Packaging containers for sterilization

Abstract

The present invention is a packaging container with a container body, wherein the container body includes a receiving portion and a flange portion, the flange portion having: a primary sealing area that is sealed once with a cover member; a secondary sealing area that is sealed twice with the cover member; a flange uppermost portion whose upper surface is located at the top of the upper surface of the flange portion; a flange lower portion whose upper surface is located lower than the upper surface of the flange uppermost portion; and a through-area that is located further inside than the primary sealing area and is provided with a through hole that passes through the flange portion, and is constructed as follows: after the primary sealing area is sealed, a gap is formed between the upper surface of the flange lower portion and the cover member, and a flow path is formed between the flange lower portion and the cover member for gas to flow between the outside and the receiving portion, and after the secondary sealing area is sealed, the flow path is closed.

Description

[0001] Cross-references of related applications

[0002] This application claims the priority of Japanese Patent Application No. 2019-223878, and incorporates the description of this application specification by reference. Technical Field

[0003] The present invention relates to a packaging container for sterilization treatment, for example, to a packaging container that can be preferably used when packaging food such as side dishes as contents and performing sterilization treatment. Background Art

[0004] Among packaged foods, there are packaged foods that are cooked and processed in food factories, etc., placed in containers with openings, and circulated in a state where the containers are top-sealed or covered. However, since packaged foods using top seals or covers are not completely sealed, external air may intrude into the containers. Therefore, the shelf life of such packaged foods is extremely short, approximately only 1 to 2 days, and there is a problem of extremely high waste loss rate (poor product yield).

[0005] Recently, as such packaged food, there is a packaged food circulating in the market, that is, the container and the lid are heat-sealed to completely seal the container, thereby extending the shelf life. There is also a packaged food that has a shelf life of more than two weeks by refrigerated storage.

[0006] However, even if the container can be sealed by heat sealing or the like to prevent bacteria from invading from the outside, the interior of the formed container is not completely sterile. Therefore, it is considered very likely that bacteria in the container will multiply due to environmental changes during the circulation process. Therefore, in order to further extend the shelf life, the working environment in the food factory needs to be as close to a sterile state as possible, so strict management of cleanliness is required. In the past, a method has been proposed: after the food is placed in the container and sterilized by heating, the container body is sealed in a clean room (sterile room) by a cover component (patent document 1). For example, the cleanliness of the working environment for handling cooked food is also managed to a high level of 10000 or 1000 of the NASA standard clean room. However, when such a clean room is introduced, there is a problem of extremely high cost in the installation and maintenance of air-conditioning equipment.

[0007] Furthermore, in addition to food, there are various objects that need to be sterilized before being distributed in the market as products, and these objects are required to be sterilized efficiently.

[0008] Prior art literature

[0009] Patent document 1: Japanese Patent Application Laid-Open No. 9-9937. Summary of the invention

[0010] Problems to be solved by the invention

[0011] The present invention aims to provide a packaging container that is preferably used when sterilizing contents, for example, a packaging container that is preferably used for sterilizing food as an example of the contents and that can extend the shelf life of the food.

[0012] Means for solving problems

[0013] The packaging container of the present invention is a packaging container for sterilization treatment, which is used to expose the contents contained inside to a sterilization gas for sterilization, and then seal the contents to allow them to circulate. The packaging container has a container body, which includes: a receiving portion with an opening at the top and receiving the contents, and a flange portion extending outward from the opening edge of the receiving portion, wherein the flange portion has: a primary sealing area, which is sealed with a cover member covering the opening in the primary sealing process; a secondary sealing area, which is sealed with the cover member in the secondary sealing process after the primary sealing process; and a flange portion extending outward from the opening edge of the receiving portion. The flange portion comprises an uppermost portion, an upper surface of which is located at the uppermost portion of the upper surface of the flange portion; a flange lower portion, an upper surface of which is located lower than the upper surface of the uppermost portion of the flange; and at least one through-region, which is located on the inner side than the primary sealing region and is provided with a through hole that penetrates the flange portion, and the flange portion is configured so that, when the cover member and the primary sealing region are sealed, a flow path for gas to flow between the outside and the inside of the housing portion is formed between the cover member supported by the uppermost portion of the flange and the flange lower portion, and the flow path is closed after the cover member and the secondary sealing region are sealed.

[0014] Furthermore, in the packaging container, the through hole may be formed by forming a slit in a part of the through region.

[0015] The penetration region may have a curved surface that bulges upward, and an upper end of the curved surface may constitute an uppermost portion of the flange.

[0016] Furthermore, in the packaging container, the penetration region may be a recessed portion recessed downward, and the crack may be formed in the recessed portion.

[0017] Furthermore, in the packaging container, the flange portion may be provided over the entire circumference of the opening edge of the housing portion, a plurality of the through regions may be provided, and the through regions may be arranged at opposing positions across the housing portion.

[0018] Another packaging container of the present invention is used for exposing the contents contained inside to a sterilizing gas for sterilization, and then sealing the contents to allow them to circulate. The packaging container has a container body, which includes: a receiving portion with an opening at the top and which receives 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 secondarily with the cover member in a secondary sealing process after the primary sealing process, and the flange portion is constructed as follows: when the cover member and the primary sealing area are sealed, a flow path is formed between the flange portion and the cover member for allowing gas to flow between the outside and the inside of the receiving portion, and after the cover member and the secondary sealing area are sealed, the flow path is closed.

[0019] Furthermore, the flange portion of the packaging container may be provided with at least one through hole penetrating the flange portion on the inner side of the primary sealing region, and the through hole may be configured to constitute a part of the flow path.

[0020] Furthermore, in the packaging container, the through hole may be formed by forming a slit in a part of the flange portion.

[0021] Furthermore, in the packaging container, the flange portion may include a flange uppermost portion formed by deforming a portion of the flange portion upward with the crack as a boundary, and the flow path may be formed between the lid member supported by the flange uppermost portion and the flange portion.

[0022] Furthermore, in the packaging container, a part of the flange portion deformed upward may have a curved surface bulging upward.

[0023] Furthermore, in the packaging container, the flange portion may include a flange uppermost portion, an upper surface of which is located at the uppermost of the upper surfaces of the flange portion, and the flow path is formed between the lid member supported by the flange uppermost portion and the flange portion.

[0024] Furthermore, in the packaging container, the flange portion may be provided on the entire periphery of the opening edge of the housing portion, a plurality of through holes may be provided, and the through holes may be arranged at positions facing each other across the housing portion.

[0025] In addition, in the packaging container, it can also be configured that the upper surface of the primary sealing area is located at the top of the upper surface of the flange portion, and the upper surface of the secondary sealing area is located below the upper surface of the primary sealing area, and the flange portion is configured so that after the cover part and the primary sealing area are sealed, a gap is formed between the upper surface of the secondary sealing area and the lower surface of the cover part, and the gap is configured in a manner to become a part of the flow path.

[0026] In the packaging container, the storage portion may include a bottom plate on which the contents are placed, and the top surface of the bottom plate may have a concavo-convex shape.

[0027] The packaging container of the present invention may further include a cover member, wherein the container body and the cover member are composed of a multilayer structure including at least one gas barrier layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A It is a schematic diagram of an embodiment of a packaging container of the present invention, and is a top view of the packaging container.

[0029] Figure 1B It is a schematic diagram of an embodiment of the packaging container and a side view of the packaging container.

[0030] Figure 2 for Figure 1A Cross-sectional view at position II-II.

[0031] Figure 3 The figures show the respective steps in the method for manufacturing the packaging container.

[0032] Figure 4A It is a schematic diagram of the packaging container after the through-hole forming process and the food accommodating process, and is a top view of the packaging container.

[0033] Figure 4B It is a schematic diagram of the packaging container after the through-hole forming process and the food storage process, and is a side view of the packaging container.

[0034] Figure 5 for Figure 4A Cross-sectional view at position VV of FIG.

[0035] Fig. 6A 1 is a schematic diagram of the packaging container after a primary sealing process, and 2 is a top view of the packaging container.

[0036] Figure 6B It is a schematic diagram of the packaging container after a primary sealing process, and it is a side view of the packaging container.

[0037] Figure 7 for Fig. 6A Cross-sectional view at position VII-VII.

[0038] Fig. 8A 1 is a schematic diagram of the packaging container after the secondary sealing process, and 2 is a top view of the packaging container.

[0039] Figure 8B It is a schematic diagram of the packaging container after the secondary sealing process, and it is a side view of the packaging container.

[0040] Fig. 9 for Fig. 8A Cross-sectional view at position IX-IX.

[0041] Fig. 10A Schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the packaging container.

[0042] Fig. 10B is a schematic diagram of another embodiment of the packaging container of the present invention, Fig. 10A Cross-sectional view at position XX.

[0043] Fig.11A 1 is a schematic diagram of the packaging container after the through-hole forming step, and 2 is a top view of the packaging container.

[0044] Fig. 11B is a schematic diagram of the packaging container after the through hole forming process, Fig.11A Cross-sectional view at the XI-XI position.

[0045] Fig. 12A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0046] Fig. 12B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig. 12A Cross-sectional view at position XII-XII.

[0047] Fig.13A This is a schematic diagram of another embodiment of the packaging container after the secondary sealing process, and is a top view of the packaging container.

[0048] Fig. 13B is a schematic diagram of another embodiment of the packaging container after the secondary sealing process, Fig.13A Cross-sectional view at position XIII-XIII.

[0049] Fig.14A for Fig. 12AThe schematic diagram of the packaging container after the secondary sealing process is shown as a top view of the packaging container.

[0050] Fig. 14B for Fig. 12A The schematic diagram of the packaging container after the secondary sealing process is shown in FIG. Fig.14A Cross-sectional view at position XIV-XIV.

[0051] Fig.15A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0052] Fig. 15B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig.15A Cross-sectional view at position XV-XV of .

[0053] Fig.16A This is a schematic diagram of another embodiment of the packaging container after the secondary sealing process, and is a top view of the packaging container.

[0054] Fig. 16B is a schematic diagram of another embodiment of the packaging container after the secondary sealing process, Fig.16A Cross-sectional view at position XVI-XVI.

[0055] Fig.17A It is a schematic diagram of another embodiment of the packaging container of the present invention, and is a plan view of the packaging container before the through-hole forming step.

[0056] Fig. 17B It is a schematic diagram of another embodiment of the packaging container of the present invention, and is a plan view of the packaging container after the through-hole forming step.

[0057] Fig.18A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0058] Fig.18B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig.18A Cross-sectional view at position XVIII-XVIII.

[0059] Fig.19A 1 is a schematic diagram of the packaging container after the secondary sealing process, and 2 is a top view of the packaging container.

[0060] Fig.19B is a schematic diagram of the packaging container after the secondary sealing process, Fig.19A Cross-sectional view at position XIX-XIX.

[0061] Fig. 20A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0062] Fig. 20B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig. 20A Cross-sectional view at position XX-XX.

[0063] Fig.21A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0064] Fig.21B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig.21A Cross-sectional view at position XXI-XXI.

[0065] Fig.22A This is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing step, and is a top view of the packaging container.

[0066] Fig. 22B Schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process. Fig.22A Cross-sectional view at position XXII-XXII.

[0067] Fig.23A 1 is a schematic diagram of the packaging container after the secondary sealing process, and 2 is a top view of the packaging container.

[0068] Fig. 23B is a schematic diagram of the packaging container after the secondary sealing process, Fig.23A Cross-sectional view at position XXIII-XXIII.

[0069] Fig.24A This is a schematic diagram of another embodiment of the packaging container of the present invention after the through-hole forming step, and is a top view of the packaging container.

[0070] Fig. 24B Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step. Fig.24A A cross-sectional view at position XXIV-XXIV.

[0071] Fig.25A This is a schematic diagram of another embodiment of the packaging container of the present invention after the through-hole forming step, and is a top view of the packaging container.

[0072] Fig.25BSchematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step. Fig.25A Cross-sectional view at position XXV-XXV.

[0073] Fig.26A Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step, showing Fig.24A A top view of a modified example of .

[0074] Fig.26B Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step, showing Fig.25A A partial top view of a modified example of .

[0075] Fig.27A Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step, showing Fig.24A A cross-sectional view of a modified example of .

[0076] Fig.27B Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step, showing Fig.25A A cross-sectional view of a modified example of .

[0077] Fig.28A This is a schematic diagram of another embodiment of the packaging container of the present invention after the through-hole forming step, and is a top view of the packaging container.

[0078] Fig.28B Schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming step. Fig.28A Cross-sectional view at position XXVIII-XXVIII.

