Resin container

Abstract

To provide a resin container that can achieve space saving during transportation or storage, and is easily handled even when storing cooked contents.SOLUTION: A resin container comprises: a container body having a bottom wall part and a side wall part erected from the circumference of the bottom wall part, and an opening in the upper edge; and a lid body having a top wall part for detachably closing the opening. The lid body is formed with a lateral shift preventing part which receives the bottom wall part when the container body is placed on the lid body while directing upward the inner surface of the lid body, and prevents the container body from being shifted in the surface direction of the bottom wall part. The bottom wall part has a polygonal shape in a plane view. The lateral shift preventing part is a recess corresponding to the shape of the bottom wall part, and the lateral shift preventing part comprises an expansion recess expanding outward in a position in the corner part of the bottom wall part when the container body is placed on the lid body while directing upward the inner surface of the lid body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin container. [Background technology]

[0002] Resin containers obtained by molding resin sheets are used as food containers such as containers for take-out bento boxes, containers for frozen or refrigerated foods, containers for instant noodles, etc. For example, containers for take-out bento boxes and cooked foods such as cooked frozen or refrigerated foods are heated in a microwave oven with the contents housed inside. When the contents are cooked in a microwave oven, the heat from the heated contents is transferred to the container, causing the temperature of the container's exterior to rise. When the temperature of the container's exterior rises, insulating gloves or a tray are required when removing the container from the microwave oven or when eating the contents, making handling cumbersome.

[0003] In response to these problems, Patent Document 1 proposes a microwave rice cooking container that has a microwave-safe container body that can hold rice and water, and a microwave-safe lid that covers the top opening of the container body, with the container body being formed from a high-magnification foamed heat-resistant synthetic resin. Patent document 2 proposes a double container for microwave ovens in which a plastic inner container and an outer container are stacked so as to form a gap between the body and bottom of the inner and outer containers, and the open ends of the inner and outer containers are locked or fixed together to form an integrated unit. Patent Document 3 proposes a cooking container for a microwave oven in which a heat-insulating container is fitted around the body of a heat-resistant container with a gap between them. The inventions in Patent Documents 1 to 3 aim to suppress the temperature rise on the outer surface of the container after heating in a microwave oven. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-050672 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-189326 [Patent Document 3] Japanese Utility Model Application Publication No. 62-141108 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the invention of Patent Document 1 requires a container body with a high expansion ratio, which results in a bulky container body and requires a large space for transportation or storage of the container body. The inventions of Patent Documents 2 and 3 have a double-structured container body, which makes the container body bulky and requires a large space for transportation or storage of the container body. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin container that can save space during transportation or storage and is easy to handle even when it contains cooked food. [Means for solving the problem]

[0006] The resin container of the present invention comprises: a container body having a bottom wall portion and a side wall portion rising from the periphery of the bottom wall portion and having an opening at an upper end; a lid body having a top wall portion that detachably covers the opening, The lid body is formed with a lateral displacement prevention portion that receives the bottom wall portion and prevents the container body from displacing in a surface direction of the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward, the bottom wall portion is polygonal in plan view, the lateral displacement prevention portion is a recess corresponding to the shape of the bottom wall portion, The lateral displacement prevention portion has an expanded recess that expands outward at the position of a corner of the bottom wall portion when the container body is placed on the lid with the inner surface of the lid facing upward. The present invention further has the following aspects. <1> a container body having a bottom wall portion and a side wall portion rising from a peripheral edge of the bottom wall portion, and having an opening at an upper end; a lid body having a top wall portion that detachably covers the opening, A resin container in which the lid body is formed with a lateral slippage prevention portion that receives the bottom wall portion and prevents the container body from slipping in the surface direction of the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward. <2> a first fitting portion is formed on the outer surface of the container body, and a second fitting portion is formed on the inner surface of the lid body; When the container body is placed on the lid body with the inner surface of the lid body facing upward, the bottom wall portion and the first fitting portion and the second fitting portion of the lid body are fitted together to prevent the container body from shifting in a direction away from the lid body. <1> The resin container according to claim 1. <3> When the container body is placed on the lid with the inner surface of the lid facing upward, at least a part of the bottom wall and the top wall are separated to form a space. <1> or <2> The resin container according to claim 1. <4> The container body is formed of a thermoplastic foamed resin or a thermoplastic non-foamed resin having an expansion ratio of less than 6 times. <1> ~ <3> The resin container according to any one of the preceding items. <5> the lid body has a spacer at the position of the bottom wall portion that protrudes toward the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward, <1> ~ <4> The resin container according to any one of the preceding items. <6> The lateral displacement prevention portion is a recess corresponding to the shape of the bottom wall portion. <1> ~ <5> The resin container according to any one of the preceding items. <7> the bottom wall portion is polygonal in plan view, the lateral displacement prevention portion is a recess corresponding to the shape of the bottom wall portion, The lateral displacement prevention portion has an expanded recess portion that expands outward at a corner of the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward. <1> ~ <5> The resin container according to any one of the preceding items. <8> The container body is formed of a filler-containing polypropylene resin. <1> ~ <7> The resin container according to any one of the preceding items. <9> For cooked foods, <1> ~ <8> The resin container according to any one of the preceding items. [Effects of the Invention]

