WO1998054056A1

WO1998054056A1 - Sealed container

Info

Publication number: WO1998054056A1
Application number: PCT/JP1997/001848
Authority: WO
Inventors: Kazumasa Kimoto; Katuhito Hirai; Kuniaki Inayoshi
Original assignee: Sumitomo Bakelite Company, Ltd.; Fuji Oil Company, Ltd.
Priority date: 1997-05-30
Filing date: 1997-05-30
Publication date: 1998-12-03
Also published as: KR20010013083A; KR100430516B1; EP1048574A1

Abstract

An easily openable, sealed container which contains contents larger than a container body and is made gastight by heat sealing a container lid and the container body. The sealed container comprises a container lid having a flange portion and a convex-shaped portion formed by a double or multi-layered sheet, of which an outermost layer is of polycarbonate and of which an innermost layer is of a resin capable of heat sealing with the container body, and the container body having a flange portion, a periphery of one of the flange portions being provided with a fitting portion adapted to cover the other of the flange portions, the flange portions being heat sealed with each other, and the heat-sealed flange portions of the container lid and the container body being easily openable.

Description

Description Sealed container Technical field

The present invention relates to a sealed container. More specifically, the present invention relates to an easily-openable hermetically sealed container which can be suitably used for packaging foods and the like, which is obtained by heat-sealing a lid container having a convex shape and a main body container. Background art

With the diversification of lifestyles, cooked foods filled in sealed containers have been widely used in ordinary households. Cooked foods that have been sterilized under pressure and heat can be stored at room temperature for about one year without losing their taste, and can be ready for meal by heating the containers in a microwave oven or boiling water. Such foods were mainly offered in bags when they first appeared, but the types of food were curry, meatballs, hamburgers, stewed vegetables, chikuzenni, roll cabbage, steamed tea, and soup. With the diversification of red rice, etc., there has been a growing demand for an easily-openable sealed container that can be placed on a table as it is.

Conventionally, as an easily openable sealed container obtained by heat-sealing the lid container and the main container, the following containers are used. FIG. 1 is an explanatory diagram of a conventional sealed container. The sealed container shown in this figure is formed from a multilayer sheet of two or more layers whose innermost layer is a resin that can be heat-sealed with the innermost layer of the main container. A lid container 3 fitted with the main container, and a main container 5 having a flange portion 4. After filling food 6 into the main container, fit the lid container into the main container. By fitting the lid container into the main container, the lid container is positioned and there is no risk that the lid container will be displaced from the main container.

7 and pressurized by a heat-sealing hot plate 8 under certain conditions, the lid container and the main container can be heat-sealed and sealed at the flange portion. Also, By appropriately selecting the material of the flange portion and the heat sealing conditions, it is possible to provide easy-openability in which the heat-sealed flange portion can be opened by a human hand. However, such a conventional easy-opening sealed container has a structure in which the lid container has a concave portion in order to provide a fit between the lid container and the main container. The volume is limited to less than the capacity of the container. In recent years, it has not been possible to deal with the use of side dishes with volumes as contents. -In addition, when filling food with a larger capacity than the main container, non-sealed containers have been used exclusively in the past. FIG. 2 is an explanatory view of one embodiment of a conventional non-sealed container. The container shown in this figure is composed of a flange portion 1 and a convex portion 9, and has a lid container 3 having a fitting portion 10 which covers the periphery of the flange portion of the main body container on the periphery of the flange portion, and a body having a flange portion 4. Container 5 After filling food 6 into the main container, the fitting part provided on the periphery of the flange portion of the lid container is placed over the flange portion of the main container to fix the lid.Such containers are conventionally heat-sealed. It is mainly used for foods that do not require preservation, such as take-out lunches, sushi, Japanese sweets, etc.The container is made of a single-layer material such as a stretched polystyrene resin sheet or a vinyl chloride resin sheet I have.

An object of the present invention is to provide a sealed container which is filled with contents larger than the main container, heat-sealed the lid container and the main container, has airtightness, and is easy to open. is there.

Disclosure of the invention

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, formed from a multilayer sheet in which the outermost layer is a heat-resistant polycarbonate, and the innermost layer is a resin heat-sealable with the main container. It was found that a heat-sealed lid container having a fitting portion with the main container was heat-sealed with the main container at the flange portion to obtain a hermetically sealed container with easy-opening properties. The invention was completed.