[0079] Fig.29A This is a cross-sectional view for explaining a through-hole forming step in the packaging container, and shows a state before the through-hole forming step.

[0080] Fig.29B This is a cross-sectional view for explaining the step of forming a through hole in the packaging container, showing the step of forming a slit in the flange portion.

[0081] Fig.29C This is a cross-sectional view for explaining the step of forming the through hole in the packaging container, showing the step of forming the uppermost portion of the flange.

[0082] Fig.29D This is a cross-sectional view for explaining the step of forming the through hole in the packaging container, showing a state after the uppermost portion of the flange is formed.

[0083] Fig. 30AIt is a schematic diagram of another embodiment of the packaging container of the present invention, and is a plan view of the packaging container before the through-hole forming step.

[0084] Fig. 30B is a schematic diagram of another embodiment of the packaging container of the present invention, Fig. 30A sectional view of .

[0085] Fig. 30C It is a schematic diagram of another embodiment of the packaging container of the present invention, and is a cross-sectional view after the through-hole forming step.

[0086] Fig.31A It is a schematic diagram of another embodiment of the packaging container of the present invention, and is a plan view of the packaging container before the through-hole forming step.

[0087] Fig.31B is a schematic diagram of another embodiment of the packaging container of the present invention, Fig.31A sectional view of .

[0088] Fig.31C It is a schematic diagram of another embodiment of the packaging container of the present invention, and is a cross-sectional view after the through-hole forming step.

[0089] Fig.32A It is a schematic diagram after the through-hole forming step of another embodiment of the packaging container of the present invention, and is a schematic diagram showing a first modification.

[0090] Fig.32B It is a schematic diagram after the through-hole forming step of another embodiment of the packaging container of the present invention, and is a schematic diagram showing a second modification.

[0091] Fig.32C It is a schematic diagram after the through-hole forming step of another embodiment of the packaging container of the present invention, and is a schematic diagram showing a third modified example. DETAILED DESCRIPTION

[0092] Referring to Figures 1 to Fig. 9 FIG1 and FIG2 illustrate one embodiment of the present invention. Figure 2 1 is a diagram showing an embodiment of a packaging container of the present invention. Figure 3 FIG. 4 to FIG. 5 are diagrams for explaining an embodiment of a method for manufacturing a packaged food of the present invention. Fig. 9 The following is a diagram showing the steps of the manufacturing method in order.

[0093] First, the structure of a packaging container according to an embodiment of the present invention is described. The packaging container of this embodiment is a packaging container for sterilization treatment as described below: it is used to sterilize food as an example of the contents contained inside by exposing it to heated steam as an example of the sterilizing gas, and then to seal the contents (e.g., food) and distribute it as packaged food. As shown in Figures 1 and Figure 2 As shown, the packaging container 1 includes a container body 4 including a housing portion 2 having an opening 20 at the upper side and a flange portion 3 extending outward from an opening edge 21 of the housing portion 2 .

[0094] Below, the up-down direction in the packaging container 1 is the same as in FIG. Figure 2 Figure 4 to Fig. 9 In addition, the inner side and the outer side of the flange portion 3 are consistent with the side close to the opening edge 21 and the side away from the opening edge 21 of the flange portion 3.

[0095] like Figure 1A and Figure 1B As shown, the container body 4 is a container that can be closed by a cover member. The container body 4 of the present embodiment is in the shape of a tray, but may also be in any shape such as a cup shape, a bottle shape, etc. In addition, the material of the container body 4 is a synthetic resin. The thickness of the container body 4 is not uniform depending on the location, but may be the same at any location. In the container body 4 of the present embodiment, the thickness of the flange portion 3 is greater than the thickness of the receiving portion 2. In the container body 4 of the present embodiment, the receiving portion 2 and the flange portion 3 are composed of one component. Specifically, the container body 4 is formed by molding a sheet of material.

[0096] In addition, the cover member of the present embodiment has flexibility. The cover member is made of, for example, a film material made of synthetic resin. Specifically, the film material constituting the cover member is a biaxially stretched plastic film material.

[0097] The storage part 2 is a part for storing food. The storage part 2 of this embodiment includes a bottom plate 22 located below. In addition, the storage part 2 includes a side wall 23 extending upward from the outer peripheral edge of the bottom plate 22.

[0098] The bottom plate 22 is, for example, a rectangular plate with rounded corners. The bottom plate 22 has an upper bottom surface 220 that contacts food and a lower bottom surface 221 that is placed on a placement surface when the container body 4 is placed on the placement surface.

[0099] The bottom plate upper surface 220 has a concavoconvex shape. Specifically, a plurality of bottom plate protrusions 222 are provided in the central portion other than the four corners of the bottom plate upper surface 220 to protrude upward from the bottom plate upper surface 220. In addition, the four corners of the bottom plate upper surface 220 are composed of bottom plate inclined surfaces 223, where the closer to the vertex of each corner, the higher the position.

[0100] The bottom plate protrusions 222 are arranged at substantially equal or unequal intervals. A steam flow portion for steam flow is formed between the pair of bottom plate protrusions 222, 222, and the bottom plate protrusions 222 support the contents accommodated in the container body 4 in a point contact or line contact manner, for example. In addition, the bottom plate protrusions 222 are designed to reduce the contact area between the bottom plate protrusions 222 and the contents as much as possible.

[0101] exist Figure 1A In the illustrated embodiment, a plurality of steam flow portions formed between the bottom plate protrusions 222, 222 are arranged at substantially equal intervals. According to this structure, when the contents (e.g., food) contained in the container body 4 are sterilized by steam, the steam is passed through the steam flow path formed at the bottom, so that the steam flows in not only from the upper surface and the side surface of the contents but also from the lower surface of the contents, thereby making it possible to sterilize the contents more uniformly and effectively by steam.

[0102] The height of the bottom plate protrusion 222 does not need to be particularly limited, and is based on the innermost surface of the bottom of the container (i.e., the lowest height of the inner surface of the container body 4), for example, 2 mm or more, 3 mm or more, or 4 mm or more. In addition, the height of the bottom plate protrusion 222 does not need to be particularly limited, and is based on the innermost surface of the bottom of the container, for example, 15 mm or less, 13 mm or less, or 10 mm or less. By making the height of the bottom plate protrusion 222 within this range, steam can more easily flow into the steam flow path, and steam sterilization on the lower surface side of the content can be more effectively performed.

[0103] The height of the bottom plate protrusion 222 is preferably not less than 10% and not more than 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 structure, 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 content can be performed more effectively.

[0104] The bottom plate inclined surface 223 is provided to eliminate the corner of the receiving portion 2. For example, when taking out food received in the receiving portion 2, the bottom plate inclined surface 223 prevents the food from being retained near the corner of the bottom plate 22, and the food can be easily taken out of the receiving portion 2. In addition, the bottom plate inclined surface 223 is arranged in a state of being spaced apart from the bottom plate protrusion 222.

[0105] The side wall 23 is configured such that, for example, the portion located upward becomes wider in a plan view. The upper end edge of the side wall 23 constitutes the opening edge 21 of the housing portion 2.

[0106] The flange portion 3 is a portion for sealing with the cover member. The flange portion 3 is, for example, provided around the entire circumference of the opening edge 21. The flange portion 3 of the present embodiment is generally plate-shaped and is configured in an annular shape so as to surround the accommodating portion 2 when viewed from above. Specifically, the flange portion 3 is annular with four corners when viewed from above.

[0107] In addition, if Figure 2 As shown, the flange portion 3 has a flange upper surface 30 facing upward and a flange lower surface 35 facing downward. In addition, the flange portion 3 has: a primary sealing area 31 sealed with a cover member covering the opening 20 in a primary sealing process; and a secondary sealing area 32 sealed with the cover member in a secondary sealing process. In addition, the flange portion 3 has a flange uppermost portion 33 and a flange lower portion 34. The flange uppermost portion 33 has a flange uppermost portion upper surface 330 located at the top of the flange upper surface 30. The flange lower portion 34 has a flange lower portion upper surface 340 located below the flange uppermost portion upper surface 330.

[0108] The flange portion 3 of the present embodiment has a through region 36 (see Figure 1A ). In the present embodiment, the through hole, that is, the through area 36 is located further inside than the primary sealing area 31. The through hole provided in the through area 36 passes through between the flange lower surface 35 and the flange upper surface 30. In addition, in the flange portion 3 of the present embodiment, a plurality of through areas 36 are provided.

[0109] The number of through-regions 36 provided in the flange portion 3 may be one, but it is preferably a plurality of through-regions 36 because it is preferred that both through-holes for allowing gas to flow into the flange portion 3 and through-holes for allowing gas to flow out of the flange portion 3 are provided in the flange portion 3. Specifically, the flange portion 3 is provided with the same number of through-regions 36 as the number of corners of the flange portion 3 (for example, four in this embodiment).

[0110] The primary sealing region 31 is a part of the flange 3 and is a region where the lid member and the flange 3 are temporarily sealed in a primary sealing process. The primary sealing process is a process performed after the food is accommodated in the accommodating portion 2 and before the accommodated food is sterilized.

[0111] The primary seal area 31 of the present embodiment is located at the outer peripheral portion of the flange portion 3. In addition, the primary seal area 31 is continuous in the circumferential direction of the opening edge 21. Specifically, the primary seal area 31 is located inside the outer peripheral edge of the outer peripheral portion of the flange portion 3 and extends continuously in the circumferential direction. More specifically, the primary seal area 31 is located inside the outer peripheral edge of the outer peripheral portion of the flange portion 3 and extends continuously in the entire circumferential range of the opening edge 21.

[0112] The secondary sealing area 32 is an area where the cover member and the flange portion 3 are sealed in the secondary sealing process as a sealing process. The secondary sealing process is performed after the food contained in the containing portion 2 is sterilized. The secondary sealing area 32 is at least a part of the flange portion 3. In addition, the secondary sealing area 32 may also include an area overlapping (the same as) the primary sealing area 31. The secondary sealing area 32 of the present embodiment is the entire area of ​​the flange portion 3.

[0113] 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 flange uppermost portion 33 or the flange lower portion 34 (refer to Figure 1B ).

[0114] The flange uppermost portion 33 is a portion whose upper surface is relatively located above. The flange uppermost portion upper surface 330 of the present embodiment is located, for example, about 1 mm or more above the flange lower portion upper surface 340. After the primary sealing process and before the secondary sealing process, the flange uppermost portion 33 can support the cover member at a position higher than the flange lower portion upper surface 340.

[0115] Specifically, the flange uppermost portion 33 is a convex portion formed by partially pressing the flange portion 3 upward from below. As a result, the flange uppermost portion upper surface 330 protrudes upward. The flange uppermost portion 33 of the present embodiment is hollow, but may also be solid.

[0116] In the flange portion 3 of this embodiment, a flange uppermost portion 33 having a different shape is provided. Figure 1A As shown, the flange uppermost portion 33 includes: a first flange uppermost portion 33A having an elliptical shape when viewed from above; and a second flange uppermost portion 33B having a circular shape when viewed from above. The first flange uppermost portion 33A and the second flange uppermost portion 33B are both convex portions having a curved surface on the flange uppermost portion upper surface 330. In addition, the first flange uppermost portion 33A and the second flange uppermost portion 33B are both convex portions having a height (dimension in the vertical direction) smaller than the outer diameter when viewed from above.

[0117] In addition, the flange uppermost portion 33 of the present embodiment is provided near the through-region 36. For example, at least one of the flange uppermost portions 33 is provided inside the through-region 36. All of the flange uppermost portions 33 of the present embodiment are provided inside the through-region 36. Specifically, a plurality of flange uppermost portions 33 (for example, a pair of each) are provided inside each through-region 36. The flange uppermost portions 33 may be provided one at a time inside the through-region 36 in a manner corresponding to each through-region 36, but after a sealing process is performed once, it is preferred that a plurality of flange uppermost portions 33 be provided to support the cover member.

[0118] The flange lower portion 34 is a portion whose upper surface is relatively located downward. The flange lower portion 34 of the present embodiment is a portion of the flange portion 3 other than the flange uppermost portion 33 .

[0119] The through-region 36 is disposed, for example, at a position opposite to the housing portion 2. When the flange portion 3 is annular with corners at four locations, the through-region 36 is preferably formed at one location at each corner of the flange portion 3 when viewed from above, for a total of four locations. The shapes of the through-regions 36 are preferably the same.

[0120] In addition, in the present embodiment, the through region 36 is a concave portion that is concave downward. In addition, the through region 36 is circular in a plan view. Specifically, the through region 36 is a concave portion that is concave downward in a substantially hemispherical shape.