[0007] The resin container of the present invention can save space during transportation or storage, and can be easily handled even when it contains cooked food. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a resin container according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a bottom view of the resin container according to the first embodiment of the present invention. [Figure 3] 1 is a plan view of a resin container according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view taken along line IV-IV in FIG. [Figure 5] 1A to 1C are cross-sectional schematic views showing a method of using the resin container according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a fitting structure. [Figure 7] FIG. 2 is a cross-sectional view showing an example of a fitting structure. [Figure 8] FIG. 2 is a cross-sectional view showing an example of a fitting structure. [Figure 9] FIG. 2 is a cross-sectional view showing an example of a fitting structure. [Figure 10] FIG. 10 is a perspective view of a resin container according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a perspective view of a resin container according to a second embodiment of the present invention. [Figure 12] FIG. 10 is a perspective view of a resin container according to a third embodiment of the present invention. [Figure 13] FIG. 10 is a perspective view of a resin container according to a third embodiment of the present invention. [Figure 14]FIG. 10 is a perspective view of a container body according to another embodiment of the present invention. [Figure 15] FIG. 10 is a perspective view of a container body according to another embodiment of the present invention. [Figure 16] FIG. 10 is a perspective view of a container body according to another embodiment of the present invention. [Figure 17] FIG. 10 is a perspective view of a container body according to another embodiment of the present invention. [Figure 18] 10A and 10B are plan views showing examples of spacers for the lid body. [Figure 19] 10A and 10B are plan views showing examples of spacers for the lid body. DETAILED DESCRIPTION OF THE INVENTION

[0009] The resin container of the present invention has a container body having an opening at the top end and a lid for closing the opening. Hereinafter, the resin container of the present invention will be described with reference to embodiments.

[0010] (First embodiment) A resin container according to a first embodiment of the present invention will be described. 1 has a container body 10 having an opening 11 at the top end, and a lid body 20 that is detachable from the container body 10. The lid body 20 closes the opening 11 when attached to the container body 10.

[0011] As shown in FIGS. 1 and 2, the container body 10 has a bottom wall portion 12 that is rectangular in plan view, and a side wall portion 14 that rises from the periphery of the bottom wall portion 12 and surrounds the opening portion 11. The bottom wall portion 12 has a bottom step portion 13 that is convex toward the opening 11 and concave in the opposite direction to the opening 11 in a region inside the periphery and including the center of the bottom wall portion 12. The side wall 14 includes a first side wall piece 14a rising upward from the periphery of the bottom wall 12, a second side wall piece 14b extending outward from the upper end of the first side wall piece 14a, a third side wall piece 14c rising upward from the outer edge of the second side wall piece 14b, a fourth side wall piece 14d rising further upward from the upper end of the third side wall piece 14c, a fifth side wall piece 14e extending outward from the upper end of the fourth side wall piece 14d, and a sixth side wall piece 14f rising upward from the outer edge of the fifth side wall piece 14e. In this embodiment, the fourth side wall piece 14d expands in diameter toward the opening 11 to a greater extent than the third side wall piece 14c. The container body 10 has a body flange portion 16 that projects outward from the upper end of the side wall portion 14 (that is, the upper end of the sixth side wall piece 14f).

[0012] The bottom wall portion 12 is generally square in bottom view, with the four corners rounded off in an arc shape. First fitting portions 15 are formed on the outer surface of the third side wall piece 14c at the positions of the four corners.

[0013] As shown in FIGS. 1 and 3, the lid 20 has a top wall portion 21 that is rectangular in plan view, and a lid flange portion 26 that projects outward from the outer edge of the top wall portion 21. The cover flange 26 projects outward from the outer edge of the top wall 21, then bends toward the top wall 21, and then projects outward again. At each of the four corners of the lid flange 26, a tab 29 is formed that protrudes outward. The lid 20 has a lateral displacement prevention portion 22 that is convex on one surface of the top wall 21 and concave on the other surface of the top wall 21. The lateral displacement prevention portion 22 is roughly square in plan view, and has expanded recesses 24 that further expand outward in an arc shape at the four corners. The lateral displacement prevention portion 22 is sized to receive the bottom wall 12 when the inner surface of the lid 20 is facing upward and the container body 10 is placed on the lid 20. That is, in this embodiment, the lateral displacement prevention portion 22 is a "recess that corresponds to the shape of the bottom wall portion." In this document, the "inner surface" refers to the surface facing the inside of the resin container 1 (i.e., the space for storing food) when the opening 11 of the container body 10 is closed with the lid 20. The lateral displacement prevention portion 22 has a top surface step 23 that is convex on one side of the top wall portion 21 and concave on the other side, in an area including the center of the top wall portion 21. The top surface step 23 is convex in the direction away from the opening 11 when the opening 11 is closed by the lid 20. The lateral displacement prevention portion 22 has a protruding portion 27 that protrudes outward from the lateral displacement prevention portion 22 between the expanded recesses 24 at the open end thereof. The lateral displacement prevention portion 22 has a holding wall portion 22a that runs around the lid flange portion 26 near the lid flange portion 26. The retaining wall portion 22 a has a second fitting portion 25 on its inner surface at the position of the expanded recess 24 .

[0014] The size of the container body 10 can be determined appropriately taking into consideration the intended use. If the resin container 1 is for cooked food, it is, for example, 10 to 25 cm long x 10 to 25 cm wide x 3 to 10 cm high. The wall thickness of the container body 10 is, for example, preferably 0.1 to 3.0 mm, more preferably 0.2 to 2.0 mm. The wall thickness of the container body 10 is an average value obtained by measuring at any 10 points with a micrometer.