That is, the present invention (1) a lid container having a flange portion and a convex portion molded from a multilayer sheet of two or more layers in which the outermost layer is polycarbonate and the innermost layer is a resin heat-sealable with the main container, A flanged portion of a main container having a flange portion, a fitting portion covering the other flange portion provided on a peripheral edge of one flange portion, and heat-sealed and heat-sealed at the flange portion. Is a sealed container that is easy to open,

(2) The innermost layer of the lid container is made of polypropylene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polystyrene, acid-modified polyethylene, ethylene-methacrylic acid copolymer and The sealed container according to item (1), which is one or a mixture of two or more selected from ethylene-methacrylic acid copolymer metal crosslinked products,

(3) The sealing described in (1) or (2), wherein the intermediate layer of the lid container includes a laminated structure of polypropylene (vinyl acetate monoacetate or polyvinylidene chloride) in order from the outer layer side. Container,

(4) Item (1), item (2) or item (3), wherein the main container is formed from a multilayer sheet laminated in order of polypropylene-no-ethylene-vinyl acetate copolymer gemide Z polypropylene. Sealed container,

(5) Item (1), (2), (3) or (4), wherein the lid container has a raised portion around the upper part of the convex portion to be fitted to the bottom of the main container. ) Described sealed container,

(6) The main body container has, at the bottom, a concave portion which can be deformed into a convex shape by the internal pressure when heated, according to the above items (1), (2), (3), (4) and (5). ) Described sealed container,

Further, as a preferred embodiment of the present invention,

(7) The sealed container according to paragraph (1), (2), (3), (4), (5) or (6), wherein the lid container has an opening tab. ,

Can be mentioned. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view of a conventional sealed container, and FIG. 2 is a diagram of a conventional non-sealed container. FIG. 3 is an explanatory view of an embodiment of the sealed container of the present invention. FIG. 4 is a cross-sectional view showing a state in which the sealed container of the present invention is being opened. Fig. 6 is an explanatory view of the sealed container of the present invention having a raised portion in the lid container. Fig. 6 (a) is a plan view of the sealed container of the present invention having a concave portion at the bottom of the main body container. FIGS. 6 (b) and 6 (c) are cross-sectional views of the sealed container of the present invention having a concave portion at the bottom of the main container, and FIG. 7 (a) is a sectional view of the present invention having an opening tab on the lid container. FIG. 7 (b) is a cross-sectional view of the sealed container of the present invention having an opening tab in the lid container, and FIG. 8 is a sealed view of the present invention filled with boiled vegetables. It is explanatory drawing of a container.

The reference numerals in the figure are: 1 is a flange portion, 2 is a concave portion, 3 is a lid container, 4 is a flange portion, 5 is a main container, 6 is food, 7 is a heat seal cradle, 8 is a heat seal hot plate, 9 is A convex portion, 10 is a fitting portion, 11 is a raised portion, 12 is a concave portion, and 13 is an opening tab. BEST MODE FOR CARRYING OUT THE INVENTION

The lid container of the sealed container of the present invention is formed from a multilayer sheet of two or more layers in which the outermost layer is a polycarbonate and the innermost layer is a resin capable of being heat-sealed with the innermost layer of the main container. Polycarbonate has a glass transition temperature of about 150 ° C and a fluidized state of about 240 ° C, which is excellent in heat resistance. It can withstand 50 to 190 ° C. Polycarbonate has excellent transparency and allows the contents to be filled in from the outside, so it is suitable for use as food containers.

The innermost layer of the multilayer sheet used for molding the lid container can be used without particular limitation as long as it is a resin that can be heat-sealed with the innermost layer of the main container. It is preferable to select a resin having an appropriate peel strength and easy opening. Examples of such resins include polypropylene, low-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, acid-modified polyethylene, polystyrene, ethylene-methacrylic acid copolymer, Examples include crosslinked ethylene-methacrylic acid metal copolymers. Only one of these resins can be the innermost layer, or two or more Resin can be mixed to form the innermost layer. Examples of the mixed resin of the innermost layer of the multilayer sheet used for forming the lid container include, for example, polypropylene and low-density polyethylene, polypropylene and high-density polyethylene, polypropylene and ethylene-vinyl acetate copolymer, and polypropylene and polystyrene. Mixed resins can be mentioned. Between the outermost layer and the innermost layer of the multilayer sheet used for forming the lid container, a saponified ethylene-vinyl acetate copolymer, vinylidene chloride is used to improve gas barrier properties against oxygen, nitrogen, carbon dioxide, etc. Resins and the like, and for the purpose of improving the water vapor barrier property, a chloride vinylidene resin, polypropylene, polychlorinated trifluoroethylene and the like can be appropriately laminated. Examples of the multilayer sheet used for molding such a lid container include a multilayer sheet having a four-layer structure of a mixed resin of a polycarbonate polypropylene non-ethylene monoacetate copolymer saponified polypropylene and a high-density polyethylene. And a multi-layer sheet having a four-layer structure of a mixed resin of polycarbonate, polypropylene, polyvinylidene chloride, Z-polypropylene and high-density polyethylene.

