JP2004244034A - Packaging containers and packages - Google Patents

Abstract

Disclosed is a method of filling a container body with a flange at normal temperature with food and sealing the package with a lid body when heating and selling the package body in a hot warmer installed in a convenience store or the like. Provided are a packaging container and a package that prevent peeling of the package.
A packaging container includes a container body having a barrier property and a lid, and the lid includes a laminate including at least a barrier layer, an oxygen absorbing layer, and a sealant layer. Using this packaging container, the container body is filled with food at room temperature, and the mouth of the container body is sealed with a lid to form a package. This package is provided for hot sale by a hot warmer.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to packaging containers and packages for foods such as soups, milks, milk coffees, milk teas, fruit juices, etc., which are distributed and sold at chilled or normal temperature and eaten at a temperature of about 45 ° C. to 70 ° C.
[0002]
[Prior art]
It is packaged in a packaging container such as a cup-shaped container or a plastic molded container, distributed and sold at chilled or normal temperature, and is sold in a hot warmer installed in a convenience store at a temperature of about 45 ° C to 70 ° C at the time of drinking. For example, there are foods such as soups, milk, milk coffee, milk tea, juice drinks, and the like.
[0003]
By the way, since oxygen is present in the head space of a package formed by filling a cup-shaped container with food and sealing with a lid, the internal pressure rises during heating by a hot warmer, so that the lid becomes large. It may swell, and in some cases, the lid may peel off from the container body. Further, the liquid packaging contents may spill from the container due to the impact of the peeling of the lid. Further, if the lid is deformed or peeled off during the heating sale, the commercial value is thereby impaired.
[0004]
Claim 1 of Patent Document 1 states that at least a part of the container is, from the inner surface side to the outer surface, a heat-sealable thermoplastic resin inner layer, an oxygen-absorbing thermoplastic resin layer, and a thermoplastic resin having a thickness of 10 μm or more. A sealed container excellent in storability characterized by comprising a laminated container material of a cushion layer, an oxygen barrier layer, and a heat-resistant resin outer layer. " A container comprising a seam container main body and a lid, wherein the upper surface of the flange of the container main body and the inner surface of the lid are joined by heat sealing, wherein at least the lid is made of the laminated container material. 1). " However, in the detailed description of the invention of Patent Document 1, in paragraph 0025, as a preferred embodiment of the invention, “the shape of the container of the container of the present invention is, for example, as shown in FIG. Cup with a heat-sealable lid made of a flexible substrate obtained by laminating a thermoplastic resin film on both sides of the laminate or metal foil of the present invention. The lid is made of the laminated container material of claim 1, and the flanged container body is made of a thermoplastic resin film or a laminate thereof. Not.
[0005]
However, in paragraph 0019 of Patent Document 1, “In the present invention, the two layers (the oxygen-absorbing agent-containing resin layer and the oxygen barrier layer) are flexible and have good shape-following properties, and also have affinity for the resins of both layers. By providing a cushion resin layer having an adhesive layer, the bonding surface with the oxygen barrier layer is smoothed, transfer of the uneven surface shape is avoided, shock energy such as impact is absorbed and reduced by a cushion effect, and interlayer adhesion strength is provided. It is apparent from the description that the chilled food is filled into a flanged cup-shaped container as described in paragraph 0003 of the specification of the present application, and a lid is provided. It does not refer to the prevention of deformation of the lid during heating by the hot warmer or peeling from the container body, which occurs with respect to the chilled food package sealed with the above.
[0006]
[Patent Document 1]
JP-A-9-40024 (Claims 1 and 3, paragraph "0025" and FIG. 2)
[0007]
[Problems to be solved by the invention]
An object of the present invention is to fill a container body with a flange at normal temperature with a food, and to deform a lid which occurs when a package formed by sealing with a lid is heated and sold in a hot warmer installed in a convenience store or the like. An object of the present invention is to provide a packaging container and a package in which peeling from a container body is prevented.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 solves the above-mentioned problem relating to the packaging container, and includes a container body having a barrier property and a lid, and the lid includes at least a barrier layer, an oxygen absorbing layer, and a sealant layer. The gist of the present invention is a packaging container comprising a laminate.
[0009]
In the present invention, any of a container body with a flange, a container body with a circular annular edge, and a container body without a flange can be applied as the container body. However, it goes without saying that a container body with a flange is desirable from the viewpoint of adhesiveness to the lid member.
