Lid body and packaging container

Abstract

To provide a lid body capable of mitigating impact at the time of contact between a stacked lower packaging container and an upper packaging container and easily fixing a position when stacked, and a packaging container.SOLUTION: In a lid body 100 for a packaging container 300 that is rectangular in plan view and has a top surface 110 and a side surface 120 outside the top surface 110, the boundaries between adjacent side surfaces 120 and the boundaries between the top surface 110 and the side surface 120 are arc-shaped, and the size of the radius of curvature at two points on one diagonal corner of a corner 170 of the top surface 110 is different from the size of the radius of curvature at two points on the other diagonal corner of the corner 170 of the top surface 110.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lid and a packaging container. [Background technology]

[0002] BACKGROUND ART Packaging containers for storing food such as prepared dishes and sushi have been used in supermarkets, convenience stores, and the like.

[0003] There are various types of packaging containers, and the packaging container of Patent Document 1 is configured to be stackable. Specifically, the corners of the lid are arc-shaped, and the legs of the container body of the packaging container fit onto the lid, allowing for stacking. Furthermore, because the corners of the lid are arc-shaped, when stacking or adjusting the stacking position, the lower packaging container and the upper packaging container come into smooth contact, reducing impact and protecting the contents. However, the upper packaging container is slippery, which could cause the upper packaging container to shift position or fall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4418147 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, in consideration of the above problem, the present invention provides a lid body and a packaging container that can reduce the impact when a lower packaging container comes into contact with an upper packaging container when stacked, and that can easily fix the position when stacked. [Means for solving the problem]

[0006] In order to solve the above problem, the lid body of claim 1 of the present invention is a lid body for a packaging container that is rectangular in plan view and has a top surface portion and side surfaces outside the top surface portion, and is characterized in that the boundaries between adjacent side surfaces and the boundaries between the top surface portion and the side surfaces are arc-shaped, and the magnitudes of the radii of curvature (R1, R2) of the cross-section at two diagonal points on one corner of the top surface portion are different from the magnitudes of the radii of curvature (R3, R4) of the cross-section at two diagonal points on the other corner of the top surface portion.

[0007] According to the above features, the boundaries between adjacent side portions and the boundaries between the top and side portions are configured in an arc shape, improving visibility from diagonally above. Furthermore, the corner portion located at one diagonal corner has a different radius of curvature from the corner portion located at the other diagonal corner, resulting in an asymmetrical shape of the top portion of the lid, which gives consumers a sense of visual change. Furthermore, the corner portion located at one diagonal corner has a smaller radius of curvature than the other corner, making the corner portion with the smaller radius of curvature easier to grip with both hands of a consumer. Furthermore, the corner portion with the larger radius of curvature has the effect of reducing impact when the lower packaging container comes into contact with the upper packaging container, while the corner portion with the smaller radius of curvature has the effect of making it easier to secure the positions of the packaging containers when stacked.

[0008] In order to solve the above problem, the lid body according to claim 2 of the present invention is characterized in that the radius of curvature (R5) of the vertical cross section at two points on one diagonal corner of the corner portion of the top surface is different from the radius of curvature (R6) of the vertical cross section at two points on the other diagonal corner of the corner portion of the top surface.

[0009] According to the above feature, on the side with a larger radius of curvature in the longitudinal cross section, the corner is smoothly curved, allowing the upper packaging container to move smoothly along the smooth corner of the lower packaging container. As a result, the upper packaging container can be easily stacked on the corner of the lower packaging container. Furthermore, because the upper packaging container moves smoothly, there is less impact during movement, preventing the contents of the upper packaging container from collapsing. On the other hand, on the side with a smaller radius of curvature in the longitudinal cross section, the corner with a smaller radius of curvature is not smooth and is angular compared to the corner with a larger radius of curvature. Therefore, when the upper packaging container moves onto the corner with a smaller radius of curvature of the lower packaging container, the upper packaging container overlaps by fitting into the corner. As a result, the upper packaging container easily fits into the corner of the lower packaging container, and further, the fitted state is easily maintained and it is less likely to slip out of place.

