JP2012081999A - Two-stage container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper container excellent in functions such as barrier properties, water resistance, or retort resistance, and capable of cooking different kinds of contents at the same time.SOLUTION: In the two-stage container, an inner surface resin film laminated on an inner surface of the container made of at least paper is slightly larger than the inner surface of the container, and an outer surface resin film laminated on an outer surface of the container is slightly larger than the outer surface of the container, and the inner surface resin film and the outer surface resin film are bonded together to cover a paper end part of a flange, and the two containers are provided. The other container is provided under one container, and they are formed as the upper container and the lower container, respectively, a lid material seals the upper container, the outer surface resin film of the flange of the upper container and the inner surface resin film of the flange of the lower container are bonded with each other, and the lower container is sealed.

Description

  The present invention relates to a paper container for storing food, and relates to a container excellent in barrier properties, water resistance, and retort sterilization resistance.

  Paper containers used as primary containers for food and toiletries are widely used in shapes such as trays, bowls, and cups. Since most of the paper containers directly store the contents, the contents and the inner surface of the container are in contact with each other. As such a primary container, a paper container in which a thermoplastic sheet is laminated on the inner surface of the container is used (Patent Document 1).

  However, since this paper container has a thermoplastic sheet laminated only on the inner surface of the container, the outer surface of the container does not have water resistance, waterproofing, etc., and the outer surface of the container absorbs water when sterilized by retort. There was a problem that. When the outer surface of the container absorbs water, delamination of the paper occurs, causing deformation due to a decrease in strength of the container, and when there is a printed layer on the outer surface, there are various things such as cosmetics due to peeling of the printed layer and missing required information. A malfunction occurs.

  A paper container that can be retort sterilized, can be distributed at room temperature, and can be cooked in a microwave oven, is highly convenient.

  In particular, there are many types of contents that are sterilized by retort and sold. For example, when different types of contents are stored in a tray container, there is a problem that even when a partition is provided, they are mixed during retort sterilization or distribution. Although it is possible to store bags filled with different contents in the tray container, there is a capacity limit. It is desirable to have a completely new container that allows different contents to be eaten together if possible.

JP-A-9-254280

  An object of this invention is to provide the paper container which is excellent in functions, such as barrier property, water resistance, and retort tolerance, and can cook different contents simultaneously.

The invention according to claim 1 of the present invention is formed by laminating an inner surface resin film and an outer surface resin film on at least an inner surface and an outer surface of a paper container made of paper, respectively, and a container having a flange, One size larger than the inside,
The outer surface resin film is slightly larger than the outer surface of the container,
The inner surface resin film and the outer surface resin film are bonded so as to cover the paper end portion of the flange, and are two-stage containers comprising two of the containers,
In the lower part of one container, the other container is provided, and an upper container and a lower container respectively.
Seal the top container with a lid and seal it,
The two-stage container is characterized in that the outer resin film on the flange of the upper container and the inner resin film on the flange of the lower container are bonded together and the lower container is sealed.

  According to a second aspect of the present invention, the upper container and the lower container are separated between the outer surface resin film of the upper container and paper, and the outer surface resin film of the flange of the upper container and the lower container are separated. 2. The two-stage container according to claim 1, wherein an adhesive portion between the flange of the container and the inner surface resin film is peeled off from an intermediate layer of the outer surface resin film of the upper container.

  In the invention according to claim 3 of the present invention, the outer surface resin film of the upper container is composed of a heat-sealing resin layer, a peelable intermediate layer, and an easy peel sealant layer. The two-stage container according to claim 1 or 2, wherein the container is peeled from the container.

  The invention according to claim 4 of the present invention is characterized in that the lid member, the inner surface resin film, and the outer surface resin film have gas barrier properties. It is a two-stage container.

  The invention according to claim 5 of the present invention is the two-stage container according to any one of claims 1 to 4, wherein the lower container has a deeper bottom than the upper container.

