JP4349975B2 - Microwave oven heating container and microwave oven packaging food - Google Patents

Description

  The present invention includes a microwave heating container which is a double container in which an outer container made of a thermoplastic resin foam molded body and an inner container made of a thermoplastic resin sheet molded body are combined, and food is contained in the inner container. The present invention relates to a packaged food for heating a microwave oven.

Conventionally, as a microwave packaging container that can be cooked as it is with a microwave oven, for example, techniques described in Patent Documents 1 to 3 have been proposed.
Patent Document 1 provides a skirt portion that hangs down from the upper end of the peripheral wall of the inner container body with a gap from the peripheral wall, a first collar portion is provided on the outer periphery of the lower end of the skirt portion, and the upper end outer periphery of the peripheral wall of the outer container body. A second collar portion corresponding to the first collar portion is provided, and outer peripheries of the first and second collar portions are engaged with each other, and a bottom wall and a peripheral wall of the inner container body, and the outer container There is disclosed a microwave oven container in which a predetermined gap is formed between a bottom wall and a peripheral wall of a main body.
Patent Document 2 discloses a container for a microwave oven including an inner container and an outer container, and having a space between the inner container and the outer container.
Patent Document 3 discloses a double container comprising an outer container and an inner container, the outer container comprising a container molded from a thermoplastic foam resin sheet, and the inner container being a container molded from a heat-resistant non-foamed resin sheet. The inner container is inserted into the outer container and combined with the outer container and the inner container between the outer container and the inner container in a state where an air space is formed at least between the bottom surfaces. A synthetic resin double container is disclosed.
Japanese Patent Laid-Open No. 11-56621 Japanese Utility Model Publication No. 4-11307 Utility Model Registration No. 3023900

However, the above-described conventional technique has the following problems.
In the container disclosed in Patent Document 1, the bottom of the inner container has a flat bottom shape. When food is put in the inner container and cooked in a microwave oven, it is difficult to convect in the inner container even if the liquid component is heated. Due to the structure, there are problems in that the heating efficiency is poor and uneven temperature distribution tends to occur in each part.
In addition, the container disclosed in Patent Document 2 has a round bottom at the bottom of the inner container so as to be particularly suitable for cooked rice, but since the inner container has a round bottom, the bottom is microwaved. Is difficult to reach, the surface layer becomes hot, but the bottom does not warm, etc.
In the container disclosed in Patent Document 3, a step portion is formed on the inner side of the outer container, an edge portion that can be placed on the step portion is formed on the outer periphery of the inner container, and the inner container is inserted into the outer container. Because it is a combination, the mouth of the inner container is below the upper end of the outer container, so that you can not drink liquids such as soup in the inner container, it contains liquids such as noodles, soup, soup Not suitable for.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a container for heating a microwave oven and a packaged food for heating a microwave oven in which contents contained in an inner container can be efficiently and uniformly heated during cooking with a microwave oven.

In order to achieve the above object, the present invention comprises an outer container made of a thermoplastic resin foam molded article, and an inner container made of a thermoplastic resin sheet molded article and placed in the outer container. Provided at the bottom is a convex portion that gradually bulges upward from the periphery of the bottom toward the center, and a groove for the inner container is provided.
In the microwave oven heating container of the present invention, it is preferable that the protrusion height of the protrusion is 4 mm to 30 mm, and the minor axis of the protrusion horizontal section at a height of 4 mm is in the range of 5 mm to 80 mm.
In the microwave oven heating container of the present invention, it is preferable that a large number of the grooves extend from the upper part of the side wall part of the inner container toward the convex part.
In the microwave heating container of the present invention, it is preferable that the groove has a spiral shape at the bottom surface of the inner container.
In the microwave heating container of the present invention, it is preferable that the groove is provided up to the top of the convex portion.
In the microwave oven heating container of the present invention, it is preferable that the groove is provided up to the skirt of the convex portion.
In the microwave heating container of the present invention, it is preferable that a horizontal portion is provided on the top of the convex portion.

