematic diagram of the secondary sealing process of other embodiments of the aforementioned packaging container, and is a top view of the aforementioned packaging container.

[0023] Figure 16B is a schematic diagram of the secondary sealing process of other embodiments of the aforementioned packaging container, and is a cross-sectional view at position XVI-XVI of Figure 16A.

[0023] Figure 17A is a schematic diagram of other embodiments of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

[0023] Figure 17B is a schematic diagram of other embodiments of the packaging container of the present invention, which is a top view of the aforementioned packaging container after the through hole forming process.

[0023] Figure 18A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 18B is a schematic diagram of another embodiment of the packaging container of the present invention after the first sealing process, and is a cross-sectional view at position XVIII-XVIII of Figure 18A.

[0023] Figure 19A is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 19B is a schematic diagram of the secondary sealing process of the aforementioned packaging container, and is a cross-sectional view at position XIX-XIX of Figure 19A.

[0023] Figure 20A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 20B is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a cross-sectional view at position XX-XX of Figure 20A.

[0023] Figure 21A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 21B is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a cross-sectional view at position XXI-XXI in Figure 21A.

[0023] Figure 22A is a schematic diagram of another embodiment of the packaging container of the present invention after a first sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 22B is a schematic diagram of another embodiment of the packaging container of the present invention after the first sealing process, and is a cross-sectional view at position XXII-XXII of Figure 22A.

[0023] Figure 23A is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a top view of the aforementioned packaging container.

[0023] Figure 23B is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a cross-sectional view at position XXIII-XXIII of Figure 23A.

[0023] Figure 24A is a schematic diagram of the through hole forming process in another embodiment of the packaging container of the present invention, and is a top view of the aforementioned packaging container.

[0023] Figure 24B is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a cross-sectional view at position XXIV-XXIV of Figure 24A.

[0023] Figure 25A is a schematic diagram of the through hole forming process in another embodiment of the packaging container of the present invention, and is a top view of the aforementioned packaging container.

[0023] Figure 25B is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a cross-sectional view at the XXV-XXV position of Figure 25A.

[0023] Figure 26A is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a top view showing a modified example of Figure 24A.

[0023] Figure 26B is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a partial top view showing a modified example of Figure 25A.

[0023] Figure 27A is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a cross-sectional view showing a modified example of Figure 24A.

[0023] Figure 27B is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a cross-sectional view showing a modified example of Figure 25A.

[0023] Figure 28A is a schematic diagram of the through hole forming process in another embodiment of the packaging container of the present invention, and is a top view of the aforementioned packaging container.

[0023] Figure 28B is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a cross-sectional view at position XXVIII-XXVIII in Figure 28A.

[0023] Figure 29A is a cross-sectional view used to illustrate the through-hole forming process in the aforementioned packaging container, showing the state before the through-hole forming process.

[0023] Figure 29B is a cross-sectional view used to illustrate the process of forming a through hole in the aforementioned packaging container, showing the process of forming a crack in the flange.

[0023] Figure 29C is a cross-sectional view used to illustrate the process of forming the through hole in the aforementioned packaging container, showing the process of forming the uppermost part of the flange.

[0023] Figure 29D is a cross-sectional view used to illustrate the process of forming the through hole in the aforementioned packaging container, showing the state after the uppermost part of the flange is formed.

[0023] Figure 30A is a schematic diagram of other embodiments of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

[0023] Figure 30B is a schematic diagram of other embodiments of the packaging container of the present invention, and is a cross-sectional view of Figure 30A.

[0023] Figure 30C is a schematic diagram of other embodiments of the packaging container of the present invention, which is a cross-sectional view after the through hole forming process.

[0023] Figure 31A is a schematic diagram of other embodiments of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

[0023] Figure 31B is a schematic diagram of other embodiments of the packaging container of the present invention, and is a cross-sectional view of Figure 31A.

[0023] Figure 31C is a schematic diagram of other embodiments of the packaging container of the present invention, which is a cross-sectional view after the through hole forming process.

[0023] Figure 32A is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a schematic diagram showing the first modified example.

[0023] Figure 32B is a schematic diagram of the through hole forming process in another embodiment of the packaging container of the present invention, and is a schematic diagram showing the second modified example.

[0023] Figure 32C is a schematic diagram of the through hole forming process in other embodiments of the packaging container of the present invention, and is a schematic diagram showing the third modified example.

Implementation Method

[0024] An embodiment of the present invention will now be described with reference to Figures 1 to 9. Figures 1 and 2 are diagrams showing an embodiment of the packaging container of the present invention. Furthermore, Figure 3 is a diagram illustrating an embodiment of the manufacturing method of the packaged food of the present invention, and Figures 4 to 9 are diagrams showing the various steps of this manufacturing method in sequence.

[0025] First, the structure of a packaging container according to one embodiment of the present invention will be described. The packaging container of the present invention is a packaging container used for sterilization treatment, in which food, as an example of a contents contained therein, is exposed to heated steam, as an example of a sterilization gas, for sterilization, and then the contents (e.g., food) are sealed for distribution as packaged food. As shown in Figures 1 and 2, the packaging container 1 has a container body 4, which includes: a receiving portion 2 having an opening 20 at the top, and a flange portion 3 extending outward from the opening edge 21 of the receiving portion 2.

[0026] Hereinafter, the vertical direction in the packaging container 1 is consistent with the vertical direction in Figures 1, 2, 4 to 9. In addition, the inner and outer sides of the flange portion 3 are consistent with the side of the flange portion 3 that is close to the opening edge 21 and the side that is far away from it.

[0027] As shown in Figures 1A and 1B, the container body 4 is a container that can be closed by a lid member. The container body 4 of this embodiment is tray-shaped, but it can also be any shape such as a cup or bottle. Furthermore, the container body 4 is made of synthetic resin. The thickness of the container body 4 is not uniform depending on the location, but it can also be the same in any location. In the container body 4 of this embodiment, the thickness of the flange 3 is greater than the thickness of the receiving portion 2. In the container body 4 of this embodiment, the receiving portion 2 and the flange 3 are composed of a single component. Specifically, the container body 4 is constructed by molding a single sheet.

[0028] Furthermore, the cover member of this embodiment is flexible. The cover member is, for example, made of a membrane material made of synthetic resin. Specifically, the membrane material constituting the cover member is a membrane material made of biaxially stretched plastic.

[0029] The receiving part 2 is a part for receiving food. In this embodiment, the receiving part 2 includes a bottom plate 22 located below. In addition, the receiving part 2 includes a side wall 23 extending upward from the outer periphery of the bottom plate 22.

[0030] The base plate 22 is, for example, a rectangular plate with rounded corners. In addition, the base plate 22 has: an upper surface 220 that comes into contact with food; and a lower surface 221 that becomes the surface on which the container body 4 is placed when it is placed on the placement surface.

[0031] The upper surface 220 of the base plate has a concave-convex shape. Specifically, a plurality of base plate protrusions 222 are provided at the center of the upper surface 220 of the base plate, excluding the four corners. Furthermore, the four corners of the upper surface 220 of the base plate are formed by inclined surfaces 223 of the base plate that are closer to the apex of each corner and are positioned higher.

[0032] The portions of the bottom plate protrusions 222 are arranged at approximately equal or uneven intervals. A vapor flow section is formed between a pair of bottom plate protrusions 222, 222, and the bottom plate protrusions 222 support the contents contained in the container body 4, for example, in a point contact or line contact manner. Furthermore, the bottom plate protrusions 222 are designed in a manner that minimizes the contact area between the bottom plate protrusions 222 and the contents.

[0033] In the embodiment shown in FIG1A, a plurality of steam flow portions formed between the bottom plate protrusions 222, 222 are arranged at approximately equal intervals. According to this configuration, when the contents (e.g., food) contained in the container body 4 are sterilized by steam, steam can flow in not only from the upper surface and sides of the contents, but also from the lower surface of the contents through the steam flow path formed at the bottom, thereby sterilizing the contents by steam more evenly and effectively.

[0034] The height of the bottom plate protrusion 222 is not particularly limited, but it is based on the lowest inner surface of the container bottom (i.e., the lowest inner surface of the container body 4), for example, 2 mm or more, 3 mm or more, or 4 mm or more. Furthermore, the height of the bottom plate protrusion 222 is not particularly limited, but it is based on the lowest inner surface of the container bottom, for example, 15 mm or less, 13 mm or less, or 10 mm or less. By placing the height of the bottom plate protrusion 222 within this range, steam can more easily flow into the steam flow path, allowing for more effective steam sterilization of the lower surface of the contents.

[0035] The height of the bottom plate protrusion 222 is preferably 10% to 40% of the depth of the container body 4 (i.e., the distance from the opening 20 of the container body 4 to the lowest part of the inner surface in the vertical direction). According to this configuration, since the cross-sectional area of ​​the steam flow path is increased, steam flows more easily into the steam flow path, and steam sterilization of the lower surface side of the contents can be performed more effectively.

[0036] The inclined surface 223 of the base plate is provided to eliminate the corners of the receiving portion 2. For example, when taking out food contained in the receiving portion 2, the inclined surface 223 of the base plate prevents the food from getting stuck near the corners of the base plate 22 and makes it easy to take out the food from the receiving portion 2. In addition, the inclined surface 223 of the base plate is arranged with a gap between it and the protrusion 222 of the base plate.

[0037] The side wall 23 is constructed such that the higher the part is, the wider it is when viewed from above. The upper edge of the side wall 23 forms the opening edge 21 of the receiving part 2.

[0038] The flange portion 3 is the part that is sealed to the cover member. The flange portion 3 is provided, for example, around the entire circumference of the opening edge 21. In this embodiment, the flange portion 3 is generally plate-shaped and is arranged in a ring shape to surround the receiving portion 2 when viewed from above. Specifically, the flange portion 3 is a ring shape with four corners when viewed from above.

[0039] Furthermore, as shown in FIG2, the flange portion 3 has an upward-facing upper flange surface 30 and a downward-facing lower flange surface 35. Moreover, the flange portion 3 has a primary sealing region 31 that is sealed with the cover member covering the opening 20 in a primary sealing process, and a secondary sealing region 32 that is sealed with the cover member in a secondary sealing process. Additionally, the flange portion 3 has an uppermost flange portion 33 and a lower flange portion 34. The uppermost flange portion 33 has an uppermost flange surface 330 located at the top of the upper flange surface 30. The lower flange portion 34 has a lower flange surface 340 located below the uppermost flange surface 330.

[0040] In this embodiment, the flange portion 3 has a through region 36 with a through hole penetrating the flange portion 3 (refer to FIG. 1A). In this embodiment, the through hole, i.e., the through region 36, is located further inside than the primary sealing region 31. The through hole provided in the through region 36 penetrates between the lower surface 35 and the upper surface 30 of the flange. Furthermore, in this embodiment, the flange portion 3 has a plurality of through regions 36.

[0041] The number of through regions 36 provided in the flange portion 3 may be one, but it is preferable to provide both through holes for gas to flow into the flange portion 3 and through holes for gas to flow out of the flange portion 3, so it is preferable to have a plurality of them. Specifically, the flange portion 3 is provided with the same number of through regions 36 as the number of corner portions of the flange portion 3 (for example, four in this embodiment).

[0042] The primary sealing area 31 is part of the flange portion 3 and is used to temporarily seal the area between the cover member and the flange portion 3 by means of a primary sealing process. The primary sealing process is performed after the food is contained in the containing portion 2 and before the food is sterilized.

[0043] In this embodiment, the primary sealing region 31 is located on the outer periphery of the flange portion 3. Furthermore, the primary sealing region 31 is continuous in the circumferential direction of the opening edge 21. Specifically, the primary sealing region 31 extends continuously in the circumferential direction on the outer periphery of the flange portion 3, further inward than the outer periphery. More specifically, the primary sealing region 31 extends continuously in the circumferential direction, covering the entire circumference of the opening edge 21, on the outer periphery of the flange portion 3, further inward than the outer periphery.