[0121] In the present embodiment, a groove portion 360 is further formed in the concave portion of the through region 36. Specifically, an upper surface 361 of the through region 36 is concave downward, and the groove portion 360 concave downward is provided on the upper surface 361.

[0122] The shape of the groove 360 ​​is, for example, a cross shape that intersects at the lowest point in the through-region 36 (for example, substantially orthogonal at the lowest point here). In other words, the groove 360 ​​has a shape that radially expands 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 extending direction of the groove 360) is, for example, 0.5 mm.

[0123] Next, a sterilization method for an object to be treated using the packaging container of the present invention is described. In one embodiment, the sterilization method includes a food as a content, and as main processes, sequentially performing a food receiving process, a through-hole forming process, a primary sealing process, a sterilization process, and a secondary sealing process. More specifically, Figure 3As shown in the figure, the food storage process, the through hole forming process, the primary sealing process, the degassing process, the sterilization process, the cooling process, the gas replacement process and the secondary sealing process are performed in sequence. The following describes each process of this embodiment. In addition, as a method of this embodiment, the case of using the packaging container 1 of the above embodiment is described.

[0124] First, Figure 4A and Figure 4B As shown, after the food storage step of storing the food F in the packaging container 1 is performed, the through hole forming step is performed, which is a step of forming a through hole 38 penetrating the through area 36 at the inner side of the primary sealing area 31 of the flange portion 3. As the food F, for example, any food such as food delivered on the same day, that is, food cooked and processed in a food factory, or frozen processed food can be used.

[0125] like Figure 5 As shown in FIG. 1 , the through hole 38 of the present embodiment is formed by forming a slit 380 in a portion of the through region 36. In the through hole forming step of the present embodiment, the through region 36 is located below the surrounding region while the outer peripheral edge 363 of the through region 36 is continuous with the surrounding region of the through region 36 in the flange portion 3. In other words, the through region 36 is located below the surrounding region of the through region 36 in the flange portion 3 with the outer peripheral edge 363 of the through region 36 as the boundary.

[0126] In the through-hole forming step of the present 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 adopted: a perforating tool (not shown) having a perforating needle at the tip is used, and the perforating needle is pierced into the through-region 36. The perforating needle is guided by the groove 360 ​​provided in the through-region 36, and pierces to the lowest point of the through-region 36, so that the through-region 36 is 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.

[0127] Then, if Fig. 6A , Figure 6B and Figure 7 As shown in FIG. 1 , after the primary sealing step of sealing the lid member 5 covering the opening 20 of the storage portion 2 with the primary sealing area 31 of the flange portion 3 is performed, a sterilization step is performed in which the heated steam S is circulated into the storage portion 2 through the flow path R formed between the flange portion 3 and the lid member 5 to expose the food F to the heated steam S for sterilization (see FIG. 1 ). Figure 7The primary sealing step of the present embodiment is a step of sealing the outer peripheral portion of the flange portion 3, i.e., the primary sealing region 31, with the cover member 5 in a linear manner in the circumferential direction of the outer peripheral portion of the flange portion 3 (see Fig. 6A ). In addition, in this primary sealing step, the cover member 5 is heat-fused to the primary sealing region 31 by using, for example, a heat sealer (not shown).

[0128] In addition, in this embodiment, a case where a sterilization process is performed using a short-time cooking sterilization device RIC (hereinafter also simply referred to as RIC) manufactured by Higasaka Manufacturing Co., Ltd. Here, the short-time cooking sterilization device RIC (not shown) includes: a processing tank capable of accommodating food packaged in a container as a processing object; a steam supply device for supplying steam to the processing tank; a decompression device for degassing the inside of the processing tank to make it a vacuum state; and a heating device for heating the inside of the processing tank.

[0129] In the present embodiment, a degassing process is performed before the sterilization process to degas the storage section 2. When performing the degassing process, a plurality of packaging containers 1 containing food F and sealed with a cover member 5 are arranged on a tray, and then the trays are stacked in multiple layers in the vertical direction and stored in a processing tank constituting the RIC. After the lid of the processing tank is closed and the processing tank is sealed, the processing tank is degassed until it becomes a vacuum state. After the processing tank is degassed to a vacuum state, the air in the storage section 2 is also degassed through the flow path R, and the storage section 2 is also in a vacuum state like the processing tank.

[0130] In the sterilization step, heating steam S is supplied into the treatment tank and the temperature in the treatment tank is set to, for example, 100° C. to 145° C. The heating steam S supplied into the treatment tank flows from below the flange portion 3 through the flow path R (through hole 38 and gap C) into the storage portion 2. Thus, the food F stored in the storage portion 2 is sterilized by the heating steam S.

[0131] In this embodiment, a cooling step is performed after the sterilization step to cool the food F. In the cooling step, the processing tank is depressurized to discharge the heating steam S, and then the processing tank is made into a vacuum state, thereby evaporating water and removing latent heat from the food F to cool the food F.

[0132] Then, after the cooling process, the lid of the treatment tank is opened and the packaging container 1 containing the food F is taken out together with the tray.

[0133] Then, a gas replacement step is preferably performed. In the gas replacement step, an inert gas such as nitrogen gas or carbon dioxide gas is supplied into the housing portion 2 through the flow path R.

[0134] The gas replacement process and the secondary sealing process of the present embodiment are performed when the packaging container 1 is placed on the metal mold of the heat sealer. The metal mold is provided with a supply path for supplying inert gas through the through hole 38 formed in the container body 4 when the packaging container 1 is placed. In the gas replacement process of the present embodiment, the inert gas is supplied to any one of the four through holes 38 through the supply path of the metal mold. In addition, in the metal mold, an exhaust path for exhausting air is also formed at the position corresponding to the remaining three through holes 38, and the air in the packaging container 1 squeezed by the supplied inert gas is released to the outside through the exhaust path.

[0135] like Fig. 8A and Figure 8B As shown, after the gas replacement step is performed, a secondary sealing step is performed to seal the cover member 5 and the secondary sealing area 32. Thus, a packaged food 6 consisting of the packaging container 1, the cover member 5, and the food F is obtained.

[0136] The secondary sealing step of this embodiment is a step of planarly sealing the outer peripheral portion of the flange 3, that is, the secondary sealing region 32, and the lid member 5. In the secondary sealing step, the lid member 5 is thermally welded to the secondary sealing region 32 using a heat sealer (not shown).

[0137] In this embodiment, the heat sealing machine includes: the metal mold (receiving metal mold) for placing the container body 4 and performing gas replacement, and the metal mold (heat sealing metal mold) for pressing the cover part 5 from above; the secondary sealing process is to quickly seal the packaging container in a state where the packaging container is placed on the receiving metal mold after gas replacement, so that the oxygen concentration in the packaging container 1 can be maintained at an extremely low state.

[0138] In addition, 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 directions during the secondary sealing. Fig. 9 As shown, the through hole 38 is closed and the uppermost portion 33 of the flange is also crushed and the gap C is also closed. In the packaging container 1 of the present embodiment, in the packaging container 1 after secondary sealing, the through hole 38 is closed only by the cover member 5, but when performing secondary sealing, the entire area of ​​the flange portion 3 is pressurized from the top and bottom directions in a state where the flange portion 3 is placed on a metal mold with a flat upper surface, thereby, in the packaging container 1 after secondary sealing, in addition to the cover member 5, the through hole 38 can also be closed by the through area 36 that is deformed (crushed). In addition, when performing secondary sealing, the entire area of ​​the flange portion 3 except the uppermost portion 33 of the flange can also be pressurized from the top and bottom directions. In this case, the gap C is closed in a state where the uppermost portion 33 of the flange is not crushed and remains.

[0139] The above packaging container 1 can be preferably used as a packaging container 1 for the following packaged food 6, for example: after the food F is accommodated in the accommodation portion 2 and a through hole 38 is provided in the through area 36 of the flange portion 3, the cover part 5 and the primary sealing area 31 of the flange portion 3 are sealed, and then, after the heated steam S is circulated into the accommodation portion 2 through the flow path R to sterilize the food F, the cover part 5 and the secondary sealing area 32 of the flange portion 3 are sealed.

[0140] In the packaging container 1, if the through hole 38 is provided inside the primary sealing area 31 of the flange portion 3, the through hole 38 constitutes a part of the flow path R. In addition, when the primary sealing area 31 and the lid member 5 are sealed, a gap C is generated between the flange lower portion 34 and the lid member 5, and the gap C constitutes a part of the flow path R. Therefore, when the food F is sterilized, the heating steam S flows from the lower side of the flange portion 3 through the flow path R constituted by the through hole 38 and the gap C into the storage portion 2, thereby sterilizing the food F in the storage portion 2.

[0141] In particular, in the packaging container 1, since the upper surface 330 of the uppermost portion of the flange is located above the upper surface 340 of the lower portion of the flange, the uppermost portion 33 of the flange maintains the gap C included in the flow path R when the food F is sterilized. Therefore, the heating steam S can flow into the storage portion 2 while the gap C is reliably maintained without being closed by the uppermost portion 33 of the flange.

[0142] Moreover, in the packaging container 1, the cover member 5 is located above the flow path R, that is, the flow path R is not exposed on the cover member 5, so it is difficult for fallen bacteria to be mixed into the packaging container 1 through the flow path R. In addition, the flow path R is closed by sealing the secondary sealing area 32 and the cover member 5, so the packaging container 1 can completely enclose the food F through the secondary sealing of the cover member 5 and the container body 4.

[0143] In the packaging container 1 of the present embodiment, if the through hole 38 is provided by forming a slit 380 in a part of the through region 36 (see Figure 5 ), when forming the through hole 38, a part of the flange portion 3 will not be broken, and fragments of the flange portion 3 will not be generated. Therefore, the fragments of the flange portion 3 can be prevented from mixing into the receiving portion 2.

[0144] In addition, in the packaging container 1 of the present embodiment, since the through region 36 is a concave portion that is concave downward (see Figure 2 ), therefore, when forming the through hole 38, by piercing the concave through region 36 with a piercing needle, the pierced portion of the through region 36 is kept at a position lower than other regions of the flange portion 3 (refer to Figure 5), it is not easy to return upward from the state located below. This can prevent the through hole 38 from being closed, and the through state of the through hole 38 can be maintained until the secondary sealing area of ​​the flange portion 3 and the cover member 5 are sealed.

[0145] Furthermore, in the packaging container 1 of the present embodiment, since the through area 36 (see Figure 1A ), if a through hole 38 is provided at this position, the gas is allowed to flow from both sides of the housing portion 2 through the through hole 38 (refer to Figure 4A ), which can suppress uneven heating of food F.

[0146] In addition, the container body 4 and the cover member 5 used in this embodiment preferably have a gas barrier layer. That is, the container body 4 and the cover member 5 are preferably composed of a multilayer structure including at least one oxygen barrier layer. By providing the container body 4 and the cover member 5 with a gas barrier layer, the proliferation of aerobic bacteria after sterilization can be more effectively suppressed, so the quality retention period achieved in each embodiment can be further extended. As the gas barrier layer, it is conceivable to use an oxygen barrier layer.

[0147] The oxygen barrier layer is a layer having a function of preventing gas from penetrating, and is, for example, a layer having an oxygen permeability of 100cc. 20μm / (m2.day.atm) or less, preferably 50cc. 20μm / (m2.day.atm) or less, and more preferably 10cc. 20μm / (m2.day.atm) or less, as measured under the conditions of 20°C and 65%RH in accordance with JIS-K7126-2 (2006) Part 2 (isobaric method). Here, the oxygen permeability of "10cc. 20μm / (m2.day.atm)" means that in a 20μm barrier material (meaning the case where it is composed of the oxygen barrier layer alone), the amount of oxygen permeation per day under one atmosphere of oxygen is 10cc.

[0148] The oxygen barrier layer includes, for example, ethylene-vinyl alcohol copolymer (hereinafter also referred to as "EVOH (Ethylene Vinyl Alcohol Copolymer)"), a composite structure containing phosphorus and a polyvalent metal element, processed starch, polyamide, polyester, polyvinylidene chloride, acrylonitrile copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl alcohol, inorganic layered compound, inorganic vapor-deposited layer, metal foil and other gas barrier materials. In particular, the oxygen barrier layer preferably contains EVOH, polyamide and processed starch or a combination thereof because of good oxygen barrier properties and melt formability, and more preferably contains EVOH because of particularly excellent melt formability.

[0149] (EVOH)

[0150] 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 a well-known method. Examples of vinyl esters that can be used in this method include: vinyl acetate, vinyl formate, vinyl propionate, trimethylacetic acid vinyl ester, and fatty acid vinyl esters such as vinyl versatate.

