JP3166817B2 - Deoxidizing multilayer structure and package comprising the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deoxidizable multilayer structure capable of being molded with a resin and a package comprising the same.
More particularly, the present invention relates to a deoxygenated multilayered structure having excellent oxygen absorption performance and gas barrier properties, and which can be easily formed into a packaging container for foods, medicines and the like.

[0002]

2. Description of the Related Art Conventionally, as a technique for removing oxygen in a package of a preservation object such as food and medicine, and preventing oxidative deterioration of the preservation object, discoloration, deterioration due to mold and aerobic bacteria propagation, insect damage, and the like. In addition, a method of accommodating an oxygen absorber together with an object to be preserved in a gas barrier bag is widely used. This method usually involves
An oxygen absorber (hereinafter sometimes simply referred to as a small bag) in a small bag in which a powder or granular oxygen absorbing composition is stored in a small bag having air permeability is used. However, if the oxygen scavenger contained in the small bag is mixed in the object to be preserved, it may be erroneously cooked or eaten together with the object to be preserved, and also gives the user a feeling of foreign matter or resistance. . Furthermore, there is a possibility that the bag may be erroneously handled, the pouch may be broken, and the spilled oxygen scavenger composition may contaminate non-preserved materials. For this reason, in recent years, as a deoxygenating packaging technique without the above-mentioned problems, it is conceivable to configure a packaging container with a packaging material having deoxygenation performance, and a packaging container having a deoxygenation function in the container itself has been developed. ing.

As such an example, for example, Japanese Patent Publication No. Sho 62
-1824, JP-A-57-146661,
As disclosed in JP-A-4-45152, JP-A-4-90848 and the like, there are films and sheets having a multilayer structure including a layer in which an oxygen scavenger composition is dispersed in a resin. Furthermore, Japanese Patent Publication No. 4-60826 discloses that
A packaging container containing a commercially available oxygen absorber composition in a gas barrier thermoplastic resin is disclosed. In addition, 4-6
No. 2858 discloses a container containing a material that exhibits an oxygen-scavenging function for the first time due to high temperature and high steam pressure during retort treatment. Japanese Patent Publication Nos. Hei 4-60826 and Hei 4-62858 disclose a technique for preventing the oxygen barrier property of a gas barrier resin from being reduced during retort treatment and preventing oxygen from leaking from the outside of a container. Is disclosed.

[0004]

However, the conventional example in which the packaging container itself is provided with the oxygen absorbing performance itself has a higher oxygen absorbing performance than the conventional example in which the oxygen-absorbing agent in the small bag is stored in the package together with the object to be preserved. And there is a practical problem that oxygen present in the package cannot be efficiently removed in a short period of time. In particular, in a layer in which the oxygen absorber composition of the multilayer structure is dispersed in a resin, simply kneading the oxygen absorber composition of the oxygen absorber in a small bag into the resin,
Not only is it extremely difficult for the resin to intervene between the components of the oxygen scavenger composition dispersed in the resin and direct contact between the components is extremely difficult, but oxygen, water, etc. are also dispersed through the interposed resin molecules. The oxygen scavenger component must be reached. this is,
This becomes an extremely large inhibitory factor in the progress of the oxygen absorption reaction, and causes a problem that a sufficient oxygen absorption reaction rate cannot be obtained.
In order to solve such a problem, it is conceivable to increase the blending amount of the oxygen scavenger composition with respect to the resin, but this has many problems in resin molding.

If the oxygen scavenger composition to be dispersed in the resin contains water, the resin foams during the production of the multilayer structure and the thermoforming process of the multilayer structure into a packaging container. There is a problem in the resin molding process that unevenness occurs on the surface. Further, there is a problem that if a member made of an appropriate resin according to the oxygen scavenger composition to be compounded does not constitute a multilayer structure, there will be a problem during molding.

The present invention has been made to solve the above-mentioned problems, and provides a multilayer structure having a function of positively and efficiently absorbing oxygen, similar to a conventional oxygen absorber contained in a small bag. The purpose is to: Furthermore, in addition to the above, it is an object of the present invention to provide a multilayer structure excellent in resin moldability when manufacturing the multilayer structure and forming it into a packaging container formed therefrom.

[0007]

Means for Solving the Problems The present inventors, as a form of the oxygen-absorbing composition to be mixed with the resin, use all the components of the oxygen-absorbing composition which causes a deoxidation reaction when supplied with water. By containing it in the particles, the oxygen absorption reaction proceeded without hindrance and succeeded in obtaining a practical oxygen absorption rate. In addition, since the oxygen scavenger to be added to the resin is substantially free of moisture as described above, it is possible to solve the problem of resin moldability such as foaming during the production of the multilayer structure. In addition, it has been found that oxygen absorption does not occur until water is added, so that storage and handling can be excellent. Furthermore, they have found that the moldability under special thermoforming conditions can be improved by controlling the softening state of the resin, and have solved the above-mentioned problems of the prior art.