  The two-stage container of the present invention is a paper container in which two types of contents are stored in a two-stage container, can be sterilized by retort, and can be stored at room temperature. When the contents are eaten, they can be cooked and eaten in a microwave oven in the same container state.

  According to the first aspect of the present invention, since the resin films are laminated on both the inner surface and the outer surface of the container, it is possible to impart resistance not only to the inner surface of the container but also to the outer surface. Also, by making the inner surface resin film and outer surface resin film one size larger than the container and adhering so as to cover the flange, the paper end surface of the flange is covered, so the strength of the container decreases due to water absorption from the paper end surface, deformation, etc. Can be prevented. Retort sterilization becomes possible. Furthermore, the printed part printed on the outer surface can be prevented from peeling off.

  For example, in order to be able to cook two kinds of contents at the same time, a lower container is provided at the lower part of the upper container to form a two-stage container of the upper container and the lower container, and the outer surface resin film of the upper container flange and the lower container The lower container can be sealed at the same time as the upper container and the lower container are integrated by adhering to the inner surface resin film of the flange.

  According to Claim 2 of this invention, it isolate | separates between paper and an outer surface resin film by weakening the adhesive strength of the paper of an upper container and an outer surface resin film. Moreover, the part which the outer surface resin film of the flange of an upper container and the inner surface resin film of a lower container adhere | attach can peel | separate an upper container and a lower container by peeling from the intermediate | middle layer of an outer surface resin film.

  According to claim 3 of the present invention, the outer surface resin film of the upper container is composed of a thermal adhesive resin layer, an intermediate layer having a release layer, and a sealant layer having an easy peel property, and between the intermediate layer and the sealant layer at the time of release. Use the one that peels off. The sealant layer adheres to the inner surface resin film of the lower container, and after separation of the upper container and the lower container, it remains as a sealant layer at the flange, and the outer surface resin film of the upper container becomes the lid material of the lower container.

  According to claim 4 of the present invention, a gas barrier film is used for the inner surface resin film and the outer surface resin film of the container. In particular, the contents can be prevented from being oxidized and spoiled. In particular, a film that retains gas barrier properties even if the film stretches somewhat is preferable because of the need to follow the shape of the container. A gas barrier film is also used for the lid used for the upper container. This is to prevent oxidative deterioration of the contents of the upper container.

  According to the fifth aspect of the present invention, the lower container is a container having a deeper bottom than the upper container, so that the amount of contents to be put in the lower container can be increased. What is necessary is just to determine suitably with the content part to accommodate. For example, rice can be stored in the lower container as the contents, and curry, side dishes, etc. can be stored in the upper container.

  Even if the contents in the lower container adhere to the outer surface resin film of the upper container during distribution and storefront display, after the upper container and the lower container are separated, the outer surface resin film of the upper container Since it remains as a cover material, it does not adhere to the bottom surface of the upper container and is hygienic. The contents stored in each of the upper container and the lower container can be eaten. It is possible to eat two types of contents.

  The container of the present invention can be a tray-shaped, cup-shaped or bowl-shaped container, each of which can be a two-stage container.

It is a perspective view which shows an example of the container of this invention. It is sectional drawing which shows an example of the container of this invention. It is explanatory drawing which shows an example of the two-stage container of this invention. It is explanatory drawing which shows an example in the flange part of the two-stage container of this invention. It is explanatory drawing which shows an example of the upper container after isolation | separation of the two-stage container of this invention. It is explanatory drawing which shows an example of the lower container after isolation | separation of the two-stage container of this invention.

  Hereinafter, a tray container will be described in detail with reference to the drawings as an embodiment of the present invention.

  In the container of the present invention, a blank (not shown) is prepared according to the container shape after assembling the paper, and then assembled into the container. 1 and 2 show the tray container after assembly, in which an inner surface resin film is laminated on the inner surface and an outer surface resin film is laminated on the outer surface.

