TWI887315B - Packaging container for sterilization - Google Patents

Abstract

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

Description

Packaging containers for sterilization

[Cross-reference of related applications]

This application claims priority to Japanese Patent Application No. 2019-223878, and is incorporated by reference into the description of this application.

The present invention relates to a packaging container for sterilization, for example, a packaging container that can be preferably used when packaging and sterilizing food such as vegetables.

Among packaged foods, there are foods that have been conditioned and processed in food factories, etc., and are placed in containers with openings, and are circulated with the top seal or cover applied to the container. However, since packaged foods with top seals or covers are not completely sealed, external gases may invade the container. Therefore, the shelf life of such packaged foods is extremely short, about 1 to 2 days, and there is a problem of extremely high waste rate (poor product yield).

Recently, such packaged foods are circulated in the market, that is, the container and the lid are completely sealed in the container, such as heat-sealed, to extend the shelf life. Some of them have a shelf life of more than 2 weeks by refrigerating.

However, even if the container can be sealed by heat sealing to prevent bacteria from entering from the outside, the inside of the molded container is not completely sterile. Therefore, it is very likely that bacteria in the container will multiply due to changes in the environment during the circulation process. Therefore, in order to extend the shelf life, the working environment in the food factory must be as close to the sterile state as possible, and strict cleanliness management is required. In the past, someone proposed a method of sealing the container body with a cover member in a clean room (sterile room) after heat sterilizing the food in the container (Patent Document 1). For example, the cleanliness of the working environment for processing processed food is also managed to a high level of 10000 or 1000 of the NASA standard clean room. However, when introducing this clean room, there is a problem of extremely high cost in the installation and maintenance of air conditioning equipment.

In addition to food, there are also various objects that need to be sterilized before being circulated in the market as products, so it is required to sterilize these objects efficiently.

[Prior Art Literature]

[Patent Literature]

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

The subject of the present invention is to provide a packaging container that can be preferably used when sterilizing the contents. For example, the subject is to provide a packaging container that can be preferably used in the sterilization of food as an example of the contents, and can extend the quality preservation period of the food.

The packaging container of the present invention is a packaging container for sterilization treatment, which exposes the contents contained therein to a sterilizing gas for sterilization, and then seals the contents and allows them to circulate. The packaging container has a container body, which includes: a container portion having an opening at the top and containing the contents, and a flange portion extending outward from the opening edge of the container portion; the flange portion has: a primary sealing area, which is sealed with a cover member covering the opening in a primary sealing process; a secondary sealing area, which is secondary sealed with the cover member in a secondary sealing process after the primary sealing process; and an uppermost portion of the flange, the upper surface of which is sealed with a seal. The flange portion has a surface located at the top of the upper surface of the flange portion; the flange lower portion has an upper surface located below the upper surface of the uppermost portion of the flange; and at least one through area is located further inward than the aforementioned primary sealing area and is provided with a through hole that penetrates the aforementioned flange portion; and the aforementioned flange portion is configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a flow path for gas to flow between the outside and the aforementioned accommodating portion is formed between the aforementioned cover member and the aforementioned flange lower portion supported by the aforementioned uppermost portion, and after the aforementioned cover member and the aforementioned secondary sealing area are sealed, the aforementioned flow path is closed.

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

The aforementioned through area may also have a curved surface that bulges upward, and the upper end of the aforementioned curved surface may also constitute the uppermost portion of the aforementioned flange.

In addition, in the aforementioned packaging container, the aforementioned through area may also be a concave portion that is concave downward, and the aforementioned crack may also be formed in the concave portion.

In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided on the entire circumference of the opening edge of the aforementioned storage portion, and the aforementioned through-area may also be provided in plural numbers and arranged at opposite positions across the aforementioned storage portion.

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

In addition, in the aforementioned flange portion of the aforementioned packaging container, at least one through hole penetrating the aforementioned flange portion may be provided at a location further inward than the aforementioned primary sealing area, and the aforementioned through hole may also be configured in a manner that becomes a part of the aforementioned flow path.

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

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

Furthermore, in the aforementioned packaging container, a portion of the aforementioned flange portion deformed toward the aforementioned upward direction may also have a curved surface that bulges toward the upward direction.

In addition, in the aforementioned packaging container, the aforementioned flange portion may also have: a flange uppermost portion, whose upper surface is located at the uppermost of the upper surfaces of the flange portion, and the aforementioned packaging container may also form the aforementioned flow path between the aforementioned cover member supported by the flange uppermost portion and the aforementioned flange portion.

In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided on the entire circumference of the opening edge of the aforementioned storage portion, and the aforementioned through holes may also be provided in plurality and arranged at opposite positions across the aforementioned storage portion.

In addition, in the aforementioned packaging container, the upper surface of the aforementioned primary sealing area may also be located at the uppermost of the upper surfaces of the aforementioned flange portion, and the upper surface of the aforementioned secondary sealing area may also be located below the upper surface of the aforementioned primary sealing area. The aforementioned flange portion may also be configured such that after the aforementioned cover member and the aforementioned primary sealing area are sealed, a gap is formed between the upper surface of the aforementioned secondary sealing area and the lower surface of the aforementioned cover member, and the aforementioned gap may also be configured in a manner that becomes a part of the aforementioned flow path.

In addition, in the aforementioned packaging container, the aforementioned storage portion may also include a bottom plate on which the contents are placed, and the upper surface of the aforementioned bottom plate may also have a concave-convex shape.

The packaging container of the present invention may also be equipped with a cover member, and the aforementioned container body and the aforementioned cover member may also be composed of a multi-layer structure including at least one gas barrier layer.

1: Packaging container

2: Storage area

3: Flange

4: Container body

5: Cover components

6: Packaged food

20: Open mouth

21: Opening up

22: Base plate

23: Side wall

30: Flange upper surface (upper surface)

31: Primary sealing area

32: Secondary sealing area

33: Uppermost part of flange

33A: The uppermost part of the first flange (the uppermost part of the flange)

33B: The uppermost part of the second flange (the uppermost part of the flange)

33C: The top of the third flange (top of the flange)

33D: The uppermost part of the fourth flange (the uppermost part of the flange)

33E: The top of the fifth flange (top of the flange)

33F: The uppermost part of the sixth flange (the uppermost part of the flange)

33G: The top of the seventh flange (top of the flange)

33H: The top of the eighth flange (top of the flange)

34: Lower flange

35: flange lower surface

36: Through area

38,38A,38B:Through holes

39: Groove (concave)

220: Upper surface of the bottom plate

221: Bottom surface of the base plate

222: Bottom plate protrusion

223: Bottom plate slope

230: Upper surface of the first flange

330: Upper surface of the uppermost part of the flange

340: Upper surface of the lower flange

360: Groove

361: Upper surface

362: Lower surface

363: Periphery

380: Cracks

381: Straight line

382: Junction

C: Gap

F: Food

L: Cutting line

R: Circulation path

S: Heating steam

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

Figure 1B is a schematic diagram of an embodiment of the aforementioned packaging container, which is a side view of the aforementioned packaging container.

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

Figure 3 is a diagram showing the various steps in the manufacturing method of the aforementioned packaging container.

FIG4A is a schematic diagram of the aforementioned packaging container after the through hole forming process and the food containing process, and is a top view of the aforementioned packaging container.

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

Figure 5 is a cross-sectional view at the V-V position of Figure 4A.

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

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

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

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

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

Figure 9 is a cross-sectional view at the IX-IX position of Figure 8A.

Figure 10A is a schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container.

FIG. 10B is a schematic diagram of another embodiment of the packaging container of the present invention, which is a cross-sectional view at the X-X position of FIG. 10A .

FIG. 11A is a schematic diagram of the aforementioned packaging container after the through hole forming process, and is a top view of the aforementioned packaging container.

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

FIG. 12A is a schematic diagram of another embodiment of the packaging container of the present invention after the primary sealing process, and is a top view of the aforementioned packaging container.

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

FIG. 13A is a schematic diagram of another embodiment of the aforementioned packaging container after the secondary sealing process, and is a top view of the aforementioned packaging container.

FIG. 13B is a schematic diagram of another embodiment of the aforementioned packaging container after the secondary sealing process, and is a cross-sectional view at the XIII-XIII position of FIG. 13A .

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

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

FIG. 15A is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a top view of the aforementioned packaging container.

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

FIG. 16A is a schematic diagram of another embodiment of the aforementioned packaging container after the secondary sealing process, and is a top view of the aforementioned packaging container.

FIG. 16B is a schematic diagram of another embodiment of the aforementioned packaging container after the secondary sealing process, and is a cross-sectional view at the XVI-XVI position of FIG. 16A .

FIG. 17A is a schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

FIG. 17B is a schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container after the through hole forming process.

FIG. 18A is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a top view of the aforementioned packaging container.

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

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

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

FIG. 20A is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a top view of the aforementioned packaging container.

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

FIG. 21A is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a top view of the aforementioned packaging container.

FIG. 21B is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a cross-sectional view at the XXI-XXI position of FIG. 21A.

FIG. 22A is a schematic diagram of another embodiment of the packaging container of the present invention after a primary sealing process, and is a top view of the aforementioned packaging container.

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

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

FIG23B is a schematic diagram of the aforementioned packaging container after the secondary sealing process, and is a cross-sectional view at the position XXIII-XXIII of FIG23A.

FIG. 24A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a top view of the aforementioned packaging container.

FIG. 24B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a cross-sectional view at the position of XXIV-XXIV in FIG. 24A.

FIG. 25A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a top view of the aforementioned packaging container.

FIG. 25B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a cross-sectional view at the position of XXV-XXV in FIG. 25A.

FIG. 26A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a top view showing a variation of FIG. 24A .

