JPH03200574A - Heating vessel of electronic oven - Google Patents

Abstract

PURPOSE:To prevent the contents from leaking out during the operation of an electronic oven by providing a drop-in section on the inner surface of a vessel and providing a small gap between the vessel and a flange of an over cap. CONSTITUTION:When a vessel 1 is sealingly closed by an inner lid 3, a drop-in section 8 makes contact with the inner lid 3, so that an over cap 2 is fixed to the vessel by means of an auxiliary fixing wall 14 of the cap 2. When the heating vessel of an electronic oven is heated, the inner lid is removed and hence the section 8 of the cap comes into the vessel so that the outer periphery of the drop-in section comes into contact with the upper inner periphery of the vessel. A protrusion 10 projected from the inner side of a flange 9 of the cap contacts a flange of the vessel to define a non-capillary gap 18 therebetween. An engaging protrusion 12 provided near the end of the cap contacts an engaging protrusion 7 provided near the end of an outer wall 6 of vessel to fix the cap to the vessel, while steam is discharged from a steam outlet 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a container in which the contents do not ooze out from the gap between the container and the overcap when heated in a microwave oven.

[Prior Art] Conventional containers are heated in a microwave oven after the inner lid of the container containing the contents is removed and an overcap is placed on the container. However, when heated in a microwave oven, the contents enter the contact area of the overcap container, which not only greatly deteriorates the appearance, but also often prevents the overcap from flowing out. However, this phenomenon could not be prevented.

Moreover, not only is it very dirty, but the container is also dirty and difficult to handle, and a solution to this problem has been desired.

[Problems to be Solved by the Invention] The present invention solves the problem of the contents entering the contact area between the overcap and the container, causing deterioration in appearance and flowing out, which occur when heated in a microwave oven. The purpose of the present invention is to provide a container that can be easily and safely heated in a microwave oven.

[Means for solving the problems] The present invention has the following features: r1. A. A plastic container having a flange formed by bending the upper wall of the container outward; B. A central portion with a diameter smaller than the diameter of the opening of the container, and a peripheral portion thereof having a U-shaped cross section. A drop-in part whose outer circumferential wall formed by bending is in close contact with the upper wall of the container, a flange part formed by bending the peripheral edge of the drop-in part outward, and a flange part formed by bending the outer peripheral edge of the flange part downward. The overcap consists of a plastic overcap having a fixed wall portion, and an isolation member provided between the C0 container and the flange of the overcap or beyond the flange, and when the overcap is placed on the container, the A container for heating in a microwave oven, characterized in that a non-capillary gap is formed between a flange portion and a flange portion of an overcap.

2. The microwave heating container according to claim 1, wherein the container has an outer wall portion formed by bending the outer peripheral edge of the flange portion downward.

3. The microwave heating container according to claim 1 or 2, wherein the container has an outwardly projecting protrusion formed on its outer wall.

4. The microwave heating container according to any one of claims 1 to 3, wherein the container has an outwardly projecting overcap locking protrusion near the tip of the outer wall.

5. Any one of claims 1 to 4, wherein the container has a projection projecting upward on the upper surface of the flange portion thereof.
Containers for heating in a microwave oven as described in section.

6. The microwave heating container according to any one of claims 1 to 5, wherein the upwardly protruding projection disposed on the upper surface of the flange portion of the container is a continuous ring-shaped projection or a discontinuous projection.

7. Claim 1, wherein the overcap is an overcap having a locking protrusion protruding inwardly formed on its fixed wall.
A container for heating in a microwave oven according to any one of items 6 to 6.

8. Claim 1, wherein the overcap is an overcap in which a protrusion protruding inward is formed at the lower end of the fixed wall.
A container for heating in a microwave oven according to any one of items 7 to 7.

9. The microwave oven heating according to any one of claims 1 to 8, wherein the overcap is an overcap in which an auxiliary fixing wall section is provided with a locking protrusion projecting inward at the lower end of the fixing wall. container.

10. The overcap is an overcap having a protrusion projecting downward on the lower surface of its flange;
A microwave heating container according to any one of claims 1 to 9.

11. There are 3 protrusions that protrude downward located on the underside of the flange of the overcap! The microwave heating container according to any one of claims 1 to 10, wherein the container has continuous ring-shaped projections or discontinuous projections.

