JP2002179144A - Metal containers for food - Google Patents

Abstract

(57) Abstract: A metal container body (2) made of aluminum or the like having a heat resistant resin layer (2e) formed in the innermost layer, and an upper end opening (2a) of the container main body (2) being thermally welded to an opening end (2b). And an opening end 2b of the container body 2 and the container lid 3 are interposed between the sealant layer 4 and the heat-resistant resin via the sealant layer 4 formed on the container lid 3. A food metal container 1 which is heat-welded so as to be peeled off at the interface with the layer 2e. [Effect] A metal container for food that can cook food by moderate rapid heating in the container main body, and then heats the whole container main body when eating sealed food, so that the food can be eaten deliciously. The metal container for food of the present invention is particularly useful as an aluminum container for cooked rice.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case in which food such as cooked rice cooked in a container main body is sealed and stored, and when the food is eaten, the lid of the container is removed to handle metal materials such as a microwave oven. In particular, by aluminum-adaptive heating equipment,
For food metal containers that can be subjected to heat treatment of the stored food together with the container body, more specifically,
The present invention relates to a metal container for food that prevents a sealant layer from remaining on a container body side when a container lid is peeled off, thereby preventing burning due to heat treatment.

[0002]

2. Description of the Related Art In recent years,
After cooking foods such as cooked rice in a plastic container, products sealed in the container are sold as they are, and they are widely used because of their simplicity.However, regarding the taste of the stored food, There was still room for improvement.

That is, for example, in the case of cooked rice, in order to cook delicious rice, it is desirable to continue the rapid heating as early as possible in the early stage of the rice cooking. On the contrary, it has been known that extreme rapid heating cannot be deliciously cooked. I have. However, in the conventional plastic container, in view of the thermal conductivity of the material itself,
It was difficult to set such appropriate rapid heating conditions.

[0004] In order to use a material having an appropriate thermal conductivity among materials that can be used as food containers, it is conceivable to use a metal material such as aluminum. In addition, a metal container is sometimes employed in order to give the processed food a sense of quality. However, metals such as aluminum cannot be heated in a microwave as a whole, like plastic containers, and if heated in a whole container, heat treatment should be performed using a heating tool such as a microwave oven that supports metal such as aluminum. There is a need to do. Usually, the body of such a container is coated with corrosion-resistant coating on the outer surface of aluminum foil and coated with lacquer for heat sealing on the inner surface or plastic rubber (mainly CPP)
Is used. The lid material is made of a material obtained by laminating a heat-resistant lacquer and a coat or a plastic film on a corrosion-resistant aluminum foil. Then, the same type of sealants, that is, heat seal lacquers or plastic films are thermally welded to each other, and the container body is sealed with the container lid.
Therefore, when the lid of such a container is peeled off and opened, the sealant layer is cohesively broken and opened, or even if the sealant layer is peeled off at the interface between the sealant layer of the container body and the sealant layer of the container lid material, the sealant remains on the container body. It will be opened with the layer left. However, in the case of heating with a heating device such as a microwave oven, if the sealant layer remains in the container body when the container lid is peeled off, there is a problem that the sealant layer is burned by the heating.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and not only is it possible to cook food such as cooked rice having a suitable thermal conductivity in a container body in a sealed state, but also to cook the food. An object of the present invention is to provide a metal container for food that can be heated by a microwave oven or the like at the time of eating after sealing and accommodating the prepared food, and can easily provide fragrant food.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a metal container body having a heat-resistant resin layer formed on the innermost layer and an opening end covering the upper end opening of the container body. A heat-welded metal container lid, wherein the open end of the container body and the container lid are provided with a sealant layer formed on the container lid through the sealant layer and the heat-resistant resin layer. A metal container for food, which is heat-welded so as to be peeled off at an interface with the metal container.