  FIG. 1 is an explanatory view showing an example of the container 1 of the present invention. It is a perspective view which shows an example of a tray container.

  FIG. 2 is a cross-sectional view taken along the line AA ′ of the tray container 1 of FIG.

  In the present invention, the inner surface resin film 3 and the outer surface resin film 4 are bonded so as to cover the end portion of the paper of the flange 13 of the tray container. At this time, the inner surface resin film 3 laminated on the inner surface of the tray container 1 is slightly larger than the inner surface of the tray container, that is, the end of the paper, and the outer surface resin film 4 laminated on the outer surface of the tray container is also the tray container. Is larger than the outer surface of the paper, that is, the edge of the paper. The outer resin film 4 of the upper tray container is preferably larger than the inner resin film 3 by one step. This is because it is easy to take when separating the two-stage container.

  FIG. 3 shows the tray container of the present invention that has been made into a two-stage container 10. In particular, the one used for the lower tray container 12 should have a deep bottom. Although there is no limitation in particular, what is necessary is just to determine suitably with the quantity of the content to accommodate, a form, etc. Further, the lower tray container 12 is sealed by bonding the outer surface resin film 4 of the flange 13 of the upper tray container 11 and the inner surface resin film 3 of the flange 13 of the lower tray container 12, thereby forming a two-stage container 10. Also, the lid member 7 is sealed to the upper tray container 11 to form a sealed container, and the two-stage container 10 in which the two sealed tray containers are integrated can be obtained.

  FIG. 4 is an explanatory view showing an example of the flange of the two-stage container 10 of the present invention. The flange 13 has the following configuration. From the top, the cover material 7, the inner surface resin film 3, the adhesive 6, the paper 2, the outer surface resin film 4 having peelability, the inner surface resin film 3, the adhesive 6, the paper 2, the adhesive 6, and the outer surface resin film 5 are provided. . It peels between the intermediate layer and the sealant layer of the outer surface resin film 4 of the upper tray container 11, and is separated into the upper tray container 11 and the lower tray container 12. In this case, the outer surface resin film 4 having the release layer of the upper tray container 11 can be easily peeled off by being pulled together with the lid member 7 by making it one size larger than the inner surface resin film 3.

  FIG. 5 is an explanatory diagram showing an example of a state after separation of the two-stage container of the present invention. In the separated lower tray container 12, the outer surface resin film 4 of the upper tray container 11 remains as a cover material 8. The sealant layer 17 after the outer surface resin film 4 is peeled remains on the flange 13. Since this sealant layer 17 has an easy peel property with the inner surface resin film 3 of the lower tray container 12, the contents can be eaten by peeling off. Moreover, since the sealant layer of the lid member 7 of the upper tray container 11 also has an easy peel property, it can be peeled off to eat the contents.

  As the paper 2 used in the tray container of the present invention, cardboard, paperboard and coated paper can be used. What is necessary is just to select suitably the paper which has the rigidity which maintains the shape of a container especially.

  When paperboard is used as a material, when a blank made of paperboard is made in advance into a tray shape, it is temporarily attached using an adhesive to a blank sticking piece (not shown) to form a tray shape. After assembly, the inner resin film is molded and laminated, and then the outer resin film is molded, laminated, and bonded. Moreover, you may bond an inner surface resin film and an outer surface resin film, without temporarily holding.

  The inner resin film 3 used for the upper tray container and the lower tray container includes polypropylene (PP) such as homopolypropylene, random polypropylene copolymer, block polypropylene copolymer, ethylene vinyl alcohol (EVOH), ethylene and acrylic. Resins such as acid copolymer resin (EAA), nylon (NY), and polyvinylidene chloride (PVDC) can be used. In addition, it is preferable to use a film laminated on polypropylene (PP) / ethylene vinyl alcohol (EVOH) / polypropylene (PP) in view of oxygen barrier properties, water vapor barrier properties, and the like. The above laminated structure is also preferable in the case where hot water treatment such as retort sterilization is performed. As a method for producing a laminated film, a single film may be bonded or a co-extrusion method may be used. The total thickness of each resin film after being laminated on the tray container is desirably 30 μm or more and 500 μm or less. When the film thickness is greater than 500 μm, the film thickness during lamination may become non-uniform, which is not preferable. If it is less than 30 μm, there is a concern that pinholes are generated.

