JP3006731B2 - Container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container having a function of absorbing oxygen in the container, and more particularly, to salad oil,
Oil storage containers requiring long-term storage such as tempura oil, corn oil, rapeseed oil, sesame oil, storage containers for solvents such as ethers that generate peroxide by absorbing oxygen in the air, beer, oolong tea, Japanese tea, The present invention relates to a container suitable for use as a bottle of a beverage or the like which is liable to be deteriorated by oxidation such as tea and coffee.

[0002]

2. Description of the Related Art If the contents of a container are susceptible to oxygen oxidation, various problems may occur during the storage period or the like. For example, edible oils are susceptible to changes in quality due to oxidation, and the occurrence of food poisoning substances due to oxidation products has been regarded as a problem. This is due to the fact that the contents are oxidized by a trace amount of oxygen present in the container or oil or oxygen entering from outside the container during the storage period. In order to solve this problem, storage of cans and use of an oxygen absorbent have been conventionally performed.

[0003] However, once the can is opened, it is difficult to shield the air, and there is a problem that even a sealable resin container has oxygen that penetrates through the container. In order to address these problems, there is a simple method of using an oxygen absorber.However, since the oil resistance of the package and the oil shielding effect are insufficient, the oxygen absorber containing the oxygen absorber and the oil are used. Contact cannot be avoided, and there have been problems such as a decrease in the activity of the oxygen absorber and an erroneous consumption of the eluate from the inside of the package. As a method for improving the shielding effect, the interposition of a film is conceivable. However, in this case, the permeability of oxygen is reduced, and a sufficient oxygen absorbing effect cannot be expected. The solution is to reduce the thickness of the film. However, 1
Films below μm generally have poor mechanical strength, making it impossible to apply a uniform thin film layer. Furthermore, there has been no known oxygen-permeable material which is excellent in thin film forming property and has sufficient oil resistance.

[0004] In the case of ether-based solvents and the like, they react with oxygen present in a container or a solvent or invading from the outside during the storage period to form explosive peroxides. Great care was required. Therefore, for example, diethyl ether is stored in a refrigerator, and tetrahydrofuran (THF) is stored by adding butylhydroxytoluene or the like as an antioxidant.

However, even when stored in a refrigerator, the formation of peroxide cannot be completely suppressed, and addition of an antioxidant often requires removal by distillation or the like at the time of use. A storage method that does not generate oxides has been desired. Particularly, the presence of peroxide is a serious problem when distillation purification is required. In order to suppress the generation of peroxide, there is a method of storing in a container having a high air-shielding property, but advanced technology was required to expect a sufficient shielding effect.

Furthermore, in beverages and the like which are liable to be deteriorated by oxidation, the amount of oxygen present in containers and beverages is reduced as much as possible to prevent deterioration of taste and quality over a long period of time. Is desired.

[0007] In order to cope with such various problems and demands in the related art, it is effective to use an oxygen absorber having an oxygen absorbing performance and to minimize the amount of oxygen present in the container or in the contents of the container. is there. Further, in the case of a resin bottle or the like, since oxygen enters into the inside through the container body, it is also desired to prevent the oxygen from entering.

[0008] As a conventional method using an oxygen absorber, for example, a method of fixing an oxygen absorbent to a beer cap or the like is known. This method involves embedding an oxygen absorbent in a resin and / or fixing the oxygen absorbent to a beer crown or the like via a shielding material (for preventing the oxygen absorbent from coming into direct contact with the beer). Can be classified.

(1) As a method of embedding an oxygen absorbent in a resin, JP-A-1-308781 and JP-A-1-308781
A method disclosed in Japanese Patent Publication No. 315438 is exemplified. In the former, a mixture of low-density polyethylene, ascorbic acid and / or sodium sulfite, a lubricant (sodium dodecyl sulfate), and an antioxidant is fixed to the back of the crown to prolong the shelf life of beer. In the latter, polypropylene containing ascorbic acid is attached to a cap to improve the storage stability of beer. European Patent No. 305005 discloses that dried yeast is immobilized in a molten paraffin slurry, applied to a fixed thickness, and heat treated to improve the stability of beer.