[0151] In the present invention, the ethylene unit content of EVOH is preferably, for example, 20 mol% or more, 22 mol% or more, or 24 mol% or more. In addition, the ethylene unit content of 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 be improved. When the ethylene unit content is 60 mol% or less, the oxygen barrier properties tend to be improved. The ethylene unit content in such EVOH can be measured, for example, by nuclear magnetic resonance (NMR: Nuclear Magnetic Resonance).

[0152] In the present invention, the saponification degree of the vinyl ester component of EVOH is preferably, for example, 80 mol% or more, 90 mol% or more, or 99 mol% or more. By making the saponification degree 80 mol% or more, for example, the oxygen barrier property of the above-mentioned oxygen barrier layer can be improved. On the other hand, the saponification degree of the vinyl ester component of EVOH can be, for example, less than 100% or less than 99.99%. The saponification degree of EVOH can be calculated by measuring the peak area of ​​hydrogen atoms contained in the vinyl ester structure and the peak area of ​​hydrogen atoms contained in the vinyl alcohol structure by 1H-NMR measurement. By making the saponification degree of EVOH within the above range, good oxygen barrier properties can be imparted to the oxygen barrier layer constituting the container body 4 or the cover part 5.

[0153] In addition, within the scope of not hindering the purpose of the present invention, EVOH may also have units derived from other monomers other than ethylene and vinyl esters and saponified products thereof. In the case where EVOH has such other monomer units, the content of the 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. Moreover, in the case where EVOH has units derived from the other monomers, the content thereof is, for example, 0.05 mol% or more or 0.1 mol% or more.

[0154] Examples of other monomers that may be present in such EVOH include olefins such as propylene, butene, pentene, and hexene; 3-acyloxy-1-propylene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diacyloxy-2-methyl-1-butene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1 Ester-containing alkenes such as 1-hexene, 6-acyloxy-1-hexene, 5,6-diacyloxy-1-hexene, 1,3-diacetoxy-2-methylenepropane, or their saponified products; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or their anhydrides, salts, or monoalkyl esters or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, or their salts; vinyl silane compounds such as vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(β-methoxy-ethoxy) silane, and γ-methacryloxypropyl trimethoxysilane; alkyl vinyl ethers, vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinylidene chloride, etc.

[0155] The EVOH may be EVOH modified by means of urethanization, acetalization, cyanoethylation, oxyalkyleneization, etc. The EVOH modified in this way tends to improve the melt moldability of the oxygen barrier layer.

[0156] As EVOH, two or more EVOHs different in ethylene unit content, saponification degree, copolymer components, presence or absence of modification, type of modification, etc. may be used in combination.

[0157] EVOH can be obtained by known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In one embodiment, bulk polymerization or solution polymerization, which can be performed without a solvent or in a solution such as an alcohol, is used.

[0158] The solvent used in the solution polymerization method is not particularly limited, and is, for example, an alcohol, preferably a lower alcohol such as methanol, ethanol, or propanol. The amount of the solvent in the polymerization reaction solution can be selected with reference to the viscosity average polymerization degree of the target EVOH or the chain transfer of the solvent, and the mass ratio of the solvent to the total monomers (solvent / total monomers) contained in the reaction solution is, for example, 0.01 to 10, preferably 0.05 to 3.

[0159] In addition, examples of the catalyst used in the above-mentioned polymerization include: azo initiators such as 2,2-azobisisobutyronitrile, 2,2-azobis(2,4-dimethylvaleronitrile), 2,2-azobis-(4-methoxy-2,4-dimethylvaleronitrile), and 2,2-azobis-(2-cyclopropylpropionitrile); and organic peroxide initiators such as isobutyryl peroxide, cumyl peroxyneodecanoate, diisopropyl peroxycarbonate, di-n-propyl peroxydicarbonate, tert-butyl peroxyneodecanoate, lauroyl peroxide, benzoyl peroxide, and tert-butyl hydroperoxide.

[0160] The polymerization temperature is preferably 20° C. to 90° C., more preferably 40° C. to 70° C. The polymerization time is preferably 2 hours to 15 hours, more preferably 3 hours to 11 hours. The polymerization rate is preferably 10% to 90% relative to the vinyl ester of the preparation, more preferably 30% to 80%. The resin content in the solution after polymerization is preferably 5% to 85%, more preferably 20% to 70%.

[0161] In the above polymerization, after a predetermined polymerization time or after a predetermined polymerization rate is reached, a polymerization inhibitor may be added as necessary, and unreacted ethylene gas may be evaporated to remove unreacted vinyl ester.

[0162] Next, an alkali catalyst is added to the copolymer solution to saponify the copolymer. The saponification method may be a continuous method or a batch method. Examples of the alkali catalyst that can be added include sodium hydroxide, potassium hydroxide, and alkali metal alcoholates.

[0163] EVOH after saponification contains alkali catalyst, by-product salts such as sodium acetate or potassium acetate, other impurities, etc. Therefore, it is preferable to remove these substances by neutralization or washing as needed. Here, when washing EVOH after saponification with water (e.g., ion exchange water) that contains almost no predetermined ions (e.g., metal ions, chloride ions), by-product salts such as sodium acetate or potassium acetate may not be completely removed, but may be partially left.

[0164] EVOH may also contain other thermoplastic resins, metal salts, acids, boron compounds, plasticizers, fillers, anti-caking agents, lubricants, stabilizers, surfactants, colorants, ultraviolet absorbers, antistatic agents, desiccants, crosslinking agents, various fiber reinforcements, and other components. Metal salts and acids are preferably contained because the oxygen barrier layer has good thermal stability or good adhesion to other resins.

[0165] From the viewpoint of improving interlayer adhesion, the above-mentioned metal salt is preferably an alkali metal salt, and from the viewpoint of improving thermal stability, an alkaline earth metal salt is preferably used. In the case where EVOH contains a metal salt, its content is converted to the metal atom of the metal salt relative to EVOH, for example, more than 1 ppm, more than 5 ppm, more than 10 ppm, or more than 20 ppm. In addition, in the case where EVOH contains a metal salt, its content is converted to the metal atom of the metal salt relative to EVOH, for example, less than 10000 ppm, less than 5000 ppm, less than 1000 ppm, or less than 500 ppm. By making the content of the metal salt within the range formed by the above-mentioned lower limit and upper limit, there is a tendency to be able to well maintain the interlayer adhesion of the above-mentioned oxygen barrier layer, and to well maintain the thermal stability of EVOH when the container body 4 is recycled.

[0166] As the above-mentioned acid, for example, carboxylic acid compounds, phosphoric acid compounds, etc. can be cited. These acids are useful from the viewpoint of improving the thermal stability of EVOH when melt-molding. When EVOH contains a carboxylic acid compound, the content of carboxylic acid (i.e., the content of carboxylic acid in the dry composition containing the oxygen barrier layer of EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 50 ppm or more. In addition, the content of the carboxylic acid compound is, for example, 10000 ppm or less, 1000 ppm or less, or 500 ppm or less. When EVOH contains a phosphoric acid compound, the content of phosphoric acid (i.e., the phosphate conversion content of the phosphoric acid compound containing the oxygen barrier layer of EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 30 ppm or more. In addition, the content of the phosphoric acid compound is, for example, 10000 ppm or less, 1000 ppm or less, or 300 ppm or less. By making EVOH contain a carboxylic acid compound or a phosphoric acid compound within the above range, there is a tendency that the thermal stability of EVOH during melt molding becomes good.

[0167] When EVOH contains the above-mentioned boron compound, its content (i.e., the boron conversion content of the boron compound in the dry composition of the oxygen barrier layer containing EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 50 ppm or more. In addition, the content of the boron compound is, for example, 2000 ppm or less, 1000 ppm or less, or 500 ppm or less. When EVOH contains a boron compound or a phosphoric acid compound within the above-mentioned range, there is a tendency that the thermal stability of EVOH during melt molding becomes good.

[0168] The method for making the oxygen barrier layer containing EVOH contain the above-mentioned carboxylic acid compound, phosphoric acid compound or boron compound is not particularly limited. For example, these compounds can be added and kneaded when the composition containing EVOH is granulated. The method of adding the above-mentioned carboxylic acid compound, phosphoric acid compound or boron compound is not particularly limited, and the following can be cited: a method of adding in the form of dry powder; a method of adding in a paste state impregnated with a specified solvent; a method of adding in a state suspended in a specified liquid; a method of adding as a solution dissolved in a specified solvent; a method of immersing it in a specified solution, etc. In particular, from the reason that these compounds can be uniformly dispersed in EVOH, it is preferred to adopt a method of adding as a solution dissolved in a specified solvent and a method of immersing it in a specified solution. The solvent used in such a method is not particularly limited. Considering the solubility, cost, ease of handling, safety of the working environment, etc. of these compounds added as additives, water is preferred.

[0169] 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" used in this specification refers to the component with the largest mass % among the components constituting the oxygen barrier layer.

[0170] In the case where 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. In addition, 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" used in this specification refers to the value obtained by dividing the total thickness of the oxygen barrier layer containing the above-mentioned EVOH as a main component contained in the multilayer structure by the number of layers of the oxygen barrier layer. By making the average thickness of the oxygen barrier layer within the above range, the durability, flexibility, and appearance characteristics of the container body 4 or the cover member 5 constituting the packaging container of the present invention tend to become good.

[0171] (Composite structure containing phosphorus and polyvalent metal elements)

[0172] A composite structure containing phosphorus and a polyvalent metal element has a barrier layer formed by the reaction of 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 applying the coating agent on a substrate to react the polyvalent metal compound with the phosphorus compound. Here, when M represents the polyvalent metal atom, 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 of 1080cm-1 to 1130cm-1, and in the infrared absorption spectrum of the composite structure, the maximum absorption wave number in the region of 800cm-1 to 1400cm-1 is preferably in the range of 1080cm-1 to 1130cm-1. When the maximum absorption wave number of the composite structure is within the above range, the composite structure tends to have excellent oxygen barrier properties.

[0173] The substrate to which the coating agent is applied is not particularly limited, and examples thereof include: resins such as thermoplastic resins and thermosetting resins; fiber aggregates such as cloth and paper; wood; glass, etc. In particular, thermoplastic resins and fiber aggregates are preferred, and thermoplastic resins are more preferred. The form of the substrate is not particularly limited, and may be a layered form such as a film or a sheet. As the substrate, a material composed of a thermoplastic resin film and paper is more preferred, and a thermoplastic resin film is more preferred. As the thermoplastic resin film, polyester is preferred, and polyethylene terephthalate is more preferred because it can impart good mechanical strength to the composite structure.

[0174] The polyvalent metal element is not particularly limited as long as it is a polyvalent metal element with which two or more molecules of phosphorus compounds can react, and any element can be used. For example, the polyvalent metal element can be a semi-polyvalent metal element. Examples of polyvalent metal elements include magnesium, calcium, zinc, aluminum, silicon, titanium, zirconium and the like, and aluminum is particularly preferred.

[0175] The compound of the polyvalent metal element is not particularly limited as long as it can react with the phosphorus compound to form a composite structure, and any compound can be used. In addition, the polyvalent metal compound can be used as a solution dissolved in a solvent, or as a dispersion in which microparticles of the polyvalent metal compound are dispersed in a solvent, for example, an aqueous solution containing aluminum nitrate can be used as the polyvalent metal compound.

[0176] Furthermore, microparticles of a polyvalent metal compound can also be dispersed in water or an aqueous solvent and used as a dispersion. As such a dispersion, a dispersion of aluminum oxide microparticles is preferred. Usually, microparticles of a polyvalent metal oxide have hydroxyl groups on their surfaces, and due to the presence of hydroxyl groups, they can react with the above-mentioned phosphorus compound to form the above-mentioned bonds. Microparticles of a polyvalent metal oxide can be synthesized, for example, by using a compound in which a hydrolyzable characteristic group is bonded to a metal atom as a raw material, hydrolyzing it and condensing the hydrolysis product. Examples of raw materials include aluminum chloride, aluminum triethanolate, and aluminum isopropoxide. Methods for condensing the above-mentioned hydrolysis product include, for example, liquid phase synthesis methods such as the sol-gel method. In addition, the microparticles of a polyvalent metal oxide preferably have, for example, a spherical, flat, polyhedral, fibrous or needle-shaped morphology, and preferably have a fibrous or needle-shaped morphology for the reason that oxygen barrier properties can be improved. Moreover, in order to improve oxygen barrier properties and transparency, the average particle size of the polyvalent metal oxide microparticles is preferably greater than 1 nm and less than 100 nm.