[0015] The size of the lid body 20 is determined appropriately according to the size of the container body 10 .

[0016] The first fitting portion 15 and the second fitting portion 25 may have any shape as long as they can be fitted together. In this embodiment, the first fitting portion 15 is a convex ridge that protrudes outward from the side wall portion 14, and is a rectangle with its longitudinal direction aligned with the circumferential direction of the side wall portion 14 in a front view. In addition, the width of the first fitting portion 15 gradually narrows in the protruding direction. The second fitting portion 25 is a concave ridge that extends from the inner surface of the lid 20 to the outer surface, and has a shape that corresponds to the shape of the first fitting portion 15.

[0017] In this embodiment, the outer surface shape of the bottom surface step portion 13 is sized and shaped to be able to accommodate the outer surface shape of the top surface step portion 23 .

[0018] The container body 10 is a molded product of a thermoplastic resin composition. The container body 10 may be, for example, a thermoformed product of a thermoplastic resin sheet or an injection-molded product of a thermoplastic resin. The container body 10 may be made of a thermoplastic non-foamed resin, a thermoplastic foamed resin, or a laminate of these. When the container body 10 is made of a thermoplastic non-foamed resin, the thickness of the container body 10 is preferably 0.1 to 1.0 mm, and more preferably 0.2 to 0.8 mm. When the container body 10 is made of a thermoplastic foam resin, the thickness of the container body 10 is preferably 0.5 to 3.0 mm, and more preferably 1.0 to 2.0 mm. If the wall thickness of the container body 10 is equal to or greater than the above lower limit, the rigidity of the container body 10 can be further increased. If the wall thickness of the container body 10 is equal to or less than the above upper limit, further space saving can be achieved during transportation or storage. When the container body 10 is a thermoplastic foamed resin, the expansion ratio is not particularly limited, but is preferably more than 1 and not more than 10, more preferably more than 1 and not more than 8, even more preferably more than 1 and not more than 6, particularly preferably more than 1 and not more than 5, and most preferably more than 1 and not more than 3. If the expansion ratio is above the lower limit, the heat insulating properties of the container body 10 can be improved. If the expansion ratio is not more than the upper limit, the bulk of the container body 10 does not become excessively large, thereby saving space during transportation and storage. The expansion ratio is determined by the apparent density (g / cm) of the thermoplastic foam resin. 3 The apparent density can be measured according to JIS K7222:2005 "Foam plastics and rubber - Determination of apparent density."

[0019] Examples of the thermoplastic resin include polyolefin resin, polyester resin, and polystyrene resin.

[0020] Examples of polyolefin resins include polyethylene or polypropylene, which are homopolymers of olefin monomers such as ethylene and propylene; copolymers of olefin monomers; and copolymers of olefin monomers with vinyl monomers polymerizable therewith, with an olefin monomer as the main component. The term "main component" refers to the polymer with the largest molar ratio among the monomers used. Polyolefin resins may be used alone or in combination of two or more types. The polyolefin resin may be a polyolefin resin derived from petrochemicals or a plant-derived polyolefin resin. Examples of plant-derived resins include polymers derived from plant materials such as sugarcane and corn. "Derived from plant materials" includes polymers synthesized or extracted from plant materials. Furthermore, "derived from plant materials" includes polymers obtained by polymerizing monomers synthesized or extracted from plant materials. "Monomers synthesized or extracted from plant materials" includes monomers synthesized using compounds synthesized or extracted from plant materials. Plant-derived resins include those in which some of the monomers are "derived from plant materials." Examples of plant-derived polyolefin resins include polyethylene obtained by polymerizing ethylene obtained by the dehydration reaction of bioethanol.

[0021] Examples of polyester resins include polyethylene terephthalate and polyethylene furanoate. The polyester resin may be a petrochemical-derived polyester resin or a plant-derived polyester resin. Examples of plant-derived polyester resins include polyethylene terephthalate synthesized from ethylene glycol, which is synthesized from ethylene obtained by dehydrating plant-derived ethanol, and paraxylene, which is obtained by dehydrating plant-derived isobutanol, and terephthalic acid, which is synthesized from the paraxylene.

[0022] Examples of polystyrene-based resins include homopolymers of styrene-based monomers such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene, ethylstyrene, i-propylstyrene, dimethylstyrene, and bromostyrene, or copolymers thereof; copolymers of styrene-based monomers and vinyl monomers polymerizable therewith, with styrene-based monomers as the main component (50% by mass or more); copolymers of styrene-based monomers and rubber components such as butadiene; and so-called high impact polystyrene resins (HIPS), which are mixtures or polymers of homopolymers of styrene-based monomers or copolymers thereof, or copolymers of styrene-based monomers and vinyl monomers with diene-based rubber polymers.

[0023] The container body 10 may contain additives other than the thermoplastic resin, such as fillers, foaming agents, foam nucleating agents, surfactants, and pigments. In particular, it is preferable that the container body 10 contains a filler. Examples of fillers include calcium carbonate, talc, silica, clay, alumina, mica, titanium oxide, glass beads, glass balloons, carbon fiber, glass fiber, carbon black, and metal powder. By containing these fillers, the container body 10 can maintain good rigidity even when the temperature of the contents increases. The content of the filler is preferably 1 to 150 parts by mass, more preferably 25 to 70 parts by mass, relative to 100 parts by mass of the thermoplastic resin.

