JP3362756B2 - Oxygen-absorbing resin composition and oxygen-absorbing laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oxygen-absorbing resin composition having improved storage stability and excellent thermoformability, and an oxygen-absorbing laminate comprising the same. The present invention also provides a poly-
The present invention relates to an oxygen-absorbing laminate in which 4-methylpentene-1 (hereinafter referred to as polymethylpentene) is used as a breathable isolation layer. The packaging container comprising the oxygen-absorbing laminate of the present invention is excellent in oxygen absorption performance and gas barrier property, and is suitable for storing foods, chemicals and the like.

[0002]

2. Description of the Related Art Conventionally, a resin layer in which a deoxidizer composition is dispersed in a resin has been used for a member such as a film, a sheet or a container.
The technology that gives the packaging material itself oxygen absorption capability is
2-1824, JP-A-57-146651, JP-A-4-45152, and JP-A-4-90848. However, these conventional techniques have a serious problem that the oxygen absorption rate is slow, the oxygen absorption capacity is low, and a practical deoxidization function cannot be obtained. As a result of various studies to raise the deoxidizing function to a practical level, the present inventors have used a resin layer containing a deoxidizing agent composition containing a metallic iron base compound as a practical material, which is far superior to that of the prior art. The development of an oxygen-absorbing laminate capable of exerting a deoxidizing function has been developed, and it has already been proposed in Japanese Patent Application No. 7-158159.

However, according to the research conducted by the present inventors, it has been found that as the oxygen absorption performance of the oxygen-absorbing laminate is improved and the performance thereof is improved, handling problems will occur. did. In the case of an oxygen-absorbing resin composition containing a deoxidizer composition mainly composed of metallic iron, which has the best oxygen-absorbing ability, in one case, a laminate made of this oxygen-absorbing resin composition is molded next. During the storage period until processing,
In addition, during the storage period until the product in which this laminate is molded into a film, sheet, bottle, etc. is actually used,
There was a problem that oxygen in the environment was gradually absorbed and the oxygen absorption capacity decreased, which was not a problem in the past simply by simply packaging. Another is that when a sheet of an oxygen-absorbing laminate is thermoformed into a container or the like, if the storage period after sheet forming is long, the sheet foams during thermoforming such as vacuum forming and pressure forming, It was the occurrence of pockmarks on the surface of the sheet. The cause of such a problem is that the oxygen absorption capacity of this laminate was improved, resulting in higher oxygen absorption activity, and this made it very easy to take in the water necessary for the oxygen absorption reaction. Conceivable.

For example, in the case of ethylene-vinyl alcohol copolymers having high hygroscopicity and various nylon pellets and multilayer sheets, moisture due to moisture will hinder the molding process. Therefore, moisture-proof packaging has been conventionally used as a measure against moisture absorption of resins. However, moisture absorption does not become a particular problem at the product stage when it is formed into a film, container, etc., and it can be distributed by extremely simple packaging such as packing in a plastic bag inside a bag. Become. On the other hand, in the oxygen-absorbing resin layer having an improved oxygen absorption performance by blending the oxygen absorber composition of the metallic iron base agent, water is originally an essential component for the oxygen absorption reaction due to the oxidation of iron, and the reaction In order to obtain the required water content, the oxygen absorbing property of the oxygen absorber composition is not large enough to obtain the desired oxygen absorbing performance. Therefore, the hygroscopic property of the oxygen absorbing resin layer is It is so large that it cannot be prevented with simple moisture-proof packaging. Therefore, the oxygen-absorbing laminate and its molded article made of the oxygen-absorbing resin layer, the more the oxygen-absorbing performance is improved, the more the oxygen-absorbing ability works even with a slight moisture absorption, and the oxygen-absorbing ability is reduced during storage. In order to invite them, it is necessary to take special moisture prevention measures into consideration.

Even if a desiccant such as silica gel or zeolite is used as a moisture-proof measure, the hygroscopicity is large,
Moreover, in the above oxygen-absorbing laminate in which the water once absorbed by the oxygen scavenger composition is irreversible and is not easily dehumidified by the desiccant, a large amount of the desiccant is required, and the effect is not always sufficient. Can not be solved. It is also conceivable to store it in a metal can or a metal foil laminated heat-sealing bag that has a complete gas barrier property, but there are many problems such as workability, strength, and packaging equipment when packaging a roll of film or sheet of several hundred kg. Further, when it comes to packaging a molded article such as a container, since the shape is complicated, it cannot be packaged in a bulky and efficient manner, and workability, cost and the like become problems.