That is, a deoxidizing multilayer structure of the present invention comprises a first layer having a gas barrier property, a second layer having a deoxidizing property laminated on the first layer, and a second layer having a deoxidizing property. Wherein the first layer has an oxygen permeability of 100 cc / m ² · da.
y · atm (23 ° C., 100% RH), and the second layer has an oxygen permeability coefficient of 200 cc · 0.1 m
It is composed of a resin layer obtained by granulating and dispersing an oxygen scavenger composition that causes a deoxygenation reaction by supplying water to a resin having m / m ² · day · atm (23 ° C., 100% RH) or more. ,
The third layer has an oxygen permeability of 100 cc / m ² · day
-It is characterized by comprising a resin layer having atm (23 ° C, 100% RH) or more. Further, the oxygen-absorbing multilayer structure of the present invention is characterized in that in the oxygen-absorbing multilayer structure described above, the granular oxygen absorber composition has a water content of 0.2% by weight or less.

In the oxygen-desorbing multilayer structure of the present invention, the second layer contains a particulate oxygen-absorbing composition which causes a deoxygenation reaction when supplied with water, and transmits through the third layer. This layer absorbs incoming oxygen by receiving moisture. The resin constituting the second layer itself has oxygen permeability (oxygen permeability coefficient: 200 cc · 0.1 mm / m ² · day · atm (23 ° C.) in order to allow oxygen to efficiently reach the oxygen scavenger composition. , 100% RH)
Above).

Further, the first layer is an outermost layer when the multilayer structure of the present invention is formed into a package such as a container or a bag, and this layer prevents entry of oxygen from the outside. Performance is required. In addition, the third layer inside the package needs to have a capability of preventing the second layer from directly contacting the object to be preserved and of performing a rapid and efficient oxygen permeation.

For this reason, the first layer has as small an oxygen permeability as possible (oxygen permeability: 100 cc / m ² · day · atm).
(23 ° C., less than 100% RH), and the third layer has as high an oxygen permeability as possible (oxygen permeability; 10%).
0 cc / m ² · day · atm (23 ° C, 100% RH) or more). Note that the first layer and the third layer are not limited to a single layer, and may be, for example, a multilayer including an adhesive layer and the like. Also, when further providing an inner bag inside the package, or when further wrapping the outside of the package with a film or case,
The oxygen permeability of the first and third layers needs to be determined in consideration of these.

The multilayer structure of the present invention having the above-mentioned structure has a sufficient oxygen absorbing function and does not require any special treatment such as high-temperature treatment, as in the case of using the conventional pouch containing the oxygen scavenger composition. The function can be exhibited. Of course, there is no problem even if heat preservation, retort treatment, high-temperature filling (hot back) of the preservation material, and the like are performed after the preservation material is accommodated in the package formed from the multilayer structure. If the environmental temperature rises in this manner, the oxygen permeability of the third layer and the second layer is improved, and the reaction rate of oxygen absorption is also increased, so that more rapid oxygen absorption is performed.

Hereinafter, the multilayer structure of the present invention will be described in detail. The first layer is an outermost layer when a multilayer structure is formed into a package such as a container or a bag, and this layer needs to have a function of preventing oxygen from entering from the outside. The first layer is composed of one or more layers, and has an oxygen permeability of 100 cc / m ² · regardless of the thickness of each layer and the presence or absence of an adhesive or the like.
It must be less than day · atm (23 ° C., 100% RH), and more preferably its oxygen permeability is 50 cc / m ² · da
It is desirable that the temperature be equal to or less than y · atm (23 ° C., 100% RH).
It is preferable that the oxygen permeability of the first layer be as small as possible within the range permitted by the processing steps, costs, and the like. By doing so, when a package is manufactured using the multilayer structure according to the present invention, the amount of oxygen that enters from the outside of the package can be reduced, and the amount of the oxygen scavenger composition used can be reduced. Can be reduced. Further, the preservability of the package can be further improved.

Examples of the resin constituting the first layer include polyolefins such as polyethylene and polypropylene, modified products thereof, polyesters such as polyethylene terephthalate, polyamides such as nylon 6, nylon 66 and MX nylon, and ethylene-vinyl alcohol. Copolymer,
Synthetic resins such as polyvinyl chloride and polyvinylidene chloride are preferably used. The first layer may be a single layer or a multilayer including a combination of the above-described resin layers. Also,
Stretched material may be used.

The first layer may contain additives such as a filler, a coloring agent, an antistatic agent and a stabilizer.
In particular, the incorporation of a coloring agent such as a dye or a pigment into the resin constituting the first layer or the third layer results in hiding the second layer and adjusting the appearance of the package, thereby improving the appearance of the package. It is important in giving the commercial value to products. The first layer can be formed by co-extrusion, lamination, heat shrink wrap, wrap wrap, outer bag wrap, or the like. In the case of co-extrusion, the first
May be co-extruded together with the second layer, and if necessary, the first layer and the second layer may be bonded via an adhesive layer.

