Lid for a container for cooking using a microwave oven

Abstract

To provide a lid of a container for microwave oven cooking capable of reducing a formation area of a vapor discharge part to be formed, operating even under a relatively low internal pressure of a container, and surely maintaining a closed state under an atmospheric pressure.SOLUTION: A lid has a vapor discharge part formed so that two or more linear slits form one annular shape. Both ends in the extending direction of each of the two or more linear slits face each other at a predetermined distance from the end in the extending direction of the adjacent linear slits. Preferably, the length of each of the opposed portions of the linear slit is in the range of 10% or more to 50% or less of the length of the linear slit located outside the annular shape in the opposed portion of the linear slit. Preferably, each distance between the linear slits facing each other is 25% or less of the length of the linear slit located outside the annular shape in the opposed portion of the linear slit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lid for a container for cooking with a microwave oven.

Background Art

[0002] In convenience stores, supermarkets, etc., various bento boxes and cooked foods containing food in plastic containers are sold in large numbers. The containers used here are composed of a container body with an upper opening capable of accommodating food, etc., and a lid detachably attached to the upper opening of this container body. After the food is accommodated in the container body, the lid is attached to the opening of the container body, and the container body and the lid are fixed with a film packaging material. Then, it is heated in a microwave oven with the container body and the lid fixed with a film packaging material.

[0003] In a container for cooking with a microwave oven used for such applications, it is necessary to ensure airtightness so that the juice, etc. of the food accommodated in the container body does not leak to the outside. Also, it is necessary to release the generated steam outside the container so that the container body and the lid do not expand excessively or rupture due to the steam generated when heated in a microwave oven. Therefore, a steam release part composed of a valve or a hole is provided in the lid to release the generated steam outside the container.

[0004] On the other hand, when a steam release part composed of a valve or a hole is provided in the lid, it is necessary to prevent dust, insects, foreign substances, etc. from entering the container from the valve or the hole.

[0005] Therefore, the applicant of the present application proposed a lid in which a recess recessed toward the container body side is provided in the top plate part of the lid, a plurality of cuts are provided on the bottom surface of the recess, and the bridge-shaped part between the cuts is lifted upward by the pressure inside the container, and the steam inside the container is released to the outside through the gap formed thereby (Patent Document 1).

[0006] In Patent Document 2 as well, a recess having a bottom surface curved downward is recessed downward on the top surface of the lid body, a raised portion that protrudes upward and is formed high is formed on the bottom surface of the recess, and a plurality of linear slits are formed at intervals on the raised portion, and a lid body is proposed in which deformation suppressing ribs are formed between adjacent slits and near both ends of the slit.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] In recent years, from the viewpoint of improving the designability of the lid body, etc., it has been required to make the area of the steam release portion formed on the lid body as small as possible. Also, while the steam release portion of the lid body operates even at a relatively low container internal pressure, it is also required to be in a completely closed state under non-heated conditions (under atmospheric pressure).

[0009] The present invention has been made in view of such demands, and its object is to make the steam release portion formed on the lid body of a container that is heat-cooked by a microwave oven have a small formation area, be operable even at a relatively low container internal pressure, and be able to surely maintain a closed state under atmospheric pressure.

Means for Solving the Problems

[0010] The lid of the container for heating and cooking in a microwave oven according to an embodiment of the present invention for achieving the above object (hereinafter, may be simply referred to as "lid") is a lid of a container that is heated and cooked by a microwave oven, and has a steam release portion formed such that two or more linear slits form one annular shape, and both ends in the extending direction of each of the two or more linear slits face each other with a predetermined distance from the extending direction ends of adjacent linear slits.

[0011] In the lid having the above configuration, it is preferable that the length of each of the opposing portions of the linear slit is 10% or more and 50% or less of the length of the linear slit located outside the annular shape in the opposing portion.

[0012] Also, in the lid having the above configuration, it is preferable that the distance between each of the opposing linear slits is 25% or less of the length of the linear slit located outside the annular shape in the opposing portion.