In addition, the present invention provides a packaged food for heating a microwave oven, wherein the food is stored in the inner container of the aforementioned microwave heating container according to the present invention, and the lid is fitted to the inner container and packaged. To do.
In the packaged food for microwave heating according to the present invention, the food is preferably prepared such that the liquid component is solidified with a food solidifying agent and the liquid component can be melted when heated.

A container for heating a microwave oven according to the present invention has an outer container made of a thermoplastic resin foam molded article, and an inner container made of a thermoplastic resin sheet molded article and put in the outer container, and the bottom of the inner container In addition, a convex portion that gradually bulges upward from the periphery of the bottom toward the center is provided, and a groove is provided in the inner container, so that food containing a large amount of liquid components is contained in the inner container and cooked in a microwave oven. In this case, the upper part of the convex part is warmed, it flows toward the side wall part, and further sinks underneath, so that the liquid tends to cause convection, so that the heating efficiency is improved and the entire contents can be heated uniformly. it can. In addition, when food with relatively low water content such as rice or pasta is stored in the inner container and cooked in a microwave oven, the water that oozes out from the food and accumulates at the bottom through the groove evaporates. Since the condensed water is repeatedly passed through the groove and flows down to the bottom, the heating efficiency is improved and the entire contents can be heated uniformly.
Therefore, according to the present invention, when various foods are cooked in a microwave oven, the heating efficiency is improved, the heating time can be shortened and the energy can be saved, and the entire contents can be heated uniformly. A container for heating a microwave oven can be provided.
Further, by setting the protruding height of the convex portion to 4 mm to 30 mm and the minor axis of the horizontal section of the convex portion at a height of 4 mm to a range of 5 mm to 80 mm, food containing a large amount of liquid components is accommodated in the inner container. When cooking, the upper part of a convex part is warmed, this flows toward a side wall part, and it sneaks down further, and it becomes easy to produce the convection of a liquid. When the protrusion height of the convex portion is lower than the above range, the heating efficiency improvement and the effect of uniform heating become insufficient. Moreover, when the protrusion height of a convex part is higher than the said range, a container internal volume will fall and it will become obstructive when eating.
Further, by providing a plurality of the grooves extending from the upper part of the side wall of the inner container toward the convex part, the reinforcing effect of the convex part by these grooves can be obtained, and the convex part can be projected as the microwave heating time elapses. Lowering of the portion is suppressed, and the effect of improving the heating efficiency by forming the convex portion can be maintained.
In addition, by forming a spiral groove on the bottom surface of the inner container, when food containing relatively little moisture is contained and cooked in a microwave oven, it oozes out from the food and accumulates on the bottom through the groove. As the water evaporates and passes through the food and rises while heating, the condensed water is repeatedly flown down to the bottom through the groove, improving the heating efficiency and heating the entire contents uniformly. Can do.
In addition, by providing a horizontal portion at the top of the convex portion, the convex portion does not interfere with contents storage or feeding.
The packaged food for microwave heating according to the present invention is a packaged food packaged in the microwave heating container according to the present invention described above, so that the heating efficiency is improved and the heating time is shortened when cooking in the microwave oven. And energy saving can be achieved, and the entire contents can be heated uniformly.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1-3 is a figure which shows 1st Embodiment of the container for microwave oven heating of this invention, FIG. 1 is sectional drawing of the container 1 for microwave oven heating, FIG. 2 is the principal part of the container 1 for microwave oven heating. FIG. 3 is an enlarged sectional view, and FIG. In these drawings, reference numeral 1 is a microwave heating container, 2 is an outer container, 3 is an inner container, 4 is a flange part, 5 is a flange part, 6 is a mouth part, 7 is a locking part, 8 is a hanging part, Reference numeral 9 denotes a fitting portion, 10 denotes an arc-shaped concave portion, 11 denotes a lid, 12 denotes a fitting convex portion, 13 denotes a lid knob piece, 14 denotes a handle, 15 denotes a convex portion, and 16 denotes a groove.