[0010] In order to solve the above problem, the lid according to claim 3 of the present invention is characterized in that the top surface and the side surface are formed of surfaces without any irregularities.

[0011] According to the above feature, visibility from above and from the side is improved.

[0012] In order to solve the above problem, the packaging container of claim 4 of the present invention is a stackable packaging container comprising a lid body as described in claim 1 or claim 2 and a container body, wherein the container body has legs on the bottom surface that protrude downward from the bottom surface, the inner walls of the legs are arc-shaped and have a shape that corresponds to the arc shape of the corners of the top surface of the lid body, and are configured so that they can fit closely together, and the radius of curvature of the inner walls of the legs at two diagonal points on one corner of the bottom surface is different from the radius of curvature of the inner walls of the legs at two diagonal points on the other corner of the bottom surface.

[0013] According to the above feature, the legs of the upper packaging container are accurately overlapped with the corners of the lid (top surface) of the lower packaging container, making it easy to maintain the overlapped state and preventing misalignment.

[0014] In order to solve the above problem, the packaging container of claim 5 of the present invention is a stackable packaging container comprising the lid body of claim 3 and a container body, wherein the container body has legs on the bottom surface that protrude downward from the bottom surface, the inner walls of the legs are arc-shaped and have a shape that corresponds to the arc shape of the corners of the top surface of the lid body, and are configured so that they can fit closely together, and the radius of curvature of the inner walls of the legs at two diagonal points on one corner of the bottom surface is different from the radius of curvature of the inner walls of the legs at two diagonal points on the other corner of the bottom surface.

[0015] According to the above feature, the legs of the upper packaging container are accurately overlapped with the corners of the lid (top surface) of the lower packaging container, making it easy to maintain the overlapped state and preventing misalignment. [Effects of the Invention]

[0016] The lid and packaging container of the present invention can absorb the impact when a lower packaging container comes into contact with an upper packaging container when stacked, and can easily fix the positions when stacked. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is an overall perspective view of the lid of the present invention. [Figure 2] 1A is a plan view of the lid body, and FIG. 1B is a front view of the lid body. [Figure 3] (a) is an A-A cross-sectional view, (b) is a B-B cross-sectional view, (c) is a C-C cross-sectional view, and (d) is a D-D cross-sectional view. [Figure 4] FIG. 1(a) is an overall perspective view of a container body of the present invention, and FIG. 1(b) is a front view of the container body. [Figure 5](a) is a back view of the container body, (b) is an enlarged back view of the area around one corner of the container body, (c) is an E-E cross-sectional view, (d) is an enlarged back view of the area around the other corner of the container body, and (e) is an F-F cross-sectional view. [Figure 6] FIG. 1(a) is a front view of the packaging containers of the present invention stacked in layers, and FIG. 1(b) is a plan view of the packaging containers stacked in layers. [Figure 7] 6(b) is an enlarged plan view of the vicinity of P2 in FIG. 6(b); (c) is a cross-sectional view taken along line G-G; and (d) is a cross-sectional view taken along line H-H. [Figure 8] FIG. 2(a) is a front view of the packaging containers properly stacked, and FIG. 2(b) is a plan view of the packaging containers properly stacked. [Figure 9] (a) is an enlarged plan view of the vicinity of P1 in FIG. 8(b), (b) is an enlarged plan view of the vicinity of P2 in FIG. 8(b), (c) is a cross-sectional view taken along II, and (d) is a cross-sectional view taken along JJ. [Explanation of symbols]

[0018] 100 Lid 110 Top section 120 Side part 170 Corner section 300 Packaging containers DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification, "upward" refers to a direction that faces upward in the vertical direction when the packaging container is placed on a horizontal surface, and "downward" refers to a direction that faces downward in the vertical direction.

[0020] First, Fig. 1 to Fig. 3 show a lid 100 of a packaging container 300 according to the present invention. Fig. 1 is an overall perspective view of the lid 100, Fig. 2(a) is a plan view of the lid 100, Fig. 2(b) is a front view of the lid 100, Fig. 3(a) is an A-A cross-sectional view, Fig. 3(b) is a B-B cross-sectional view, Fig. 3(c) is a C-C cross-sectional view, and Fig. 3(d) is a D-D cross-sectional view.