[0044] The secondary sealing area 32 is the area where the cover member and the flange 3 are sealed during the secondary sealing process, which is a sealing process. The secondary sealing process is performed after the food contained in the receiving part 2 is sterilized. The secondary sealing area 32 is at least a part of the flange 3. Furthermore, the secondary sealing area 32 may also include an area that overlaps (is the same as) the primary sealing area 31. In this embodiment, the secondary sealing area 32 is the entire area of ​​the flange 3.

[0045] The position (height) of the upper surface 30 of the flange portion 3 in the vertical direction is uneven because the flange portion 3 includes the uppermost flange portion 33 or the lower flange portion 34 (see Figure 1B).

[0046] The uppermost part 33 of the flange is the portion whose upper surface is located above the lower surface 340. In this embodiment, the uppermost upper surface 330 of the flange is located, for example, about 1 mm or more above the lower upper surface 340 of the flange. The uppermost part 33 of the flange can support the cover member above the lower upper surface 340 of the flange after the first sealing process and before the second sealing process.

[0047] Specifically, the uppermost part 33 of the flange is a protrusion formed by pressing the flange portion 3 from below towards above. Thus, the upper surface 330 of the uppermost part of the flange protrudes upwards. In this embodiment, the uppermost part 33 of the flange is hollow, but it can also be solid.

[0048] The flange portion 3 of this embodiment is provided with uppermost flange portions 33 of different shapes. Specifically, as shown in FIG1A, the uppermost flange portion 33 includes: a first uppermost flange portion 33A having an elliptical shape when viewed from above; and a second uppermost flange portion 33B having a circular shape when viewed from above. Both the first uppermost flange portion 33A and the second uppermost flange portion 33B are convex portions with a curved shape on the upper surface 330 of the uppermost flange portion. In addition, both the first uppermost flange portion 33A and the second uppermost flange portion 33B are convex portions with a height (dimension in the vertical direction) smaller than the outer diameter when viewed from above.

[0049] Furthermore, in this embodiment, the uppermost flange portion 33 is disposed near the through region 36. For example, at least one of the uppermost flange portions 33 is disposed further inside the through region 36. In this embodiment, all the uppermost flange portions 33 are disposed further inside the through region 36. Specifically, a plurality of uppermost flange portions 33 are disposed inside each through region 36 (e.g., each in a pair). Each uppermost flange portion 33 is disposed inside each through region 36 in such a manner that one is disposed therein. However, after a sealing process, it is preferable to use a plurality of uppermost flange portions 33 to support the cover member, so it is preferable to provide a plurality of them.

[0050] The lower flange portion 34 is the part located below the upper surface. In this embodiment, the lower flange portion 34 is the part other than the uppermost flange portion 33 in the flange portion 3.

[0051] The through region 36 is disposed, for example, at a position opposite to the receiving portion 2. In the case where the flange portion 3 is annular with corners at 4 locations, the through region 36 is preferably formed at 1 location at each corner of the flange portion 3 when viewed from above, for a total of 4 locations. The shape of each through region 36 is preferably the same.

[0052] Furthermore, in this embodiment, the through region 36 is a recessed portion that curves downwards. Additionally, the through region 36 is circular when viewed from above. Specifically, the through region 36 is a recessed portion that curves downwards into a roughly hemispherical shape.

[0053] A groove 360 ​​is further formed in the recess of the through region 36 of this embodiment. Specifically, the upper surface 361 of the through region 36 is recessed downward, and a groove 360 ​​that is recessed downward is provided on the upper surface 361.

[0054] The shape of the groove 360 ​​is, for example, a cross shape that intersects (for example, approximately orthogonally at this lowest point) at the lowest point of the point belonging to the through region 36. In other words, the groove 360 ​​has a shape that radiates outward from the center of the through region 36 when viewed from above. The width of the groove 360 ​​(the dimension in the direction orthogonal to the extension direction of the groove 360) is, for example, 0.5 mm.

[0055] Next, a sterilization method for the object to be treated using the packaging container of the present invention will be described. One embodiment of the sterilization method uses food as the content, and the main steps are, in sequence, a food containing step, a perforation forming step, a primary sealing step, a sterilization step, and a secondary sealing step. More specifically, as shown in FIG3, the steps are, in sequence, a food containing step, a perforation forming step, a primary sealing step, a degassing step, a sterilization step, a cooling step, a gas replacement step, and a secondary sealing step. The steps of this embodiment will be described below. Furthermore, this embodiment of the method will be described using the packaging container 1 of the above embodiment.

[0056] First, as shown in Figures 4A and 4B, after the food containing process of containing food F in packaging container 1, a through-hole forming process is performed. This through-hole forming process involves forming a through-hole 38 through the through-hole region 36 at a location further inside the primary sealing region 31 of the flange portion 3. Food F can be, for example, same-day delivery food, that is, food that has been processed in a food factory or other similar facilities, or any food such as children's processed food.

[0057] As shown in FIG5, the through hole 38 of this embodiment is formed by forming a crack 380 on a portion of the through region 36. In the through hole forming process of this embodiment, the through region 36 is located below the surrounding region when the outer periphery 363 of the through region 36 is continuous with the surrounding region of the through region 36 of the flange portion 3. In other words, the through region 36 is located below the surrounding region of the through region 36 of the flange portion 3, with the outer periphery 363 of the through region 36 as the boundary.

[0058] In the through-hole forming process of this embodiment, the crack 380 is formed by splitting the through region 36 from above. When forming the crack 380, for example, the following method can be used: using a piercing tool (not shown) with a piercing needle at its front end, and piercing the through region 36 with the piercing needle. The piercing needle is guided by the groove 360 ​​provided on the through region 36 and pierces to the lowest point of the through region 36, causing the through region 36 to split along the groove 360. As a result, the through region 36 is divided into four parts with the cross-shaped crack 380 as the boundary.

[0059] Next, as shown in Figures 6A, 6B, and 7, after the initial sealing process of sealing the cover member 5 of the opening 20 of the receiving portion 2 with the initial sealing area 31 of the flange portion 3, a sterilization process is performed. This sterilization process involves allowing heating steam S to flow into the receiving portion 2 via the flow path R formed between the flange portion 3 and the cover member 5, and then exposing the food F to the heating steam S for sterilization (refer to Figure 7). In this embodiment, the initial sealing process is a process of sealing the initial sealing area 31 belonging to the outer periphery of the flange portion 3 with the cover member 5 in a linear manner in the circumferential direction of the outer periphery of the flange portion 3 (refer to Figure 6A). Furthermore, in this initial sealing process, the cover member 5 is heat-fused to the initial sealing area 31, for example, using a heat sealing machine (not shown in the figure).

[0060] In this embodiment, the sterilization process is described using a short-time conditioning sterilization apparatus RIC (hereinafter referred to as RIC) manufactured by Nichisaka Manufacturing Co., Ltd. The short-time conditioning sterilization apparatus RIC (not shown in the figure) here refers to an apparatus that includes: a processing tank capable of holding the containerized food to be processed; a steam supply device for supplying steam to the processing tank; a degassing device for degassing the processing tank to create a vacuum; and a heating device for heating the processing tank.

[0061] In this embodiment, a degassing process is performed on the containing section 2 before the sterilization process. During the degassing process, a plurality of packaging containers 1, each containing food F, are arranged on a tray and sealed with a lid member 5. These containers are then placed in a processing tank constituting the RIC, with multiple sections of the tray overlapping vertically. After sealing the processing tank with its lid, the tank is degassed until a vacuum is reached. While the processing tank is being degassed to a vacuum, the air in the containing section 2 is also degassed via the flow path R, and the containing section 2 becomes vacuum-like, similar to the processing tank.

[0062] In the sterilization process, heating steam S is supplied to the processing tank, and the temperature inside the processing tank is set to, for example, 100°C to 145°C. The heating steam S supplied to the processing tank flows from below the flange portion 3 through the flow path R (through hole 38 and gap C) into the receiving portion 2. Thereby, the food F contained in the receiving portion 2 is sterilized by the heating steam S.

[0063] In this embodiment, a cooling process is performed after the sterilization process to cool the food F. In the cooling process, the pressure inside the aforementioned processing tank is reduced to discharge the heating steam S, and then the processing tank is made into a vacuum state, thereby causing the moisture to evaporate and the latent heat to be removed from the food F, thus cooling the food F.

[0064] Furthermore, after the cooling process, the cover of the aforementioned processing tank is opened and the packaging container 1 containing the food F is removed along with the tray.

[0065] Then, preferably, a gas substitution process is performed. In this gas substitution process, an inert gas such as nitrogen or carbon dioxide is supplied to the containment section 2 via the flow path R.

[0066] The gas substitution process and secondary sealing process of this embodiment are performed while the packaging container 1 is placed in the mold of the heat sealing machine. The mold is provided with a supply path for supplying inert gas through through holes 38 formed in the container body 4 when the packaging container 1 is placed. In the gas substitution process of this embodiment, inert gas is supplied to any one of the four through holes 38 via the supply path of the mold. Furthermore, an air discharge path is also formed in the mold at positions corresponding to the remaining three through holes 38, through which the air compressed within the packaging container 1 by the supplied inert gas is released to the outside.

[0067] As shown in Figures 8A and 8B, after the gas replacement process, a secondary sealing process is performed to seal the cover member 5 with the secondary sealing area 32. This yields a packaged food 6 composed of the packaging container 1, the cover member 5, and the food F.

[0068] The secondary sealing process in this embodiment is a process of sealing the secondary sealing area 32, which belongs to the outer periphery of the flange portion 3, and the cover member 5 in a surface manner. In the secondary sealing process, the cover member 5 is heat-fused to the secondary sealing area 32, for example, by using a heat sealing machine (not shown in the figure).

[0069] In this embodiment, the heat sealing machine includes: a mold (receiving mold) on which the container body 4 is placed and gas replacement is performed, and a mold (heat sealing mold) that presses the cover member 5 from above; since the secondary sealing process is performed quickly after gas replacement, the packaging container is placed on the receiving mold, so the oxygen concentration in the packaging container 1 can be maintained at an extremely low level.

[0070] Since the secondary sealing area 32 of the packaging container 1 is the entire area of ​​the flange portion 3, the entire area of ​​the flange portion 3 is pressurized from the top and bottom during the secondary sealing process, as shown in FIG9. The through hole 38 is closed and the uppermost part 33 of the flange is also crushed, thereby closing the gap C. In the packaging container 1 of this embodiment, although the through hole 38 in the packaging container 1 after secondary sealing is only closed by the cover member 5, during the secondary sealing process, by pressing the entire area of ​​the flange portion 3 from the top and bottom while the flange portion 3 is placed on a mold with a flat upper surface, the through hole 38 in the packaging container 1 after secondary sealing can also be closed by the through area 36 that is deformed (crushed) by the cover member 5. In addition, during the secondary sealing process, the entire area of ​​the flange portion 3 other than the uppermost part 33 of the flange can also be pressurized from the top and bottom. In this case, the gap C is closed while the uppermost part 33 of the flange remains intact without being crushed.

[0071] The above-described packaging container 1 can preferably be used as, for example, a packaging container 1 for packaging food 6, in which food F is contained in the containing portion 2, and a through hole 38 is provided in the through area 36 of the flange portion 3, the cover member 5 is sealed to the primary sealing area 31 of the flange portion 3, and then heated steam S is allowed to circulate in the containing portion 2 through the flow path R to sterilize the food F, and the cover member 5 is sealed to the secondary sealing area 32 of the flange portion 3.