In the resin constituting the second layer, a so-called water-dependent type oxygen-absorbing composition, which undergoes a deoxidation reaction when supplied with water, is dispersed in a granular form. As the oxygen scavenger composition dispersed in the resin of the second layer, a granular substance is selected as a reducing substance serving as a main agent of a deoxygenation reaction, and the surface of the granular main agent is deoxygenated other than the main agent such as a catalyst or an auxiliary. What coated the agent composition, or the thing which granulated after mixing all the oxygen scavenger compositions other than the reducing substance of the main agent is used suitably.

Examples of the oxygen scavenger composition to be added to the second layer include metal powders such as iron powder, aluminum powder and silicon powder, inorganic salts such as ferrous salt and dithionite, and ascorbin. It is preferable to use an acid or a salt thereof or a reducing agent such as catechol or glycerin as a main agent. This base material is used in the form of granules together with other components as an oxygen scavenger composition. Among them, in particular, those obtained by attaching a metal halide to the surface of a metal powder by a method disclosed in Japanese Patent No. 1088514, a metal powder and a metal halide,
If necessary, other additives granulated using a binder are preferably used.

The metal powder is preferably iron powder. The metal iron is not particularly limited in purity and the like as long as it can cause the above-described deoxygenation reaction and can be dispersed in a thermoplastic resin. The part may be already oxidized or may be an alloy with another metal. Preferable examples include iron powder typified by reduced iron powder, sprayed iron powder, electrolytic iron powder, etc., iron powder scattered during the manufacture of cast iron (dalai powder), cast iron, pulverized products of various iron products such as steel, and the like. And fine particles or fibrous materials such as ground products. In the case of metallic iron in the form of particles, this is dispersed in a thermoplastic resin, and when forming the second layer, the thickness is reduced and the surface is smoothed. Should be smaller. Specifically, those having an average particle size of 200 μm or less are preferable, and those having an average particle size of 50 μm or less are particularly preferable. In the case of fibrous metallic iron, it is preferable that the diameter is as small as possible for the same reason.

The metal halide acts as a catalyst in the oxygen absorption reaction of metallic iron in the thermoplastic resin. Examples of the metal include alkali metals, alkaline earth metals, copper, zinc, aluminum, tin, and iron. , Cobalt and nickel.
Particularly, lithium, potassium, sodium, magnesium, calcium, barium, and iron are preferable. Examples of the halide include a chlorinated compound, a brominated compound and an iodized compound, and a chlorinated compound is particularly preferable.

The amount of the metal halide is preferably 0.1 to 20 parts by weight per 100 parts by weight of metallic iron. When substantially all of the metal halide adheres to the metallic iron and there is almost no free metal halide in the thermoplastic resin, and the metal halide works effectively, it is 0.1 to 5% by weight. Department is enough.

The metal halide is preferably added by a method that does not easily separate from metallic iron in the thermoplastic resin. For example, using a ball mill, a speed mill or the like, pulverizing and mixing, embedding metal halide fine particles in the concave portions of the metal iron surface, a method of attaching metal halide fine particles to the metal iron surface using a binder, A method of mixing and drying an aqueous metal halide solution and metallic iron and attaching metal halide fine particles to the metallic iron surface is particularly preferable.
In order to confirm that metallic iron and metal halide are not separated in the thermoplastic resin, analysis using an electron beam microanalyzer is preferable. If the constituent elements of iron and the metal halide are both present as electron beam images in the metal iron particles captured by the electron beam microanalyzer, the object has been achieved.

The initial oxygen content of the particulate oxygen-absorbing composition dispersed in the resin constituting the second layer is preferably 0.2% by weight or less, more preferably 0.1% by weight. It is desired that: The average particle diameter is preferably 5 to 200 μm.
More preferably, it is 0 μm.

As the resin constituting the second layer by dispersing the particulate oxygen absorbing composition, for example, polyolefins such as polyethylene, polypropylene, polybutadiene, polymethylpentene, and modified products thereof, or
A thermoplastic resin such as a graft polymer with a silicone resin, an ionomer, an elastomer, polycarbonate, and polyurethane is preferable, and a mixed resin thereof may be used.

The compounding ratio of the oxygen scavenger composition in the second layer is preferably from 2 to 93% by weight, and is preferably from 10 to 70% by weight.
More preferably, it is% by weight. If the blending ratio is too low, the oxygen absorption performance will decrease, and if it is too high, the processability will decrease. The thickness of the second layer is desirably 1000 μm or less, and more desirably, 500 μm or less.

In the second layer, in addition to the oxygen scavenger composition, if necessary, a coloring agent such as an organic dye, an inorganic dye or a pigment, a dispersant such as a silane or titanate, or a polyacrylic acid. It is also possible to add a water absorbing agent such as a system compound, a filler such as clay, mica, silica and starch, and a gas absorbent such as zeolite and activated carbon.

