container

Abstract

To provide an excellent container that prevents loosening and wrinkling of sealing members caused by thermal deformation or the like. [Solution] The container body 10 comprises a bottom portion 12, a peripheral wall portion 13, and a flange portion 14, and the storage space 1A is surrounded by the peripheral wall portion 13 and the bottom portion 12. A sealing member 16 is placed on top of the flange portion 14, and the sealing member 16 and the flange portion 14 are heat-fused together, so that the upper opening 1B can be closed by the sealing member 16 due to the tension force on the sealing member 16 that covers the storage space 1A. A downward sloping portion 14K is formed on the outside of each side portion 14B, 14C of the flange portion 14, and the downward sloping portion 14K is deformed horizontally from the downward outward by the force F1 applied to the downward sloping portion 14K due to the heat-fusion when closing with the sealing member 16. A skirt portion 15 is formed on the outside of the downward sloping portion 14K, extending downward and outward, and the outer edge 15M is deformed from a curved shape to a straight shape by the force F2.

Description

Technical Field

[0001] The present invention relates to a container that can close (seal) the opening of a container body using a heat-sealing material.

Background Art

[0002] Conventionally, when selling fruits, vegetables, food, etc. at a retail store or the like, the opening of a container body containing fruits, vegetables, food, etc. is closed (sealed) with a heat-sealing material and then sold. Packages using a heat-sealing material (for example, Patent Document 1) have high convenience due to their sealing performance for maintaining the quality of the contents and easy opening property of the heat-sealing material, and thus further technological improvements have been made in recent years.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above package, in a container body formed by thermoforming a synthetic resin sheet, when using a heat-resistant material, even if the heat-sealing material is attached to the flange of the container body and heat-sealed, there is little thermal deformation of the container body. On the other hand, when using a container body made of a material with a low heat-resistant temperature, during the heat-sealing process, due to the residual stress (thermal history) during container forming, it has the property of returning to the sheet state and tends to be easily thermally deformed.

[0005] In particular, when covering and heating a heat-sealing member on the flange of the container body, the corner portion (corner) of the container body has a rigid shape (high strength) and does not thermally deform. On the other hand, since the side portion (between the corners) does not have a rigid shape (low strength), a phenomenon occurs where the side portion of the square and its surroundings do not become straight (see FIG. 14).

[0006] As a result, in containers that use a heat-sealing member as a lid, the heat-sealing member is affected by thermal deformation from the container, which can cause significant sagging or wrinkles in the heat-sealing member. When such sagging or wrinkles occur (dashed line SW in Figure 14), the overall appearance of the container deteriorates, which may lead to customer complaints.

[0007] The present invention was made to solve the above problems. Its purpose is to provide an excellent container that suppresses loosening and wrinkling of the sealing member caused by thermal deformation of the container body, etc., in the above-described embodiment. Furthermore, when the upper opening of the container body is closed with a sealing member, the outer edges of the skirt portion at the tip of each side of the flange portion of the container body are straight and do not have an irregular shape, thus providing an excellent container that can be neatly arranged when displayed and sold in retail stores, etc. ru. [Means for solving the problem]

[0008] To achieve the above objectives, the present invention has the following means. That is, as described in claim 1, a container body having a rectangular bottom portion that extends from the inside outward, peripheral wall portions that rise from each side and corner of the bottom portion, and flange portions that extend outward from each side and corner above the peripheral wall portion, forming a storage space surrounded by the peripheral wall portion and bottom portion below the flange portion, wherein a sealing member is superimposed around the flange portion that sandwiches the storage space, the sealing member and the flange portion are heat-fused together, and the upper opening of the container body can be closed with the sealing member by tension on a sheet member that covers the storage space, wherein the flange portion Each side forms a downward-sloping outward-inclined portion, and a skirt portion extending downward and outward is formed outside the downward-sloping portion, with the outer edge of the skirt portion having a curved portion that curves inward. Due to the force applied to the downward-sloping portion caused by heat fusion when the sealing member is closed, the downward-sloping portion deforms horizontally from the downward-outward direction, and further, due to the force applied to the curved portion caused by heat fusion when the sealing member is closed, the outer edge of the skirt portion deforms from a curved shape to a straight shape. It is characterized by the following:

[0009] Other examples of modifications include the following: A container body comprising a rectangular bottom portion that extends from the inside outward, peripheral walls rising from each side and corner of the bottom portion, and flange portions extending outward from each side and corner above the peripheral walls, forming a storage space surrounded by the peripheral walls and bottom portion below the flange portions, wherein a sealing member is superimposed around the flange portions that sandwich the storage space, and the sealing member and flange portions are heat-fused together, and the upper opening of the container body can be closed with the sealing member by tension on a sheet member that covers the storage space, A curved portion is formed on the inner side of each side of the flange, with the inner edge curving outward. The force applied to this curved portion due to heat fusion during sealing with the sealing member causes the curved portion to deform from a curved shape to a straight shape.