The main container of the sealed container of the present invention can be heat-sealed with the innermost layer of the multilayer sheet used for forming the lid container, and can be formed into a single-layer sheet that can be easily opened. The resin can be heat-sealed with the innermost layer of the multilayer sheet used in the present invention, and can be molded from a multilayer sheet having an innermost layer of a resin that can be easily opened. Examples of such a single-layer sheet include a single-layer sheet of polystyrene, polypropylene, polyvinyl chloride, and the like. Examples of a multilayer sheet include, for example, polypropylene // ethylene-vinyl acetate copolymer genide Z Examples thereof include a multilayer sheet of polypropylene. Also, in order to obtain particularly good easy-openability, the innermost layer should be made of polypropylene and low-density polyethylene, polypropylene and low-density polyethylene and high-density polyethylene, polypropylene and ethylene-methacrylic acid copolymer metal crosslinked product, and polypropylene. It is preferable to use a mixed resin such as an ethylene-methacrylic acid copolymer or a linear low-density polyethylene.

In the case where the sealed container of the present invention is filled with food, and then pressurized and heat-sterilized to produce a retort bouch food, the materials of the lid container and the main container are determined according to the processing conditions in the pressurized heat sterilization pot. Shall be able to withstand. Materials suitable for such retort bouch foods include, for example, a combination of a lid container made of a two-layer sheet of a mixed resin of polycarbonate polypropylene and high-density polyethylene, and a main container made of a single-layer sheet of polypropylene, or a lid container. Polycarbonate polypropylene Polyester saponified ethylene monoacetate copolymer Z-polypropylene and high-density polyethylene mixed resin four-layer sheet, main container made of polypropylene polyethylene mono-vinyl acetate copolymer saponified polypropylene three-layer sheet, etc. Can be mentioned.

The method for producing the multilayer sheet used in the sealed container of the present invention is not particularly limited, and it can be produced by a known lamination method such as dry lamination, coating, extrusion lamination, and coextrusion. An adhesive layer can be interposed between the layers as needed. The method for forming the lid container and the main container of the sealed container of the present invention is not particularly limited, and the container can be formed by a known method such as vacuum forming, pressure forming, and vacuum forming.

FIG. 3 is an explanatory view of one embodiment of the sealed container of the present invention. The hermetically sealed container shown in this figure has a flange portion 1 and a convex portion 9 molded from a multilayer sheet of two or more layers, the innermost layer of which is a resin capable of heat sealing with the innermost layer of the main container. A lid container 3 having a fitting portion 10 that covers the periphery of the flange portion of the main container on the periphery of the main container, and a main container 5 having a flange portion 4. In the sealed container of the present invention, after the food 6 is filled in the main container, the fitting portion of the peripheral edge of the flange portion of the lid container is fitted over the peripheral edge of the flange portion of the main container. The fitting of the flange on the peripheral portion of the lid container and the flange of the main container allows the positioning of the lid container and eliminates the possibility that the lid container is displaced from the main container. In this state, the container is placed on the heat-seal pedestal 7, pressurized under a certain condition by the heat seal hot platen 8, and the flange of the lid container is heated, so that the lid container and the main container are heated by the flange. It can be sealed and sealed. In addition, by appropriately selecting the material of the innermost layer of the lid container and the main container and the heat sealing conditions, the heat-sealed flange can be easily opened by hand without the need for tools. Opening property can be given. FIG. 4 is a sectional view showing a state in which the sealed container of the present invention is being opened. Generally, the temperature of the heat seal hot plate is preferably 150 ° C. to 190 ° C. Therefore, the outermost layer of the lid container is at least 10 ° C. lower than the melting point of the resin of the innermost layer to be heat-sealed. It is preferable to have a melting point higher by at least ° C, preferably at least 20 ° C, but polycarbonate having excellent heat resistance satisfies this condition.

In the sealed container of the present invention, a raised portion that fits with the bottom of the main container can be provided around the upper portion of the convex portion of the lid container. FIG. 5 is an explanatory view of the hermetically sealed container of the present invention having a raised portion in the lid container. In the present embodiment, a raised portion 11 that fits with the bottom of the main container 5 is provided around the upper part of the convex portion 9 of the lid container 3. In the sealed container of this aspect, when stacked, the raised portion of the lid container and the bottom of the main container fit together and do not collapse, so that a large number of sealed containers can be easily handled.