The third layer is a layer which becomes the inside of the package when the package is manufactured using the multilayer structure. This third
Is composed of one or more layers, and the oxygen permeability of each layer is 100 cc / m ² · da irrespective of the thickness of each layer and the presence or absence of an adhesive.
y · atm (23 ° C, 100% RH) or higher. More preferably, the oxygen permeability is 200 cc.
/ M ² · day · atm (23 ° C, 100% RH) or more is desired. That is, it is preferable that the oxygen permeability of the third layer be as large as possible within the range permitted by the processing steps, costs, and the like. By configuring the third layer in this manner, when the object to be preserved is stored in the package having the multilayer structure of the present invention, oxygen and moisture present inside the package are passed through the third layer. The second layer can be quickly reached, and oxygen can be efficiently and quickly absorbed by the second layer.

Examples of the resin constituting the third layer include polyolefins such as polyethylene, polypropylene, polybutadiene and polymethylpentene, and modified products thereof, graft polymers with silicone resins, polyesters such as polyethylene terephthalate, and nylons. 6, synthetic resins such as polyamides such as nylon 66, ionomers, and elastomers are preferably used.

The third layer may be a single layer or a multilayer formed by combining the above-mentioned resin layers. Further, a mixed resin layer obtained by mixing these resins may be used. Furthermore, microporous membranes formed with micropores in these resins,
It may be a non-woven fabric. In addition, since the third layer becomes the inner wall of the package formed by the multilayer structure according to the present invention,
It is necessary to reliably isolate the object to be stored and the second layer contained in the package, and to have high air permeability. For this purpose, the material constituting the third layer has an adhesive property capable of being coextruded with the material constituting the second layer, and the third layer is a single layer having a small thickness. desirable.

As the thickness of the third layer is smaller, the air permeability is improved, but the moldability, the concealing property, and the separability between the second layer and the object to be preserved are reduced. 100 μm
It is desired to be on the order. The third layer can be added with, for example, dyes and pigments for hiding and coloring, and various additives for improving heat sealing properties and the like. Further, additives such as a filler, an antistatic agent, and a stabilizer can be blended in the third layer.

The third layer can be formed by coextrusion, lamination, inner bag, or the like. In the case of co-extrusion, it may be extruded together with the second layer, and if necessary, the third layer and the second layer may be bonded via an adhesive layer.

When the multilayer structure according to the present invention is subjected to thermoforming to produce a package such as a tray or a cup,
Depending on the heating method of the molding machine, improvement of the molding cycle,
If the heating temperature at the time of molding is kept low for the purpose of maintaining the appearance, transparency, and other purposes, minute irregularities may occur in the third layer inside the package. This is because, in the second layer, a large amount of the oxygen-absorbing composition having high thermal conductivity is dispersed in the resin, so that the resin existing near the oxygen-absorbing composition is quickly heated, This is because unevenness is formed in the second layer due to a difference in the softening property of the resin within one layer, and the third layer, which has already been sufficiently softened, follows the unevenness of the second layer. In particular, the third layer is often made thinner than the first layer in order to make the air permeability good, and thus the influence of the unevenness is large, and the third layer is likely to become apparent.

In the present invention, this phenomenon can be prevented from occurring by softening the resin constituting the second layer faster than the resin constituting the third layer. For this purpose, the resin of the second layer is preferably a resin whose softening point is equal to or lower than the softening point of the resin constituting the third layer . For example, when the third layer and the first layer are mainly made of polypropylene, it is preferable to use an ethylene-propylene random copolymer for the second layer.

The multilayer package according to the present invention can be formed into a package once the multilayer structure according to the present invention is formed, or can be directly formed into a package composed of the multilayer structure. . In either case, a known method can be applied to the formation of the package, and various means used in conventional resin processing and container processing can be applied.

For example, the package can be directly formed by a known resin molding processing technique such as extrusion molding using a T die, a circular die, injection molding, direct blow, stretch blow and the like. Further, using the sheet, tube, and parison obtained by these methods, a package can be formed by vacuum forming, pressure forming, plug assist forming, overhang forming, blow molding, or the like. Furthermore, after the main part is formed, it can be combined with another molded product, or subjected to various laminations such as heat lamination, dry lamination, extrusion lamination and hot melt lamination, and lamination processing such as coating. Further, outer packaging or inner packaging using shrink packaging, shrink label packaging, a case, a bag, or the like can be applied.

Examples of the package formed by these methods include trays, cups, tubes, bottles, cases, bags, and the like. Further, it is also possible to adopt a form in which a sheet made of the multilayer structure according to the present invention is used as a top film in a gas barrier container such as a tray or a cup. In the usage form of the multilayer package, it is necessary to finally seal the package in order to prevent invasion of oxygen from the outside of the package. As the sealing method, closures, a top film, an outer package, and other conventional techniques can be applied.

