JP7296187B2 - food packaging container - Google Patents

Description

TECHNICAL FIELD The present invention relates to a food packaging container for containing and selling food such as boxed lunches at convenience stores and the like.

2. Description of the Related Art Conventionally, in convenience stores and the like, food packaging containers for containing foods such as box lunches as contents include a container body configured to be able to contain food, etc., and a detachably attached to the opening of the container body. and a shrink film covering the container body and the lid with the lid attached to the opening of the container body (that is, with the contents accommodated).

In such a container, from the viewpoint of preventing leakage of moisture from the contents, an inner-fitting container is used in which the lid body is fitted into the inner periphery of the opening of the container body. Moreover, when heating the contents, the container containing the contents may be placed in a heating device such as a microwave oven, and the entire container may be heated. In this case, the air inside the container expands as it is heated, increasing the pressure inside the container (internal pressure). , the internal pressure becomes even higher. In such a state, the lid may unintentionally come off from the container body due to the internal pressure during or after heating, or the container itself may expand and deform. Such a problem is particularly conspicuous in inner-fitting containers.

Therefore, a container has been proposed in which a hole is formed for discharging water vapor and the like generated during heating to the outside of the container. For example, Patent Document 1 describes a microwave oven in which a U-shaped notch is formed in the center of a lid that fits inside the opening of a container body to form a vent for letting steam escape during rice cooking. A rice cooking container is disclosed. Further, Patent Document 2 discloses a microwave heated food container in which a large number (8 to 1000) of pores having a diameter of 0.5 mm or less are formed in the vicinity of the center of a lid that fits with the opening of the container body. ing.

JP 2012-50672 A JP 2017-81599 A

According to the containers disclosed in Patent Documents 1 and 2, etc., the water vapor generated during heating can be discharged through the hole formed in the lid, and the inner pressure of the lid during or after heating can It was possible to effectively prevent the body from unintentionally coming off the container body and the container itself and the lid from being deformed.

However, the intrusion of foreign matter from the hole formed in the lid occurs even if it is a cut disclosed in Patent Document 1 or a pore with a diameter of 0.5 mm or less as disclosed in Patent Document 2. Moreover, liquid leakage from the contents could occur through the hole. In addition, the formation of the hole requires a separate drilling process after forming the lid body by vacuum forming or the like, which also poses a problem in terms of productivity.

The present invention has been made in view of the above-mentioned problems of the background art, and the object thereof is to effectively release the steam generated when the contents are heated to the outside of the container, thereby increasing the internal pressure of the container. To provide a highly productive food packaging container that can suppress the intrusion of foreign matter into the container and the leakage of liquid from the contents to the outside of the container. be.

In order to achieve the above object, the present invention provides food packaging containers as described in the following [1] to [8].
[1] A food packaging container comprising a container body and a lid body that fits inside the container body,
The container body includes a bottom portion, a side wall portion rising from the bottom portion, a body fitting portion formed at an inner opening end of the side wall portion, and an upper edge of the body fitting portion formed outwardly. and a main body flange,
The lid includes a top plate portion, a lid fitting portion that hangs down from the periphery of the top plate portion and fits inside the body fitting portion of the container body, and overlaps the body flange portion when the lid is closed. a lid flange portion formed on the upper edge of the lid fitting portion;
A concave groove for constructing a passage for discharging water vapor or the like generated in the container to the outside of the container is formed in the lid body fitting portion and/or the main body fitting portion,
The plane view angle (∠AZB) formed by the inlet (A) for water vapor, etc., the outlet (B) for water vapor, etc. in the concave groove, and the center (Z) of the lid is 50 degrees or more. A food packaging container, characterized by:
[2] The food packaging container according to [1], wherein 3 to 10 passages are formed at different positions in the circumferential direction of the container.
[3] The ratio (s/S) of the total opening area (s) of the grooves to the area (S) of the fitting surfaces of the lid body fitting part and the body fitting part is 0.2 to 0. .6, the food packaging container according to the above [1] or [2].
[4] The food packaging container according to any one of [1] to [3], wherein the width of the opening of the concave groove is 2 to 5 mm.
[5] The food packaging container according to any one of [1] to [4] above, wherein the passage has a total passage volume (v) of 1 to 5 cm ³ .
[6] The above [ 1] The food packaging container according to any one of [5].
[7] The food packaging container according to any one of [1] to [6] above, wherein the lid flange portion is knurled.
[8] The food packaging container according to any one of [1] to [7], wherein the food packaging container is substantially circular in plan view.