[0013] Also, in the lid having the above configuration, one end in the extending direction of each of the two or more linear slits may be located inside the annular shape rather than the extending direction end of the adjacent linear slit, and the other end in the extending direction may be located outside the annular shape rather than the extending direction end of the adjacent linear slit. Here, it is preferable that the steam release portion is formed such that three or more of the linear slits form one annular shape.

[0014] Also, in the lid having the above configuration, both ends in the extending direction of each of the two or more linear slits may be located either inside or outside the annular shape rather than the extending direction ends of the adjacent linear slits. Here, it is preferable that the steam release portion is formed such that six or more of the linear slits form one annular shape.

[0015] Also, in the lid having the above configuration, it is preferable that the length of one linear slit is 5 mm or more and 40 mm or less.

[0016] In the lid of the above-described configuration, it is preferable that the annular shape formed by the two or more linear slits is a square shape or a circular shape.

[0017] In the lid of the above-described configuration, it is preferable that the two or more linear slits have the same shape and are in a shape where the middle part of the straight line is bent.

[0018] In the lid of the above-described configuration, it is preferable that the two or more linear slits have the same arc shape.

Advantages of the Invention

[0019] In the lid according to the present invention, since the amount of steam released per formation area of the steam release part is larger than before, the formation area of the steam release part can be made smaller than before. Also, the steam discharge part can operate even at a stage where the internal pressure of the container is relatively small. And further, the steam discharge part can surely maintain a closed state in a non-heated state (under atmospheric pressure).

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0021] Hereinafter, the lid according to the present invention will be further described with reference to the drawings, but the present invention is not limited to these embodiments at all. Also, the X direction, Y direction, and vertical direction in this specification shall respectively mean the X direction, Y direction, and vertical direction shown in these drawings.

[0022] (First Embodiment) FIG. 1 shows an example of a container V for cooking using a microwave oven. The container V for cooking using a microwave oven shown in this figure includes a container body 1 having an inverted frustum shape with an upper surface opening, and a lid 2 that seals the upper surface opening of the container body 1. The container body 1 has a disk-shaped bottom wall 11 and a peripheral wall 12 that slopes upward from the periphery of the bottom wall 11 toward the outside in the radial direction. And a first engaging portion 13 for removably mounting the lid 2 is provided at the upper part of the peripheral wall 12 of the container body 1. The bottom wall 11, the peripheral wall 12, and the first engaging portion 13 are integrally formed, for example, by thermoforming a heat-resistant resin having foaming properties using a mold.

[0023] On the other hand, the lid 2 includes a circular top wall 21, an outer peripheral wall 22 that slopes downward from the periphery of the top wall 21 toward the outside in the radial direction, a flange portion 23 that extends substantially horizontally outward in the radial direction from the lower peripheral end of the outer peripheral wall 22, and a second engaging portion 24 formed on the outer peripheral portion of the flange portion 23 that engages airtightly with the first engaging portion 13 of the container body. A square recess 25 is formed in a substantially central portion of the top wall 21 in plan view. And a steam release portion 4a in which four bent linear slits are arranged in a square ring shape is provided at a substantially central portion of the bottom surface 25a of the recess 25. The top wall 21, the outer peripheral wall 22, the flange portion 23, the second engaging portion 24, and the recess 25 are integrally formed, like the container body 1, for example, by thermoforming a heat-resistant resin using a mold.

[0024] As the material of the lid body 2, for example, resins such as polyethylene terephthalate, polystyrene, polypropylene, and polyethylene can be used. Further, those obtained by adding a foaming agent to these resins or those obtained by stretching the resins can also be used. From the viewpoint of making it possible to visually recognize the state of the contents from the outside of the container, those having transparency are preferable.

[0025] After noodles, rice, food ingredients, etc. that can be eaten as they are by being cooked by heating in a microwave oven are accommodated as contents in the container body 1, the upper surface opening of the container body 1 is hermetically sealed by the lid body 2, and further, if necessary, the outer periphery of the container V is packaged with a resin film or the like.