[0007] Here, the metal container is a food-grade aluminum container in which food such as cooked rice is sealed and stored,
It is preferable that the apparatus be provided with an aluminum container body and an aluminum container lid. Further, it is more preferable that the sealant layer is formed of an olefin-based resin, or that the innermost layer of the container body is formed of an epoxy-based heat-resistant coating agent. Is particularly effective.

That is, the metal container for food of the present invention is an edible can or a container using a metal material such as aluminum.
Since the container body is made of metal, moderate rapid heating can be continued when cooking foods such as cooked rice and the like, so that the food to be sealed and stored can be deliciously cooked. Since the food filled in the container main body is sealed and stored using the container lid on which the sealant layer is formed, the airtightness of the sealed container is excellent. Here, when the metal container is an aluminum container having an aluminum container main body and an aluminum container lid, it is more effective because it is lightweight and has a suitable thermal conductivity.

In this container, the opening end of the container body and the container lid are heated so as to be separated at the interface between the sealant layer and the heat-resistant resin layer via the sealant layer formed on the container lid. When the food in the container is eaten, the sealant layer is peeled off at the surface of the opening end of the container body when the food in the container is eaten, so that the sealant layer remains on the container lid side. However, since it does not remain on the open end side of the container body, even when the container body is heated by an aluminum-compatible heating device such as a microwave oven, only the open end portion of the container body becomes easily burnt. For example, compared to heating with a heating device for a plastic container such as a microwave oven, it is possible to obtain a more crisp texture and add a fragrant brown color.

Therefore, according to the metal container for food of the present invention, not only can food such as cooked rice be cooked deliciously in the container body, but also the food can be hermetically sealed and stored. Further, when the food in the container is eaten, the whole container body can be heated deliciously.

When the sealant layer is formed of an olefin resin, the surface of the aluminum film forming the container body is heat-resistant on the inner surface of the container, for example, in order to peel off the interface at the surface of the opening end of the container body. When forming the coating layer, it becomes easy to select the type of coating agent, and further, when the innermost layer of the container body is formed of an epoxy-based heat-resistant coating agent, the opening end surface of the container body, that is, Since the interface with the sealant layer becomes an epoxy-based heat-resistant coating layer having a weak peeling force with the sealant layer such as an olefin-based resin,
When the container lid is peeled off, the sealant layer can be surely peeled off at the surface of the coating layer of the container body.

In view of the above characteristics of the metal container for food of the present invention, particularly the aluminum container for food, if the food to be contained is cooked rice such as white rice, fried rice, pilaf, doria, paella, etc. Good and good texture can be obtained by heating at the time of eating.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a longitudinal sectional view schematically showing a container 1 showing one configuration example of a metal container for food (aluminum container for food) of the present invention.

The container 1 includes an aluminum container main body 2 having an open upper end, and an aluminum container lid 3 that covers the upper end opening 2a of the container main body 2 and is heat-sealed to the open end 2b. The opening end 2b of the container body 2 and the container lid 3 are heat-welded via a sealant layer 4 formed so as to be peeled off at the peripheral edge 3a of the container lid. In this container 1, rice (food) 5 is hermetically contained.

Here, the aluminum container main body 2 is mainly made of an aluminum film 2c, a corrosion-resistant coating 2d is applied to a surface of the aluminum film 2c that is to be on the outside of the container, and is further on the inside of the container, and has an opening end 2b. A heat-resistant coating layer (heat-resistant resin layer) 2e is formed on the surface to be the surface, and is formed so as to have a wrinkle-free flange (opening end).

Although the thickness of the aluminum film 2c is not particularly limited, it is usually preferably 20 to 300 μm, particularly preferably 50 to 200 μm. If it is too thin, sufficient strength and airtightness may not be obtained, cracks or pinholes may occur, and if it is too thick, inconvenience such as poor moldability may occur.

