JP4662451B2 - Sealed container for boil and retort - Google Patents

Description

  The present invention relates to a sealed container for boil and retort. More specifically, the function of absorbing oxygen from the outside, oxygen remaining in the packaging bag and dissolved oxygen, oxygen barrier properties, quality storage suitability, heat resistance, water resistance, pressure resistance, and easy opening properties The present invention relates to a sealed container for boil and retort that can withstand the boil and retort treatment in a state where the contents such as food are stored and the flange portion of the container is sealed with a lid.

Conventionally, contents such as solid or liquid foods and drinks, cosmetics, medicines, miscellaneous goods, etc. are stored in a synthetic resin molded container, and the opening is sealed with a lid, and distributed and stored. .
The molded container is filled with and packaged with food such as soup, milk, coffee, tea, fruit juice drink, etc., and sealed with a lid, and is distributed and sold at chilled or normal temperature. In addition, it is sold in a hot warmer installed in a convenience store or the like after being heated to a drinking temperature of about 45 ° C. to 70 ° C.

  The synthetic resin molded container has a multilayered structure for the container wall for the purpose of giving the container body a gas barrier function to block oxygen permeation from the outside, an ethylene-vinyl alcohol, an outer layer made of a thermoplastic resin There is known a molded container having a multilayer structure in which an intermediate layer made of a gas barrier layer such as a copolymer and an inner layer made of a thermoplastic resin are laminated.

  However, even if a gas barrier function is added to the molded body of the synthetic resin, oxygen in the air remains in the container when the food is filled. Is deteriorated, and there is a problem that the commercial value is impaired.

In addition, in the case of a package body filled with contents such as food in the above-mentioned synthetic resin molded container and sealed with a lid, after filling the molded container with food and sealed with a lid, during retort or boil processing, Alternatively, the gas barrier performance of the ethylene-vinyl alcohol copolymer is lowered during heating by a hot warmer, and the gas barrier performance is recovered at room temperature and in a dry state within a few days after the retort or boil treatment.
For this reason, during heating with a hot warmer, or after retort or boil treatment, oxygen enters from the outside of the container within a few days, and this oxygen oxidizes the food, causing discoloration and components of the food to deteriorate, resulting in commercial value. There is a problem that is damaged.

As a molded container that prevents oxygen permeation from the outside and interposes a layer containing an oxygen absorbent in the layer of the laminated material, thereby imparting a function of absorbing oxygen and the like remaining in the container, The layer structure of the molded container body is a heat-sealable thermoplastic resin inner layer from the inner surface side toward the outer surface side, a thermoplastic resin layer containing a metal powder having reducing properties such as reducing iron as an oxygen absorbent, heat A sealed container made of a laminate container material of a plastic resin cushion layer, an oxygen barrier layer, and a heat resistant resin outer layer has been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-40024

However, in the sealed container of Patent Document 1, when the lid is peeled off and opened, the lid is poorly opened, and the iron powder constituting the thermoplastic resin layer containing the oxygen absorbent is exposed on the surface. There is a risk that the appearance will be damaged.
In addition, with emphasis on the openability of the sealed container, if an easy peel sealant material is used on the peeling surface of the lid, or if a weak seal is created by changing the sealing conditions between the lid and the container, retort or boil treatment will occur. Under such severe conditions, there is a problem that the lid material may be opened during the boil / retort treatment, or that delamination may occur, causing liquid leakage.

  An object of the present invention is to absorb oxygen penetrating into a molded container during retort or boil treatment, prevent discoloration or deterioration of ingredients due to oxidation of food, have excellent contents storage suitability, and open the lid. It is an object of the present invention to provide a sealed container for boil and retort that is easy to perform and can withstand severe conditions such as retort and boil treatment.

To solve the above problems, in a boiling or retorting sealed container according to the present invention, gas barrier molded container, and sealed containers for boiling or retorting made therefrom in the lid that is heat sealed storing contents, The gas barrier molded container has a configuration in which an outer layer made of a thermoplastic resin, a gas barrier intermediate layer made of a gas barrier thermoplastic resin, and an inner layer made of a thermoplastic resin layer are sequentially laminated from the outside. The outer layer is made of a polypropylene resin, and the gas barrier intermediate layer is an ethylene-vinyl alcohol copolymer, a nylon resin layer, an ethylene-vinyl alcohol copolymer layer, and a nylon resin layer, and a nylon resin layer. And coextruded resin layer consisting of MXD nylon resin layer and nylon resin layer, or MXD nylon resin layer , Made from the cover material surface peelable thermoplastic resin layer of the inner layer, the gas barrier molded container is a deep-drawn container obtained by vacuum-pressure forming, the lid member is from the outside, heat-resistant substrate Oxygen absorption composed of a heat-resistant outer layer made of a film, a pinhole- resistant intermediate layer for imparting pinhole resistance , a gas barrier intermediate layer made of aluminum foil or an aluminum vapor-deposited layer, and a thermoplastic resin layer containing iron powder and sex intermediate layer, composed of a multilayer structure including a heat sealable inner layer comprising a thermoplastic resin layer, from the oxygen-absorbing intermediate layer is the pinhole resistance intermediate layer and the gas barrier intermediate layer, positioned on the contents side and, heat sealable inner layer is polypropylene resin of the cover member made of a high density polyethylene resin, medium density polyethylene resin or a linear low-density polyethylene resins, the molding Vessel accommodates a 78% of water volume of the molding vessel, after nitrogen substitution, after retort sterilization in a sealed container state where the lid member is thermally sealed, it is 3 months storage at 23 ° C., the sealing The oxygen concentration (%) of the head space in the container measured with a zirconia oxygen analyzer is 5% or less .