According to the food packaging container according to the present invention, when the lid is normally closed, the lid body fitting portion of the lid body is fitted to the main body fitting portion of the container body by internal fitting to be in a closed state. Therefore, it is possible to effectively prevent foreign matter from entering the container. In addition, the concave groove formed in the lid body fitting portion and/or the main body fitting portion for constructing a passage for discharging water vapor generated in the container to the outside of the container, which will be described later, serves as an inlet for the water vapor. Since the plane view angle (∠AZB) formed by (A), the center (Z) of the lid, and the outlet (B) for water vapor or the like is 50 degrees or more, when the container is tilted Also, it is possible to effectively prevent the contents from leaking out of the container through the concave groove.
On the other hand, when the stored contents are heated, water vapor or the like generated by the heating of the contents smoothly flows out through the concave grooves formed in the lid fitting portion and/or the body fitting portion. It is possible to effectively prevent the lid from being detached from the container body or the container itself or the lid from being deformed due to the internal pressure. In addition, since the concave grooves that achieve the above functions and effects can be formed during molding of the lid body or the container body, the productivity is also excellent.

BRIEF DESCRIPTION OF THE DRAWINGS It is the perspective view which showed the lid open state of one Embodiment of the food packaging container which concerns on this invention. 1 is a front view showing part of an embodiment of a lid of a food packaging container according to the present invention; FIG. 1 is an end view showing a part of a lid closed state of an embodiment of a food packaging container according to the present invention; FIG. Conceptually, the measurement method of the plan view angle (∠AZB) formed by the inlet (A) for water vapor and the like, the outlet (B) for water vapor and the like in the concave groove of the present invention, and the center (Z) of the lid body 1 is a perspective view shown in FIG. Conceptually, the measurement method of the plan view angle (∠AZB) formed by the inlet (A) for water vapor and the like, the outlet (B) for water vapor and the like in the concave groove of the present invention, and the center (Z) of the lid body 1 is a perspective view shown in FIG. 1 is a front view conceptually showing a state in which a food packaging container according to the present invention is tilted; FIG. 1 is a front view conceptually showing a state in which a food packaging container according to the present invention is tilted; FIG. FIG. 2 is a front view conceptually showing the shapes of various recessed grooves formed in the lid fitting portion in Examples, etc., wherein (a) is Example 1, Comparative Examples 1 to 4, and (b) is Example. 2 and (c) are diagrams showing grooves formed in Example 3, respectively. FIG. 10 is a front view conceptually showing the shape of various concave grooves formed in the cover fitting portion in Examples etc., wherein (a) is Example 4, (b) is Example 5, and (c) is It is the figure which showed the concave groove formed in Example 6, respectively.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the container for food packaging which concerns on this invention is described in detail based on drawing.

The food packaging container 1 according to the present invention comprises, as shown in FIG. Prepare.

The container body 10 includes a bottom portion 11, a side wall portion 12 rising from the bottom portion 11, a body fitting portion 13 formed at an inner opening end of the side wall portion 12, and an outer and a body flange portion 14 formed toward. In the illustrated embodiment, the bottom portion 11 is formed with an annular convex portion 15 that functions as a pedestal, and the vicinity of the center is curved inwardly (upwardly). The side wall portion 12 is formed as an inclined surface expanding upward from the bottom portion 11 (see FIGS. 1 and 3).

In the illustrated embodiment, the main body fitting portion 13 has a main body abutment surface 13a formed to protrude outward from the upper end of the side wall portion 12, and a vertical or inward inclination from the outer end of the main body abutment surface 13a. and a main body fitting surface 13b (see FIG. 3). The vertical length of the body fitting portion 13 is preferably 0.5 to 2 cm, more preferably 0.8 to 1.5 cm.

The container body 10 has, for example, a circular shape with a diameter (L) of 10-25 cm and a depth (H) of 2-10 cm, preferably a circular shape with a diameter of 15-23 cm and a depth of 2.5 cm. 5 to 8 cm. Also, the ratio of diameter to depth (L/H) is preferably 2-7. In particular, the food packaging container 1 according to the present invention is effective when the depth of the container body 10 is relatively shallow and liquid leakage is likely to occur during transportation, such as when the ratio is 4-6.

