JP3075775B2 - Lunch box - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lunch box container capable of storing food in a lunch box for a long period of time without deteriorating its freshness, taste and aroma when filled with an inert gas.

[0002]

BACKGROUND OF THE INVENTION There are many opportunities to eat a lunch box when traveling, at a resort, at a workplace, etc., but the lunch box must be kept for a certain period of time, for example, within 6 hours after production due to the risk of food poisoning, especially in summer. Had to be served within. Therefore, from the standpoint of the manufacturer of lunches, this means that lunches must be manufactured within a certain period of time, calculated backward from the eating time, which results in a rise in lunch box manufacturing costs and mass production of lunches. Was hindered.
Further, from the standpoint of the eater who eats the lunch, there is a problem that the freshness, flavor, taste and the like of the lunch after the lapse of the manufacturing time have deteriorated.

In order to solve such a problem, Japanese Patent Publication No. Sho 6
Japanese Patent Application Laid-Open No. 3-59659 discloses a method in which a lunch box is filled with nitrogen gas which is an inert gas, and the food in the lunch box can be stored for a long period of time, for example, about one month without deteriorating its freshness. It has been disclosed.

However, in order to store food in an inert gas atmosphere according to the method disclosed in this publication, it is necessary to efficiently fill the lunch box with an inert gas. In this case, this filling step was extremely complicated. For this reason, when a large number of lunches to be stored for a long period of time are produced in a large amount, it is difficult to efficiently supply an inert gas to each of the lunch containers, and it is difficult to mass-produce a lunch for long-term storage.

Further, the present inventor has found that even in ordinary households,
Attempts have been made to preserve lunches for a long period of time using inert gas, but it has been almost impossible to fill an inert gas into a lunch container in a general household by the method disclosed in the above publication.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is very easy to fill an inert gas into a lunch box container, thereby enabling various foods to have a freshness,
An object of the present invention is to provide a lunch container that can be stored for a long time without deteriorating the taste and aroma.

[0007]

SUMMARY OF THE INVENTION In order to achieve this object, a lunch container according to the present invention is provided with a heat generating layer that absorbs oxygen when supplied with oxygen and generates heat in a lunch container having an internal space sealed. An inert gas adsorbing layer which is arranged so that an inert gas is previously adsorbed and heat is transferred from the heat generating layer, and separates and releases the adsorbed inert gas when receiving heat from the heat generating layer And an inert gas releasing device comprising an oxygen-blocking bag covering the heat generating layer and the inert gas adsorption layer.

According to the present invention thus constructed, after the food is placed on the lunch container, the inert gas releasing tool is taken out of the oxygen-blocking bag and placed in the lunch container to seal the lunch container. Then, oxygen in the lunch container is supplied to the heat generating layer, and the heat generating layer generates heat. When this heat is transferred to the inert gas adsorption layer, the inert gas is separated from the inert gas adsorption layer and released. Therefore, the food in the lunch box can be prevented from spoiling, and can be stored for a long time without deteriorating the freshness, flavor, and aroma of the food. Since the filling operation of the inert gas is extremely simple, a long-term storable lunch can be mass-produced, and a long-term storable lunch can be produced even in a general household.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a lunch container according to an embodiment of the present invention will be described with reference to the drawings. First, an inert gas discharging device provided in the lunch container according to the present embodiment will be described.

FIG. 1 is a perspective view of an inert gas discharging device according to an embodiment of the present invention, and FIG. 2 is a sectional view of the inert gas discharging device shown in FIG. In this embodiment, the nitrogen gas releasing device 1 (inert gas releasing device) includes an unoxidized iron powder layer 10 (heat generating layer) obtained by compacting an unoxidized iron powder with a binder, and the non-iron oxide powder layer. And a nitrogen-adsorbing material layer 11 (inert gas-adsorbing layer) formed so as to surround 10.

The use of unoxidized iron powder oxidizes this iron by oxygen in the air present in a closed lunch box 1 as described later, and reduces the heat of formation (heat of exothermic reaction) generated by this oxidation reaction. This is for releasing nitrogen gas N2 from the nitrogen adsorbing material layer 11 into the lunch box 1 by utilizing the same. Therefore, any material other than iron can be used as long as it generates heat when it reacts with oxygen in the air. However, in this case, it is not possible to use a material that may generate a toxic gas or the like by an oxidation reaction, or that the material itself may adversely affect the human body. Further, it is desirable that the heat generated by the oxidation reaction be as large as possible from the viewpoint of reducing the size of the nitrogen gas releasing tool 1. That is, if the amount of heat generated per unit weight is large, the size of the unoxidized iron powder layer 10 can be reduced accordingly.