Polymethylpentene, which is excellent in oxygen permeability, has been conventionally proposed for a breathable film of an oxygen-absorbing laminate comprising an oxygen-absorbing resin layer. However, there was a problem with the adhesiveness between the resin layer of polymethylpentene and the oxygen-absorbing resin layer, and it could not be put to practical use easily.

[0007]

SUMMARY OF THE INVENTION The first object of the present invention is to solve the above problems relating to the preservability of an oxygen-absorbing laminate which is newly generated by improving the oxygen-absorbing ability, and to provide long-term preservation with simple moisture-proof packaging. It is an object of the present invention to provide an oxygen-absorbing laminate that is made possible and has no deterioration in oxygen absorption performance during storage, and that has no problem in thermoforming processing after storage and has improved storage stability. A second object of the present invention is to solve the above problems in forming a breathable isolation layer made of polymethylpentene in an oxygen-absorbing laminate, and to improve the oxygen permeability of polymethylpentene in the breathable isolation layer. An object of the present invention is to provide an oxygen-absorbing laminate having excellent adhesive workability while making use of excellent characteristics.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result, as a result, an alkali was added to a thermoplastic resin containing a deoxidizer composition that obtains water to cause an oxygen absorption reaction. By adding an earth metal oxide, it was found that the first problem can be solved, and by using a resin layer made of a mixture of polymethylpentene and polyolefin as a gas permeable isolation layer, the second The present invention has been completed by finding that the problems can be solved.

That is, the oxygen-absorbing resin composition of the present invention comprises a thermoplastic resin in which a deoxidizer composition that obtains water to cause an oxygen-absorbing reaction and an alkaline earth metal oxide are dispersed. Is a resin composition. The oxygen absorbing composition in the oxygen absorbing resin composition of the present invention is preferably made of metal iron and metal halide, rather more preferably it is made of iron powder and metal halide,
Further, iron powder to which a metal halide is attached is most preferable. Further, in the oxygen-absorbing resin composition ,
The metallic iron content is 2 to 93% by weight, preferably 10
Is about 70% by weight, and the content of the metal halide is preferably 0.1 to 20 parts by weight per 100 parts by weight of metallic iron,
The alkaline earth metal oxide content is preferably 0.1 to 5% by weight. The particle size of the iron powder is 200 μm in average particle size.
m or less, more preferably 1 to 50 μm, and the particle size of the alkaline earth metal oxide is 1 to 20 as an average particle size.
0 μm is preferable, and 1 to 50 μm is more preferable.

Further, the oxygen-absorbing laminate of the present invention is a laminate having a breathable isolation layer on at least one surface of the intermediate layer made of the oxygen-absorbing resin composition. Further, the oxygen-absorbing laminate of the present invention is a laminate having an air-permeable isolation layer on one side of the intermediate layer made of the oxygen-absorbing resin composition and a gas barrier isolation layer on the other side. The oxygen-absorbing laminate of the present invention is a laminate having an air-permeable isolation layer on both sides of an intermediate layer made of the oxygen-absorbing resin composition.

Further, in the oxygen-absorbing laminate of the present invention, the proportion of poly-4-methylpentene-1 is 5 in the resin layer in which the oxygen scavenger composition is dispersed in the resin made of polyolefin.
It is an oxygen-absorbing laminate formed by laminating a mixed resin with a polyolefin of 0% by weight or less, preferably 10 to 40% by weight. Further, in the oxygen-absorbing laminate of the present invention, the polyolefin is preferably polyethylene, polypropylene or a copolymer thereof.

[0012]

In general, the oxygen absorbing ability of the metallic iron-based deoxidizer decreases when it contains an alkaline earth metal hydroxide.
The oxygen absorption reaction by metallic iron is described by the following equation. ^{Fe → Fe 2+ + 2e - (} 1) H 2 O + 1/2 O 2 + 2e - → 2OH - (2) Fe + H 2 O + 1/2 O 2 + 2e - → Fe 2+ + 2OH - (3) That is, by oxidation of iron Oxygen absorption largely depends on the pH of the reaction environment, and when the pH is high and alkaline, the electron transfer reactions of the formulas (1) and (2) are obstructed and the oxygen absorption reaction becomes difficult to proceed. On the other hand, it is known that alkaline earth metal oxides easily react with water to form a strongly alkaline alkaline earth metal hydroxide. Therefore, the alkaline earth metal oxide is used as a deoxidizer for the metallic iron base agent. When coexisting, the water required for the oxygen absorption reaction is consumed by the hydroxylation of the alkaline earth metal oxide, making it difficult for the oxygen absorption reaction to occur, and the alkaline earth metal hydroxide produced makes it alkaline. To inactivate it.