[0026] Fig. 2 shows a plan view of the steam release portion 4a formed on the bottom surface 25a of the recess 25 of the lid body 2. The steam release portion 4a is arranged such that four slits 41a to 41d having the same shape with the center of the straight line bent at a right angle form a square ring shape. Specifically, both ends in the extending direction of each of the four linear slits 41a to 41d face each other across a predetermined distance D and over a length N from the end in the extending direction of the adjacent linear slit, and one end in the extending direction of each of the linear slits 41a to 41d is located inward of the annular shape from the end in the extending direction of the adjacent linear slit, and the other end in the extending direction is located outward of the annular shape from the end in the extending direction of the adjacent linear slit.

[0027] The steam release part 4a with such a configuration can also be regarded as having a substantially rectangular elevating part 5a surrounded by the inner part of the four linear slits 41a to 41d in a square ring shape, and linear bridge parts 61a to 61d that are opposite parts of adjacent linear slits, that is, linear bridge parts sandwiched by adjacent linear slits. As will be described later, when the internal pressure of the container V increases, the elevating part 5c moves upward. One end of each of the four bridge parts 61a to 61d is connected to the four corner parts of the substantially rectangular elevating part 5a, and the other end is connected to the bottom surface 25a of the concave part 25. The four bridge parts 61a to 61d function such that the elevating part 5a moves upward in a state substantially parallel to the bottom surface 25a of the concave part 25 in response to the internal pressure of the container. The elevating part 5a moves upward when the internal pressure of the container V increases and moves downward when the internal pressure decreases. When the internal pressure of the container becomes atmospheric pressure, the elevating part 5a and the bridge parts 61a to 61d are positioned in the same plane as the bottom surface 25a of the concave part 25.

[0028] Note that when heat cooking is performed using a microwave oven, it is acceptable that the elevating part 5a remains in the upwardly moved state for a predetermined time, and the bridge parts 61a to 61d are plastically deformed so that the elevating part 5a does not return to its original state (flush with the bottom surface 25a of the concave part 25) after heat cooking. Generally, after heat cooking, the container contents are served for eating, so the lid 2 is removed from the container body 1.

[0029] Here, in the lid 2 of the present invention, it is preferable that the length N of each of the opposing portions of the linear slits 41a to 41d is 10% or more and 50% or less of the length L of the linear slits located outward in an annular shape in the opposing portions. If the length N of each of the opposing portions of the linear slits is less than 10% of the length L of the linear slits, the movable distance upward of the elevating portion 5a may be short and an opening for discharging the vapor in the container to the outside may not be sufficiently formed. Also, there is a risk that the internal pressure of the container when the elevating portion 5a moves upward may become too high. On the other hand, if the length N of each of the opposing portions of the linear slits exceeds 50% of the length L of the linear slits, there is a risk that the elevating portion 5a may drop downward due to its own weight and an opening may occur in the lid portion 2 during non-heating such as transportation and storage. The preferable range of the length N of each of the opposing portions of the linear slits is 15% or more and 50% or less of the length L of the linear slits. The length N of the opposing portions of the linear slits may be different for each of the opposing portions of the linear slits, but from the viewpoint of the elevating portion 5a moving smoothly upward corresponding to the internal pressure of the container in a state substantially parallel to the bottom surface 25a of the concave portion 25, it is preferable that the length N of each of the opposing portions of the linear slits is the same.

[0030] Also, it is preferable that the distance D between the opposing linear slits is 25% or less of the length L of the linear slits located outward in an annular shape in the opposing portions. If the distance D between the opposing linear slits exceeds 25% of the length L of the linear slits, there is a risk that even when the internal pressure of the container increases, the elevating portion 5a may not move sufficiently outward and the vapor in the container V cannot be smoothly discharged to the outside. A more preferable upper limit value of the distance D between the opposing linear slits is 40% of the length L of the linear slits. Also, a preferable lower limit value of the distance D between the opposing linear slits is 5% of the length L of the linear slits. The distance D between the opposing linear slits may be different for each of the opposing portions of the linear slits, but from the viewpoint of the elevating portion 5a moving smoothly upward corresponding to the internal pressure of the container in a state substantially parallel to the bottom surface 25a of the concave portion 25, it is preferable that the distance D between the opposing linear slits is the same.