[0072] In this packaging container 1, when a through hole 38 is provided further inside the primary sealing area 31 of the flange portion 3, this through hole 38 constitutes part of the flow path R. Furthermore, when the primary sealing area 31 and the cover member 5 are sealed together, a gap C is generated between the lower flange portion 34 and the cover member 5, and this gap C constitutes part of the flow path R. Therefore, when sterilizing the food F, heating steam S flows from below the flange portion 3 through the flow path R formed by the through hole 38 and the gap C into the receiving portion 2, thereby sterilizing the food F within the receiving portion 2.

[0073] Especially in the packaging container 1, since the uppermost surface 330 of the flange is located above the lower surface 340 of the flange, the uppermost part 33 of the flange maintains the gap C included in the flow path R when sterilizing the food F. Therefore, heating steam S can flow into the receiving part 2 while the uppermost part 33 of the flange reliably maintains the state in which this gap C is not closed.

[0074] Furthermore, in this packaging container 1, the lid member 5 is located above the flow path R, meaning that the flow path R is not exposed on the lid member 5. Therefore, fallen bacteria are unlikely to enter the packaging container 1 through the flow path R. In addition, since the secondary sealing area 32 is constructed by sealing the lid member 5 to close the flow path R, the packaging container 1 can completely seal the food F through the secondary sealing of the lid member 5 and the container body 4.

[0075] In the packaging container 1 of this embodiment, when a crack 380 is formed in a part of the through region 36 to provide a through hole 38 (refer to FIG5), the formation of the through hole 38 will not cause a part of the flange 3 to break, and no fragments of the flange 3 will be generated. Therefore, it is possible to prevent fragments of the flange 3 from being mixed into the receiving part 2.

[0076] Furthermore, in the packaging container 1 of this embodiment, since the through region 36 is a downwardly recessed portion (refer to FIG. 2), when forming the through hole 38, a perforating needle is pierced through this recessed through region 36. This keeps the perforated portion of the through region 36 in a state lower than other areas of the flange portion 3 (refer to FIG. 5), and makes it difficult for it to return from this lower state to the upper state. This prevents the through hole 38 from being closed and maintains the through state of the through hole 38 until the secondary sealing area of ​​the flange portion 3 and the cover member 5 are sealed.

[0077] Furthermore, in the packaging container 1 of this embodiment, since a through area 36 is provided at the position of the receiving part 2 (refer to FIG1A), when a through hole 38 is provided at this position, gas can be allowed to flow through the through hole 38 from both sides of the receiving part 2 (refer to FIG4A), which can suppress uneven heating of the food F.

[0078] The container body 4 and lid member 5 used in this embodiment preferably have a gas barrier layer. That is, the container body 4 and lid member 5 are preferably composed of a multi-layer structure including at least one oxygen barrier layer. By providing a gas barrier layer to the container body 4 and lid member 5, the proliferation of aerobic bacteria after sterilization is more effectively suppressed, thus further extending the quality retention period achieved in each embodiment. The aforementioned gas barrier layer may be an oxygen barrier layer.

[0079] The oxygen barrier layer is a layer that prevents gas penetration. For example, under conditions of 20°C and 65%RH, the oxygen penetration rate measured according to JIS-K7126-2 (2006) Part 2 (Isobaric Method) is 100cc. 20μm / (m2.day.atm) or less, preferably 50cc. 20μm / (m2.day.atm) or less, and even more preferably 10cc. The oxygen penetration rate of "10cc. 20μm / (m2.day.atm)" here means that in a 20μm barrier material (meaning the case where it is composed solely of an oxygen barrier layer), the oxygen penetration amount per day at 1 atmosphere of oxygen is 10cc.

[0080] The aforementioned oxygen barrier layer includes, for example, gas barrier materials such as: ethylene-vinyl alcohol copolymer (hereinafter also referred to as "EVOH (Ethylene Vinyl Alcohol Copolymer)"), composite structures containing phosphorus and polyvalent metal elements, processed starch, polyamide, polyester, polyvinyl chloride, acrylonitrile copolymer, polyvinyl fluoride, polyvinyl chloride, polyvinyl alcohol, inorganic layered compounds, inorganic vapor-deposited layers, and metal foils. Especially from the perspective of having good oxygen barrier properties and melt-forming properties, the aforementioned oxygen barrier layer preferably contains EVOH, polyamide, and processed starch, or a combination thereof; and from the perspective of having particularly excellent melt-forming properties, it is particularly preferred to contain EVOH.

[0081] (EVOH)

[0081] EVOH can be obtained, for example, by saponifying an ethylene-vinyl ester copolymer. The manufacture and saponification of the ethylene-vinyl ester copolymer can be carried out by methods generally known. Examples of ethylene esters that can be used in this method include: vinyl acetate, vinyl formate, vinyl propionate, trimethylvinyl acetate, and ethylene tert-carbonate, etc., which are fatty acid ethylene esters.

[0082] In this invention, the ethylene unit content of the EVOH is preferably, for example, 20 mol% or more, 22 mol% or more, or 24 mol% or more. Furthermore, the ethylene unit content of the EVOH is preferably, for example, 60 mol% or less, 55 mol% or less, or 50 mol% or less. When the ethylene unit content is 20 mol% or more, its melt formability and oxygen barrier properties at high temperatures tend to improve. When the ethylene unit content is 60 mol% or less, its oxygen barrier properties tend to improve. The ethylene unit content in this EVOH can be determined, for example, by nuclear magnetic resonance (NMR).

[0083] In this invention, the degree of saponification of the ethylene ester component of EVOH is preferably, for example, 80 mol% or more, 90 mol% or more, or 99 mol% or more. By making the degree of saponification 80 mol% or more, the oxygen barrier properties of the aforementioned oxygen barrier layer can be improved, for example. On the other hand, the degree of saponification of the ethylene ester component of EVOH can be, for example, 100% or less or 99% or less. The degree of saponification of EVOH can be calculated by measuring the peak area of ​​hydrogen atoms contained in the ethylene ester structure and the peak area of ​​hydrogen atoms contained in the vinyl alcohol structure using 1H-NMR. By making the degree of saponification of EVOH within the above range, good oxygen barrier properties can be provided to the oxygen barrier layer constituting the container body 4 or the lid member 5.

[0084] Furthermore, without hindering the purpose of the present invention, EVOH may contain units derived from monomers other than ethylene and ethylene esters and their saponifications. When EVOH contains other monomer units, the content of these other monomer units relative to the total structural units of EVOH is, for example, 30 mol% or less, 20 mol% or less, 10 mol% or less, or 5 mol% or less. Furthermore, when EVOH contains units derived from these other monomers, the content is, for example, 0.05 mol% or more, or 0.1 mol% or more.

[0085] Other monomers that such EVOH may contain include, for example, olefins such as propylene, butene, pentene, and hexene; 3-acetoxy-1-propene, 3-acetoxy-1-butene, 4-acetoxy-1-butene, 3,4-diacetoxy-1-butene, 3-acetoxy-4-methyl-1-butene, 4-acetoxy-1-butene, and 3,4-acetoxy-1-butene. -1-Butene, 3-Acryloyloxy-4-methyl-1-butene, 4-Acryloyloxy-2-methyl-1-butene, 4-Acryloyloxy-3-methyl-1-butene, 3,4-Diacryloyloxy-2-methyl-1-butene, 4-Acryloyloxy-1-pentene, 5-Acryloyloxy-1-pentene, 4,5-Diacryloyloxy-1-pentene, 4-Acryloyloxy-1-hexene, 5-Acryloyloxy 1-Hexene, 6-acetoxy-1-hexene, 5,6-diacetoxy-1-hexene, 1,3-diacetoxy-2-methylenepropane and other ester-containing alkenes or their saponifications; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, and isoconic acid or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; acetylamines such as acrylamide and methacrylamide; olefinic sulfonic acids such as vinylsulfonic acid, allylsulfonic acid, and methylallylsulfonic acid or their salts; vinyl silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxy-ethoxy)silane, and γ-methacryloxypropyltrimethoxysilane; alkyl vinyl ethers, vinyl ketones, N-vinylpyrrolidone, vinyl chloride, and vinylidene chloride.

[0086] EVOH can be modified EVOH through methods such as carbamate, ketalization, cyanoethylation, or oxidative olefination. EVOH modified in this way tends to improve the melt-forming properties of the aforementioned oxygen barrier layer.

[0087] EVOH can also be used in combination with two or more EVOHs that have different ethylene unit contents, saponification degree, copolymer composition, whether they are modified or of different types.

[0088] EVOH can be obtained by commonly known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In one embodiment, bulk polymerization or solution polymerization, which can be carried out in a solvent-free solution or alcohol, is used.

[0089] There are no particular limitations on the solvent used in solution polymerization. For example, it can be an alcohol, preferably a lower alcohol such as methanol, ethanol, or propanol. The amount of solvent in the polymerization reaction solution can be selected by considering the viscosity, average degree of polymerization of the target EVOH, or the chain transfer of the solvent. The mass ratio of solvent to total monomer in the reaction solution (solvent / total monomer) is, for example, 0.01 to 10, preferably 0.05 to 3.

[0090] In addition, the catalysts used in the above polymerization can be listed as azo-based initiators such as 2,2-azobisisobutyronitrile, 2,2-azobis-(2,4-dimethylpentanonitrile), 2,2-azobis-(4-methoxy-2,4-dimethylpentanonitrile), and 2,2-azobis-(2-cyclopropylpropionitrile); and organic peroxide-based initiators such as isobutyl peroxide, isopropylphenyl peroxyneodecanate, diisopropylperoxycarbonate, di-n-propylperoxydicarbonate, tributylperoxyneodecanate, lauryl peroxide, benzoyl peroxide, and tributyl hydroperoxide.

[0091] The polymerization temperature is preferably from 20°C to 90°C, and more preferably from 40°C to 70°C. The polymerization time is preferably from 2 hours to 15 hours, and more preferably from 3 hours to 11 hours. The polymerization rate relative to the added ethylene ester is preferably from 10% to 90%, and more preferably from 30% to 80%. The resin content in the solution after polymerization is preferably from 5% to 85%, and more preferably from 20% to 70%.

[0092] In the above polymerization, after polymerization for a predetermined time or after reaching a predetermined polymerization rate, a polymerization inhibitor may be added as needed and unreacted ethylene gas may be evaporated to remove unreacted ethylene ester.

[0093] Next, an alkaline catalyst is added to the copolymer solution to saponify the copolymer. Both continuous and batch saponification methods can be used. Examples of alkaline catalysts that can be added include sodium hydroxide, potassium hydroxide, and alcoholic alkali metals.

[0094] The EVOH after the saponification reaction contains alkaline catalysts, derivative salts such as sodium acetate or potassium acetate, and other impurities. Therefore, it is preferable to neutralize or wash as needed to remove these catalysts, salts, and impurities. Here, when washing the EVOH after the saponification reaction with water that is almost free of predetermined ions (e.g., metal ions, chloride ions), such as ion-exchanged water, it is also possible to partially remove the derivative salts such as sodium acetate or potassium acetate, leaving some residue.

[0095] EVOH may also contain other thermoplastic resins, metal salts, acids, boron compounds, plasticizers, fillers, anti-caking agents, lubricants, stabilizers, surfactants, colorants, UV absorbers, anti-static agents, desiccants, crosslinking agents, reinforcing materials such as various fibers, and other components. Considering the aforementioned reasons for the good thermal stability of the oxygen barrier layer or its adhesion to other resins, it is preferable to contain metal salts and acids.