[0177] The phosphorus compound is not particularly limited as long as it can react with a compound of a polyvalent metal to form the above-mentioned bond, and any phosphorus compound can be used. Examples of phosphorus compounds include phosphoric acid compounds and derivatives thereof. Specific examples include phosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid. Examples of the above-mentioned polyphosphoric acid include pyrophosphoric acid, triphosphoric acid, or polyphosphoric acid formed by condensation of four or more phosphoric acids. In addition, examples of derivatives of phosphoric acid compounds include phosphates, esters (e.g., trimethyl phosphate), halides, and dehydrates (e.g., phosphorus pentoxide).

[0178] The phosphorus compound can be used as a solution, for example, an aqueous solution using water as a solvent, or a solution containing a hydrophilic organic solvent such as a lower alcohol solution.

[0179] 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 also be added to the above-mentioned coating agent. Examples of other components include: polymer compounds, metal coordination compounds, viscosity compounds, crosslinking agents, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, etc. Examples of polymer compounds include: polyvinyl alcohol, partially saponified products of polyvinyl acetate, poly(hydroxyethyl) acrylate, polysaccharides (such as starch), acrylic polymers (such as 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 products of ethylene-ethyl acrylate copolymers, etc.

[0180] For example, by applying the above-mentioned coating agent and drying and removing the solvent to obtain a coating film, a multivalent metal compound and a phosphorus compound react to form the above-mentioned bond, and a composite structure containing phosphorus and a multivalent metal element can be formed. The temperature used for the heat treatment is preferably above 110°C, more preferably above 120°C, further preferably above 140°C, and particularly preferably above 170°C. In the case where the temperature used for the heat treatment is relatively low, more time is required to form sufficient bonds, which sometimes leads to reduced production efficiency. The upper limit of the temperature used for the heat treatment varies depending on the type of substrate film, for example, 240°C or 220°C. In addition, the time required for the heat treatment is, for example, more than 0.1 seconds, more than 1 second, or more than 5 seconds. In addition, the time required for the heat treatment is, for example, less than 1 hour, less than 15 minutes, or less than 5 minutes. In addition, such a heat treatment can also be carried out in any environment under an atmospheric environment, a nitrogen environment, or an argon environment.

[0181] The lower limit of the average thickness of a single layer of an oxygen barrier layer containing a composite structure containing phosphorus and a polyvalent metal element as a 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 containing phosphorus and a polyvalent metal element as a 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 containing phosphorus and a polyvalent metal element as a main component" used in this specification refers to the value obtained by dividing the total thickness of the oxygen barrier layer containing the composite structure as a main component contained in the multilayer structure by the number of layers of the oxygen barrier layer. When the average thickness of a single layer of the above-mentioned oxygen barrier layer is less than the above-mentioned lower limit, it is difficult to form a layer with uniform thickness, which may sometimes lead to a decrease in the durability of the obtained multilayer structure. When the average thickness of a single layer of the above-mentioned oxygen barrier layer is higher than the above-mentioned upper limit, the softness, stretchability, thermal formation, etc. of the obtained multilayer structure are sometimes reduced.

[0182] (Processed starch)

[0183] The starch used as the raw material of the processed starch is not particularly limited, and examples thereof include starches made from wheat, corn, cassava, potato, rice, oats, arrowroot starch, and peas. The starch is preferably high-amylose starch, and more preferably high-amylose corn starch and high-amylose cassava starch.

[0184] The processed starch is preferably a starch that is chemically modified by replacing the hydroxyl group of the above-mentioned starch with a functional group that is an ether, an ester or a combination thereof. As the processed starch, it is preferably a starch that is modified by a hydroxyalkyl group containing 2 to 6 carbon atoms, or a starch that is modified by reacting the above-mentioned starch with a carboxylic anhydride. In the case where the processed starch is a starch that is modified by a hydroxyalkyl group containing 2 to 6 carbon atoms, as a substituent of the above-mentioned processed starch, it is preferably a functional group having 2 to 4 carbon atoms, for example, it is preferably a hydroxyethyl or hydroxybutyl group that can generate a hydroxyethyl substituent. In addition, in the case where the processed starch is a starch that is modified by reacting the above-mentioned starch with a carboxylic anhydride, as a functional group, it is preferably a butyrate or a lower homologue, more preferably an acetate. In order to manufacture ester derivatives, dicarboxylic anhydrides such as maleic acid, phthalic acid or octenyl succinic anhydride can also be used.

[0185] As the modified starch, hydroxypropylated amylose containing a hydroxypropyl group is preferred, and hydroxypropylated high amylose starch is more preferred.

[0186] The degree of substitution of the modified starch is represented by the average number of substituents per unit of anhydrous glucose, and generally has a maximum value of 3. The degree of substitution of the modified starch is preferably 0.05 or more and less than 1.5.

[0187] The processed starch may contain other starches. Examples of other starches include a mixture of high-amylose starch and low-amylose starch.

[0188] The processed starch may also contain water. Water can function as a plasticizer relative to the processed starch. The water content is, for example, 20% by mass or less or 12% by mass or less. The moisture content of the oxygen barrier layer containing the processed starch as the main component is usually the equilibrium moisture content in the relative humidity under the use environment.

[0189] The processed starch may also contain one or more water-soluble polymers. The water-soluble polymer is not particularly limited, and examples thereof include polyvinyl acetate, polyvinyl alcohol, or a combination thereof. Polyvinyl alcohol is particularly preferred. The content of the one or more water-soluble polymers is, for example, 20% by mass or less or 12% by mass or less. In addition, the content of the one or more water-soluble polymers is, for example, 1% by mass or more or 4% by mass or more.

[0190] The processed starch may also contain one or more plasticizers. The plasticizer is not particularly limited, and is preferably a polyol. Examples of polyols include sorbitol, glycerol, maltitol, xylitol, and combinations thereof. The content of the one or more plasticizers in the processed starch is, for example, 20% by mass or less or 12% by mass or less.

[0191] The processed starch may further contain a lubricant. Examples of lubricants include fatty acids having 12 to 22 carbon atoms, fatty acid salts having 12 to 22 carbon atoms, and combinations thereof. The content of the lubricant in the processed starch is, for example, 5% by mass or less.

[0192] The average thickness of a single layer of the oxygen barrier layer containing processed starch as the main component is, for example, more than 10 μm or more than 100 μm. The average thickness of a single layer of the oxygen barrier layer containing processed starch as the main component is, for example, less than 1000 μm or less than 800 μm. In addition, the term "the average thickness of a single layer of the oxygen barrier layer containing processed starch as the main component" used in this specification refers to the value obtained by dividing the total thickness of the entire oxygen barrier layer containing the above-mentioned processed starch as the main component contained in the multilayer structure by the number of layers of the oxygen barrier layer. When the average thickness of a single layer of the above-mentioned oxygen barrier layer is less than the above-mentioned lower limit, it is difficult to form a layer of uniform thickness, which sometimes leads to a decrease in the durability of the obtained multilayer structure. If the average thickness of a single layer of the above-mentioned oxygen barrier layer is higher than the above-mentioned upper limit, the softness, stretchability, thermal formation, etc. of the obtained multilayer structure are sometimes reduced.

[0193] (Inorganic layered compounds)

[0194] The barrier layer containing an inorganic layered compound is a layer that exhibits barrier properties due to the inorganic layered compound when the inorganic layered compound is dispersed in a thermoplastic resin. The thermoplastic resin used for the barrier layer containing an inorganic layered compound is not particularly limited, and examples thereof include polyamide and ethylene-vinyl alcohol copolymer.

[0195] Examples of the inorganic layered compound include swelling mica, clay, montmorillonite, smectite, hydrotalcite, etc. The inorganic layered compound may be an organically modified inorganic layered compound that has been subjected to an organic treatment.

[0196] The inorganic layer compound is composed of plate-like crystals, and has any appearance such as circular, non-circular, elliptical, substantially oblong, or substantially circular. The inorganic layer compound preferably has a plate-like crystal whose average length of the long side, which can be measured by an electron microscope, satisfies a predetermined range.

[0197] The average length of the long side of the inorganic layered compound is preferably more than 70nm, more preferably more than 80nm, and further preferably more than 90nm. The inorganic layered compound is oriented in the film surface by the stress produced during stretching, but when the average length of the long side of the inorganic layered compound does not reach 70nm, the degree of orientation is insufficient, and sufficient oxygen penetration performance cannot be obtained sometimes. On the other hand, the average length of the long side of the inorganic layered compound can be below 2000nm.

[0198] Furthermore, the inorganic layered compound preferably does not contain coarse substances having a thickness exceeding 2 μm. When the inorganic layered compound contains coarse substances having a thickness exceeding 2 μm, transparency or stretchability may be reduced.

[0199] The content of the inorganic stratiform compound in the barrier layer containing the inorganic stratiform compound is preferably 0.3 to 20% by mass based on the mass of the barrier layer.

[0200] (Inorganic vapor deposition layer)

[0201] The inorganic deposited layer is a barrier layer obtained by, for example, depositing an inorganic substance on a substrate. Examples of substrates that can constitute the inorganic deposited layer include: resins such as thermoplastic resins and thermosetting resins; fiber aggregates such as cloth and paper; wood; glass, etc. Preferred are thermoplastic resins and fiber aggregates, and more preferably thermoplastic resins. When the substrate is composed of the above resins, its form is preferably a layered form such as a film or a sheet.

[0202] Examples of the thermoplastic resin used for 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; polyarylate; regenerated cellulose; polyimide; polyetherimide; polysulfone; polyethersulfone; polyetheretherketone; ionomer resins, etc. Preferably, at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, nylon-6, and nylon-66.

[0203] When a film composed of a thermoplastic resin is used as the substrate, the substrate may be either a stretched film or a non-stretched film. From the perspective of excellent processing suitability (printing, lamination, etc.) of the obtained multilayer structure, a stretched film is preferred, and a biaxially stretched film is more preferred. The biaxially stretched film may be a biaxially stretched film produced by any one of a simultaneous biaxial stretching method, a sequential biaxial stretching method, and a tubular stretching method.

[0204] Examples of paper that can be used as the substrate include kraft paper, woodfree paper, molded paper, glassine paper, parchment paper, synthetic paper, white board paper, gray-back white board paper, milk carton paper, paper cup paper, and ivory paper.

[0205] When the substrate is in a layered form, 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, from the viewpoint of improving the mechanical strength and processability of the obtained multilayer structure.

[0206] Examples of inorganic substances 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 nitride oxides such as silicon oxynitride; metal carbonitrides such as silicon carbonitride, etc. In view of excellent barrier properties to oxygen or water vapor, an inorganic vapor-deposited layer formed of any one of aluminum, aluminum oxide, silicon oxide, magnesium oxide, and silicon nitride, or a combination thereof, is preferred.

[0207] The method for forming the inorganic vapor deposition layer is not particularly limited, and examples thereof include physical vapor deposition methods such as vacuum vapor deposition (such as resistance heating vapor deposition, electron beam vapor deposition, molecular beam epitaxy, etc.), ion plating, sputtering (dual magnetron sputtering, etc.); chemical vapor deposition methods such as thermal chemical vapor deposition (such as catalytic chemical vapor deposition), photochemical vapor deposition, plasma chemical vapor deposition (such as capacitive coupled plasma, inductively coupled plasma, surface wave plasma, electron cyclotron resonance plasma, etc.), atomic layer deposition, and organic metal vapor deposition.

[0208] The thickness of the inorganic vapor-deposited layer varies depending on the type of components that constitute the inorganic vapor-deposited layer, and is preferably 0.002μm to 0.5μm, more preferably 0.005μm to 0.2μm, and further preferably 0.01μm to 0.1μm. Within this range, the thickness at which the barrier properties and mechanical properties of the multilayer structure become good can be selected. When the thickness of the inorganic vapor-deposited layer is less than 0.002μm, the reproducibility of the barrier properties of the inorganic vapor-deposited layer to oxygen and water vapor tends to decrease, and there may be situations where the inorganic vapor-deposited layer does not show sufficient barrier properties. In addition, when the thickness of the inorganic vapor-deposited layer exceeds 0.5μm, the barrier properties of the inorganic vapor-deposited layer tend to be easily reduced when the multilayer structure is stretched or bent.

[0209] (metal foil)

[0210] Metal foil is a single-layer or multi-layer structure composed of a metal having excellent ductility. Examples of the metal contained in the metal foil include aluminum. The metal foil has, for example, the form of aluminum foil or aluminum tape.

[0211] According to the packaging container having the above-described oxygen barrier layer, it is possible to prevent the intrusion of oxygen and to maintain the quality of the sterilized contents housed therein for a longer period of time.