[0024] A filler-containing polypropylene resin, and a filler-containing non-foamed polypropylene resin, is preferred as the material for the container body 10. If the container body 10 is made of such a material, the thickness of the container body 10 can be reduced, the bulk can be reduced, and the rigidity can be increased.

[0025] The lid 20 is a molded product of a thermoplastic non-foamed resin. The lid 20 may be, for example, a thermoformed product of a thermoplastic resin sheet or an injection-molded product of a thermoplastic resin. The lid 20 may be made of a thermoplastic non-foamed resin, a thermoplastic foamed resin, or a laminate of these. The thickness of the lid body 20 is the same as the thickness of the container body 10 . Examples of the thermoplastic resin used for the lid body 20 include the same resin as the thermoplastic resin used for the container body 10. Among them, since the contents inside the resin container 1 can be visually observed, the lid body 20 is preferably made of a transparent thermoplastic non-foamed resin, such as oriented polystyrene, polyethylene terephthalate, or polypropylene.

[0026] The material of the lid body 20 is preferably harder than the material of the container body 10. If the material of the lid body 20 is harder than the material of the container body 10, the lid body 20 will be even less likely to come off when attached to the container body 10. In this document, the larger the value measured by JIS K6253-3:2012 "Durometer hardness", the "harder" is defined as the material.

[0027] A method for manufacturing the resin container 1 will be described. A raw sheet for a container body and a raw sheet for a lid are obtained, which are a thermoplastic foamed resin sheet, a thermoplastic non-foamed resin sheet, or a laminated sheet thereof. The raw sheet for the container body is manufactured by melting and kneading the material for the container body 10 in an extruder, extruding it from a die (for example, a T-die or a circular die) at the tip of the extruder, and cooling it to form a raw sheet. The raw sheet for the lid is manufactured by melting and kneading the material for the lid 20 in an extruder, extruding it from a die (for example, a T-die or a circular die) at the tip of the extruder, and cooling it to form a raw sheet.

[0028] Next, the obtained raw sheet is heated to soften it, and the softened raw sheet is sandwiched between a mold to form the container body 10 or the lid body 20.

[0029] Next, an example of how to use the resin container 1 will be described with reference to FIGS. The opening 11 of the container body 10 is faced upward, the contents are placed inside the container body 10, and the top step 23 is turned upward to close the opening 11 with the lid 20, completing the containerized item (FIG. 4). At this time, the lid flange 26 is fitted inside the body flange 16 (internal fitting type). This makes it difficult for the lid 20 to come off the container body 10. When the lid 20 covers the opening 11, the top step 23 of the lid 20 is convex upward, and the bottom step 13 of the container body 10 is convex upward. In this embodiment, the bottom step 13 has a shape and size that can receive the top step 23, so when containerized articles are stacked one on top of the other, the top step 23 is inserted into the bottom step 13, preventing the upper and lower containerized articles from shifting sideways relative to each other.

[0030] The contents may be, for example, cooked foods distributed at room temperature, refrigerated, or frozen. Alternatively, the contents may be foods immediately after cooking. Examples of cooked foods include staple foods such as rice and pasta, various side dishes, and combinations thereof.

[0031] The contents of the container are heated in a microwave oven to the desired temperature. The lid 20 is removed from the container body 10. Next, the inner surface of the lid 20 is oriented vertically upward, and the inner surface of the lid 20 faces the outer surface of the bottom wall 12 of the container body 10. The container body 10 is placed on the lid 20. At this time, the four corners of the bottom wall 12 are positioned in the four expanded recesses 24, and the bottom wall 12 is inserted into the lateral displacement prevention portion 22. When the bottom wall 12 is inserted into the lateral displacement prevention portion 22, the second side wall piece 14b abuts against the upper surface of the protruding portion 27, and the container body 10 is supported by the protruding portion 27. This determines the distance between the outer surface of the bottom wall 12 and the top wall 21. In addition, the retaining wall portion 22a surrounds the third side wall piece 14c of the container body 10. As a result, the holding wall 22a restricts the movement of the container body 10, preventing the container body 10 from shifting in the planar direction (substantially horizontal direction) of the bottom wall 12. Furthermore, the first fitting portion 15 of the container body 10 enters the second fitting portion 25 of the lid 20, and the first fitting portion 15 and the second fitting portion 25 are fitted together. This prevents the container body 10 from shifting in the direction away from the lid 20 (substantially vertical direction) (FIG. 5). With the inner surface of the lid 20 facing upward and the container body 10 placed on top of it, the eater grips the resin container 1 with their hands against the lid 20 and eats the contents. At this time, because the bottom surface has a double structure of the bottom wall 12 and the top wall 21, the eater is less likely to feel the heat of the contents.