  The sealed container is a boil sterilization container that can withstand a boil sterilization process in warm water at 70 to 100 ° C., or a retort sterilization container that can withstand a retort sterilization process at 100 to 135 ° C. It is characterized by being.

  The sealed container for boil and retort according to the present invention absorbs oxygen that penetrates into the molded container after the boil and retort treatment, oxygen that penetrates into the molded container by heating with a hot warmer, and oxygen that remains in the container. It is possible to prevent discoloration and component deterioration due to oxidation, excellent contents storage suitability, easy to open the lid by hand, and peeling off on the flange surface without exposing the iron material constituting the intermediate layer In addition, even under severe conditions such as retort or boil treatment, there is no delamination, unsealing, etc., and there is an advantage that it can withstand retort or boil treatment.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
First, the structure of a laminated material or the like constituting the sealed container for boil / retort according to the present invention will be described with reference to the drawings, illustrating one example thereof. FIG. 1 shows the laminated structure constituting the lid according to the present invention. 2 is a laminated material constituting the gas barrier molding container according to the present invention, FIG. 3 is a sectional view of the sealed container 100 for boil and retort according to the present invention, and FIG. It is a figure which shows the structure of the lid | cover material of the packaging body of invention which can be boiled and retorted, and the heat bonding part of a container, (a) is sectional drawing of the state which adhere | attached, (b) is sectional drawing of the state which peeled the lid | cover.

FIG. 1 shows a laminated material constituting a lid 10 according to the present invention.
As shown in FIG. 1, the lid 10 according to the present invention includes an outer layer 2 made of a heat-resistant base film, an adhesive layer 3, an intermediate layer 4 made of aluminum foil as a gas barrier layer, and bonded from the outside. It is comprised from the laminated body which laminates | stacks the agent layer 5, the intermediate | middle layer 6 which consists of a thermoplastic resin layer containing an oxygen absorber, and the inner layer 8 which consists of a thermoplastic resin layer one by one.
Although not shown, the lid 10 according to the present invention can be further laminated with a layer imparting pinhole resistance in FIG.
The lid member 10 according to the present invention is capable of blocking oxygen from the outside, absorbing oxygen penetrating into the molded container during retort or boil treatment, and oxygen remaining in the container, and the retort. In addition, there is an advantage that the lid body is not opened and the lid body is not peeled off even under severe conditions such as boil treatment, has heat resistance and pressure resistance, and can be peeled off from the flange.

As the heat-resistant base film (outer layer) 2 constituting the lid 10 according to the present invention, since it becomes a basic material of the lid 10, after sealing the molded container, from the physical impact from the outside, the packaging material, A resin film or sheet having impact resistance for protecting the contents, heat resistance to withstand heat sealing, and printability can be used.
Specifically, for example, polyester resin, polyamide resin, polyaramid resin, polyolefin resin, polycarbonate resin, polystyrene resin, polyacetal resin, fluorine resin, etc. A resin film or sheet, or the like can be used.
Further, if necessary, a metal such as aluminum or an inorganic material such as aluminum, alumina oxide or silicon oxide may be vapor-deposited on these base films.
If necessary, for example, a desired printing pattern such as a character, a figure, a symbol, a pattern, or a pattern may be subjected to surface printing or back printing with a normal printing ink.
As the resin film or sheet, any of an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction can be used.
The thickness of the film is about 5 to 100 μm, preferably about 10 to 50 μm.

As a layer (intermediate layer) imparting pinhole resistance that constitutes the cover material 10 according to the present invention, it exhibits excellent properties in mechanical, physical, chemical, etc., has excellent strength, A film or sheet having excellent physical properties such as heat resistance, pinhole resistance and puncture resistance can be used.
Specifically, the material for the layer imparting pinhole resistance is a tough resin such as polyamide resin, polyethylene resin, polypropylene resin, polyester resin, polyaramid resin, polycarbonate resin, polyacetal resin, fluorine resin, or the like. A film or sheet can be used.
Thus, as the resin film or sheet, any of an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction can be used.
In the present invention, the thickness of the resin film or sheet may be a thickness that can be kept to the minimum necessary for strength, pinhole resistance, puncture resistance, rigidity, etc., and is too thick. In addition, there is a disadvantage that the cost increases. On the other hand, if it is too thin, the strength, puncture resistance, rigidity, etc. are undesirably lowered.
The thickness of the film is about 5 to 100 μm, preferably about 6 to 50 μm.