FIG. 26B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a partial top view showing a variation of FIG. 25A .

FIG. 27A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a cross-sectional view showing a variation of FIG. 24A .

FIG. 27B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a cross-sectional view showing a variation of FIG. 25A .

FIG. 28A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a top view of the aforementioned packaging container.

FIG28B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a cross-sectional view at the position of XXVIII-XXVIII in FIG28A.

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

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

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

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

FIG. 30A is a schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

FIG. 30B is a schematic diagram of another embodiment of the packaging container of the present invention, which is a cross-sectional view of FIG. 30A .

FIG. 30C is a schematic diagram of another embodiment of the packaging container of the present invention, which is a cross-sectional view after the through-hole forming process.

FIG. 31A is a schematic diagram of another embodiment of the packaging container of the present invention, which is a top view of the aforementioned packaging container before the through hole forming process.

FIG31B is a schematic diagram of another embodiment of the packaging container of the present invention, which is a cross-sectional view of FIG31A.

FIG. 31C is a schematic diagram of another embodiment of the packaging container of the present invention, which is a cross-sectional view after the through-hole forming process.

FIG. 32A is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a schematic diagram showing the first variant.

FIG. 32B is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a schematic diagram showing the second variant.

FIG. 32C is a schematic diagram of another embodiment of the packaging container of the present invention after the through hole forming process, and is a schematic diagram showing the third variant.

The following is a description of an embodiment of the present invention with reference to Figures 1 to 9. Figures 1 and 2 are diagrams showing an embodiment of the packaging container of the present invention. In addition, Figure 3 is a diagram for illustrating an embodiment of the method for manufacturing the packaged food of the present invention, and Figures 4 to 9 are diagrams showing the various steps of the manufacturing method in sequence.

First, the structure of a packaging container of an embodiment of the present invention is described. The packaging container of the present invention is used to sterilize the food contained therein as an example of the content by exposing it to heated steam as an example of the sterilizing gas, and then the content (e.g., food) is sealed to be circulated as packaged food for sterilization. As shown in Figures 1 and 2, the packaging container 1 has a container body 4, and the container body 4 includes: a container portion 2 having an opening 20 at the top, and a flange portion 3 extending outward from the opening edge 21 of the container portion 2.

Hereinafter, the up-down direction in the packaging container 1 is consistent with the up-down direction in Figures 1, 2, 4 to 9. In addition, the inner side and the outer side in the flange portion 3 are consistent with the side of the flange portion 3 close to the opening edge 21 and the side far from the opening edge 21.

As shown in FIG. 1A and FIG. 1B , the container body 4 is a container that can be closed by a cover member. The container body 4 of this embodiment is in the shape of a tray, but may also be in any shape such as a cup shape or a bottle shape. In addition, the material of the container body 4 is 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 this embodiment, the thickness of the flange portion 3 is greater than the thickness of the storage portion 2. In the container body 4 of this embodiment, the storage portion 2 and the flange portion 3 are composed of a single member. Specifically, the container body 4 is formed by forming a thin sheet.

In addition, the cover member of this embodiment is flexible. The cover member is, for example, made of a film material made of a synthetic resin. Specifically, the film material constituting the cover member is a film material made of a plastic that has been biaxially stretched.

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 periphery of the bottom plate 22.

The bottom plate 22 is, for example, a rectangular plate with rounded corners. In addition, the bottom plate 22 has: an upper surface 220 of the bottom plate in contact with the food; and a lower surface 221 of the bottom plate which becomes the surface placed on the placing surface when the container body 4 is placed on the placing surface.

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

Each part of the bottom plate protrusion 222 is arranged at approximately equal or unequal intervals. A steam flow portion for steam flow is formed between a pair of bottom plate protrusions 222, 222, and the bottom plate protrusion 222 supports the contents contained in the container body 4 in a point contact or line contact manner, for example. In addition, the bottom plate protrusion 222 is designed in a manner that the contact area between the bottom plate protrusion 222 and the contents is reduced as much as possible.

In the embodiment shown in FIG. 1A , a plurality of steam flow portions formed between the bottom plate protrusions 222, 222 are arranged at approximately equal intervals. According to this configuration, when the contents (e.g., food) contained in the container body 4 are sterilized by steam, steam can flow in not only from the upper surface and side surface of the contents but also from the lower surface of the contents through the steam flow path formed at the bottom, thereby making it possible to sterilize the contents more evenly and effectively by steam.

Although the height of the bottom plate protrusion 222 does not need to be specifically limited, it is based on the lowest inner surface of the bottom of the container (i.e., the lowest inner surface of the container body 4), for example, 2 mm or more, 3 mm or more, or 4 mm or more. In addition, although the height of the bottom plate protrusion 222 does not need to be specifically limited, it is based on the lowest inner 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 of the lower surface of the content can be more effectively performed.

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

The bottom plate inclined surface 223 is provided to eliminate the corner of the storage portion 2. For example, when taking out the food stored in the storage portion 2, the bottom plate inclined surface 223 prevents the food from being retained near the corner of the bottom plate 22 and makes it easier to take the food out of the storage portion 2. In addition, the bottom plate inclined surface 223 is arranged in a state separated from the bottom plate protrusion 222 by a gap.

The side wall 23 is configured, for example, in such a way that the higher the position is, the wider it is when viewed from above. The upper edge of the side wall 23 constitutes the opening edge 21 of the storage portion 2.

The flange 3 is a portion sealed with the cover member. The flange 3 is, for example, provided around the entire circumference of the opening edge 21. The flange 3 of this embodiment is generally plate-shaped and is configured in a ring shape to surround the accommodating portion 2 when viewed from above. Specifically, the flange 3 is a ring shape having four corners when viewed from above.

In addition, as shown in FIG. 2 , the flange portion 3 has a flange upper surface 30 facing upward and a flange lower surface 35 facing downward. Furthermore, the flange portion 3 has: a primary sealing area 31 sealed with the 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.

The flange portion 3 of this embodiment has a through area 36 (see FIG. 1A ) having a through hole penetrating the flange portion 3. In this embodiment, the through hole, i.e., the through area 36, is located further inward than the primary sealing area 31. The through hole provided in the through area 36 penetrates between the flange lower surface 35 and the flange upper surface 30. In addition, a plurality of through areas 36 are provided in the flange portion 3 of this embodiment.

The number of through-regions 36 provided in the flange 3 may be one, but it is preferred that the flange 3 be provided with both through-holes for gas to flow into the flange 3 and through-holes for gas to flow out of the flange 3, so it is preferred that there be multiple through-regions 36. Specifically, in this flange 3, the same number of through-regions 36 as the number of corners of the flange 3 (for example, four in this embodiment) are provided.

The primary sealing area 31 is a part of the flange 3 and is used to temporarily seal the lid member and the flange 3 through a primary sealing process. The primary sealing process is performed after the food is contained in the containing part 2 and before the contained food is sterilized.

The primary sealing area 31 of this embodiment is located at the outer periphery of the flange 3. In addition, the primary sealing area 31 is continuous in the circumferential direction of the opening edge 21. Specifically, the primary sealing area 31 is located on the outer periphery of the flange 3 and is further inward than the outer periphery, and extends continuously in the circumferential direction. More specifically, the primary sealing area 31 is located on the outer periphery of the flange 3 and is further inward than the outer periphery, and extends continuously in the circumferential direction of the opening edge 21.

The secondary sealing area 32 is the area where the cover member and the flange 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 part 2 is sterilized. The secondary sealing area 32 is at least a part of the flange 3. Furthermore, the secondary sealing area 32 may also include an area that is repeated (same) as the primary sealing area 31. The secondary sealing area 32 of this embodiment is the entire area of the flange 3.

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 FIG. 1B ).

The uppermost portion 33 of the flange is a portion of the upper surface relatively located above. The uppermost surface 330 of the flange in this embodiment is located, for example, about 1 mm or more above the upper surface 340 of the lower portion of the flange. The uppermost portion 33 of the flange can support the cover member above the upper surface 340 of the lower portion of the flange after the primary sealing process and before the secondary sealing process.

Specifically, the uppermost portion 33 of the flange is a convex portion formed by partially pressing the flange portion 3 from the bottom to the top. As a result, the upper surface 330 of the uppermost portion of the flange protrudes upward. The uppermost portion 33 of the flange of this embodiment is hollow, but it can also be solid.

In the flange portion 3 of the present embodiment, flange uppermost portions 33 of different shapes are provided. Specifically, as shown in FIG. 1A , 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 shape on the upper surface 330 of the flange uppermost portion. 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.

In addition, the flange uppermost portion 33 of the present embodiment is disposed near the through area 36. For example, at least one of the flange uppermost portions 33 is disposed further inwardly than the through area 36. All of the flange uppermost portions 33 of the present embodiment are disposed further inwardly than the through area 36. Specifically, a plurality of flange uppermost portions 33 are disposed on the inner side of each through area 36 (for example, each is a pair). The flange uppermost portion 33 is disposed one at the inner side of each through area 36 in a manner corresponding to each through area 36, but after a sealing process is performed once, it is preferred to support the cover member with a plurality of flange uppermost portions 33, so it is preferred to have a plurality of flange uppermost portions 33.

The flange lower portion 34 is a portion located relatively downward relative to the upper surface. The flange lower portion 34 of this embodiment is a portion of the flange portion 3 other than the aforementioned flange uppermost portion 33.

The through area 36 is, for example, arranged at a position opposite to the accommodating portion 2. When the flange portion 3 is annular with corners at four locations, the through area 36 is preferably formed at one location on each corner of the flange portion 3 when viewed from above, for a total of four locations. The shapes of the through areas 36 are preferably the same.