[0032] In the first embodiment, when the container body 10 is placed on the lid 20, the top surface step 23 and the bottom surface step 13 are convex in directions away from each other. As a result, the bottom wall 12 of the container body 10 and the top wall 21 of the lid 20 are separated to form a space. This separated space structure makes it difficult for the heat of the contents to be transmitted by the lid 20, making it less likely that the eater will feel the heat of the contents. In the first embodiment, the lateral slippage prevention portion 22 has the expansion recess 24, so that at the corners of the bottom wall 12 of the container body 10, the bottom wall 12 of the container body 10 and the top wall 21 of the lid 20 are separated to form a space, and the side wall 14 of the container body 10 and the expansion recess 24 of the lid 20 are also separated to form a space. Normally, when heating in a microwave oven, energy is concentrated at the corners, which can cause the corners to become higher in temperature than the center. Therefore, by providing the expansion recess 24, even if the corners of the container body 10 become excessively hot, the heat of the contents is less likely to be transmitted to the eater. It is preferable that at least a portion of the bottom wall 12 of the container body 10 and the top wall 21 of the lid 20 are separated to form a space. It is more preferable that the entire bottom wall 12 of the container body 10 and the top wall 21 of the lid 20 are separated to form a space. In addition, it is even more preferable that at least a portion of the side wall 14 of the container body 10 and the lid 20 are separated to form a space.

[0033] In the first embodiment, the mating structure is formed by a first mating portion 15 that is rectangular in front view and gradually narrows in width toward the protruding direction, and a second mating portion 25 that has a corresponding shape, but the mating structure may also be, for example, the mating structure shown in Figures 6 to 9. The fitting structure shown in Fig. 6 has a first fitting portion 15a having a convex shape formed on the outer surface of the third side wall piece 14c of the container body 10 and a second fitting portion 25a having a concave shape formed on the inner surface of the holding wall portion 22a of the lid 20. The width of the first fitting portion 15a gradually increases in the protruding direction. The width of the second fitting portion 25a gradually increases in the depth direction.

[0034] The fitting structure shown in Fig. 7 has a convex second fitting portion 25b formed on the inner surface of the holding wall portion 22a of the lid body 20 and a concave first fitting portion 15b formed on the outer surface of the third side wall piece 14c of the container body 10. The width of the second fitting portion 25b gradually increases in the protruding direction. The width of the first fitting portion 15b gradually increases in the depth direction.

[0035] The fitting structure of Fig. 8 has a first fitting portion 15c with a convex shape formed on the outer surface of the second side wall piece 14b of the container body 10 and a second fitting portion 25c with a concave shape formed on the inner surface of the protruding portion 27 of the lid 20. The width of the first fitting portion 15c gradually increases in the protruding direction. The width of the second fitting portion 25c gradually increases in the depth direction.

[0036] The fitting structure shown in Fig. 9 has a convex second fitting portion 25d formed on the inner surface of the protruding portion 27 of the lid 20 and a concave first fitting portion 15d formed on the outer surface of the second side wall piece 14b of the container body 10. The width of the second fitting portion 25d gradually increases in the protruding direction. The width of the first fitting portion 15d gradually increases in the depth direction.

[0037] By using the fitting structures shown in FIGS. 6 to 9, the fitting force between the first fitting portion and the second fitting portion becomes even stronger.

[0038] In the first embodiment, the first fitting portion 15 has a rectangular shape when viewed from the front, but the shape of the first fitting piece is not limited to this. The shape of the first fitting portion may be circular, such as a perfect circle or an ellipse, when viewed from the front, or polygonal, such as a triangle, a pentagon, a star, etc. Alternatively, the shape of the first fitting portion may be gourd-shaped or the like when viewed from the top.

[0039] (Second embodiment) A container according to a second embodiment of the present invention will now be described. The resin container 100 in FIG. 10 has a container body 110 and a lid body 120.

[0040] 10 and 11, the container body 110 has a bottom wall portion 112 that is substantially circular in plan view, and a side wall portion 114 that rises from the periphery of the bottom wall portion 112. The container body 110 has an opening 111 at its upper end, and a body flange portion 116 that protrudes outward from the upper end of the side wall portion 114 and surrounds the periphery of the opening 111. The bottom wall 112 has a bottom step 113 that is convex toward the opening 111 and concave in the opposite direction to the opening 111 on the inner side of its periphery in a region including the center of the bottom wall 112 .

[0041] As shown in FIGS. 10 and 11, the lid 120 has a top wall portion 121 that is substantially circular in plan view, and a lid flange portion 126 that projects outward from the outer edge of the top wall portion 121. The cover flange 126 projects outward from the outer edge of the top wall 121, then bends toward the top wall 121, and then projects outward again. The lid 120 has a lateral displacement prevention portion 122 that is convex on one surface of the top wall 121 and concave on the other surface of the top wall 121. The lateral displacement prevention portion 122 is substantially circular in plan view, and with the inner surface facing upward (FIG. 11), has a bottom surface 127 that is also circular in plan view, and side surfaces 122a that rise from the periphery of the bottom surface 127. The lateral displacement prevention portion 122 is sized to receive the bottom wall 112 when the inner surface of the lid 120 faces upward and the container body 110 is placed on the lid 120. That is, in this embodiment, the lateral displacement prevention portion 122 is a "recess corresponding to the shape of the bottom wall portion." The lid 120 has a top surface step 123 in a region including the center of the top wall 121, which is substantially circular in plan view and is convex on one side and concave on the other side of the top wall 121. The top surface step 123 is convex in the direction away from the opening 111 when the opening 111 is closed by the lid 120 (FIG. 10).

[0042] In this embodiment, the outer surface shape of the bottom surface step portion 113 is sized and shaped to be able to accommodate the outer surface shape of the top surface step portion 123 .