[0096] From the perspective of improving interlayer adhesion, the aforementioned metal salt is preferably an alkali metal salt, and from the perspective of improving thermal stability, it is preferably an alkaline earth metal salt. When the EVOH contains a metal salt, the content relative to the EVOH, calculated using the metal atoms of the metal salt, is, for example, 1 ppm or more, 5 ppm or more, 10 ppm or more, or 20 ppm or more. Furthermore, when the EVOH contains a metal salt, the content relative to the EVOH, calculated using the metal atoms of the metal salt, is, for example, 10000 ppm or less, 5000 ppm or less, 1000 ppm or less, or 500 ppm or less. By keeping the metal salt content within the range defined by the aforementioned lower and upper limits, the interlayer adhesion of the aforementioned oxygen barrier layer is well maintained, and the thermal stability of the EVOH is well maintained when the recovery container body 4 is in use.

[0097] Examples of the aforementioned acids include carboxylic acid compounds and phosphoric acid compounds. These acids are useful from the viewpoint of improving the thermal stability of EVOH during melt molding. When EVOH contains carboxylic acid compounds, the content of carboxylic acid (i.e., the content of carboxylic acid in the dried composition of the oxygen barrier layer containing EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 50 ppm or more. Furthermore, the content of carboxylic acid compounds is, for example, 10,000 ppm or less, 1,000 ppm or less, or 500 ppm or less. When EVOH contains phosphoric acid compounds, the content of phosphoric acid (i.e., the phosphate conversion content of the phosphoric acid compound in the oxygen barrier layer containing EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 30 ppm or more. Furthermore, the content of phosphoric acid compounds is, for example, 10,000 ppm or less, 1,000 ppm or less, or 300 ppm or less. By including carboxylic acid compounds or phosphoric acid compounds in EVOH within the above-mentioned ranges, there is a tendency for the thermal stability of EVOH during melt molding to become better.

[0098] When EVOH contains the aforementioned boron compounds, the content (i.e., the boron equivalent content of the boron compounds in the dried composition of the oxygen barrier layer containing EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 50 ppm or more. Furthermore, the content of the boron compounds is, for example, 2000 ppm or less, 1000 ppm or less, or 500 ppm or less. By including boron compounds or phosphoric acid compounds in EVOH within the aforementioned range, there is a tendency for the thermal stability of EVOH to improve during melt molding.

[0099] The method for containing the aforementioned carboxylic acid compound, phosphoric acid compound, or boron compound in the oxygen barrier layer containing EVOH is not particularly limited. For example, these compounds can be added during the granulation of the composition containing EVOH for mixing. The method of adding the aforementioned carboxylic acid compound, phosphoric acid compound, or boron compound is not particularly limited, and examples include: adding it in the form of a dry powder, adding it in a paste state impregnated with a predetermined solvent, adding it in a state suspended in a predetermined liquid, adding it by dissolving it in a predetermined solvent as a solution, and impregnating it in a predetermined solution. In particular, considering that these compounds can be uniformly dispersed in EVOH, it is preferable to use the method of adding it by dissolving it in a predetermined solvent as a solution or the method of impregnating it in a predetermined solution. The solvent used in such methods is not particularly limited, but considering the solubility, cost, ease of handling, and safety of the working environment of the compounds added as additives, water is preferred.

[0100] When the oxygen barrier layer in the multilayer structure contains EVOH as a main component, the ratio of EVOH in the oxygen barrier layer is, for example, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. Here, the term "main component of the oxygen barrier layer" as used in this specification means the component that has the largest mass percentage among the components constituting the oxygen barrier layer.

[0101] When the oxygen barrier layer in the multilayer structure contains EVOH as a main component, the average thickness of the oxygen barrier layer is, for example, 3 μm or more, 5 μm or more, or 10 μm or more. Furthermore, the average thickness of the oxygen barrier layer is, for example, 100 μm or less or 50 μm or less. Here, the term "average thickness of the oxygen barrier layer" as used in this specification refers to the total thickness of all the aforementioned oxygen barrier layers containing EVOH as a main component in the multilayer structure, divided by the number of layers of the oxygen barrier layer. By ensuring that the average thickness of the oxygen barrier layer is within the above-mentioned range, the durability, flexibility, and appearance characteristics of the container body 4 or the cap member 5 constituting the packaging container of the present invention tend to improve.

[0102] (A complex structure containing phosphorus and polyvalent metal elements)

[0102] The composite structure system containing phosphorus and polyvalent metal elements has a barrier layer formed by reacting a phosphorus compound with a polyvalent metal compound. This structure can be formed by mixing a solution containing a phosphorus compound with a solution or dispersion containing a polyvalent metal compound to prepare a coating agent, and then applying the coating agent to a substrate to allow the polyvalent metal compound to react with the phosphorus compound. Here, M represents the polyvalent metal atom, and a bond represented by MOP is formed between the polyvalent metal atom M and the phosphorus atom. The characteristic absorption band of the MOP bond in the infrared absorption spectrum can be observed in the region from 1080 cm⁻¹ to 1130 cm⁻¹. In the infrared absorption spectrum of this composite structure, the maximum absorption wavenumber in the region from 800 cm⁻¹ to 1400 cm⁻¹ is preferably located in the range of 1080 cm⁻¹ to 1130 cm⁻¹. When the maximum absorption wavenumber of the composite structure is within the above range, the composite structure system tends to have excellent oxygen barrier properties.

[0103] The substrate to which the coating agent is applied is not particularly limited, and examples include: resins such as thermoplastic resins and thermosetting resins; fibrous aggregates such as fabrics and paper; wood; glass, etc. Thermoplastic resins and fibrous aggregates are particularly preferred, and thermoplastic resins are especially preferred. The form of the substrate is not particularly limited, and it can be a layer such as a film or sheet. The substrate is particularly preferably composed of a thermoplastic resin film and paper, and is even more preferably a thermoplastic resin film. The thermoplastic resin film is preferably polyester, and polyethylene terephthalate is especially preferred from the perspective of imparting good mechanical strength to the composite structure.

[0104] Any polyvalent metal element that can react with phosphorus compounds of two or more molecules is acceptable; there are no special restrictions, and any element can be used. For example, a polyvalent metal element can be a hemipolyvalent metal element. Examples of polyvalent metal elements include: magnesium, calcium, zinc, aluminum, silicon, titanium, zirconium, etc., with aluminum being particularly preferred.

[0105] Any compound containing a polyvalent metal element is acceptable as long as it can react with a phosphorus compound to form a complex structure; there are no particular limitations, and any compound can be used. Furthermore, polyvalent metal compounds can be used as solutions dissolved in solvents or as dispersions to disperse polyvalent metal compound particles in solvents. For example, an aqueous solution containing aluminum nitrate as a polyvalent metal compound can be used.

[0106] Furthermore, the polyvalent metal compound particles can also be dispersed in water or an aqueous solvent to be used as a dispersion. This dispersion is preferably a dispersion of alumina particles. Generally, the polyvalent metal oxide particles have hydroxyl groups on their surface, and due to the presence of these hydroxyl groups, they can react with the aforementioned phosphorus compounds to form the aforementioned bonds. The polyvalent metal oxide particles can be synthesized, for example, from compounds with hydrolyzable characteristic groups bonded to metal atoms, by hydrolyzing and condensing the hydrolysis products. Examples of raw materials include aluminum chloride, triacetylene oxide, and isopropyl alumina. Methods for condensing the aforementioned hydrolysis products include, for example, liquid-phase synthesis methods such as the sol-gel method. Furthermore, the polyvalent metal oxide particles preferably have, for example, spherical, flat, polyhedral, fibrous, or needle-like morphologies; from the perspective of improving oxygen barrier properties, fibrous or needle-like morphologies are preferred. Furthermore, in order to improve oxygen barrier properties and transparency, the average particle size of polyvalent metal oxide microparticles is preferably between 1 nm and 100 nm.

[0107] Any phosphorus compound is acceptable as long as it can react with a compound of a polyvalent metal to form the aforementioned bonds; there are no particular limitations, and any phosphorus compound may be used. Examples of phosphorus compounds include phosphoric acid compounds and their derivatives. Specific examples include: phosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid. Among the aforementioned polyphosphoric acids, polyphosphoric acid formed by the condensation of pyrophosphate, triphosphate, or four or more phosphoric acids may be included. In addition, derivatives of phosphoric acid compounds may include: phosphates, esters (e.g., trimethyl phosphate), halides, and dehydrated products (e.g., phosphorus pentoxide).

[0108] This phosphorus compound can be used as a solution, for example as an aqueous solution with water as a solvent, or as a solution containing a hydrophilic organic solvent such as a lower alcohol solution.

[0109] The coating agent can be obtained by mixing a solution or dispersion of a polyvalent metal compound and a solution of a phosphorus compound. Other components may be added to the above coating agent. Examples of other components include: polymers, metal complexes, viscosity compounds, crosslinking agents, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, etc. Examples of polymers include: polyvinyl alcohol, partially saponified polyvinyl acetate, poly(meth)acrylate, polysaccharides (e.g., starch), acrylic polymers (e.g., polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymers) and their salts, ethylene-vinyl alcohol copolymers, ethylene-maleic anhydride copolymers, styrene-maleic anhydride copolymers, isobutylene-maleic anhydride alternating copolymers, ethylene-acrylic acid copolymers, saponified ethylene-ethyl acrylate copolymers, etc.

[0110] For example, the coated film obtained by coating the above-mentioned coating agent and drying off the solvent is subjected to heat treatment, thereby causing the polyvalent metal compound and the phosphorus compound to react and form the above-mentioned bonds, thus forming a composite structure containing phosphorus and polyvalent metal elements. The temperature used for heat treatment is preferably 110°C or higher, more preferably 120°C or higher, even more preferably 140°C or higher, and particularly preferably 170°C or higher. At lower temperatures, more time is required to form sufficient bonds, sometimes reducing productivity. The upper limit of the temperature used for heat treatment varies depending on the type of substrate film, for example, 240°C or 220°C. Furthermore, the time required for heat treatment is, for example, 0.1 seconds or more, 1 second or more, or 5 seconds or more. Furthermore, the time required for heat treatment is, for example, less than 1 hour, less than 15 minutes, or less than 5 minutes. Such heat treatment can be carried out in any environment, including atmospheric, nitrogen, or argon atmospheres.

[0111] The lower limit of the average thickness of a single layer of an oxygen barrier layer containing a composite structure of phosphorus and polyvalent metal elements as the main component is, for example, 0.05 μm or more or 0.1 μm or more. The average thickness of a single layer of an oxygen barrier layer containing a composite structure of phosphorus and polyvalent metal elements as the main component is, for example, 4 μm or less or 2 μm or less. The term "average thickness of a single layer of an oxygen barrier layer containing a composite structure of phosphorus and polyvalent metal elements as the main component" as used in this specification means the total thickness of all oxygen barrier layers containing the aforementioned composite structure as the main component in a multilayer structure divided by the number of such oxygen barrier layers. When the average thickness of a single layer of the oxygen barrier layer is less than the aforementioned lower limit, it is difficult to form a layer of uniform thickness, which may sometimes reduce the durability of the resulting multilayer structure. When the average thickness of a single layer of the oxygen barrier layer is greater than the aforementioned upper limit, the flexibility, tensile strength, and thermal stability of the resulting multilayer structure may sometimes decrease.

[0112] (Processing starch)

[0112] There are no particular limitations on the starch used as a raw material for starch processing. Examples include starches derived from wheat, corn, cassava, potato, rice, oats, kudzu root starch, and peas. High-amylose starch is preferred, especially high-amylose corn starch and high-amylose cassava starch.