[0010] Other examples of modifications include the following:A container body comprising a rectangular bottom surface that extends from the inside outward, peripheral walls rising from each side and corner of the bottom surface, and flanges extending outward from each side and corner above the peripheral walls, forming a storage space surrounded by the peripheral walls and bottom surface below the flanges, wherein a sealing member is superimposed around the flanges that sandwich the storage space, and the sealing member and flanges are heat-fused together, and the upper opening of the container body can be closed by the tension on the sheet member covering the storage space with the sealing member. In order to seal the flange, ribs are provided around the flange to resist the force applied to the edges of the flange during heat fusion, thereby suppressing deformation around the ribs caused by heat fusion.

[0011] Other examples of modifications include the following: . In other words, in a container body comprising a rectangular bottom portion that widens from the inside outward, peripheral walls rising from each side and corner of the bottom portion, and flange portions extending outward from each side and corner above the peripheral walls, forming a storage space surrounded by the peripheral walls and bottom portion below the flange portions, a sealing member is placed around the flange portions that sandwich the storage space, and the sealing member and flange portions are heat-fused together, and the upper opening of the container body can be closed with the sealing member by the tension force on the sheet member that covers the storage space, in which each side of the flange portion forms a downward sloping portion that is inclined outward and downward, and the downward sloping portion deforms horizontally from the downward sloping portion due to the force applied to the downward sloping portion caused by the heat-fusion when closing with the sealing member. . [Effects of the Invention]

[0012] According to the present invention, the above-mentioned container provides an excellent container that suppresses loosening and wrinkling of the sealing member caused by thermal deformation of the container body, etc. Furthermore, when the upper opening of the container body is closed with a sealing member, the outer edges of the skirt portion at the tip of each side of the flange portion of the container body are straight and do not have an irregular shape, thus providing an excellent container that can be neatly arranged when displayed and sold in retail stores, etc. . [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of the container body of the first embodiment. [Figure 2] Figure 1 is a plan view of the container body. [Figure 3] Figure 1 is a front view of the container body. [Figure 4] Figure 3 is a magnified view of the main part, showing the area around the flange portion of the container body. [Figure 5] This is an explanatory diagram showing the state in which the sheet material is placed over the container body shown in Figure 3. [Figure 6] This is an explanatory diagram showing a magnified view of a part of the container body in Figure 2. [Figure 7] This is an explanatory diagram showing a magnified view of a part of the container body in Figure 2. [Figure 8] This is an explanatory diagram showing a magnified portion of the container in Figure 5. [Figure 9] This is an explanatory diagram of the container according to the second embodiment. [Figure 10] This is an explanatory diagram showing a magnified view of a portion of the container in Figure 9. [Figure 11] It is an explanatory diagram showing an enlarged part of the container of the third embodiment. [Figure 12] It is an explanatory diagram showing an enlarged part of the container of the fourth embodiment. [Figure 13] It is a diagram for checking and explaining the heat sealability of the container. [Figure 14] It is an explanatory diagram showing an enlarged part of a conventional container.

Explanation of Reference Numerals

[0014] 1 ··· Container, 1A ··· Storage space, 10 ··· Container body, 12 ··· Bottom surface part, 12H ··· Inside of the bottom surface part, 12R ··· Outside of the bottom surface part, 12A ··· Corner part of the bottom surface part, 12B ··· One side part (side part of the bottom surface part), 12C ··· Other side part (side part of the bottom surface part) 13 ··· Peripheral wall part, 13A ··· Corner part of the peripheral wall part, 13B ··· One side part (side part of the peripheral wall part), 13C ··· Other side part (side part of the peripheral wall part), 14 ··· Flange part, 14A ··· Corner part of the flange part, Sorting number: 240917P2 Japanese Patent Application No. 2024 - 160442 (Proof) Filing date: September 17, 2024 3 14B ··· One side part (side part of the flange part), 14C ··· Other side part (side part of the flange part), 14K ··· Downward slope part, 14Y ··· Curved part of the flange part 14M ··· Outer edge of the flange part, 14N ··· Inner edge of the flange part 14B ··· One side part (side part of the flange part), 14C ··· Other side part (side part of the flange part), 15 ··· Skirt part, 15M ··· Outer edge of the skirt part, 16 ··· Seal member, 15B ··· One side part (side part of the skirt part), 15C ··· Other side part (side part of the skirt part), L1 ··· Horizontal line, R1 ··· Rib