[0043] The material of the container body 110 is the same as the material of the container body 10 in the first embodiment. The size of the container body 110 can be determined appropriately taking into consideration the intended use. If the resin container 100 is for cooked food, the opening 111 has an opening diameter of 10 to 25 cm and a height of 3 to 10 cm, for example. The thickness of the container body 110 is the same as the thickness of the container body 10 in the first embodiment.

[0044] The material of the lid 120 is the same as the material of the lid 20 in the first embodiment. The size of the lid 120 can be determined appropriately depending on the size of the container body 110 . The thickness of the lid 120 is the same as the thickness of the lid 20 in the first embodiment.

[0045] Next, an example of how to use the resin container 100 will be described. Contents are placed in container body 110, and lid 120 is attached to container body 110 to complete the containerized item (FIG. 10). At this time, lid flange 126 is fitted inside body flange 116 (internal fitting type). This makes it difficult for lid 120 to come off container body 110. When the opening 111 is covered with the lid 120 (FIG. 10), the top surface step 123 of the lid 120 is convex upward, and the bottom surface step 113 of the container body 110 is convex upward. In this embodiment, the bottom surface step 113 has a shape and size that can receive the top surface step 123, so when containerized articles are stacked one on top of the other, the top surface step 123 is inserted into the bottom surface step 113, preventing the upper and lower containerized articles from shifting sideways relative to each other.

[0046] The contents are the same as those in the first embodiment.

[0047] The contents of the container are heated in a microwave oven to a desired temperature. The lid 120 is removed from the container body 110. Next, the inner surface of the lid 120 is oriented vertically upward, and the inner surface of the lid 120 faces the outer surface of the bottom wall 112 of the container body 110, and the container body 110 is placed on the lid 120. At this time, the bottom wall 112 is inserted into the lateral displacement prevention portion 122. When the bottom wall 112 is inserted into the lateral displacement prevention portion 122, the outer portion of the bottom step 113 of the bottom wall 112 abuts and rests on the upper surface of the bottom surface 127. This forms a space between the bottom step 113 and the top step 123. In addition, the side surface 122a of the lateral displacement prevention portion 122 of the lid 120 surrounds the side wall 114 of the container body 110. As a result, the side surface 122a restricts the movement of the container body 110, and prevents the container body 110 from shifting in the plane direction of the bottom wall portion 112 (substantially horizontal direction). Furthermore, if the lateral displacement prevention portion 122 is of a size such that the side surface 122a presses against the side wall portion 114 of the container body 110 when the lateral displacement prevention portion 122 receives the bottom wall portion 112, the side surface 122a functions to prevent the container body 110 from shifting in a direction away from the lid body 120. With the inner surface of the lid body 120 facing upward and the container body 110 placed on top of it (FIG. 11), the eater places their hand on the lid body 120 to grip the resin container 100 and eat the contents.

[0048] The second embodiment may have a fitting structure similar to that of the first embodiment. For example, a first fitting portion similar to that of the first embodiment may be formed on the side wall portion 114 or the bottom wall portion 112, and a second fitting portion similar to that of the first embodiment may be formed on the side surface 122a or the bottom surface 127. By having the fitting structure, the resin container 100 can prevent the container body 110 and the lid body 120 from shifting in directions away from each other.

[0049] (Third embodiment) A container according to a third embodiment of the present invention will now be described. The resin container 200 in FIG. 12 has a container body 210 and a lid body 220.

[0050] 12 and 13, the container body 210 has a bottom wall portion 212 that is substantially circular in plan view, and a side wall portion 214 that rises from the periphery of the bottom wall portion 212 and then further expands in diameter. The container body 210 has an opening 211 at its upper end, and a body flange portion 216 that protrudes outward from the upper end of the side wall portion 214 and goes around the periphery of the opening 211. The bottom wall portion 212 has a bottom step portion 213 that is convex toward the opening 211 and concave in the opposite direction to the opening 211 on the inner side of its periphery in a region including the center of the bottom wall portion 212 .

[0051] As shown in Figures 12 and 13, the lid body 220 has a top wall portion 221 that is approximately circular in plan view, a lid body flange portion 226 that protrudes outward from the outer edge of the top wall portion 221, and a peripheral wall portion 228 that extends inward (away from the top wall portion 221) from the peripheral edge of the lid body flange portion 226. The lid 220 has a lateral displacement prevention portion 222 that is convex on one surface of the top wall 221 and concave on the other surface of the top wall 221. The lateral displacement prevention portion 222 is substantially circular in plan view, and with the inner surface facing upward ( FIG. 13 ), has a bottom surface 227 that is also circular in plan view, and side surfaces 222a that rise from the periphery of the bottom surface 227. The lateral displacement prevention portion 222 is sized to receive the bottom wall 212 when the inner surface of the lid 220 faces upward and the container body 210 is placed on the lid 220. That is, in this embodiment, the lateral displacement prevention portion 222 is a "recess corresponding to the shape of the bottom wall portion." The lid 220 has a top surface step 223 in a region including the center of the top wall 221, which is substantially circular in plan view and is convex on one side and concave on the other side of the top wall 221. The top surface step 223 convex in the direction away from the opening 211 when the opening 211 is closed by the lid 220 (FIG. 12).

[0052] In this embodiment, the outer surface shape of the bottom surface step portion 213 is sized and shaped to be able to accommodate the outer surface shape of the top surface step portion 223 .