12. The container for heating in a microwave oven according to any one of claims 1 to 7, wherein the isolating material is a protrusion protruding outwardly provided on a flange portion or an outer wall of the container.

13. The microwave heating container according to claim 1, wherein the separating member is a protrusion protruding inwardly provided on the flange portion of the overcap or the outer wall of the fixed wall.

14. Interval! According to claim 1, the If material is a locking protrusion provided on the fixed wall of the overcap and protruding inwardly, or an overcap locking protrusion provided protruding outward near the tip of the outer wall of the container. Container for microwave heating.

15. The microwave heating container according to claim 1, wherein the non-capillary gap is a gap formed by an upwardly protruding protrusion provided on the upper surface of the flange portion of the container and abutting against the lower surface of the flange of the overcap.

16. The non-capillary gap connects at least the overcap flange portion and the container flange portion by bringing the outwardly protruding protrusion of the outer wall of the container into contact with the fixed wall of the overcap.
The microwave heating container according to claim 1, wherein the gap is formed at a distance of A.

17. The microwave heating container according to claim 1, wherein the non-capillary gap is a gap formed by a downwardly protruding protrusion provided on the lower surface of the flange of the overcap and in contact with the upper surface of the flange portion of the container.

18. I' in which the non-capillary gap is formed by making an inwardly protruding locking protrusion provided on the fixed wall of the overcap contact the outer wall of the container to separate at least the overcap flange portion and the container flange portion; The microwave heating container according to claim 1, which has a 1 liter gap.

19. The non-capillary gap engages an inwardly protruding locking protrusion in the fixed mold of the overcap with an outwardly protruding overcap locking protrusion provided near the tip of the outer wall of the container, so that at least the overcap flange The container for heating in a microwave oven according to claim 1, wherein a gap is formed to separate the flange portion of the container from the flange portion of the container.

20. The microwave oven according to any one of claims 1 to 19, wherein the width of the non-capillary gap is two or more widths from the inner circumferential surface of the upper wall of the container to which the outer circumferential wall of the drop-in portion of the overcap is in close contact. Heating container.

21. The microwave heating container according to any one of claims 1 to 20, wherein the container and the overcap are made of waterproof paper or plastics.

In the present invention, the container is provided with a flange portion around the opening. The flange portion of the overcap contacts this flange portion to seal the inside.

A continuous ring-shaped protrusion or a discontinuous protrusion that protrudes upward can be provided on the flange portion. As will be explained in detail later, this protrusion abuts the flange portion of the overcap to form a non-capillary gap between the two flange portions.

Further, the outer peripheral edge of the flange portion of the container is bent downward to form a cap on the outside. When the overcap is put on, the outer wall portion and the fixing wall of the overcap come into contact and the overcap is fixed.

An outwardly projecting overcap locking protrusion may be formed near the tip of the outer wall of the container.

The overcap is provided with a drop-in portion formed by bending the peripheral edge of the center portion into a U-shape in cross section and having a diameter smaller than the opening diameter of the container.

When heating in a microwave oven, first remove the inner lid of the container and cover it with this overcap.At this time, if the outer circumferential wall of the drop-in part of the overcap is on the inner circumferential wall above the container, for example, if the container has a cooking line, this is the case. Seal the container by touching the upper inner periphery.

Therefore, it is necessary for this drop-in part to have an outer circumferential wall that tightly contacts the upper inner periphery of the container, and in the present invention, the drop-in part formed by bending the peripheral edge of the center part into a U-shape in cross section is It is to be understood that this includes all drop-in portions having an outer circumferential wall that is in close contact with the upper inner periphery of the container, such as a V-shaped cross section, an N-shaped cross section, an M-shaped cross section, etc.

In addition, the overcap is provided with a flange portion formed by bending the peripheral edge of the drop-in portion outward.
When the overcap is placed on the container, the flange portion of the container and the flange portion of the overcap are placed opposite each other.

The flange of the overcap has a continuous ring-shaped protrusion that protrudes downward. F! A continuous projection can be provided. As will be explained in detail later, this protrusion abuts the flange portion of the container to form a non-capillary gap between the two flange portions.

The outer peripheral edge of the flange portion of the overcap is bent downward to form a fixed wall. As mentioned above, when the overcap is placed on the container, the outer wall of the container and the fixing wall of the overcap come into contact and the overcap is fixed.