(2) As a method for fixing the oxygen absorbent via a shielding material, Japanese Utility Model Laid-Open Nos. 55-161858 and 56-38056, US Pat. No. 4,287,
No. 995, US Pat. No. 4,421,235,
U.S. Pat. No. 4,756,436 is an example. In these methods, the oxygen absorbent is shielded by a water-impermeable sheet while being permeable to oxygen, thereby preventing contact between the contents of the container and the oxygen absorbent, thereby achieving efficient oxygen absorption. It is. The sheet has a pore size of 0.01 to 0.45.
Those made of polyethylene, polypropylene or polyfluoroethylene having a thickness of μm can be used. These sheets may be coated on the surface with a silicone resin or polyfluorocarbon to further increase the water repellency. Examples of the oxygen absorbent include iron, iron sulfate, iron chloride, dithionate, dithionite, ascorbic acid and its salts, catechol, hydroquinone, pyrogallol, Rongalit, copper-
Amine complexes and the like are mentioned. PC
T-WO89 / 12119 discloses a method in which a metal complex of a polyalkylamine is fixed on silica gel and a water-insoluble oxygen absorbent is fixed together with a gas-permeable shielding material to the beer crown or the inside of canned beer. It has been disclosed.

(3) As a method of fixing an oxygen absorbent to a crown or the like, a method of embedding the oxygen absorbent in a resin and further interposing a shielding material is disclosed in JP-A-57-194959. . In this method, an oxygen absorbent is dispersed in an elastomer and fixed to the inside of a container lid, and a polymer coating that allows oxygen and water vapor to pass therethrough but does not allow water to pass therethrough is provided thereon.

[0012]

However, the above prior art using an oxygen absorber has the following problems. A first problem is that it is difficult to shield the oxygen absorbent from the contents while maintaining sufficient oxygen permeability. In the method of embedding the oxygen absorbent in the resin, contact between the oxygen absorbent and the contents cannot be avoided. As a method of solving this problem, a method of fixing an oxygen absorbent via a shielding material has been proposed. As the shielding material, a sheet (non-porous film), a porous film, and a porous film subjected to a water-repellent treatment are used. When a sheet is used, a material having high oxygen permeability is selected, but a thickness on the order of μm or more is required to ensure mechanical strength. However, there is a problem that the oxygen permeability becomes extremely small when the film thickness is about this level. When a porous membrane is used, since it has a pore size of the order of μm or more, oxygen permeability is high, but it is difficult to completely shield the oxygen absorbent. In particular, in a system such as beer in which the inside of the container is pressurized during the storage period, this problem becomes remarkable. In order to solve this, a method of coating a water-repellent polymer on a porous film has been proposed. However, in the solution coating method, there is a problem that the polymer penetrates into the pores and oxygen permeability decreases. That is, in the prior art, it is difficult to reduce the thickness of the shielding sheet or to control the fine pore diameter of the porous film, so that a sufficient shielding effect cannot be obtained while maintaining oxygen permeability.

[0013] The second problem is that it is difficult to store the oxygen absorber containing the oxygen absorbent. In many cases, the oxygen absorber is stored in air from the time it is manufactured until it is installed. Therefore, the oxygen absorber absorbs oxygen in the air during the storage period and cannot be put to practical use if most of its oxygen absorbing capacity is already exhausted when worn. In order to solve this problem, a method has been known in which oxygen absorbers are given a function, do not absorb oxygen during storage, and begin to absorb oxygen by applying some stimulus after wearing an oxygen absorber. ing. For example, PCT-WO89 /
No. 12119 discloses that a polyalkylamine fixed on silica gel, which is an oxygen absorption precursor, is mixed with a metal salt, and the metal salt is dissolved by water in the system and incorporated into the polyalkylamine, thereby exhibiting oxygen absorption. Such a method is disclosed. However, there are problems that the preparation of the polyalkylamine fixed on silica gel is complicated and that sufficient oxygen absorption cannot be exhibited under low humidity.

A third problem is that when the container body is made of resin, little consideration is given to preventing oxygen from entering through the container body. If a large amount of oxygen enters through the container body, it becomes difficult to store the beverage for a long time as described above for a long period of time, and it is difficult to extend the expiration date and prevent deterioration in quality.

An object of the present invention is to provide a novel container provided with an oxygen absorber. In providing the oxygen absorber on the inner surface side of the container, the oxygen absorber is reliably shielded from the contents of the container while the oxygen absorber is shielded from the contents of the container. An object of the present invention is to make it possible to maintain a high oxygen permeation rate to an absorber and to maintain a high oxygen absorption performance until the oxygen absorber is used in a container.