The material of the container body 10 is not particularly limited and may be paper, synthetic resin, metal, glass, or the like, but synthetic resin sheets, particularly thermoplastic resin foam sheets, for example, polyethylene resin foam sheets formed by extrusion foaming, polypropylene resin, etc. Thermoformed products such as foamed sheets, polystyrene-based resin foamed sheets, polyester-based resin foamed sheets, and polylactic acid-based resin foamed sheets are preferably used. Considering the use of microwave oven heating, the material for the container body 10 is particularly preferably a thermoformed polypropylene resin foam sheet or a polystyrene resin foam sheet having a Vicat softening point of 110° C. or higher.

When a thermoplastic resin foam sheet is used as the material for the container body 10, the thickness of the foam sheet is generally 0.05 to 10 mm, preferably 1 to 5 mm, and more preferably 1.5 to 8 mm. is. Within the above range, the foamed sheet does not have insufficient rigidity and strength, and is excellent in terms of light weight and cost. The density of the foamed sheet is generally 5-500 kg/m ³ , preferably 50-150 kg/m ³ , more preferably 60-130 kg/m ³ . Within the above range, the strength of the container after secondary molding does not decrease, and it is desirable from the viewpoint of weight reduction and heat insulation.

Thermoforming methods for the container body 10 using the thermoplastic resin foam sheet include vacuum forming, pressure forming, and applications thereof such as free drawing forming, plug and ridge forming, ridge forming, matched mold forming, and the like. Straight molding, drape molding, reverse draw molding, air slip molding, plug-assisted molding, plug-assisted reverse load molding, etc., or a combination thereof can be employed.

The lid body 30 includes a top plate portion 31, a lid body fitting portion 32 that hangs down from the periphery of the top plate portion 31 and fits inside the main body fitting portion 13 of the container body 10, and the lid body fitting portion. A lid body flange portion 33 which overlaps with the flange portion 14 of the container body 10 formed on the upper edge of the container body 10 when the lid is closed is provided. In the illustrated embodiment, the lid 30 has a peripheral wall portion 34 that hangs down from the peripheral edge of the top plate portion 31 , and the above-described lid fitting portion 32 is formed outside the lower edge of the peripheral wall portion 34 . . An annular convex portion 35 is formed on the top plate portion 31 to reinforce the top plate portion (see FIGS. 1, 2 and 3).

In the illustrated embodiment, the lid fitting portion 32 includes a lid abutment surface 32a formed so as to protrude outward in the horizontal direction from the lower edge of the peripheral wall portion 34, and an outer surface of the lid abutment surface 32a. A lid body fitting surface 32b is formed from the end so as to follow the body fitting surface 13b of the container body so as to be vertically or inwardly inclined upward (see FIG. 3). The vertical length of the lid fitting portion 32 (in the illustrated embodiment, the length from the lower end of the peripheral wall portion 34 to the lower end of the lid flange portion 33) is 0.5 to 2 cm. It is preferably 0.8 to 1.5 cm, more preferably 0.8 to 1.5 cm.
Here, "fitting" refers to a fitting method in which the lid body fitting portion 32 is fitted into the main body fitting portion 13b when the lid is closed. Further, the fitting surface refers to a region from the uppermost end to the lowermost end of the portion where the lid body fitting portion 32 and the main body fitting portion 13b are in contact when the lid is closed. A portion where the portion 13b and the lid fitting portion 32 are not in contact with each other may be included. Inner fitting refers to a fitting method in which the peripheral edge of the lid is fitted inside the opening edge of the container body when the lid is closed.

The lid flange portion 33 formed at the upper end of the lid fitting portion 32 effectively prevents liquid from leaking from the contents and effectively prevents foreign matter from entering the container body when the lid is closed. It is preferable to cover 70% or more, more preferably 90% or more, of the width of the main body flange portion 14 formed in the center. Further, it is preferable that the cover body flange portion 33 is knurled 36 as shown in FIG. When the liquid from the contents passes through the flange portion from the inside to the outside of the container, it does not go straight due to the grooves formed by the knurling 36 but spreads in the lateral direction. can be effectively suppressed. In knurling, the twill module m is preferably 0.2, 0.3, or 0.5. Further, it is preferable that the cover body flange portion 33 is further formed with a knob portion 37 which protrudes a part thereof outward.