The material and thickness of the corrosion-resistant coat 2d are not particularly limited as long as the corrosion resistance of the aluminum film 2c can be prevented, and various synthetic resins can be used. In consideration of the suitability for use, for example, a thermoplastic or thermosetting acrylic-based corrosion-resistant coating agent is preferable, and among these, a thermosetting acrylic-based corrosion-resistant coating agent having high heat resistance is more preferable.

The thickness of the corrosion-resistant coat 2d is 2-30.
μm, especially 5 to 20 μm, is preferred. If it is too thin, sufficient corrosion resistance may not be obtained, and if it is too thick, further corrosion resistance may not be obtained, which may be uneconomical.

The heat-resistant coating layer 2e needs to have heat resistance such that the resin does not melt when heated in a microwave oven or the like, and forms an interface at which the sealant layer 4 formed on the container lid 3 is peeled off. The material and thickness are not particularly limited as long as they can be performed.
For example, epoxy-based heat-resistant coating agents such as epoxy polyamine, epoxy polyamide, epoxy ester, epoxy melamine, and epoxy phenol, and thermosetting acrylic resin coating agents are preferable, and among them, epoxy-based heat-resistant coating agents are more preferable. .

The thickness of the heat-resistant coating layer 2e is 2-3
0 μm, especially 5 to 20 μm, is suitable. If it is too thin, pinholes or cracks may occur in the heat-resistant coating layer during molding of the container body, and if it is too thick, no more heat resistance can be obtained, which may be uneconomical.

The shape and size of the container body 2 are such that they have an upper end opening 2a and can accommodate the food 5 in a sealed manner.
Although not particularly limited, for example, cookware for rice having a capacity such that about 1-2 servings of cooked rice can be filled while leaving an upper space, and usually serving the cooked rice such as a round plate type or a bowl type. It is preferable that the shape is the same as that described above.

The container main body 2 can be manufactured by a known method, for example, using a molding die, and by drawing or bulging. At the time of molding, the container body used in the present invention needs to have a high degree of sealing with the container lid so that the interface can be peeled off. From this viewpoint, it is preferable that the flange has no wrinkles.

The container lid 3 which covers and seals the upper end opening 2a of the container body 2 is mainly made of an aluminum film 3b, and the same corrosion-resistant coating 3c as that of the container body 2 is applied to a surface of the aluminum film 3b on the outside of the container. The sealant layer 4 is formed on the peripheral portion 3a of the inner surface of the container.

The thickness of the aluminum film 3b forming the container lid 3 is not particularly limited, but is usually 3 mm.
The thickness is preferably from 100 to 100 µm, particularly preferably from 50 to 80 µm. If it is too thin, sufficient strength and airtightness may not be obtained, and if it is too thick, rigidity may increase and it may be difficult to open.

The material and thickness of the sealant layer 4 are not particularly limited as long as the interface is peeled off on the surface of the heat-resistant coating layer 2e at the opening end 2b of the container body 2. Due to its high properties, heat can easily escape, and it is difficult for heat to concentrate on the sealant layer. Therefore, a material which can be thermally welded at a low temperature is preferable. Further, from the viewpoint of interface delamination, a material having a larger cohesive force of the sealant layer than a thermal welding force is preferable. Examples of such a material include olefin resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer (EVA), and ethylene-propylene copolymer, and those obtained by introducing a carboxyl group into these olefin resins, ionomers, and the like. Are preferred, and among them, EVA, LDPE, L-LD
PE, ethylene propylene rubber and the like are more preferred.

The thickness of the sealant layer 4 is 5 to 100 μm.
m, particularly preferably 20 to 80 μm. If the thickness is too small, sufficient welding strength or physical strength may not be obtained, and if the thickness is too large, the characteristics are not further improved, so that it is uneconomical.

The corrosion-resistant coat 3c of the container lid 3 is the same as that of the container body 2, but it is not necessary to consider the suitability for a microwave oven, so that general-purpose resins such as polyester and nylon can be used. is there.