As the layer (intermediate layer) 4 that imparts gas barrier properties constituting the lid member 10 according to the present invention, a material having a property that does not transmit water vapor, water, gas, or the like can be used. A base material may be sufficient and the composite base material etc. which combined 2 or more types of base materials may be sufficient.
Specifically, as a material for this barrier layer, aluminum foil, metal such as aluminum, ceramic such as silica and alumina is used by forming a deposited film on a plastic film such as PET film by vacuum deposition or sputtering. There is also.
In addition to these, indium tin oxide (ITO), metal oxides such as zinc, tin, titanium, zirconium, vanadium, barium, chromium, silicon nitride, silicon carbide, and the like can be used as the ceramic.
These materials can be used alone or in combination.
In addition, the resin film that supports the above-described vapor-deposited film is provided with a vapor-deposited layer, and therefore has excellent properties in mechanical, physical, chemical, etc., particularly strong and tough. In addition, a heat-resistant resin film or sheet can be used.
The thickness of the above film or sheet is arbitrary, but is usually preferably about 5 to 300 μm, and more preferably about 10 to 100 μm.
Furthermore, in the above, it is preferable to use an aluminum foil having a thickness of about 5 to 30 μm, and a metal or inorganic oxide deposition film having a thickness of about 50 to 3000 mm, preferably 100 to A thing of about 1000 mm is desirable.
In the lid material 10 according to the present invention, among them, the lid material laminated with an aluminum foil is very excellent in gas barrier properties under the wet state of the reboiling / retort treatment process, and has a property of blocking light from the outside. It has excellent storability of contents.
In addition, the lid material laminated with aluminum foil can hold eclectic on the lid so that it can stand up when the hot water is poured into the cup container and then the container lid is opened and then resealed. It is preferable because it is possible. That is, a lid material laminated with an aluminum foil is preferable because it has the property of maintaining the opened state and maintaining the opened state even when the lid is raised and opened.
In addition, since it has a property that hardly causes curling, it is preferable because workability such as automatic supply is good particularly when heat-sealing a container as a single-sheet lid.

The intermediate layer 6 imparting an oxygen-absorbing function that constitutes the lid member 10 according to the present invention is composed of a thermoplastic resin layer containing an oxygen-absorbing material.
As the oxygen absorbent, all conventionally used oxygen absorbents can be applied, but generally those which are reducible and substantially insoluble in water are preferable.
Specifically, for example, metal powder having reducibility such as reducible iron, reductive zinc, reductive tin powder, for example, low metal oxides such as ferrous oxide and iron tetroxide, such as iron carbide, A reducing metal compound or the like mainly composed of one or a combination of two or more of silicon iron, iron carbonyl, ferrous hydroxide and the like can be used.
These oxygen absorbers can be combined with auxiliary agents such as alkali metal, alkaline earth metal hydroxide, carbonate, sulfite, thiosulfate, tertiary phosphate, activated alumina, activated clay as necessary. Can be used.
In general, these oxygen absorbers preferably have an average particle size of 50 μm or less because a smooth oxygen-absorbing layer can be obtained, and more preferably 30 μm or less.
Further, the oxygen absorbent is preferably 1 to 90 parts by weight per 100 parts by weight of the following resin, and is preferably added to the thermoplastic resin layer at a ratio of 10 to 50 parts by weight.
If the oxygen absorbent is less than 1 part by weight, the oxygen absorbing function is not exhibited, which is not preferable, and if it exceeds 90 parts by weight, the film formability is inferior.

As the thermoplastic resin layer 6 containing an oxygen absorbent, it is necessary to be a resin capable of forming a film and capable of withstanding a boil / retort sterilization treatment. (Linear) low density polyethylene resin (preferably having a density of 0.92 or more), medium density polyethylene resin, high density polyethylene resin, ethylene-α / olefin copolymer polymerized using metallocene catalyst, iso Tactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, polyester resin, ion-crosslinked olefin copolymer Resin consisting of polymer (ionomer) or blends of these can be used. The
For the above resin, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyvinyl methyl ether, polyvinyl alcohol, vinyl alcohol-acrylic acid copolymer, polyethylene oxide modified product, sodium acrylate heavy Superabsorbent resins such as starch, cellulose-based graft derivatives such as coalescence, acrylic acid, acrylate, grafted starch, starch acrylonitrile grafted hydrolyzate, acrylic acid grafted cellulose, acrylate grafted cellulose, etc. Can be added as a water-absorbing agent.
In addition to these resins, inorganic salts such as sodium sulfate, magnesium sulfate, disodium phosphate, and sodium diphosphate, and water-absorbing inorganic compounds such as silica gel, alumina gel, diatomaceous earth, and various zeolites can be blended.
Moreover, you may add coloring agents, such as dye and a pigment, a dispersing agent, antioxidant, an antistatic agent, a lubricant, etc. to said resin as needed.