Modes for Carrying Out the Invention

[0015] The first to fourth embodiments of the container body of the present invention will be described below with reference to the drawings. The container body can be manufactured by thermoforming a sheet made of a synthetic resin (plastic material) such as polyolefin. The synthetic resin may be other than polyolefin, such as polyester, polystyrene resin, or other resins.

[0016] The lid material that covers the opening of the container body may be made of the same synthetic resin as the container body, but from the viewpoint of airtightness to maintain the quality of the contents and ease of opening, it is desirable to use a material suitable for heat sealing. The heat sealing material is preferably a multilayer resin made by adding functional materials such as anti-fogging or barrier properties to polyolefin.

[0017] The term "parallel" (as described below) used in the following explanation is not limited to parallel in the strict sense, but includes a degree of parallelism that can be considered parallel in the technical field used in the embodiment (hereinafter referred to as "the technical field").

[0018] Similarly, the term "horizontal" (as described later) is not limited to horizontal in the strict sense, but includes anything that can be considered horizontal in the relevant technical field. Similarly, the term "up and down" used in this text is not limited to vertical in the strict sense, but includes anything that can be considered vertical in the relevant technical field.

[0019] The vertical direction coincides with the Z-axis direction as shown in Figure 1, etc. The left-right and front-back directions are explained using the "X-axis" or "Y-axis direction" in container 1 as shown in Figure 1, etc. The Y-axis direction and the X-axis direction are orthogonal to each other, and the direction that intersects the Y-axis direction and the X-axis direction is called the "Z-axis direction".

[0020] Figures 1 to 3 are perspective views, plan views, and front views of the container 1 according to the first embodiment. The horizontal, vertical, and left-right directions of the container 1 are based on the state in which the container body 10 shown in Figure 1 is placed on a horizontal plane.

[0021] The container body 10 has a bottom surface 12 that is approximately square in plan view, as shown in Figures 1 to 3. The bottom surface 12 occupies a large area to secure the storage space 1A (described later) and has a shape that extends from the inside 12H to the outside 12R. The bottom surface 12 shown in Figures 1 and 2 has one side and the other side of a square shape, and in addition to the corner 12A, it has one side 12B and the other side 12C.

[0022] Note that the rectangular shape of the base portion 12 in plan view may also be rectangular in plan view, as shown in Figures 1 and 2. When the base portion 12 is set to be rectangular in plan view, one side 12B or the other side 12C of the base portion 12 forms a long side (short side) or short side (long side), and one side 12B and the other side 12C constitute a side.

[0023] The peripheral wall portion 13 is connected to the base portion 12 such that it rises up from the corner portion 12A, one side portion 12B, and the other side portion 12C of the base portion 12. If the base portion 12 is square in plan view, the peripheral wall portion 13 will also be square in plan view.

[0024] The peripheral wall portion 13 includes one side portion 13B and the other side portion 13C, in addition to each corner portion 13A. Each corner portion 13A is connected to each of the one side portion 13B and the other side portion 13C, respectively.

[0025] When the base portion 12 is set to be rectangular in plan view, the peripheral wall portion 13 is also set to be rectangular in plan view. Therefore, the peripheral wall portion 13 also has a long side portion and a short side portion, and each long side portion and each short side portion constitutes the respective sides 13B and 13C of the peripheral wall portion 13.

[0026] It is desirable that each corner 13A, each side 13B, and each other side 13C of the peripheral wall portion 13 be smoothly connected to each corner 12A, each side 12B, and each other side 12C of the base portion 12. The inner and outer surfaces of the peripheral wall portion 13 correspond to the inner surface 12H and outer surface 12R of the base portion 12.

[0027] A flange portion 14 extending from the inside to the outside is connected to the upper part of the peripheral wall portion 13. The flange portion 14 has one side portion 14B and another side portion 14C in addition to each corner portion 14A. Each corner portion 14A is connected to each of the one side portion 14B and each of the other side portions 14C, respectively.