It is also an object of the present invention to desirably prevent entry of oxygen through the container body in the case of a resin container.

[0017]

In order to achieve this object, a container according to the present invention comprises at least a part of an inner surface of a container body, an oxygen absorber layer in which an oxygen absorbent is embedded in a resin,
An oxygen permeable layer having an asymmetric porous layer in which a dense thin film layer is formed on the inner side of the container with respect to the oxygen absorber layer and on the inner side of the container in the thickness direction.

The “asymmetric porous layer” in the present invention is:
This layer is necessary to solve the first problem described above, that is, to make it possible to shield the oxygen absorber from the contents while maintaining sufficient oxygen permeability. In the present invention, the asymmetric porous layer refers to a layer comprising a very thin dense layer on one side of a flat membrane sheet and a porous layer supporting the dense layer. The dense thin film layer has Angstrom level holes required for oxygen transmission, so the shielding effect of the contents is much larger than that of the conventional porous film. The performance can be significantly higher than that of a conventional sheet. In other words, a sufficiently high oxygen permeability can be exhibited while achieving a sufficiently high content shielding effect. This dense thin film layer is supported by a porous layer having high oxygen permeability. In addition, when there is a possibility that a sufficient shielding effect cannot be expected with only the asymmetric porous layer, such as when the pressure in the container increases, an oxygen-permeable homogeneous thin film layer is further provided on the dense thin film layer. Thereby, the shielding effect can be further improved without significantly lowering the oxygen permeability. The oxygen-permeable layer having an asymmetric porous layer may be in the form of a so-called “oxygen-permeable composite membrane” that is supported by a woven or nonwoven layer so as to withstand use under pressure.

The "oxygen absorber layer in which the oxygen absorbent is embedded in the resin" in the present invention is a layer that absorbs oxygen in the container and in the contents, and solves the second problem described above. That is, it is a layer necessary for improving the storage stability and maintaining the form until the oxygen absorber is actually used in the container. As the oxygen absorbent in the present invention, those that exhibit oxygen absorbing ability under high humidity can be preferably used. However, such an oxygen absorbent itself is deactivated when activated to some extent by moisture in the air. Therefore, by embedding the oxygen absorbent in a resin that allows moisture and oxygen to pass under high humidity without passing through moisture in a normal atmosphere, it is possible to prevent deactivation of the oxygen absorbent until it is actually used. . Therefore, by using this oxygen absorber layer, the storage stability until it is actually mounted can be improved, and the form as a laminate can be easily maintained.

Considering higher storage stability, it is also possible to provide an oxygen barrier film layer. The oxygen-barrier film layer is located between the oxygen-absorbing layer and the back surface of the container body when mounted in the container.
During the storage period before mounting, the presence of the oxygen barrier film layer prevents the oxygen absorber layer from being directly exposed to the atmosphere, so that a decrease in the oxygen absorption performance of the oxygen absorber layer is more reliably prevented. In addition, since the laminate has the oxygen barrier film layer, even when the container body is made of resin, the intrusion of oxygen from the outside through the container body is efficiently prevented, and the third problem described above can be solved. Becomes

The above-mentioned laminate is fixed to at least a part of the inner surface side of the container body, or at least a part of the container body is constituted by the laminate itself. The portion where the laminated body is provided is not particularly limited, and may be either the inner surface side of the inner space of the head space portion in the container, the inner surface side of the container where the contents are stored, or both.