In addition, in this embodiment, the through area 36 is a concave portion that is concave downward. In addition, the through area 36 is circular when viewed from above. Specifically, the through area 36 is a concave portion that is concave downward into a roughly hemispherical shape.

A groove portion 360 is further formed in the concave portion of the through-region 36 of the present embodiment. Specifically, the upper surface 361 of the through-region 36 is concave downward, and a groove portion 360 concave downward is provided on the upper surface 361.

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

Next, the sterilization method of the treatment object using the packaging container of the present invention is described. The sterilization method of one embodiment is to use food as the content, and the main processes are to carry out the food containing process, the through hole forming process, the primary sealing process, the sterilization process and the secondary sealing process in sequence. More specifically, as shown in FIG3, the food containing 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 carried out in sequence. The following describes each process of this embodiment. In addition, the method of this embodiment is described by using the packaging container 1 of the above-mentioned embodiment.

First, as shown in FIG. 4A and FIG. 4B, after the food storage process of storing the food F in the packaging container 1, the through hole forming process is performed, and the through hole forming process is to form the through hole 38 penetrating the through area 36 at the inner side of the primary sealing area 31 of the flange portion 3. The food F can be, for example, food delivered on the same day, that is, food processed in a food factory, or any food such as processed food for children.

As shown in FIG. 5 , the through hole 38 of the present embodiment is formed by forming a crack 380 on a portion of the through area 36. In the through hole forming process of the present embodiment, the through area 36 is located below the surrounding area of the through area 36 of the flange 3 while the outer periphery 363 of the through area 36 is continuous with the surrounding area of the through area 36 of the flange 3. In other words, the through area 36 is located below the surrounding area of the through area 36 of the flange 3 with the outer periphery 363 of the through area 36 as the boundary.

In the through hole forming process of this embodiment, the crack 380 is formed by splitting the through area 36 from above. When forming the crack 380, for example, the following method can be adopted: use a perforation auxiliary tool (not shown in the figure) with a perforating needle at the front end, and pierce the perforating needle into the through area 36. The perforating needle is guided by the groove 360 provided on the through area 36, and pierces to the lowest point of the through area 36, so that the through area 36 is split along the groove 360. As a result, the through area 36 is divided into four parts with the cross-shaped crack 380 as the boundary.

Next, as shown in FIG. 6A, FIG. 6B and FIG. 7, after the primary sealing process of sealing the cover member 5 covering the opening 20 of the container 2 with the primary sealing area 31 of the flange 3, a sterilization process is performed. The sterilization process is to allow heated steam S to flow into the container 2 through the flow path R formed between the flange 3 and the cover member 5, and then expose the food F to the heated steam S for sterilization (refer to FIG. 7). The primary sealing process of this embodiment is a process of linearly sealing the primary sealing area 31 belonging to the outer peripheral part of the flange 3 and the cover member 5 in the circumferential direction of the outer peripheral part of the flange 3 (refer to FIG. 6A). In addition, in this primary sealing process, the cover member 5 is heat-fused to the primary sealing area 31 by using a heat sealer (not shown in the figure), for example.

In this embodiment, the sterilization process is described using a short-time conditioning sterilization device RIC (hereinafter referred to as RIC) manufactured by Hiroka Seisakusho Co., Ltd. The short-time conditioning sterilization device RIC (not shown in the figure) here refers to a device having: a processing tank that can accommodate container-packaged food that becomes the processing object; a steam supply device that supplies steam to the processing tank; a decompression device that degases the processing tank to form a vacuum state; and a heating device that heats the processing tank.

In this embodiment, a degassing process is performed before the sterilization process to degas the storage part 2. During the degassing process, a plurality of packaging containers 1 containing food F on a tray and sealed with a lid member 5 at one time are arranged, and then the trays are stacked in a plurality of stages in the vertical direction and stored in a processing tank constituting RIC. After the lid of the processing tank is closed and the processing tank is sealed, the processing tank is degassed until it reaches a vacuum state. When the processing tank is degassed to a vacuum state, the air in the storage part 2 is also degassed through the flow path R, and the storage part 2 also becomes a vacuum state like the processing tank.

In the sterilization process, heated steam S is supplied to the processing tank and the temperature in the processing tank is set to, for example, 100°C to 145°C. The heated steam S supplied to the processing tank flows from the bottom of the flange 3 through the flow path R (through hole 38 and gap C) into the storage part 2. Thus, the food F contained in the storage part 2 is sterilized by the heated steam S.

In this embodiment, a cooling process is performed to cool the food F after the sterilization process. In the cooling process, the pressure in the aforementioned processing tank is reduced to discharge the heated steam S, and then the processing tank is made into a vacuum state, thereby evaporating the water and removing the latent heat from the food F, so that the food F is cooled.

Furthermore, after the cooling process, the lid of the aforementioned processing tank is opened and the packaging container 1 containing the food F is taken out together with the tray.

Then it is preferred to perform a gas replacement process. In the gas replacement process, an inert gas such as nitrogen or carbon dioxide is supplied to the container 2 through the flow path R.

The gas replacement process and secondary sealing process of this embodiment are performed when the packaging container 1 is placed on the mold of the heat sealer. The 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 this embodiment, the inert gas is supplied to any one of the four through holes 38 through the supply path of the mold. In addition, in the mold, an exhaust path for air exhaust is also formed at the positions 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 supply path.

As shown in FIG8A and FIG8B, after the gas replacement process, the secondary sealing process of sealing the cover member 5 and the secondary sealing area 32 is performed. Thus, the packaged food 6 consisting of the packaging container 1, the cover member 5 and the food F is obtained.

The secondary sealing process of this embodiment is a process of sealing the secondary sealing area 32 belonging to the outer peripheral portion of the flange portion 3 with the cover member 5 in a planar manner. In the secondary sealing process, the cover member 5 is heat-fused to the secondary sealing area 32 by using a heat sealer (not shown in the figure), for example.

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

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. As shown in FIG. 9 , the through hole 38 is closed and the uppermost portion 33 of the flange is also compressed to close the gap C. In the packaging container 1 of this embodiment, the through hole 38 in the packaging container 1 after secondary sealing is closed only by the cover member 5. However, when performing secondary sealing, the entire area of the flange portion 3 is pressurized from the top and bottom directions while the flange portion 3 is placed on a mold with a flat upper surface. In the packaging container 1 after secondary sealing, the through hole 38 can also be closed by the through area 36 deformed (pressed) by the cover member 5. In addition, when performing secondary sealing, the entire area of the flange portion 3 other than 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 while the uppermost portion 33 of the flange is not pressed and remains.

The above packaging container 1 can be preferably used as a packaging container 1 for packaging food 6, for example, after accommodating food F in the storage part 2 and providing a through hole 38 in the through area 36 of the flange part 3, the cover member 5 is sealed with the primary sealing area 31 of the flange part 3, and then the food F is sterilized by circulating heated steam S in the storage part 2 through the flow path R, and then the cover member 5 is sealed with the secondary sealing area 32 of the flange part 3.

In this packaging container 1, when a through hole 38 is provided at the inner side of 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 cover member 5 are sealed together, a gap C is generated between the flange lower portion 34 and the cover member 5, and the gap C constitutes a part of the flow path R. Therefore, when sterilizing the food F, the heated steam S flows from the bottom of the flange portion 3 through the flow path R constituted by the through hole 38 and the gap C into the container 2, thereby sterilizing the food F in the container 2.

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, when sterilizing the food F, the uppermost portion 33 of the flange maintains the gap C included in the flow path R. Therefore, the heated steam S can flow into the container 2 while the gap C is surely maintained in a state where it is not closed by the uppermost portion 33 of the flange.

Furthermore, in this packaging container 1, the cover member 5 is located above the flow path R, that is, the flow path R will not be exposed on the cover member 5, so it is not easy for fallen bacteria to be mixed into the packaging container 1 through the flow path R. In addition, since the secondary sealing area 32 is sealed with the cover member 5 to close the flow path R, the packaging container 1 can completely seal the food F through the secondary sealing of the cover member 5 and the container body 4.

In the packaging container 1 of this embodiment, when a through hole 38 is provided by forming a crack 380 in a part of the through area 36 (refer to FIG. 5 ), a part of the flange 3 will not be broken when the through hole 38 is formed, and no fragments of the flange 3 will be generated. Therefore, the fragments of the flange 3 can be prevented from mixing into the containing part 2.

In addition, in the packaging container 1 of this embodiment, since the through area 36 is a concave portion that is concave downward (refer to FIG. 2), the piercing needle pierces the concave through area 36 when forming the through hole 38, thereby keeping the pierced portion of the through area 36 in a state that is lower than other areas of the flange 3 (refer to FIG. 5), and it is not easy to return upward from the state that is located below. This prevents the through hole 38 from being closed, and maintains the through state of the through hole 38 until the secondary sealing area of the flange 3 and the cover member 5 are sealed.

Furthermore, in the packaging container 1 of this embodiment, since a through area 36 is arranged at a position across the container 2 (see FIG. 1A ), when a through hole 38 is provided at this position, the gas can flow from both sides of the container 2 through the through hole 38 (see FIG. 4A ), thereby suppressing uneven heating of the food F.

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 multi-layer 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. The aforementioned gas barrier layer can be considered an oxygen barrier layer.

The oxygen barrier layer is a layer that has the function of preventing gas penetration. For example, under the conditions of 20°C and 65%RH, the oxygen permeability measured according to JIS-K7126-2 (2006) Part 2 (isobaric method) is 100cc. 20μm/(m2.day.atm) or less, preferably 50cc. 20μm/(m2.day.atm) or less, and particularly preferably 10cc. 20μm/(m2.day.atm) or less. The oxygen permeability of "10cc.20μm/(m2.day.atm)" here means that in a 20μm barrier material (meaning the case consisting of an oxygen barrier layer alone), the oxygen permeability per day under 1 atmosphere of oxygen is 10cc.

