JP2002080069A - Cover and container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container wherein when the container closed with a cover is put into a microwave oven, the body of the container is prevented from being ruptured so that the contents thereof can be prevented from scattering in the oven. SOLUTION: The cover includes a base material to close an opening of the body of the container, a hole drilled in the base material, and a closing material provided to close the hole. The strength of the closing material is so specified as to allow the closing material to be broken by the internal pressure of the container when it is heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container containing food to be cooked using, for example, a microwave oven.

[0002]

In recent years, foods in the form of being cooked in a microwave oven as a container have become widespread because they require no labor.

However, if the container is placed in a microwave oven and heated without opening the lid, that is, with the lid kept open, the internal pressure of the container is increased due to the heat treatment, and the container body is broken (ruptured).
The contents may be scattered in the microwave oven.

[0004] For this reason, a slit is formed in a metal member as a part of the exterior material of the sealed container, and the slit is covered with a thermoplastic resin laminated on one surface of the metal member in a non-peelable manner. A sealed microwave cooking container has been proposed in which the thermoplastic resin coated on the slit is melted by microwaves from a microwave oven (Japanese Patent No. 2773138).

[0005] Also, a microwave heating-compatible packaging material comprising a laminated plastic film in which an outer layer is made of a heat-resistant thermoplastic resin film, an inner layer is made of a sealant film, and an intermediate layer is provided with a release agent layer is proposed. (JP-A-9-272180).

However, with the former technique, there is a fear that the thermoplastic resin melted by microwaves in a microwave oven may be melted and dropped into the container and mixed with food.

In the case of the latter, the lid peels off due to an increase in internal pressure during the heat treatment, and water vapor escapes from the peeled portion to prevent the container main body from rupture. This causes problems such as depression.

Accordingly, a first problem to be solved by the present invention is that, when a container is placed in a microwave oven and heated with the lid closed, the container body does not burst and the contents are scattered in the microwave oven. An object of the present invention is to provide a container that does not have any problem.

A second problem to be solved by the present invention is as follows.
Provide a container that not only prevents the container body from bursting when the container is heated in a microwave oven with the lid closed, but also prevents the container body from being dented by decompression after cooling. It is to be.

[0010] A third problem to be solved by the present invention is as follows.
If the container is heated in a microwave oven with the lid closed, not only is the rupture of the container body prevented, but at that time,
An object of the present invention is to provide a container in which a thermoplastic resin melted by microwaves in a microwave oven is melted and dropped into a container, and does not cause anxiety that the thermoplastic resin may be mixed with food.

The object of the present invention is to provide a base material for a lid for closing an opening of a container body, a hole formed in the base material, and a structure provided to close the hole. This is solved by the lid, characterized in that the lid has a strength that breaks due to an increase in internal pressure when the closed container is heated.

That is, a hole of a desired size is formed in a base material of a lid for closing an opening of a container body, and a closing material is provided so as to close the hole. If the strength is set so that the internal pressure increases during processing, the material is damaged (the plugging material is damaged before the container body bursts).
Before the container body ruptures, the blocking material having low mechanical strength is broken, and heated steam or the like scatters outside through the hole.

Therefore, the rupture of the container body is prevented. And the contents do not scatter in the microwave oven.
Also, after cooling, the container body will not be depressed by the reduced pressure. That is, since air freely flows in and out of the hole, the container body does not dent. Furthermore, since it does not melt the plugging material, it does not melt down into the container and does not cause anxiety that it may be mixed with food.

[0013] The object of the present invention is to provide a base material for a lid for closing an opening of a container body, a hole formed in the base material, and a closing member provided to close the hole. The closing material is configured by using a sealant for attaching a lid to the container body, and has a strength that is broken by an increase in internal pressure when a closed container is heated. The problem is solved by a lid characterized in that:

In this case, not only the above-mentioned features are exhibited, but also an agent for attaching the container body to the lid is required for the lid. The lower the cost,
Also, the manufacturing becomes simpler.

In the present invention, in addition to the above constitutional requirements, it is preferable that a sealing material is provided on the surface of the base material on which the plugging material is not provided so as to close the hole. . In particular, it is preferable that the sealing material is configured to be peeled off before the closing material is broken due to an increase in internal pressure when the closed container is subjected to the heat treatment. Above all, it is preferable that the sealing material is configured such that a part thereof is peeled off and a part thereof is not peeled off before the closing member is broken due to an increase in the internal pressure when the closed container is subjected to the heat treatment.

That is, if the sealing material is provided on the upper surface side of the base material, the safety for the contents is increased accordingly.
For example, safety against mischief is increased.

The sealing material having the above-mentioned features is formed using, for example, a heat-shrinkable film. In particular, it is configured using a heat-shrinkable film and a heat transfer material for efficiently transmitting heat to the heat-shrinkable film. Examples of the heat transfer material for efficiently transmitting heat to the heat shrinkable film include a metal powder-containing coating layer. That is, a preferable sealing material can be obtained by applying and drying a paint containing metal powder such as Al powder or Cu powder and a binder resin on one surface of the heat-shrinkable film.