[0010]
In the packaging container of the present invention, since the lid is provided with the oxygen absorbing layer, oxygen in the head space is absorbed by the oxygen absorbing layer, and dissolved oxygen in the package contents is absorbed by the oxygen absorbing layer via the head space. You. The pressure in the head space is reduced by the amount of oxygen in the head space absorbed by the oxygen absorbing layer, the lid is deformed into a concave shape, and the head space is reduced.
[0011]
On the other hand, when the lid does not have an oxygen absorbing layer, the air in the head space expands and the internal pressure rises due to the release of water vapor and dissolved oxygen from the contents during heating by the hot warmer, so that the lid is heated. Swells greatly, and in some cases, the lid may swell and peel off from the container body. On the other hand, in the packaging container of the present invention, the head space is reduced in pressure by the amount of oxygen in the head space absorbed by the oxygen absorbing layer, and the head space is reduced. During the warming by the hot warmer, the nitrogen in the head space expands, and the dissolved oxygen remaining from the package contents causes the internal pressure to rise and the head space to increase, but the oxygen in the head space is increased by the oxygen absorption layer. The head space is decompressed by the amount absorbed, and the head space is reduced, so that the lid is restored to a flat state or the lid is slightly expanded so that the center part of the lid swells about 1.5 mm with respect to the peripheral edge of the lid. Stay deformed.
[0012]
In the packaging container according to the present invention, the lid may include a protective layer made of plastic or paper outside the barrier layer. Printing may be performed on the protective layer.
[0013]
In the packaging container of the present invention, the sealant layer of the lid is desirably 60 μm of an ethylene-propylene copolymer polyolefin resin. When the lid is peeled off from the flange of the container body, the sealant layer is peeled off from the flange surface of the container body with feathery stringing without causing cohesive failure of the sealant layer, and the sealant contained in the oxygen absorbing layer is removed. The iron powder of the oxygen agent is not exposed on the flange surface.
[0014]
The sealing temperature when sealing the lid to the flange of the container body, the circular annular edge or the upper end of the side wall of the container body is preferably 230 ° C., more preferably 180 ° C. or less. If the temperature exceeds 180 ° C., cohesive failure of the sealant layer occurs near the oxygen absorbing layer at the time of opening, and iron powder can be seen on the flange surface.
[0015]
In the present invention, the flanged container main body having a barrier property includes: (a) an in-mold label biaxial stretch blow-molded container or an in-mold label injection molded container formed using an in-mold label molding label having a barrier layer; It can be constituted by b) a multilayer injection molded container containing a barrier resin layer, or (c) a molded container formed by molding a multilayer sheet containing a barrier resin layer.
[0016]
The invention according to claim 13 solves the above-mentioned problem relating to the package, wherein the packaging container according to any one of claims 1 to 12 is used, and the food is packaged in the container body. And a head space is present on the package contents, and the mouth of the container body is sealed by a lid.
[0017]
In the package of the present invention, oxygen in the head space is absorbed by the oxygen absorbing layer of the lid, and dissolved oxygen in the package contents is absorbed by the oxygen absorbing layer via the head space. Therefore, during the heating by the hot warmer, the nitrogen in the head space expands and the remaining dissolved oxygen comes out of the package contents, thereby increasing the internal pressure and increasing the head space. The pressure in the head space is reduced by the amount absorbed by the oxygen absorbing layer, and the head space is reduced, so that the lid is restored to a flat state or the center of the lid is about 1.5 mm with respect to the peripheral edge of the lid. It stays slightly deformed to the extent that it swells. Therefore, an accident that the commercial value is impaired due to the deformation of the lid or the detachment from the container body during the heating sale is prevented.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the package of the present invention will be specifically described with reference to the drawings.
[0019]
1A to 1D are schematic diagrams illustrating the configuration and functions of the package of the present invention. As shown in FIG. 1 (A), the package of the present invention comprises a lid 1 and a container body 2 with a flange. Chilled food, such as soup, milk, milk coffee, milk tea, fruit juice, etc., which is heated and eaten, is filled as the package contents 3, and a head space 4 exists on the package contents 3 and is flanged by the lid 1. The mouth of the container body 2 is sealed. The lid 1 is composed of a laminate having an oxygen absorbing layer and a sealant layer, and the flanged container body 2 is composed of a flanged container body having a barrier property.
[0020]
After the package body of the present invention is filled with the package contents 3 and the opening of the flanged container body 2 is sealed with the cover body 1, as shown in FIG. The oxygen in the head space 4 and the dissolved oxygen contained in the package contents 3 are absorbed, and the pressure in the head space 4 is reduced accordingly, and the lid 1 is deformed into an indented shape. Form.