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 polyvalent metal elements, processed starch, polyamide, polyester, polyvinylidene chloride, acrylonitrile copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl alcohol, inorganic layered compound, inorganic vapor deposition layer, metal foil and other gas barrier materials. In particular, from the perspective of having good oxygen barrier properties and melt formability, the oxygen barrier layer preferably contains EVOH, polyamide and processed starch or a combination thereof, and from the perspective of having particularly excellent melt formability, it is particularly preferred to contain EVOH.

(EVOH)

EVOH can be obtained, for example, by saponifying ethylene-vinyl ester copolymers. The production and saponification of ethylene-vinyl ester copolymers can be carried out by generally known methods. Vinyl esters that can be used in this method include: vinyl acetate, vinyl formate, vinyl propionate, trimethylacetic acid vinyl esters, and fatty acid vinyl esters such as vinyl versatate.

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 forming property and oxygen barrier property at high temperature tend to be improved. When the ethylene unit content is 60 mol% or less, the oxygen barrier property tends to be improved. The ethylene unit content in this EVOH can be measured, for example, by nuclear magnetic resonance (NMR: Nuclear Magnetic Resonance).

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%. 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. By making the saponification degree of EVOH within the above range, good oxygen barrier properties can be provided to the oxygen barrier layer constituting the container body 4 or the cover member 5.

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

Such other monomers that EVOH may have include, for example, propylene, butene, pentene, hexene, etc.; 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-hexene Ester-containing olefins such as 1,2-dimethoxy-1-hexene, 6-acyloxy-1-hexene, 5,6-diacyloxy-1-hexene, 1,3-diethoxy-2-methylenepropane, or their saponified products; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or their anhydrides, salts, or mono- or di-alkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, methylallyl sulfonic acid, or their salts; vinyl silane compounds such as vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(β-methoxy-ethoxy) silane, γ-methacryloxypropyl trimethoxysilane, or the like; alkyl vinyl ethers, vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinylidene chloride, etc.

EVOH can be EVOH modified by urethanization, acetalization, cyanoethylation, oxyalkylation, etc. Such modified EVOH tends to improve the melt formability of the above-mentioned oxygen barrier layer.

EVOH can also be used in combination of two or more types of EVOH with different ethylene unit content, saponification degree, copolymer components, presence or absence of modification or type of modification, etc.

EVOH can be obtained by generally known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In one embodiment, a bulk polymerization method or a solution polymerization method that can be performed in a solvent-free solution or in an alcohol solution is used.

The solvent used in the solution polymerization method is not particularly limited, for example, alcohol, preferably methanol, ethanol, propanol and other lower alcohols. The amount of solvent in the polymerization reaction solution can be selected by considering the viscosity average polymerization degree of the target EVOH or the chain transfer of the solvent. The mass ratio of the solvent to the total monomer amount (solvent/total monomer) contained in the reaction solution is, for example, 0.01 to 10, preferably 0.05 to 3.

In addition, the catalyst used in the above polymerization can be listed as follows: azo initiators such as 2,2-azobisisobutyronitrile, 2,2-azobis-(2,4-dimethylvaleronitrile), 2,2-azobis-(4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis-(2-cyclopropylpropionitrile); organic peroxide initiators such as isobutylene peroxide, isopropyl peroxyneodecanoate, diisopropyl peroxycarbonate, di-n-propyl peroxydicarbonate, tertiary butyl peroxyneodecanoate, lauryl peroxide, benzoyl peroxide, tertiary butyl hydroperoxide, etc.

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

In the above polymerization, after a predetermined polymerization time or after reaching a predetermined polymerization rate, a polymerization inhibitor may be added as needed to evaporate and remove unreacted ethylene gas, thereby removing unreacted vinyl ester.

Then, an alkaline catalyst is added to the copolymer solution to saponify the copolymer. Both continuous and batch methods can be used as saponification methods. Examples of alkaline catalysts that can be added include sodium hydroxide, potassium hydroxide, alkali metal alcoholates, etc.

EVOH after saponification contains alkaline catalysts, derivative salts such as sodium acetate or potassium acetate, and other impurities. Therefore, it is better to neutralize or wash as needed to remove the catalysts, salts, and impurities. Here, when washing EVOH after saponification with water (such as ion exchange water) that contains almost no predetermined ions (such as metal ions and chloride ions), it is also possible to not completely remove the derivative salts such as sodium acetate or potassium acetate and leave some of them.

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 ingredients. From the perspective of the thermal stability of the oxygen barrier layer or good adhesion with other resins, it is better to contain metal salts and acids.

From the viewpoint of improving the indirectness of the layer, the above-mentioned metal salt is preferably an alkaline metal salt, and from the viewpoint of improving the thermal stability, it is preferably an alkaline earth metal salt. When EVOH contains a metal salt, the content thereof is, for example, 1 ppm or more, 5 ppm or more, 10 ppm or more, or 20 ppm or more, calculated as the metal atom of the metal salt relative to EVOH. In addition, when EVOH contains a metal salt, the content thereof is, for example, 10000 ppm or less, 5000 ppm or less, 1000 ppm or less, or 500 ppm or less, calculated as the metal atom of the metal salt relative to EVOH. By making the content of the metal salt within the range formed by the above lower limit and upper limit, the interlayer adhesion of the above oxygen barrier layer is well maintained, and the thermal stability of EVOH when the container body 4 is recycled is well maintained.

Examples of the above-mentioned acid include carboxylic acid compounds and phosphoric acid compounds. These acids are useful from the viewpoint of improving the thermal stability of EVOH when it is melt-formed. In the case where EVOH contains a carboxylic acid compound, the content of the carboxylic acid (that is, the content of the 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, less than 10000 ppm, less than 1000 ppm, or less than 500 ppm. In the case where EVOH contains a phosphoric acid compound, the content of phosphoric acid (that is, the phosphate-converted content of the phosphoric acid compound in the oxygen barrier layer containing EVOH) is, for example, 1 ppm or more, 10 ppm or more, or 30 ppm or more. In addition, the content of the phosphoric acid compound is, for example, less than 10000 ppm, less than 1000 ppm, or less than 300 ppm. By making EVOH contain a carboxylic acid compound or a phosphoric acid compound within the above range, the thermal stability of EVOH during melt molding tends to be improved.

When EVOH contains the above-mentioned boron compound, the content (i.e., the boron-converted content of the boron compound 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 boron compound is, for example, less than 2000 ppm, less than 1000 ppm, or less than 500 ppm. By making EVOH contain a boron 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.

There is no particular limitation on the method for making the oxygen barrier layer containing EVOH contain the above-mentioned carboxylic acid compound, phosphoric acid compound or boron compound. For example, the above-mentioned compounds can be added and kneaded when the composition containing EVOH is granulated. There is no particular limitation on the method for adding the above-mentioned carboxylic acid compound, phosphoric acid compound or boron compound. Examples include: a method of adding in the form of dry powder, a method of adding in a paste state impregnated with a predetermined solvent, a method of adding in a state suspended in a predetermined liquid, a method of adding as a solution by dissolving in a predetermined solvent, a method of immersing in a predetermined solution, etc. In particular, from the reason that the above-mentioned compounds can be uniformly dispersed in EVOH, the method of adding as a solution by dissolving in a predetermined solvent and the method of immersing in a predetermined solution are preferably adopted. The solvent used in this method is not particularly limited. Considering the solubility, cost, ease of handling, safety of the working environment, etc. of the compounds added as additives, water is preferred.

When the oxygen barrier layer in the multilayer structure contains EVOH as the 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 means the component with the largest mass% among the components constituting the oxygen barrier layer.

In the case where the oxygen barrier layer in the multilayer structure contains EVOH as the 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 means the value obtained by dividing the total thickness of the above-mentioned oxygen barrier layer containing EVOH as the 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, softness, 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.

(Complex structure containing phosphorus and polyvalent metal elements)

The composite structure containing phosphorus and a polyvalent metal element has a barrier layer formed by reacting a phosphorus compound with a polyvalent metal compound. The 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. When M is used to represent the polyvalent metal atom, a bond represented by M-O-P is formed between the polyvalent metal atom M and the phosphorus atom. The characteristic absorption band of the M-O-P bond in the infrared absorption spectrum can be observed in the region of 1080cm-1 to 1130cm-1. 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.

The substrate on 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 particularly preferred. The form of the substrate is not particularly limited, and may be a layer such as a film or sheet. The substrate is particularly preferably composed of a thermoplastic resin film and paper, and more preferably a thermoplastic resin film. The thermoplastic resin film is preferably polyester, and polyethylene terephthalate is particularly preferred because it can impart good mechanical strength to the composite structure.

The polyvalent metal element is not particularly limited as long as it is a polyvalent metal element that can react with more than two molecules of phosphorus compounds, 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.

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 as the polyvalent metal compound can be used.

Furthermore, microparticles of a polyvalent metal compound may be dispersed in water or an aqueous solvent and used as a dispersion. This dispersion is preferably a dispersion of aluminum oxide microparticles. In general, microparticles of a polyvalent metal oxide have hydroxyl groups on the surface, 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 triethoxide, 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 polyvalent metal oxide particles preferably have a spherical, flat, polyhedral, fibrous or needle-shaped shape. From the reason that the oxygen barrier property can be improved, the fibrous or needle-shaped shape is preferred. Furthermore, in order to improve the oxygen barrier property and transparency, the average particle size of the polyvalent metal oxide particles is preferably greater than 1nm and less than 100nm.