[0036]

Next, an embodiment according to the present invention will be described with reference to the drawings. It should be noted that the present embodiment shows an embodiment of the present invention, and the present invention is not limited by these embodiments. [Example 1] 50% by weight of iron powder having a diameter of 35 µm was placed in a vacuum mixing dryer equipped with a heating jacket, and was heated at 130 ° C and 10 mmH.
g of calcium chloride: sodium chloride: water = 0.5: 100 parts by weight while heating and drying under reduced pressure.
A mixed aqueous solution mixed at a ratio of 0.5: 2.5 (parts by weight) is sprayed to obtain a granular oxygen absorber composition in which calcium chloride and sodium chloride are adhered to the iron powder surface. Next, 4
The polypropylene and the oxygen scavenger composition are kneaded with a 5 mmΦ co-rotating twin screw extruder in a weight ratio of polypropylene: oxygen scavenger composition = 2: 3, cooled by a net belt with a blower, and then passed through a pelletizer. To obtain pellets containing the oxygen scavenger composition.

Next, the first and fourth extruders, a feed block, a T-die, a cooling roll, and a sheet take-up machine are used to form a first-to-six-layered multi-layer sheet forming apparatus.
The extruder containing white pigment was used for the extruder, the pellets containing the oxygen scavenger composition were used for the second extruder,
Extruder with ethylene vinyl alcohol copolymer,
A maleic anhydride-modified polypropylene was used for the fourth extruder, and these were extruded from each extruder.
To obtain a multilayer structure as shown in FIG. This multilayer structure is composed of a third layer 3 made of white pigment-added polypropylene,
A second layer 2 laminated on the layer 3 and composed of the oxygen scavenger pellets; a layer 13 composed of maleic anhydride-modified polypropylene laminated on the second layer 2; A first layer 1 comprising a layer 14 composed of a vinyl alcohol copolymer, a layer 15 laminated on the layer 14 and composed of maleic anhydride-modified polypropylene, and a layer 16 laminated on the layer 15 and composed of a polypropylene added with white pigment. And In this embodiment, the thickness of the third layer is 100 μm, and the thickness of the second layer is 1 μm.
00 μm, the thickness of the layer 13 is 15 μm, and the thickness of the layer 14 is 2
0 μm, the thickness of the layer 15 is 15 μm, and the thickness of the layer 16 is 25
It was set to 0 μm.

Next, plug-assist molding was performed at about 180 ° C. using a vacuum forming machine with the third layer 3 of the multilayer structure inside, and the tray-shaped container shown in FIG.
0 mm x 30 mm depth, internal volume about 350 cc).

Next, 200 g of boiled pasta was placed in the tray-shaped container obtained in the present example, and nitrogen was replaced with a cup sealer equipped with a nitrogen blowing device so that the oxygen concentration in the tray-shaped container was about 5%. In this state, the top film 10 is heat-sealed as shown in FIG. 3 to seal the tray-shaped container. Although not particularly shown, the top film 10 has a layer made of polypropylene having a thickness of 50 μm, a layer laminated on this layer and made of maleic anhydride-modified polypropylene having a thickness of 5 μm, and A layer composed of an ethylene-vinyl alcohol copolymer having a thickness of 10 μm, a layer composed of maleic anhydride-modified polypropylene having a thickness of 5 μm laminated on this layer, and a film laminated and laminated on this layer. And a layer made of nylon having a thickness of 20 μm.

Next, the sealed tray-like container containing the boiled pasta was stored at room temperature, and the storage condition of the pasta was examined while measuring the oxygen concentration in the tray-like container over time by gas chromatography. Further, after storing the tray-shaped container for 30 days, a small hole was made in the top film 10 and heated in a microwave (500 W, manufactured by Mitsubishi Electric Corporation) for 5 minutes to examine the microwave resistance. Table 1 shows the results.

On the other hand, a sheet corresponding to the first layer 1 and a sheet corresponding to the third layer 3 are separately prepared by the above-described manufacturing method, and the two sheets are formed in the same tray shape as described above. Form into containers. Next, the oxygen permeability at 23 ° C. and 100% RH was measured for the obtained two tray-shaped containers. As a result, the oxygen permeability of the sheet corresponding to the first layer 1 is 10 cc / m ² · day · atm or less, and the oxygen permeability of the sheet corresponding to the third layer 3 is 90
It was 0 cc / m ² · day · atm or more.