[0021]
When the package body of the present invention is put into a hot warmer and the package contents 3 are heated to 55 to 60 ° C., the internal pressure in the head space 4 increases, and the lid body is in a flat state 1b as shown in FIG. The state is restored, or the state 1c is expanded by about 1.5 at the center compared to the periphery. On the other hand, when the lid does not have the oxygen absorbing layer, the lid may have a large swelling and, in some cases, peel off. The impact of the peeling of the lid may cause the contents of the liquid package to spill. In addition, deformation or peeling of the lid during the warming sale by the hot warmer impairs the commercial value, which is very inconvenient for the store.
[0022]
FIG. 2 shows the configuration of the lid. The lid 1 has a protective layer 5 / barrier layer 6 laminated on an oxygen absorbing layer 8 / polyolefin layer 9 with an adhesive layer 7 interposed therebetween.
[0023]
The protective layer 5 protects the barrier layer 6 and includes an olefin resin such as polyethylene terephthalate, nylon, low-density polyethylene, medium-density polyethylene, high-density polyethylene, and polypropylene; and a polyamide such as nylon-6 and nylon 6,6. It consists of a kind. The protective layer 5 may be printed. This protective layer may be omitted in some cases.
[0024]
Next, the barrier layer 6 is made of a metal foil such as aluminum, steel, tin or the like or polyethylene terephthalate and aluminum, SiO _X And the like.
[0025]
Next, the oxygen absorbing layer 8 is made of a resin mixed with an oxygen absorbing agent. As the oxygen absorbent, any conventionally used oxygen absorbent can be used, but in general, those which are reducible and substantially insoluble in water are preferred. Suitable examples thereof include reducing metal powders, such as reducing iron, reducing zinc, and reducing tin powder: low-metal oxides, such as ferrous oxide and ferric oxide: reducing metal compounds, such as , Iron carbide, iron silicon, iron carbonyl, ferrous hydroxide, and the like, or a combination of two or more thereof. These oxygen absorbers can be combined with auxiliary agents such as alkali metal, alkaline earth metal hydroxide, carbonate, sulfite, thiosulfate, tertiary phosphate, activated alumina, and activated clay as needed. Can be used. In general, these oxygen absorbents preferably have an average particle size of 50 μm or less, particularly preferably 30 μm or less. Further, the oxygen absorbent is preferably blended in an amount of 1 to 100 parts by weight, particularly 10 to 50 parts by weight, per 100 parts by weight of the following resin.
[0026]
As the resin containing the oxygen absorbent, a conventionally known resin that can be formed into a film can be used.In particular, a resin having water absorption itself, so that the oxygen absorbing layer can effectively absorb moisture, For example, a copolymer obtained by saponifying an ethylene vinyl alcohol copolymer having an ethylene content of 20 to 60%, particularly 25 to 50% by mole, so that the degree of saponification becomes 96% by mole, particularly 99% by mole or more. A saponified ethylene vinyl alcohol copolymer can be used. This saponified ethylene vinyl alcohol copolymer has a molecular weight sufficient to form a film, and is generally measured in a mixed solvent having a weight ratio of phenol: water of 85:15 at a temperature of 30 ° C. It is desirable to have a viscosity of at least 0.01 dl / g, especially at least 0.05 dl / g.
[0027]
In addition, resins that do not absorb themselves, such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, isotactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene- Olefinic resins such as butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ion-crosslinked olefin copolymer (ionomer), or a blend thereof, include polyacrylic acid, Polymethacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyvinyl methyl ether, polyvinyl alcohol, vinyl alcohol-acrylic acid copolymer, modified polyethylene oxide, sodium acrylate polymer, acrylic acid, acrylate, grafted starch, starch Krill nitrile grafting hydrolyzate can be formulated grafted cellulose acrylate, a superabsorbent polymer such as starch or grafted derivatives of cellulose, such as acrylate grafted cellulose as water-absorbing agent. In addition to these resins, inorganic salts such as sodium sulfate, magnesium sulfate, disodium phosphate and sodium diphosphate, organic compounds such as modified casein and modified starch, silica gel, alumina gel, diatomaceous earth, and various water absorbing inorganic materials such as zeolite. Compounds can be formulated.
[0028]
The sealant layer 9 can be heat-sealed to the flange of the container body with a conventionally known heat-sealing resin, and firmly adheres to the oxygen absorbing layer to prevent phase separation and cohesive failure between the oxygen absorbing layer / sealant layer. A material that can be peeled off from the flange without raising it can be used. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, isotactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 An olefin-based resin such as a copolymer or an ethylene-propylene-1 copolymer can be used. Particularly, as the sealant layer 9, an ethylene-propylene copolymer olefin resin (EP-W60) is preferable.