The phosphorus compound is not particularly limited as long as it can react with a polyvalent metal compound to form the above-mentioned bond, and any phosphorus compound can be used. Examples of phosphorus compounds include phosphoric acid compounds and their derivatives. Specific examples include: phosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid. Examples of the above-mentioned polyphosphoric acid include: polyphosphoric acid formed by condensation of pyrophosphoric acid, triphosphoric acid, or 4 or more phosphoric acids. In addition, derivatives of phosphoric acid compounds include: phosphates, esters (such as trimethyl phosphate), halides, and dehydrates (such as phosphorus pentoxide).

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

The coating agent can be obtained by mixing a solution or dispersion of a polyvalent metal compound and a solution of a phosphorus compound. Other components may be added to the above coating agent. Examples of other components include: polymer compounds, metal complexes, 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 meth)acrylate, polysaccharides (such as starch), acrylic polymers (such as polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymers) and salts thereof, 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.

For example, the coating film obtained by applying the coating agent and drying and removing the solvent is subjected to heat treatment, so that the polyvalent metal compound and the phosphorus compound react to form the above-mentioned bond, and a composite structure containing phosphorus and polyvalent metal elements can be formed. The temperature used for the heat treatment is preferably above 110°C, more preferably above 120°C, more preferably above 140°C, and particularly preferably above 170°C. In the case where the temperature used for the heat treatment is lower, it takes more time to form a sufficient bond, which sometimes reduces productivity. 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. Such heat treatment can be performed in any environment of atmospheric environment, nitrogen environment, or argon environment.

The lower limit of the average thickness of a single layer of an oxygen barrier layer including 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 lower limit of the average thickness of a single layer of an oxygen barrier layer including 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 including a composite structure containing phosphorus and a polyvalent metal element as a main component" used in this specification means the value obtained by dividing the total thickness of all oxygen barrier layers 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 the single layer of the oxygen barrier layer is less than the above lower limit, it is difficult to form a layer of uniform thickness, which may reduce the durability of the obtained multilayer structure. When the average thickness of the single layer of the oxygen barrier layer is higher than the above upper limit, the flexibility, stretchability, thermal properties, etc. of the obtained multilayer structure may be reduced.

(Processed starch)

The starch used as the raw material for processing starch is not particularly limited, and examples thereof include starch from wheat, corn, cassava, potato, rice, oats, arrowroot starch and peas. The starch is preferably high-amylose starch, and particularly preferably high-amylose corn starch and high-amylose cassava starch.

The processed starch is preferably a starch chemically modified in which the hydroxyl group is substituted by a functional group of ether, ester or a combination thereof. The processed starch is preferably a starch modified in which a hydroxyl group having 2 to 6 carbon atoms is contained, or the processed starch is modified by reacting with a carboxylic anhydride. In the case where the processed starch is a starch modified in which a hydroxyl group having 2 to 6 carbon atoms is contained, it is preferred that the processed starch has a functional group having 2 to 4 carbon atoms as a substituent, for example, it is preferred that the processed starch has a hydroxyethyl group or a hydroxybutyl group which can generate a hydroxyether substituent. Furthermore, in the case where the processed starch is a starch modified by reacting with a carboxylic anhydride, the functional group is preferably a butyrate or a lower homologue, and more preferably an acetate. To make ester derivatives, dicarboxylic anhydrides such as maleic acid, phthalic acid or octenylsuccinic anhydride can also be used.

The processed starch is preferably a hydroxypropylated straight chain starch containing hydroxypropyl groups, and is particularly preferably a hydroxypropylated high straight chain starch.

The degree of substitution of processed starch is expressed as the average number of substituents per unit of anhydrous glucose, and the maximum value is usually 3. The degree of substitution of the above-mentioned processed starch is preferably above 0.05 and below 1.5.

Processed starch may also contain other starches. Other starches include, for example, a mixture of high-amyl starch and low-amyl starch.

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

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 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 one or more water-soluble polymers is, for example, 1% by mass or more or 4% by mass or more.

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

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

The average thickness of a single layer of the oxygen barrier layer containing processed starch as a main component is, for example, greater than 10 μm or greater than 100 μm. The average thickness of a single layer of the oxygen barrier layer containing processed starch as a main component is, for example, less than 1000 μm or less than 800 μm. The term "average thickness of a single layer of the oxygen barrier layer containing processed starch as a main component" used in this specification means the value obtained by dividing the total thickness of all the oxygen barrier layers containing processed starch 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 oxygen barrier layer is less than the above lower limit, it is difficult to form a layer of uniform thickness, and the durability of the obtained multilayer structure is sometimes reduced. When the average thickness of the single layer of the oxygen barrier layer is higher than the upper limit, the flexibility, stretchability, thermal conductivity, etc. of the obtained multi-layer structure may be reduced.

(Inorganic layered compounds)

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 in the barrier layer containing an inorganic layered compound is not particularly limited, and examples thereof include polyamide, ethylene-vinyl alcohol copolymer, etc.

Inorganic layered compounds include: swelling mica, clay, montmorillonite, smectite, hydrotalcite, etc. In addition, inorganic layered compounds can also be organically modified inorganic layered compounds that have been organically treated.

The inorganic layered compound is composed of plate-like crystals, for example, and has any appearance such as circular, non-circular, elliptical, roughly oblong, roughly spherical, etc. The average length of the long side of the plate-like crystals of the inorganic layered compound that can be measured by an electron microscope preferably satisfies a predetermined range.

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

In addition, the inorganic layered compound preferably does not contain coarse matter with a thickness exceeding 2 μm. In the case where the inorganic layered compound contains coarse matter with a thickness exceeding 2 μm, transparency or stretchability may sometimes be reduced.

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

(Inorganic vapor deposition layer)

The inorganic vapor-deposited layer is a barrier layer obtained by, for example, vapor-depositing an inorganic substance onto a substrate. Examples of substrates that can constitute the inorganic vapor-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 particularly preferred are thermoplastic resins. When the substrate is composed of the above-mentioned resins, the form is preferably a layered form such as a film or a sheet.

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, nylon-12; hydroxyl-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers; polystyrene; poly(meth)acrylate; polyacrylonitrile; polyvinyl acetate; polycarbonate; polyacrylate; regenerated cellulose; polyimide; polyetherimide; polysulfone; polyethersulfone; polyetheretherketone; ionomer resins, etc. Preferably, it is at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, nylon-6 and nylon-66.

When a film made of a thermoplastic resin is used as a substrate, the substrate may be either a stretched film or a non-stretched film. From the perspective of the superior processing suitability (printing, lamination, etc.) of the obtained multi-layer structure, a stretched film is preferred, and a biaxially stretched film is particularly preferred. The biaxially stretched film may be a biaxially stretched film produced by any of the synchronous biaxial stretching method, the sequential biaxial stretching method, and the tubular stretching method.

Examples of paper that can be used as a substrate include: kraft paper, woodfree paper, molded paper, glass paper, parchment paper, synthetic paper, whiteboard paper, gray-backed whiteboard paper, milk carton paper, paper cup paper, ivory paper, etc.

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, in view of the mechanical strength and processability of the obtained multi-layer structure.

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; and metal carbonitrides such as silicon carbonitride. In terms 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 of these, is preferred.

The method for forming the inorganic deposition layer is not particularly limited. For example, physical vapor growth methods such as vacuum deposition (such as resistive heating deposition, electron beam deposition, molecular beam epitaxy, etc.), ion plating, sputtering (double magnetron sputtering, etc.) and the like; chemical vapor growth methods such as thermochemical vapor growth (such as catalytic chemical vapor growth), photochemical vapor growth, plasma chemical vapor growth (such as capacitive coupled plasma, inductively coupled plasma, surface wave plasma, electron gyrotron resonance plasma, etc.), atomic layer deposition, and organic metal vapor growth.

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 even more preferably 0.01μm to 0.1μm. Within this range, a thickness that provides good barrier properties and mechanical properties of the multi-layer structure 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 relative to oxygen and water vapor tends to decrease, and there may be a situation where the inorganic vapor-deposited layer does not exhibit 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 reduced when the multi-layer structure is stretched or bent.

(Metal foil)

Metal foil is a single-layer or multi-layer structure composed of a metal with excellent ductility. Examples of metals contained in metal foil include aluminum. The metal foil has the form of aluminum foil or aluminum strip, for example.

According to the packaging container with the oxygen barrier layer, the intrusion of oxygen can be prevented and the quality of the sterilized contents can be maintained for a longer period of time.

The packaging container of the present invention is not limited to the above-mentioned embodiments, 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 part of the structure of a certain embodiment can be replaced by the structure of other embodiments. Furthermore, part of the structure of a certain embodiment can also be deleted.

The flange uppermost portions 33A and 33B of 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 are not limited thereto. As shown in FIG. 10 and FIG. 11 , it is also conceivable to provide the flange portion 3 with a third flange uppermost portion 33C having a height substantially equal to the outer diameter when viewed from above. The third flange uppermost portion 33C is circular when viewed from above.

The through hole 38 of the above-mentioned embodiment is formed by piercing the through area 36 of the flange 3 with a piercing needle (that is, breaking the through area 36), but it is not limited to this. For example, it can be considered that the through hole 38 is formed by punching the through area 36 of the flange 3.

As shown in FIG. 12A and FIG. 12B, when the through hole 38 is formed by punching the through area 36 of the flange 3 in the through hole forming process, the through area 36 is removed from the flange 3. In this structure, the flow of gas to the through hole 38 will not be hindered by the through area 36 from the through hole forming process to the sealing of the secondary sealing area 32, so the heated steam S can flow smoothly in the through hole 38.