[0031] Fig. 3 shows a perspective view showing a state in which steam is ejected from the steam ejection part 4a. When the internal pressure of the container V increases, the elevating part 5a moves upward while maintaining a substantially parallel state with respect to the bottom surface 25a of the concave part 25 by the bridge-like parts 61a to 61d. Thereby, an opening 80 is formed between the bottom surface 25a of the concave part 25 and the elevating part 5a. Ignoring the thickness of the bridge-like parts 61a to 61d, the opening 80 opens over the entire circumference between the bottom surface 25a of the concave part 25 and the elevating part 5a, and it is possible to efficiently release the steam inside the container to the outside with a smaller formation area compared to the conventional linear opening. Further, when the internal pressure of the container becomes high, the elevating part 5a moves further upward, the opening area between the elevating part 5a and the bottom surface 25a of the concave part 25 becomes larger, and the release of the steam inside the container is further promoted.

[0032] The number of formed linear slits is not limited to four and may be two or more. However, in the case of this embodiment, it is preferably three or more. As described above, it is preferable from the viewpoint of efficient steam release that the elevating part 5a moves upward and is held in a substantially parallel state with respect to the bottom surface 25a of the concave part 25. When there are two linear slits, the bridge-like parts supporting the elevating part 5a are formed only at two opposite positions of the elevating part 5a, and it is difficult to maintain the parallel state of the elevating part 5a. If there are three or more linear slits, since three or more bridge-like parts supporting the elevating part 5a are formed, the parallel state of the elevating part 5a is stably maintained.

[0033] There is no particular limitation on the length L of one linear slit, but considering the size of the lid 2 of the container heated by a microwave oven, it is preferably 5 mm or more and 40 mm or less. If the length L of the linear slit is less than 5 mm, there is a possibility that the steam inside the container cannot be smoothly released by the steam ejection part 4a. On the other hand, if the length L of the linear slit exceeds 40 mm, there is a possibility that the design property of the container deteriorates. A more preferable range of the length L of the linear slit is 12 mm or more and 30 mm or less.

[0034] The linear slits 41a to 41d are preferably formed by cutting with a blade having a predetermined shape, for example. A large gap is not formed between the opposing cut surfaces of the linear slit after cutting, preventing the intrusion of dust, dirt, larvae, etc. into the container. Also, since leakage of internal vapor from the linear slit is suppressed when the pressure inside the container has not yet risen sufficiently. Of course, the linear slit may be formed by laser processing as long as the intrusion of dust, dirt, small insects, etc. into the container is suppressed and the leakage of internal vapor is suppressed.

[0035] (Modification 1) FIG. 4 shows a plan view of a modification of the steam release part, and FIG. 5 shows a perspective view of a state where steam is ejected from the steam release part. The steam release part 4b shown in these figures is the same as the steam release part 4a of the first embodiment in that four linear slits 42a to 42d having a shape in which the center of a straight line is bent at a right angle form a square ring shape. However, in this modification, both ends in the extending direction of the linear slits 42b and 42d are located outside the square ring compared to the ends in the extending direction of the adjacent linear slits 42a and 42c. In other words, both ends in the extending direction of the linear slits 42a and 42c are different in that they are located inside the square ring compared to the ends in the extending direction of the adjacent linear slits 42b and 42d.

[0036] Even with the steam release part 4b having such a configuration, when the internal pressure of the container V increases, the elevating part 5b moves upward. One end of each of the four bridge-like parts 62a to 62d is connected to the bottom surface 25a of the concave part 25, and the other ends of the bridge-like parts 62a and 62d and the other ends of the bridge-like parts 62b and 62c are connected to the diagonal parts of the elevating part 5b, functioning such that the elevating part 5b moves upward in a state substantially parallel to the bottom surface 25a of the concave part 25 in response to the internal pressure of the container. Similar to the first embodiment, the elevating part 5b moves upward when the internal pressure of the container V increases and moves downward when the internal pressure decreases. When the internal pressure of the container becomes atmospheric pressure, the elevating part 5b and the bridge-like parts 62a to 62d come to be located in the same plane as the bottom surface 25a of the concave part 25.