[0212] In addition, the packaging container of the present invention is not limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the present invention. For example, the structure of other embodiments can be added to the structure of a certain embodiment, and a part of the structure of a certain embodiment can be replaced with the structure of another embodiment. Moreover, a part of the structure of a certain embodiment can also be deleted.

[0213] The flange uppermost portions 33A and 33B in the above-mentioned embodiment are both convex portions whose height (dimension in the vertical direction) is smaller than the outer diameter when viewed from above, but the present invention is not limited thereto. As shown in FIGS. 10 and 11 , it is also conceivable to provide a third flange uppermost portion 33C having a height substantially equal to the outer diameter when viewed from above on the flange portion 3. The third flange uppermost portion 33C is circular when viewed from above.

[0214] The through hole 38 in the above embodiment is formed by piercing the through region 36 of the flange 3 with a piercing needle (ie, rupturing the through region 36 ), but the present invention is not limited thereto. For example, the through hole 38 may be formed by punching the through region 36 of the flange 3 .

[0215] like Fig. 12A and Fig. 12B As shown, if the through hole 38 is formed by punching the through area 36 of the flange 3 in the through hole forming step, the through area 36 will be removed from the flange 3. In this configuration, the flow of gas to the through hole 38 is not hindered by the through area 36 from the time the through hole forming step is performed to the time the secondary sealing area 32 is sealed, so the heating steam S can flow smoothly in the through hole 38.

[0216] In the packaging container 1 of the above embodiment, the flange uppermost 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 flange uppermost portion 33 is separated from the primary sealing region 31, but the flange uppermost 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 structure, at least one of the plurality of flange uppermost portions 33 is located outside the through-region 36. For example, the flange uppermost portion 33 may be considered to have a fourth flange uppermost portion 33D, which is located outside the through-region 36 and serves as the primary sealing region 31.

[0217] The flange uppermost portion 33 may also be a fourth flange uppermost portion 33D of a convex strip. In addition, in the flange uppermost portion 33, its upper surface (flange uppermost portion upper surface 330) may also be a flat surface like the upper surface of the fourth flange uppermost portion 33D (see Fig. 12B). When the uppermost portion 33 of the flange is a convex strip, for example, it can be continuously provided in the circumferential direction of the opening edge 21. Specifically, the uppermost portion 33 of the flange can be considered to be a convex strip continuously provided in the circumferential direction of the opening edge 21 over the entire circumference.

[0218] 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 portion of the flange portion 3. In the structure in which the uppermost portion 33 of the flange also serves as the primary sealing area 31 (see Fig. 12A and Fig. 12B ), such as the state after the secondary sealing process Fig.13A and Fig. 13B As shown, it is conceivable that the area located further inside the primary sealing area 31 in the flange lower portion 34 also serves as the secondary sealing area 32.

[0219] Furthermore, in the packaging container 1 of the above embodiment, the surface sealing is performed in the secondary sealing process, but a line sealing which is continuous all around the circumference of the opening edge 21 may also be performed. Fig.14A and Fig. 14B In this case, the secondary sealing area 32 can be considered as a convex strip protruding upward.

[0220] In this case, the upper surface of the secondary sealing area 32 is located below the upper surface 330 of the flange uppermost portion (the upper surface of the fourth flange uppermost portion 33D which also serves as the primary sealing area 31). Moreover, the flange portion 3 is configured so that when the cover member 5 is sealed with the primary sealing area 31, a gap C is formed between the upper surface of the secondary sealing area 32 and the lower surface of the cover member 5. Thus, between the time after the primary sealing process and the time before the secondary sealing process, that is, when the food F is sterilized, a gap C is generated between the cover member 5 supported by the upper surface 330 of the flange uppermost portion and the flange lower portion upper surface 340, and the first flange upper surface 230 maintains the gap C and reliably maintains the gap C in an unsealed state, so that the heating steam S flows into the storage portion 2 through the flow path R.

[0221] In the above embodiment, the flange portion 3 is provided with a convex portion such as the flange uppermost portion 33, but a concave portion recessed downward, or a concave portion such as Fig.15A and Fig. 15B As shown, the flange portion 3 is provided with a groove portion 39 as the flange lower portion 34. For example, the groove portion 39 can be considered to be continuous in the circumferential direction along the opening edge 21. Specifically, the groove portion 39 can be considered to be continuous in the entire circumference of the opening edge 21 in the circumferential direction.

[0222] In the structure in which the recessed portion is provided in the flange portion 3, the through region 36 may be provided in the recessed portion. For example, it is conceivable to provide the through region 36 in the groove portion 39 of the flange portion 3. Specifically, it is conceivable to provide the through region 36 on a pair of sides opposite to each other across the receiving portion 2 in the groove portion 39 that is continuous throughout the circumference of the opening edge 21. In this case, the through region 36 provided on each side is, for example, arranged at opposite positions across the receiving portion 2. In this structure, if the through hole forming step is performed, the through hole 38 is provided in the groove portion 39 of the flange portion 3.

[0223] In this case, it is also conceivable to provide the primary seal region 31 continuously in the circumferential direction of the opening edge 21 outside the groove portion 39 of the flange portion 3 (flange uppermost portion 33 ). Specifically, the primary seal region 31 is continuous in the circumferential direction of the opening edge 21 over the entire circumference.

[0224] In the above-mentioned structure in which the through region 36 is provided in the groove portion 39 of the flange portion 3 (see Fig.15A and Fig. 15B ),like Fig.16A and Fig. 16B As shown, the secondary sealing area 32 can be considered to be continuously arranged on the inner side of the groove portion 39 of the flange portion 3 along the opening edge 21 in the circumferential direction. Specifically, the secondary sealing area 32 can be considered to be continuous in the circumferential direction of the opening edge 21. In the flange portion 3 having the above structure, the groove portion 39 having the through area 36 is arranged on the inner side of the primary sealing area 31, and then the secondary sealing area 32 is arranged on the inner side of the groove portion 39.

[0225] In addition, the through area 36 may be provided only at a part of the multiple corners of the flange portion 3. For example, Fig.17A As shown, the through area 36 may be provided in pairs at the corners of the flange 3 across the receiving portion 2. In this case, Fig. 17B As shown, the through holes 38 are provided only at a pair of corners of the flange portion 3 that are located across the housing portion 2 .

[0226] Furthermore, the flange uppermost portion 33 may be a fifth flange uppermost portion 33E which is a convex portion of a hemispherical hillock shape. The flange uppermost portion 33 may be in other shapes such as a cone, a truncated cone, a cylinder, a polygonal column, or a polygonal pyramid.

[0227] The bottom plate 22 of the storage portion 2 in the above embodiment is substantially rectangular, but may also be substantially square. The bottom plate 22 may be polygonal, circular, or the like in addition to a quadrilateral.

[0228] In the packaging container 1 of the above embodiment, the flange 3 is provided with the through area 36 and the flange 3 is provided with the through hole 38 by performing the through hole forming step, but the flange 3 may not be provided with the through area 36. Such a structure may be the structure of FIGS. 18 to 21 and the like.

[0229] For example, Fig.18A and Fig.18B As shown, it is also conceivable that the flange portion 3 has a primary sealing area 31 that is sealed with the cover member 5 in a primary sealing process, and when the cover member 5 and the primary sealing area 31 are sealed, a flow path R is formed between the flange portion and the cover member 5 for allowing gas to flow between the outside and the inside of the housing portion 2. In this structure, the uppermost portion 33 of the flange is a convex strip that extends in an elongated shape along the circumference of the opening edge 21 at intervals at the four corners of the flange portion 3. In addition, the uppermost portion 33 of the flange also serves as the primary sealing area 31. Moreover, as shown in FIG. Fig.19A and Fig.19B As shown, a portion of the flange lower portion 34 that is continuously provided over the entire circumference of the opening edge 21 also serves as the secondary sealing region 32 .

[0230] In this case, the upper surface of the primary sealing area 31 (e.g., the upper surface 330 of the upper part of the flange) is located at the uppermost position in the flange upper surface 30, and the upper surface of the secondary sealing area 32 (e.g., a portion of the flange lower upper surface 340 that is continuously provided in the entire circumference of the opening edge 21) is located below the upper surface of the primary sealing area 31 (e.g., the upper surface 330 of the upper part of the flange). In addition, the flange portion 3 is configured so that when the cover member 5 and the primary sealing area 31 are sealed, a gap C is formed between the upper surface of the secondary sealing area 32 (e.g., the upper surface 340 of the lower part of the flange) and the lower surface of the cover member 5, and the gap C becomes a part of the flow path R.

[0231] 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 that seals at least one point. Fig. 20A and Fig. 20B As shown, it is conceivable to provide a plurality of protrusions on the flange portion 3 as the sixth flange uppermost portion 33F, and the sixth flange uppermost portion 33F also serves as the primary sealing area 31. The shape of the flange uppermost portion 33F is, for example, a truncated cone. In addition, it is conceivable that the flange uppermost portion 33F is provided at the four corners of the flange portion 3 and the center of each side of the flange portion 3. In this way, when a 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 steam S flows into the containing portion 2 through the gaps between the primary sealing areas 31 in the circumferential direction, so that a sufficient amount of the heating steam S can flow into the containing portion 2.

[0232] For example, Fig.21A and Fig.21B As shown, a plurality of recesses may be provided in the flange portion 3 as the flange lower portion 34. The flange lower portion 34 is arranged with gaps in the circumferential direction of the opening edge 21, and may be located at the four corners of the flange portion 3, for example. In this case, the uppermost portion 33 of the flange is located at each side of the flange portion 3. In this structure, the uppermost portion 33 of the flange also serves as the primary sealing area 31. In addition, in this structure, after the primary sealing process is performed, a gap C is generated between the lower surface of the cover member 5 and the upper surface 340 of the flange lower portion, and this gap C is located at the four corners of the flange portion 3, so that the heating steam S flows from the four corners of the flange portion 3 into the housing portion 2.

[0233] In the packaging container 1 of the above embodiment, the shapes and sizes of the through holes 38 formed in the flange portion 3 are the same, but they may be different. Fig.22A and Fig. 22B As shown, it is conceivable to provide through holes 38A at a pair of adjacent corners among the four corners of the flange portion 3, and to provide through holes 38B having a size different from that of the through holes 38A at a pair of corners other than the pair of adjacent corners among the four corners of the flange portion 3. The diameter of the through holes 38A is larger than the diameter of the through holes 38B.

[0234] In addition, the flange uppermost portion 33 may also be a U-shaped or arc-shaped convex strip when viewed from above. For example, the seventh flange uppermost portion 33G located outside the through hole 38A may be considered to be a U-shaped convex strip when viewed from above. The seventh flange uppermost portion 33G is provided along the outer portion of the periphery of the through hole 38A. In addition, a plurality of (for example, three) fifth flange uppermost portions 33E are provided along the opening edge 21 on the inner side of the through hole 38A. In the packaging container 1, the primary sealing area 31 is the outer peripheral edge of the flange portion 3.

[0235] In this way, on the inner side of the primary sealing area 31, the flange uppermost portion 33 is provided at positions both on the outer side and the inner side of the through hole 38A, so that the flange uppermost portion upper surface 330 supports the cover part 5 on the outer side and the inner side of the through hole 38A, thereby being able to maintain a state in which a gap C is generated between the through hole 38A and the cover part 5, thereby preventing the through hole 38A from being closed.

[0236] In the above embodiment, the groove 39 is provided as the recessed portion in the flange 3, but a dot-shaped recessed portion 39 may be provided. For example, the recessed portion 39 may be provided at the four corners of the flange 3. In addition, the through hole 38B may be provided at the bottom of the recessed portion 39.

[0237] Furthermore, a portion of the flange portion 3 including the through hole 38 may be removed after the secondary sealing step. For example, in the structure in which the through holes 38 are provided at the four corners of the flange portion 3 (see Fig.22A and Fig. 22B ),like Fig.23A and Fig. 23B As shown, it is conceivable to provide a secondary sealing area 32 between the uppermost portion 33E of the flange and the through hole 38, and after the secondary sealing process, cut the flange portion 3 at the cutting line L between the through hole 38 and the secondary sealing area 32. In the structure where the through hole 38 is located between the primary sealing area 31 and the secondary sealing area 32, water droplets are easily retained around the through hole 38 in the flange portion 3, but by removing a portion of the flange portion 3 including the through hole 38, such water droplets can be prevented from affecting the packaging container 1.