Hereinafter, the container of the present invention, particularly each part of the laminate, will be described in more detail. (1) Asymmetric porous layer The asymmetric porous layer is composed of a very thin dense layer on one side of a flat membrane sheet and a porous layer supporting the dense layer. The dense layer existing on one side of the layer is formed as a very thin layer having pores of 0.0005 to 0.5 μm and a thickness of about several μm. Since the asymmetric porous layer has a thin dense layer and the subsequent porous layer has high porosity, the gas or water vapor permeation rate is very high. As a preferred embodiment of the present asymmetric porous layer, a dense thin film is required from the viewpoint of achieving both a shielding effect and an oxygen transmission rate, and in the case of providing an oxygen-permeable homogeneous thin film layer, from the viewpoint of forming the oxygen-permeable homogeneous thin film layer. The preferred pore size of the layer is between 0.001 and 0.1 μm. The total thickness of the asymmetric porous layer is usually 1 to 300 μm in order to have practical mechanical strength and to obtain a sufficient gas permeation rate.
m, and preferably 10 to 100 μm. Although it is possible to use a film structure having a symmetric structure in the film thickness direction, an asymmetric porous structure is necessary to achieve both a shielding effect and an oxygen permeation rate. By doing so, the gas permeation resistance can be reduced. The porosity of the entire film can be arbitrarily selected according to the purpose, but is generally selected from the range of 10 to 90%. If the porosity is high, the gas permeation speed is high, and if the porosity is low, the durability is excellent. However, in the present invention, the porosity is 70 to 85% in the sense of having both of these characteristics. A preferred example is an asymmetric porous layer. As the asymmetric porous layer, a layer formed by a known method, for example, a wet method, a dry-wet method, a melting method, a stretching method, or the like is appropriately used. Examples of the material forming the asymmetric porous layer include aromatic polysulfone-based materials such as polysulfone, polyether sulfone, polyphenylene sulfide sulfone, and polyphenylene sulfone; cellulose-based materials such as cellulose acetate, ethyl cellulose, and cellulose; polyacrylonitrile, polypropylene, and polyethylene. Polyolefin-based materials such as polyvinylidene fluoride, fluorine-containing polymer-based materials such as polytetrafluoroethylene, polyamide-based materials or polyimide-based materials and polyurethane-based materials can be used. And an aromatic polysulfone-based material is preferably used because the pore size is easily controlled. The gas permeability of the porous layer is 10 to 10,000 [m ³ / m ^2] at an air permeation speed.
.Hr.atm].

(2) Layer made of woven or nonwoven fabric As a support layer for supporting the asymmetric porous layer, a base layer made of woven or nonwoven fabric is provided, and oxygen permeation between the asymmetric porous layer and this support layer is provided. The layer may be in the form of a so-called “oxygen-permeable composite membrane”. The base layer made of the woven or nonwoven fabric preferably has sufficient air permeability and good mechanical strength. Examples of those having such properties include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyamides such as nylon, and known woven or nonwoven fabrics mainly containing natural fibers and the like. The air permeability of the woven or nonwoven fabric is not particularly limited as long as oxygen transmitted through the asymmetric porous layer does not cause a large resistance until it reaches the oxygen absorber layer. As the air permeability, for example, 0.01 to 100 [ml /
cm ² · sec], and in consideration of the film forming properties of the asymmetric porous layer and the performance of the oxygen absorber layer having a composite structure, 0.1 to 10 ml / cm ² · sec.
c) is particularly preferred. Further, the thickness is particularly preferably 50 to 300 μm from the viewpoint of the supporting strength. In the case of a nonwoven fabric, the basis weight corresponding to this performance is 10 to 20
A range of 0 g / cm ² can be mentioned as a suitable amount. Furthermore, when a woven or nonwoven fabric having heat sealing properties is used, the working efficiency during lamination can be increased.

(3) Oxygen-permeable homogeneous thin-film layer An oxygen-permeable homogeneous thin-film layer may be further provided on the oxygen-permeable layer inside the container. This oxygen permeable homogeneous thin film layer
It is a layer that more reliably prevents the permeation of liquid contents such as water and oil, and allows oxygen and water vapor to permeate. The oxygen permeability of the homogeneous oxygen-permeable thin film layer is such that when the oxygen permeability coefficient P _o2 is used, _{Po 2} is 1 × 10 ⁻¹⁰ [cm ³ (STP) · cm /
cm ² · sec · cmHg] (= volume / film thickness / film area / time / pressure of gas converted to standard state) or more, and more preferably 1 × 10 ⁻⁹ [cm ³ (STP) · cm /
cm ² · sec · cmHg] or more. The water vapor permeability depends on the temperature and pressure in the container, the contents of the container, and the characteristics of the oxygen absorbent, and thus cannot be unconditionally determined. However, as a rough guide, 0.5 [g / m ² · atm ·
24 hr] or more can be mentioned as a preferable example.