As the inner layer 8 constituting the lid 10 according to the present invention, it can be heat-sealed to the flange of the container body, can withstand boil / retort sterilization treatment, and adheres firmly to the oxygen-absorbing layer (intermediate layer 6), When the lid is opened by hand, a thermoplastic resin layer that can be peeled off from the flange without delamination or cohesive failure between the oxygen-absorbing layer and the inner layer can be used.
Specific examples of the resin constituting the thermoplastic resin layer include, for example, a linear (linear) low density polyethylene resin (preferably having a density of 0.92 or more), a medium density polyethylene resin, and a high density. Polyethylene resin, ethylene-α-olefin copolymer polymerized using metallocene catalyst, isotactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 A resin comprising a copolymer, an ethylene-propylene-butene 1 copolymer, a polyester resin, an ion-crosslinked olefin copolymer (ionomer), or a blend thereof can be used.
In the above resin, it is preferable to use the same resin as the intermediate layer 6 that imparts an oxygen-absorbing function in terms of excellent interlayer adhesion between the oxygen-absorbing layer and the inner layer. It can be laminated by coextrusion.

  Further, since the oxygen absorbing layer is colored with an oxygen absorbent, it is preferable to color by blending a conventionally known white pigment such as titanium white so as to conceal the oxygen absorbing layer.

The method of laminating the layers constituting the lid 10 according to the present invention will be described. Dry lamination method, solventless lamination method, wet lamination method, extrusion lamination method, coextrusion lamination method, sandwich lamination method, etc. Among them, the dry lamination method is preferable.
In the present invention, by using a laminating adhesive, the adhesion between each layer is improved, the elongation of the laminating adhesive layer is improved, the post-processing suitability for laminating is improved, and the post-processing is improved. It is advantageous in that cracking of a metal foil such as aluminum can be prevented, and even if boil treatment or retort treatment is performed, the laminate strength becomes strong without delamination.
When performing the above lamination, if necessary, pretreatment such as corona treatment and ozone treatment can be applied to the film.
The composition system of the above adhesive for laminating may be any form such as an aqueous type, a solvent type, an emulsion type, and a dispersion type, and the properties are film / sheet type, powder type, solid type, etc. Further, the bonding mechanism may be any form such as a chemical reaction type, a solvent volatilization type, a heat melting type, and a hot pressure type.
Examples of such adhesives for laminating include, for example, anchor coating agents such as isocyanate (urethane), polyethyleneimine, polybutadiene, and organic titanium, or polyurethane, polyethyl acrylate, Polyacrylic such as polybutyl acrylate and 2-ethylhexyl ester, polyester, epoxy, polyvinyl acetate, cellulose, polyamide, polyimide, urea resin, melamine resin, amino resin, phenol resin -Based, epoxy resin-based, reactive (meth) acrylic-based, chloroprene rubber, nitrile rubber, styrene-butadiene rubber and other rubber systems, silicone-based, alkali metal silicates, low-melting glass inorganic adhesives, etc. Adhesives and the like can be preferably used. For example, isocyanate resin And curing agent), polyester resin having a hydroxyl group, polyether-based resin, urethane-modified polyol, two-component curable adhesive and an epoxy compound (base resin) is preferable.
Among these, it is preferable to use polyester from the viewpoint of heat resistance.
In addition, for example, an adhesion promoter such as a silane coupling agent can be arbitrarily added to the laminating adhesive.
The silane coupling agent hydrolyzes a functional group, chloro, alkoxy, or acetoxy group at one end of the molecule to form a silanol group, which is on the surface of the metal foil, metal, or inorganic oxide vapor deposition film. The organic functional group such as vinyl group, methacryloxy group, amino group, and epoxy group at the other end of the silane coupling agent is resistant to the dehydration condensation reaction with the active group of the silane coupling agent. By strongly reacting with the substances constituting the pinhole layer, the innermost layer, etc., the laminate strength is increased and a strong interlayer strength is made possible.
That is, utilizing the inorganic and organic properties of the silane coupling agent, through a metal foil, an inorganic oxide vapor deposition film, an adhesive layer, an anchor coating agent layer, and other layers, a paper substrate, Adhesiveness with a synthetic resin film base material is improved, thereby increasing the laminate strength.
And, as a method for forming these adhesives, for example, direct roll coat, reverse roll coat, gravure (direct) coat, air knife coat, squeeze coat, blade coat, comma coat, curtain flow coat, kiss coat, extrusion coat, It can be formed by other methods.
The coating amount of the ^{adhesive, 0.1g / m 2 ~10g / m} 2 of (dry) are ^{preferred, 1g / m 2 ~5g / m} 2 of (dry) is desirable.