The shape of the container lid 3 is particularly limited as long as it covers the upper end opening 2a of the container main body 2 and can be sealed by heat welding with the opening end 2b of the container main body 2 via the sealant layer 4. Not something.

The method for forming the sealant layer on the container lid is as follows.
It can be applied by a known method such as dry lamination extrusion lamination or film sand lamination.

In this container 1, a food material such as rice or water is put in a container body 2, cooked in the container body 2 by a heating method suitable for the food material, and then the container lid 3 2, the upper end opening 2a is covered, and the opening end 2b of the container main body 2 and the peripheral edge 3a of the container lid 3 are heat-sealed via a sealant layer 4 according to a conventional method and sealed. Here, since the container main body 2 has an appropriate heat conductivity, rapid heating according to the food to be cooked is possible, and food such as cooked rice for which appropriate rapid heating is preferable can be deliciously cooked.

Then, when eating the food 5 in the container 1,
When the container lid 3 is peeled off, the sealant layer 4 does not remain on the container main body 2 side, and the innermost layer of the container main body has heat resistance enough not to be melted by heat. If the entire container body 2 is heated using a heating device, the resin does not stick to the flange or adhere to the food 5 and has a crisp texture. ).

It should be noted that the present invention is not limited to the above configuration, and may be variously modified without departing from the gist of the present invention. For example, instead of the aluminum container main body and the aluminum container lid, Iron container body,
A container lid or the like that does not use a metal material can also be used.
The food contained in the container of the present invention is not limited to cooked rice, but may be any of Western-style dishes such as gratin and stew, Japanese-style dishes such as various boiled dishes, and Chinese-style dishes.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

EXAMPLES AND COMPARATIVE EXAMPLES A surface of an aluminum film having a thickness of 140 μm on the outside of the container was coated with a thermosetting acrylic resin (acrylic corrosion-resistant coat) having a thickness of 5 to 6 μm for each layer. The surface to be layer thickness 5-6μ
An aluminum container main body (capacity: 500 ml, round plate type) coated with two layers of epoxy melamine resin (epoxy-based heat-resistant coating layer) was used as the container main body of the example.

On the other hand, as a comparative example, a 25 μm CPP having the same shape and the same capacity as the container body of the above-mentioned embodiment was used as the outermost layer, and EVOH 50 μm, CPP 25 μm, PP
A plastic container body in which 700 μm layers were sequentially laminated was used.

In each of the container bodies of the above Examples and Comparative Examples, rice and an appropriate amount of water for cooking the rice were put in a total of 300.
g, rice cooking time 17 minutes, steam pressure 0.6k
The rice was cooked according to a standard method with g / cm ² and the steaming time was 20 minutes, and the temperature curve of each container body during this period was determined. The results are shown in FIG.

According to the graph of FIG. 2, it is recognized that the rate of temperature rise is much faster in the container body of the embodiment. The cumulative heating time (converted to 121.1 ° C.) of the container body of the example is Fo = 0.4 minutes, whereas the cumulative heating time (converted to 121.1 ° C.) of the container body of the comparative example is , Fo =
0.1 min. When the cooked rice was eaten, the rice using the container body of the example was better in both flavor and taste.

Next, the container body of the above embodiment containing the cooked rice was coated with a 70 μm-thick aluminum film on the outer side of the container by an acrylic urethane resin (acrylic corrosion-resistant coating) having a layer thickness of 5 to 6 μm. ), And the L-LDP is coated on the inner surface of the container so that the layer thickness is 50 μm.
E (olefin-based resin) is dry-laminated (urethane-based adhesive), covered with an aluminum container lid on which a sealant layer is formed, heat-sealed with a sealant layer according to a conventional method, sealed, allowed to cool to room temperature, and then cooled. When the lid was peeled off, the sealant layer did not remain at the opening end of the container body, and it was confirmed that the sealant layer was peeled off at the interface. And
Microwave oven (set temperature 240 ° C, heating time 15 minutes)
When the rice was warmed together with the container body, no scorching was observed at the open end of the container body.