[0018] Further, the above-mentioned object is to provide a base material for a lid for closing an opening of a container body, a hole formed in the base material, and an upper surface side of the base material so as to close the hole. And a sealing material provided, wherein the sealing material has a strength capable of peeling off due to an increase in internal pressure when a closed container is heated.

[0019] The above object is attained by a container characterized by comprising a container main body and the above-mentioned lid provided so as to close an opening of the container main body.

In particular, the apparatus comprises a container body, the above-mentioned lid provided so as to close an opening of the container body, and a cover detachably provided so as to cover the lid. The problem is solved by a container characterized in that a hole is formed in the cover body.

With this cover body, even if the closing material is broken and the contents scatter at that time, the cover body can completely prevent the contents from scattering to the outside.

When the container is placed on a table, it is more preferable to form the cover so that the hole in the cover is not located directly above the hole in the lid base.

BEST MODE FOR CARRYING OUT THE INVENTION A lid according to the present invention is provided such that a base material of a lid for closing an opening of a container body, a hole formed in the base material, and the hole are closed. An obstruction material, wherein the obstruction material has strength enough to be broken by an increase in internal pressure when a closed container is heated. In particular, it comprises a base material for a lid for closing the opening of the container body, a hole formed in the base material, and a closing material provided to close the hole, Is made of a sealant for attaching a lid to a container body, and has a strength that is broken by an increase in internal pressure when a closed container is heated. The portion where the sealant is provided is provided on the entire surface on one surface side (inner surface side) of the lid base material, but is provided on a portion (at least a portion corresponding to the bonding surface with the container body and the hole). It may be. As the sealant, any resin may be used as long as it does not impair the function as a sealant, for example, the functions of sealability, openability, safety, hygiene, etc. when cooked in a microwave oven. For example, polyethylene,
Thermoplastic resins such as polypropylene, polyester and ethylene-vinyl acetate copolymer can be used. The thickness of the sealant layer provided is about 5 to 50, in particular 10 to 25
μm.

A sealing material is provided on the surface of the substrate on which the closing material is not provided so as to close the hole. This sealing material is configured to be peeled off before the closing material is broken due to an increase in internal pressure when the closed container is subjected to heat treatment. Above all, it is configured so that a part is peeled off and a part is not peeled off before the closing material is broken due to an increase in internal pressure when the closed container is heated. Such a sealing material is formed using, for example, a heat-shrinkable film. For example, the shrinkage is 30 to 200%, especially 5
It is configured using a heat-shrinkable film of 0 to 100% (at 80 to 100 ° C). Specifically, a uniaxially stretched polyolefin resin, a polyester resin, or the like can be used. In particular, the heat shrinkable film as described above and a heat transfer material for efficiently transmitting heat to the heat shrinkable film are used. Examples of the heat transfer material for efficiently transmitting heat to the heat shrinkable film include a metal powder-containing coating layer. For example, a preferable sealing material can be obtained by applying and drying a coating containing a metal powder such as Al powder or Cu powder and a binder resin on one surface of the heat-shrinkable film.

The lid according to the present invention comprises a base material for closing the opening of the container body, a hole formed in the base material, and an upper surface of the base material so as to close the hole. And a sealing material provided on the side of the container, the sealing material having a strength capable of peeling off due to an increase in internal pressure when a closed container is subjected to heat treatment.

The container according to the present invention comprises a container body and the above-mentioned lid provided so as to close an opening of the container body. In particular, it comprises a container body, the lid provided so as to close the opening of the container body, and a cover body detachably provided to cover the lid, wherein the cover body Is a hole formed. The holes in the cover are formed such that when the container is placed on a table, the holes in the cover are not located directly above the holes in the lid base material.

The details will be described below.

FIG. 1 is a schematic sectional view of a container provided with a lid according to the present invention, FIG. 2 is a plan view of the lid, and FIG. 3 is a sectional view showing the state of the lid after heat treatment.

In each figure, A is a container body, B is a lid, and C is a cover.

The container body A is formed in a cup shape using, for example, a laminated material of paper and polypropylene.

The cover B includes a base material 1, a sealant layer 2 provided over the entire inner surface (lower surface) of the base material 1,
And a sealing material 3.

The substrate 1 is made of a polyester resin (for example, polyethylene terephthalate) having a thickness of 12 μm and 50 g
/ M @ 2, a 12 .mu.m thick polyester resin having a barrier property against air permeation, a 25 .mu.m thick polyester resin, and a 20 .mu.m thick polypropylene laminated material. Of course, as the substrate 1,
It is not limited to this. Usually, any material that can be used as a lid material can be used.

A hole 4 having a size of, for example, 5 to 30 mm, particularly 7 to 15 mm is formed in the base 1 at a central position. Also, a projection 5 for use as a tab is formed. The sealant layer 2 provided over the entire surface of the substrate 1 so as to close the holes 4 is made of, for example, polypropylene. Incidentally, the thickness of the sealant layer 2 is about 10 to 25 μm.