[0021] As shown in FIGS. 1 to 3 , the lid 100 is made of a synthetic resin sheet and has a shallow dish shape that opens downward. It has a generally rectangular shape in plan view with corners 170 at its four corners. The lid 100 has a flat, horizontally extending top surface 110, side surfaces 120 that extend downward from the top surface 110, flat flanges 130 that extend outward from the side surfaces 120, and a skirt portion 140 that extends downward from the flanges 130. The skirt portion 140, located at the corners 170 of the lid 100, has a lid-side fitting portion 150 that is convex inward. The side surfaces 120, the flanges 130, and the skirt portion 140 are provided continuously or intermittently around the entire periphery of the lid 100. Although the lid 100 has a generally rectangular shape in plan view, the shape is not limited thereto and may have any shape, such as a generally polygonal or circular shape in plan view.

[0022] Furthermore, the boundary 121 between adjacent side portions 120 is formed in an arc shape that convex outward. Furthermore, the boundary 121 between the side portions 120 is located at a corner portion 170 of the lid 100. Furthermore, the boundary 111 between the top surface portion 110 and the side portion 120 is formed in an arc shape that convex outward. In this way, the boundary 121 between adjacent side portions 120 and the boundary 111 between the top surface portion 110 and the side portion 120 are configured in an arc shape, thereby improving visibility from diagonally above.

[0023] 2, the corner portions 170 located at diagonal corners of the top surface portion 110 have the same radius of curvature. Specifically, in a plan view, the radii of curvature R1 and R2 of the corner portions 170 located at one diagonal corner of the top surface portion 110 are equal. Each of the radii of curvature R1 and R2 is the radius of curvature in a cross-sectional view of each corner portion 170 located at one diagonal corner. Also, in a plan view, the radii of curvature R3 and R4 of the corner portions 170 located at the other diagonal corner of the top surface portion 110 are equal. Each of the radii of curvature R3 and R4 is the radius of curvature in a cross-sectional view of each corner portion 170 located at the other diagonal corner. The magnitudes of the radii of curvature (radius of curvature R1, radius of curvature R2) at two points on one diagonal corner of corner portion 170 of top surface portion 110 are different from the magnitudes of the radii of curvature (radius of curvature R3, radius of curvature R4) at two points on the other diagonal corner of corner portion 170 of top surface portion 110. In Figure 2, the radii of curvature (radius of curvature R1, radius of curvature R2) at two points on one diagonal corner of corner portion 170 of top surface portion 110 are larger than the radii of curvature (radius of curvature R3, radius of curvature R4) at two points on the other diagonal corner of corner portion 170 of top surface portion 110, but this is not limited to this, and the radii of curvature (radius of curvature R1, radius of curvature R2) at two points on one diagonal corner of corner portion 170 of top surface portion 110 may be smaller than the radii of curvature (radius of curvature R3, radius of curvature R4) at two points on the other diagonal corner of corner portion 170 of top surface portion 110. In this way, the radii of curvature of corner portions 170 located at one diagonal angle (radii of curvature R1, radius of curvature R2) are different from the radii of curvature of corner portions 170 located at the other diagonal angle (radii of curvature R3, radius of curvature R4), so that top surface 110 of lid body 100 has an asymmetrical shape, which makes the consumer perceive a change in appearance. Also, because the radii of curvature of corner portions 170 located at one diagonal angle are smaller than the other corner portion 170, the corner portion 170 with the smaller radius of curvature is easier to grip with both hands of a consumer, etc.

[0024] 3(a), at the corner portions 170 located at two diagonal corners of the top surface portion 110, the boundaries 111 between the top surface portion 110 and the side surface portion 120 are curved even in a vertical cross section perpendicular to the top surface portion 110. As shown in FIG. 3(c), at the corner portions 170 located at the other diagonal corners of the top surface portion 110, the boundaries 111 between the top surface portion 110 and the side surface portion 120 are curved even in a vertical cross section perpendicular to the top surface portion 110. The radius of curvature R5 of the boundary 111 located at one corner portion 170 in the vertical cross section shown in FIG. 3(a) is larger than the radius of curvature R6 of the boundary 111 located at the other corner portion 170 in the vertical cross section shown in FIG. 3(c).