[0037] However, in the steam release part 4b composed of four linear slits 42a to 42d as in this modification example, since the elevating part 5b is supported by the bridge-like parts 62a, 62d and the bridge-like parts 62b, 62c at two diagonal positions, it may be difficult to be stably supported in a state substantially parallel to the bottom surface 25a of the concave part 25. In order for the elevating part 5b to be stably supported in a substantially parallel state, it is preferable that the elevating part 5b is supported by bridge-like parts at at least three positions. In this case, the number of linear slits required is six or more.

[0038] In addition, the preferred ranges of the length L of the linear slit, the length N of each opposing part of adjacent linear slits, and the distance D between opposing linear slits are also applicable here as exemplified in the first embodiment.

[0039] (Second Embodiment) FIG. 6 shows a plan view showing a second embodiment of the steam release part. In the steam release part 4c shown in this figure, four semi-circular arc-shaped linear slits 43a to 43d are arranged so as to form an annular shape. Specifically, one end of each of the four semi-circular arc-shaped linear slits 43a to 43d in the extending direction is located inside the annular shape from the end in the extending direction of the adjacent linear slit, and the other end in the extending direction is arranged so as to be located outside the annular shape from the end in the extending direction of the adjacent linear slit.

[0040] The steam release part 4c can also be regarded as having a substantially circular elevating part 5c surrounded by the parts of the four linear slits 43a to 43d located inside the annular shape, and four arc-shaped bridge-like parts 63a to 63d that are the opposing parts of adjacent linear slits, that is, sandwiched by adjacent linear slits.

[0041] According to the steam release part 4c configured in this way, when the internal pressure of the container V increases, the lifting part 5c moves upward. One end of each of the four bridge-shaped parts 63a to 63d is connected to the outer periphery of the substantially disk-shaped lifting part 5c at a predetermined interval (90 degrees), and the other end is connected to the bottom surface 25a of the concave part 25. The four bridge-shaped parts 63a to 63d function such that the lifting part 5c moves upward corresponding to the internal pressure of the container while being in a substantially parallel state with respect to the bottom surface 25a of the concave part 25. Similar to the first embodiment, the lifting part 5c moves upward when the internal pressure of the container V increases and moves downward when the internal pressure decreases. When the internal pressure of the container becomes atmospheric pressure, the lifting part 5c and the bridge-shaped parts 63a to 63d come to be located in the same plane as the bottom surface 25a of the concave part 25.

[0042] Fig. 7 shows a perspective view showing a state where steam is ejected from the steam release part 4c. When the internal pressure of the container V reaches a predetermined pressure, the lifting part 5c moves upward while maintaining a substantially parallel state with respect to the bottom surface 25a of the concave part 25 by the bridge-shaped parts 63a to 63d. Thereby, an opening 80 is formed between the bottom surface 25a of the concave part 25 and the lifting part 5c. Ignoring the thickness of the bridge-shaped parts 63a to 63d, the opening 80 opens over the entire circumference between the bottom surface 25a of the concave part 25 and the lifting part 5c, and it becomes possible to efficiently release the steam inside the container to the outside with a smaller formation area compared to the conventional linear opening. Also, when the internal pressure of the container increases, the lifting part 5c moves further upward, the opening area between the lifting parts 63a to 63d and the bottom surface 25a of the concave part 25 increases, and the release of the steam inside the container V is further promoted.