In the sealed container of the present invention, a concave portion that can be deformed into a convex shape by internal pressure during heating can be provided at the bottom of the main container. FIG. 6 (a) is a plan view of the main container of the sealed container of the present invention having a concave portion at the bottom, and FIG. 6 (b) is a diagram of A in a state where the lid container and the flange portion of the main container are heat-sealed. FIG. 6 (c) is a cross-sectional view taken along line A-A in a state where the concave portion is deformed into a convex shape by internal pressure during heating. In the present embodiment, an elliptical concave portion 12 is provided at the bottom of the main container 5 so that the contents are filled, and the lid container and the main container are heat-sealed with the flange portion. As shown in the figure, the recess retains its original shape. When the sealed container filled with the contents is heated for sterilization of the contents, the inside of the sealed container is pressurized, but at this time, the concave part is deformed to a convex shape as shown in Fig. 6 (c). However, since the internal volume of the sealed container is increased, the internal pressure is reduced, and peeling of the heat seal and damage to the sealed container due to the pressure can be prevented.

The sealed container of the present invention can be provided with an opening tab to facilitate opening.FIG. 7 (a) is a plan view of a lid container of the sealed container of the present invention having an opening tab, and FIG. b) is a cross-sectional view taken along the line B-B in a state where the flange portions of the lid container and the main container are heat-sealed. In this embodiment, the opening tab 13 is formed by expanding one corner of the flange portion of the lid container and leaving a portion that is not heat-sealed with the flange portion of the main container. When opening the sealed container, put your finger on this opening tab, By pushing the lid container upward, the sealed container can be easily opened. The position of the opening tab is not limited to the corner of the flange portion, but can be provided at any position.

In the sealed container of the present invention, after opening and removing the lid container, the content food can be put on a table as it is and served for meal without transferring the food as a content to another container. If the material of the multi-layer sheet used can withstand heating by a microwave oven, simply open it, remove the lid container, cover the fitting part of the lid container again with the flange of the main container, It can be served in a microwave after heating.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1

The outermost layer is a polycarbonate with a thickness of 0.25 dragons and the innermost layer is a mixed resin of polypropylene and polystyrene with a thickness of 0.05 mm. A truncated cone-shaped lid container having a diameter of 70 mm and a convex portion having a height of 10 mm was formed by vacuum forming. In addition, a polypropylene container sheet with a thickness of 0.8 ram, a flange of 5 widths, a capacity of 200 ml, a depth of 50 mm and a diameter of 70 mm, a frustoconical frustoconical container, It was formed by vacuum forming.

The main container was filled with 210 g of boiled vegetables containing 50 ml of soup stock, and fitted into the flange portion of the main container while fitting the fitting portion of the periphery of the flange portion of the lid container. The boiled vegetables filled over the edge of the main container and were easily seen from outside through the lid container. Next, as shown in Fig. 8, after the flange of the container was placed on the heat-sealing pedestal, it was heated to 190 ° C, and the cylindrical heat-sealed heat was heated to 190 ° C and the internal diameter was 73 mm. The flange was pressurized by a disk at a pressure of 3.0 kg / cm ² for 2.5 seconds using a sealing machine with a cylinder diameter of 100. The container could be completely sealed by heat sealing without any deformation of the convex part of the lid container.

The sealed container filled with simmered this vegetable, with a shower sterilizer, at 1.3 under a pressure of kg / cm ² at Teisa圧, after sterilizing 9 8 ° C, 3 0 minutes, the cold storage Two weeks saved. At the time of serving the meal, the lid was easily opened by peeling off the fitting part of the lid container with a finger. After fitting the lid container to the main container again and heating it with a microwave oven, it was possible to obtain cooked warm vegetables. I removed the lid container and placed it on the table without transferring it to another container. However, I did not feel any discomfort in the container, and I could eat deliciously without changing the flavor of the boiled vegetables just after cooking.

Example 2

In order from the outermost layer, the thickness is 0.06 polycarbonate, 0.1 mm thick polypropylene Z, 0.015 thick polyvinylidene chloride Z, 0.05 thick polypropylene and high-density polyethylene. A 0.18 mm thick multi-layer sheet made of a mixed resin, with a flange with a width of 7 mm with a fitting portion, with a convex portion of 80 mm long, 100 mm wide and 10 mm high Was molded by vacuum molding. Also, in order from the outermost layer, the thickness of the polypropylene is 0.38 imn, the thickness is 0.04 mm, the thickness of the polypropylene is 0.08 mm, and the thickness of the polypropylene is 0.8 mm. From the co-extruded multilayer sheet, a main body container having a flange portion with a width of 5 and a capacity of 20 Om, a length of 80 mm, a width of 100 mm and a depth of 25 mm was formed by vacuum forming.