  A container 1 for heating a microwave oven according to this embodiment includes an outer container 2 made of a thermoplastic resin foam molded body and an inner container 3 made of a thermoplastic resin sheet molded body and placed in the outer container 2. The bottom of the vessel 3 is provided with a convex portion 15 that gradually bulges upward from the periphery of the bottom toward the center, and a groove 16 is provided in the inner container 3. The outer container 2 has a flange portion 4 formed by bending the opening portion outward. The inner container 3 has a flange portion 5 formed by bending an opening portion outward, a tip end side of the flange portion 5 is raised upward, and the cross section is an inverted U shape or an inverted V shape. And a hanging part having a locking part 7 that hangs the tip side of the mouth part 6 downward from the flange part 5 and partly bulges inward in the opening part. 8. In this microwave heating container 1, the inner container 3 is placed in the outer container 2, and the contents of the inner container 3 are placed, and the lower surface of the flange portion 5 of the inner container 3 is placed on the upper surface of the flange 4 of the outer container 2. It is configured to abut.

In the present invention, the overall shape of the microwave heating container is not particularly limited, but the shape of a bowl or pan can be suitably used as a shape suitable for foods such as pots, noodles, porridge, soup, boiled food, and soup. The shape of the container opening is preferably a circle or an ellipse, but a rectangle or a polygon can also be used. Speaking of the relationship between the opening and the depth of the container, it is preferable that the inner container 3 has a short axis a of about 75 to 180 mm and a ratio b / a of a to the depth b of 0.2 to 1. . When the ratio b / a is less than 0.2, the ratio is too shallow, which is not preferable as the food container. When the ratio b / a exceeds 1, it becomes a cup shape and is not suitable for the food.
In this embodiment, the container opening part is circular and the container 1 for microwave oven heating which makes a bowl shape is illustrated. Moreover, in this embodiment, the container 11 for microwave oven heating of the double container structure which combined the outer container 2 and the inner container 3 and the lid | cover 11 fitted inside the mouth part 6 of the inner container 3 so that attachment or detachment is possible. It is the composition which combined.

  In the present embodiment, the outer container 2 is formed by vacuuming a foamed resin sheet having a thickness of 0.3 mm or more obtained by foaming a resin such as polyethylene resin, polystyrene resin, or polypropylene resin at a foaming ratio of 1.5 times or more. What was shape | molded in the shape of the container by shaping | molding, pressure forming, or vacuum / pressure forming etc. can be used preferably. Further, the foaming ratio can be increased by additional foaming during or after the molding. When the thickness of the foamed resin sheet is less than 0.3 mm, the strength necessary for maintaining the shape as a container is insufficient, and the heat insulation and heat retention are insufficient.

  As for the collar part 4 formed in the opening part of this outer container 2, it is preferable that the upper surface is a substantially horizontal surface and the length from a collar part base end to a protrusion is 3 mm or more. If the upper surface of the flange portion 4 is a substantially horizontal plane and the length is 3 mm or more, the flange portion 5 of the inner container 3 is stably placed on the upper surface of the flange portion 4 to stably support the inner container 3. Can do. On the other hand, if the length is too large, it becomes difficult to handle and the appearance is poor, so the length is preferably about 3 to 10 mm. The protruding end of the flange portion 4 abuts between the mouth portion 6 of the inner container 3 and the hanging portion 8 so that the inner container 3 is difficult to come out of the outer container 2.

  The outer container 2 is made of a foam having a low surface hardness so that the surface of the outer container 2 is less likely to be scratched, the outer surface of the outer container 2 is given a design or color to increase its commercial value, or the contents / manufacturer, etc. For example, a transparent, colored or printed thermoplastic film may be affixed to the outer surface and / or the inner surface of the outer container 2 for the purpose of displaying the above. Although the material of a thermoplastic film is not specifically limited, It is desirable to select according to the material of an outer container. For example, when the outer container 2 is expanded polystyrene, a polystyrene-based resin is preferable from the viewpoints of printability, adhesion to a substrate, and the like. The method for sticking the thermoplastic film is not limited, but a method generally used in packaging containers, such as sticking to a sheet before container molding with heat or an adhesive, and then molding to a container can be applied. .