  The outer surface resin film 4 having peelability of the upper tray container is composed of a thermal adhesive resin layer, an intermediate layer having a release layer, and a sealant layer having easy peel properties, and is peeled between the intermediate layer and the sealant layer. The heat sealing resin layer / intermediate layer 16 is on the upper tray container side, and the sealant layer is on the lower tray side. Polypropylene (PP) such as homopolypropylene, random polypropylene copolymer, block polypropylene copolymer, etc. as the heat sealing resin layer, ethylene vinyl alcohol (EVOH), copolymer resin of ethylene and acrylic acid (EAA) as the intermediate layer Resins such as nylon (NY) and polyvinylidene chloride (PVDC) can be used. The sealant layer having easy peel properties can be obtained by imparting easy peel properties to the heat-sealing resin. In addition, a film laminated on polypropylene (PP) / ethylene vinyl alcohol (EVOH) / polypropylene (PP) or polypropylene (PP) / nylon (NY) / polypropylene (PP) can be used because of its oxygen barrier property and water vapor barrier property. In the case where the hot water treatment such as retort sterilization is performed, the above laminated structure is preferable.

  Further, when separating the two-stage container, it is necessary to peel off the part of the lower tray container that is bonded to the inner surface resin film. Therefore, in order to have a release layer on the outer surface resin film, for example, a laminated film of polypropylene (PP) / nylon (NY) and a polypropylene (PP) film having an easy peel property are weakened at the time of bonding. To be able to peel between them. In addition, the outer resin film is made slightly larger than the inner resin film, and the portion is held with both the lid of the upper tray container. By pulling, the portion with weak adhesive strength is peeled off, and the inner resin film is cut and the upper tray container is cut. Paper and the outer resin film are separated. The PP film having easy peel properties remains on the flange portion of the lower tray container and remains as an easy peel sealant layer.

  Further, the outer surface resin film 4 laminated with the paper of the upper tray container becomes a cover material of the lower tray container after separation. When the lid is peeled from the lower tray container, the sealant layer has an easy peel property, so that the lid can be easily peeled off and the contents can be taken out.

  As the sealant layer 17 having easy peel properties, there are a cohesive failure type and a delamination type.

  The cohesive failure type is a type in which the sealant layer itself cohesively breaks. Using a resin mixed with resin such as polypropylene, polyethylene, polystyrene, etc., it is formed into a film and laminated on the base material layer, or the coating solution of this resin is used. It can be used by coating.

  For example, a resin in which a polyolefin resin such as polyethylene, high-density polyethylene, linear low-density polyethylene, or polyethylene is mixed with a polybutene resin, or a resin in which a polyolefin resin and a polystyrene resin are mixed can be used.

  The delamination type is a method in which a three-layer film is prepared by a coextrusion method and is peeled from an intermediate layer. This coextruded film can be used by being laminated on a base material layer.

  Any of the above two types can be used as the sealant layer having easy peel properties. The thickness and the like may be determined as appropriate from the peel strength, peelability, and the like.

  The outer surface resin film 5 used in the lower tray container includes polypropylene (PP) such as homopolypropylene, random polypropylene copolymer, block polypropylene copolymer, ethylene vinyl alcohol (EVOH), copolymer of ethylene and acrylic acid. Resins such as resin (EAA), nylon (NY), and polyvinylidene chloride (PVDC) can be used. A film laminated on polypropylene (PP) / ethylene vinyl alcohol (EVOH) / polypropylene (PP) is preferable in view of oxygen barrier properties, water vapor barrier properties, and the like. The above laminated structure is also preferable in the case where hot water treatment such as retort sterilization is performed. As a method for producing a laminated film, a single film may be bonded or a co-extrusion method may be used. The total thickness of each resin film after being laminated on the tray container is desirably 30 μm or more and 500 μm or less. When the film thickness is greater than 500 μm, the film thickness during lamination may become non-uniform, which is not preferable. If it is less than 30 μm, there is a concern that pinholes are generated.