[0028] When the peripheral wall portion 13 is set to be rectangular in plan view, the flange portion 14 is also set to be rectangular in plan view. Therefore, the flange portion 14 also has a long side portion and a short side portion, and each long side portion and each short side portion constitutes the respective side portions 14B and 14C. The inside and outside of the flange portion 14 correspond to the inside 12H and outside 12R of the bottom surface portion 12.

[0029] It is desirable that each corner 14A and each side 14B, 14C of the flange portion 14 be smoothly connected to each corner 13A and each side 13B, 13C of the peripheral wall portion 13.

[0030] One side 13B and the other side 13C of the peripheral wall portion 13 are connected to one side 14B and the other side 14C of the flange portion 14, respectively. A skirt portion 15 extending downward and outward is connected to the outside of the flange portion 14.

[0031] The skirt portion 15 includes, in addition to each corner portion 15A, one side portion 15B and the other side portion 15C. Each corner portion 15A is connected to each of the one side portion 15B and the other side portion 15C respectively (the outermost part of each side portion 15B, 15C is called the outer edge 15M (see Figure 4)).

[0032] Each corner 14A and each side 14B, 14C of the flange portion 14 are connected to each corner 15A and each side 15B, 15C of the skirt portion 15, respectively. It is desirable that each corner 14A, each one side 14B, and each other side 14C be smoothly connected to each corner 15A, each one side 15B, and each other side 15C, respectively.

[0033] When the flange portion 14 is set to be rectangular in plan view, the skirt portion 15 is also set to be rectangular in plan view. Therefore, the skirt portion 15 also has a long side and a short side, and each long side and each short side constitutes the sides 15B and 15C.

[0034] It is desirable that the outer ends of each side portion 14B, 14C of the flange portion 14 form a downward sloping portion that is inclined outward and downward. In this case, when the opening 1A is closed with the sealing member 16, the flange portions 14 overlap and are heated and fused together, and the force F1 caused by the heat fusion is applied to the downward sloping portion.

[0035] This force F1 allows the downward sloping portions on the outer ends of each side 14B and 14C to deform horizontally from the outside downward (along the horizontal line L1 (see Figure 4)), and when tension is applied to the sealing member 16, sufficient tension is applied when the sealing member 16 closes the opening 1A, thereby increasing its sealing function as a lid.

[0036] The container body 10 has a structure that includes a peripheral wall portion 13 rising from the bottom portion 12, a flange portion 14 extending outward from above the peripheral wall portion 13, and a sealing member 16 that closes the opening 1A. Therefore, the storage space 1A below the flange portion 14 is formed to be surrounded by the sealing member 16, the flange portion 14, the peripheral wall portion 13, and the bottom portion 12.

[0037] Regarding this storage space 1A, for example, when displaying and selling fruits, vegetables, or other food items in a retail store, it is desirable that it have sufficient volume to store the fruits, vegetables, or other food items. Furthermore, after storing fruits, vegetables, or other food items in the storage space 1A, the quality of the fruits, vegetables, or other food items can be ensured by covering (sealing) the upper opening 1B of the container body 10 with the sealing member 16.

[0038] To close the upper opening 1B with the sealing member 16, as described above, it is desirable to overlap the sealing member 16 around the flange portion 14 that sandwiches the storage space 1A, heat-fuse the sealing member 16 and the flange portion 14 together, and then cover (seal) the upper opening 1B of the container body 10 with the tension force on the sealing member 16 that covers the storage space 1A.

[0039] In order to close (seal) the upper opening 1B of the container body 10 containing food, etc., with a heat sealing material 16, as shown in Figures 5 and 8, the sealing member 16 is placed so as to cover the upper opening 1B and the flange portion 14 of the container body 10, and then attached to the flange portion 14 and heat-sealed.

[0040] As previously described, the corners (corners) of the container body 10, namely the corners 13A of the peripheral wall portion 13, the corners 14A of the flange portion 14, and the corners 15A of the skirt portion 15, have a rigid shape and are therefore resistant to thermal deformation.

[0041] On the other hand, since the edges 13B and 13C of the peripheral wall portion 13, the edges 14B and 14C of the flange portion 14, and the edges 15B and 15C of the skirt portion 15 are straight and not rigid, the squares of the peripheral wall portion 13, flange portion 14, and skirt portion 15 tend to become irregularly shaped. In particular, the edges 14B and 14C of the flange portion 14 tend to become concave inwards.