[0238] In Fig. 23, the cutting line L is set to cut off the four corners of the flange portion 3, but it can also be set to extend between the through hole 38 and the secondary sealing area 32 and cut continuously around the entire circumference of the opening edge 21. That is, the cutting line L can also be set to cut off the outer peripheral portion of the flange portion 3 including the through hole 38.

[0239] The through-region 36 of the above embodiment is circular when viewed from above, and may also be an elliptical strip, etc. In this case, the through-hole 38 may be a slit, etc. In addition, the through-hole 38 of the above embodiment is formed by forming a slit 380 on the through-region 36 provided with the cross-shaped groove 360 ​​or punching the through-region, but may also be formed by other methods.

[0240] In addition, if Fig.24A and Fig. 24B As shown in FIG. 1 , it is conceivable that each through hole 38 is formed by forming a U-shaped slit 380 in a plan view in the flange portion 3. In this structure, the flange portion 3 has an eighth flange uppermost portion 33H, which is formed by deforming a part of the flange portion 3 (for example, the through region 36) upward with the slit 380 as a boundary, and its upper surface is located at the uppermost of the upper surface 30 of the flange portion 3. In addition, the flow path R is formed between the cover member 5 and the flange portion 3 by the eighth flange uppermost portion 33H. Specifically, a U-shaped slit 380 is formed in the through region 36, and the inner side portion of the U-shaped slit 380 is bent upward more than other regions of the flange portion 3 with a straight line 381 connecting the base ends of the slit 380 as a boundary to form the through hole 38, and the eighth flange uppermost portion 33H is formed. In addition, a second flange uppermost portion 33B may be provided near the through hole 38.

[0241] In addition, if Fig.25A and Fig.25BAs shown, it is conceivable to form a linear crack 380 on the flange portion 3 to form each through hole 38. In this structure, the through area 36 is raised upwards from the area other than the through area 36 of the flange portion 3 with a pair of straight lines 381 extending from both ends of the crack 380 as boundaries, thereby forming the through hole 38 and forming the eighth flange uppermost portion 33H.

[0242] In such a structure in which the through-region 36 is deformed upward more than the region other than the through-region 36 of the flange portion 3 to form the through-hole 38, when the heating steam S flows from the bottom of the flange portion 3 to the receiving portion 2, it is easy to keep the through-region 36 lifted by the heating steam S, and therefore it is easy to maintain the through-hole 38 in an open state.

[0243] In addition, if Fig.26A and Fig.26B As shown, in the structure where the through-region 36 is located above the region other than the through-region 36 of the flange portion 3 to form the through-hole 38 and the eighth flange uppermost portion 33H, the third flange uppermost portion 33C can also be provided near the through-hole 38 .

[0244] Moreover, if Fig.27A and Fig.27B As shown, when the through region 36 is deformed upward, it is preferred to use an auxiliary tool to form a depression at the boundary 382 between the flange portion 3 and the through region 36 from above, and use the depression as a starting point to deform the through region 36 upward. In this case, the boundary 382 of the flange portion 3 becomes easy to bend, and it is easy to keep the through region 36 in a lifted state.

[0245] According to this structure, the eighth flange uppermost portion 33H is formed by deforming a portion of the flange portion 3 with the crack 380 as a boundary, and a flow path R is formed through the eighth flange uppermost portion 33H. Therefore, the heating steam S can flow into the housing portion 2 through this flow path R.

[0246] Moreover, if Fig.28A and Fig.28B As shown in the figure, in the case where the eighth flange uppermost portion 33H is formed when the through hole 38 is formed, only the eighth flange uppermost portion 33H may be provided in the flange portion 3 as the flange uppermost portion 33. According to this structure, even if the flange uppermost portion 33 is not formed separately in addition to the eighth flange uppermost portion 33H in the flange portion 3, the flow path R for the heating steam S to flow can be formed by forming the through hole 38 by forming the slit 380 in the flange portion 3.

[0247] In the structure where the through-hole 38 is formed so that the through-hole region 36 becomes the eighth flange uppermost portion 33H, the through-hole 38 may be formed, for example, by the following steps. Fig.29AAs shown, positioning is performed to form a crack 380 in the flange portion 3, as shown in FIG. Fig.29B As shown, the crack 380 is formed by the auxiliary tool for shearing. Fig.29C As shown, an auxiliary tool for forming a depression is driven into the boundary 382 of the through-region 36, such as Fig.29D As shown, the through region 36 is deformed upward by the impact, and the through hole 38 can be formed.

[0248] like Fig. 30A and Fig. 30B As shown, the through-region 36 is a convex portion protruding upward, and the upper end of the convex portion can also constitute the eighth flange uppermost portion 33H. In addition, the through-region 36 can also be considered to have a curved surface bulging upward, for example. In this through-region 36, the upper end of the curved surface constitutes the eighth flange uppermost portion 33H. The through-region 36 of this embodiment is bowl-shaped. The entire area of ​​the upper surface of the through-region 36 is a curved surface. In addition, the outer periphery of the through-region 36 has an arc-shaped portion and a straight-line portion. In the outer periphery of the through-region 36 of this embodiment, the arc-shaped portion is arranged on the inner side than the straight-line portion. In addition, in this structure, by forming a crack 380 in a portion of the outer periphery of the through-region 36 (for example, the arc-shaped portion) and deforming the through-region 36 upward, as shown in FIG. Fig. 30C As shown, the through region 36 is formed into a curved surface convex upward.

[0249] When the through region 36 is a convex portion protruding upward, the entire upper surface of the convex portion may be a non-curved inclined surface, or only a portion of the upper surface of the convex portion may be a curved surface. Fig.31A and Fig.31B As shown, the upper portion of the upper surface of the through-region 36 is a convex portion of a curved surface that bulges upward, and the upper end of the curved surface constitutes the uppermost portion 33H of the eighth flange. The lower portion of the upper surface of the through-region 36 is an inclined surface. The outer periphery of the through-region 36 is a chamfered rectangle. In addition, in this structure, a crack 380 is formed in a portion of the outer periphery of the through-region 36 (for example, a portion of the outer periphery excluding one side located on the outside, that is, three sides and a pair of corners in the outer periphery of the rectangle), and the through-region 36 is deformed upward, as shown in FIG. Fig.31C As shown, the through region 36 is formed into a curved surface that bulges upward.

[0250] In the structure in which a part of the flange portion 3 deformed upward (for example, the through area 36) is a curved surface bulging upward, when the primary sealing area 31 and the cover part 5 are sealed, the convex curved surface bent upward by forming a crack 380 in the flange portion 3 will not cause damage to the cover part 5, and the cover part 5 can be stably supported.

[0251] In the above embodiment, in the packaging container 1 of Figures 24 to 31, the through region 36 is located above the other regions of the flange portion 3 with the crack 380 as the boundary, but it can also be located below to form the through hole 38. In this case, the portion of the flange portion 3 other than the through region 36 can constitute the flange uppermost portion 33.

[0252] In the packaging container 1 of the above embodiment, the through hole 38 is arranged at the corner of the flange portion 3. Fig.32A As shown in FIG. 1 , the through hole 38 may be arranged in a region other than the corner of the flange portion 3. In addition, the packaging container 1 of the above embodiment includes a receiving portion 2, such as FIG. 32B to FIG. 32C As shown, a plurality of housing sections 2 may be provided. In this case, it is considered that the through hole 38 is disposed between adjacent housing sections 2 (in a region sandwiched by the housing sections 2).

[0253] In the packaging container 1 of the above embodiment, the through area 36 is provided in the flange portion 3, but the through hole 38 may be provided in advance in the flange portion 3 instead of the through area 36. In this case, the manufacturing method of the packaged food 6 does not include the through hole forming step, but includes the food accommodating step, the primary sealing step, the sterilizing step, and the secondary sealing step.

[0254] In the method for manufacturing packaged food of the above-mentioned embodiment, a food storage process, a through-hole forming process, a primary sealing process, a sterilization process, and a secondary sealing process are performed in sequence. However, the food storage process may be performed after the through-hole forming process. In addition, the packaging container 1 may preferably be used as a packaging container 1 for the following packaged food 6: after the through-hole 38 is provided in the through-region 36 of the flange portion 3 and the food F is stored in the storage portion 2, the cover member 5 is sealed with the primary sealing region 31 of the flange portion 3, and then the heated steam S is circulated into the storage portion 2 via the flow path R to sterilize the food F, and then the cover member 5 is sealed with the secondary sealing region 32 of the flange portion 3.

[0255] The flange portion 3 in the above-described embodiment is provided over the entire circumference of the opening edge 21 in the circumferential direction, but may be provided in a discontinuous state (at intervals) in the circumferential direction.

[0256] In the packaging container 1 of the above embodiment, the receiving portion 2 and the flange portion 3 are formed by one component, but they may also be formed by different components. For example, the container body 4 may be formed by forming the receiving portion 2 and the flange portion 3 by different components, and the receiving portion 2 or the flange portion 3 is bonded by an adhesive, thereby connecting the receiving portion 2 and the flange portion 3.

[0257] In addition, in the present invention, various contents can be contained as sterilization objects. The contents are, for example, items that are not desired to be exposed to pollutants such as bacteria, dust, or oxygen during storage or transportation, including food, cosmetics, medical supplies, quasi-medical supplies, medical devices, sanitary supplies, physical and chemical supplies, and biological related supplies. Among them, food is preferred, and food that can maintain its appearance and quality during steam sterilization under high temperature and high pressure (for example, food that is solid when contained) is particularly preferred.

[0258] In addition, the sterilizing gas used in the present invention uses heated steam in the above embodiment, but other gases having a sterilizing effect such as ozone gas, ethylene oxide, formaldehyde, acetic acid, ethylene oxide, chlorine dioxide, etc. may also be used depending on the content.

[0259] In view of the above, according to the present invention, it is possible to provide a packaging container that can be preferably used when sterilizing the contents and that can maintain the quality of the sterilized contents for a long period of time.

[0260] The packaging container of the present invention is a packaging container for sterilization treatment, which is used to expose the contents contained inside to a sterilizing gas for sterilization, and then seal the contents and allow them to circulate. The packaging container of the present invention is provided with a container body, which includes: a receiving portion having an opening at the top and receiving the contents, and a flange portion extending outward from the opening edge of the receiving portion, wherein the flange portion has: a primary sealing area for performing a primary seal with a cover member covering the opening in a primary sealing process; a secondary sealing area for performing a secondary seal with the cover member in a secondary sealing process after the primary sealing; and a flange portion located on the upper surface of the packaging container. A flange uppermost portion at the top of the upper surface of the flange portion; a flange lower portion located lower than the upper surface of the flange uppermost portion in the upper surface; at least one through area located inner than the primary sealing area and provided with a through hole penetrating the flange portion, and the flange portion is constructed as follows: after the cover member and the primary sealing area are sealed, a flow path for gas to flow between the outside and the inside of the housing portion is formed between the cover member supported by the flange uppermost portion and the flange lower portion, and after the cover member and the secondary sealing area are sealed, the flow path is closed.

[0261] The packaging container with this structure is suitable as the following container, that is, after, for example, the contents are accommodated in the accommodation part and a through hole is provided in the through area of ​​the flange part, or after the through hole is provided in the through area of ​​the flange part and the food is accommodated in the accommodation part, the primary sealing area of ​​the cover part and the flange part are sealed, and then after the contents are sterilized by circulating the sterilizing gas into the accommodation part through the flow path, the secondary sealing area of ​​the cover part and the flange part are sealed.

[0262] In this packaging container, when a through hole is provided at a position inside the flange portion than the primary sealing area, the through hole constitutes a part of the flow path. In addition, when the primary sealing area and the cover member are sealed, a gap is generated between the flange lower portion of the flange portion and the cover member, and the gap constitutes a part of the flow path. Therefore, when the contents are sterilized, the sterilizing gas flows from the bottom of the flange portion through the flow path constituted by the through hole and the gap into the receiving portion, thereby sterilizing the contents in the receiving portion.

[0263] In particular, in this packaging container, the upper surface of the uppermost part of the flange is located higher than the upper surface of the lower part of the flange, so when the contents are sterilized, the uppermost part of the flange supports the cover part, so that the gap constituting the flow path can be reliably maintained in a state where it will not be closed through the uppermost part of the flange and the sterilization gas can flow into the storage portion in this state.

[0264] Furthermore, in the packaging container, the cover member is located above the flow path, that is, the flow path is not exposed above the cover member, so even after sterilization by the sterilizing gas, it is difficult for fallen bacteria to be mixed into the container through the flow path. In addition, the flow path is closed by sealing the secondary sealing area with the cover member, so the packaging container can completely enclose the contents by sealing with the cover member.

[0265] Furthermore, in the packaging container, the through hole may be formed by forming a slit in a part of the through region.