However, in the oxygen-absorbing resin composition of the present invention, even if the oxygen absorber composition and the alkaline earth metal oxide coexist in the resin, the oxygen absorber composition absorbs moisture during storage. Is suppressed to prevent the oxygen absorption performance from deactivating, and the oxygen absorption reaction is not hindered at all when used. This means that the oxygen absorber composition and the alkaline earth metal oxide are sufficiently dispersed in the resin, and the alkaline earth metal oxide is substantially separated from the oxygen absorber composition by the resin. However, even if a hydroxide is formed, the alkali ions are unlikely to migrate to the oxygen absorber composition, so that the oxygen absorber composition itself does not become alkaline. Furthermore, the alkaline earth metal oxide of the oxygen-absorbing resin composition is not only water due to moisture absorption, but oxygen is removed in order to remove a slight amount of attached water or crystallization water present in the thermoplastic resin or the oxygen absorber composition. In the mixing, kneading and thermoforming of the absorbent resin composition by an extruder, and the subsequent thermoforming of the oxygen-absorbing laminate, a remarkable effect is obtained in preventing troubles such as foaming.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The oxygen scavenger composition to be blended with the oxygen-absorbing resin composition of the present invention is one which can obtain water to cause an oxygen-absorption reaction and is dispersed in a thermoplastic resin. If possible, it can be used without limitation, but a deoxidizer composition containing metallic iron as a main component of the oxygen absorption reaction is preferable, and one containing metallic iron and a metal halide is particularly preferable. As the main ingredient, metallic iron, as long as it is capable of causing an oxygen absorption reaction, it can be used without any particular limitation on the purity and the like.For example, even if a part of the surface is already oxidized, it contains another metal. May be. Further, the metallic iron is preferably granular or fibrous, for example,
Iron powder such as reduced iron powder, atomized iron powder, electrolytic iron powder, pulverized products of various irons such as Dalai powder, cast iron, steel materials, and ground products are used.
The iron powder is preferably fine so that the layer thickness of the oxygen absorbing resin can be made thin, and the average particle size is preferably 200 μm or less,
Particularly, 1 to 50 μm is preferable.

The metal halide catalytically acts on the oxygen absorption reaction of the main agent. As a metal halide,
Examples thereof include halides of metals selected from the group consisting of alkali metals, alkaline earth metals, copper, zinc, aluminum, tin, iron, cobalt and nickel, including lithium, potassium, sodium, magnesium, calcium or barium halides. preferable. Examples of halides of the above metals include chlorides, bromides and iodides, with chlorides being preferred. The amount of the metal halide compounded is selected in the range of 0.1 to 20 parts by weight per 100 parts by weight of metallic iron. In the oxygen-absorbing resin composition, when substantially all of the metal halide adheres to metallic iron and is not separated from metallic iron, the halogenated metal effectively acts on the oxygen-absorbing reaction of the main component. The compounding amount of the metal oxide is 0.1 to 5 parts by weight per 100 parts by weight of metallic iron.

The metal halide is blended in the thermoplastic resin together with metallic iron as a component of the oxygen scavenger composition, but it should be added in advance by mixing so as not to be easily separated from the metallic iron in the resin. Is preferred. For example, Raikai Machine,
A method of pulverizing and kneading a metal halide and iron powder by using a ball mill, a speed mill, etc., a method of embedding fine metal halide particles in recesses on the surface of the iron powder, a metal halide on the surface of the iron powder using a binder. Examples of the method include a method of adhering, a method of mixing an aqueous metal halide solution and iron powder, and then drying and adhering it to the surface of iron powder. In order to confirm the adhesion state of the metal halide to the iron powder in the oxygen scavenger composition, analysis by an electron beam microanalyzer is suitable, and the metal halide is formed in the metal iron particles captured by the SEM image. Since the halogen element and the metal element are present together with iron as an electron beam image, it can be confirmed that the metal halide is attached to the surface of the iron powder.

Examples of the alkaline earth metal oxides include magnesium oxide, calcium oxide, strontium oxide, and barium oxide. Magnesium oxide or calcium oxide is particularly preferable in terms of availability and reactivity. Alkaline earth metal oxides are also preferably used in a granular form, and the size of the particles is preferably in the range of 1 to 200 μm in average particle size, more preferably in the range of 1 to 50 μm, and the particle size of the oxygen scavenger composition It is desirable that they are equivalent or finer. However, if the fine particles become too fine, the hygroscopicity becomes too strong, which is inconvenient for storage and handling,
In addition, the oxygen-absorbing resin composition may undesirably adhere to metallic iron, and the particle size of the alkaline earth metal oxide should be appropriately selected within the above range.