[Comparative Example 1] Next, as Comparative Example 1, 50
A mixture 1 in which 100 parts by weight of iron powder having a weight% diameter of 35 μm and calcium chloride: sodium chloride = 1: 1 are mixed.
Parts by weight with a Henschel mixer to obtain an oxygen scavenger composition. Then, using the oxygen-absorbing composition in place of the oxygen-absorbing composition obtained in Example 1, in the same manner as in Example 1, producing oxygen-absorbing composition-containing pellets, sheet forming, and a tray-shaped container To obtain a tray-shaped container (Comparative product 1). Next, the tray-shaped container (comparative product 1) was filled with boiled pasta in the same manner as in Example 1, sealed, and subjected to the same storage stability test and microwave resistance test as in Example 1. Table 1 shows the results.

Comparative Example 2 Next, as Comparative Example 2, a sheet similar to the multilayer structure obtained in Example 1 was obtained except that the second layer 2 according to Example 1 was not provided. Next, in the same manner as in Example 1, sheet molding and molding of a tray-shaped container are performed to obtain a tray-shaped container (Comparative Product 2). Next, boiled pasta was accommodated in the tray-shaped container (comparative product 2) in the same manner as in Example 1, sealed, and subjected to the same storage stability test and microwave resistance test as in Example 1. Table 1 shows the results.
Shown in

Comparative Example 3 Next, as Comparative Example 3, Comparative Product 2 was used, in which boiled pasta similar to that of Example 1 and a small bag containing an oxygen scavenger composition (manufactured by Mitsubishi Gas Chemical, Ageless FX "), sealed in the same manner as in Example 1, and subjected to the same storage stability test and microwave resistance test as in Example 1. Table 1 shows the results.

[0045]

[Table 1]

From Table 1, it can be seen from Example 1 and Comparative Examples 1 to 3.
Shows that the oxygen concentration in the tray-shaped container at the start was almost the same, but after 7 days, the oxygen concentration in the container of Example 1 and Comparative Example 3 was reduced to 0.1% or less. This is because in Example 1, the oxygen scavenger composition, which is a component of the tray-shaped container, was able to efficiently absorb oxygen in the tray-shaped container. In Example 1 and Comparative Example 3, 3
It can also be seen that even after storage for 0 days, there was no generation of mold and good flavor was maintained. Example 1
Was confirmed to have the same oxygen absorption performance as Comparative Example 3 in which a pouch containing the oxygen scavenger composition was stored. Furthermore, Example 1 was also confirmed to be excellent in microwave resistance. On the other hand, in Comparative Examples 1 and 2, the oxygen concentration in the container after 7 days hardly changes. Comparative Example 1
In Nos. 2 and 3, it was confirmed that mold and deteriorating odor had occurred after 30 days. Here, Comparative Examples 1 and 2
Means that the oxygen concentration in the container after 30 days has dropped to 0.1 or less, because the generated mold consumed the oxygen. As described above, it has been proved that the tray-shaped container formed from the multilayer structure according to the present invention has excellent oxygen absorption performance and can block invasion of oxygen from outside the container. Furthermore, the multilayered structure according to the present invention can absorb practical oxygen without high-temperature treatment such as heat sterilization or retort treatment, and can be applied to various foods and medicines. In addition, it has excellent microwave resistance and can be used in a microwave oven.

[Second Embodiment] A second embodiment according to the present invention will be described with reference to the drawings. 100 parts by weight of iron powder having an average particle diameter of 20 μm or less, 1 part by weight of calcium chloride, 2 parts by weight of yellow iron oxide, 0.5 parts by weight of powdered activated carbon, and an average particle diameter of 1 part
After mixing 3 parts by weight of polypropylene pulverized to 0 μm or less with a Henschel mixer, with a rotary tableting machine,
Form into tablets 9 mm in diameter. Next, the tablet is pulverized with a speed mill and sieved to obtain a deoxidizer composition sized to 100 to 250 mesh. Then, 45mmΦ
And the above-described oxygen-absorbing composition are kneaded at a weight ratio of polypropylene: oxygen-absorbing composition = 1: 1. Next, the kneaded product is extruded from a strand die, cooled with a net belt with a blower, and then passed through a pelletizer to obtain pellets containing the oxygen scavenger composition.

Next, as shown in FIG. 4, a third layer (film) made of polyethylene was used in order from the inside using a blow molding apparatus comprising first and second extruders, a multilayer circular die and a blow mold. Wide-mouth bottle (40 mm in diameter) in which a second layer made of polyethylene (thickness: 200 μm) in which the oxygen scavenger composition is dispersed and a third layer made of polyethylene (thickness of the body: 450 μm) are laminated. , Body diameter 60mm, height 95mm, capacity about 180
ml).

Next, 100 g of diced bacon was put into the wide-mouth bottle, and a metal rug cap 10
The container sealed in 1 was stored at room temperature, and the oxygen concentration in the bottle was measured over time and the storage stability of bacon was examined. The measurement of the oxygen in the bottle over time was performed by gas chromatography.
Days, 30, and 190 days. Table 2 shows the results.