As the polymer satisfying the above range, for example,
Polyorganosiloxanes such as polydimethylsiloxane, polymethylphenylsiloxane, cross-linked polymer of polydimethylsiloxane derivative, polyorganosiloxane /
Polyorganosiloxane copolymers such as polystyrene copolymer, polyorganosiloxane / polycarbonate copolymer, polyorganosiloxane / polysulfone copolymer, poly (4-methylpentene-1), polyethylene / propylene copolymer, poly (4-methylpentene-
1) crosslinked polymer, polyolefins such as poly (di-tert-butyl fumarate), poly (2,6-dimethyl-1,4-phenylene oxide) and silyl-modified poly (2,6-dimethyl-1, Polyphenylene oxides such as 4-phenylene oxide), substituted acetylene polymers such as poly (trimethylsilylpropyne) and poly (tert-butylacetylene), celluloses such as ethylcellulose, and poly (bisethoxyphosphazene)
And polyorganophosphazenes.

In order to form a pinhole-free homogeneous oxygen-permeable thin film layer which enables high oxygen permeability, a polyorganosiloxane cross-linked polymer or poly (4-methylpentene-1) is used.
The crosslinked polymer of the above can be mentioned as a preferable example.
Examples of the crosslinkable modified polyorganosiloxane include silanol-modified polyorganosiloxanes represented by the following chemical formulas (1) and (2).

[0027]

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[0028]

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In the above formulas (1) and (2), R 1 and R 2 are methyl, ethyl, propyl or phenyl, and R 3 is
A methyl group, an ethyl group or a propyl group, and R4 has 2 carbon atoms.
Represents an alkyl group of up to 15 or a compound represented by the following formula 3. P + p ′ = 3 and p is an integer of 1 to 3, 0.001 ≦ m / (m + n) ≦ 0.20,
n + m represents an integer of 50 to 3000.

[0030]

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These compounds include silane crosslinking agents having high reactivity with silanol groups such as polyfunctional acetoxy silanes, oxime silanes, alkoxy silanes, alkenyloxy silanes, amide silanes, amino silanes, and the above silane crosslinking agents. Can be cross-linked by a siloxane cross-linking agent which is a hydrolyzate of Although the number of the functional groups is not particularly limited, tetrafunctional or more is preferred in consideration of the high reactivity and the ability to form a thin film on the microporous support and the strength of the thin film. Specific examples include tetraacetoxysilane, tetradimethyloximesilane, ethylorthosilicate, propylorthosilicate, tetrakisisopropenixisilane, ethylpolysilicate, pentadimethyloximesiloxane, hexadimethyloximesiloxane, hexaacetoxysiloxane, and the like. The reaction may include a catalyst to increase the reaction rate, such as dibutyltin acetate, dibutyltin octoate, and the like.

Examples of other polydimethylsiloxane derivatives include amino-modified polydimethylsiloxane represented by the following chemical formulas (4) and (5).

[0033]

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[0034]

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These compounds can be used as a polydimethylsiloxane derivative by a polyfunctional compound having two or more functional groups such as acid chloride, acid anhydride, isocyanate, thioisocyanate, sulfonyl chloride, epoxy, aldehyde and active halogen in the molecule. It can be a crosslinked polymer.
Among them, acid chlorides, isocyanate compounds, and aldehyde compounds have high reactivity and are particularly preferable. For example, isophthalic acid dichloride, terephthalic acid dichloride, trimesic acid chloride, fumaric acid dichloride, tolylene-2,
4-diisocyanate, diphenylmethane-4,4,-
Examples include diisocyanate, glutaraldehyde, and phthalaldehyde.

Examples of the crosslinked poly (4-methylpentene-1) include self-crosslinked trimethoxyvinylsilane-grafted poly (4-methylpentene-1). However, as long as the oxygen permeability coefficient substantially satisfies the above range, it is possible to use without being limited to these. Further, the polymer forming the oxygen-permeable homogeneous thin film layer may be added with another polymer as long as the permeability of the thin film layer is not impaired, and a mixing method using two or more kinds of the above polymers, There is a lamination method and the like.

As the method for forming the oxygen-permeable homogeneous thin film layer, any method such as a polymer coating method, an interfacial polymerization method of monomers, a method of crosslinking a crosslinkable polymer after coating, and a plasma polymerization method can be used. However, when the thickness of the thin film is too small, the mechanical strength of the thin film layer decreases, and when the thickness is too large, the oxygen transmission rate decreases. 05
Suitably, it is で 1 μm.