The oxygen absorber composition has an oxygen permeability coefficient of 200 cc.
It is preferable to mix it with a thermoplastic resin of 0.1 mm / m ² · day · atm (23 ° C, 100% RH) or more. As the thermoplastic resin with which the oxygen scavenger composition is mixed, various polyethylene, polypropylene and polybutene can be used. , Polymethylpentene, polymethylmethacrylate, various ethylene copolymers, polyvinyl chloride, polyamides, polycarbonates, polyesters and modified resins thereof can be used alone or as a mixture. Among the above resins, polyethylene, polypropylene, polybutene, polymethylpentene, various ethylene copolymers and modified products thereof are selected as those having excellent oxygen permeability.

The content of metallic iron in the oxygen absorbing resin composition is 2 to 93% by weight, preferably 10 to 70% by weight. If the metallic iron content is lower than the above range, sufficient oxygen absorption performance cannot be obtained, and if it is too high, problems occur in the mechanical strength and moldability of the resin composition. The alkaline earth metal oxide content in the oxygen-absorbing resin composition is 0.1.
-5 wt% is preferable. The content of the alkaline earth metal oxide is too and no sufficient improving effect is obtained storability intended purpose small, whereas too much, since to affect oxygen absorption performance in use, an alkaline earth the content of metalloid oxides must be selected appropriately Te within the above range.

The oxygen-absorbing resin composition of the present invention is prepared by kneading a deoxidizer composition, an alkaline earth metal oxide and a thermoplastic resin, and adding the oxygen absorber composition and the alkaline earth metal into the thermoplastic resin. It is obtained by sufficiently dispersing the oxide. The mixing and kneading of the oxygen scavenger composition and the alkaline earth metal oxide to the thermoplastic resin can be performed by a stirring blade type mixer, a twin screw extruder, or the like. In this case, the oxygen scavenger composition and the alkaline earth metal oxide may be mixed in advance or added separately. In addition, a masterbatch method is used to prepare two resin compositions in which a deoxidizer composition or an alkaline earth metal oxide is mixed with a thermoplastic resin,
It is also possible to further add a thermoplastic resin to both of them, and to extrude them together from a single-screw extruder and knead them. In the oxygen-absorbing resin composition of the present invention, by sufficiently kneading by the above method, the oxygen absorber composition particles and the alkaline earth metal oxide particles are sufficiently dispersed, and both are substantially heated. It is in a dispersed state separated by the plastic resin. However, when a mixture of the oxygen scavenger composition and the alkaline earth metal oxide is used, sufficient care must be taken not to allow the mixture to absorb moisture, and the oxygen absorber composition and the alkaline earth metal oxide are also required. It is necessary to select an appropriate mixing and kneading method so that the oxygen absorber composition and the alkaline earth metal oxide are sufficiently dispersed in the thermoplastic resin, depending on the blending amount.

If necessary, the oxygen-absorbing resin composition may include organic or inorganic dyes, colorants such as pigments, silane- or titanate-based dispersants, and polyacrylic acid-based water-absorbing agents. Fillers such as clay, mica, silica, and starch, and gas absorbents such as zeolite and activated carbon can be added.

In the oxygen-absorbing laminate of the present invention, the oxygen-absorbing resin layer composed of the above-mentioned oxygen-absorbing resin composition is used as an intermediate layer, and at least one of the separating layers laminated on both sides thereof is a breathable separating layer. It is a laminated body. The oxygen-absorbing laminate of the present invention (hereinafter, may be simply referred to as a laminate) can have various laminated structures depending on the application, and can be roughly classified into a barrier material and a non-barrier material. it can.
The barrier material is one in which a gas barrier isolation layer is formed on one surface and an air permeable isolation layer is formed on the other surface. The non-barrier material is one in which a breathable isolation layer is formed on both surfaces of the oxygen-absorbing resin layer.

The gas barrier isolation layer preferably has an oxygen permeability of 50 cc / m ² .day.atm (23 ° C., 100% RH) or less. For the gas barrier isolation layer, a thermoplastic resin having low oxygen permeability such as polyester, polyamide and ethylene-vinyl alcohol copolymer, a film laminated with metal foil such as aluminum and tin, a film deposited with aluminum, silica and the like, etc. Is used. If necessary, a reinforcing layer, a recycle layer, or an adhesive layer for reinforcing the strength of the laminate can be provided on the gas barrier isolation layer side of the laminate.

As the air-permeable isolation layer, various thermoplastic resins used for blending the oxygen absorbent can be used. Particularly, those having excellent oxygen permeability are polyethylene, polypropylene, polybutene, polymethylpentene and various ethylene. Copolymers and modified products thereof are preferably used. Since the air permeability of the air-permeable isolation layer becomes thinner, the air permeability is improved. Therefore, it is preferable that the air permeability isolation layer is thin. However, the film thickness is 10 to 200 μm, preferably 10 to ensure moldability and hiding property.
To 100 μm. Further, for example, a dye or pigment for concealing or coloring, an additive for controlling heat-sealing property, or the like can be added to the resin layer forming the air-permeable isolation layer.