In the packaging container 1 of the above-mentioned embodiment, the flange uppermost portion 33 is located on the inner side of the through-region 36, and the primary sealing region 31 is located on the outer side of 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 be used as the primary sealing region 31. Since the primary sealing region 31 must be located further outside the through-region 36, at least one of the plurality of flange uppermost portions 33 in this configuration is located on the outer side of the through-region 36. For example, it can be considered that the flange uppermost portion 33 has a fourth flange uppermost portion 33D, which is located on the outer side of the through-region 36 and also serves as the primary sealing region 31.

The flange uppermost portion 33 may also be the fourth flange uppermost portion 33D of the convex strip. In addition, in the flange uppermost portion 33, the 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 (refer to FIG. 12B). In the case where the flange uppermost portion 33 is a convex strip, for example, it may be continuously provided in the circumferential direction of the opening edge 21. Specifically, the flange uppermost portion 33 may be considered to be a convex strip continuously provided in the circumferential direction of the opening edge 21 over the entire circumference.

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 can also be provided in a part of the flange portion 3. In the configuration in which the uppermost portion 33 of the flange also serves as the primary sealing area 31 (refer to FIG. 12A and FIG. 12B), as shown in FIG. 13A and FIG. 13B showing the state after the secondary sealing process, it can be considered that the area located further inward than the primary sealing area 31 in the flange lower portion 34 also serves as the secondary sealing area 32.

Furthermore, in the packaging container 1 of the above-mentioned embodiment, the secondary sealing process is performed by surface sealing, but it can also be performed by continuous line sealing around the entire circumference of the opening edge 21. For example, as shown in Figures 14A and 14B, line sealing can be performed. In this case, the secondary sealing area 32 can be considered to be a convex strip protruding upward.

In addition, in this case, the upper surface of the secondary sealing area 32 is located below the upper surface 330 of the uppermost portion of the flange (also serving as the upper surface of the fourth uppermost portion 33D of the primary sealing area 31). Furthermore, when the cover member 5 and the primary sealing area 31 are sealed, the flange portion 3 is configured to form a gap C between the upper surface of the secondary sealing area 32 and the lower surface of the cover member 5. Thus, from the time when the primary sealing process is performed to the time when the secondary sealing process is performed, that is, when the food F is sterilized, a gap C is generated between the lid member 5 supported by the upper surface 330 of the uppermost portion of the flange and the upper surface 340 of the lower portion of the flange, and the first flange upper surface 230 maintains the gap C and securely maintains the gap C in an unsealed state, thereby allowing the heated steam S to flow through the flow path R into the container 2.

In the above-mentioned embodiment, a convex portion such as the uppermost portion 33 of the flange is provided on the flange portion 3, but a concave portion recessed downward may also be provided, or as shown in FIG. 15A and FIG. 15B, a groove portion 39 is provided on the flange portion 3 as the flange lower portion 34. For example, it can be considered that the groove portion 39 is continuous in the circumferential direction along the opening edge 21. Specifically, the groove portion 39 is continuous in the circumferential direction of the opening edge 21 over the entire circumference.

In the structure in which the recess is provided in the flange 3, a through area 36 can be provided in the recess. For example, it can be considered that the through area 36 is provided in the groove 39 of the flange 3. Specifically, it can be considered that in the groove 39 which is continuous in the circumferential direction of the opening edge 21, a through area 36 is provided on a pair of sides opposite to each other across the accommodating portion 2. In this case, the through areas 36 provided on each side are arranged, for example, at opposite positions across the accommodating portion 2. In this structure, when the through hole forming process is performed, a through hole 38 is provided in the groove 39 of the flange 3.

In addition, in this case, it can be considered that the primary sealing area 31 is continuously provided on the outer side of the groove portion 39 of the flange portion 3 (the uppermost portion 33 of the flange) in the circumferential direction of the opening edge 21. Specifically, it can be considered that the primary sealing area 31 is continuous in the entire circumference of the opening edge 21.

In the above-mentioned structure in which the through area 36 is provided in the groove 39 of the flange 3 (refer to Figures 15A and 15B), as shown in Figures 16A and 16B, it can be considered that the secondary sealing area 32 is continuously provided on the inner side of the groove 39 of the flange 3 along the opening edge 21 in the circumferential direction. Specifically, it can be considered that the secondary sealing area 32 is continuous in the entire circumference of the opening edge 21. In the flange 3 of the above-mentioned structure, the groove 39 with 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 39.

In addition, the through area 36 may be provided only at a corner of a part of the multiple corners of the flange 3. For example, as shown in FIG17A, the through area 36 may be provided only at a pair of corners of the flange 3 across the accommodating portion 2. In this case, as shown in FIG17B, the through hole 38 is provided only at a pair of corners of the flange 3 across the accommodating portion 2.

Furthermore, the flange top portion 33 may also be the fifth flange top portion 33E of a hemispherical hillock-shaped convex portion. The flange top portion 33 may also be in other shapes such as a cone, a cone-like ladder, a cylinder, a polygonal cylinder, or a polygonal hammer.

The bottom plate 22 of the storage portion 2 of the above-mentioned embodiment is roughly rectangular, but it can also be roughly square. In addition to the quadrangular plate, the bottom plate 22 can also be other polygonal plates or circular plates.

In the packaging container 1 of the above-mentioned embodiment, a through area 36 is provided on the flange 3 and a through hole 38 is provided on the flange 3 by performing a through hole forming process, but the through area 36 may not be provided on the flange 3. This structure can be considered in the structures of Figures 18 to 21, etc.

For example, as shown in FIG. 18A and FIG. 18B , it is considered that the flange portion 3 has a primary sealing area 31 sealed with the cover member 5 in a primary sealing process, and is configured such that when the cover member 5 and the primary sealing area 31 are sealed, a flow path R is formed between the cover member 5 and the cover member 5 for gas to flow between the outside and the inside of the container 2. In this configuration, the uppermost portion 33 of the flange is a convex strip extending in a circumferential direction of the opening edge 21 at intervals on 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. Furthermore, as shown in FIG. 19A and FIG. 19B , the portion of the flange lower portion 34 that is continuously provided in the entire circumference of the opening edge 21 also serves as the secondary sealing area 32.

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 top of the flange upper surface 30, and the upper surface of the secondary sealing area 32 (e.g., the portion of the flange lower upper surface 340 that is continuously arranged around 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 such 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 is configured to become a part of the flow path R.

In the packaging container 1 of the above-mentioned embodiment, the primary sealing process is performed by line sealing, but it can also be performed by point sealing of at least one point. For example, as shown in Figures 20A and 20B, it can be considered that a plurality of protrusions are provided 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 can be considered 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 arranged with gaps in the circumferential direction of the opening edge 21, after the primary sealing process is performed, the heated steam S flows into the storage part 2 through the gaps between the primary sealing areas 31 in the circumferential direction, so that a sufficient amount of heated steam S can flow into the storage part 2.

For example, as shown in FIG. 21A and FIG. 21B, a plurality of recesses may be provided on 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, for example, the four corners of the flange portion 3. In this case, the flange uppermost portion 33 is located on each side of the flange portion 3. In this configuration, the flange uppermost portion 33 also serves as the primary sealing area 31. In addition, in this configuration, after the primary sealing process, a gap C is generated between the lower surface of the cover member 5 and the upper surface 340 of the flange lower portion. This gap C is located at the four corners of the flange portion 3, so the heated steam S flows from the four corners of the flange portion 3 into the accommodating portion 2.

In the packaging container 1 of the above-mentioned embodiment, the shapes or sizes of the through holes 38 formed in the flange 3 are the same, but they may be different. For example, as shown in FIG. 22A and FIG. 22B, it is considered that a through hole 38A is provided at one of the four corners of the flange 3 that is adjacent to each other, and a through hole 38B of a different size from the through hole 38A is provided at one of the four corners of the flange 3 that is other than the aforementioned adjacent one of the corners. The diameter of the through hole 38A is larger than the diameter of the through hole 38B.

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

In this way, on the inner side of the primary sealing area 31, since the uppermost portion of the flange 33 is provided at both the outer side and the inner side of the through hole 38A, the uppermost surface 330 of the flange supports the cover member 5 at the outer side and the inner side of the through hole 38A, thereby maintaining a state in which a gap C is generated between the through hole 38A and the cover member 5, thereby preventing the through hole 38A from being closed.

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

Furthermore, after the secondary sealing process is performed, a portion of the flange portion 3 including the through hole 38 may be removed. For example, in the above-mentioned structure in which the through holes 38 are provided at the four corners of the flange portion 3 (refer to FIG. 22A and FIG. 22B ), as shown in FIG. 23A and FIG. 23B , it may be considered 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 is performed, the flange portion 3 is cut off 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 in the flange 3 are easily retained around the through hole 38. However, by removing a portion of the flange 3 including the through hole 38, the water droplets can be prevented from affecting the packaging container 1.

In FIG. 23 , the cut line L is set by cutting off the four corners of the flange 3, but it can also be set by extending between the through hole 38 and the secondary sealing area 32 and continuously cutting off the entire circumference of the opening edge 21. That is, the cut line L can also be set by cutting off the outer periphery of the through hole 38 including the flange 3.

The through area 36 of the above-mentioned 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-mentioned embodiment is formed by forming a crack 380 on the through area 36 provided with the cross-shaped groove 360 or punching the through area, but it may also be formed by other methods.