FIG. 2 shows a laminated material constituting the gas barrier molding container 20 according to the present invention.
As shown in FIG. 2, the gas barrier molding container 20 according to the present invention includes, from the outside, an outer layer 12 made of a thermoplastic resin, an intermediate layer 14 made of a gas barrier thermoplastic resin, and an inner layer 16 made of a thermoplastic resin layer. Are sequentially stacked.
The outer layer 12 and the inner layer 16 made of a thermoplastic resin constituting the gas barrier molding container 20 according to the present invention can be used as a resin for deep drawing formed by vacuum / pressure forming and can be boiled / retorted. For example, polyethylene resins such as high density polyethylene, medium density polyethylene, low density polyethylene, linear (linear) low density polyethylene, pomopolypropylene resin, propylene-ethylene random copolymer, propylene -Ethylene block copolymer, polypropylene resin such as the copolymer, polystyrene resin, butadiene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, (meth) acrylic resin, polyester resin, polyamide Resin, polycarbonate resin, etc. These various molding resins can be used.
In the present invention, in order to satisfy the function, strength, etc. as a packaging container, it is more preferable to use polypropylene resin or high-density polyethylene resin.

The intermediate layer 14 made of a gas barrier thermoplastic resin constituting the gas barrier molding container 20 according to the present invention is a resin having a gas barrier property that prevents permeation of oxygen gas, water vapor, etc., and is formed by vacuum / pressure forming. For example, polyester resins, polycarbonate resins, nylon resins (polyamide resins), acrylonitrile resins, polyvinyl alcohols are required. Film, sheet of resin such as saponified resin, ethylene-vinyl acetate copolymer, etc. In addition, colorants such as pigments are added to the resin and other additives are kneaded to form a film. Various colored resin films or sheets having light shielding properties can be used in combination. These materials can be used alone or in combination. The thickness of the above-mentioned film or sheet is arbitrary, but is usually about 6 μm to 100 μm, more preferably about 7 μm to 30 μm. Further, in the above, as the vapor-deposited thin film of inorganic oxide, one having a thickness of about 50 to 1000 mm can be used. Examples of the resin film that supports the vapor-deposited film include, for example, a polyester film, a polyamide film, a polyolefin film, a polycarbonate film, a polyvinyl alcohol film, an ethylene-vinyl acetate copolymer saponified film, and the like. Can be used.
In the present invention, among others, an ethylene-vinyl alcohol copolymer, a coextruded resin layer comprising a nylon resin layer, an ethylene-vinyl alcohol copolymer layer, and a nylon resin layer, a nylon resin layer, an MXD nylon resin layer, and nylon A co-extruded resin layer made of a resin layer or an MXD nylon resin layer is preferred because it is excellent in water resistance and heat resistance when performing a boil / retort treatment.
The ethylene-vinyl alcohol copolymer preferably has an ethylene content of about 20 mol% to 60 mol%, and the ethylene vinyl alcohol copolymer having a mol content of 25 mol% to 50 mol% has a saponification degree of 95% or more. An ethylene vinyl alcohol copolymer which is a saponified copolymer obtained by saponification can be used.
When the ethylene content is less than 20 mol% or the saponification degree is less than 95%, the gas barrier property under high humidity is inferior, and when the ethylene content exceeds 60 mol%, not only under high humidity, Even under low humidity, the gas barrier property is poor, which is not preferable.

The gas-barrier molded container 20 according to the present invention is not particularly limited as long as it is a thermoplastic resin as the easily openable thermoplastic resin layer that forms the surface of the flange portion. , Polyethylene resins such as medium density polyethylene, low density polyethylene, linear (linear) low density polyethylene, pomopolypropylene resin, propylene-ethylene random copolymer, propylene-ethylene block copolymer, copolymer thereof Polypropylene resin, polystyrene resin, butadiene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, (meth) acrylic resin, polyester resin, polyamide resin, polycarbonate resin, etc. Various molding resins such as can be used.
In the present invention, a resin in which the above resins are used alone or in combination can be used.
Specifically, it is preferable to form a half cut cut into the resin layer that forms the surface of the flange portion of the container so as not to reach the barrier layer as the intermediate layer. For example, the product name “magic top” ( Idemitsu Unitech Co., Ltd.). This makes it easy to cut the resin layer from the half-cut forming portion, which is preferable in terms of easy opening.