[0043] The number of formed linear slits may be two or more, and in the case of this embodiment, it is preferably three or more. As described above, it is preferable from the viewpoint of efficient steam release that the lifting part 5c moves upward and is held in a substantially parallel state with respect to the bottom surface 25a of the concave part 25. When there are two linear slits, the bridge-shaped parts supporting the lifting part 5c are formed only at two opposite positions of the lifting part 5c, and it is difficult to maintain the parallel state of the lifting part 5c. On the other hand, if there are three or more linear slits, since the bridge-shaped parts supporting the lifting part 5c are formed at three or more positions, the parallel state of the lifting part 5c is stably maintained.

[0044] The preferred ranges of the length L of the linear slit, the length N of each opposing portion of adjacent linear slits, and the distance D between opposing linear slits are exemplified in the first embodiment and are also applicable here.

[0045] (Modification 2) FIG. 8 shows a plan view of a modification of the steam release portion, and FIG. 9 shows a perspective view of a state in which steam is ejected from the steam release portion 4d. The steam release portion 4d shown in these figures is the same as the steam release portion 4c of the second embodiment in that four semi-circular arc-shaped linear slits 44a to 44d are arranged to form an annular shape. However, in this modification, both ends in the extending direction of the linear slits 44a and 44c are located outside the annular shape with respect to the ends in the extending direction of the adjacent linear slits 44b and 44d. In other words, both ends in the extending direction of the linear slits 44b and 44d are located inside the annular shape with respect to the ends in the extending direction of the adjacent linear slits 44a and 44c.

[0046] Even in the steam release portion 4d having such a configuration, when the internal pressure of the container V increases, the lifting portion 5d moves upward. The bridge-shaped portions 64a and 64b and the bridge-shaped portions 64c and 64d connect the opposing portions of the lifting portion 5d and the bottom surface 25a of the concave portion 25, and function so that the lifting portion 5d moves upward corresponding to the internal pressure of the container in a state substantially parallel to the bottom surface 25a of the concave portion 25.

[0047] However, in the steam release portion 4d composed of four linear slits 44a to 44d as in this modification, the lifting portion 5d is supported by the bridge-shaped portions 64a and 64b and the bridge-shaped portions 64c and 64d at two opposing locations. Therefore, it may be difficult to stably support the lifting portion 5d in a state substantially parallel to the bottom surface 25a of the concave portion 25. In order for the lifting portion 5d to be stably supported in a substantially parallel state, it is preferable that the lifting portion 5d is supported by bridge-shaped portions at at least three locations. In this case, the number of linear slits required is six or more.

[0048] The preferred ranges of the length L of the linear slit, the length N of each opposing portion of adjacent linear slits, and the distance D between opposing linear slits are exemplified in the first embodiment and are also applicable here.

[0049] (Others) In the embodiments described above, the steam release portion was formed on the bottom surface 25a of the recess 25 formed in the top wall 21 of the lid body 2. However, the formation location of the steam release portion is not particularly limited. It may be formed on the top wall 21 of the lid body 2 without the recess 25, or may be formed on the outer peripheral wall 22. Also, there is no limitation on the number of formed steam release portions, and of course, two or more may be provided. The shape of the lid body is not limited to that of the above embodiment, and any shape that can seal the opening of the container body 1 is acceptable.

[0050] (Experimental Example 1) In the steam release portion having the configuration shown in FIG. 2, the length N of the opposing portion of the linear slits was changed every 2 mm from 2 mm to 16 mm, and the distance D between the opposing linear slits was changed every 2 mm from 2 mm to 10 mm. A steam release portion with a changed ratio of the length N to the length of the linear slits and a changed ratio of the distance D was formed on the lid body, and the pushing force (N) when the lifting portion of the steam release portion was pushed in by 2 mm using a push-pull gauge was measured. The measurement results are shown in Table 1.

[0051] (Experimental Example 2) In the steam release portion having the configuration shown in FIG. 6, the length N of the opposing portion of the linear slits was changed every 2 mm from 2 mm to 12 mm, and the distance D between the opposing linear slits was changed every 2 mm from 2 mm to 6 mm. A steam release portion with a changed ratio of the length N to the length of the linear slits and a changed ratio of the distance D was formed on the lid body, and the pushing force (N) when the lifting portion of the steam release portion was pushed in by 2 mm using a push-pull gauge was measured. The measurement results are shown in Table 2.