The fixed wall can be provided with inwardly projecting continuous ring-shaped or discontinuous projections.

As will be explained in detail later, this protrusion can come into contact with the outer wall of the container to form a non-capillary gap therebetween.

By arranging a locking protrusion projecting inward at the lower end of the fixed wall, the locking with the outer wall of the container is improved.

An auxiliary fixed wall can be connected to the lower end of the fixed wall of the overcap.

Some containers are covered with an inner lid, and an overcap is placed on top of the inner lid and placed on the container during the distribution process, but since the overcap in the present invention has a special structure of a dropping part, it is not necessary to provide an auxiliary fixing wall. In the case of a container with an inner lid, it is not possible to put an overcap over it, so in this case, it is desirable to arrange an auxiliary fixing wall that is longer than the drop-in part.

By arranging a locking protrusion projecting inward at the lower end of the auxiliary fixing wall, the locking with the outer wall of the container can be improved.

The isolation member is located between or beyond the seven langes of the container and overcap. As mentioned above, this member is a protrusion placed on the 7 lunges of the container and the overcap, or on the outer wall of the container or the fixed wall of the overcap, but it may be integrally formed or a block body such as a separately manufactured rod shape is placed. It may also be formed by bending the flange or wall of the corresponding portion of the container or overcap.

These protrusions may be continuous ring-shaped protrusions or discontinuous protrusions, or both may be used in combination.In addition, these protrusions may be inwardly protruding locking protrusions provided on the fixed wall of the overcap, or may be discontinuous protrusions. An overcap locking protrusion provided protruding outward near the tip of the outer wall of the overcap may be used to function.

Further, it is preferable that the overcap is provided with a steam hole for discharging steam during heating.

As can be understood from the foregoing description, one of the important features of the present invention is that when the inner lid of the container is removed and the overcap is placed on the container, the space between the two opposing flanges may be further removed. A non-capillary gap is also provided between the outer wall and the fixed wall of the overcap.

A non-capillary gap is necessarily formed at least between the opposing flanges of the container and the overcap by the above-mentioned separating member, but there is also an overcap locking projection protruding outward near the tip of the outer wall of the container. , the inwardly protruding stop protrusion is brought into contact with the lower end of the fixed wall of the overcap, and the non-hair MA'! It is okay to form a gap.

Alternatively, a projection may be provided on either or both of the outer portion of the container and the fixed wall of the overcap to form a non-capillary gap between the flanges and between the outer wall of the container and the fixed wall of the overcap. good.

Since capillarity has a large relationship with the surface tension of liquid components, the size of the non-capillary gap to be arranged is determined by the surface tension of the contents. More specifically, this will be explained in the Examples section.

Effectively, the non-capillary gap exists between seven flange portions with a width of 2IllI or more from the inner circumferential surface above the cooking line of the container.

[Function] When a conventional microwave heating container is actually heated in a microwave oven, the contents enter the gap between the flange around the opening of the container and the flange of the overcap, and even flow out. It looks dirty and has the disadvantage of being difficult to handle.

As a result of various studies on the causes of the above-mentioned oozing, the present inventors have discovered that the cause is heating of solid components stored in containers made of waterproof paper, plastics, etc.

The inventor of the present invention considers the following as to why such a phenomenon occurs when a liquid component and a solid component coexist.

Even when only a liquid component is contained, when heated in a microwave oven, the electric field generated by the microwave becomes very strong at the bottom, so the liquid component at the bottom is heated strongly. However, since it is a liquid, convection occurs and heat conduction occurs smoothly, so there is no bumping and no large impact occurs.

However, when a liquid component and a solid component coexist, the liquid component and solid component at the bottom are heated strongly, similar to heating in a microwave oven. Unlike the liquid component, the heat of the solid component can only be transferred to other parts by conduction, so it is difficult to diffuse the heat of the solid component smoothly.

As a result, the temperature of the solid component at the bottom rises rapidly, so that the liquid contained in the solid component at the bottom rapidly vaporizes and the solid component ruptures.

Especially lightweight containers can jump up to nearly 1100a.

This impact causes the overcap to bulge upwards,
The flange at the periphery of the container opening, which had been kept in a closed room, and the flange of the overcap separate, creating a gap into which the boiling contents flow.

Surprisingly, at this time, the liquid component in the upper part is still sufficiently heated and has a temperature of about 50 to 60 DEG C. at most.