(4) Oxygen-permeable composite membrane A laminate comprising an asymmetric porous layer and a woven or non-woven fabric support layer is referred to as an "oxygen-permeable composite membrane" in the present invention. The oxygen-permeable composite membrane may further be provided with an oxygen-permeable homogeneous thin film layer on the asymmetric porous layer. The oxygen-permeable composite membrane is a composite membrane composed of a support layer made of a woven or non-woven fabric and an asymmetric porous layer provided on the support layer, or a support layer or an asymmetric type provided on the support layer. Although no problem as long as the composite film structure comprising a porous layer and the oxygen permeable homogenous thin layer provided on the non-symmetric porous layer, 0.1 is the oxygen permeation rate Q _O2
Those of 50 [m ³ / m ² · hr · atm] are preferable,
More preferably, 0.5 to 15 [m ³ / m ² · hr · at
m]. If the oxygen permeation rate is lower than the above range, the oxygen absorption rate of the oxygen absorber decreases, which is not preferable.If the oxygen permeation rate exceeds the above range, the oxygen permeable composite membrane is contacted with other substances. However, it is not preferable because it is easily damaged. For water vapor permeability,
1.0 g / m ² · at to activate the oxygen absorber
m · 24 hr] or more. In particular, in the case of foods and beverages which are easily oxidized, 10 g / m ² · atm
.24 hr] or more, more preferably 40 [g / m ² · a]
tm.24 hr] or more.

In the oxygen-permeable composite thin film having an oxygen-permeable homogeneous thin film layer, the oxygen-permeable homogeneous thin film layer is preferably a pinholeless homogeneous layer.
The homogeneity is used as an index for the oxygen / nitrogen transmission rate ratio α (= Q
_O2 / Q _N2 ). When the specific oxygen / nitrogen transmission rate ratio of the material forming the oxygen-permeable homogeneous thin film layer is α ^* , α of the oxygen-permeable composite membrane is preferably 0.5α ^{* to} 2.0α ^* , Preferably 0.
8α ^{* to} 1.5α ^* . When α of the oxygen-permeable composite membrane is lower than the above range, pinholes are present in the oxygen-permeable homogeneous thin film layer, which is not preferable. When α exceeds the above range, the oxygen-permeable homogeneous thin film layer is porous. The layer may be impregnated, which undesirably lowers the oxygen transmission rate of the oxygen-permeable composite membrane.

(5) Resin for embedding oxygen absorbent For example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, vinyl chloride, isoprene, butadiene, chloroprene, urethane or acrylic polymer is also used. It is possible. There is no particular limitation as long as it can hold the oxygen absorbent. However, considering oxygen permeability and water vapor permeability, silicone resin can be mentioned as the most preferable example. It is desirable that the embedding resin is packed as tightly as possible in the sense of holding the oxygen absorbent. However, if it is desired to increase the permeability of oxygen or water vapor for the purpose of improving the oxygen absorbing ability, a porous structure may be employed. The oxygen absorbent layer in which the oxygen absorbent is embedded in the silicone resin is formed by mixing the silicone compound and the oxygen absorbent, applying the mixture to a predetermined thickness on the substrate of the oxygen-permeable composite film, and then curing the mixture. It is possible. The coating method is not particularly limited, but is applied by, for example, screen printing or the like in a form suitable for the intended use. In the case of producing a laminate that is fixed to a cylindrical can, efficient production is possible by applying the laminate in a strip shape on an oxygen-permeable composite membrane sheet. Alternatively, it may be applied to the entire surface of the oxygen-permeable composite membrane sheet and cut to a required size. In addition to this, the shape of the coating can take various shapes such as a circle, an ellipse, a triangle, a square, a hexagon, and an amorphous shape according to the application. The thickness of the coating can not be determined unequivocally because the required amount of oxygen absorber varies depending on the amount of oxygen inside the container, but if there is an oxygen barrier film layer,
In consideration of the adhesiveness to the oxygen barrier film layer and the hermeticity of the oxygen barrier film layer, the thickness is preferably 5 μm to 3 mm. Further, it is possible to dilute the mixture of the compound and the oxygen absorbent with a solvent to facilitate application. Solvents such as hexane, cyclohexane, freon, ether, and halogenated hydrocarbons having a low boiling point and being volatile can be suitably used in the sense of maintaining the form after coating, but are not particularly limited to these. Absent. The volume ratio between the embedding resin and the oxygen absorbent is not particularly limited, but a preferable example is an absorbent / resin = 0.2 to 2.0. However, considering the oxygen absorption capacity and the retention of the oxygen absorbent, 0.7 to 1.
3 is particularly preferred.