[0029]
In addition, since the oxygen absorbing layer is colored by the oxygen absorbing agent, it is preferable to mix and color a conventionally known white pigment such as titanium white so as to cover the oxygen absorbing layer.
[0030]
FIG. 3 shows a lid in which a paper layer 5a is laminated on the barrier layer 6 via a bonding layer 7a instead of a plastic film as a protective layer. Other configurations (the barrier layer 6, the oxygen absorption layer 8, and the polyolefin layer 9) are the same as the configuration of the lid shown in FIG.
[0031]
Next, the container body 2 will be described. The container body 2 having a barrier property includes (a) an in-mold label biaxial stretch blow-molded container or an in-mold label injection molded container formed using an in-mold label molding label having a barrier layer, and (b) a barrier resin. It can be constituted by a multilayer injection-molded container containing a layer or (c) a molded container formed by molding a multilayer sheet containing a barrier resin layer.
[0032]
FIG. 4 shows a flanged in-mold label biaxial stretch blow-molded container formed using an in-mold label molding label having a barrier layer. In this container, a label for in-mold label molding is attached in a blow mold, and the preform inserted in the blow mold is biaxially stretch blow molded to form a biaxially stretched blow molded product having a predetermined shape. In doing so, what is called in-mold label molding is performed in which an in-mold label molding label is simultaneously attached to the surface of the biaxially stretched blow molded product. It has a label 11 for molding a mold label. 2a indicates a flange, and this portion is left undrawn so that heat sealing can be performed.
[0033]
The biaxially stretched blow-molded article 10 is made of polyethylene terephthalate, polypropylene, polycarbonate, or the like. In particular, polyethylene terephthalate is preferably a molded article made of polyethylene terephthalate because it is excellent in preventing water vapor, oxygen, odor, ultraviolet light, etc. It is.
[0034]
5A to 5E are cross-sectional views showing the configuration of the in-mold label forming label 11, and FIG. 5A is a schematic cross-sectional view showing the basic configuration of the in-mold label forming label. It is. The in-mold label forming label 11 is composed of a base material 12 and an adhesive layer 13, and the adhesive layer 13 is made of a heat-adhesive material that softens and melts at 130 ° C. or lower and adheres to the surface of the stretched molded article.
[0035]
Here, (a) low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer polymerized using a metallocene catalyst, polypropylene, ethylene -Vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer Modified polyolefin resins such as poly (meth) pentene polymer, polyethylene or polypropylene, modified with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and other unsaturated carboxylic acids, poly (meth) acrylic resin, heat Plastic polyester type (B) an unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate, etc., having a heat seal layer, and (c) ethylene-vinyl acetate copolymer. A hot melt adhesive layer containing a coalesced layer, or a heat sealant layer containing (d) an ethylene-vinyl acetate copolymer can be used.
[0036]
The substrate 12 includes a barrier layer, an ultraviolet protection layer, a printing substrate layer, and the like, which will be described below.
[0037]
FIG. 5B shows the label 11 in which the base material 12 includes the barrier layer 14 and the printed base material layer 15. In this case, the print pattern layer 16 is provided on the print base material layer 15. Each layer of the barrier layer 14 and the printing base material layer 15 can be formed independently by forming a film and dry laminating with an adhesive, or by co-extruding a part or all of the layers. it can. In addition, the printing base material layer 15 can be omitted according to the use and purpose.
[0038]
The barrier layer 14 is made of an unstretched or stretched plastic film, such as polyethylene, polypropylene, or polyethylene terephthalate, coated with (a) an aluminum foil and (b) a metal or metal oxide deposition layer, for example, silicon oxide deposited stretched polyethylene terephthalate. Film, Aluminum oxide vapor-deposited stretched polyethylene terephthalate, Aluminum vapor-deposited stretched polyethylene terephthalate film, (c) Others, polyacrylonitrile resin, saponified ethylene vinyl acetate copolymer, polyvinylidene chloride film, polyvinylidene chloride coated biaxially stretched plastic film , MXD6 series nylon (polyamide or polyamide copolymer containing 90 mol% or more of amide structural unit formed by polycondensation reaction of metaxylylenediamine and adipic acid) It become one. A barrier layer having desired performance can be formed by selecting from the above-mentioned barrier materials.
[0039]
The film used as the printing base material layer 15 is not particularly limited as long as it can be generally used. For example, an unstretched or stretched film such as a polyethylene terephthalate, a polypropylene film, or a nylon film can be used.