The nitrogen gas formed on the outer surface of the nitrogen gas releasing tool 8
In this embodiment, the nitrogen adsorbing material layer 11 adsorbs nitrogen in advance.
Zeolite is used. Zeolites are periodic
Crystalline aluminosilicates of Group IA and IIA elements of the table
A salt, structurally AlO _FourAnd SiO_FourAre tetrahedrons
Infinitely wide skeleton by connecting while sharing oxygen ions
It is a crystalline inorganic polymer. Zeolite contains natural
Chabazite, Mordenite, Eri as zeolite
Oneite, faujasite, clinoptilolite, and
A-type zeolite and X-type zeolite as synthetic zeolites
G, Y-type zeolite, L-type zeolite, Omega-type zeolite
And ZSM-5 are used in this embodiment. This
Unconventional zeolites are used to determine the size, shape or polarity of molecules.
Selectively adsorb or exclude molecules based on their properties
Therefore, in the present embodiment, this property is used to
Elemental molecules are adsorbed on zeolite, and this zeolite is used
Molding so as to surround the non-oxidized iron powder layer 10 described above.
You.

The nitrogen adsorbing material in the present invention is not limited to zeolite, but may be another adsorbing material. In short, the nitrogen-adsorbing material of the present invention may be any material that can selectively adsorb nitrogen molecules and has a moldability enough to surround the iron oxide powder layer 10.

The nitrogen adsorbing material layer 11 according to this embodiment includes
A plurality of through holes 12 penetrating into the non-oxidized iron powder layer 10 are formed. As shown in FIGS. 1 and 2, the through holes 12 may be provided on all six surfaces of the nitrogen adsorbing material layer 11, or may be provided on a specific surface. Further, the number and positions of the through holes 12 are not particularly limited. However, as shown in FIGS. 1 and 2, if the through holes 12 formed on the upper and lower surfaces are formed in a staggered manner,
Oxygen can be uniformly introduced to the non-iron oxide powder layer 10.

FIG. 5 shows a nitrogen gas releasing device 8 according to this embodiment.
Of the oxygen-blocking bag 13 formed of a sheet through which oxygen does not pass in order to prevent the oxidation of the non-oxidized iron powder layer 10 until the container is accommodated in the lunch container 20. Is stored in The gas barrier sheet material constituting the oxygen-blocking bag 13 is, for example, an aluminum-deposited film, PVDC-coated cellophane, PVDC-coated biaxially-stretched PET, PVDC-coated biaxially-stretched PP, EVOH,
Examples include a PVDC film and a PVDC-coated biaxially stretched polyvinyl alcohol film.

In the present embodiment, nitrogen gas is used as a gas for suppressing the oxidative action of food and preventing the decay of food. However, if the rot of food can be prevented,
Other inert gases may be used.

In the present invention, since it is sufficient to act as described above, the nitrogen gas releasing tool 1 does not need to be configured as shown in FIG. 1, but may be configured as shown in FIGS.
That is, as shown in FIG. 3, the nitrogen gas releasing device 1 (inert gas releasing device) includes an unoxidized iron powder layer 10 (heat generating layer) and a nitrogen adsorbing material layer 11 (inert gas adsorbing layer). It may be configured simply by bonding. In this case, the same operation as described above can be achieved. Further, in this case, since the non-oxidized iron powder layer 10 is exposed to the air while being stored in the lunch box 1, it is not necessary to form the through holes 12 in the nitrogen adsorbing material layer 11. Further, as shown in FIG. 4, a heat conductive intermediate layer (for example, between the non-iron oxide powder layer 10 (heat generating layer) and the nitrogen adsorbing material layer 11 (inert gas adsorbing layer)).
An adhesive layer 13 may be provided. Again, in this case,
The heat from the non-iron oxide powder layer 10 can be transferred to the nitrogen adsorbing material layer 11, and nitrogen gas can be released.

Next, as shown in FIGS. 5 and 6, the bento container 20 according to the present embodiment has a staple serving section 21 for serving staple rice, and a sub-serving serving for side dishes, salads and the like. Attached portions 22 and 23 and a discharge device housing portion 24 that stores the nitrogen gas discharge device 1 are provided. The wall that partitions each part is lower than the side wall of the container 20. The configurations of the main overlay 21, the secondary overlays 22, 23, and the discharge tool housing 24 are not limited to the embodiment illustrated in FIG. 5, and may be appropriately selected depending on the specifications of the lunch container to which the present invention is applied. can do. For example, when staple rice and side dishes are served in the same section, the shape of the demarcation wall may be changed.