The problem is that when heating in a microwave oven, most of the contents of the container are separated into solid and liquid components. Therefore, it is well understood how the problems to be solved by the present invention are desired to be solved.

The occurrence of such non-uniform heating will be explained with reference to FIG.

Figure 5 shows a plastic cup-shaped container with a bottom diameter of 47-1 and a height of 100 m containing corn soup (solid matter:
The temperature-time curves of liquid and solid matter are shown when filled with 7-76 wt%) and heat-treated in a microwave oven (NE-M340.500W glass turntable manufactured by Matsushita Electric Industrial Co., Ltd.). For example, when the temperature of the liquid is 38°C after 20 seconds, the temperature of the solids is 100°C, and when the temperature of the liquid is 50°C after 40 seconds, the temperature of the solids is 120"C, and the water in the solids rapidly evaporates and becomes solid. It is understood that things will burst. Next, the relationship between heating temperature and time depending on the position in the container is shown for some 8i solids. The liquid is water.

Table 1 From these test results, it is understood that when liquid contents containing solids are heated in a microwave oven, bumping occurs which causes a large impact.

In order to solve this problem, the inventor of the present invention improved the structure of the overcap and tried to strengthen the adhesion between the container and the overcap. In other words, a center part with a diameter smaller than the diameter of the opening of the container and an outer circumferential wall formed by bending the peripheral part into a U-shape in cross section are arranged in the upper part of the container, such as a cooking line. For example, an attempt has been made to arrange a drop-in portion that is in close contact with the wall portion above this so that the inner surface of the container and the outer circumferential surface of the drop-in portion come into close contact with each other to prevent the flange of the container from separating from the flange of the overcap.

This structure greatly improves the adhesion between the container and the overcap. However, when this container was heated in a microwave oven, the contents oozed out between the flange of the container and the flange of the overcap, and this could not be prevented.

As a result of further research, the present inventor found that by providing a drop-in part, the adhesion against the upward bulge of the overcap due to the fII impact caused by the rupture of the solid component was improved, so that peeling between the overcap and the flange was improved. It was found that the slight peeling that occurs forms a capillary gap, which causes the contents to be sucked up by capillary action, causing oozing.

The inventor has conducted various studies and found that W caused by the rupture of solid components
It was found that the occurrence of the capillary MJ tube gap cannot be completely prevented if the container and overcap are made of fatty paper, plastics, etc. due to the large I impact. Therefore, we considered and researched ways to prevent the contents from being sucked up by capillary action by allowing the generation of capillary gaps. When the overcap was placed on the container, a gap was created in advance between the container and the flange of the overcap in which capillary action could not occur. Although this gap may widen due to the impact caused by the rupture of the solid component, a separating member is placed between the container and the overcap to ensure a gap so that it does not narrow to form a capillary gap.

The gap is provided between the container and the flange of the overcap, but may also extend between the outer wall of the container or the fixed wall of the overcap.

This attempt goes against the conventional wisdom of sealing the container to prevent oil leakage.

However, in an experiment, oozing was completely prevented, contrary to expectations.

The non-capillary gap has little effect unless it exists with a width of 2+n+ or more from the inner circumferential surface of the opening of the container, which is in contact with the outer circumference of the drop-in portion of the overcap.

One of the features of the present invention is that in order to prevent the contents from seeping out, the usual sealing is omitted, and instead a gap is provided.

The present invention solves the problem of the contents of the container oozing out when heated in a microwave oven.

[Example〕 Next, the present invention will be specifically explained using examples.

Figure 1 shows a microwave oven heating container according to an embodiment of the present invention.
Part l! FIG. This container is shown before being heated in the microwave.

1 is a container whose opening is sealed with a middle 113. 4
is the upper circumferential wall of the container, and in this embodiment a stacking line 15 is provided. Reference numeral 5 denotes a flange portion formed by bending the upper peripheral wall 4 of the container outward. Middle school 113 here
is removably fixed. Reference numeral 6 denotes an outer wall formed by bending the outer peripheral edge of the flange downward. Reference numeral 7 denotes an overcap locking projection protruding near the tip of the outer wall. Although not shown, the flange and the outer wall may be provided with outwardly projecting projections that form a non-capillary gap.