[0042] Therefore, as a first embodiment, as shown in Figure 6, a curved portion 14Y (indicated by multiple dots) is formed on the inside of each side portion 14B, 14C of the flange portion 14, where the inner edge 14N curves outward. In this case, the upper opening 1B of the container body 10 is closed by the sealing member 16, which is then heat-fused. The force F1 (see Figures 5 and 8) acting on the curved portion 14Y as a result of this deformation causes the outer edge 14M of the curved portion 14Y to change from a curved shape (see Figure 6) to a straight shape (see Figure 7).

[0043] As a result, the sealing members 16 are overlapped around the flange portion 14 that sandwiches the storage space 1A, from each corner 13A and each side portion 13B, 13C of the peripheral wall portion 13 to the container body 10, and the sealing members 16 and the flange portion 14 are heat-fused together. When the upper opening 1B of the container body 10 is closed by the sealing members 16 due to the tension on the sealing members 16 that cover the storage space 1A, the outer shape of the container body 10 remains straight and does not become irregular in shape, so the container bodies 10 can be arranged neatly when displayed and sold in retail stores, etc.

[0044] In this case, when the sealing member 16 and the flange portion 14 of the container body 10 are heat-fused together to close the upper opening 1B of the container body 10 with the sealing member 16, it is possible to suppress loosening or wrinkling of the sealing member 16 caused by thermal deformation or the like.

[0045] As described above, according to the first embodiment, a curved portion 14Y is formed on the inside of each side portion 14B, 14C of the flange portion 14, with the inner edge 14N curving outward. The force F1 applied to the curved portion 14Y due to heat fusion when the sealing member 16 closes the flange, causes the outer edge 14M of the curved portion 14Y to change from a curved shape (see Figure 6) to a straight shape (see Figure 7), thereby preventing deformation of each side portion 14B, 14C of the flange portion 14.

[0046] In this embodiment, the heat sealability of the container 1 of the above embodiment was confirmed using the sealing members 16 of multiple products, and the heat sealability of the conventional container was also confirmed (see Figure 13). As a result, products A and B performed comparably to comparative products A and B.

[0047] In other words, comparative products A and B, which have a similar configuration to Figure 14, may produce irregular shapes that are not straight due to the low strength of each side (between corners) of the flange extending outward from the top of the peripheral wall (wrinkle SW shown in Figure 14 may occur), but there are no problems with mechanical strength other than that issue. On the other hand, the actual products A and B do not produce irregular shapes like comparative products A and B, and furthermore, there are no problems with mechanical strength (no wrinkles as shown in Figure 14 occur).

[0048] Next, a second embodiment will be described with reference to Figures 9 and 10. In the container of the second embodiment, the same reference numerals are used for the same container components as in the above embodiment, and their description is omitted.

[0049] In the container 1 of the second embodiment, multiple ribs R1 are arranged around the flange portion 14 (inside each side 14B, 14C) to resist the force applied to each side 14B, 14C of the flange portion 14 during heat fusion for sealing with the sealing member 16, thereby suppressing deformation around the ribs R1 caused by heat fusion. Inside the flange portion 14 (inside each side 14B, 14C) as shown in Figure 9, the ribs R1 extend in the vertical direction (see Figure 10), and are arranged in groups of three along each side 14B, 14C of the flange portion 14 at regular intervals (see Figure 9).

[0050] As a result, in the container 1 of the second embodiment, when the upper opening 1B of the container body 10 is closed with the sealing member 16, the function of the rib R1, which resists the force applied to each side 14B, 14C of the flange portion 14, prevents the sides 14B, 14C of the flange portion 14 of the container body 10 from becoming irregularly shaped, so that they can be neatly arranged when displayed and sold in retail stores, etc.

[0051] Furthermore, similar to the first embodiment, in the container of the second embodiment, when the sealing member 16 and the flange portion 14 of the container body 10 are heat-fused together to close the upper opening 1B of the container body 10 with the sealing member 16, the function of the rib R1, which resists the force applied to each side portion 14B, 14C of the flange portion 14, can suppress loosening and wrinkles in the sealing member 16 caused by thermal deformation or the like.

[0052] Next, a third embodiment will be described using Figure 11. In the container of the third embodiment, the same reference numerals are used for the same container components as in the first embodiment, and their description is omitted. Figure 11 schematically shows the outer edge of the container, and is a front view of the main outer edges of each side portion 14B, 14C of the flange portion 14. Figure 11(A) shows the container before heat sealing (heat fusion), and Figure 11(B) shows it after heat sealing (heat fusion).