[0053] The material of the container body 210 is the same as the material of the container body 10 in the first embodiment. The size of the container body 210 can be determined appropriately taking into consideration the intended use. If the resin container 200 is for cooked food, the opening 211 has an opening diameter of 10 to 25 cm and a height of 3 to 10 cm, for example. The thickness of the container body 210 is the same as the thickness of the container body 10 in the first embodiment.

[0054] The material of the lid 220 is the same as the material of the lid 20 in the first embodiment. The size of the lid 220 can be determined appropriately depending on the size of the container body 210 . The thickness of the lid 220 is the same as the thickness of the lid 20 in the first embodiment.

[0055] Next, an example of how to use the resin container 200 will be described. Contents are placed in container body 210, and lid 220 is attached to container body 210 to complete the containerized item (FIG. 12). At this time, lid flange 226 is placed on body flange 216, and peripheral wall 228 is positioned outside body flange 216, and body flange 216 is fitted into lid flange 226 (external fitting type). This makes it difficult for lid 220 to come off container body 210. When the opening 211 is covered with the lid 220 (FIG. 12), the top surface step 223 of the lid 220 is convex upward, and the bottom surface step 213 of the container body 210 is convex upward. In this embodiment, the bottom surface step 213 has a shape and size that can receive the top surface step 223, so when containerized articles are stacked one on top of the other, the top surface step 223 is inserted into the bottom surface step 213, preventing the upper and lower containerized articles from shifting sideways relative to each other.

[0056] The contents are the same as those in the first embodiment.

[0057] The containered items are heated in a microwave oven to a desired temperature. The lid 220 is removed from the container body 210. Next, the inner surface of the lid 220 is oriented vertically upward, and the inner surface of the lid 220 faces the outer surface of the bottom wall 212 of the container body 210, and the container body 210 is placed on the lid 220. At this time, the bottom wall 212 is inserted into the lateral displacement prevention portion 222. When the bottom wall 212 is inserted into the lateral displacement prevention portion 222, the outer portion of the bottom step 213 of the bottom wall 212 abuts and rests on the upper surface of the bottom surface 227. This forms a space between the bottom step 213 and the top step 223. In addition, the side surface 222a of the lateral displacement prevention portion 222 of the lid 220 surrounds the side wall 214 of the container body 210. As a result, the side surface 222a restricts the movement of the container body 210, and prevents the container body 210 from shifting in the plane direction of the bottom wall portion 212 (substantially horizontal direction). Furthermore, if the lateral displacement prevention portion 222 is of a size such that the side surface 222a presses against the side wall portion 214 of the container body 210 when the lateral displacement prevention portion 222 receives the bottom wall portion 212, the side surface 222a functions to prevent the container body 210 from shifting in a direction away from the lid body 220. With the inner surface of the lid body 220 facing upward and the container body 210 placed on top of it (FIG. 13), the eater places their hand on the lid body 220 to grip the resin container 200 and eat the contents.

[0058] The third embodiment may have a fitting structure similar to that of the first embodiment. For example, a first fitting portion similar to that of the first embodiment may be formed on the side wall portion 214 or the bottom wall portion 212, and a second fitting portion similar to that of the first embodiment may be formed on the side surface 222a or the bottom surface 227. By having the fitting structure, the resin container 200 can prevent the container body 210 and the lid body 220 from shifting in directions away from each other.

[0059] (Other embodiments) The present invention is not limited to the above-described embodiments. Although the first embodiment is an internal fitting type, the present invention is not limited to this, and an external fitting type may also be used.

[0060] In the first embodiment, the first fitting portion is provided in the lateral displacement prevention portion, but the present invention is not limited thereto, and the first fitting portion may be provided in a position other than the lateral displacement prevention portion. Furthermore, the resin container of the present invention may not have both or either of the first fitting portion and the second fitting portion. However, from the viewpoint of preventing the container body from shifting away from the lid during consumption, it is preferable that the resin container have a fitting structure.

[0061] The container body of the first embodiment has a square shape in plan view, and the container bodies of the second and third embodiments have a perfect circle shape in plan view, but the present invention is not limited to this. The shape of the container body can be any shape in plan view, including circles such as perfect circles and ellipses, and polygons such as triangles, squares, and pentagons. For example, the container body of the present invention may have, as in the container body 310 of Figure 14, a rectangular bottom wall portion 312 with one longitudinal direction in a plan view, a side wall portion 314 rising from the periphery of the bottom wall portion 312, and a body flange portion 316 protruding outward at the upper end of the side wall portion 314. For example, the container body of the present invention may have a bottom wall portion 322 that is a regular octagon when viewed from above, a side wall portion 324 that rises from the periphery of the bottom wall portion 322, and a body flange portion 326 that protrudes outward at the upper end of the side wall portion 324, as in the container body 320 of Figure 15. Alternatively, the container body of the present invention may have a bottom wall portion 332 that is oval in plan view, a side wall portion 334 that rises from the periphery of the bottom wall portion 332, and a body flange portion 336 that protrudes outward at the upper end of the side wall portion 334, as in the container body 330 of Figure 16. Alternatively, the container body of the present invention may have a so-called "gourd-shaped" bottom wall portion 342 in a planar view, a side wall portion 344 rising from the periphery of the bottom wall portion 342, and a body flange portion 346 protruding outward at the upper end of the side wall portion 344, as in the container body 340 of Figure 17. In this way, the shape of the container body can be any shape in plan view, including circles such as perfect circles, ovals, and ellipses, and polygons such as triangles, rectangles, and pentagons. The lid of the present invention can be appropriately determined depending on the shape of the container body.