[0040]
The use of the in-mold label forming label including the barrier layer 14 compensates for the lack of barrier properties of the polyester resin container with respect to gases such as oxygen and carbon dioxide, and causes the contents susceptible to oxygen, such as fruit juice, sake, and wine. It is possible to provide a polyester resin container suitable for packaging such as.
[0041]
In that case, a barrier layer composed of a silicon oxide-deposited plastic film, an aluminum oxide-deposited plastic film, a polyacrylonitrile-based resin, a saponified ethylene-vinyl acetate copolymer, a polyvinylidene chloride film, a polyvinylidene chloride-coated biaxially stretched plastic film, or the like. By using the in-mold label-forming label containing the above, it is possible to provide a polyester resin container having a barrier property without impairing the transparency of the container.
[0042]
In the label for in-mold label molding, a substrate made of a plastic film of the same quality as the resin to be biaxially stretch-blown molded can be used as the base material 12. For example, when the molded article main body is made of polyethylene terephthalate, a silicon oxide-deposited polyethylene terephthalate film is used as a barrier layer, and the printing base material layer laminated on the barrier layer can also be made of polyethylene terephthalate.
[0043]
By using an in-mold label molding label in which the base material 12 is made of a plastic film of the same quality as the resin to be biaxially stretch blow molded, a difference in shrinkage due to a difference in the material of the biaxially stretched blow molded product and the material of the label is caused. Peeling of the label can be prevented.
[0044]
FIG. 5C shows the in-mold label 11 in which the base material 12 is composed of the ultraviolet protection layer 17 and the printing base material layer 15.
[0045]
The ultraviolet absorbing layer 17 is, for example, an unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate, or nylon film provided with a printing layer containing a polysalicylic acid ester, benzophenone, benzotriazole, or acrylonitrile-based ultraviolet absorber. Can be used.
[0046]
By using the label for forming an in-mold label including the ultraviolet absorbing layer 17, it is possible to form a packaging container for contents that are deteriorated by ultraviolet rays, such as a vitamin C-containing food (orange juice).
[0047]
FIG. 5D shows the label 11 for forming an in-mold label, in which the base material 12 includes the barrier layer 14, the ultraviolet ray prevention layer 17, and the printing base material layer 15.
[0048]
The in-mold label forming label 11 provides an in-mold label forming label having a barrier property and an ultraviolet ray preventing function.
[0049]
FIG. 5E shows an in-mold label forming label in which the base material 12 includes the barrier layer 14 and the printing base material layer 15 and further includes the surface protection layer 8. As the surface protective layer 8, a film of polyethylene, polypropylene, polyethylene terephthalate, or the like can be used.
[0050]
In addition, the label of the present invention can be peeled from the biaxially stretched blow-molded article main body by adding an inorganic filler such as silicone, microcrystalline wax, or calcium carbonate to the adhesive layer of the label to form a weakly adhesive layer. The label can be easily peelable. Since the label of this embodiment can be peeled off from the container body, particularly in the case of a polyester resin container, the container body can be recycled after the label for forming the in-mold label is peeled off from the container body when the container is discarded.
[0051]
Next, examples of in-mold label molding labels will be described.
[0052]
1) Stretched polypropylene film (printing substrate layer) (30 μm) / polyethylene terephthalate (12 μm) / stretched silicon oxide vapor-deposited polyethylene terephthalate film (barrier layer) (12 μm) / having heat seal layer containing ethylene-vinyl acetate copolymer Stretched polypropylene film (adhesive layer) (30 μm),
2) Polyethylene terephthalate film (12 μm) / Silicon oxide-deposited polyethylene terephthalate film (12 μm) / Heat sealant layer (adhesive layer) containing ethylene-vinyl acetate copolymer (50 μm)
3) Stretched polypropylene film (printing substrate layer) (25 μm) / aluminum foil (barrier layer) (15 μm) / stretched polypropylene film (25 μm) having a heat seal layer containing ethylene-vinyl acetate copolymer
4) Stretched polypropylene film (printing substrate layer) (25 μm) / silicon oxide-deposited polyethylene terephthalate film (12 μm) (barrier layer) / stretched polyethylene terephthalate film having a heat seal layer containing an ethylene-vinyl acetate copolymer (adhesive layer) ) (25 μm)
5) Stretched polypropylene film (25 μm) / polyethylene terephthalate film (printing substrate layer) (12 μm) / silicon oxide-deposited polyethylene terephthalate film (barrier layer) (12 μm) / having a heat seal layer containing ethylene-vinyl acetate copolymer Stretched polypropylene film (adhesive layer) (25 μm)
6) Stretched polypropylene film (printing substrate layer) (25 μm) / silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / ethylene methacrylic acid copolymer (adhesive layer) (25 μm),
7) Stretched polypropylene film (print substrate layer) (25 μm) / silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / ethylene acrylic acid copolymer (adhesive layer) (25 μm)
8) Stretched polypropylene film (printing substrate layer) (25 μm) / vapor-deposited silicon oxide stretched polyethylene terephthalate film (barrier layer) (12 μm) / hot melt agent layer containing ethylene vinyl acetate copolymer (adhesive layer) (50 μm)
9) Stretched polypropylene film (60 μm) / hot melt agent layer (adhesive layer) containing ethylene vinyl acetate copolymer (25 μm)
10) Stretched polypropylene film (60 μm) / hot melt agent layer (adhesive layer) containing ethylene vinyl acetate copolymer (25 μm).