As additives for adjusting the heat-sealing property, ethylene-propylene random copolymer (abbreviated as random PP), ethylene-α-olefin copolymer (various LLDPE and elastomers), ethylene-acid copolymer, ionomer, One kind or two or more kinds can be selected from resins such as carboxyl-modified polyolefin and polystyrene. The addition amount is preferably selected in the range of 10 to 40% by weight of the resin layer.

When polymethylpentene is used for the breathable isolation layer, polymethylpentene and a polyolefin such as polyethylene or polypropylene are used in order to make up for the drawbacks of polymethylpentene, which is very excellent in oxygen permeability but poor in adhesiveness. It can be a mixed resin. Further, the polymethylpentene used may contain other resins. The mixed resin of polymethylpentene and polyolefin has a sea-island structure in the matrix because the polymethylpentene and polyolefin have poor compatibility in the range of polymethylpentene content of 10 to 80% by weight. The excellent oxygen permeability of polymethylpentene can be utilized even by mixing. In addition, the mixed resin has a pearly luster and has a high-class appearance.

Therefore, when polymethylpentene is used for the air-permeable isolation layer, the same resin as that used for the oxygen-absorbing resin layer is mixed in order to ensure thermal adhesiveness with the oxygen-absorbing resin layer. The content of polymethylpentene is 50% by weight or less, preferably 10 to 40% by weight. In this case, the resin forming the oxygen-absorbing resin layer should contain either polyethylene or polypropylene in an amount of 50% or more, preferably 60% or more. As a result, the breathable isolation layer and the oxygen-absorbing resin layer can secure good adhesion during coextrusion or thermocompression bonding, have excellent oxygen permeability, and have a laminate having a breathable isolation layer with an excellent appearance. Obtainable.

As the method for manufacturing and molding the above-mentioned laminate, known resin molding techniques such as multi-layer coextrusion molding using T-die and circular die, vacuum forming,
Sheet molding methods such as pressure molding, multi-layer blow molding methods such as direct blow and stretch blow, injection molding methods such as co-injection and multi-color injection, and heat lamination, dry lamination, extrusion lamination, hot melt lamination, etc. Known converting techniques such as a laminating method and various coating methods, or a combination thereof can be used.

The laminate of the present invention is used as an oxygen-absorbing barrier material or non-barrier material in packaging materials and packaging containers. As the barrier material, a film, a tray, a cup, a tube, a bottle, or the like is used, and it is used as a part or all of the outer packaging material of the packaging container, and if necessary, combined with a general gas barrier film or closures. Can be used. For example, as a container such as a tray or a bottle, the opening is sealed with a gas barrier member as shown in FIGS. Further, it is a top seal film for a container as shown in FIG. The non-barrier material is mainly in the form of a sheet such as a mount, a partition or the like, a tray, a container such as a bottle, the former is inserted into the inside of the packaging container as a part of the packaging material, and the latter stores the preserved object. After that, it is further packaged and used in a gas barrier film or the like.

The oxygen-absorbing resin composition, the laminate and the product comprising the same of the present invention can be easily handled in the atmosphere during the production process, distribution process and use. But,
It is desirable to use simple moisture-proof packaging for storage, and moisture-proof packaging is preferable for long-term storage.

[0031]

EXAMPLES The effects of the present invention will be specifically described by showing Examples and Comparative Examples of one embodiment of the present invention. The present invention is not limited to the examples below. Example 1 100 kg of reduced iron powder having an average particle diameter of 30 μm was put into a vacuum mixing dryer with a heating jacket, and while heating at 140 ° C. under reduced pressure of 10 mmHg, 7 kg of a 20 wt% calcium chloride aqueous solution was sprayed and dried, The particles were sieved to remove coarse particles of 300 mesh over to obtain a granular oxygen absorber composition. Next, an ethylene-propylene copolymer and the above oxygen scavenger composition were kneaded at a weight ratio of 2: 3 using an extruder including a vented 45 mmφ co-rotating twin-screw extruder and a constant-volume feeder, and then extruded from a strand die. After extruding, it was air-cooled and crushed to obtain a masterbatch A. Similarly, using the above-described extruder, calcium oxide having an average particle size of 20 μm and an ethylene-α-olefin copolymer were kneaded at a weight ratio of 1: 1 to obtain a masterbatch B.