The lid body 30 is formed of a synthetic resin sheet, specifically a thermoplastic resin sheet such as polyethylene, polypropylene, polystyrene, or polyethylene terephthalate, or a biodegradable thermoplastic resin sheet such as polylactic acid. is preferred. Although the thickness of the synthetic resin sheet to be used is appropriate, it is generally 1 mm or less, and usually 0.2 to 0.7 mm. The synthetic resin sheet is preferably formed by vacuum forming. Considering the mass productivity, processing accuracy, etc., when using a synthetic resin sheet as a raw material, vacuum forming is simple and optimal.

In the present invention, the lid body fitting portion 32 of the lid body 30 and/or the body fitting portion 13 of the container body 10 described above discharges water vapor generated in the container during heating of the contents to the outside of the container. A recessed groove is formed to construct a passageway through which the
A mode in which the groove 40 is formed in the lid fitting portion 32 of the lid will be described in detail below with reference to the drawings. can be From the viewpoint of ease of handling, it is preferable that the groove 40 is formed at least in either the lid fitting portion 32 or the body fitting portion 13 . Moreover, from the viewpoint of easily forming the food packaging container according to the present invention, it is preferable that the concave groove is formed in the lid fitting portion 32 of the lid. In addition, the concave groove is not limited to a concave shape, and includes a V-shape, a U-shape, and the like, as long as the shape has an open upper surface.

For example, in FIG. 1, a groove 40 is formed in the lid fitting portion 32 of the lid. The recessed groove 40 communicates from the lower end to the upper end of the lid body fitting portion 32 so that a passage for discharging gas such as water vapor to the outside of the container is formed between the body fitting portion 13 and the body fitting portion 13 . and an angle (∠AZB ) is formed to be 50 degrees or more. (See Figures 1, 4 and 5). In this way, the lid body fitting portion 32 is formed with the recessed groove 40 in which the water vapor inlet (A) and the water vapor outlet (B) are separated from each other in the circumferential direction of the fitting portion. As a result, even when the container is tilted, it is possible to effectively prevent the contents from leaking out of the container through the concave groove 40 (see FIGS. 6 and 7). From this point of view, the plane view angle (∠AZB) is preferably 60 degrees or more, more preferably 80 degrees or more. The upper limit of the plan view angle (∠AZB) is not particularly limited, but it should be 180 degrees or less from the viewpoint of the ease of designing the path in the concave groove and the ease of molding the lid. is preferred.

In addition, the plane view angle (∠AZB) in the present invention is an angle measured at the position where the formed concave groove 40 has the minimum separation angle.
That is, as shown in FIG. 4, when the groove 40 is formed in the cover fitting portion 32, the inlet of the groove for water vapor or the like becomes an open end 40a with a width at the lower end. The outlet such as the outlet has a wide open end 40b at the upper end. The internal angle of the plane view angle (∠AZB) is measured from (A) and the point (B) at the outlet.
Also, as shown in FIG. 5, when the lid body fitting portion 32 is formed with two open ends 40a1, 40a2 and 40b1, 40b2 as inlets and outlets for water vapor and the like, respectively, the concave grooves 40 shown in FIG. As described above, the point (A) of the open end 40a1 at the lower end and the point (B) of the open end 40b1 at the upper end are the opening ends where the distance between the inlet and the outlet in the circumferential direction is the shortest, and the above plane view angle ( ∠AZB).
Also, even if the planar shape of the cover is circular, elliptical, square, etc., the planar view angle (∠AZB) is measured with the central point of the figure as the center (Z) of the cover. In the case where a groove is formed in the body fitting portion 13 of the container body, in a state where the lid is attached to the container body, the inlet (A) for water vapor or the like in the groove formed in the body fitting portion, The internal angle of the plan view angle (∠AZB) formed by the center (Z) of the lid and the outlet (B) for water vapor or the like is measured as described above.