[0053]
FIG. 6 shows an in-mold label-molded injection-molded container formed by using an in-mold label-molded label having a barrier layer. This container mounts a label for in-mold label molding in an injection molding die, and simultaneously performs a sticking operation of the label on the surface of the injection molded product when the molding material is injected into the injection molding die and molded. The injection molded article 20 is formed by in-mold label molding, and has in-mold label molding labels 21a and 21b on the outside thereof.
[0054]
The injection molded article 20 may be made of polyethylene, polypropylene, polystyrene, or the like.
[0055]
The material of the in-mold label forming labels 21a and 21b generally includes a printing base material layer, a barrier layer, and an adhesive layer with an injection resin. Each of these layers can be formed independently by forming a film and dry-laminating via an adhesive, or by co-extruding a part or all of the layers. Further, the printing base material layer can be omitted depending on the use and purpose.
[0056]
The film as the printing substrate is not particularly limited as long as it is generally printable, and a film made of polyethylene terephthalate, polypropylene, nylon, or the like can be used.
[0057]
As the barrier layer, an unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate or the like, coated with (a) an aluminum foil and (b) a metal or metal oxide vapor deposition layer, for example, silicon oxide vapor-deposited stretched polyethylene terephthalate Film, aluminum oxide-deposited stretched polyethylene terephthalate, aluminum-deposited stretched polyethylene terephthalate film, (c) Others, polyacrylonitrile resin, saponified ethylene vinyl acetate copolymer, polyvinylidene chloride film, polyvinylidene chloride coated biaxially stretched plastic film And MXD6-based nylon. A barrier layer having desired performance can be formed by selecting from the above-mentioned barrier materials.
[0058]
The adhesive layer is not particularly limited as long as it adheres to the injection resin. Usually, a plastic having the same material as the injection resin or an adhesive resin such as polyethylene containing an ethylene-vinyl acetate copolymer is used. An extruded or coated plastic film is suitable.
[0059]
Each of the above layers is formed according to a conventional method, such as a dry lamination method, an extrusion coating method or a coating method.
[0060]
Next, examples of in-mold label forming labels will be described.
1) Stretched polypropylene film (printing substrate) (25 μm) / aluminum foil (barrier layer) (15 μm) / stretched polypropylene film having heat sealing properties (adhesive layer) (25 μm)
2) Stretched polypropylene film (printing substrate) (25 μm) / silicon oxide-deposited polyethylene terephthalate film (barrier layer) (12 μm) / stretched polypropylene film (heat-sealing layer) (adhesive layer) (25 μm),
3) unstretched polypropylene film (30 μm) / polyethylene terephthalate film (printing substrate) (12 μm) / unstretched polypropylene film (adhesive layer) (30 μm),
4) Stretched polypropylene film (25 μm) / polyethylene terephthalate film) (12 μm) / silicon oxide-deposited polyethylene terephthalate film (barrier layer) (12 μm) / stretched polypropylene film (heat-sealing layer) (adhesive layer) (25 μm)
5) Unstretched polypropylene film (30 μm) / polyethylene terephthalate film (printing substrate) (12 μm) / aluminum foil (barrier layer) (9 μm) / polyethylene terephthalate film (12 μm) / unstretched polypropylene film (adhesive layer) (30 μm) .
[0061]
FIG. 7 shows a molded container formed by molding, for example, plug-assist forming a multilayer sheet including a barrier resin layer that can be used as a container body with a flange. In the figure, 32a indicates a container inner layer, 33 indicates a barrier layer, and 32b indicates a container outer layer. As the container inner layer 32a and the container inner layer 32b, a thermoplastic resin such as polyethylene or polypropylene can be used. As the barrier layer 33, a saponified ethylene-vinyl acetate copolymer, a polyvinylidene chloride film, a polyvinylidene chloride-coated biaxially stretched plastic film, or the like can be used.