Next, the first to fifth extruders, feed blocks, T dies, cooling rolls, take-up devices, slitters,
The resin composition shown in Table 1 was extruded from each of the first to fifth extruders using a 5 type 6-layer multi-layer sheet forming apparatus composed of a winder, and layer 3 / layer 2 / layer 13 shown in FIG.
/ Layer 14 / Layer 15 / Layer 16 was laminated to form a laminated sheet (width: 650 mm). The surface of the obtained laminated sheet was quite smooth and good. In addition, each layer of the above-mentioned laminated sheet includes layer 3; breathable isolation layer (60 μm), layer 2; oxygen-absorbing resin layer (140 μm), layer 13; adhesive layer (15 μm), layer 14; gas barrier layer (20 μm). ,
The layer 15 serves as an adhesive layer (15 μm) and the layer 16 serves as a strength retaining layer (250 μm) (the thickness in () indicates the film thickness). The laminated sheet produced above was wound around a vinyl chloride pipe (inner diameter: 3 inches) in units of 50 m, and wrapped with a moisture-proof film made of aluminum foil laminated polypropylene for storage.

[0033]

[Table 1]

Comparative Example 1 Of the compositions extruded from the second extruder of Example 1, the composition according to Masterbatch B was not used, but the ethylene-propylene copolymer was changed to 2% by weight, and Example 1 was used. A laminated sheet was manufactured in the same manner as in. When the obtained laminated sheet was observed, unevenness was generated on the surface of the layer 3 (air-permeable isolation layer) and smoothness was lost, and bubbles were generated in the layer 2 (oxygen-absorbing resin layer). Was there.

Comparative Example 2 In the preparation of the masterbatch A in Example 1, the oxygen scavenger composition was previously dried by using an electric furnace in a nitrogen gas atmosphere at 300 ° C. for 1 hour to perform a drying treatment in advance. A laminated sheet was produced in the same manner as in Comparative Example 1 except that the agent composition was used in Masterbatch A. When the obtained laminated sheet was observed, the surface of the sheet was smooth and good as in Example 1.

Example 2 A package of a laminated sheet which was wound in 50 m units in Example 1 and was simply moisture-proof packaged with an aluminum foil laminated polypropylene film was opened 2 months later, and a vacuum forming machine (15 tray types) was opened. Using the laminated sheet of Example 1 with the layer 3 (breathable isolation layer) side inside, a tray-shaped container (vertical 1
It was molded into 30 × width 90 mm × depth 25 mm, internal volume 270 cc). Hereinafter, the tray-shaped container is simply referred to as a tray. When the molding state of the obtained tray was observed, it was extremely good.

Comparative Example 3 The laminated sheet produced in Comparative Example 2 was wound on a pipe in the same manner as the laminated sheet of Example 1, wrapped with a moisture-proof film made of aluminum foil laminated polypropylene and taped, and this was further It was put in a vinylidene chloride-coated nylon / polyethylene laminated film bag, and the bag mouth was heat-sealed and sealed, and stored in a double-wrapped form. The laminated sheet of Comparative Example 2 that had been double-wrapped and stored for 2 months was opened, and immediately, this laminated sheet was vacuum-formed under the same conditions as in Example 2 and formed into a tray. When the molded state of the obtained tray was observed, not only was the tray foamed and spoiled its aesthetic appearance,
The isolation layer (layer 3) was partially broken and the oxygen-absorbing resin layer (layer 2) was exposed, and it could not be used as a tray.

Example 3 180 g of red rice was placed in the molding tray obtained in Example 2,
A top film in which polyester / aluminum foil / polypropylene was laminated was heat-sealed and hermetically sealed in the opening of the molding tray. The sealed tray was left at room temperature, and the oxygen concentration in the tray was analyzed by gas chromatography after 4 days, 10 days, and 2 months, respectively. The results are shown in Table 2.

Comparative Example 4 The laminated sheet produced in Comparative Example 2 was immediately vacuum formed into a tray, red rice was placed in the obtained forming tray, and the oxygen concentration in the tray was measured in the same manner as in Example 3. The results are shown in Table 2.

[0040]

[Table 2]

Example 4 The molding tray manufactured in Example 2 was once stored in a nylon laminated polyethylene bag having a bag mouth closed with a rubber band for two months, and then red rice was placed in this tray. Similarly, the oxygen concentration in the tray was measured. The results are shown in Table 2.

Comparative Example 5 As in Example 4, the molding tray produced in Comparative Example 4 was immediately stored in a nylon laminated polyethylene bag having a bag mouth closed with a rubber band, and then red rice was placed in this tray. The oxygen concentration in the tray was measured in the same manner as in Example 3. The results are shown in Table 2.