Example 3 A wide-mouth bottle similar to the wide-mouth bottle obtained in Example 2 was provided with a cylindrical body having a diameter of 65 mm and a height of 80 mm, and a laminate of polyolefin and ethylene-vinyl acetate copolymer. A barrier shrink film having a structure ("BDF2001" manufactured by Cryovac) is put on and shrunk and adhered by hot air to obtain a wide-mouth bottle shown in FIG. That is, in this embodiment, the first layer is composed of a 450 μm-thick polyethylene film and a barrier shrink film. Next, inside the wide-mouth bottle coated with the barrier shrink film, a diced bacon was sealed in the same manner as in Example 2, and the same investigation as in Example 2 was performed. Table 2 shows the results.

Comparative Example 4 Using a single extruder of the same blow molding apparatus as in Example 2, a wide-mouthed bottle of the same type made of polyethylene alone (body thickness: 700 μm) was formed. Next, a square-cut bacon was sealed in the wide-mouthed bottle in the same manner as in Example 2, and the same investigation as in Example 2 was conducted.
Table 2 shows the results.

Comparative Example 5 100 parts by weight of iron powder having an average particle diameter of 20 μm or less, 1 part by weight of calcium chloride, and 2 parts of yellow iron oxide
Parts by weight, 0.5 parts by weight of powdered activated carbon, and 3 parts by weight of polypropylene pulverized to 10 μm or less are mixed with a Henschel mixer to obtain an oxygen scavenger composition. Next, Example 2
A wide-mouth bottle is formed in the same manner as in Example 2 except that the oxygen-absorbing composition used in Example 2 is used instead of the oxygen-oxidizing composition used in Example 2. Then, the wide-mouthed bottle was sealed with diced bacon as in Example 2, and the same investigation as in Example 2 was conducted. Table 2 shows the results.

The second layer in the wide-mouth bottle formed in Examples 2 and 3 (a layer made of polyethylene having a thickness of 450 μm in Example 2; a polyethylene layer having a thickness of 450 μm in Example 3) Regarding the oxygen permeability of the barrier shrink film layer and the third layer (in both examples, a layer made of polyethylene having a thickness of 50 μm), the layer made of polyethylene is made of T using the same raw material as in the example. A sheet having the same thickness was separately formed using a sheet forming apparatus having a die, and the oxygen permeability of the sheet was measured. The barrier shrink film was measured before heat shrinkage. Table 2 shows the results.

From Table 2, it can be seen that in Example 3, since the barrier shrink film was coated on the outside of the wide-mouth bottle, the oxygen permeability of the first layer showed an extremely low value of 20 cc / m ² · day · atm or less. You can see that. Also, in Examples 2 and 3, the oxygen concentration in the wide-mouth bottle was 0.1% after 7 days of storage.
It can be seen that it has decreased to 1% or less. This is because the oxygen scavenger composition, which is a component of the wide-mouth bottle, was able to efficiently absorb oxygen in the wide-mouth bottle. Example 2
In Example 3, even after storage for 30 days, the oxygen concentration in the wide-mouth bottle maintained 0.1% or less, and it was confirmed that the properties of the bacon were good. In Example 3, even after storage for 190 days, the oxygen concentration in the bottle and the properties of the bacon were retained. On the other hand, in Comparative Examples 4 and 5, no decrease was observed in the oxygen concentration in the bottle after 7 days of storage, and abnormalities were observed in the properties of the bacon after 30 days. After storage for 190 days, it was confirmed that both Comparative Examples 4 and 5 had deteriorated.

[0055]

[Table 2]

Example 4 An oxygen-absorbing composition produced in the same manner as in Example 1 and an ethylene-propylene random copolymer (Vicat softening temperature; 119 ° C.) were mixed with an oxygen-absorbing composition: ethylene-propylene. The random copolymer is kneaded at a weight ratio of 3: 2 to obtain an oxygen-absorbing composition pellet. Next, the oxygen-absorbing composition used in Example 1 was replaced with the oxygen-absorbing composition-blended pellets manufactured in this example, and the white pigment-added polypropylene used in Example 1 was replaced with ethylene- Using a propylene block copolymer (Vicat softening temperature: 144 ° C.), a multilayer structure having the same thickness as in Example 1 is formed in the same manner as in Example 1.

Next, both the multilayer structure and the multilayer structure obtained in Example 1 were heated by using two types of molding machines shown in Table 3 while changing the heating temperature as shown in Table 3 to form a tray-shaped container. (Vertical 150
mm x width 100mm x depth 30mm, internal volume about 350cc)
Molding was performed so that the third layer was on the inside, and the molding state was investigated. Table 3 shows the results.

[0058]

[Table 3]

From Table 3, it can be seen that the tray-shaped container according to Example 4 has no irregularities on the inner surface of the tray-shaped container and has good moldability even when the heating temperature during molding is as low as 165 ° C. It turns out that it was obtained. This is an effect obtained because the softening temperature of the resin forming the second layer of the multilayer structure forming the tray-shaped container according to Example 4 was lower than the softening temperature of the resin forming the third layer. is there.

