JPH0219407Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a packaging container that prevents the contents from oxidizing by using an oxygen scavenger in a foamed resin container having oxygen-shielding properties.

Foamed resin containers have excellent insulation and cushioning properties and are used for a variety of purposes.

In particular, they are frequently used for food packaging, such as containers for instant foods such as instant noodles, ice cream, coffee, soup, and miso soup. These containers are usually formed by vacuum forming, pressure forming, or other methods using foamed resin sheets or sheets laminated with films for the purpose of protecting the surface, improving printability, and imparting strength, or by forming preliminary materials. It is manufactured by a bead molding method in which foamed particles are filled into a mold and foaming and molding are performed simultaneously.

However, since foamed resin is gas permeable due to its structure, these containers cannot be expected to have oxygen shielding properties and cannot prevent the contents from oxidizing.

However, the above-mentioned foods, especially instant foods, are easily oxidized due to their nature, and have traditionally had problems in terms of quality preservation.

This invention was made in view of the above, and
An object of the present invention is to provide a packaging container that has oxygen shielding properties and maintains a substantially oxygen-free state even though it is a foamed resin container.

That is, in the present invention, a container formed by molding a laminated sheet consisting of a foamed resin sheet layer and an oxygen-shielding resin layer is filled with an oxygen scavenger placed on an inner lid formed into a drop-lid shape along with the contents. The gist of the present invention is a packaging container characterized by being sealed with a drop-lid type vacuum absorbing lid having a convex center portion and a concave outer solid portion having oxygen shielding properties.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a packaging container 1 according to the present invention has a laminated sheet 5 in which a film 4 having an oxygen-shielding resin layer is laminated on a foamed resin sheet layer 2 through (or without) an adhesive layer 3. It is vacuum-formed or pressure-formed with a film 4 having a shielding resin layer on the inside, and an oxygen absorber 7 is filled inside with the contents 6 placed on the inner lid. The inner lid 10 is a drop-lid shaped inner lid for storing the oxygen absorber 7, and has a concave oxygen absorber storage space in the center thereof as shown in the figure. However, if the oxygen-shielding resin layer itself can be laminated directly onto the foamed resin sheet layer 2 using a thermal laminate or the like, the adhesive layer 3 may be omitted. Furthermore, in the molding of the laminated sheet 5, a sheet formed with the film 4 having the oxygen-shielding resin layer on the outside can also be used as a container according to the present invention, although its oxygen-shielding properties are somewhat inferior. Further, the packaging container 1 is sealed at the flange portion 9 by a dome-shaped vacuum absorbing lid 8 made of a film having oxygen-blocking properties.

The lid 8 is a drop-lid type, and after sealing, the oxygen absorber 7
Due to the reduced pressure in the container 1 due to the absorption of oxygen, the container 1
It is made of a flexible material and has a convex central portion and a concave outer circumferential portion so as not to cause deformation or breakage.

Therefore, the lid 8 is recessed due to the reduced pressure inside the container 1.

Therefore, in the present invention, the foamed resin sheet is
The sheet may be a polystyrene foam resin sheet, a polypropylene foam resin sheet, a polystyrene foam resin sheet, etc., and is not particularly limited, but a styrene foam resin sheet is preferably used. For example, styrene foam resin sheets include polystyrene, high impact styrene, and styrene with a thickness of 0.5 mm to 4 mm.
It is made of any one of styrenic resins such as acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene-butadiene-acrylonitrile copolymer, or a mixture of two or more thereof. A styrene resin film may be laminated on at least one surface of this styrene foam resin sheet. Foaming agents for styrenic resins include substances that vaporize above a certain temperature such as propane, butane, and pentane, inorganic foaming agents such as carbonates, bicarbonates, and oxalates, azo-based, nitroso-based, and sulfonylhydra. An organic blowing agent that generates nitrogen through thermal decomposition, such as a diode-based blowing agent, is generally used.

Next, in the present invention, the oxygen-shielding resin layer means:
Examples include saponified ethylene-vinyl acetate copolymer, vinylidene chloride resin, and acrylonitrile resin. The saponified ethylene-vinyl acetate copolymer referred to herein is one having an ethylene content of 25 to 60 mol% and a saponification degree of 95 mol% or more. In addition, vinylidene chloride resin is a resin mainly composed of vinylidene chloride, which is copolymerized with a comonomer such as vinyl chloride, acrylonitrile, acrylic ester, or acrylic acid. In addition, acrylonitrile resin refers to acrylonitrile,
It is a copolymer with acrylic acid esters such as methyl acrylate, ethyl acrylate, and butyl acrylate.

In the present invention, the film having an oxygen-shielding resin layer may be any film that contains the oxygen-shielding resin as a layer, whether it is a single layer or a multilayer structure with other resins. Further, a film made of polystyrene, polyethylene, etc. may be provided on other surfaces of the film, if necessary.

If these films are on the outside, they may be printed.

Next, in the present invention, the term "adhesive layer" refers to urethane resin, epoxy resin, acrylic resin, etc., although it may differ depending on the resin forming the surface to be laminated with the styrene resin foam sheet of the film having the oxygen-shielding resin layer. adhesives such as vinyl acetate resins, rubber derivatives, polyolefins such as polyethylene, ethylene-vinyl acetate copolymers, ionomers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, modified polyethylene, Thermoplastic rubbers such as polybutadiene, polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, etc., as main ingredients polyvinyl acetate, polyvinyl butyral, acrylic resin,
Hot melts containing polyamide, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, etc. are used.

The laminated sheet 1 used in the present invention is manufactured using each of the above base materials, but dry lamination method,
Sand lamination method, thermal lamination method, etc. can be used, and there are no particular limitations.