In addition, as shown in FIG. 24A and FIG. 24B , it is conceivable to form a U-shaped crack 380 in a plan view on the flange portion 3 to form each through hole 38. In this configuration, the flange portion 3 has an eighth flange uppermost portion 33H, which is formed by deforming a portion of the flange portion 3 (e.g., the through-region 36) upward with the crack 380 as a boundary, and the upper surface is located at the uppermost portion of the upper surface 30 of the flange portion 3. In addition, a flow path R is formed between the cover member 5 and the flange portion 3 by the eighth flange uppermost portion 33H. Specifically, a U-shaped crack 380 is formed in the through-hole area 36, and a straight line 381 connecting the base ends of the crack 380 is used as a boundary, so that the inner side of the U-shaped crack 380 is bent upwards compared to other areas of the flange portion 3 to form a through hole 38, and the eighth flange uppermost portion 33H is formed. In addition, a second flange uppermost portion 33B can be provided near the through hole 38.

In addition, as shown in FIG. 25A and FIG. 25B, 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 bounded by a pair of straight lines 381 extending from both ends of the crack 380, and the area outside the through area 36 of the flange portion 3 is lifted upward to form the through hole 38, and the eighth flange uppermost portion 33H is formed.

In this way, in the structure in which the through hole 38 is formed by deforming the through area 36 upwardly from the through area 36 of the flange 3, when the heated steam S flows from the bottom of the flange 3 to the accommodating portion 2, the through area 36 is easily kept lifted by the heated steam S, so the through hole 38 is easily maintained in an open state.

In addition, as shown in FIG. 26A and FIG. 26B, in the structure in which the through hole 38 is formed by positioning the through area 36 above the area other than the through area 36 of the flange portion 3 and the eighth flange uppermost portion 33H is formed, the third flange uppermost portion 33C may be provided near the through hole 38.

Furthermore, as shown in FIG. 27A and FIG. 27B, when deforming the through area 36 upward, it is preferable to use an auxiliary tool to form a depression from the top at the junction 382 between the flange 3 and the through area 36, and use the depression as a starting point to deform the through area 36 upward. In this case, the junction 382 of the flange 3 becomes easy to bend, and it is easy to keep the through area 36 lifted.

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 the boundary, and the flow path R is formed by the eighth flange uppermost portion 33H, so that the heated steam S can flow into the accommodating portion 2 through this flow path R.

Furthermore, as shown in FIG. 28A and FIG. 28B, 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 can be provided on the flange portion 3 as the flange uppermost portion 33. According to this structure, in addition to the eighth flange uppermost portion 33H in the flange portion 3, even if the flange uppermost portion 33 is not formed separately, it is only necessary to form a crack 380 in the flange portion 3 to form a through hole 38, so as to form a flow path R for the heated steam S to flow.

When forming the through hole 38, the through area 36 will become the uppermost part 33H of the eighth flange. For example, the through hole 38 can be formed by the following process. First, as shown in FIG. 29A, positioning is performed to form the crack 380 on the flange part 3. As shown in FIG. 29B, the crack 380 is formed by an auxiliary tool for cutting. Furthermore, as shown in FIG. 29C, an auxiliary tool for forming a depression is knocked into the boundary 382 of the through area 36. As shown in FIG. 29D, the through area 36 is deformed upward by the impact to form the through hole 38.

As shown in FIG. 30A and FIG. 30B , the through-region 36 is a convex portion protruding upward, and the upper end of the convex portion can constitute the eighth flange uppermost portion 33H. In addition, the through-region 36 can be considered to have a curved surface that bulges 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 this 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. On the outer periphery of the through-region 36 of this embodiment, the arc-shaped portion is arranged more inward than the straight line portion. In addition, in this configuration, by forming a crack 380 at a portion of the outer periphery of the through-region 36 (e.g., an arc-shaped portion) and deforming the through-region 36 upward, as shown in FIG. 30C , the through-region 36 becomes a convex curved surface facing upward.

In the case where the through region 36 is a convex portion protruding upward, the entire area of the upper surface of the convex portion may be an inclined surface that is not curved, or only a portion of the upper surface of the convex portion may be a curved surface. For example, as shown in FIG. 31A and FIG. 31B , the through region 36 may be a convex portion of a curved surface whose upper portion of the upper surface bulges upward, and the upper end of the curved surface constitutes the eighth flange uppermost portion 33H. 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 rectangular shape with rounded corners. In addition, in this configuration, by forming a crack 380 in a portion of the outer periphery of the through-region 36 (for example, excluding a portion located on one side of the outer side in the outer periphery, that is, three sides and a pair of corners in the rectangular outer periphery) and deforming the through-region 36 upward, as shown in FIG. 31C, the through-region 36 becomes a curved surface that bulges upward.

In this way, in the configuration in which a portion of the flange portion 3 deformed upward (e.g., the through area 36) is a curved surface that bulges upward, when the primary sealing area 31 and the cover member 5 are sealed, by forming a crack 380 in the flange portion 3, the convex curved surface that bends upward can stably support the cover member 5 without causing damage to the cover member 5.

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

In the packaging container 1 of the above-mentioned embodiment, the through hole 38 is arranged at the corner of the flange 3, but as shown in FIG. 32A, the through hole 38 may also be arranged in the area other than the corner of the flange 3. In addition, the packaging container 1 of the above-mentioned embodiment has one storage part 2, but as shown in FIG. 32B to FIG. 32C, it may also have a plurality of storage parts 2. In this case, it may be considered that the through hole 38 is arranged between adjacent storage parts 2 (in the area sandwiched by the storage parts 2).

In the packaging container 1 of the above-mentioned embodiment, a through area 36 is provided on the flange 3, but a through hole 38 may be provided in advance on the flange 3 to replace the through area 36. In this case, the manufacturing method of the packaged food 6 does not include a through hole forming process, but becomes a method including a food containing process, a primary sealing process, a sterilization process and a secondary sealing process.

In the method for manufacturing packaged food of the above-mentioned embodiment, the food containing process, the through hole forming process, the primary sealing process, the sterilization process and the secondary sealing process are sequentially performed. However, the food containing process can also be performed after the through hole forming process. In addition, the packaging container 1 can also be preferably used as a packaging container 1 for packaging food 6, wherein after the through hole 38 is set in the through area 36 of the flange 3 and the food F is contained in the containing part 2, the cover member 5 is sealed with the primary sealing area 31 of the flange 3, and then the heated steam S is circulated in the containing part 2 through the flow path R to sterilize the food F, and then the cover member 5 is sealed with the secondary sealing area 32 of the flange 3.

The flange portion 3 of the above-mentioned embodiment is arranged on the entire circumference of the opening edge 21, but it can also be arranged in an interrupted state (with intervals) in this circumferential direction.

In the packaging container 1 of the above-mentioned embodiment, the container 2 and the flange 3 are formed by a single component, but they can also be formed by different components. For example, it can be considered that the container body 4 is formed by different components to form the container 2 and the flange 3, and the container 2 or the flange 3 is connected by a bonding agent, so that the container 2 and the flange 3 are connected to form a structure.

In addition, in the present invention, various contents can be contained as sterilization objects. The contents are, for example, items that do not want to come into contact with pollutants such as bacteria, dust, or oxygen during storage or transportation, including food, cosmetics, pharmaceuticals, quasi-pharmaceuticals, medical equipment, sanitary products, physical and chemical products, and biological related products. Food is preferred, and food that can maintain its appearance and quality during steam sterilization at high temperature and high pressure is particularly preferred (for example, solid food when contained).

In addition, the sterilizing gas used in the present invention is heated steam in the above-mentioned embodiment, but other sterilizing gases such as ozone gas, ethylene oxide, formaldehyde, acetic acid, ethylene oxide, chlorine dioxide, etc. can also be used according to the contents.

From the above content, according to the present invention, a packaging container can be provided that can be preferably used when sterilizing the contents and can maintain the quality of the sterilized contents for a long period of time.

The packaging container of the present invention is a packaging container for sterilization treatment, which exposes the contents contained therein to a sterilizing gas for sterilization, and then seals the contents and allows them to circulate. The packaging container has a container body, which includes: a storage portion having an opening at the top and storing the contents, and a flange portion extending outward from the opening edge of the storage portion; the flange portion includes: a primary sealing area that is sealed with a cover member covering the opening in a primary sealing process, and a secondary sealing area that is secondary sealed with the cover member in a secondary sealing process after the primary sealing, and the upper surface of the flange portion is located at the bottom of the flange portion. The flange uppermost portion is the uppermost portion of the upper surface of the flange, the flange lower portion whose upper surface is located below the upper surface of the flange uppermost portion, and at least one through-hole located inside the primary sealing region and penetrating the flange portion; and the flange portion is configured such that after 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 accommodating 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 region are sealed, the flow path is closed.

The packaging container of this structure is suitable as a container used, for example, when the contents are contained in the storage part and a through hole is provided in the through area of the flange, or when a through hole is provided in the through area of the flange and food is contained in the storage part, the lid member is sealed with the primary sealing area of the flange, and then the contents are sterilized by passing a sterilizing gas through the flow path in the storage part, and then the lid member is sealed with the secondary sealing area of the flange.

In this packaging container, when a through hole is provided inside the primary sealing area of the flange, the through hole constitutes a part of the flow path. In addition, when the primary sealing area and the lid member are sealed, a gap is generated between the lower part of the flange of the flange and the lid 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 through the flow path formed by the through hole and the gap into the storage part, thereby sterilizing the contents in the storage part.

In particular, in a packaging container, since the upper surface of the uppermost portion of the flange is located above the upper surface of the lower portion of the flange, when the contents are sterilized, the uppermost portion of the flange supports the lid member, so that the sterilizing gas can flow into the container while the gap constituting the flow path is surely maintained by the uppermost portion of the flange and is not closed.

Furthermore, in this 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 sterilizing gas, it is not easy for fallen bacteria to be mixed into the container through the flow path. In addition, since the flow path is sealed by the secondary sealing area and the cover member, the packaging container can completely seal the contents by sealing with the cover member.