The lunch container 20 according to the present embodiment has
A flange 26 is provided on the entire circumference. A film 27 covering the front of the lunch box is sealed to the flange 26. This sealing means is not particularly limited as long as it is known. As the film 27, a film having low oxygen permeability and excellent in safety is preferable. Specifically, a polyethylene film, a polypropylene film, a polyester film, a pullulan film, or the like is used. Among these, a pullulan film is most preferable, and this pullulan film is composed of a water-soluble, non-gel-forming viscous polysaccharide, and has characteristics of being edible and having a low oxygen permeability. In addition, since the pullulan film can be tightly adhered to the lunch container 20, it also has an advantage that it has excellent sealing properties. In addition, if the lunch container 20 is sealed with this pull-run film, there is also an advantage that it is not necessary to remove the film when heating and heating the lunch.

The lunch container 20 equipped with the nitrogen gas (inert gas) releasing tool 1 operates as follows.
That is, after the rice is put on the main serving portion 21 in the lunch box 20 and the salad is put on the side serving portions 22 and 23, the nitrogen gas releasing device 1 placed in the oxygen-blocking bag 13 is placed.
Is taken out and placed in the lunch container 20, the front surface of the lunch container is covered with a film 27, and the inside of the lunch container 20 is sealed. Then, as well shown in FIG. 2, oxygen present in the food container passes through the through holes 12 of the nitrogen adsorbing material layer 11, reaches the unoxidized iron powder layer 10, and oxidizes the iron powder. Since this oxidation reaction generates heat, the heat generated in the non-iron oxide powder layer 10 is transferred to the nitrogen adsorbing material layer 11, whereby the nitrogen adsorbing material layer 11
The nitrogen molecules adsorbed on the surface absorb active energy and are separated in a gaseous state. When the nitrogen gas is discharged into the lunch container 20 in this manner, the inside of the lunch container 20 becomes a nitrogen gas atmosphere, and as a result, oxidation of food, respiratory action, and evaporation of moisture are suppressed. Therefore, rot of food can be prevented, and the lunch can be stored for a long period of time without deteriorating the freshness, flavor, and aroma of the food. Therefore, even when a long-term storage lunch is mass-produced, it can be produced very efficiently, and according to the present invention, the lunch can be easily stored for a long time even in a general household.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified.

[0022]

As described above, according to the present invention, after food is put on the lunch container, the inert gas releasing tool is taken out from the oxygen-blocking bag, placed in the lunch container, and the lunch container is sealed. . Then, oxygen in the lunch container is supplied to the heat generating layer, and the heat generating layer generates heat. When this heat is transferred to the inert gas adsorption layer, the inert gas is separated from the inert gas adsorption layer and released. Therefore, the food in the lunch box can be prevented from spoiling, and can be stored for a long time without deteriorating the freshness, flavor, and aroma of the food. Since the filling operation of the inert gas is extremely simple, it is possible to mass-produce a long-term storable lunch, and even in a general household,
You can build a long-term storable lunch.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an inert gas discharging device provided in a lunch container according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the inert gas discharging device shown in FIG.

FIG. 3 is a cross-sectional view of an inert gas discharging device according to a modification of the present invention.

FIG. 4 is a sectional view of an inert gas discharging device according to a second modification of the present invention.

FIG. 5 is a perspective view of a lunch container according to one embodiment of the present invention.

FIG. 6 is a sectional view of the lunch container shown in FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Inert gas release tool (nitrogen gas release tool) 10 Heat generation layer (non-oxidized iron powder layer) 11 Inert gas adsorption layer (nitrogen adsorption material layer) 13 Oxygen barrier bag 20 Lunch container

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65D 81/20 A23L 1/10 A23L 3/00 101 A23L 3/3427

Claims (1)

(57) [Claims] 1. A lunch box in which an internal space is sealed, wherein, when oxygen is supplied, a heat generating layer which absorbs the oxygen to generate heat, an inert gas is previously adsorbed, and the heat generating layer An inert gas adsorbing layer that is arranged so as to conduct heat and separates and releases the adsorbed inert gas when receiving heat from the heat generating layer, and covers the heat generating layer and the inert gas adsorbing layer A lunch container comprising an inert gas releasing device comprising an oxygen-blocking bag.