Example 5 100 kg of reduced iron powder having an average particle size of 35 μm was put into a vacuum mixing dryer having a heating jacket, and the temperature was 130 ° C. and 10 mm.
While heating under reduced pressure of Hg, to 100 parts by weight of iron powder,
Calcium chloride: sodium chloride: water = 0.5: 0.
A mixed aqueous solution of 5: 2.5 (each part by weight) was sprayed, sufficiently dried, and then sieved to remove fine powder of 300 mesh over to obtain a granular oxygen scavenger composition. Next, using an extrusion device consisting of a 45 mmφ co-rotating twin-screw extruder with a vent and a quantitative feeder, the kneading was carried out at a polypropylene: oxygen scavenger composition = 2: 3 weight ratio, followed by cooling with a net belt with a blower, and then a pelletizer. To obtain pellets of the oxygen-absorbing resin composition. Using the 5-kind 6-layer multilayer sheet molding apparatus of Example 1, the resin compositions shown in Table 3 were extruded from the first to fifth extruders, respectively, and shown in FIG.
A laminated sheet (width 650 mm) was manufactured by laminating layers 13 / layer 14 / layer 15 / layer 16 in this order. Here, the first
A composition comprising white pigment-added polypropylene / polymethylpentene / polyethylene = 60/30/10 (weight ratio) was extruded from the extruder to form Layer 3; a breathable isolation layer. (Polypropylene with white pigment; polypropylene /
Titanium oxide = 80/20 weight ratio of composition, polymethylpentene; TPX manufactured by Mitsui Petrochemical) The film thickness of each layer of the laminated sheet is as follows. Layer 3 (breathable isolation layer); 50 μm, Layer 2 (oxygen absorbing resin layer); 120
μm, layer 13 and layer 15 (adhesive layer); 15 μm, layer 1
4 (gas barrier layer); 20 μm, layer 16 (strength retaining layer); 300 μm Next, using a vacuum forming machine, the layer 3 (breathable isolation layer) side of the above laminated sheet is placed inside and the temperature is 185.
Plug-assisted molding was carried out at ℃ to obtain a cup (diameter 60 mm × depth 35 mm, internal volume about 90 cc). The molding condition of the cup was good. 80 cc of hot water was put into the obtained tray, and then the top film laminated with PET (12 μm) / aluminum (40 μm) / PE (28 μm) was heat-sealed using a cup sealer. The sealed cup was left at room temperature, and the oxygen concentration in the cup after 3 days and 10 days was analyzed by gas chromatography.
The results are shown in Table 4.

[0044]

[Table 3] Note) White pigment added PP: Polypropylene / Titanium oxide = 80/20 (weight ratio)

Comparative Example 6 The resin composition of Layer 3 extruded from the first extruder in Example 5 was used as a white pigment-added polypropylene (polypropylene /
A laminated sheet was produced in exactly the same manner as in Example 5 except that the composition was changed to titanium oxide = 80/20 weight ratio). Then, the obtained laminated sheet was formed into a cup in the same manner as in Example 5, hot water was put into this cup, and heat sealing was performed with a top film. The oxygen concentration in the cup after 7 days and 14 days after leaving the sealed cup at room temperature was analyzed by gas chromatography. The results are shown in Table 4.

[0046]

[Table 4]

Example 6 In the multilayer sheet produced by using the 5-type 6-layer multilayer sheet molding apparatus in Example 5, the resin composition extruded from the first extruder was changed, and the multilayer sheet was prepared in the same manner as in Example 5. Manufactured. The resin composition extruded from the first extruder is A
Components: White pigment-added polypropylene and B component were used. The B component was changed as shown in Table 5 to obtain 5 kinds of multilayer sheets. In Table 5, the ratio of A: B is shown by weight ratio. The obtained five kinds of multilayer sheets were formed into a cup, and then, using a cup sealer, a top film made of nylon / ethylene vinyl alcohol copolymer / polyethylene was heat-sealed at 180 ° C. at the mouth of each cup. The top film of the heat-sealed cup is cut into 15 mm width in the radial direction centering around the center of the circle to the peripheral seal part, and one end of the 15 mm wide strip-shaped top film cut out in the middle is used with a push-pull gauge. Then, the seal strength when the seal portion was peeled from the cup was measured. The results are shown in Table 5.