[0113] Processed starch is preferably chemically modified by substituting the hydroxyl groups with functional groups of ethers, esters, or combinations thereof. Processed starch is preferably modified by containing a hydroxyalkyl group having 2 to 6 carbon atoms, or by reacting with a carboxylic anhydride. When processed starch is modified by containing a hydroxyalkyl group having 2 to 6 carbon atoms, it is preferable to have a functional group having 2 to 4 carbon atoms as a substituent, for example, preferably a hydroxyethyl or hydroxybutyl group capable of generating a hydroxyether substituent. Furthermore, when processed starch is modified by reacting with a carboxylic anhydride, the functional group is preferably a butyrate ester or a lower homologue, more preferably an acetate ester. For the manufacture of ester derivatives, dicarboxylic anhydrides such as maleic acid, phthalic acid, or octenyl succinic anhydride may also be used.

[0114] The processed starch is preferably hydroxypropylated amylose containing hydroxypropyl groups, and even more preferably hydroxypropylated high amylose.

[0115] The degree of substitution of processed starch is expressed as the average number of substituents per unit of anhydrous glucose, usually with a maximum value of 3. The degree of substitution of the above-mentioned processed starch is preferably 0.05 or higher and less than 1.5.

[0116] Processed starch may also contain other starches. Other starches include, for example, mixtures of high-amylose and low-amylose starches.

[0117] Processed starch may also contain water. Water can function as a plasticizer relative to processed starch. The water content is, for example, less than 20% by mass or less than 12% by mass. The moisture content of an oxygen barrier layer with processed starch as the main component is generally the equilibrium moisture content in the relative humidity of the operating environment.

[0118] Processed starch may also contain one or more water-soluble polymers. The water-soluble polymer is not particularly limited; examples include polyvinyl acetate, polyvinyl alcohol, or combinations thereof. Polyvinyl alcohol is particularly preferred. The content of one or more water-soluble polymers is, for example, 20% by mass or less or 12% by mass or less. Furthermore, the content of one or more water-soluble polymers is, for example, 1% by mass or more or 4% by mass or more.

[0119] Processed starch may also contain one or more plasticizers. There are no particular limitations on the plasticizer, but polyols are preferred. Examples of polyols include sorbitol, glycerol, maltitol, xylitol, and combinations thereof. The content of one or more plasticizers in processed starch is, for example, 20% by mass or less or 12% by mass or less.

[0120] Processed starch may also contain lubricants. Examples of lubricants include fatty acids with 12 to 22 carbon atoms, fatty acid salts with 12 to 22 carbon atoms, and combinations thereof. The content of lubricants in processed starch is, for example, 5% by mass or less.

[0121] The average thickness of a single layer of oxygen barrier layer containing processed starch as the main component is, for example, 10 μm or more or 100 μm or more. The average thickness of a single layer of oxygen barrier layer containing processed starch as the main component is, for example, 1000 μm or less or 800 μm or less. The term "average thickness of a single layer of oxygen barrier layer containing processed starch as the main component" as used in this specification means the total thickness of all the aforementioned oxygen barrier layers containing processed starch as the main component in the multilayer structure divided by the number of such oxygen barrier layers. When the average thickness of a single layer of oxygen barrier layer is less than the aforementioned lower limit, it is difficult to form a layer of uniform thickness, which may sometimes reduce the durability of the obtained multilayer structure. When the average thickness of a single layer of oxygen barrier layer is greater than the aforementioned upper limit, the flexibility, tensile strength, and thermal stability of the obtained multilayer structure may sometimes decrease.

[0122] (Inorganic layered compound)

[0122] The barrier layer containing inorganic layered compounds is, for example, a layer that exhibits barrier properties due to the inorganic layered compounds when the inorganic layered compounds are dispersed in a thermoplastic resin. The thermoplastic resin used in the barrier layer containing inorganic layered compounds is not particularly limited, and examples include polyamide, ethylene-vinyl alcohol copolymer, etc.

[0123] Inorganic layered compounds include: bentonite, clay, Montmorillonite, Smectite, hydrotalcite, etc. In addition, inorganic layered compounds can also be organically modified inorganic layered compounds that have undergone organic treatment.

[0124] Inorganic layered compounds, for example, are composed of plate-like crystals and have any appearance, such as round, non-round, elliptical, roughly oblong, or roughly cocoon-shaped. The average length of the long side of the plate-like crystals of the inorganic layered compound, which can be measured by an electron microscope, preferably meets a predetermined range.

[0125] The average length of the long side of the inorganic layered compound is preferably 70 nm or more, particularly 80 nm or more, and even more preferably 90 nm or more. The inorganic layered compound is aligned within the film surface by the stress generated during stretching. However, when the average length of the long side of the inorganic layered compound is less than 70 nm, the degree of alignment is insufficient, and sometimes sufficient oxygen permeability cannot be obtained. On the other hand, the average length of the long side of the inorganic layered compound can be less than 2000 nm.

[0126] Furthermore, the inorganic layered compound preferably does not contain coarse material with a thickness exceeding 2 μm. When the inorganic layered compound contains coarse material with a thickness exceeding 2 μm, the transparency or stretchability may sometimes decrease.

[0127] The content of inorganic layered compound in the barrier layer containing inorganic layered compound is preferably 0.3 to 20% by mass, based on the mass of the barrier layer.

[0128] (Inorganic vapor deposition layer)

[0128] The inorganic vapor-deposited layer is, for example, a barrier layer obtained by vapor-depositing an inorganic material onto a substrate. Examples of substrates that can constitute the inorganic vapor-deposited layer include: resins such as thermoplastic resins and thermosetting resins; fibrous aggregates such as fabrics and paper; wood; and glass. Thermoplastic resins and fibrous aggregates are preferred, and thermoplastic resins are particularly preferred. When the substrate is composed of the aforementioned resins, the layered form, such as a film or sheet, is preferred.

[0129] Examples of thermoplastic resins used in the substrate include: polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate (PET), polyethylene 2,6-naphthalate, polybutylene terephthalate, or copolymers thereof; polyamide resins such as nylon-6, nylon-66, and nylon-12; hydroxyl-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers; polystyrene; poly(meth)acrylate; polyacrylonitrile; polyvinyl acetate; polycarbonate; polyacrylate; regenerated cellulose; polyimide; polyetherimide; polyurethane; polyether ether ketone; ionomer resins, etc. Preferably, at least one thermoplastic resin is selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, nylon-6, and nylon-66.

[0130] When using a film made of thermoplastic resin as the substrate, the substrate can be either a stretched film or a non-stretched film. From the perspective of superior processability (printing, lamination, etc.) of the resulting multilayer structure, a stretched film is preferred, and a biaxially stretched film is particularly preferred. The biaxially stretched film can be a biaxially stretched film manufactured by any one of the following methods: simultaneous biaxial stretching, successive biaxial stretching, and tubular stretching.

[0131] The types of paper that can be used as substrates include, for example: kraft paper, woodfree paper, molding paper, cellophane, parchment paper, synthetic paper, whiteboard paper, grey-backed whiteboard paper, milk carton base paper, paper cup base paper, ivory paper, etc.

[0132] When the substrate is layered, the thickness is preferably 1 μm to 1,000 μm, more preferably 5 μm to 500 μm, and even more preferably 9 μm to 200 μm, in view of the good mechanical strength and processability of the resulting multilayer structure.

[0133] Examples of inorganic materials include: metals such as aluminum, tin, indium, nickel, titanium, and chromium; metal oxides such as silicon oxide and aluminum oxide; metal nitrides such as silicon nitride; metal oxynitrides such as silicon oxynitride; and metal carbonitrides such as silicon carbonitride. From the perspective of excellent barrier properties against oxygen or water vapor, an inorganic vapor-deposited layer formed from any one of aluminum, aluminum oxide, silicon oxide, magnesium oxide, and silicon nitride, or a combination thereof, is preferred.

[0134] There is no particular limitation on the method for forming inorganic vapor deposition layers. For example, physical vapor deposition methods such as vacuum evaporation (e.g., resistance heating evaporation, electron beam evaporation, molecular beam epitaxy, etc.), ion electroplating, sputtering (dual magnetron sputtering, etc.); chemical vapor deposition methods such as thermochemical vapor deposition (e.g., catalytic chemical vapor deposition), photochemical vapor deposition, plasma chemical vapor deposition (e.g., capacitive coupling plasma, inductively coupled plasma, surface wave plasma, electron magnetoresistive resonance plasma, etc.), atomic layer deposition, and organometallic vapor deposition.

[0135] The thickness of the inorganic vapor deposition layer varies depending on the type of components constituting the inorganic vapor deposition layer, preferably from 0.002 μm to 0.5 μm, more preferably from 0.005 μm to 0.2 μm, and even more preferably from 0.01 μm to 0.1 μm. Within this range, a thickness that results in good barrier properties and mechanical properties for the multilayer structure can be selected. When the thickness of the inorganic vapor deposition layer is less than 0.002 μm, the reproducibility of the barrier properties of the inorganic vapor deposition layer against oxygen and water vapor tends to decrease, and there may be cases where the inorganic vapor deposition layer does not exhibit sufficient barrier properties. Furthermore, when the thickness of the inorganic vapor deposition layer exceeds 0.5 μm, the barrier properties of the inorganic vapor deposition layer tend to decrease easily when the multilayer structure is stretched or bent.

[0136] (metal foil)

[0136] A metal foil is a single-layer or multi-layer structure made of a metal with excellent ductility. For example, aluminum can be included as a metal in a metal foil. The metal foil may be in the form of aluminum foil or aluminum strip.

[0137] According to the above-mentioned packaging container with oxygen barrier layer, oxygen intrusion can be prevented and the quality of the sterilized contents contained therein can be maintained for a longer period of time.

[0138] The packaging container of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the composition of other embodiments can be added to the composition of a certain embodiment. In addition, a part of the composition of a certain embodiment can be replaced by the composition of other embodiments. Furthermore, a part of the composition of a certain embodiment can be deleted.

[0139] In the above embodiments, the uppermost flange portions 33A and 33B are both protrusions with a height (dimension in the vertical direction) smaller than the outer diameter when viewed from above, but this is not a limitation. As shown in Figures 10 and 11, it is also possible to provide a third flange uppermost portion 33C with a height approximately equal to the outer diameter when viewed from above in the flange portion 3. The third flange uppermost portion 33C is circular when viewed from above.

[0140] The through hole 38 in the above embodiment is formed by piercing the through region 36 of the flange portion 3 with a piercing needle (that is, the through region 36 is broken), but it is not limited to this. For example, the through hole 38 can be formed by punching through the through region 36 of the flange portion 3.

[0141] As shown in Figures 12A and 12B, when the through-hole 38 is formed by punching the through-area 36 of the flange portion 3 in the through-hole forming process, the through-area 36 is removed from the flange portion 3. In this configuration, from the time the through-hole forming process is performed until the sealing of the secondary sealing area 32 is performed, the flow of gas into the through-hole 38 is not hindered by the through-area 36, ​​so the heating steam S can flow smoothly in the through-hole 38.

[0142] In the packaging container 1 of the above embodiment, the uppermost flange portion 33 is located inside the through region 36, and the primary sealing region 31 is located outside the through region 36. That is, the uppermost flange portion 33 is separate from the primary sealing region 31, but the uppermost flange portion 33 can also serve as the primary sealing region 31. Since the primary sealing region 31 must be located outside the through region 36, in this configuration, at least one of the plurality of uppermost flange portions 33 is located outside the through region 36. For example, the uppermost flange portion 33 can be considered to have a fourth uppermost flange portion 33D, which is located outside the through region 36 and also serves as the primary sealing region 31.

[0143] The uppermost part 33 of the flange may also be the uppermost part 33D of the fourth flange, which is a rib. Furthermore, the upper surface (upper surface 330 of the uppermost part of the flange) of the uppermost part 33 may also be a flat surface, like the upper surface of the uppermost part 33D of the fourth flange (refer to FIG12B). In the case where the uppermost part 33 of the flange is a rib, it may be continuously provided in the circumferential direction of the opening edge 21, for example. Specifically, it is conceivable that the uppermost part 33 of the flange is a rib continuously provided in the circumferential direction of the opening edge 21.