[0053] In the container of the third embodiment, the sealing member 16 forms downward-sloping portions 14K (see Figure 11(A)) on each side 14B and 14C of the flange portion 14, and the force F2 applied to the downward-sloping portions 14K due to heat fusion when the sealing member 16 closes causes the downward-sloping portions 14K to deform horizontally (see Figure 11(B)) from downward-sloping outwards. The downward-sloping portions 14K formed by each side 14B and 14C of the flange portion 14 produce the same effects as in the first embodiment.

[0054] In this case, when the upper opening 1B of the container body 10 is closed with the sealing member 16, the outer shape of each side portion 14B, 14C of the flange portion 14 of the container body 10 is straight and does not become an irregular shape, so that they can be neatly arranged when displayed and sold in retail stores, etc.

[0055] Furthermore, when the sealing member 16 and the flange portion 14 of the container body 10 are heat-fused together to close the upper opening 1B of the container body 10 with the sealing member 16, it is possible to suppress loosening or wrinkling of the sealing member 16 caused by thermal deformation or the like.

[0056] Next, the fourth embodiment will be described using Figure 12. In the container of the fourth embodiment, the same reference numerals are used for the same container components as in the first and third embodiments, and their descriptions are omitted. Figure 12 schematically shows the outer edge of the container, and is a combination of the front view and the top view of the main outer edge of the container shown in Figure 11. Figure 12(A) shows the container before heat sealing (heat fusion), and Figure 12(B) shows it after heat sealing (heat fusion).

[0057] In the fourth embodiment, as shown in Figure 12, the container 1 has a flange portion 14, where each side portion 14B, 14C forms a downward-sloping portion 14K that is inclined downward and outward. A skirt portion 15 is formed on the outside of each side portion 14B, 14C (downward-sloping portion 14K) of the flange portion 14, and the skirt portion 15 has a curved portion 15Y where the outer edge 15M is curved inward.

[0058] The force F2 applied to the curved portion 15Y due to the heat fusion when the sealing member 16 closes the opening can deform the outer edge 15M of the skirt portion 15 from a curved shape (see Figure 12(A)) to a straight shape (see Figure 12(B)) (see arrows in Figures 12(A) and 12(B)).

[0059] In this case, when the upper opening 1B of the container body 10 is closed with the sealing member 16, the outer edge 15M of the skirt portion 15 at the tip of each side portion 14B, 14C of the flange portion 14 of the container body 10 is straight and does not have an irregular shape, so that they can be neatly arranged when displayed and sold in retail stores, etc.

[0060] Furthermore, when the sealing member 16 and the flange portion 14 of the container body 10 are heat-fused together to close the upper opening 1B of the container body 10 with the sealing member 16, it is possible to suppress loosening or wrinkling of the sealing member 16 caused by thermal deformation or the like.

[0061] As another embodiment, an embodiment combining the first embodiment and the fourth embodiment may be adopted. Also, an embodiment combining the second embodiment and the fourth embodiment may be adopted as appropriate. Furthermore, an embodiment combining the third embodiment and the fourth embodiment may be adopted.

[0062] Furthermore, if necessary, embodiments may be adopted that combine the technical essentials of the first to fourth embodiments.

[0063] Furthermore, the container of the present invention is not limited to the above-described embodiments, and various modifications and combinations are possible within the scope of the claims and embodiments, and these modifications and combinations are also included within the scope of the patent rights.

Claims

[Claim 1] A rectangular base that widens from the inside outwards, The peripheral wall portion rising from each side and corner of the bottom portion, The peripheral wall portion is provided with flange portions extending outward from each side and each corner, With respect to the container body that forms a storage space surrounded by the lower peripheral wall portion and the bottom surface portion of the flange portion, In a container in which a sealing member is placed around the flange portion that encloses the storage space, the sealing member and the flange portion are heat-fused together, and the upper opening of the container body is closed by the tension applied to the sheet member that covers the storage space, Each side of the flange portion forms a downward sloping portion that is inclined outward and downward. A skirt portion is formed on the outside of the aforementioned downward sloping portion, extending downward and outward, and the outer edge of the skirt portion has a curved portion that curves inward. The force applied to the downward-sloping portion due to the heat fusion that occurs when the sealing member closes the area causes the downward-sloping portion to deform horizontally from the outside downward, and further, A container body characterized in that the outer edge of the skirt portion deforms from a curved shape to a straight shape due to the force applied to the curved portion caused by heat fusion when the sealing member closes the container.

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