It is preferable that 3 to 10, more preferably 4 to 8, discharge passages for water vapor or the like are formed at different positions in the circumferential direction of the container. If it is within the above range, when the lid is attached to the container body, the gas in the container will not easily escape, making it difficult for the lid to fit. The lid does not come off from the container body without being efficiently discharged into the container, and the container itself and the lid do not deform, and the balance between the sealability of the contents and the handleability when the lid is opened is excellent. become a thing. In addition, in the plurality of passages, the inlet (A) or the outlet (B) may be displaced from the inlet (A) or the outlet (B) of another adjacent passage. For example, as shown in FIG. 2, it is preferable that the passages are constructed so as to overlap each other so that the passages do not cross each other. Moreover, the passage is preferably formed in the lid fitting portion 32 from the viewpoint of formability.

Further, the ratio (s/S) of the total opening area (s) of the groove 40 to the area (S) of the fitting surface between the lid body fitting part and the main body fitting part is 0.2 to 0. .6 is preferred. Within the above range, when the lid is attached to the container body, it is difficult to fit the lid, and when the contents are heated in the microwave oven, the steam generated from the contents is not efficiently discharged to the outside of the container. will not come off from the container body, and the container itself will not be expanded and deformed. In addition, it is possible to prevent foreign matter from entering the container and leakage of the contents to the outside of the container due to deterioration of the sealing performance of the container. From this point of view, the ratio (s/S) is more preferably 0.25 to 0.5.
The area (S) of the fitting surfaces of the lid body fitting portion 32 and the body fitting portion 13 and the total opening area (s) of the groove 40 were obtained from the outer dimensions of the lid body or the container body. It is a thing. More specifically, the area (S) of the fitting surface is defined by the length of the fitting surface between the lid body fitting portion 32 and the body fitting portion 13 in the circumferential direction at the middle portion in the vertical direction and the vertical length of the fitting surface. It can be obtained from the direction length. The total opening area (s) of the grooves 40 can be obtained from the outer dimensions of the opening area of the grooves 40 on the fitting surface side. It should be noted that the fitting surfaces of the lid body fitting portion 32 and the body fitting portion 13 do not necessarily have to fit the entire surfaces of the lid body fitting portion 32 and the body fitting portion 13, but are preferably , the fitting portions are preferably in contact with each other except for the groove 40 .

Also, the total passage volume (v) of the passages is preferably 1 to 5 cm ³ , more preferably 1.5 to 4.5 cm ³ . Within the above range, when the lid is attached to the container body, it is difficult to fit the lid, and when the contents are heated in the microwave oven, the water vapor generated from the contents is not efficiently discharged to the outside of the container, and the lid is stuck. There is no fear that the container will come off from the container body or the container itself or the lid will be deformed. In addition, it is possible to prevent foreign matter from entering the container and leakage of the contents to the outside of the container due to deterioration of the sealing performance of the container.
From the same viewpoint as above, the ratio (v/V) of the total passage volume (v) of the passage to the volume (V) of the container is preferably 0.0025 to 0.0075, and 0.003 to 0. 0.007 is more preferred.
The total passage volume (v) and the volume (V) of the container are obtained from the outer dimensions of the container when the lid is attached to the container body.

The width and depth of the recessed groove 40 formed in the lid body fitting portion 32 are particularly limited as long as the total passage volume (v), area ratio (s/S), and volume ratio (v/V) of the passages described above are satisfied. Although not required, the depth is preferably 0.5 mm or more and 2 mm or less from the viewpoint of making it easier to release the lid from the mold when it is thermoformed and preventing foreign matter from entering. Further, the width of the concave groove is preferably 2 to 5 mm, more preferably 2.5 to 4 mm.

Foods such as rice and side dishes are housed in the container body 10 described above, and after fitting the lid body 30 described above, a shrink film (not shown) can be covered as necessary to form a packaging body. . The shrink film can prevent the cover body 30 from being accidentally detached from the container body 10 and the container body 10 from being illegally opened.

As the shrink film, known heat-shrinkable materials are widely used, for example, polyolefins such as polypropylene and polyethylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, ethylene-propylene copolymer and ethylene-vinyl acetate copolymer. , ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, vinyl chloride-vinyl acetate copolymer, etc. A coalescence etc. can be mentioned. Films using these resins can be used as uniaxially stretched or biaxially stretched films. Laminated films obtained by laminating these resins can also be used. In particular, when printing is applied to a shrink film, a film such as polypropylene or polyethylene terephthalate, which is easy to print, or a laminate film using these on the printing surface side is preferably used.