[0062]
FIG. 8 shows a biaxially stretched polyethylene terephthalate container made of polyethylene terephthalate 41 which can be used as a container body with a flange. In this container, the flange portion is left undrawn.
[0063]
FIG. 9 shows a multilayer injection molded container that can be used as a flanged container body. In the figure, reference numeral 42a denotes a container inner layer, 43 denotes a barrier layer, and 42b denotes a container outer layer. As the container inner layer 42a and the container inner layer 42b, a thermoplastic resin such as polyethylene or polypropylene can be used. As the barrier layer 43, a saponified ethylene-vinyl acetate copolymer, a polyvinylidene chloride film, or the like can be used.
[0064]
In the present invention, the container main body is not limited to the container body with a flange as shown in FIGS. 4, 6 to 9, but may be a container body 42 having a circular annular edge portion 42a as shown in FIG. A container body 43 without a flange as shown in FIG. 11 is also applicable. In the case of the container body 42 shown in FIG. 10, the lid 1 is adhered to the circular annular edge 42a. In the case of the container body 43 of FIG. 11, the lid 1 is adhered to the upper end 43a of the side wall of the container body.
[0065]
Although a container body without a flange is also applicable as described above, it goes without saying that a container body with a flange is more preferable in terms of adhesiveness to a lid material.
[0066]
[Example]
As a label for in-mold label molding, a stretched polypropylene film (printing substrate layer) (30 μm) / polyethylene terephthalate (12 μm) / a silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / ethylene-vinyl acetate copolymer A preform made of polyethylene terephthalate was formed by in-mold labeling using an in-mold label forming label having a layered structure of a stretched polypropylene film (adhesive layer) (30 μm) having a heat-sealing layer including the heat-sealable layer to form a flanged cup container. In addition, polyethylene terephthalate 12 μm / aluminum foil is bonded to an oxygen absorbing layer 30 μ) / ethylene-propylene copolymer olefin (EP-W) 60 μm using an adhesive (RU40 / H-4). A lid having a layer structure of 7 μ / adhesive layer / oxygen absorbing layer 30 μ / ethylene-propylene copolymer olefin (EP-W) 60 μm was obtained.
[0067]
Juice heated at 90 ° C. for 5 seconds and sterilized by heating at 90 ° C. is chill-filled at a temperature of 10 ° C. or less, and the lid is placed over the opening of the flanged container body. Thermal bonding was performed at a sealing temperature of ° C. The package in which the container body with the flange was sealed with the lid was stored at a temperature of 10 ° C. or less for one month. During storage, as the oxygen in the headspace was absorbed by the oxygen absorbing layer of the lid, the lid was dented and deformed so that its center was drawn toward the headspace.
[0068]
The package was placed in a hot warmer and warmed to about 55-60 ° C. At this time, the lid was slightly expanded so that the center of the lid protruded about 1.5 mm from the periphery of the lid, but the lid did not peel off from the flange. After warming with a hot warmer, the lid was peeled from the flange. The sealant layer of the lid was able to be peeled off from the flange surface and opened without exposing the iron powder contained in the oxygen absorbent by leaving the sealant on the flange surface.
[0069]
[Comparative example]
A package filled with chilled food was prepared in the same manner as in Example, except that a lid having a layer constitution of polyethylene terephthalate 12 μ / aluminum foil 7 μ / polyethylene sealant 40 μm without an oxygen absorbing layer was used as the lid. After storing the package at 10 ° C. or lower for one month, the package was placed in a hot warmer and heated. As a result, a phenomenon was observed in which the lid bulged greatly and the lid was peeled off from the flange.
[0070]
【The invention's effect】
As described in detail above, the packaging container of the present invention includes a container body having a barrier property and a lid, and the lid includes a laminate including at least a barrier layer, an oxygen absorbing layer and a sealant layer, and The layer absorbs the oxygen in the headspace and the dissolved oxygen in the package contents that come out of the headspace during heating by the hot warmer, reduces the headspace by the amount of oxygen absorbed, and sells with heating. In addition, there is an advantage that deformation of the lid or peeling from the container body due to an increase in internal pressure in the container and an increase in head space are prevented.