Reference numeral 2 designates an overcap, which is provided with a drop-in portion 8 formed by bending the peripheral edge of a central portion 16 in which a steam exhaust hole 17 is provided into a U-shaped cross section. Reference numeral 9 denotes a flange portion formed by bending the outer peripheral edge of the drop-in portion outward. 10 is a protrusion provided on the flange portion that protrudes inward, and forms a non-capillary gap between the protrusion 10 and the flange portion of the container. 11 is a fixed wall of the overcap, and 12 is a locking projection protruding near the tip of the fixed wall. Reference numeral 14 denotes an auxiliary fixing wall disposed at the tip of the fixing wall, and since the drop-in part contacts the inner lid while the container is sealed with the inner lid 113, the overcap is fixed to the container by this auxiliary fixing wall. . Reference numeral 13 denotes a locking projection protruding near the tip of the auxiliary fixing wall. Although not shown, the fixing wall of the overcap can be provided with inwardly projecting protrusions that form a non-capillary gap.

FIG. 2 is a partial longitudinal sectional front view showing the microwave oven heating container according to the embodiment of the present invention shown in FIG. 1 during heating.

It can be seen that the inner lid has been removed and the drop-in portion 8 of the overcap has been fitted into the container, with the outer peripheral edge of the drop-in portion being in contact with the upper inner peripheral surface of the container.

An inwardly protruding protrusion 10 provided on the flange 9 of the overcap contacts the flange of the container, and a non-capillary rWJ gap 18 is formed between the flange and the flange of the container. The overcap is fixed to the container by a locking protrusion 12 protruding near the tip of the fixing wall abutting an overcap locking protrusion 7 protruding near the tip of the outer wall 6 of the container. is understood. Steam generated during heating is discharged to the outside from the steam exhaust hole I7.

FIG. 3 is a partially longitudinal sectional front view showing another embodiment of the microwave oven heating container during heating.

It can be seen that the inner lid has been removed and the drop-in portion 8 of the overcap has been fitted into the container, with the outer peripheral edge of the drop-in portion being in contact with the upper inner peripheral surface of the container.

A protrusion 19 provided on the flange 5 of the container and projecting outward abuts against the flange of the container, forming a non-capillary gap jJt18 between the flange and the flange of the container.

FIG. 4 is a partial msi front view showing another embodiment of the microwave oven heating container during heating.

It can be seen that the inner lid has been removed and the drop-in portion 8 of the overcap has been fitted into the container, with the outer peripheral edge of the drop-in portion being in contact with the upper inner peripheral surface of the container.

In this embodiment, a locking protrusion 12 protruding near the tip of the fixed wall of the overcap is attached to the outside of the container. It is fixed to the container by coming into contact with an overcap locking projection 7 protruding near the tip of the overcap 6, and a non-capillary gap 18 is formed between the cap and the flange of the container.

Next, Table 2 shows the trial results of the present invention.

(The following is a blank space) [Effects] As is clear from the above test results, it is understood that the container of the present invention has an excellent effect in that there is no leakage to the flange due to electronic heating.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a portion of the container of the present invention before heating. FIG. 2 is a front sectional view of a portion of the container of the present invention during heating. FIG. 3 is a front cross-sectional view of a portion of the container of the present invention, which does not show the non-capillary gap formed between the flange of the overcap and the flange of the container during heating. FIG. 4 is a front sectional view of a portion of another embodiment of the container according to the present invention, which does not show the non-capillary gap formed between the flange portion of the overcap and the flange portion of the container during heating. FIG. 5 is a graph showing temperature changes due to heating of contents. 1... Container 2... Overcap 3... Inner lid 4... Container upper peripheral wall 5... Container flange 6... Container outer wall 7... Overcap locking protrusion 8... - Dropping part 9...Flange 10 of the overcap...Protrusion 11 of the flange of the overcap...
- Fixing wall 12 of the overcap...Locking protrusion 13 of the fixing wall...Locking protrusion 14 of the auxiliary fixing wall...Auxiliary fixing wall 15...Stacking line 16...Central part 17 of the overcap ...Steam hole 18...Non-capillary gap 19...Protrusion on the flange of the container Fig. 1 Fig. 2 Fig. 5 120 00 80 60 Temperature (''C) 0 0

Claims (1)