According to the food packaging container 1 according to the present invention described above, when the lid 30 is normally attached to the container body 10 (when the lid is closed), the lid body fitting portion 32 of the lid body 30 is positioned at the container body 10 . In addition, since the main body flange portion 14 of the container body 10 and the lid body flange portion 33 of the lid body 30 are in contact with each other, foreign matter does not enter the container. can be effectively suppressed. In particular, the body fitting portion 13 is composed of a body abutment surface 13a and a body fitting surface 13b, and the lid body fitting portion 32 is composed of a lid body butting surface 32a and a lid body fitting surface 32b. When the lid abutment surface 31a abuts against the main body abutment surface 13a when the lid is closed, the fitting operation of the lid 30 to the container body 10 is facilitated, and the airtightness is further improved. be able to.

Further, according to the food packaging container 1 according to the present invention described above, when the stored contents are heated, the contents are heated through the grooves 40 formed in the lid fitting portion 32 and/or the body fitting portion 13 . Internal pressure is applied to the cover flange portion 33, creating a gap between it and the main body flange portion 14, and water vapor generated by heating the contents is easily discharged to the outside through the concave groove 40. . In addition, since the recessed groove 40 that achieves the functions and effects described above can be formed during molding of the lid body or the container body, the productivity is also excellent.

In addition, the concave groove 40 formed in the lid body fitting portion 32 and/or the main body fitting portion 13 in order to build a passage for discharging water vapor or the like generated in the container to the outside of the container, which will be described later, is used for the water vapor or the like. The plane view angle (∠AZB) formed by the inlet (A) of the lid, the center (Z) of the lid, and the outlet (B) for steam etc. was 50 degrees or more, so the container was tilted Even in the case where the container is closed, it is possible to effectively prevent the contents from leaking out of the container through the concave groove 40 .
For example, when the container 1 is tilted as shown in FIG. Since the possibility that the liquid is immersed in the inlet (A) and the outlet (B) at the same time is reduced, leakage of the contents can be effectively prevented.
In addition, when the container 1 is tilted as shown in FIG. 7, even if the liquid of the contents is immersed in the inlet (A), there is no risk of the liquid being immersed in the outlet (B) side. can effectively prevent liquid leakage.

As described above, according to the food packaging container 1 of the present invention, it is possible to effectively suppress the intrusion of foreign substances into the container and the leakage of liquid from the contents. It is possible to effectively dissipate the water vapor generated in the container to the outside of the container and suppress the increase in the internal pressure of the container.

Examples of the food packaging container according to the present invention are described below together with comparative examples, but the present invention is not limited to these examples.

A container body 10 having the shape illustrated in FIGS. 1 and 3 was formed by vacuum forming a polystyrene resin foam sheet (Vicat softening point: 118° C., thickness: 1.7 mm, density: 100 kg/m ³ ). 1 to 3, and the recessed grooves of various shapes and sizes shown in Examples 1 to 6 and Comparative Examples 1 to 4 described below in the lid body fitting portion 32. A container for pasta was formed by hot-plate heating and vacuum molding a sheet material of heat-resistant biaxially oriented polystyrene (heat-resistant OPS) resin having a thickness of 0.3 mm.
The resulting container (container main body 10 with lid 30 attached) was circular in plan view (diameter about 20 cm) and had a volume (V) of 500 cm ³ . The lid fitting portion 32 of the lid 30 had a height of 11.3 mm and a total area (S) of 64.6 cm ² .

-Example 1-
Three recessed grooves 40, which are passages having the shape shown in FIG. The planar view angle (∠AZB), the total opening area (s), the area ratio (s/S), the total passage volume (v), and the volume ratio (v1/V) of the formed concave groove 40 are shown in Table 1. shown as 1.
Further, the cover flange portion 33 is knurled with a twill module m=0.5.