[0071]
Further, according to the package using the packaging container of the present invention, during heating by the hot warmer, the nitrogen in the head space expands and the remaining dissolved oxygen comes out of the contents, thereby increasing the internal pressure in the container. Although the head space becomes large, the lid is restored to a flat state or the center of the lid is slightly deformed so as to expand about 1.5 mm with respect to the peripheral edge of the lid, and the commercial value is impaired. The lid can be prevented from being deformed or peeled off, so that the lid can be heated and sold by a hot warmer.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view for explaining the structure and function of a package of the present invention. FIG. 1 (A) is a schematic side view of the package of the present invention, and FIG. The schematic side views shown, (C) and (D) are schematic side views of the package after being warmed in a hot warmer.
FIG. 2 is a sectional view showing a configuration of a lid.
FIG. 3 is a cross-sectional view showing another configuration of the lid.
FIG. 4 is a cross-sectional view of an in-mold label-formed biaxially stretched blow container used as a container body with a flange of a package of the present invention.
5A and 5B show a label for forming an in-mold label, FIG. 5A is a cross-sectional view showing a basic configuration of the label for forming an in-mold label, and FIG. 5B is a cross section showing a first example of the label for forming an in-mold label. FIG. 1C is a cross-sectional view showing a second example of the label for forming an in-mold label, FIG. 2D is a cross-sectional view showing a third example of the label for forming an in-mold label, and FIG. It is sectional drawing which shows the 4th example of a label for label forming.
FIG. 6 is a sectional view of an in-mold label injection molded container used as a flanged container body of the package of the present invention.
FIG. 7 is a cross-sectional view of a container formed from a multilayer sheet used as a flanged container body of the package of the present invention.
FIG. 8 is a cross-sectional view of a biaxially stretch blow-molded container of polyethylene terephthalate used as a flanged container body of the package of the present invention.
FIG. 9 is a cross-sectional view of a multilayer injection-molded container used as a container body with a flange of the package of the present invention.
FIG. 10 is a cross-sectional view showing a container body with a circular annular edge used as a container body of the package of the present invention, together with a lid member.
FIG. 11 is a cross-sectional view showing a container body without a flange used as a container body of the package of the present invention together with a lid member.
[Explanation of symbols]
1, 1a, 1c Lid
2 Container body with flange
2a flange
3 Package contents
4 Headspace
5, 5a protective layer
6 Barrier layer
7, 7a adhesive layer
8 Oxygen absorption layer
9 Sealant layer
10 Biaxially stretched blow molded products
11 In-mold label molding label
12 Substrate
13 Adhesive layer
14 Barrier layer
15 Printing base material layer
16 Printing pattern layer
17 UV protection layer
18 Surface protective layer
20 Injection molded products
21a, 21b In-mold label molding label
32a Container inner layer
32b Container outer layer
33 Barrier layer
41 Polyethylene terephthalate
42 Container body
42a Round annular edge
43 Container body
43a Upper end of side wall

Claims (14)

A packaging container comprising a container main body having a barrier property and a lid, wherein the lid comprises a laminate having at least a barrier layer, an oxygen absorbing layer, and a sealant layer. The packaging container according to claim 1, wherein the lid includes a protective layer made of plastic or paper outside the barrier layer. 3. The packaging container according to claim 1, wherein the sealant layer of the lid is made of an ethylene-propylene copolymer olefin resin. The container body having a barrier property is an in-mold label biaxial stretch blow-molded container or an in-mold label injection molded container formed using an in-mold label molding label having a barrier layer. 4. The packaging container according to any one of 3. The packaging container according to any one of claims 1 to 3, wherein the container body having a barrier property is a multilayer injection-molded container including a barrier resin layer. The packaging container according to any one of claims 1 to 3, wherein the container body having a barrier property is a molded container formed by molding a multilayer sheet including a barrier resin layer. The packaging container according to any one of claims 1 to 6, wherein the container body is a flanged container body. The packaging container according to any one of claims 1 to 6, wherein the container body is a container body having a round annular edge. The packaging container according to any one of claims 1 to 6, wherein the container body is a container body without a flange. The food packaging container according to claim 7, wherein the sealing temperature of the lid to the flange surface of the container body is 230C, preferably 180C or less. The food packaging container according to claim 8, characterized in that the sealing temperature of the lid to the round annular edge of the container body is 230C, preferably 180C or lower. The food packaging container according to claim 9, wherein a sealing temperature of the lid to the upper end portion of the side wall of the container body is 230C, preferably 180C or lower. The packaging container according to any one of claims 1 to 12, wherein the container body is filled with food as a packaging content, a head space exists on the packaging content, and a mouth portion of the container body. Is a package sealed by a lid. The package according to claim 7, wherein the package contents are foods filled at room temperature in a container body, chilled or sold at room temperature, and eaten at a temperature of 45 to 70C.

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