  In the present embodiment, the inner container 3 is a polyolefin resin such as a high density polyethylene resin or a polypropylene resin, a resin in which polyphenylene ether is mixed with polystyrene, or a composition in which a filler such as talc is blended with these resins. A sheet having a thickness of 0.2 to 1 mm made of a material formed into a container shape by vacuum forming, pressure forming, or vacuum / pressure forming can be preferably used. Also, a material made of a crystalline polyester resin such as polyethylene terephthalate, which is made of a non-crystalline sheet into a container by the same method as described above and crystallized by heat treatment to impart heat resistance can be used. If the sheet thickness is less than 0.2 mm, the strength necessary for maintaining the shape of the container is insufficient, and the drooping of the container after heating the microwave oven becomes too large. On the other hand, if the sheet thickness exceeds 1 mm, the container becomes too hard, making it difficult to fit the outer container and the lid, and the weight and cost are excessive.

  The flange portion 5 of the inner container 3 is also a portion that supports the inner container 3 by abutting against the flange portion 4 of the outer container 2 when food is accommodated and also supports the lid 11 in the vertical direction. The width of the flange portion 5 is not particularly limited, but is preferably about 1 mm to 8 mm. The flange portion 5 may be formed in a substantially horizontal plane, but by inclining the mouth portion 6 side at an angle of about 5 to 30 degrees ascending, liquid does not accumulate in the flange portion 5 when eating or drinking heated food. Therefore, it is preferable.

The mouth portion 6 of the inner container 3 is a portion in which the inner container 3 protrudes upward so that a mouth can be easily attached when eating and drinking food in the inner container 3. As for the dimensions of the inverted U-shaped or inverted V-shaped cross section, a width (thickness) of 1 to 10 mm, preferably 2 to 7 mm, and a height of 5 to 30 mm is suitable.
When drinking a liquid with a mouth attached to the mouth portion 6, if the width is less than 1 mm, it feels like it is chewing on paper, and if the width exceeds 10 mm, it becomes too thick and uncomfortable, and the edge of the mouth Easily leaks liquid. Moreover, it is difficult to mold an inverted U-shaped mouth portion having a width of 1 mm or less and a height of 5 mm or more. The top of the inverted U-shaped or inverted V-shaped section is preferably not acute in cross section, and is preferably a semicircular, elliptical or R-shaped polygon.

In the upper part of the inner surface of the mouth portion 6, a tapered fitting portion 9 that is inclined toward the inside of the container is formed in order to guide the lid 11. By forming this fitting portion 9, the lid 11 can be smoothly guided to the mouth portion 6 of the inner container 3, and the lid 11 can be fitted inside and firmly fixed. Prevents spills.
Further, the lower portion of the inner surface of the mouth portion 6 may be a tapered portion inclined toward the outer side of the container so that the lid 11 can be fitted inside.

  An arcuate recess 10 is continuously formed on the inner surface of the mouth 6 along the circumferential direction. The width and the recess depth of the arcuate recess 10 are not particularly limited. For example, the width can be about 5 mm to 30 mm, and the recess depth can be about 0.3 mm to 2 mm. By forming the arc-shaped recess 10, the liquid is less likely to leak from the end of the mouth when drinking the liquid directly from the mouth 6 of the inner container 3.

  The hanging portion 8 provided continuously to the mouth portion 6 has a structure in which the hook portion 4 of the outer container 2 is covered, and a locking portion 7 that bulges toward the inside of the container is provided at the lower portion. In this example, the locking portion 7 is provided in a plurality of island shapes along the circumferential direction of the hanging portion 8. The locking portion 7 is located below the flange 4 of the outer container 2 and is locked to the protruding end of the flange 4 of the outer container 2.

  A pair of grips 14 for holding the container by hand are formed on the hanging portion 8 toward the outside of the inner container 3. At the portion of the handle 14 or at any other position in the circumferential direction, a modification is made such that the flange portion 4 of the outer container 2 is depressed downward or the flange portion 5 of the inner container 3 is depressed upward. It is preferable to provide an air communication portion between the inner and outer containers heated and expanded by microwave heating.