If necessary, colorants such as dyes and pigments, dispersants, antioxidants, antistatic agents, lubricants and the like may be added to the above resins.
Each of the above layers is laminated by a coating method such as a dry lamination method or a coextrusion coating method.

  The laminated film or sheet obtained above can be used as a thermoformed container by a forming method such as vacuum forming or pressure forming.

From the opening, the gas barrier molded container 20 according to the present invention is a fluid food such as rice cake, jelly-like food, liquid soup, milk, coffee, tea, fruit juice, seasoning, curry, stew. -Filled with various foods and beverages such as meat sauce, etc., cosmetics, pharmaceuticals, chemicals, etc., and then using a lid on the opening, heat seal, etc. To produce a hermetically sealed package, and the above-mentioned hermetically sealed package is, for example, about 70 minutes to 100 degrees Celsius, depending on the contents, for about 3 minutes to 60 minutes. For example, at a temperature of about 100 ° C. to 135 ° C., a pressure of about 1 kgf / cm ^{2 to 3} kgf / cm ² , or about 10 minutes to 60 minutes. Retort by retort sterilization method Sense or in boiling treatment, in which it is possible to produce packaging products retort to boil treatment.
The retort sterilization temperature is usually 120 ° C. under retort conditions of about 30 to 60 minutes, but may be carried out with a semi-retort of 105 ° C. to 115 ° C., a high retort (HTST) of 130 ° C. or higher, and the like. it can.

Next, the sealed packaging container 100 for boil and retort according to the present invention will be described more specifically with reference to examples.
[Production of gas barrier container body 20]
As laminated sheet for gas barrier container molding, layer constitution, (outside) polypropylene resin layer (thickness 790 μm) / adhesive resin layer (thickness 20 μm) / ethylene-vinyl alcohol copolymer layer (thickness 120 μm) / adhesive resin Using the product name “Magic Top SMP”, manufactured by Idemitsu Unitech Co., Ltd., with a layer (thickness 20 μm) / polypropylene resin layer (thickness 790 μm) / easy-opening thermoplastic resin layer (thickness 60 μm) (inside) A gas barrier molded container 20 having a diameter of 88 mm and a volume of 230 ml (full capacity) was prepared by the method.
In addition, the thermal bonding scheduled part of the lid member was formed so as to be provided with a space having a width of at least 4 mm. The flange around the opening of the container is provided with a half cut inside the lid 10 and the portion to be thermally bonded.
[Fabrication of lid 10]
As the lid member 10, from the outside, a biaxially stretched polyethylene terephthalate film layer (thickness 12 μm), a biaxially stretched nylon film (thickness 15 μm), an aluminum foil (thickness 7 μm), and a polypropylene resin with an average particle size of 30 μm A two-component curable polyurethane adhesive comprising an oxygen-absorbing material layer (thickness 30 μm, trade name “Omak”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and an unstretched polypropylene resin layer (thickness 40 μm) formed by kneading iron powder. Layered, laminated, laminated, biaxially stretched polyethylene terephthalate film layer (thickness 12 μm) / two-component curable polyurethane adhesive layer / biaxially stretched nylon film (thickness 15 μm) / two-component curable polyurethane Adhesive layer / aluminum foil (thickness 9 μm) / two-component curable polyurethane adhesive layer / oxygen absorber property Was produced (thickness 30 [mu] m) / an unstretched polypropylene resin layer (thickness 40 [mu] m).
[Preparation of sealed package 100 for boil and retort]
As the contents 30 to be filled and packaged from the opening into the gas barrier molded container 20 manufactured as described above, the soup is filled, and the air inside the package is replaced with nitrogen gas. It sealed with the manufactured lid | cover material 10, and heat-sealed from the outer side, and manufactured the sealed package body.
Next, the above sealed package is put into a retort kettle and subjected to retort treatment (heat sterilization treatment) under retort treatment conditions consisting of temperature, 125 ° C., pressure, 2.1 kgf / cm ² , time, 60 minutes, and retort treatment. Finished packaging products.
The above retort-treated packaged product can absorb oxygen that penetrates into the molded container and remains in the headspace of the container during boil / retort treatment and warming with a hot warmer, and the food is oxidized. Because it can prevent discoloration and component deterioration, it has excellent contents storage suitability, and there is no delamination or deformation of the container after retort processing, and it is easy to pinch the knob on the lid when opening the sealed container It was easy to open and peeled off from the flange surface of the container main body without exposing the iron material constituting the intermediate layer, so that the appearance was excellent.