(6) Oxygen Absorber Known oxygen absorbers can be used as they are.
For example, ascorbic acid, ascorbate, isoascorbic acid, isoascorbate, gallic acid, gallate, tocopherol, hydroquinone, catechol, resorcin, dibutylhydroxytoluene, dibutylhydroxyanisole, pyrogallol, Rongalit, sorbose, glucose, lignin Organic oxygen absorbers such as iron powder, activated iron, ferrous oxide, iron-based oxygen absorbers such as iron salts, sulfites, thiosulfates, dithionites, bisulfites and other inorganic oxygen absorbers One or a mixture of two or more selected from an oxygen absorbent such as an absorbent, a redox resin, a polymer metal complex such as a polymer metal complex, and a zeolite or activated carbon is appropriately used according to use conditions. When the oxygen absorbent is in the form of powder, the particle size thereof is not particularly limited, but is generally preferably small in terms of increasing the surface area. The oxygen absorbent may contain other substances such as a catalyst, a water retention agent, and a hydrate to control the oxygen absorbing ability. As the oxygen absorbent, those which do not exhibit oxygen absorbing ability under a normal atmosphere (room temperature, 70% or less relative humidity) and exhibit oxygen absorbing ability near a dew point can be easily manufactured and stored in the laminate of the present invention. It has the advantage of being particularly preferred, but is not limited to this.

(7) Oxygen Barrier Film Layer The oxygen barrier film layer is a layer whose main purpose is to shield the oxygen absorber from the air and to suppress a decrease (deactivation) of the oxygen absorbing ability during storage. However, when the oxygen-absorbing laminated sheet is brought into close contact with the inner surface side of the container, it may have a function of facilitating the close contact. Regarding the former oxygen barrier property,
Generally, as an oxygen barrier packaging material, polyvinylidene chloride-coated KOP (registered trademark) / PE (K-coated polypropylene / polyethylene), KON (registered trademark) / PE
(K-coated nylon / polyethylene), KPET (registered trademark) / PE (K-coated polyester / polyethylene), EVAL (registered trademark), Saranex (registered trademark), OV (registered trademark), films such as Varilon (registered trademark) 20-25 ° C such as aluminum foil / polyethylene
Permeation rate of 1.0 [ml / m ² · hr · at
m] The following may be mentioned, but when the oxygen absorbent has low activity under low humidity or when the time from production to mounting is short, it is not always necessary to satisfy this condition. Specifically, the oxygen transmission rate at 20 to 25 ° C. is 4000 [ml
/ M ² · hr · atm] or less, but there is no particular limitation, but when an oxygen absorbent commonly called a fast-acting type is used, the oxygen permeation rate is 125 [ml / m ² · hr · a
tm] or less. The thickness of the oxygen barrier film layer is preferably 800 μm or less in consideration of the adhesion to the oxygen-permeable composite film, and is preferably 50 μm or more in consideration of the mechanical strength. In addition to the above characteristics,
Considering the oxygen barrier property, the adhesion to the back surface of the container, the ease of production, and the like, the thickness is particularly preferably 200 to 500 μm. Regarding the latter adhesiveness, it is sufficient that the latter has sufficient adhesiveness to integrally bond either the woven or nonwoven fabric layer of the oxygen-permeable composite membrane or the oxygen absorber layer and the back surface of the container. The term "adhesiveness" as used herein includes any method capable of adhering a polymer film, such as an adhesive, heating, or ultrasonic waves. However, when it is used for beverages and foods, heating and an ultrasonic method with less eluted material are suitable, but not limited thereto.

(8) Form of Laminate The laminate thus produced may be cut or punched into a shape according to the shape of the mounting portion of the container to be mounted or the shape of the container component. Since the size of the laminated body to be mounted also affects the amount of oxygen absorption, the size may be determined as needed. Furthermore, the laminated body in the present invention, the net, woven fabric, non-woven fabric, porous sheet,
It may be protected by a member such as a sponge that does not cause a problem in oxygen transmission.