[0052] [Table 1]

[0053] [Table 2]

[0054] As is clear from Tables 1 and 2, also in the steam release portions shown in FIGS. 2 and 6, the smaller the ratio of the length N of the opposing portion of the linear slit to the length of the linear slit and the smaller the ratio of the distance D between the opposing linear slits to the length of the linear slit, the weaker the pushing force. That is, it was found that the larger the ratio of the length N and the smaller the ratio of the distance D, the more the steam release portion can operate even at a low container internal pressure.

Industrial Applicability

[0055] In the lid according to the present invention, since the amount of steam released per formation area of the steam release portion is larger than before, the formation area of the steam release portion can be made smaller than before. Further, the steam discharge portion can operate even when the container internal pressure is relatively small. And also, the steam discharge portion can surely maintain a closed state in a non-heated state (under atmospheric pressure).

Explanation of Signs

[0056] 1 Container body 2 Lid 4a, 4b, 4c, 4d Steam release portion D Width of opposing portion of linear slit L Length of linear slit N Length of each opposing portion of linear slit V Container 41a~41d Linear slit 42a~42d Linear slit 43a~43d Linear slit 44a~44d Linear slit 5a, 5b, 5c, 5d Lifting portion 61a~61b Bridge portion 62a~62b Bridge portion 63a~63b Bridge portion 64a~64b Bridge portion 80 Opening

Claims

Claim 1 A lid for a container that is cooked by heating in a microwave oven, having a steam release portion formed such that two or more linear slits form one annular shape, wherein both ends in the extending direction of each of the two or more linear slits face each other with a predetermined distance in the radial direction from the ends in the extending direction of the linear slits adjacent in the circumferential direction, the steam release portion is composed of a lifting portion surrounded by a portion located inside the two or more linear slits and a bridge portion sandwiched between portions facing each other in the radial direction of the linear slits adjacent in the circumferential direction, the bridge portion enables the lifting portion to move upward in response to an increase in the internal pressure of the container, and the lifting portion moves upward when the internal pressure of the container increases A lid for a container for microwave cooking, characterized by the above. Claim 2 The lid for a container for microwave cooking according to claim 1, wherein the length of each of the opposing portions of the linear slits is 10% or more and 50% or less of the length of the linear slits located outside the annular shape in the opposing portion. Claim 3 The lid for a container for microwave cooking according to claim 1 or 2, wherein the distance between each of the opposing linear slits is 25% or less of the length of the linear slits located outside the annular shape in the opposing portion. Claim 4 The lid for a container for microwave cooking according to any one of claims 1 to 3, wherein one end in the extending direction of each of the two or more linear slits is located inside the annular shape compared to the ends in the extending direction of the adjacent linear slits, and the other end in the extending direction is located outside the annular shape compared to the ends in the extending direction of the adjacent linear slits. Claim 5 The lid for a container for microwave cooking according to claim 4, wherein the steam release portion is formed such that three or more of the linear slits form one annular shape. Claim 6 The lid for a container for microwave cooking according to any one of claims 1 to 3, wherein both ends in the extending direction of each of the two or more linear slits are located either inside or outside the annular shape compared to the ends in the extending direction of the adjacent linear slits. Claim 7 The lid for a container for microwave cooking according to claim 6, wherein the steam release portion is formed such that six or more of the linear slits form one annular shape. Claim 8 The lid for a container for microwave cooking according to any one of claims 1 to 6, wherein the length of one linear slit is 5 mm or more and 40 mm or less. Claim 9 The lid of the container for electronic range cooking according to any one of claims 1 to 8, wherein the annular shape formed by the two or more linear slits is a square shape or a circular shape.

10. The lid of the container for electronic range cooking according to claim 9, wherein the two or more linear slits have the same shape and a shape in which the middle part of the straight line is bent.

11. The lid of the container for electronic range cooking according to claim 9, wherein the two or more linear slits have the same arc shape.

Images