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

According to this structure, when forming a through hole in the through area, a part of the flange portion will not be broken, and no fragments of the flange portion will be generated. Therefore, it is possible to prevent the fragments of the flange portion from mixing into the accommodating portion.

The aforementioned through area may also have a curved surface that bulges upward, and the upper end of the aforementioned curved surface may also constitute the uppermost portion of the aforementioned flange.

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

In addition, in the aforementioned packaging container, the aforementioned through area may also be a concave portion that is concave downward, and the aforementioned crack may also be formed in the concave portion.

According to this structure, when forming a through hole, the through area that is recessed downward is perforated from the top, so that the perforated portion of the through area is easily maintained in a state that is lower than other areas of the flange portion, thereby preventing the through hole from being closed by this portion.

In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided on the entire circumference of the opening edge of the aforementioned storage portion, and the aforementioned through-area may also be provided in plural numbers and arranged at opposite positions across the aforementioned storage portion.

According to this structure, since a through area is arranged at a position opposite to the storage part, when a through hole is set at this position, the gas can flow from both sides of the storage part through the through hole, thereby suppressing uneven heating of the food.

Another packaging container of the present invention is a packaging container for exposing the contents contained therein to a sterilizing gas for sterilization, and then sealing the contents to allow them to circulate. The packaging container comprises a container body, the container body comprising: a container portion having an opening at the top and containing the contents, and a flange portion extending outward from the opening edge of the container portion; the flange portion has: a cover member covering the opening is sealed in a single sealing process; The primary sealing area of the secondary seal and the secondary sealing area of the aforementioned cover member that is secondary sealed in the secondary sealing process after the primary sealing; and the aforementioned flange portion is configured such that: after the aforementioned cover member and the aforementioned primary sealing area are sealed, a flow path is formed between it and the aforementioned cover member for gas to flow between the outside and the aforementioned container, and after the aforementioned cover member and the aforementioned secondary sealing area are sealed together, the aforementioned flow path is closed.

The packaging container of this structure can be used as a container that contains the contents in the storage part and seals the primary sealing area of the cover member and the flange part, and then sterilizes the contents by circulating the sterilizing gas in the storage part through the flow path, and then seals the secondary sealing area of the cover member and the flange part.

In this packaging container, when the primary sealing area and the lid member are sealed, when the contents are sterilized, the sterilizing gas is allowed to flow from the bottom of the flange through the flow path into the container, thereby sterilizing the contents in the container.

Furthermore, in this 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 sterilizing gas, it is not easy for fallen bacteria to be mixed into the container through the flow path. In addition, since the flow path is sealed by the secondary sealing area and the cover member, the packaging container can completely seal the contents by sealing with the cover member.

In addition, in the aforementioned flange portion of the aforementioned packaging container, at least one through hole penetrating the aforementioned flange portion may be provided at a location further inward than the aforementioned primary sealing area, and the aforementioned through hole may also be configured in a manner that becomes a part of the aforementioned flow path.

According to this structure, after the first sealing process, the sterilizing gas flows from the bottom of the flange through the aforementioned through hole which becomes a part of the flow path into the storage part, thereby sterilizing the food in the storage part.

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

According to this structure, when the through hole is set, part of the flange portion will not be broken, and the flange portion will not be generated. Therefore, it is possible to prevent the flange portion from being mixed into the storage portion.

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

According to this structure, by forming a crack on the flange, a through hole and the uppermost part of the flange can be formed at the same time.

Furthermore, in the aforementioned packaging container, a portion of the aforementioned flange portion deformed toward the aforementioned upward direction may also have a curved surface that bulges toward the upward direction.

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

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

According to this structure, from the time when the primary sealing process is performed to the time when the secondary sealing process is performed, that is, when the contents are sterilized, since the cover member is supported by the uppermost portion of the aforementioned flange, the sterilizing gas can more reliably flow into the storage portion through the formed flow path.

In addition, in the aforementioned packaging container, the aforementioned flange portion may also be provided on the entire circumference of the opening edge of the aforementioned storage portion, and the aforementioned through-area may also be provided in plural numbers and arranged at opposite positions across the aforementioned storage portion.

According to this structure, by allowing the gas to flow from both sides of the storage part through the through holes arranged across the storage part, uneven heating of the food can be suppressed.

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

According to this structure, from the time when the primary sealing process is performed to 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, and the primary sealing area maintains the aforementioned gap as a part of the flow path, 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.

In addition, in the aforementioned packaging container, the aforementioned storage portion may also include a bottom plate on which the contents are placed, and the upper surface of the aforementioned bottom plate may also have a concave-convex shape.

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

The packaging container of the present invention may also be equipped with a cover member, and the aforementioned container body and the aforementioned cover member may also be composed of a multi-layer structure including at least one gas barrier layer.

According to this structure, by providing the container body or the cover member with a gas barrier layer, the sterilization state in the packaging container can be maintained for a longer period of time.

[Effect of the invention]

From the above content, according to the present invention, a packaging container can be provided that can be preferably used when sterilizing the contents and can maintain the quality of the sterilized contents for a long period of time.

1: Packaging container

2: Storage area

3: Flange

4: Container body

20: Open mouth

21: Opening up

22: Base plate

23: Side wall

30: Upper surface of flange

31: Primary sealing area

32: Secondary sealing area

33: Uppermost part of flange

33A: The top of the first flange

33B: The uppermost part of the second flange

34: Lower flange

36: Through area

220: Upper surface of the bottom plate

221: Bottom surface of the base plate

222: Bottom plate protrusion

223: Bottom plate slope

330: Upper surface of the uppermost part of the flange

340: Upper surface of the lower flange

360: Groove

361: Upper surface

Claims (14)

A packaging container is used for sterilization by exposing the contents contained therein to a sterilizing gas for sterilization, and then sealing the contents to allow them to circulate. The packaging container is provided with a container body, which includes: a storage portion having an opening at the top and storing the contents, and a flange portion extending outward from the opening edge of the storage 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 twice with the cover member in a secondary sealing process after the primary sealing process so that the contents are completely sealed; The uppermost portion of the flange, whose upper surface is located at the uppermost of the upper surfaces of the flange portion; The lower part of the flange has an upper surface located below the upper surface of the uppermost part of the flange; and At least one through area is located further inward than the aforementioned primary sealing area and is provided with a through hole that penetrates the aforementioned flange; The flange portion is configured such that after the lid member and the primary sealing area are sealed, a flow path is formed between the lid member and the lower portion of the flange supported by the uppermost portion of the flange, which allows the air in the container to be degassed to the outside and allows the sterilizing gas to flow from the outside into the container. During the period of degassed air in the container and the period of flowing the sterilizing gas into the container, the flow path is maintained in an open state. After the lid member and the secondary sealing area are sealed, the flow path is closed. A packaging container as described in claim 1, wherein the through hole is formed by forming a crack on a portion of the through area. The packaging container as described in claim 2, wherein the through-area has a curved surface that bulges upward, and the upper end of the curved surface constitutes the uppermost portion of the flange. A packaging container as described in claim 2, wherein the through-area is a recessed portion recessed downward, and the crack is formed in the recessed portion. The packaging container as described in claim 1, wherein the flange is provided on the entire circumference of the opening edge of the container, and a plurality of through-areas are provided and arranged at opposite positions across the container. A packaging container is used to expose the contents contained therein to a sterilizing gas for sterilization, and then seal the contents to allow them to circulate. The packaging container has a container body, which includes: a container portion having an opening at the top and containing the contents, and a flange portion extending outward from the opening edge of the container portion; The flange portion has: A primary sealing area, which is sealed once with a cover member covering the opening in a primary sealing process; and A secondary sealing area, which is secondary sealed with the cover member in a secondary sealing process after the primary sealing process; The flange is configured such that after the cover member and the primary sealing area are sealed, a flow path is formed between the flange and the cover member, which allows the air in the container to be degassed to the outside and allows the sterilizing gas to flow from the outside into the container. During the degassed period and the sterilizing gas flowing into the container, the flow path is kept open. After the cover member and the secondary sealing area are sealed, the flow path is closed. In the flange, at least one through hole is provided at a position further inside the primary sealing area and penetrating the flange. The through hole is configured to be a part of the flow path. A packaging container as described in claim 6, wherein the through hole is formed by forming a crack on a portion of the flange portion. The packaging container as described in claim 7, wherein the flange portion has: an uppermost portion of the flange formed by deforming a portion of the flange portion upward with the crack as a boundary, and the flow path is formed between the lid member supported by the uppermost portion of the flange and the flange portion. A packaging container as described in claim 8, wherein a portion of the flange portion deformed toward the upward direction has a curved surface that bulges toward the upward direction. The packaging container as described in claim 6 or 7, wherein the flange portion has: a flange uppermost portion, whose upper surface is located at the uppermost of the upper surfaces of the flange portion, and the flow path is formed between the lid member and the flange portion before being supported by the flange uppermost portion. A packaging container as described in any one of claims 6 to 9, wherein the flange is provided on the entire circumference of the opening edge of the container, and a plurality of through holes are provided and arranged at opposite positions across the container. The packaging container as described in claim 6, wherein the upper surface of the primary sealing area is located at the top of the upper surface of the flange portion, the upper surface of the secondary sealing area is located below the upper surface of the primary sealing area, the flange portion is configured such that after the lid member 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 lid member, the gap is configured to become a part of the flow path. A packaging container as described in any one of claims 1 to 9, wherein the storage portion includes a bottom plate on which the contents are placed, and the upper surface of the bottom plate has a concave-convex shape. The packaging container as described in any one of claims 1 to 9 further comprises a cover member, The container body and the cover member are composed of a multi-layer structure including at least one gas barrier layer.

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