[0025] Although the boundary 111 located at each corner portion 170 has a notch 112 recessed inward, the present invention is not limited to this, and the boundary 111 located at the corner portion 170 may not have a notch 112, and the entire boundary 111 may be a smoothly curved surface with no steps between it and the side surface portion 120. In this case, a smooth surface (for example, a curved surface) is provided from the top surface portion 110 to the side surface portion 120, thereby improving visibility from above and the side.

[0026] The lid body 100 is formed by sheet molding (e.g., vacuum molding, pressure molding, hot plate molding) using a sheet-shaped synthetic resin with a thickness of approximately 0.1 mm to 1.0 mm (millimeters). For example, the material for the lid body 100 may be polystyrene, polypropylene, polyethylene, A-PET, polylactic acid, or biaxially stretched versions of these.

[0027] Next, Fig. 4 and Fig. 5 show the container body 200 of the packaging container 300 according to the present invention. Fig. 4(a) is an overall perspective view of the container body 200, Fig. 4(b) is a front view of the container body 200, Fig. 5(a) is a back view of the container body 200, Fig. 5(b) is an enlarged back view of the periphery of one corner portion 270 of the container body 200, Fig. 5(c) is an E-E cross-sectional view, Fig. 5(d) is an enlarged back view of the periphery of the other corner portion 270 of the container body 200, and Fig. 5(e) is an F-F cross-sectional view.

[0028] As shown in FIGS. 4 and 5 , the container body 200 is made of a synthetic resin sheet, has a shallow dish shape that opens upward, and is generally rectangular in plan view with corner portions 270 at the four corners. The container body 200 includes a flat, horizontally extending bottom surface 210, side surfaces 220 that extend upward from the bottom surface 210, flat flange portions 230 that extend outward from the side surfaces 220, and a skirt portion 240 that extends downward from the flange portions 230. The skirt portion 240, located at the corner portions 270, is provided with a container-side fitting portion 250 that is concave inward. The side surfaces 220, the flange portions 230, and the skirt portion 240 are provided continuously or intermittently around the entire periphery of the container body 200. While the container body 200 has a generally rectangular shape in plan view, the shape is not limited thereto and may be any shape, such as a generally polygonal or generally circular shape in plan view.

[0029] In addition, a leg portion 280 is provided at a corner portion 270 of the bottom surface portion 210, protruding downward from the bottom surface portion 210. An inner peripheral wall 281 of the leg portion 280 has an arc shape that corresponds to the arc shape of the corner portion 170 of the top surface portion 110 of the lid body 100.

[0030] 5, the radii of curvature of the inner peripheral walls 281 of the legs 280 located at diagonal corners of the bottom surface portion 210 are equal. Specifically, in rear view (as seen from the rear surface side as shown in FIG. 5(a)), the radii of curvature R1 and R2 of the inner peripheral walls 281 of the legs 280 located at one diagonal corner of the bottom surface portion 210 are equal. The radii of curvature R1 and R2 of the inner peripheral walls 281 of the legs 280 are equal to or approximate to the radii of curvature R1 and R2 of the corner portions 170 located at one diagonal corner of the top surface portion 110 of the lid 100. In rear view, the radii of curvature R3 and R4 of the inner peripheral walls 281 of the legs 280 located at the other diagonal corner of the bottom surface portion 210 are equal. The radii of curvature R3 and R4 of the inner peripheral wall 281 of each leg portion 280 are equal to or approximate to the radii of curvature R3 and R4 of the corner portion 170 located at the other diagonal corner of the top surface portion 110 of the lid body 100.