[0062] The lid of the container of the present invention may have a spacer that protrudes from the lid toward the bottom wall when the container body is placed on the inner surface of the lid. When the container-filled item is heated, the container body softens. When the container body softens, the bottom wall may bulge downward due to the weight of the contents. When the bottom wall bulges downward, when the inner surface of the lid is facing upward and the container body is placed on the lid, the contact area between the bottom wall and the lid increases, making it easier for the heat of the contents to be transferred to the eater. Therefore, by having the lid have a spacer that protrudes from the inner surface, when the inner surface of the lid is facing upward and the container body is placed on the lid, the bottom wall can be supported by the spacer, reducing the area of contact between the bottom wall and the lid. Furthermore, the presence of the spacer makes it easier to separate at least a portion of the bottom wall from the lid, forming a space, which further reduces the transfer of heat from the contents to the eater. The height of the spacer (the distance from the base end to the tip end of the spacer) is, for example, preferably 1 to 10 mm, more preferably 3 to 8 mm. The size (size in plan view), shape, number, arrangement, etc. of the spacers can be determined appropriately taking into consideration the size, material, etc. of the container body. In addition, the spacer may not only protrude from the lid body toward the bottom wall of the container body, but also protrude from the lid body toward the side wall of the container body, making it easier to separate at least a portion of the side wall of the container body from the lid body and form a space.

[0063] The shape of the spacer is not particularly limited, and various shapes can be adopted. Examples of spacer shapes are shown in FIGS. The spacer 510 in FIG. 18(a) has a cross shape in plan view. The spacer 512 in FIG. 18(b) has a frame shape with a rectangular outer edge in plan view. The spacer 514 in FIG. 18(c) is a ridge extending in any direction. The spacer 516 in FIG. 18(d) is made of a single circular ring. 18(e) is annular and smaller than the spacer 516. The four spacers 518 are located at the vertices of an imaginary square. 18(f) is a V-shaped convex stripe in plan view. Two spacers 519 are arranged side by side with their vertices facing each other.

[0064] 19(a) is a convex strip extending in any direction in plan view. The three spacers 520 are spaced apart from each other in the width direction and are arranged in parallel. 19(b) is a rectangular frame shape that is smaller than the spacer 512. The four spacers 522 are located at the vertices of an imaginary rectangle. 19(c), in plan view, three ridges extending in any direction are spaced apart in the width direction and aligned parallel to each other, and three ridges perpendicular to these ridges are spaced apart in the width direction and aligned parallel to each other. The spacer 524 has a so-called grid shape. A spacer 526 in FIG. 19(d) is a combination of an annular convex portion and a convex strip that overlaps the diameter inside the annulus in plan view. The spacer 528 in FIG. 19(e) is made up of ridges that are intermittently positioned on two concentric circles. The position of the spacers on the bottom wall is not particularly limited, but it is preferable that each spacer is positioned so as to overlap the center of the bottom wall or so as to surround the center of the bottom wall.

[0065] In the first to third embodiments, the lateral displacement prevention portion is a recess that receives the bottom wall portion, but the present invention is not limited to this. For example, the lateral displacement prevention portion may be a ridge that surrounds the periphery of the bottom wall portion of the container body when the container body is placed on the inner surface of the lid. This ridge may be a continuous ridge that goes around the bottom wall portion, or may be an intermittent ridge. [Explanation of symbols]

[0066] 1, 100, 200 Resin container 10, 110, 210, 310, 320, 330, 340 Container body 11, 111, 211 openings 12, 112, 212, 312, 322, 332, 342 Bottom wall 14, 114, 214, 314, 324, 334, 344 Side wall 15, 15a, 15b, 15c, 15d First fitting portion 20, 120, 220 lid 21, 121, 221 ceiling wall 22, 122, 222 Side slip prevention part 24 Expanded recess 25, 25a, 25b, 25c, 25d Second fitting portion 510, 512, 514, 516, 518, 519, 520, 522, 524, 526, 528 Spacers

Claims

1. a container body having a bottom wall portion and a side wall portion rising from a peripheral edge of the bottom wall portion, and having an opening at an upper end; a lid body having a top wall portion that detachably covers the opening, The lid body is formed with a lateral displacement prevention portion that receives the bottom wall portion and prevents the container body from displacing in a surface direction of the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward, the bottom wall portion is polygonal in plan view, the lateral displacement prevention portion is a recess corresponding to the shape of the bottom wall portion, The resin container has an expanded recess that expands outward at a corner of the bottom wall when the container body is placed on the lid with the inner surface of the lid facing upward.

2. The resin container according to claim 1 , wherein when the container body is placed on the lid with the inner surface of the lid facing upward, at least a portion of the bottom wall and the top wall are separated to form a space.

3. 3. The resin container according to claim 1, wherein the container body is formed of a thermoplastic foamed resin or a thermoplastic non-foamed resin having an expansion ratio of less than 6 times.

4. The resin container according to any one of claims 1 to 3, wherein the lid body has a spacer at the position of the bottom wall portion that protrudes toward the bottom wall portion when the container body is placed on the lid body with the inner surface of the lid body facing upward.

5. The resin container according to any one of claims 1 to 4, wherein the container body is formed from a polypropylene-based resin containing a filler.

6. The resin container according to any one of claims 1 to 5, which is for cooked food.

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