Using the same gas barrier container body 20 and lid body 10 as in Example 1 above, the contents 30 were filled with coffee instead of soup, and the air inside the package was replaced with nitrogen gas. The sealed package 100 according to Example 2 was manufactured by sealing the opening with the lid material manufactured above and heat-sealing from the outside.
Next, the above sealed package is put into a retort kettle and subjected to retort treatment (heat sterilization treatment) under retort treatment conditions consisting of temperature, 125 ° C., pressure, 2.1 kgf / cm ² , time, 60 minutes, and retort treatment. Finished packaging products.
The retort-treated packaged product 100 is stored in a hot-warmer (60 ° C.) after being boiled and retorted for 1 week and then stored at 23 ° C. for 2 weeks. Because it can absorb oxygen penetrating into the interior and oxygen remaining in the head space of the container, it can prevent discoloration and component deterioration due to oxidation of the food, so the taste and flavor of the coffee content does not deteriorate, It has excellent storage suitability, and after retorting, there is no delamination or deformation of the container, and when opening the sealed container, it is easy to pinch the knob part of the lid and easily expose the iron material constituting the intermediate layer. Since it peels on the flange surface of the container main body, the appearance was excellent.

In the layer structure of the lid 10 of the sealed packaging container for boil and retort in Example 1 above, an aluminum vapor deposition layer having a thickness of 100 mm is formed on one side of a 12 μm thick biaxially stretched polyethylene terephthalate film instead of the aluminum foil. Except for using the deposited film, a layer structure, a biaxially stretched polyethylene terephthalate film layer (thickness 12 μm) / aluminum deposited film (100 mm) / two-component curable polyurethane adhesive layer / A biaxially stretched nylon film (thickness 15 μm) / two-component curable polyurethane adhesive layer / oxygen absorbent layer (thickness 30 μm) / unstretched polypropylene resin layer (thickness 40 μm) was produced.
After filling the contents of the lid body prepared above into the same gas barrier container body as in Example 1, the atmosphere was replaced with nitrogen, heat sealed at the flange portion, the container was sealed, placed in the retort kettle, and the temperature, 125 A retort treatment (heat sterilization treatment) was performed under retort treatment conditions consisting of ° C., pressure, 2.1 kgf / cm ² , time, and 60 minutes, to produce a retort-treated packaged product 100 according to Example 3.
The above retort-treated packaged product can absorb oxygen that penetrates into the molded container and remains in the headspace of the container during boil / retort treatment and warming with a hot warmer, and the food is oxidized. Because it can prevent discoloration and component deterioration, it has excellent contents storage suitability, and there is no delamination or deformation of the container after retort processing, and it is easy to pinch the knob on the lid when opening the sealed container It was easy to open and peeled off from the flange surface of the container main body without exposing the iron material constituting the intermediate layer, so that the appearance was excellent.

(Comparative Example 1)
In the layer structure of the lid 10 of the sealed packaging container for boil and retort in Example 1, all the same as Example 1 except that the oxygen absorbent material layer formed by kneading iron powder with polypropylene resin is not formed. Layer configuration, biaxially stretched polyethylene terephthalate film layer (thickness 12 μm) / two-component curable polyurethane adhesive layer / biaxially stretched nylon film (thickness 15 μm) / two-component curable polyurethane adhesive layer / aluminum foil (Thickness 7 μm) / two-component curable polyurethane adhesive layer / unstretched polypropylene resin layer (thickness 40 μm) was prepared.
After filling the contents of the lid body prepared above into the same gas barrier container body as in Example 1, the atmosphere was replaced with nitrogen, heat sealed at the flange portion, the container was sealed, placed in the retort kettle, and the temperature, 125 Retort treatment (heat sterilization treatment) was performed under retort treatment conditions consisting of ° C., pressure, 2.1 kgf / cm ² , time, and 60 minutes, and a retorted package product of Comparative Example 1 was produced.
As a result, after the retort treatment, oxygen entered from the outside of the container, and the food was oxidized by this oxygen, and the discoloration and components of the food were deteriorated.

(Comparative Example 2)
In the layer structure of the lid 10 of the sealed packaging container for boil and retort in Example 1 described above, all examples were used except that instead of the aluminum foil and biaxially stretched nylon film, a 15 μm thick MX nylon film was used. 1. Layer structure, biaxially stretched polyethylene terephthalate film layer (thickness 12 μm) / two-component curable polyurethane adhesive layer / MX nylon film (thickness 15 μm) / two-component curable polyurethane adhesive layer / oxygen An absorbent material layer (thickness 30 μm) / unstretched polypropylene resin layer (thickness 40 μm) was prepared.
After the lid 10 produced above was filled in the same gas barrier container body as in Example 1, after nitrogen substitution, heat sealed at the flange, sealed the container, placed in the retort kettle, temperature, A retort treatment (heat sterilization treatment) was performed under the retort treatment conditions consisting of 125 ° C., pressure, 2.1 kgf / cm ² , time, and 60 minutes, and a retorted package product of Comparative Example 3 was produced.
As a result, after the retort treatment, oxygen entered from the outside of the container, and the food was oxidized by this oxygen, and the discoloration and components of the food were deteriorated.