After filling the main container with 250 g of Chikuzen-ni, the fitting was carried out in the same manner as in Example 1, while fitting the fitting portion of the flange of the lid container into the flange of the main container. Next, after placing the flange part of the container on the heat seal receiving table, the heat seal heat plate heated to 190 ° C was used for 3 seconds at a pressure of 3.0 kg / cm ^{2 using a} 100 mm diameter cylinder sealing machine. The flange was pressurized. The container could be completely sealed by heat sealing without any deformation of the convex part of the lid container.

The sealed container filled with the Chikuzen boiled, using a retort sterilization kettle under pressure to adjust at Teisa圧2. AkgZcin ^2, and sterilized 1 20 ° C, 3 0 minutes. After storage at room temperature for 2 weeks, the fitting part of the lid container was peeled off with a finger, and the container could be easily opened. The flavor of Chikuzen-ni was unchanged after cooking.

Example 3

A lid container having the same shape as in Example 2 was prepared. The same outermost layer as in Example 1 was a 0.25 mm thick polycarbonate resin, and the innermost layer was 0.05 mm thick polypropylene and polystyrene. It was formed by vacuum pressure molding using a two-layer sheet, which is a resin mixture of the two. Fig. 6 (a) has the same flange, the same length, width, and depth as in Example 2, and has an elliptical shape with a long diameter of 70mm and a short diameter of 50mm at the bottom and a depth of 7mm. A main body container having the shape shown in the figure was molded from a polypropylene sheet having the same thickness as 0.8 in Example 1 by vacuum air pressure molding.

This main container was filled with 250 g of boiled vegetables containing 50 ml of soup stock, and fitted into the flange portion of the main container while fitting the peripheral portion of the flange portion of the lid container. Next, the flange portion of the container was placed on a heat seal receiving table, and the flange portion was pressed at a pressure of 3.0 kg / cm ² for 2.5 seconds by a heat seal hot plate heated to 190 ° C. The container was completely sealed by heat sealing without any deformation of the convex part of the lid container, and a sealed container having the shape shown in Fig. 6 (b) could be obtained.

The sealed container filled with the boiled vegetables was heated at 98 ° C. for 10 minutes under a constant differential pressure of 1.0 kgZcm ² using a shower type sterilizer. The concave portion provided at the bottom of the container is deformed into a convex shape as shown in FIG. 6 (c), and sterilization can be performed while maintaining the sealing property.

The same operation as in Example 3 was repeated, except that no concave portion was provided at the bottom of the main container.

Using a shower-type sterilizer, 1. When heated at 98 ° C for 10 minutes under a constant differential pressure of OkgZcm ^2, a part of the heat seal on the flange part came off, and the sealability was lost. Industrial applicability

INDUSTRIAL APPLICABILITY The sealed container of the present invention has a large internal volume, can be filled with a large amount of contents, can maintain good sealing properties by a heat seal, and can be easily opened by a human hand.

Claims

The scope of the claims

1. A lid container having a flange portion and a convex portion, formed from a multilayer sheet of two or more layers in which the outermost layer is polycarbonate and the innermost layer is a resin heat-sealable to the main container, and a flange portion. A fitting part is provided on the periphery of one flange part to cover the other flange part, and the flange parts of the lid container and the main body container that are heat-sealed at the flange parts and heat-sealed are easily opened. Is a sealed container.

2. The innermost layer of the lid container is made of polypropylene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polystyrene, acid-modified polyethylene, ethylene-methacrylic acid copolymer and ethylene. 2. The sealed container according to claim 1, wherein the container is one or a mixture of two or more selected from methacrylic acid copolymer metal crosslinked products.

3. The sealed container according to claim 1 or claim 2, wherein the intermediate layer of the lid container has a laminated structure of polypropylene Z (ethylene vinyl acetate acetate copolymer or polyvinylidene chloride) in order from the outer layer side.

4. The sealed container according to claim 1, 2 or 3, wherein the main container is formed from a multilayer sheet laminated in the order of saponified polypropylene-no-ethylene-vinyl acetate copolymer.

5. The sealed container according to claim 1, wherein the lid container has a protruding portion around the upper portion of the protruding portion, the protrusion being fitted to the bottom of the main container.

6. The sealed container according to claim 1, claim 2, claim 3, claim 4, or claim 5, wherein the main body container has, at the bottom, a concave portion that can be deformed into a convex shape by internal pressure when heated.