  In order to separate the two-stage container, the inner resin film of the upper tray container, the inner resin film and the outer resin film of the lower tray container are bonded to paper through an adhesive to increase the adhesive strength. The upper tray container and the lower tray container can be separated by making the external resin film of the upper tray container and the paper pseudo-adhesive without using an adhesive and weakening the adhesive strength.

  As the adhesive 6, a polyolefin-based adhesive can be used. In advance, an adhesive is applied to the paper with a coater. The coating amount may be determined appropriately while confirming the adhesive strength. In the upper tray container, the inner surface resin film is applied to the surface to be laminated. In the lower tray container, the inner resin film surface and the outer resin film are applied to the surfaces to be laminated. As the coater machine, a known printing method such as gravure printing, offset printing, silk screen printing method, and ink jet printing method, or a known coating method such as roll coating, knife coating, comma coating, and gravure coating can be used. About drying conditions, it can carry out by the hot air drying generally used. About an application quantity, what is necessary is just to determine suitably the adhesive strength of paper, an inner surface resin film, and an outer surface resin film.

  Next, a method of laminating the inner resin film on the inner surface of the paper tray container and the outer resin film on the outer surface will be described.

  The method of laminating the paper tray container and the inner surface resin film can be performed by a vacuum forming method, a pressure forming method, or a forming method using both the vacuum forming method and the pressure forming method. The inner surface resin film may be laminated, and then the outer surface resin film may be laminated, or may be laminated at the same time.

  An inner resin film is placed on a paper tray container placed in the mold. The flange of the tray container and the inner resin film are bonded by a method such as heat sealing, and at the same time, the inner resin film is softened by heating with infrared rays or hot air. The heating temperature and the like are appropriately determined depending on the material and thickness of the inner surface resin film to be used. After that, when air in the mold is sucked through a suction tube and a suction hole from a vacuum source such as a vacuum pump, the air in the mold is sucked through a gap in the folding portion of the paper tray container, and the inside is in a vacuum state. As a result, the heat-softened inner surface resin film is bent by suction pressure and is tightly formed on the inner surface of the tray container, and is integrally formed with the tray container. It is also possible to improve the adhesion by using plug assist. Adhesiveness is enhanced on the surface where the adhesive has been previously applied to the paper. On the surface where no adhesive is applied, the adhesiveness is weak and pseudo-adhesion occurs.

  However, since the adhesive is not applied to the outer paper surface of the upper tray container, the adhesiveness to the heat-formed inner surface resin film is weak. In this part, the upper tray container and the lower tray container can be separated.

  Next, the lid member 7 used for the upper tray container will be described. The lid member is preferably made of a sealant layer having an oxygen barrier property, a water vapor barrier property, and an easy peel property. For example, a film laminated on polypropylene (PP) / ethylene vinyl alcohol (EVOH) / polypropylene (PP) having easy peel properties is preferable. A film in which nylon (NY) is laminated as an intermediate layer can also be used. Moreover, the film which vapor-deposited the inorganic compound layer can also be used. As the inorganic compound layer, aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof can be used. Any layer having transparency and having an oxygen barrier and a water vapor barrier may be used. As a method for depositing the inorganic compound, a vacuum deposition method or other thin film formation methods such as a sputtering method, an ion plating method, a plasma vapor deposition method, or the like can be used.

  Paper can also be used for the intermediate layer. In this case, as the barrier layer, an aluminum foil, a film deposited with aluminum, or a film deposited with other inorganic compound layers can be laminated and used. In this case, it is necessary to cover the edge of the paper with a resin film at the peripheral edge of the paper.