[0031] The radii of curvature (radius of curvature R1, radius of curvature R2) of inner wall 281 of leg portion 280 at two diagonal points on one side of corner portion 270 of bottom portion 210 are different from the radii of curvature (radius of curvature R3, radius of curvature R4) of inner wall 281 of leg portion 280 at two diagonal points on the other side of corner portion 270 of bottom portion 210. In Figure 5, the radii of curvature (radius of curvature R1, radius of curvature R2) of inner wall 281 of leg portion 280 at two points on one diagonal corner of corner portion 270 of bottom portion 210 are larger than the radii of curvature (radius of curvature R3, radius of curvature R4) of inner wall 281 of leg portion 280 at two points on the other diagonal corner of corner portion 270 of bottom portion 210, but this is not limited to this, and the radii of curvature (radius of curvature R1, radius of curvature R2) of inner wall 281 of leg portion 280 at two points on one diagonal corner of corner portion 270 of bottom portion 210 may be smaller than the radii of curvature (radius of curvature R3, radius of curvature R4) of inner wall 281 of leg portion 280 at two points on the other diagonal corner of corner portion 270 of bottom portion 210.

[0032] 5(c), the inner peripheral walls 281 of the leg portions 280 at two locations on one diagonal corner of the corner portion 270 of the bottom surface portion 210 are also curved in a vertical cross section perpendicular to the bottom surface portion 210. Furthermore, as shown in FIG. 5(e), the inner peripheral walls 281 of the leg portions 280 at two locations on the other diagonal corner of the corner portion 270 of the bottom surface portion 210 are also curved in a vertical cross section perpendicular to the bottom surface portion 210. The radius of curvature R5 in the vertical cross section of the inner peripheral wall 281 of the leg portion 280 located at one corner portion 270 shown in FIG. 5(c) is larger than the radius of curvature R6 in the vertical cross section of the inner peripheral wall 281 of the leg portion 280 located at the other corner portion 270 shown in FIG. 5(e). 5(c), the radius of curvature R5 of the inner peripheral wall 281 of the leg portion 280 located at one corner portion 270 is equal to or approximate to the radius of curvature R5 of the boundary 111 located at one corner portion 170 shown in FIG. 3(a). Further, the radius of curvature R6 of the inner peripheral wall 281 of the leg portion 280 located at the other corner portion 270 shown in FIG. 5(e) is equal to or approximate to the radius of curvature R6 of the boundary 111 located at the other corner portion 170 shown in FIG. 3(c).

[0033] The container body 200 is formed by sheet molding (e.g., vacuum molding, compressed air molding, hot plate molding) using a sheet-shaped synthetic resin with a thickness of approximately 0.1 mm to 1.0 mm (millimeters). For example, the material for the container body 200 may be polystyrene, polypropylene, polyethylene, A-PET, polylactic acid, or biaxially stretched versions of these.

[0034] Next, Figures 6 and 7 show a state in which packaging containers 300 in which lid bodies 100 are attached to container bodies 200 are stacked. Figure 6(a) is a front view of the packaging containers 300 stacked, Figure 6(b) is a plan view of the packaging containers 300 stacked, Figure 7(a) is an enlarged plan view of the vicinity of P1 in Figure 6(b), Figure 7(b) is an enlarged plan view of the vicinity of P2 in Figure 6(b), Figure 7(c) is a cross-sectional view taken along G-G, and Figure 7(d) is a cross-sectional view taken along H-H.

[0035] As shown in Fig. 6, the packaging container 300 is attached so that the lid 100 is placed over the container body 200 and sealed. At this time, the lid-side fitting portion 150 of the lid 100 is tightly fitted into the container-side fitting portion 250 of the container body 200. In addition, another packaging container 300 is stacked on top of the lower packaging container 300. Here, the case where the upper packaging container 300 is stacked with a misalignment relative to the lower packaging container 300 is shown.

[0036] 6 and 7, when the upper packaging container 300 is stacked in a misaligned state, the leg portion 280 of the container body 200 of the upper packaging container 300 is misaligned from the corner portion 170 of the lid body 100 of the lower packaging container 300. Therefore, the upper packaging container 300 is stacked in a tilted state relative to the lower packaging container 300. In FIG. 7, the corner portion 170 of the lid body 100 is shown with diagonal lines for easy viewing.