Next, the container body of the above-described embodiment has a thickness of 70
The outer surface of the aluminum film having a thickness of 5 μm is coated with an acrylic urethane resin (acrylic corrosion-resistant coating) having a layer thickness of 5 to 6 μm.
Then, the resin shown in Table 1 is dry-laminated (urethane-based adhesive) to a thickness shown in Table 1, covered with an aluminum container lid having a sealant layer formed thereon, heat-sealed with a sealant layer according to a conventional method, sealed, and room temperature. After cooling, the container lid was peeled off, and the presence or absence of the sealant layer at the opening end of the container body was visually observed and evaluated according to the following evaluation criteria.
The results are also shown in Table 1.

<Sealing conditions> Pressure 4 kg / cm ² Temperature 220 ° C. Time 2.2 seconds Number of times 2

<Evaluation Criteria for Peeling Traces> ：: Peeling without leaving sealant at all △: Sealant remaining extremely thin over the entire opening end ×: Sealant remaining thick over the entire opening end

[0042]

[Table 1]

[0043]

According to the present invention, food can be cooked in the container main body by moderate rapid heating, and thereafter, when the sealed and stored food is eaten, the whole container main body is subjected to a heat treatment so that the food is eaten deliciously. Thus, the food metal container of the present invention is particularly useful as an aluminum container for cooked rice.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a container for explaining one configuration example of the container of the present invention.

FIG. 2 is a graph showing a product temperature curve in a container body of an example of the present invention and a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Container main body 2a Upper end opening part 2b Opening end part 2e Heat resistant coating layer (heat resistant resin layer) 3 Container lid 3a Peripheral part of container lid 4 Sealant layer 5 Rice (food)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuya Fukaya 17 Kagome Co., Ltd. 17 Kagome Co., Ltd. (72) Inventor Akitaka Muraoka Tochigi prefecture Nasu-gun Nishinasuno-cho Oishi Nishi Toyama 17 Kagome Co., Ltd. 4. Inside Nitto Aliman Co., Ltd. (72) Inventor Kinya Sakuma 1578-4, Okada, Shibata-shi, Niigata Prefecture Inside Nitto Ariman Co., Ltd. ) The inventor Fujimori Kogyo Co., Ltd., 1-4-16, Nihonbashi Bakurocho, Chuo-ku, Tokyo Katsumi I (72) Inventor: 1-4-16, Nihonbashi Bakurocho, Chuo-ku, Tokyo Fujimori Industries Co., Ltd.Akira Sasaki (72) Inventor: Naohiro Nomura 1-4-16, Nihonbashi Bakurocho, Chuo-ku, Tokyo Fujimori Kogyo Co., Ltd. F term (reference) 3E067 AA11 AB01 BB11A BB25A BB26A BC07A CA17 CA24 EA06 EA36 EE35 GD08 3E086 AD23 BA04 BA13 BA15 BA24 BB41 BB51 CA01

Claims (5)

[Claims] 1. A container comprising: a metal container main body having a heat-resistant resin layer formed as an innermost layer; and a container lid covering an upper end opening of the container main body and heat-sealing to an opening end. The opening end of the main body and the container lid are heat-welded so as to be separated at an interface between the sealant layer and the heat-resistant resin layer via a sealant layer formed on the container lid. Metal container for food. 2. The metal for food according to claim 1, wherein the metal container is an aluminum container for food in which food such as cooked rice is hermetically sealed, and has an aluminum container main body and an aluminum container lid. Container. 3. The metal container for food according to claim 1, wherein the sealant layer is formed of an olefin-based resin. 4. The metal container for food according to claim 1, wherein the innermost layer of the container main body is formed of an epoxy-based heat-resistant coating agent. 5. The food according to claim 1, wherein the food is cooked rice.
The metal container for food according to any one of claims 1 to 7.