The base material used for the lid 8 of the packaging container 1 according to the present invention is a film that is flexible and has oxygen shielding properties. This includes one or more of the following: a metal foil layer such as aluminum foil, a metal vapor deposited layer such as aluminum, a resin layer with oxygen shielding properties such as vinylidene chloride resin, acrylonitrile resin, saponified ethylene-vinyl acetate copolymer, etc. Moreover, the film has a layer on one side that can be closely attached to the flange portion of a packaging container by heat sealing, high frequency sealing, ultrasonic sealing, etc.

The oxygen scavenger used in the present invention is not particularly limited as long as it is a substance capable of absorbing oxygen, such as commonly used ferrous salts and sulfites. These oxygen scavengers are used in a state where they are housed in a bag made of an oxygen permeable film or in a state where they are filled with an oxygen permeable resin, but their form is not particularly limited.

The packaging container according to the present invention can be widely and generally used for packaging contents that are resistant to oxidation, and is suitable for packaging foods, especially fried noodles. Furthermore, the packaging container does not have a separate soup and is a cup that has flavor added to the noodles themselves. Ideal for packaging noodles.

Specific examples and comparative examples according to the present invention are listed below.

Example: Packaging container 1 according to the present invention as shown in FIG.
was obtained as follows. 30μ thick low density polyethylene and 30μ thick saponified ethylene-vinyl acetate copolymer (Kuraray, EVAL E) on one side.
The ethylene-vinyl acetate copolymer surface of the film 4, which has an oxygen-shielding resin layer provided with an ethylene-vinyl acetate copolymer (vinyl acetate content: 20% by weight), and the foamed sheet 2 made of high-impact polystyrene with a thickness of 3 mm are combined. Lamination was performed using thermal lamination to obtain sheet 5. A cup having a diameter of 100 mm and an aperture ratio of 1.0 was formed by plug-assisted vacuum forming with the film 4 side of the sheet as the inner surface.

Further, as the inner lid 10, a film made by laminating 150μ low-density polyethylene and 50μ ionomer is thermoformed with a space for storing an oxygen scavenger and the ionomer layer on the outside.

Also 8μ polycarbonate, 15μ ethylene
A film in which saponified vinyl acetate copolymer and 50 μm low-density polyethylene are sequentially laminated is formed into a concave drop lid with the polycarbonate layer on the outside of the concave shape.

Fill a cup with 65g of flavored fried noodles, store an oxygen absorber 7 (Ageless Z, manufactured by Mitsubishi Gas Chemical) in the recess of the inner lid 10, cover the cup with the ionomer layer as the cup side, and then use low-density polyethylene A lid 8 is placed with the layer facing the cup side, and the flange portion 9 is heat-sealed.

The peroxide value of the noodles at the time of filling was 3.1meq/Kg,
Peroxide value after being left at 38℃ for 5 months is 9.2meq/Kg
It was hot.

Comparative Example A foamed sheet made of high-impact polystyrene with a thickness of 3 mm was molded into a cup similar to that of the example.
As lid material, 15μ biaxially oriented polyester, 9μ aluminum foil, 15μ low density polyethylene,
Ethylene-vinyl acetate copolymer containing 30μ of tackifier is used as a sequential laminate.

65g same as in the example in the above cup
Filled with seasoned fried noodles, and heat-sealed with a lid material with the ethylene-vinyl acetate copolymer layer on the cup side.

A time test was conducted under the same conditions as in the example, and the peroxide value was 147 meq/Kg.

As is clear from the above Examples and Comparative Examples, the effects of the Examples in preventing oxidation on the contents of the packaging container according to the present invention are remarkable.

As is clear from the above, the packaging container according to the present invention is a container formed by molding a laminated sheet consisting of a foamed resin sheet layer and an oxygen-shielding resin layer, and is filled with an oxygen absorber placed on the inner lid along with the contents. Since it is sealed with a vacuum absorbing lid that has oxygen shielding properties, it has heat insulation and buffering properties, and it is possible to protect the contents from oxidation. Therefore, for example, in cup packaging for instant foods, powdered soups were conventionally packaged separately in oxygen-blocking pouches, but the oxygen absorber was separated from the contents through the inner lid and filled into the container. Combined with this, it became possible to fill the powder directly into the cup.
In addition, even if the pressure inside the container decreases due to oxygen absorption by the oxygen scavenger after sealing, the container of the present invention has an inner lid formed in a drop-lid shape that is interposed at the top of the container body to reinforce the container body and absorb the reduced pressure. Since the lid is a drop-lid type with a convex center and a concave outer periphery, the lid is easily deformed by suction inward of the container. As a result, the container main body is not subjected to the above-mentioned burden due to the reduced pressure, and there is an advantage that there is no risk of deformation compressing the contents or spoiling the appearance of the container main body.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of one embodiment of the present invention. 1... Packaging container, 2... Foamed resin sheet layer, 3
... Adhesive layer, 4 ... Oxygen-shielding resin layer, 5 ... Laminated sheet, 6 ... Contents, 7 ... Oxygen absorber, 8 ...
...Decompression absorption lid, 10...Inner lid.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A container made of a laminated sheet consisting of a foamed resin sheet layer and an oxygen-shielding resin layer is dropped together with the contents and placed on an inner lid formed into a lid shape. 1. A packaging container filled with an oxygen agent and sealed with a drop-lid-type vacuum absorbing lid having an oxygen-shielding property and having a convex central portion and a concave outer circumferential portion. (2) The packaging container according to claim 1, wherein the laminated sheet is a foamed resin sheet layer laminated with an oxygen-shielding resin layer via an adhesive layer. (3) The packaging container according to claim 1, wherein the foamed resin sheet layer is a polystyrene foamed resin sheet.