[0037] Therefore, when returning the upper packaging container 300 to the correct position, the packaging container 300 is moved so that the leg portion 280 of the upper packaging container 300 fits snugly onto the corner portion 170 of the lower packaging container 300, as shown in Figures 8 and 9. Figure 8(a) is a front view of the packaging containers 300 correctly stacked, Figure 8(b) is a plan view of the packaging containers 300 correctly stacked, Figure 9(a) is an enlarged plan view of the vicinity of P1 in Figure 8(b), Figure 9(b) is an enlarged plan view of the vicinity of P2 in Figure 8(b), Figure 9(c) is a cross-sectional view taken along line II, and Figure 9(d) is a cross-sectional view taken along line JJ.

[0038] When returning the upper packaging container 300 to its correct position, as shown in FIG. 7(a), the corner portion 170 with a large radius of curvature R1 is smoothly curved, allowing the leg portion 280 to move smoothly along the smooth corner portion 170. As a result, as shown in FIG. 9(a), the leg portion 280 of the upper packaging container 300 can be easily placed on the corner portion 170 of the lower packaging container 300. Furthermore, because the leg portion 280 moves smoothly along the corner portion 170, there is little impact during movement, preventing the contents of the upper packaging container 300 from collapsing. Note that, because the radius of curvature R1 of the corner portion 170 is large at two locations (see P1 and P3 in FIG. 6) of the corner portion 170 located diagonally on the top surface 110, the above-mentioned effect can be obtained whether the upper packaging container 300 is displaced toward P1 or P3.

[0039] On the other hand, as shown in Fig. 7(b), the corner portion 170 with a small curvature radius R3 is not smooth and is angular compared to the corner portion 170 with a large curvature radius R1. Therefore, when the leg portion 280 moves to the corner portion 170 with the small curvature radius R3, the leg portion 280 overlaps the corner portion 170 so as to fit into the corner portion 170. As a result, as shown in Fig. 9(b), the leg portion 280 of the upper packaging container 300 easily fits into the corner portion 170 of the lower packaging container 300, and further, the fitted state is easily maintained and it is difficult to shift. Note that, since the curvature radius R3 of the corner portion 170 is small at two locations (see P2 and P4 in Fig. 6) of the corner portion 170 located diagonally on the top surface portion 110, the above-mentioned effect can be obtained whether the upper packaging container 300 shifts to the P2 side or the P4 side.

[0040] In this way, in the lid body 100 of the present invention, the magnitude of the radius of curvature at two points on one diagonal corner of the corner portion 170 of the top surface portion 110 is different from the magnitude of the radius of curvature at two points on the other diagonal corner of the corner portion 170 of the top surface portion 110, so that the corner portion 170 on the side with the larger radius of curvature R1 has the effect of mitigating the impact when the lower packaging container 300 and the upper packaging container 300 come into contact, and the corner portion 170 on the side with the smaller radius of curvature R3 has the effect of making it easier to fix the position when stacked.

[0041] 7(a), the inner peripheral wall 281 of the leg portion 280 corresponding to one corner portion 170 also has the same or an approximate radius of curvature R1 as the corner portion 170, so that the inner peripheral wall 281 of the leg portion 280 is configured to have a shape that corresponds to the corner portion 170 of the lid body 100 and to be able to fit closely to it. As a result, as shown in FIG. 9(a), the leg portion 280 of the upper packaging container 300 precisely overlaps with the corner portion 170 of the lower packaging container 300, making it easy to maintain this overlapping state and preventing misalignment.

[0042] 7(c), the radius of curvature R5 of the boundary 111 located at one corner portion 170 is large. Therefore, the boundary 111 is smoothly curved, and the leg portion 280 can move smoothly along the smooth boundary 111. As a result, as shown in FIG. 9(c), the leg portion 280 of the upper packaging container 300 can be easily stacked on the corner portion 170 of the lower packaging container 300. Furthermore, because the leg portion 280 moves smoothly along the boundary 111, there is little impact during movement, and it is possible to prevent the contents of the upper packaging container 300 from collapsing, etc.

[0043] 7(b), the inner peripheral wall 281 of the leg portion 280 corresponding to the other corner portion 170 also has the same or an approximate radius of curvature R3 as the corner portion 170, so that the inner peripheral wall 281 of the leg portion 280 is configured to have a shape that corresponds to the corner portion 170 of the lid body 100 and to be able to fit closely to it. As a result, as shown in FIG. 9(b), the leg portion 280 of the upper packaging container 300 precisely overlaps with the corner portion 170 of the lower packaging container 300, making it easy to maintain this overlapping state and preventing misalignment.