The convex part 15 provided in the bottom part of the inner container 3 should just bulge upwards toward the center from the bottom part periphery of the inner container 3, The shape is not specifically limited, The shape of the inner container 3 Depending on the shape, it may be spherical, cylindrical, conical, frustoconical, quadrangular, quadrangular pyramid, quadrangular pyramidal or the like. In the present embodiment, a truncated cone-shaped convex portion 15 having a horizontal surface at the top is formed.
In this embodiment, the protrusion height y of the convex portion 15 is in the range of 4 mm to 30 mm, and the short diameter of the horizontal section of the convex portion at the height of 4 mm (in this example, the diameter x of the horizontal plane) is in the range of 5 mm to 80 mm. It is preferable. By setting the dimension of the convex part 15 in the above range, when the food container with a large amount of liquid component is accommodated in the inner container 3 and cooked in a microwave oven, the upper part of the convex part 15 is warmed and flows toward the side wall part, Further, it sinks underneath and liquid convection is likely to occur.
The protrusion height of the protrusion 15 is preferably in the range of 8 to 30 mm and the minor axis of the protrusion horizontal cross section at a height of 8 mm is 1 to 60 mm. The protrusion height is 10 to 20 mm and the height is 10 mm. It is further preferable that the minor axis of the convex horizontal section is 1 to 50 mm. If the convex portion 15 is too small, the effect is lost. If the convex portion 15 is too large (particularly, the area is too large), it is the same as simply raising the bottom, and no effect is obtained.

The groove 16 provided in the inner container 3 extends from the upper part of the side wall portion of the inner container 3 toward the convex part 15, and a plurality of grooves 16 are arranged in parallel over the entire periphery of the side wall part of the inner container 3. The groove 16 may be up to the base of the convex portion 15, up to the top, or up to any one between the base and the top.
Thus, by providing a large number of grooves 16 over the entire circumference of the side wall of the inner container 3, the effect of reinforcing the protrusions 15 by these grooves 16 is enhanced, and the protrusions 15 become lower as the microwave heating time elapses. It is suppressed that it becomes, and the improvement effect of the heating efficiency by convex part formation can be maintained.
The shape of the groove 16 is not limited. The cross section of the groove 16 is preferably a smooth shape such as a wave shape or an arc shape. A cross-sectional shape that is bent at an acute angle is not preferable because the contents may be pinched, the liquid material may be stagnated and uniform heating may be hindered, chopsticks, etc. may be caught, causing trouble in eating.
The cross-sectional dimensions of the groove 16 are preferably a groove depth of 0.5 mm to 5 mm and a width of 1 mm to 10 mm. If the groove depth is small, the reinforcing effect is insufficient and it is impossible to prevent the height of the convex portion from being lowered during heating. On the other hand, if the groove is too deep, there is a risk of contact with the outer container 2 and deterioration of heat insulation, deformation due to temperature rise of the outer container 2, etc., and the contents may be pinched or the liquid material may stagnate and inhibit uniform heating This is not preferable because chopsticks and the like may get caught and hinder eating. If the groove width is too small, it is necessary to increase the groove depth in order to obtain a reinforcing effect, which causes the same problem as described above. If the groove width is too wide, the container shape becomes unnatural and the reinforcing effect is difficult to obtain.
In the illustration of FIG. 3, the groove 16 is formed in a spiral shape at the bottom surface of the inner container 3. By providing such a groove 16 in the inner container 3, when food with relatively little moisture is contained and cooked in a microwave oven, the moisture that has leached out of the food and accumulated in the bottom through the groove 16 is retained. It evaporates, passes and rises while heating the food, and the condensed water is repeatedly flown down to the bottom through the groove 16, so that the heating efficiency is improved and the entire contents can be heated uniformly. .
The groove 16 is not limited to the spiral shape, and may be a curved shape, a straight shape, or a combination thereof.

  A space is provided between the inner container 3 and the outer container 2 on the side wall and the bottom. This space is preferably provided over the entire side wall and bottom of the inner and outer containers, but may be a part. A structure may be adopted in which protrusions, ribs, and the like are formed on the outer surface of the inner container 3 and / or the inner surface of the outer container 2 to support the inner container 3, and the interval between the inner container 3 and the outer container 2 can be stably maintained. The air between the inner container 3 and the outer container 2 is preferably blocked by the flange portion 5 and does not reach the mouth portion 6.