Reference numeral 3 denotes a sealing material provided on the outer surface (upper surface) of the substrate 1 so as to close the hole 4. The sealing material 3 includes a metal powder-containing coating layer 6 made of Al powder and a binder resin, a heat-shrinkable film 7 such as PET, paper 8,
It comprises a heat-shrinkable film 9 such as ET, a gas barrier film 10, and a sealant layer 11. The configuration of the sealing material 3 is not limited to this. However, those having at least a metal powder-containing coating layer, a heat-shrinkable film, and a sealant layer are preferable.

After the contents D have been put into the container body A, the lid B is placed on the container body A,
The sealant layer 2 is brought into contact with the flange surface of the container body A, and the sealant layer 2 is joined to the flange surface of the container body A by a sealer.
Is fixed to

The cover C, which is detachably provided on the container body A so as to cover the lid B, is formed in a predetermined shape using a transparent or translucent resin material.
The cover body C has a hole 12 formed therein. FIG.
As can be seen from FIG. 7, the position of the hole 12 is formed such that the hole 12 of the cover C is not located directly above the hole 4 of the lid B base material 1 when the container is placed on the table.

When the container constructed as described above is placed in a microwave oven and heated, first, the sealing material 3 is curled as shown in FIG. 3, and the portion corresponding to the hole 4 is peeled off. In addition, since the part which does not correspond to the hole 4 has high sealing strength, it does not peel off as can be seen from FIG.

Thereafter, the pressure in the container increases with heating. Thereby, as can be seen from FIG. 3, the sealant layer 2 at the position facing the hole 4 is broken. And since this connects inside and outside, it does not happen that the container body bursts. Further, the contents D do not scatter outside.

FIG. 4 is a schematic sectional view of a container provided with a lid according to another embodiment of the present invention.

In the above embodiment, the closing member for closing the hole 4 formed in the base material is formed by using a sealant for attaching a lid to the container body.

However, in the present embodiment, as can be seen from FIG. 4, the sealant layer 2 is missing at the position of the hole 4.

The hole 4 is closed by a sealing material provided on the outer surface (upper surface) side of the base material 1. The sealing material 3 peels off due to an increase in internal pressure when a closed container is heated. It is set to be of the strength to be performed.

The sealing material 3 may be of any type as long as it is strong enough to peel off due to an increase in internal pressure when the closed container is heated. For example, the present invention is not limited to the sealing material 3 having the structure of the above embodiment, but the sealing material 3 having the structure of the above embodiment is employed in the present embodiment. Since the components having the same reference numerals as those in FIG. 1 indicate the same configuration, other detailed description is omitted.

According to the present invention, even when the container is placed in a microwave oven and heated with the lid kept on, the container body does not burst and the contents do not scatter in the microwave oven. Further, after cooling, the container body does not dent due to the reduced pressure. Further, the thermoplastic resin melted by the microwave of the microwave oven is melted and dropped into the container, and there is no fear that the thermoplastic resin is mixed with the food.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a container provided with a lid according to the present invention.

FIG. 2 is a plan view of a lid according to the present invention.

FIG. 3 is a cross-sectional view showing a state of a lid according to the present invention after a heat treatment.

FIG. 4 is a schematic sectional view of a container provided with a lid according to another embodiment of the present invention.

[Explanation of symbols]

 A container body B lid C cover body D contents 1 base material 2 sealant layer 3 sealing material 4 hole 5 convex part 6 metal powder containing coating layer 7 heat shrinkable film

Claims (12)

[Claims] 1. A base material for a lid for closing an opening of a container body, a hole formed in the base material, and a closing material provided to close the hole, The lid is characterized in that the closing member has a strength that breaks due to an increase in internal pressure when a closed container is heated. 2. The lid according to claim 1, wherein the closing member is formed using a sealant for attaching the lid to the container body. 3. The lid according to claim 1, wherein a sealing material is provided on a surface of the base material on which the closing material is not provided so as to close the hole. 4. The sealing material according to claim 3, wherein the sealing material is peeled before the closing material is broken by an increase in internal pressure when the closed container is heated.
The lid as described. 5. The sealing material is configured so that a part thereof is peeled off and a part thereof is not peeled off before the closing member is broken due to an increase in internal pressure when the closed container is heated. The lid according to claim 3 or 4, wherein: 6. The lid according to claim 3, wherein the sealing material is formed using a heat-shrinkable film. 7. A sealing material comprising: a heat-shrinkable film; and a heat-transfer material for efficiently transmitting heat to the heat-shrinkable film.
The lid according to claim 6. 8. The lid according to claim 7, wherein the heat transfer material for efficiently transmitting heat to the heat-shrinkable film is a metal powder-containing coating layer. 9. A base material for a lid for closing an opening of a container body, a hole formed in the base material, and a sealing material provided on an upper surface side of the base material so as to close the hole. The lid is characterized in that the sealing material has a strength to be peeled off due to an increase in internal pressure when a closed container is subjected to heat treatment. 10. A container comprising: a container main body; and a lid according to claim 1, which is provided so as to close an opening of the container main body. 11. A container body, a lid provided to close an opening of the container body, and a cover detachably provided to cover the lid. And a body, wherein a hole is formed in the cover body. 12. The container according to claim 11, wherein when the container is placed on a table, the hole of the cover body is formed so as not to be located directly above the hole of the lid base material.