[0044] 7(d), the radius of curvature R6 of the boundary 111 located at the other corner portion 170 is smaller. Therefore, the boundary 111 with the smaller radius of curvature R6 is angular and not smooth compared to the boundary 111 with the larger radius of curvature R5. Therefore, when the leg portion 280 moves to the boundary 111 with the smaller radius of curvature R6, the leg portion 280 overlaps and fits into the corner portion 170. As a result, as shown in FIG. 9(d), the leg portion 280 of the upper packaging container 300 easily fits into the corner portion 170 of the lower packaging container 300, and further, the fitted state is easily maintained and is unlikely to shift. Note that the radius of curvature R5 of the vertical cross section at two diagonal points on one side of the corner portion 170 of the top surface 110 is larger than the radius of curvature R6 of the vertical cross section at two diagonal points on the other side of the corner portion 170 of the top surface 110, but is not limited to this. It is sufficient that the magnitude of the radius of curvature R5 of the vertical cross-section at two points on one diagonal corner of the corner portion 170 of the top surface portion 110 is different from the magnitude of the radius of curvature R6 of the vertical cross-section at two points on the other diagonal corner of the corner portion 170 of the top surface portion 110, and the magnitude of the radius of curvature R5 of the vertical cross-section at two points on one diagonal corner of the corner portion 170 of the top surface portion 110 may be smaller than the radius of curvature R6 of the vertical cross-section at two points on the other diagonal corner of the corner portion 170 of the top surface portion 110.

[0045] 9, when the leg portion 280 of the upper packaging container 300 is stacked accurately on the corner portion 170 of the lower packaging container 300, the lower end portion 283 of the upper leg portion 280 rests on the notch 112 of the corner portion 170. Therefore, the stacked state is more easily maintained and is less likely to shift.

[0046] The packaging container of the present invention is not limited to the above examples, and various modifications and combinations are possible within the scope of the claims and the scope of the embodiments, and these modifications and combinations are also included in the scope of rights.

Claims

1. A lid for a packaging container having a top surface and a side surface on the outside of the top surface, the lid having a rectangular shape in a plan view, The boundary between adjacent side surface portions and the boundary between the top surface portion and the side surface portion are configured in an arc shape, A lid for a packaging container, characterized in that the magnitudes of the radii of curvature (R1, R2) of the cross section at two diagonal points of one corner of the top surface are different from the magnitudes of the radii of curvature (R3, R4) of the cross section at two diagonal points of the other corner of the top surface.

2. The lid of the packaging container according to claim 1, characterized in that the radius of curvature (R5) of the vertical cross section at two diagonal points of one corner of the top surface portion is different from the radius of curvature (R6) of the vertical cross section at two diagonal points of the other corner of the top surface portion.

3. 3. The lid for a packaging container according to claim 1, wherein the top surface and the side surface are formed of smooth surfaces.

4. A stackable packaging container comprising the lid body according to claim 1 or 2 and a container body, The container body has a bottom surface provided with legs that protrude downward from the bottom surface, The inner peripheral wall of the leg portion has an arc shape, and the shape corresponds to the arc shape of the corner portion of the top surface of the lid, and is configured so that they can be in close contact with each other, A packaging container characterized in that the radius of curvature of the inner peripheral wall of the leg portion at two diagonal points on one corner of the bottom portion is different from the radius of curvature of the inner peripheral wall of the leg portion at two diagonal points on the other corner of the bottom portion.

5. A stackable packaging container comprising the lid body according to claim 3 and a container body, The container body has a bottom surface provided with legs that protrude downward from the bottom surface, The inner peripheral wall of the leg portion has an arc shape, and the shape corresponds to the arc shape of the corner portion of the top surface of the lid, and is configured so that they can be in close contact with each other, A packaging container characterized in that the radius of curvature of the inner peripheral wall of the leg portion at two diagonal points on one corner of the bottom portion is different from the radius of curvature of the inner peripheral wall of the leg portion at two diagonal points on the other corner of the bottom portion.

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