[Change in content oxidation concentration over time]
Using the sealed packaging container for boil and retort (full capacity 230 ml) of Example 1 and Comparative Example 1, 180 ml of water was filled as the contents 30, and after replacing with nitrogen, heat sealed with a lid.
After that, it is put in a retort kettle and subjected to retort treatment (heat sterilization treatment) under conditions of temperature, 125 ° C., pressure, 2.1 kgf / cm ² , time, 60 minutes to produce a retorted package product. did.
Subsequently, it preserve | saved at 23 degreeC and measured oxygen concentration (%) of the head space in a container with time with the zirconia-type oxygen concentration meter. The results are shown in Table 1 and FIG.
Note that the vertical axis of FIG. 5 shows the oxygen concentration in the head space in the container, and the horizontal axis shows a graph showing the elapsed time in FIG.

As a result of measuring the oxygen concentration (%) of the head space in the container over time, in the case of the package of Comparative Example 1, the oxygen concentration of the head space in the container increased over time immediately after the retort treatment. On the other hand, in the case of the packaging body of the example, it was confirmed that the increase in the oxygen concentration in the head space of the container was suppressed from 7 days after the retort treatment.
Moreover, it has confirmed that the oxygen concentration of an Example fell after 7th.

It is the laminated material which comprises the cover material which concerns on this invention. It is the laminated material which comprises the gas barrier property shaping | molding container which concerns on this invention. It is sectional drawing of the airtight container for boil retort which concerns on this invention. It is a figure which shows the structure of the lid | cover material of the packaging body which can be boiled and retorted, and the heat bonding part of a container of this invention, (a) is sectional drawing of the state which adhere | attached, (b) is sectional drawing of the state which peeled the lid . It is a graph which shows the measurement result of the time-dependent change of the oxygen concentration of the head space in the packaging container which can be boiled and retorted of this invention.

Explanation of symbols

2 Heat resistant base film (outer layer)
3 Adhesive layer 4 Gas barrier layer (intermediate layer)
5 Adhesive Layer 6 Thermoplastic Resin Layer Containing Oxygen Absorbing Material (Intermediate Layer)
7 Print layer 8 Inner layer 10 made of thermoplastic resin layer 10 Lid 12 Thermoplastic resin (outer layer)
13, 15 Adhesive layer 14 Gas barrier thermoplastic resin (intermediate layer)
16 Thermoplastic resin layer (inner layer)
18 Easy-opening biothermoplastic resin layer 20 Gas barrier molding container 22 Knob piece 24 Flange part 26 Half cut part 28 Seal part 30 Contents 100 Container for sealed packaging for boil and retort

Claims (2)

A gas-barrier molded container, and a sealed container for boil and retort made of heat-sealed lid material containing the contents therein,
The gas-barrier molded container has a configuration in which an outer layer made of a thermoplastic resin, a gas barrier intermediate layer made of a gas-barrier thermoplastic resin, and an inner layer made of a thermoplastic resin layer are sequentially laminated from the outside,
The outer layer is made of polypropylene resin,
The gas barrier intermediate layer is an ethylene-vinyl alcohol copolymer, a nylon resin layer, an ethylene-vinyl alcohol copolymer layer, and a nylon resin layer, a nylon resin layer, an MXD nylon resin layer, and a nylon resin layer. A coextruded resin layer consisting of or MXD nylon resin layer,
The lid surface of the inner layer is composed of an easily openable thermoplastic resin layer,
The gas barrier molded container is a deep drawn container formed by vacuum / pressure forming,
The lid material is, from the outside, a heat resistant outer layer made of a heat resistant base film, and
A pinhole- resistant intermediate layer for imparting pinhole resistance ;
A gas barrier intermediate layer comprising an aluminum foil or an aluminum deposited layer ;
An oxygen-absorbing intermediate layer comprising a thermoplastic resin layer containing iron powder,
A laminate having a heat-sealable inner layer made of a thermoplastic resin layer,
The oxygen-absorbing intermediate layer is located closer to the contents than the pinhole-resistant intermediate layer and the gas barrier intermediate layer,
The heat-sealable inner layer of the lid material is made of polypropylene resin, high-density polyethylene resin, medium-density polyethylene resin, or linear low-density polyethylene resin,
Houses the 78% of the water volume of the shaped containers to said molded container, replacing the atmosphere by nitrogen, after retort sterilization in a sealed container state where the lid member is thermally sealed,
A sealed container for boil and retort , wherein the oxygen concentration (%) of the head space in the sealed container measured with a zirconia oximeter is 5% or less even when stored at 23 ° C for 3 months . Boiling sterilization treatment in hot water sealed container above SL is 70 to 100 ° C., or sealing boiling or retorting of claim 1, characterized in that withstand retort sterilization treatment at 100 to 135 ° C. container .