[0060]

The packaging container formed from the oxygen-desorbing multilayer structure of the present invention has an excellent oxygen absorption performance as compared with a container containing a conventional oxygen-absorbing agent, and can block invading oxygen from outside the container. And the oxygen in a container can be absorbed quickly. In particular, this packaging container according to the present invention can practically absorb oxygen without high-temperature treatment such as heat sterilization and retort treatment as in the case of conventional packaging using a small bag-shaped oxygen absorber, and can be used for a wide range of foods, medicines, etc. It can be applied to Of course, it is also possible to handle at a high temperature, such as a high-temperature treatment after filling the object to be preserved or a hot pack of the object to be preserved. In addition, the deoxidizing multilayer structure of the present invention does not have a foreign-body sensation as in the case of using a pouch-shaped deoxygenating agent, and is also excellent in microwave resistance, etc. It is a multilayer structure. The article preservation by the deoxidizing multilayer structure of the present invention can be effectively used as a safe preservation method for preserving not only food and medicine but also products in a wide range of fields.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a multilayer structure according to the present invention.

FIG. 2 is a cross-sectional view of a container having a multilayer structure according to the present invention.

FIG. 3 is a cross-sectional view showing a state in which an object to be preserved is accommodated in a container according to the present invention, and this is sealed.

FIG. 4 is a cross-sectional view of a wide-mouth bottle made of a multilayer structure according to the present invention.

FIG. 5 is a cross-sectional view of another wide-mouth bottle made of a multilayer structure according to the present invention.

FIG. 6 is a cross-sectional view showing a state in which a lid made of a multilayer structure according to the present invention is placed on a container.

FIG. 7 is a cross-sectional view of another wide-mouth bottle made of a multilayer structure according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first layer 2 second layer 3 third layer 13 layer composed of maleic anhydride-modified polypropylene 14 layer composed of ethylene vinyl alcohol copolymer 15 layer composed of maleic anhydride-modified polypropylene 16 composed of polypropylene with white pigment layer

Claims (7)

(57) [Claims] A first layer having a gas barrier property, a second layer having a deoxidizing property laminated on the first layer, and a second layer having a gas permeability laminated on the second layer. A laminate comprising: a first layer having an oxygen permeability of 100;
cc / m ² · day · atm (23 ° C., 100% RH), wherein the second layer has an oxygen permeability coefficient of 200
Resin obtained by granulating and dispersing an oxygen scavenger composition that generates a deoxygenation reaction by supplying water to a resin having a cc · 0.1 mm / m ² · day · atm (23 ° C., 100% RH) or more And the third layer has an oxygen permeability of 100 cc / m ^2.
A deoxidizing multilayer structure comprising a resin layer having a day • atm (23 ° C., 100% RH) or higher. 2. The oxygen-absorbing multilayer structure according to claim 1, wherein the oxygen-absorbing composition dispersed in the second layer in a granular form has a water content of 0.2% by weight or less. 3. The deoxidizing multilayer structure according to claim 1, wherein the resin of the second layer is a resin whose softening point is equal to or lower than the softening point of the resin constituting the third layer. 4. The oxygen scavenger composition selects a granular substance as a reducing substance which is a main agent of a deoxidation reaction, and the surface of the granular main agent is selected .
The deoxidizing multilayer structure according to claim 1, wherein a catalyst is coated on the multilayer structure. (5) Oxygen scavenger composition halogenates metal powder
Metal attached to the surface, or metal powder and halogen
Wherein the metal oxide is granulated using a binder.
2. The deoxidized multilayer structure according to 1. 6. An oxygen scavenger composition comprising: (1) a ball mill
Ku is produced by a method of embedding the metal halide particles in the recess of the grinding and mixing iron metal surface using speed mill
Which was, as those produced by the method of attaching the metal halide particles to metallic iron surface with (2) a binder,
Or, (3) mixing dry the metal halide solution and metallic iron as those produced by the method of attaching the metal halide particles to metallic iron surface, deoxidizing multilayered structure according to claim 1, wherein a. 7. A first layer having a gas barrier property, a second layer having a deoxidizing property laminated on the first layer, and a second layer having a gas permeability laminated on the second layer. A laminate comprising: a first layer having an oxygen permeability of 100;
cc / m ² · day · atm (23 ° C., 100% RH), wherein the second layer has an oxygen permeability coefficient of 200
Resin obtained by granulating and dispersing an oxygen scavenger composition that generates a deoxygenation reaction by supplying water to a resin having a cc · 0.1 mm / m ² · day · atm (23 ° C., 100% RH) or more And the third layer has an oxygen permeability of 100 cc / m ^2.
A package comprising a multilayer structure composed of a resin layer having a day · atm (23 ° C., 100% RH) or higher, wherein the first layer is viewed from the outside and the third layer is viewed from the inside.