[0144] In the packaging container 1 of the above embodiment, the secondary sealing area 32 is provided in the entire area of ​​the flange portion 3, but it may also be provided in a part of the flange portion 3. In the above-mentioned configuration where the uppermost part 33 of the flange also serves as the primary sealing area 31 (refer to Figures 12A and 12B), as shown in Figures 13A and 13B which illustrate the state after the secondary sealing process, it can be considered that the area in the lower part 34 of the flange located further inside than the primary sealing area 31 is also used as the secondary sealing area 32.

[0145] Furthermore, in the packaging container 1 of the above embodiment, a surface seal is performed in the secondary sealing process; however, a continuous line seal can also be performed in the circumferential direction of the opening edge 21. For example, as shown in Figures 14A and 14B, a line seal can be performed. In this case, the secondary sealing area 32 can be considered as an upwardly protruding ridge.

[0146] Furthermore, in this case, the upper surface of the secondary sealing region 32 is located below the uppermost upper surface 330 of the flange (which also serves as the uppermost upper surface 33D of the fourth flange, which is also used as the primary sealing region 31). Moreover, when the cover member 5 and the primary sealing region 31 are sealed, the flange portion 3 is configured such that a gap C is formed between the upper surface of the secondary sealing region 32 and the lower surface of the cover member 5. In this way, from the time the primary sealing process is performed until the secondary sealing process is performed, that is, when the food F is sterilized, a gap C is generated between the cover member 5 supported by the uppermost upper surface 330 of the flange and the lower upper surface 340 of the flange. The upper surface 230 of the first flange maintains this gap C and reliably keeps the gap C from being closed, thereby allowing the heating steam S to flow into the receiving portion 2 through the flow path R.

[0147] In the above embodiment, a protrusion like the uppermost part 33 of the flange is provided on the flange portion 3. However, a recessed portion that extends downwards may also be provided, or as shown in Figures 15A and 15B, a groove portion 39 is provided on the flange portion 3 as the lower part 34 of the flange. For example, the groove portion 39 may be continuous along the opening edge 21 in the circumferential direction. Specifically, the groove portion 39 is continuous along the entire circumference of the opening edge 21.

[0148] In a configuration where a recess is provided in the flange portion 3, a through region 36 may be provided in this recess. For example, a through region 36 may be provided in the groove portion 39 of the flange portion 3. Specifically, a through region 36 may be provided on a pair of opposite sides separated by the receiving portion 2 in a groove portion 39 that is continuous throughout the circumference of the opening edge 21. In this case, the through regions 36 provided on each side are, for example, positioned opposite each other separated by the receiving portion 2. In this configuration, during the through hole forming process, a through hole 38 is provided in the groove portion 39 of the flange portion 3.

[0149] Furthermore, in this case, it is possible to consider that the primary sealing region 31 is continuously provided on the outer side of the groove 39 of the flange portion 3 (the uppermost part of the flange 33) in the circumferential direction of the opening edge 21. Specifically, it is possible that the primary sealing region 31 is continuous throughout the entire circumference in the circumferential direction of the opening edge 21.

[0150] In the above-described configuration where a through region 36 is provided in the groove 39 of the flange portion 3 (refer to Figures 15A and 15B), as shown in Figures 16A and 16B, the secondary sealing region 32 can be considered to be continuously provided along the opening edge 21 in the circumferential direction on the inner side of the groove 39 of the flange portion 3. Specifically, the secondary sealing region 32 can be considered to be continuous along the entire circumference of the opening edge 21. In the flange portion 3 configured as described above, the groove 39 with the through region 36 is provided inside the primary sealing region 31, and then the secondary sealing region 32 is provided inside the groove 39.

[0151] Furthermore, the through region 36 may also be provided only at one of the corners of the flange portion 3. For example, as shown in FIG17A, the through region 36 may also be provided only in one pair at the corners of the flange portion 3, separated by the receiving portion 2. In this case, as shown in FIG17B, the through hole 38 is provided only at one pair of corners of the flange portion 3, separated by the receiving portion 2.

[0152] Furthermore, the uppermost part 33 of the flange may also be the fifth uppermost part 33E of the flange, which is a hemispherical-shaped hillock. The uppermost part 33 of the flange may also be other shapes such as conical, conical trapezoidal, cylindrical, polygonal columnar, polygonal hammer, etc.

[0153] The base plate 22 of the receiving part 2 in the above embodiment is generally rectangular, but it is also possible to consider it as generally square. In addition to being square, the base plate 22 can also be other polygonal or circular shapes.

[0154] In the packaging container 1 of the above embodiment, a through area 36 is provided in the flange portion 3 and a through hole 38 is provided in the flange portion 3 by performing a through hole forming process. However, it is also possible not to provide a through area 36 in the flange portion 3. This configuration can be considered in the configurations of Figures 18 to 21, etc.

[0155] For example, as shown in Figures 18A and 18B, the flange portion 3 may have a primary sealing region 31 that is sealed with the cover member 5 in a primary sealing process, and is configured such that when the cover member 5 and the primary sealing region 31 are sealed, a flow path R is formed between the flange portion 33 and the cover member 5, allowing gas to flow between the outside and the containment portion 2. In this configuration, the uppermost part 33 of the flange portion 3 is a long strip extending in the circumferential direction of the opening edge 21 with intervals at the four corners. Furthermore, the uppermost part 33 of the flange also serves as the primary sealing region 31. Moreover, as shown in Figures 19A and 19B, the portion of the lower part 34 of the flange that is continuously provided around the entire circumference of the opening edge 21 also serves as the secondary sealing region 32.

[0156] In this case, the upper surface of the primary sealing region 31 (e.g., the uppermost upper surface 330 of the flange) is located at the uppermost point of the upper surface 30 of the flange, and the upper surface of the secondary sealing region 32 (e.g., the portion of the lower upper surface 340 of the flange that is continuously provided around the circumference of the opening edge 21) is located below the upper surface of the primary sealing region 31 (e.g., the uppermost upper surface 330 of the flange). Furthermore, the flange portion 3 is configured such that when the cover member 5 and the primary sealing region 31 are sealed, a gap C is formed between the upper surface of the secondary sealing region 32 (e.g., the lower upper surface 340 of the flange) and the lower surface of the cover member 5, and the gap C is configured to become part of the flow path R.

[0157] In the packaging container 1 of the above embodiment, the primary sealing process is performed by line sealing, but it can also be performed by point sealing at least one point. For example, as shown in Figures 20A and 20B, a plurality of protrusions can be provided on the flange portion 3 as the uppermost part 33F of the sixth flange, and the uppermost part 33F of the sixth flange also serves as the primary sealing area 31. The shape of the uppermost part 33F of the flange is, for example, frustum-shaped. In addition, the uppermost part 33F of the flange can be provided at the four corners of the flange portion 3 and at the center of each side of the flange portion 3. In this way, when the plurality of primary sealing areas 31 are provided with gaps in the circumferential direction of the opening edge 21, after the primary sealing process is performed, the heating vapor S flows into the receiving portion 2 through the gaps between the primary sealing areas 31 in the circumferential direction, so that a sufficient amount of heating vapor S can flow into the receiving portion 2.

[0158] For example, as shown in Figures 21A and 21B, a plurality of recesses can be provided in the flange portion 3 as the lower flange portion 34. The lower flange portion 34 is arranged with gaps in the circumferential direction of the opening edge 21, and can be located, for example, at the four corners of the flange portion 3. In this case, the uppermost flange portion 33 is located on each side of the flange portion 3. In this configuration, the uppermost flange portion 33 also serves as a primary sealing area 31. Furthermore, in this configuration, after the primary sealing process, a gap C is generated between the lower surface of the cover member 5 and the upper surface 340 of the lower flange portion. This gap C is located at the four corners of the flange portion 3, so the heating steam S flows from the four corners of the flange portion 3 into the receiving portion 2.

[0159] In the packaging container 1 of the above embodiment, the shapes or sizes of the through holes 38 formed in the flange portion 3 are the same, but they may also be different. For example, as shown in Figures 22A and 22B, it is possible to provide a through hole 38A at one of the adjacent diagonal portions of the four corners of the flange portion 3, and to provide a through hole 38B of a different size from the through hole 38A at one of the other two corners of the four corners of the flange portion 3, other than the aforementioned adjacent diagonal portions. The diameter of the through hole 38A is larger than the diameter of the through hole 38B.

[0160] Furthermore, the uppermost part 33 of the flange may be a U-shaped or arc-shaped protrusion when viewed from above. For example, the uppermost part 33G of the seventh flange located outside the through hole 38A may be considered as a U-shaped protrusion. The uppermost part 33G of the seventh flange is provided along the outer part of the outer periphery of the through hole 38A. On the inner side of the through hole 38A, a plurality of (e.g., three) uppermost parts 33E of the fifth flange are provided along the opening edge 21. In this packaging container 1, the primary sealing area 31 is the outer periphery of the flange part 3.

[0161] Thus, on the inner side of the primary sealing area 31, since the uppermost part 33 of the flange is provided at both the outer and inner sides of the through hole 38A, the upper surface 330 of the uppermost part of the flange supports the cover member 5 on both the outer and inner sides of the through hole 38A, thereby maintaining a gap C between the through hole 38A and the cover member 5, thus preventing the through hole 38A from being closed.

[0162] In the above embodiment, a groove 39 is provided in the flange portion 3 as a recess, but a dot-shaped recess 39 may also be provided. For example, the recess 39 may be provided at the four corners of the flange portion 3. In addition, a through hole 38B may also be provided at the bottom of the recess 39.

[0163] Furthermore, after the secondary sealing process, the portion of the flange portion 3 containing the through hole 38 can be removed. For example, in the configuration described above where through holes 38 are provided at the four corners of the flange portion 3 (refer to Figures 22A and 22B), as shown in Figures 23A and 23B, a secondary sealing region 32 can be provided between the uppermost part 33E of the flange and the through hole 38. After the secondary sealing process, the flange portion 3 is cut off by the cutting line L between the through hole 38 and the secondary sealing region 32. In the configuration where the through hole 38 is located between the primary sealing region 31 and the secondary sealing region 32, water droplets tend to accumulate around the through hole 38 in the flange portion 3. However, by removing the portion of the flange portion 3 containing the through hole 38, water droplets can be prevented from affecting the packaging container 1.

[0164] In Figure 23, the cutting line L is provided by cutting off the four corners of the flange portion 3. However, it can also be provided by extending between the through hole 38 and the secondary sealing area 32 and continuously cutting off the entire circumference of the opening edge 21 in the circumferential direction. That is, the cutting line L can also be provided by cutting off the outer periphery of the through hole 38 including the flange portion 3.

[0165] The through area 36 in the above embodiment is circular when viewed from above, or it may be an elliptical or elongated shape. In this case, the through hole 38 may be slit-shaped. Furthermore, the through hole 38 in the above embodiment is formed by forming a crack 380 or punching through the through area 36 in which the cross-shaped groove 360 ​​is provided, but it may also be formed by other methods.

[0166] Furthermore, as shown in Figures 24A and 24B, it is possible to form through holes 38 by creating a U-shaped crack 380 in the flange portion 3 when viewed from above. In this configuration, the flange portion 3 has an uppermost eighth flange portion 33H, which is formed by deforming a portion of the flange portion 3 (e.g., the through region 36) upwards with the crack 380 as the boundary, and the upper surface is located at the uppermost of the upper surface 30 of the flange portion 3. In addition, a flow path R is formed between the cover member 5 and the flange portion 3 by the uppermost eighth flange portion 33H. Specifically, a U-shaped crack 380 is formed in the through region 36, and the inner part of the U-shaped crack 380 bends upwards more than other areas of the flange portion 3 to form through holes 38, and the uppermost eighth flange portion 33H is formed. In addition, a second flange uppermost part 33B may be provided near the through hole 38.