[0266] According to this structure, when the through hole is formed in the through area, the flange portion will not be broken to generate the fragments of the flange portion, so that the fragments of the flange portion can be prevented from mixing into the receiving portion.

[0267] The penetration region may include a curved surface that bulges upward, and an upper end of the curved surface constitutes an uppermost portion of the flange.

[0268] According to this configuration, when the primary sealing region and the cover member are sealed, the curved surface can support the cover member without damaging the cover member.

[0269] Furthermore, in the packaging container, the through region may be a recessed portion recessed downward, and the crack is formed in the recessed portion.

[0270] According to this structure, when forming the through hole, by punching the through area recessed downward from the top, the punched portion of the through area is easily kept facing downward than other areas of the flange portion, thereby preventing the through hole from being closed.

[0271] Furthermore, in the packaging container, the flange portion may be provided on the entire periphery of the opening edge of the housing portion, a plurality of the through regions may be provided, and the plurality of the through regions may be arranged at positions facing each other across the housing portion.

[0272] According to this configuration, since the through regions are arranged at opposing positions across the accommodating portion, if through holes are provided at these positions, gas can flow from both sides of the accommodating portion through the through holes, thereby suppressing uneven heating of the food.

[0273] Another packaging container of the present invention is used to expose the contents contained inside to a sterilizing gas for sterilization, and then seal the contents to allow them to circulate. It has a container body, which includes: a receiving portion with an opening at the top and which receives the contents, and a flange portion extending outward from the opening edge of the receiving portion, the flange portion having: a primary sealing area for performing a primary seal with a cover member covering the opening in a primary sealing process; a secondary sealing area for performing a secondary seal with the cover member in a secondary sealing process after the primary sealing, and the flange portion is constructed as follows: after the cover member and the primary sealing area are sealed, a flow path is formed between the flange portion and the cover member for allowing gas to flow between the outside and the inside of the receiving portion, and after the cover member and the secondary sealing area are sealed, the flow path is closed.

[0274] The packaging container of this structure is preferably used as the following container: the contents are accommodated in the storage part and the primary sealing area of ​​the cover member and the flange part is sealed, and then the sterilizing gas is circulated into the storage part through the flow path to sterilize the contents, and then the secondary sealing area of ​​the cover member and the flange part is sealed.

[0275] In this packaging container, when the primary sealing area and the lid member are sealed, sterilizing gas flows from below the flange portion through the flow path into the storage portion when the content is sterilized, thereby sterilizing the content in the storage portion.

[0276] Furthermore, in the packaging container, the cover member is located above the flow path, that is, the flow path is not exposed above the cover member, so even after sterilization by the sterilizing gas, it is difficult for fallen bacteria to mix into the container through the flow path. In addition, the flow path is closed by sealing the secondary sealing area and the cover member, so the packaging container can completely enclose the content by sealing with the cover member.

[0277] Furthermore, in the flange portion of the packaging container, at least one through hole penetrating the flange portion may be provided at a position further inside the primary sealing region, wherein the through hole constitutes a part of the flow path.

[0278] According to this configuration, after the primary sealing step, the sterilizing gas flows from below the flange portion through the through hole forming a part of the flow path into the storage portion, thereby sterilizing the food in the storage portion.

[0279] Furthermore, in the packaging container, the through hole may be formed by forming a slit in a part of the flange portion.

[0280] According to this structure, when the through hole is provided, a part of the flange portion is not broken to generate fragments of the flange portion, so that the fragments of the flange portion can be prevented from mixing into the receiving portion.

[0281] In the packaging container, the flange may include a flange uppermost portion formed by deforming a portion of the flange upward with the slit as a boundary, and the flow path is formed between the lid member supported by the flange uppermost portion and the flange.

[0282] According to this structure, by forming the slit in the flange portion, the through hole and the uppermost portion of the flange can be formed simultaneously.

[0283] Furthermore, in the packaging container, a portion of the flange portion deformed upward may further include a curved surface bulging upward.

[0284] According to this configuration, when the primary sealing region and the cover member are sealed, the curved surface can support the cover member without damaging the cover member.

[0285] Furthermore, in the packaging container, the flange portion may include a flange uppermost portion whose upper surface is located uppermost among upper surfaces of the flange portion, and the flow path is formed between the lid member supported by the flange uppermost portion and the flange portion.

[0286] According to this configuration, during the period from the primary sealing step to the secondary sealing step, that is, when the contents are sterilized, the cover member is supported by the uppermost portion of the flange, so that the sterilizing gas can be more reliably circulated into the storage portion through the formed flow path.

[0287] Furthermore, in the packaging container, the flange portion may be provided on the entire circumference of the opening edge of the receiving portion, and a plurality of through holes may be provided and arranged at positions facing each other across the receiving portion.

[0288] According to this configuration, by causing the gas to flow from both sides of the housing portion through the through holes disposed across the housing portion, it is possible to suppress uneven heating of the food.

[0289] In addition, in the packaging container, it can also be configured that the upper surface of the primary sealing area is located at the top of the upper surface of the flange portion, and the upper surface of the secondary sealing area is located below the upper surface of the primary sealing area, and after the flange portion and the primary sealing area are sealed, a gap is formed between the upper surface of the secondary sealing area and the lower surface of the cover part, and the gap becomes a part of the flow path.

[0290] According to this structure, between the time when the primary sealing process is performed and the time when the secondary sealing process is performed, that is, when the contents are sterilized, since the upper surface of the primary sealing area is located above the upper surface of the secondary sealing area, the primary sealing area maintains the gap that becomes a part of the flow path, so the primary sealing area reliably maintains the gap in an unsealed state, allowing the gas to flow into the storage portion through the through hole.

[0291] Furthermore, in the packaging container, the housing portion may include a bottom plate on which the contents are placed, and the bottom plate may have a concavo-convex shape on an upper surface.

[0292] According to this structure, when the contents are arranged in the storage part, a gap is generated below the contents, so when the sterilizing gas is circulated into the storage part, the sterilizing gas flows not only above the contents but also below them. Therefore, the contents can be sterilized from both above and below by the sterilizing gas.

[0293] The packaging container of the present invention may further include a cover member, wherein the container body and the cover member are composed of a multilayer structure including at least one gas barrier layer.

[0294] According to this configuration, since the container body or the cover member is provided with the gas barrier layer, the sterilized state in the packaging container can be maintained for a longer period of time.

[0295] In view of the above, according to the present invention, it is possible to provide a packaging container which is preferably used when sterilizing the contents and which can maintain the quality of the sterilized contents for a long period of time.

[0296] Description of Reference Numerals

[0297] 1: Packaging container

[0298] 2: Containment Department

[0299] 3: Flange

[0300] 4: Container body

[0301] 5: Cover parts

[0302] 6: Packaged Food

[0303] 20: Opening

[0304] 21: Opening edge

[0305] 22: Bottom plate

[0306] 23: Side wall

[0307] 30: Flange upper surface

[0308] 31: Primary sealing area

[0309] 32: Secondary sealing area

[0310] 33: Top of flange

[0311] 33A: Uppermost portion of first flange

[0312] 33B: Uppermost part of the second flange

[0313] 33C: The uppermost part of the third flange

[0314] 33D: The uppermost part of the fourth flange

[0315] 33E: The uppermost part of the fifth flange

[0316] 33F: Uppermost portion of the sixth flange

[0317] 33G: The top of the seventh flange

[0318] 33H: The uppermost part of the eighth flange

[0319] 34:lower part of flange

[0320] 35: flange lower surface

[0321] 36: Through Area

[0322] 38, 38A, 38B: through hole

[0323] 39: Groove (concave)

[0324] 220: Upper surface of the bottom plate

[0325] 221: Bottom surface of bottom plate

[0326] 222: Bottom plate protrusion

[0327] 223: Bottom plate inclined surface

[0328] 230: Upper surface of the first flange

[0329] 330: Upper surface of the uppermost part of the flange

[0330] 340: Upper surface of flange lower part

[0331] 360: Groove

[0332] 361: Upper surface

[0333] 362: Lower surface

[0334] 363: Outer periphery

[0335] 380: Crack

[0336] 381: Straight Line

[0337] 382: Boundary

[0338] C: Clearance

[0339] F: Food

[0340] L: Cutting line

[0341] R: Circulation Path

[0342] S: Heating steam.

Claims

1. A packaging container for sterilization treatment, which is used to expose the contents contained therein to a sterilizing gas for sterilization, and then seal the contents for circulation, The packaging container includes a container body, the container body including: a receiving portion having an opening at the top and receiving the contents, and a flange portion extending outward from the opening edge of the receiving portion. The flange portion has: a primary sealing region which is primarily sealed with a cover member covering the opening in a primary sealing step; a secondary sealing region, which is secondarily sealed with the cover member in a secondary sealing process after the primary sealing process, thereby completely sealing the contents; The uppermost portion of the flange has an upper surface located at the uppermost position among the upper surfaces of the flange portion; a flange lower portion having an upper surface located below an upper surface of an uppermost portion of the flange; and At least one through area is located further inside than the primary sealing area and is provided with a through hole that penetrates the flange portion, and the flange portion is configured so that, after the cover member and the primary sealing area are sealed, a flow path is formed between the cover member supported by the uppermost portion of the flange and the lower portion of the flange, through which the air in the receiving portion can be degassed to the outside and the sterilizing gas can flow into the receiving portion from the outside, and the flow path is maintained in an open state during the degassing of the receiving portion and the flow of the sterilizing gas into the receiving portion, and the flow path is closed after the cover member and the secondary sealing area are sealed.

2. The packaging container according to claim 1, The through hole is formed by forming a crack in a part of the through region.

3. The packaging container according to claim 2, The through area has a curved surface bulging upward, The upper end of the curved surface constitutes the uppermost portion of the flange.

4. The packaging container according to claim 2, The through region is a concave portion that is concave downward, and the crack is formed in the concave portion.

5. The packaging container according to claim 1, The flange portion is provided around the entire circumference of the opening edge of the receiving portion. A plurality of the through regions are provided, and the through regions are arranged at positions facing each other across the housing portion.

6. A packaging container for sterilizing the contents contained therein by exposing them to a sterilizing gas, and then sealing the contents to allow them to circulate, The packaging container comprises a container body, the container body including: a receiving portion having an opening at the top and receiving the contents, and a flange portion extending outward from the opening edge of the receiving portion; The flange portion has: a primary sealing region which is primarily sealed with a cover member covering the opening in a primary sealing step; a secondary sealing region, wherein the secondary sealing region and the cover member are secondarily sealed in a secondary sealing process after the primary sealing process, 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 so that the air in the receiving portion can be degassed to the outside and the sterilizing gas can flow into the receiving portion from the outside. During the period of degassing the receiving portion and flowing the sterilizing gas into the receiving portion, the flow path is maintained in an open state. After the cover member and the secondary sealing area are sealed, the flow path is closed. The flange portion is provided with at least one through hole penetrating the flange portion on the inner side of the primary sealing region, and the through hole is configured to become a part of the flow path.

7. The packaging container according to claim 6, The through hole is formed by forming a slit in a part of the flange portion.

8. The packaging container according to claim 7, The flange portion has an uppermost flange portion, which is formed by deforming a portion of the flange portion upward with the crack as a boundary. The flow path is formed between the cover member supported by the uppermost portion of the flange and the flange portion.

9. The packaging container according to claim 8, The portion of the flange portion deformed upward has a curved surface that bulges upward.

10. The packaging container according to claim 6 or 7, The flange portion has a flange uppermost portion, the upper surface of which is located at the uppermost position among the upper surfaces of the flange portion, The flow path is formed between the cover member supported by the uppermost portion of the flange and the flange portion.

11. The packaging container according to any one of claims 6 to 9, The flange portion is provided around the entire circumference of the opening edge of the receiving portion. A plurality of the through holes are provided, and the through holes are arranged at positions opposite to each other across the housing portion.

12. The packaging container according to claim 6, The upper surface of the primary sealing area is located at the uppermost position of the upper surface of the flange portion. The upper surface of the secondary sealing area is located lower than the upper surface of the primary sealing area, The flange portion is configured such that, after the cover member and the primary sealing region are sealed, a gap is formed between the upper surface of the secondary sealing region and the lower surface of the cover member. The gap is configured to become a part of the flow path.

13. The packaging container according to any one of claims 1 to 9, The receiving portion includes a bottom plate for placing contents. The upper surface of the bottom plate has a concavoconvex shape.

14. The packaging container according to any one of claims 1 to 9, A cover member is also provided. The container body and the cover member are composed of a multilayer structure including at least one gas barrier layer.

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