As the sealant layer having easy peel properties, there are a cohesive failure type and a delamination type.

  The cohesive failure type is a type in which the sealant layer itself cohesively breaks. Using a resin mixed with resin such as polypropylene, polyethylene, polystyrene, etc., it is formed into a film and laminated on the base material layer, or the coating solution of this resin is used. It can be used by coating.

  For example, a resin in which a polyolefin resin such as polyethylene, high-density polyethylene, linear low-density polyethylene, or polyethylene is mixed with a polybutene resin, or a resin in which a polyolefin resin and a polystyrene resin are mixed can be used.

  The delamination type is a method in which a three-layer film is prepared by a coextrusion method and is peeled from an intermediate layer. This coextruded film can be used by being laminated on a base material layer.

  Any of the above two types can be used as the sealant layer having easy peel properties. The thickness and the like may be determined as appropriate from the peel strength, peelability, and the like.

  Since the two-stage container of the present invention is a container that can be sterilized by retort after storing the contents, it can be distributed at room temperature.

  Part of the lid of the tray container is peeled off, and the tray container can be cooked and eaten by heating in a microwave oven.

  Desired patterns, characters, and the like can be printed on the outer surface of the paper in the tray container. It is also possible to cover the upper tray container. The printing method can be performed by offset printing, gravure printing, silk screen printing, inkjet printing, or the like.

  As described above, the tray-shaped two-stage container has been described as an embodiment. However, a two-stage container can be created in the same manner even in a cup shape or a bowl shape. In addition to a method of making a blank from paperboard and assembling and forming a container, a pulp mold container that has been previously formed into a tray shape, a cup shape, or a bowl shape can also be used.

  Since the contents put into the two-stage container of the present invention can store different kinds of contents in the upper container and the lower container, they can be used for rice and side dishes, curry, stew, and other cooked side dishes. Industrial materials have a wide range of applications such as two-component adhesives and those that can be used as products by mixing two types.

1: tray container 2: paper 3: inner surface resin film 4: peelable outer surface resin film 5: outer surface resin film 6: adhesive 7: cover material (upper tray container)
8; Lid (lower tray container)
10; Two-stage container 11; Upper tray container 12; Lower tray container 13: Flange 14: Bottom 15: Adhering piece 16: Thermal adhesive layer / intermediate layer 17: Sealant layer

Claims (5)

At least an inner surface resin film and an outer surface resin film are laminated on an inner surface and an outer surface of a paper container made of paper, respectively, and a container having a flange,
The inner resin film is slightly larger than the inner surface of the container,
The outer surface resin film is slightly larger than the outer surface of the container,
The inner surface resin film and the outer surface resin film are bonded so as to cover the paper end portion of the flange, and are two-stage containers comprising two of the containers,
In the lower part of one container, the other container is provided, and an upper container and a lower container respectively.
Seal the top container with a lid and seal it,
A two-stage container, wherein an outer surface resin film of a flange of an upper container and an inner surface resin film of a flange of a lower container are bonded to each other, and the lower container is sealed.   The upper container and the lower container are separated between an outer surface resin film of the upper container and paper, and an adhesive portion between the outer surface resin film of the flange of the upper container and the inner surface resin film of the flange of the lower container The two-stage container according to claim 1, wherein the two-stage container is peeled off from the intermediate layer of the outer surface resin film of the upper container.   The outer surface resin film of the upper container is composed of a heat-sealing resin layer, a peelable intermediate layer and an easy peel sealant layer, and peels from the intermediate layer when peeled. Or the two-stage container of 2.   The two-stage container according to any one of claims 1 to 3, wherein the lid member, the inner surface resin film, and the outer surface resin film have gas barrier properties.   The two-stage container according to any one of claims 1 to 4, wherein the lower container has a deeper bottom than the upper container.

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