[0048]

[Table 5]

[0049]

EFFECTS OF THE INVENTION In the present invention, an oxygen-absorbing resin composition excellent in oxygen-absorbing performance is obtained by solving the first problem by blending and dispersing an alkaline earth metal oxide in an oxygen-absorbing resin. The laminated body and the molded product made of the same can be stored in a simple moisture-proof package for a long period of time without impairing the oxygen absorption performance, and the storage property can be improved significantly. According to the present invention, the oxygen-absorbing resin composition or the raw material of the laminate, it is possible to prevent moisture absorption in the intermediate product stage, there is no expiration of the oxygen absorption capacity, there is no problem such as foaming during molding It has excellent properties, and is practically easy to handle in the manufacturing process and storage. Further, similarly, the molded product can be easily stored without deteriorating the oxygen absorption capacity. Further, according to the present invention, the second problem is solved by using a mixed resin of polymethylpentene and polyolefin as an air-permeable isolation layer, and the poor adhesiveness of polymethylpentene is compensated for, and oxygen permeability is improved. It is possible to obtain an oxygen-absorbing laminate having an excellent air-permeable separating layer, and thus a packaging material and a packaging container having excellent oxygen-absorbing properties can be obtained.

[Brief description of drawings]

FIG. 1 is an oxygen-absorbing laminate (barrier material) according to the present invention.
It is sectional drawing of an example.

FIG. 2 is a sectional view of an example of an oxygen-absorbing laminate (non-barrier material) according to the present invention.

FIG. 3 is a cross-sectional view of a container including the oxygen-absorbing laminate according to the present invention.

FIG. 4 is a cross-sectional view of a wide-mouth bottle made of an oxygen-absorbing laminate according to the present invention.

FIG. 5 is a sectional view of another wide-mouth bottle including the oxygen-absorbing laminate according to the present invention.

FIG. 6 is a cross-sectional view showing a state in which a lid made of an oxygen-absorbing laminate according to the present invention is put on a container.

[Explanation of symbols]

1 Gas barrier isolation layer 2 Oxygen absorbing resin layer 3 Breathable isolation layer 3'breathable isolation layer 13 Adhesive layer 14 barrier layer 15 Adhesive layer 16 Reinforcing layer 20 containers 30 lid 40 Top seal

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B32B 27/32 103 B32B 27/32 103 B65D 81/26 B65D 81/26 R C08K 3/22 C08K 3/22 C08L 23/02 C08L 23/02 (56) Reference JP-A-1-278335 (JP, A) JP-A-7-82445 (JP, A) JP-A-4-173868 (JP, A) JP-A-63-168348 (JP, A) JP 63-137838 (JP, A) JP 60-158257 (JP, A) JP 55-90535 (JP, A) JP 4-90848 (JP, A) JP 1 −278344 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 B32B 7/00 B32B 9/00 B32B 27 / 32 B65D 81/26

Claims (6)

(57) [Claims] 1. Oxygen permeability coefficient of 200 cc / 0.1 mm / m ² / day / atm
(23 ° C, 100% RH) Deoxidizer composition and alkaline earth metal oxide mainly composed of metallic iron that obtains water to cause oxygen absorption reaction in a thermoplastic resin having excellent oxygen permeability that is not less than 23 ° C But oxygen absorption
The iron content in the compatability resin composition is from 2 to 93% by weight.
%, Alkaline earth metal acid in oxygen-absorbing resin composition
A resin composition in which the oxide content is 0.1 to 5 wt% and the alkaline earth metal oxide is separated from the oxygen scavenger composition by the thermoplastic resin. An oxygen-absorbing resin composition characterized by being present. 2. A deoxidizer composition or an alkaline earth metal oxide is added to a thermoplastic resin having excellent oxygen permeability, respectively.
The oxygen-absorbing resin composition according to claim 1, which is prepared by preparing a resin composition of one kind, extruding the resin composition together, and kneading the resin composition. 3. An oxygen scavenger composition containing metallic iron as a main component, which obtains water and causes an oxygen absorption reaction, is added by previously mixing 0.1 to 5 parts by weight of metal halide per 100 parts by weight of metallic iron. The oxygen-absorbing resin composition according to claim 1, which is a deoxidizer composition obtained by 4. An oxygen-absorbing laminate, wherein at least one of the intermediate layer made of the oxygen-absorbing resin composition according to claim 1 and the separating layer laminated on both surfaces thereof is a breathable separating layer. 5. Oxygen permeability coefficient 200 cc / 0.1 mm / m ² day / atm
(23 ℃, 100% RH) or more in a thermoplastic resin having excellent oxygen permeability, oxygen scavenger composition or alkaline earth metal oxidation mainly composed of metallic iron that obtains water to cause oxygen absorption reaction A method for producing an oxygen-absorbing resin composition, which comprises a step of mixing two materials to prepare two resin compositions, and a step of extruding and kneading the resin compositions together. 6. Oxygen-absorbing resin composition containing metallic iron
2 to 93% by weight in the oxygen-absorbing resin composition.
Lucari earth metal oxide content is 0.1-5% by weight
The manufacturing method according to claim 5.