- Examples 2 to 6, Comparative Examples 1 to 4 -
Food packaging containers of Examples 2 to 6 and Comparative Examples 1 to 4 were produced in the same manner as in Example 1, except that the following items were changed.
Example 2: The concave grooves 40 having two inlets and two outlets for water vapor or the like shown in FIG. Formed the book. The plane view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Example 2, respectively. The number of discharge passages (the number of recessed grooves) was counted as one passage even when a plurality of inlets and outlets were formed, when they joined at a passage portion.
Example 3: Eight recessed grooves 40 having the shape shown in FIG. The planar view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Example 3, respectively.
Example 4 Four concave grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed groove 40 and the like are shown in Table 1 as Example 4, respectively.
Example 5 Five concave grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed groove 40 is shown in Table 1 as Example 5, respectively.
Example 6 Three concave grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed groove 40 and the like are shown in Table 1 as Example 6, respectively.
Comparative Example 1: Eight concave grooves 40 having the shape shown in FIG. The plan view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Comparative Example 1, respectively.
Comparative Example 2 Fifteen concave grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Comparative Example 2, respectively.
Comparative Example 3: Thirty-six concave grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Comparative Example 3, respectively.
Comparative Example 4 Sixteen recessed grooves 40 having the shape shown in FIG. The plane view angle (∠AZB) of the formed concave groove 40 is shown in Table 1 as Comparative Example 4, respectively.

The lids 30 of Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to the following leak test and microwave oven heating test to evaluate their performance.
Leakage test was performed by placing 40 ml of extra virgin olive oil in the container body 10, attaching the lids 30 of Examples 1 to 6 and Comparative Examples 1 to 4, and standing the container upright, and checking that no leakage occurred for 60 seconds or longer. ◯ (accepted), and x (failed) for leakage.
In the microwave heating test, 240 g of boiled spaghetti noodles were placed in the container body 10, and 130 g of commercially available meat sauce with plenty of Ma-Ma tomato pulp was applied on top of it. Each lid 30 is attached and heated in a microwave oven (1800 W for 60 seconds), and the lid does not come off for 60 seconds or more ◎ (accepted). Those that came off in less than 50 seconds were evaluated as x (failed).
The above performance evaluation results are also shown in Table 1.

The food packaging container according to the present invention can effectively suppress the intrusion of foreign substances into the container, and can effectively dissipate the water vapor generated when the contents are heated to the outside of the container, Since an increase in the internal pressure of the container can be suppressed, it can be suitably used as a food packaging container for storing and selling foods such as boxed lunches, particularly at convenience stores and the like.

Reference Signs List 1 food packaging container 10 container main body 11 bottom 12 side wall 13 main body fitting portion 13a main body butting surface 13b main body fitting surface 14 main body flange portion 15 annular protrusion 30 lid 31 top plate portion 32 lid fitting portion 32a Lid abutment surface 32b Lid fitting surface 33 Lid flange 34 Peripheral wall 35 Annular projection 36 Knurling 37 Knob 40 Groove

Claims (8)

A food packaging container comprising a container body and a lid that fits inside the container body,
The container body includes a bottom portion, a side wall portion rising from the bottom portion, a body fitting portion formed at an inner opening end of the side wall portion, and an upper edge of the body fitting portion formed outwardly. and a main body flange,
The lid includes a top plate portion, a lid fitting portion that hangs down from the peripheral edge of the top plate portion and fits inside the body fitting portion of the container body, and overlaps the body flange portion when the lid is closed. a lid flange portion formed on the upper edge of the lid fitting portion;
A concave groove for constructing a passage for discharging water vapor or the like generated in the container to the outside of the container is formed in the lid body fitting portion and/or the main body fitting portion,
The plane view angle (∠AZB) formed by the inlet (A) for water vapor, etc., the outlet (B) for water vapor, etc. in the concave groove, and the center (Z) of the lid is 50 degrees or more. A food packaging container, characterized by: 2. The food packaging container according to claim 1, wherein 3 to 10 passages are formed at different positions in the circumferential direction of the container. The ratio (s/S) of the total opening area (s) of the grooves to the area (S) of the fitting surfaces of the lid body fitting part and the body fitting part is 0.2 to 0.6. The food packaging container according to claim 1 or 2, characterized by: The food packaging container according to any one of claims 1 to 3, wherein the width of the opening of the concave groove is 2 to 5 mm. Food packaging container according to any one of claims 1 to 4, characterized in that the total passage volume (v) of said passages is between 1 and 5 cm ³ . Claims 1 to 5, characterized in that the ratio (v/V) of the total passage volume (v) of the passage to the volume (V) of the food packaging container is 0.0025 to 0.0075. Food packaging container according to any one of. 7. The food packaging container according to any one of claims 1 to 6, wherein the flange portion of the lid body is knurled. The food packaging container according to any one of claims 1 to 7, wherein the food packaging container is substantially circular in plan view.

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