[Claims] 1. A. A plastic container having a flange formed by bending the upper wall of the container outward; B. A central portion having a diameter smaller than the diameter of the opening of the container; a drop-in portion whose outer circumferential wall is formed by bending the peripheral edge into a U-shape in cross section and is in close contact with the upper wall of the container; a flange portion formed by bending the peripheral edge of the drop-in portion outward; A plastic overcap having a fixed wall portion formed by bending the outer periphery downward; C. A separating member provided between the container and the flange portion of the overcap or beyond the flange portion; A container for heating in a microwave oven, characterized in that, when covered with a cap, a non-capillary gap is formed between a flange portion of the container and a flange portion of an overcap. 2. The microwave heating container according to claim 1, wherein the container has an outer wall portion formed by bending the outer peripheral edge of the flange portion downward. 3. The microwave heating container according to claim 1 or 2, wherein the container has an outwardly projecting protrusion formed on its outer wall. 4. The microwave oven heating container according to any one of claims 1 to 3, wherein the container has an outwardly projecting overcap locking protrusion formed near the tip of the outer wall. 5. The microwave heating container according to any one of claims 1 to 4, wherein the container has a projection projecting upwardly on the upper surface of the flange portion thereof. 6. The upwardly protruding protrusion provided on the upper surface of the flange of the container is a continuous ring-shaped protrusion or a discontinuous protrusion;
A microwave heating container according to any one of claims 1 to 5. 7. The microwave heating container according to any one of claims 1 to 6, wherein the overcap is an overcap having a locking protrusion projecting inwardly formed on its fixed wall. 8. The microwave heating container according to any one of claims 1 to 7, wherein the overcap is an overcap having a protrusion projecting inwardly formed at the lower end of the fixed wall. 9. Microwave oven heating according to any one of claims 1 to 8, wherein the overcap is an overcap in which an auxiliary fixed wall section is provided with a locking protrusion projecting inward at the lower end of the fixed wall. container. 10. The microwave heating container according to any one of claims 1 to 9, wherein the overcap is an overcap having a projection projecting downward on the lower surface of the flange. 11. The microwave heating container according to any one of claims 1 to 10, wherein the downwardly protruding protrusion provided on the lower surface of the flange of the overcap is a continuous ring-shaped protrusion or a discontinuous protrusion. . 12. Any one of claims 1 to 7, wherein the isolating material is an outwardly protruding protrusion provided on the flange portion or outer wall of the container.
Containers for heating in a microwave oven as described in Section 1. 13. Claim 1, wherein the separating member is a protrusion protruding inwardly provided on the flange portion of the overcap or the outer wall of the fixed wall.
A container for heating in a microwave oven as described in . 14. Claim 1, wherein the separating material is an inwardly protruding locking protrusion provided on the fixed wall of the overcap, or an overcap locking protrusion protruding outwardly near the tip of the outer wall of the container. Container for microwave heating. 15. The microwave heating container according to claim 1, wherein the non-capillary gap is a gap formed by an upwardly projecting protrusion provided on the upper surface of the flange portion of the container abutting against the lower surface of the flange of the overcap. 16. Claim 16, wherein the non-capillary gap is a gap formed by making an outwardly projecting protrusion of the outer wall of the container abut against a fixed wall of the overcap, separating at least the overcap flange and the container flange. 1. The microwave heating container described in 1. 17. The microwave heating container according to claim 1, wherein the non-capillary gap is a gap formed by a downwardly protruding protrusion provided on the lower surface of the flange of the overcap and in contact with the upper surface of the flange portion of the container. 18. The non-capillary gap is a gap formed by separating at least the overcap flange portion and the container flange portion by abutting the inwardly protruding locking protrusion provided on the fixed wall of the overcap against the outer wall portion of the container. A microwave heating container according to claim 1. 19. The non-capillary gap engages an inwardly protruding locking protrusion on the fixed wall of the overcap with an outwardly protruding overcap locking protrusion near the tip of the outer wall of the container, so that at least the overcap flange 2. The microwave heating container according to claim 1, wherein the gap is formed by separating the container flange and the container flange. 20. Microwave heating according to any one of claims 1 to 19, wherein the width of the non-capillary gap is 2 mm or more from the inner circumferential surface of the upper wall of the container to which the outer circumferential wall of the drop-in portion of the overcap is in close contact. container. 21. Any one of claims 1 to 20, wherein the container and the overcap are made of waterproof paper or plastics.
Containers for heating in a microwave oven as described in section.