[0167] Furthermore, as shown in Figures 25A and 25B, it is possible to form a linear crack 380 on the flange portion 3 to thereby form each through hole 38. In this configuration, the through region 36 is raised above the region beyond the through region 36 of the flange portion 3, with a pair of straight lines 381 extending from both ends of the crack 380 as the boundary, and the through hole 38 is formed, and the uppermost part 33H of the eighth flange is formed.

[0168] Thus, in the configuration where the through-hole 38 is formed by deforming the through-hole 36 to a region above the through-hole 36 of the flange portion 3, when the heating steam S flows from below the flange portion 3 into the receiving portion 2, it is easy to keep the through-hole 36 in a raised state by the heating steam S, so it is easy to maintain the open state of the through-hole 38.

[0169] Furthermore, as shown in Figures 26A and 26B, in a configuration in which a through hole 38 is formed by placing the through region 36 above the region other than the through region 36 of the flange portion 3, and an uppermost portion 33H of the eighth flange is formed, an uppermost portion 33C of the third flange may be provided near the through hole 38.

[0170] Furthermore, as shown in Figures 27A and 27B, when deforming the through region 36 upwards, it is preferable to use an auxiliary tool to form a depression from the top at the junction 382 between the flange 3 and the through region 36, and to deform the through region 36 upwards starting from this depression. In this case, the junction 382 of the flange 3 becomes easier to bend, making it easier to maintain the state in which the through region 36 is raised.

[0171] According to this configuration, the uppermost part 33H of the eighth flange is formed by deforming a portion of the flange portion 3 with the crack 380 as the boundary, and the uppermost part 33H of the eighth flange forms a flow path R, so that the heating steam S can flow into the receiving portion 2 through this flow path R.

[0172] Furthermore, as shown in Figures 28A and 28B, in the case where the through hole 38 is formed to become the uppermost part 33H of the eighth flange, only the uppermost part 33H of the eighth flange can be provided as the uppermost part 33 of the flange portion 3. According to this configuration, even if no other uppermost part 33 of the flange is formed in the flange portion 3 except for the uppermost part 33H of the eighth flange, the through hole 38 can be formed simply by forming a crack 380 in the flange portion 3, thereby forming a flow path R for the heating steam S to flow through.

[0173] In the formation of the through-hole 38, the through-region 36 becomes the uppermost part 33H of the eighth flange. For example, the through-hole 38 can be formed by the following process. First, as shown in FIG29A, positioning is performed to form the crack 380 on the flange portion 3. As shown in FIG29B, the crack 380 is formed by using a cutting tool. Next, as shown in FIG29C, a tool for forming a recess is hammered into the junction 382 of the through-region 36. As shown in FIG29D, the through-region 36 is deformed upward by the impact, thereby forming the through-hole 38.

[0174] As shown in Figures 30A and 30B, the through region 36 is a convex portion protruding upwards, and the upper end of the convex portion can form the uppermost part 33H of the eighth flange. Furthermore, the through region 36 may, for example, have a curved surface that bulges upwards. In this through region 36, the upper end of the curved surface forms the uppermost part 33H of the eighth flange. The through region 36 of this embodiment is bowl-shaped. The entire upper surface of this through region 36 is a curved surface. Furthermore, the outer periphery of the through region 36 has an arc-shaped portion and a straight portion. On the outer periphery of the through region 36 of this embodiment, the arc-shaped portion is positioned further inward than the straight portion. Furthermore, in this configuration, by forming a crack 380 on a portion of the outer periphery of the through region 36 (e.g., the arc-shaped portion) and deforming the through region 36 upwards, as shown in Figure 30C, the through region 36 becomes an upwardly convex curved surface.

[0175] When the through region 36 is a convex portion protruding upwards, the entire upper surface of the convex portion can be an uncurved inclined surface, or only a portion of the upper surface of the convex portion can be a curved surface. For example, as shown in Figures 31A and 31B, the through region 36 can also be a convex portion of a curved surface that bulges upwards on the upper part of the upper surface, with the upper end of the curved surface forming the uppermost part 33H of the eighth flange. The lower part of the upper surface of the through region 36 is an inclined surface. The outer periphery of the through region 36 is a rectangle with rounded corners. Furthermore, in this configuration, by forming a crack 380 on a portion of the outer periphery of the through region 36 (for example, excluding the portion located on the outer side of the outer periphery, i.e., three sides and a pair of corners in the rectangular outer periphery) and deforming the through region 36 upwards, as shown in Figure 31C, the through region 36 becomes a curved surface that bulges upwards.

[0176] Thus, in the configuration where a portion of the flange portion 3 that deforms upward (e.g., the through region 36) is a curved surface that bulges upward, when the primary sealing region 31 and the cover member 5 are sealed, by forming a crack 380 in the flange portion 3, the convex curved surface that bends upward can stably support the cover member 5 without causing damage to the cover member 5.

[0177] In the above embodiment, in the packaging container 1 of Figures 24 to 31, the through area 36 is located above other areas of the flange portion 3, with the crack 380 as the boundary, but it can also be located below and form a through hole 38. In this case, the portion of the flange portion 3 other than the through area 36 can form the uppermost part 33 of the flange.

[0178] In the packaging container 1 of the above embodiment, a through hole 38 is provided at the corner of the flange portion 3. However, as shown in FIG32A, a through hole 38 may also be provided in the area other than the corner of the flange portion 3. Furthermore, the packaging container 1 of the above embodiment has one receiving portion 2. However, as shown in FIG32B to FIG32C, it may also have a plurality of receiving portions 2. In this case, the through hole 38 may be arranged between adjacent receiving portions 2 (enclosing the area of ​​the receiving portion 2).

[0179] In the packaging container 1 of the above embodiment, a through area 36 is provided in the flange portion 3. However, a through hole 38 may also be provided in the flange portion 3 in advance to replace the through area 36. In this case, the manufacturing method of the packaged food 6 does not include the through hole forming process, but becomes a method that includes a food containing process, a primary sealing process, a sterilization process, and a secondary sealing process.

[0180] In the above-described method for manufacturing packaged food, the food containing process, the through-hole forming process, the primary sealing process, the sterilization process, and the secondary sealing process are performed sequentially. However, the food containing process can also be performed after the through-hole forming process. Furthermore, the packaging container 1 can preferably be used as a packaging container 1 for packaged food 6, in which the through-hole 38 is provided in the through-area 36 of the flange portion 3 and the food F is contained in the containing portion 2, the cover member 5 is sealed to the primary sealing area 31 of the flange portion 3, and then the heating steam S is allowed to flow through the containing portion 2 via the flow path R to sterilize the food F, and then the cover member 5 is sealed to the secondary sealing area 32 of the flange portion 3.

[0181] The flange portion 3 of the above embodiment is provided around the entire circumference of the opening edge 21 in the circumferential direction, but it can also be provided in an interrupted state (with intervals) in this circumferential direction.

[0182] In the packaging container 1 of the above embodiment, the receiving part 2 and the flange part 3 are composed of a single component, but they can also be composed of different components. For example, the container body 4 can be formed with different components to form the receiving part 2 and the flange part 3, and the receiving part 2 or the flange part 3 can be connected by an adhesive, thereby connecting the receiving part 2 and the flange part 3.

[0183] Furthermore, in this invention, various contents can be contained as objects to be sterilized. The contents include, for example, articles from which contact with bacteria, dust, or other contaminants or oxygen is undesirable during storage or transportation, including food, cosmetics, pharmaceuticals, external medical supplies, medical devices, hygiene products, physiochemical products, and biological products. Food is preferred, and especially food that can maintain its appearance and quality during high-temperature, high-pressure steam sterilization (e.g., food that is solid when contained).

[0184] In addition, the sterilizing gas used in the present invention is heated steam in the above embodiment, but other gases with sterilizing effects such as ozone gas, ethylene oxide, formaldehyde, acetic acid, ethylene oxide, and chlorine dioxide may also be used depending on the contents.

[0185] From the above description, according to the present invention, a packaging container can be provided that is preferably used when sterilizing contents and can maintain the quality of sterilized contents over a long period of time.

[0186] The packaging container of the present invention is a sterilization treatment packaging container for exposing the contents contained therein to a sterilizing gas for sterilization, and then sealing the contents for circulation. The container body comprises: a receiving portion having an opening at the top for receiving the contents, and a flange extending outward from the opening edge of the receiving portion; the flange has: a primary sealing region that is primaryly sealed with a cover member covering the opening in a primary sealing process, and a secondary sealing region that is secondaryly sealed with the cover member in a secondary sealing process after the primary sealing process, and its upper surface is located on... The uppermost flange portion of the upper surface of the flange portion, the lower flange portion whose upper surface is located below the upper surface of the uppermost flange portion, and at least one through region located further inside than the aforementioned primary sealing region and having a through hole that passes through the aforementioned flange portion; and the aforementioned flange portion is configured such that after the aforementioned cover member and the aforementioned primary sealing region are sealed, a flow path is formed between the aforementioned cover member supported by the aforementioned upper flange portion and the aforementioned lower flange portion, allowing gas to flow between the outside and the aforementioned receiving portion, and after the aforementioned cover member and the aforementioned secondary sealing region are sealed, the aforementioned flow path is closed.

[0187] The packaging container configured in this way is suitable for use, for example, when the contents are contained in the receiving portion and a through hole is provided in the through area of ​​the flange portion, or when a through hole is provided in the through area of ​​the flange portion and the food is contained in the receiving portion, the lid member and the flange portion are sealed in a primary sealing area, and then sterilizing the contents by circulating sterilizing gas through the receiving portion via a flow path, and the lid member and the flange portion are sealed in a secondary sealing area.

[0188] In this packaging container, when a through hole is provided further inside the primary sealing area of ​​the flange portion, this through hole constitutes part of the flow path. Furthermore, when the primary sealing area and the cap member are sealed, a gap is created between the lower part of the flange portion and the cap member, and this gap constitutes part of the flow path. Therefore, when sterilizing the contents, sterilizing gas flows from below the flange portion through the flow path formed by the through hole and the gap into the receiving portion, thereby sterilizing the contents within the receiving portion.

[0189] Especially in packaging containers, since the upper surface of the uppermost part of the flange is located above the upper surface of the lower part of the flange, when sterilizing the contents, the uppermost part of the flange supports the cover member, so that the sterilizing gas can flow into the containment in a state in which the gap forming the flow path is reliably maintained by the uppermost part of the flange and is not closed.

[0190] Furthermore, in this packaging container, the lid member is located above the flow path, meaning the flow path is not exposed above the lid member. Therefore, even after sterilization by sterilizing gas, fallen bacteria are unlikely to enter the container through the flow path. In addition, since the flow path is closed by sealing the lid member with a secondary sealing area, the packaging container can completely seal the contents through the seal with the lid member.

[0191] Furthermore, in the aforementioned packaging container, the aforementioned through hole can also be formed by forming a crack in a portion of the aforementioned through area.

[0192] According to this configuration, when a through hole is formed in the through area, a portion of the flange portion will not break, and no fragments of the flange portion will be generated. Therefore, it is possible to prevent fragments of the flange portion from entering the receiving portion.

[0193] The aforementioned through area may also have a curved surface that bulges upward, and the upper end of the aforementioned curved surface may also form the uppermost part of the aforementioned flange.

[0194] According to this configuration, when the primary sealing area and the cover member are sealed, the aforementioned curved surface can support the cover member without causing damage.