  The material of the lid 11 is preferably made of a resin sheet having high transparency and easy molding, such as polystyrene resin and amorphous polyester, but has good heat resistance, such as polypropylene resin, high density polyethylene resin, and crystalline polyester resin. There is no particular limitation.

The shape of the lid 11 is not particularly limited. The central top plate portion of the lid 11 can be formed into an arbitrary shape according to a flat surface, a dome shape, or other uses.
A method of attaching the lid 11 to the inner container 3 is not limited, but a method of fitting the inner lid 3 to the inner container 3 is preferable in order to prevent moisture condensed in the lid from leaking outside. In this case, it is preferable to form a concave or inverted U-shaped concave portion that is fitted into the mouth portion 6 of the inner container 3 in the outer peripheral portion of the lid 11. In the illustration of FIG. 1, a fitting convex portion 12 having a U-shaped cross section extending downward is formed on the periphery of the flat central top plate portion, and a pair of fitting convex portions 12 are formed on the outer periphery of the fitting convex portion 12. The lid knob piece 13 is formed. The fitting convex portion 12 is fitted into the mouth portion 6 of the inner container 3, and the fitted lid 11 can be removed from the mouth portion 6 by picking up and pulling the lid knob piece 13. In addition to this, for example, the lid 11 is simply mounted on the flange portion 5 of the inner container 3 or provided with a downward concave ridge portion that guides the condensed water to fall into the container. A method of externally fitting the outer surface of the mouth portion 6 of the inner container 3 or the hanging portion 8 may be used.
Arranging an arbitrary slit such as a V shape or U shape in the center of the lid 11 is preferable because air expanded by microwave heating or generated steam can be released.

The microwave oven heating container 1 of the present embodiment has a configuration in which a convex portion 15 gradually bulging upward from the periphery of the bottom portion toward the center is provided at the bottom portion of the inner container 3 and a groove 16 is provided in the inner container 3. Therefore, when food containing a lot of liquid components is stored in the inner container 3 and cooked in a microwave oven, the upper portion of the convex portion 15 is warmed, flows toward the side wall portion, and further sinks below, so that the liquid convects. Therefore, the heating efficiency is improved and the entire contents can be heated uniformly. In addition, when food containing relatively little moisture such as rice or pasta is stored in the inner container 3 and cooked by heating in a microwave oven, the moisture that oozes out from the food and accumulates at the bottom through the groove 16 evaporates. Since the food is heated while passing through and rises and the condensed moisture is repeatedly flown down to the bottom through the groove 16, the heating efficiency is improved and the entire contents can be heated uniformly.
Therefore, according to the microwave oven heating container 1 of the present embodiment, when various foods are cooked in a microwave oven, the heating efficiency can be improved, the heating time can be shortened and the energy can be saved, and the entire contents can be achieved. Can be heated uniformly.

  In the microwave heating container 1, the inner container 3 is placed in the outer container 2, the flange portion 4 of the outer container 2 is inserted inside the hanging portion 8, and the upper surface of the flange portion 4 is brought into contact with or close to the flange portion 5. At the same time, the protruding end of the collar portion 4 is brought into contact with the mouth portion 6 and the hanging portion 8 and various foods are accommodated in the inner container 3, and then the lid 11 is fitted inside, or the food products are previously loaded. The inner container 3 accommodated and fitted with the lid 11 is set in the outer container 2 and wrapped in a film or the like as necessary, and used as a microwave-wrapped food.

The food stored in the microwave heating container 1 is a cooked food that is easy to transport and store and can be eaten simply by cooking or thawing with a microwave oven. Liquid ingredients such as sauces, soups and soups used in this food can be solidified with food solidifying agents such as gelatin, agar, carrageenan, guar gum, xanthan gum or mixtures thereof. Among the food solidifying agents, foods obtained by solidifying liquid components with gelatin can be suitably used. The liquid component solidified with a food solidifying agent such as gelatin is liquefied during cooking in a microwave oven and can be mixed with main foods such as noodles.
In addition, main ingredients such as rice, pasta, and noodles can be coated with gelatin jelly and the like so that moisture does not evaporate when cooked or thawed in a microwave oven to become papasa.