[0195] In addition, in the aforementioned packaging container, the aforementioned through area may also be a recessed portion that is recessed downwards, and the aforementioned crack may also be formed in the recessed portion.

[0196] According to this configuration, when forming the through hole, the through area that is recessed from top to bottom is perforated, thereby making it easy to keep the perforated part of the through area in a state that is lower than other areas of the flange, thus preventing the through hole from being closed by that part.

[0197] Furthermore, in the aforementioned packaging container, the aforementioned flange portion may also be provided around the entire circumference of the opening edge of the aforementioned receiving portion, and the aforementioned through area may also be provided in multiples and arranged at opposite positions separated by the aforementioned receiving portion.

[0198] According to this configuration, since a through area is provided at a position opposite to the receiving portion, when a through hole is provided at this position, gas can be allowed to flow through the through hole from both sides of the receiving portion, thus suppressing uneven heating of the food.

[0199] Another packaging container of the present invention is a packaging container for exposing the contents contained therein to a sterilizing gas for sterilization, and then sealing the contents for circulation. The packaging container has a container body, which includes: a receiving portion having an opening at the top and containing the contents, and a flange portion extending outward from the opening edge of the receiving portion; the flange portion has: a primary sealing area that is sealed once with a cover member covering the opening in a primary sealing process, and a secondary sealing area that is sealed twice with the cover member in a secondary sealing process after the primary sealing; and the flange portion is configured such that after the cover member and the primary sealing area are sealed, a flow path is formed between the flange portion and the cover member, allowing gas to flow between the outside and the receiving portion, and after the cover member and the secondary sealing area are sealed, the flow path is closed.

[0200] The packaging container with this configuration is suitable for use as a container that, after the contents are contained in the containment portion and the primary sealing area of ​​the lid member and the flange portion is sealed, and then sterilizing the contents by allowing sterilizing gas to circulate through the containment portion via a flow path, seals the secondary sealing area of ​​the lid member and the flange portion.

[0201] In this packaging container, when the primary sealing area and the cap member are sealed, when the contents are sterilized, sterilizing gas is allowed to flow from below the flange through the flow path into the containment, thereby sterilizing the contents in the containment.

[0202] Furthermore, in this packaging container, the lid member is located above the flow path, meaning the flow path is not exposed above the lid member. Therefore, even after sterilization by sterilizing gas, fallen bacteria are unlikely to enter the container through the flow path. In addition, since the flow path is closed by sealing the lid member with a secondary sealing area, the packaging container can completely seal the contents through the seal with the lid member.

[0203] In addition, at least one through hole through the flange portion of the aforementioned packaging container may be provided at a location further inside than the aforementioned primary sealing area, and the aforementioned through hole may also be configured to become part of the aforementioned flow path.

[0204] According to this configuration, after a sealing process, sterilizing gas flows from below the flange through the aforementioned through hole, which becomes part of the flow path, into the container, thereby sterilizing the food in the container.

[0205] Furthermore, in the aforementioned packaging container, the aforementioned through hole can also be formed by forming a crack on a portion of the aforementioned flange.

[0206] According to this configuration, when the through hole is provided, a portion of the flange portion will not break, and no fragments of the flange portion will be generated. Therefore, it is possible to prevent fragments of the flange portion from entering the receiving portion.

[0207] In addition, in the aforementioned packaging container, the aforementioned flange portion may also have: an uppermost flange portion formed by deforming a portion of the aforementioned flange portion upward with the aforementioned crack as the boundary, and the aforementioned flow path may also be formed between the aforementioned cover member supported by the uppermost flange portion and the aforementioned flange portion.

[0208] According to this configuration, by forming a crack on the flange portion, a through hole and the uppermost part of the flange can be formed simultaneously.

[0209] Furthermore, in the aforementioned packaging container, a portion of the aforementioned flange portion that deforms upwards may also have a curved surface that bulges upwards.

[0210] According to this configuration, when the primary sealing area and the cover member are sealed, the aforementioned curved surface can support the cover member without causing damage to it.

[0211] In addition, in the aforementioned packaging container, the aforementioned flange portion may also have: its upper surface is located at the uppermost flange portion of the upper surface of the flange portion, and the aforementioned flow path may also be formed between the aforementioned cover member supported by the uppermost flange portion and the aforementioned flange portion.

[0212] According to this configuration, from the time of the first sealing process to the time of the second sealing process, that is, when the contents are sterilized, since the cover member is supported by the uppermost part of the aforementioned flange, the sterilizing gas can be more reliably circulated in the containment through the formed flow path.

[0213] Furthermore, in the aforementioned packaging container, the aforementioned flange portion may also be provided around the entire circumference of the opening edge of the aforementioned receiving portion, and the aforementioned through area may also be provided in multiples and arranged at opposite positions separated by the aforementioned receiving portion.

[0214] According to this configuration, by allowing gas to flow through the through holes disposed between the two sides of the container, uneven heating of the food can be suppressed.

[0215] In addition, in the aforementioned packaging container, the upper surface of the aforementioned primary sealing area may be located at the uppermost of the upper surface of the aforementioned flange portion, and the upper surface of the aforementioned secondary sealing area may be located below the upper surface of the aforementioned primary sealing area. After the aforementioned cover member and the aforementioned primary sealing area are sealed, the aforementioned flange portion forms a gap between the upper surface of the aforementioned secondary sealing area and the lower surface of the aforementioned cover member. The aforementioned gap may also be formed in a way that becomes part of the aforementioned flow path.

[0216] According to this configuration, from the time of the first sealing process to the time of the second sealing process, that is, when the contents are sterilized, since the upper surface of the first sealing area is located above the upper surface of the aforementioned second sealing area, and the gap mentioned above is maintained as part of the flow path by the first sealing area, the first sealing area reliably maintains the state in which the gap is not closed, so that gas can flow into the containment through the through hole.

[0217] In addition, in the aforementioned packaging container, the aforementioned receiving portion may also include a base plate containing the contents, and the upper surface of the aforementioned base plate may also have an uneven shape.

[0218] According to this configuration, when the contents are placed in the receiving section, a gap is created below the contents. Therefore, when the sterilizing gas flows through the receiving section, the sterilizing gas flows not only above the contents but also below. Thus, the contents can be sterilized from both above and below by the sterilizing gas.

[0219] The packaging container of the present invention may also have a lid member, and the aforementioned container body and the aforementioned lid member may also be composed of a multi-layer structure containing at least one gas barrier layer.

[0220] According to this configuration, by providing a gas barrier layer to the container body or lid component, the sterilization state inside the packaging container can be maintained for a longer period of time.

[0220] [Effects of the Invention]

[0221] From the above description, according to the present invention, a packaging container that is preferably used when sterilizing contents and that can maintain the quality of sterilized contents over a long period of time can be provided.

Claims

1. A packaging container for sterilization treatment, used to expose the contents contained therein to a sterilizing gas for sterilization, and then to seal the contents for distribution. The aforementioned packaging container has a container body, which includes: a receiving portion having an opening at the top for receiving contents, and a flange portion extending outward from the opening edge of the aforementioned receiving portion; The aforementioned flange portion has: The primary sealing area is the area that is sealed once during a primary sealing process with the cover component that covers the aforementioned opening; The secondary sealing area is where the aforementioned cover component is sealed a second time after the primary sealing process, thereby completely sealing the contents. The uppermost part of the flange has its upper surface located at the topmost point of the upper surface of the flange portion; The lower part of the flange, the upper surface of which is located below the uppermost upper surface of the flange; and At least one through area is located inside the aforementioned primary sealing area and is provided with a through hole that penetrates the aforementioned flange portion. Furthermore, the aforementioned flange portion is configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a flow path is formed between the aforementioned cover member and the aforementioned lower part of the aforementioned flange, which is supported by the uppermost part of the aforementioned flange, allowing gas to flow between the outside and the aforementioned receiving portion. After the aforementioned cover member and the aforementioned secondary sealing area are sealed, the aforementioned flow path is closed.

2. The packaging container as described in claim 1, wherein, The aforementioned through hole is formed by creating a crack in a portion of the aforementioned through region.

3. The packaging container as described in claim 2, wherein, The aforementioned through region has a curved surface that bulges upwards. The upper end of the aforementioned curved surface constitutes the uppermost part of the aforementioned flange.

4. The packaging container as described in claim 2, wherein, The aforementioned through area is a concave portion that extends downwards, and the aforementioned crack is formed within this concave portion.

5. The packaging container as described in any one of claims 1 to 4, wherein, The aforementioned flange portion is provided around the entire circumference of the opening edge of the aforementioned receiving portion. The aforementioned through areas are provided in multiples and are arranged in opposite positions separated by the aforementioned receiving parts.

6. A packaging container for exposing contents contained therein to a sterilizing gas for sterilization, and then sealing the contents for distribution. The aforementioned packaging container has a container body, which includes: a receiving portion having an opening at the top for receiving contents, and a flange portion extending outward from the opening edge of the aforementioned receiving portion; The aforementioned flange portion has: The primary sealing area is the area that is sealed once during a primary sealing process with the cover member covering the aforementioned opening; and The secondary sealing area is the area where the aforementioned cover component is sealed a second time after the primary sealing process. Furthermore, the aforementioned flange portion is configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a flow path is formed between it and the aforementioned cover member, allowing gas to flow between the outside and the aforementioned receiving portion. After the aforementioned cover member and the aforementioned secondary sealing area are sealed, the aforementioned flow path is closed.

7. The packaging container as described in claim 6, wherein, In the aforementioned flange portion, at least one through hole is provided at a location further inside than the aforementioned primary sealing area, penetrating the aforementioned flange portion. The aforementioned through holes are configured to be part of the aforementioned flow path.

8. The packaging container as described in claim 7, wherein, The aforementioned through hole is formed by creating a crack in a portion of the aforementioned flange.

9. The packaging container as described in claim 8, wherein, The aforementioned flange portion has: an uppermost flange portion formed by deforming a portion of the aforementioned flange portion upwards with the aforementioned crack as the boundary. The aforementioned flow path is formed between the aforementioned cover member supported by the uppermost part of the flange and the aforementioned flange portion.

10. The packaging container as described in claim 9, wherein, The portion of the aforementioned flange that deforms upwards has a curved surface that bulges upwards.

11. The packaging container as described in any one of claims 6 to 8, wherein, The aforementioned flange portion has: the uppermost part of the flange portion, the upper surface of which is located at the uppermost point of the upper surface of the flange portion. The aforementioned flow path is formed between the cover member and the aforementioned flange portion, which are supported by the uppermost part of the flange.

12. The packaging container as described in any one of claims 7 to 10, wherein, The aforementioned flange portion is provided around the entire circumference of the opening edge of the aforementioned receiving portion. The aforementioned through holes are provided in multiples and are arranged in opposite positions separated by the aforementioned receiving portion.

13. The packaging container as described in claim 7, wherein, The upper surface of the aforementioned primary sealing area is located at the uppermost point of the upper surface of the aforementioned flange portion. The upper surface of the aforementioned secondary sealing area is located below the upper surface of the aforementioned primary sealing area. The aforementioned flange is configured such that, after the aforementioned cover member and the aforementioned primary sealing area are sealed, a gap is formed between the upper surface of the aforementioned secondary sealing area and the lower surface of the aforementioned cover member. The aforementioned gap is formed in such a way that it becomes part of the aforementioned flow path.

14. The packaging container as described in any one of claims 1 to 10, wherein, The aforementioned receiving section includes a base plate containing the contents. The upper surface of the aforementioned base plate has an uneven shape.

15. The packaging container as described in any one of claims 1 to 10 further comprises a lid member. The aforementioned container body and the aforementioned cover component are composed of a multi-layer structure containing at least one gas barrier layer.

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