  The packaged food for microwave heating according to the present invention is a packaged food packaged in the microwave heating container 1 according to the present invention described above, so that when cooking with microwave oven, the heating efficiency is improved and the heating time is reduced. Shortening and energy saving can be achieved, and the entire contents can be heated uniformly.

[Example]
<Container>
The overall shape of the container was a bowl shape with a circular opening.
The outer container was made of expanded polystyrene having a thickness of 3 mm.
The inner container was made of polypropylene having a thickness of 0.4 mm.
The diameter of the mouth part is 160 mm, the depth (from the mouth part to the deepest part) is 50 mm, the bottom part is provided with a circular convex part with a height of 10 mm and the top part is flat, the width is 7 mm at the top part of the wall part, and the width at the bottom part. A spiral groove that reaches the top of the convex portion while narrowing is provided. This groove bulges out in an arc shape toward the outer side of the container, forms a groove on the inner surface of the inner container, and is provided at 1 mm intervals at the uppermost part over the entire circumference of the wall. (See Figure 3)

<Microwave heating test>
300 g of 28 ° C. water was put in the container, put in a microwave oven (manufactured by Sanyo Corporation, output 800 W), and the time until the water boiled was measured. Water boiling was observed visually.
In the container of this example, it took 2 minutes and 30 seconds on average (3 tests) for water to boil.

[Comparative Example 1]
<Container>
The container was the same as that of the example except that there was no groove in the inner container.

<Microwave heating test>
The test method was the same as in the examples.
In the container of Comparative Example 1, it took 2 minutes and 50 seconds on average (3 tests) for water to boil.
In the container of Comparative Example 1, since there is no rib effect due to the groove, the convex portion becomes lower as the heating time elapses, and as a result that a portion where microwaves are difficult to reach is generated in the inner container, the time until boiling is long. It is thought that it became.

[Comparative Example 2]
<Container>
The container was the same as the container of the example except that the inner container had no grooves and protrusions.

<Microwave heating test>
In the container of Comparative Example 2, it took 3 minutes 00 seconds on average (3 tests) for water to boil.
The water in the bottom center where microwaves are difficult to reach is heated by convection, but in the container of this Comparative Example 2, the bottom center water is difficult to warm because there is no convex part on the bottom, and the time until boiling as a whole It became even longer.

It is sectional drawing which shows one Embodiment of the container for microwave oven heating of this invention. It is a principal part expanded sectional view of the container for microwave oven heating of FIG. It is a perspective view which shows the inner container of the container for microwave oven heating of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container for microwave oven heating, 2 ... Outer container, 3 ... Inner container, 4 ... Gutter part, 5 ... Flange part, 6 ... Mouth part, 7 ... Locking part, 8 ... Hanging part, 9 ... Fitting part, DESCRIPTION OF SYMBOLS 10 ... Arc-shaped recessed part, 11 ... Cover, 12 ... Fitting convex part, 13 ... Cover knob piece, 14 ... Handle, 15 ... Convex part, 16 ... Groove.

Claims (5)

An outer container made of a thermoplastic resin foam molded article and an inner container made of a thermoplastic resin sheet molded article and put in the outer container, and gradually from the bottom periphery to the center of the inner container A microwave oven characterized in that a convex portion provided with a horizontal portion is provided at the top portion that bulges upward, and a plurality of grooves extending from the upper portion of the side wall portion toward the convex portion are provided in the inner container. Container for heating.   The container for heating a microwave oven according to claim 1, wherein the protrusion has a protrusion height of 4 mm to 30 mm and a short diameter of the protrusion horizontal section at a height of 4 mm is in the range of 5 mm to 80 mm. The container for heating a microwave oven according to claim 1 or 2 , wherein the groove has a spiral shape at the bottom surface of the inner container. A packaged food for heating a microwave oven, wherein the food is stored in the inner container of the microwave heating container according to any one of claims 1 to 3 , and a lid is fitted to the inner container and packaged. The packaged food for heating a microwave oven according to claim 4 , wherein the food is prepared such that a liquid component is solidified with a food solidifying agent and the liquid component can be melted when heated.

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