[0044]

Embodiments of the present invention will be described below. The performance of the oxygen permeable composite membrane is as follows: the primary side pressure is 2 kg / cm ² , the secondary side pressure is 1 kg / cm ² , and the gas (oxygen or nitrogen) permeation rate is a precision membrane flow meter across the composite membrane. S
It was measured by F-101 (manufactured by Standard Technology). The oxygen transmission rate Q _O2 is expressed in units of [m ³ / m ² ·
[hr · atm] and used as an index of gas permeability of the oxygen-permeable composite membrane. The oxygen / nitrogen transmission rate ratio α of the oxygen-permeable composite membrane was calculated from Q _O2 / Q _N2 and used as an evaluation standard for the homogeneity of the polymer thin film layer contained in the composite membrane.
In addition, the inherent oxygen /
The nitrogen transmission speed ratio α ^* (= P _O2 / P _N2 ) and the oxygen transmission coefficient P _O2 were measured by a depressurization method at 25 ° C. using a dense film of a raw material polymer by a gas permeability measuring device manufactured by Yanagimoto Seisakusho.

Example 1 An oxygen-permeable composite membrane (A) having oxygen permeability was prepared by the following method. A 15% by weight dimethylformamide (DMF) solution of polysulfone (Udel-P3500 manufactured by Union Carbide Co., Ltd.) was coated on a polyester nonwoven fabric (MF110 manufactured by Nippon Vilene Co., Ltd.) having a thickness of 50 μm and a basis weight of 100 g / m ² at room temperature. The polysulfone is coagulated by casting and dipping in a coagulation bath filled with water to form a membrane (I) comprising a 200 μm thick polysulfone porous layer (75% porosity) / polyester nonwoven fabric (130 μm thickness). Obtained. 0.2% by weight silanol polydimethylsiloxane at both ends (number average molecular weight 30,000 to 50,000),
A 0.1% by weight solution of tetrakis (2-propanone oxime) silane in trichlorotrifluoroethane was coated on the drained membrane (I) only at 130 ° C.
After drying by heating for 2 seconds, drying was performed at 100 ° C. for 10 minutes to obtain an oxygen-permeable composite membrane (A) composed of a crosslinked siloxane homogeneous thin film layer (thickness: about 0.1 μm) / polysulfone porous layer / polyester nonwoven fabric. The oxygen transmission rate Q _O2 of this oxygen permeable composite membrane is 6 [m ³ / m ² · hr · atm], the oxygen / nitrogen transmission rate ratio α (= Q _O2 / Q _N2 ) is 2.0, and the water vapor transmission rate is 15 [m ³ / m ² · hr · atm]. The specific oxygen / nitrogen transmission rate ratio α ^* of the crosslinked siloxane forming the thin film layer is 2.0 (the oxygen transmission coefficient P _O2 is 5 × 10 ^−8).
cm ³ · cm / cm ² · sec · cmHg), and it was confirmed that a uniform thin film layer having no defect was formed.

Under a nitrogen stream, an iron-based oxygen absorbent (Ageless (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used as an oxygen absorbent.
FX type inclusions (2.5 g), and one-component curing type RTV silicone (KE44 manufactured by Shin-Etsu Chemical Co., Ltd.)
After adding 2.0 g to cyclohexane and mixing well,
The mixture was applied to the surface of the polyester nonwoven fabric of the oxygen-permeable composite membrane (A) at a rate of 0.07 g / cm ² and dried. On top of this, a stretched polypropylene / evar / polyethylene (20/17) was used as an oxygen barrier film layer.
/ 60 μm) The sheet was heat-pressed at 140 ° C. for 10 minutes on the side of the surface coated with the oxygen absorbent to be fixed. As shown in FIG. 1, the laminated sheet obtained in this manner was, from the inside of the container, an asymmetric porous layer 8 composed of an oxygen-permeable homogeneous thin film layer 5, a dense layer 6 and a porous layer 7, a polyester Support layer 9 made of non-woven fabric, oxygen absorber layer 1 in which oxygen absorbent is embedded
0, having a laminated structure of the oxygen barrier film layer 11.
As shown in FIG. 2, this oxygen-absorbing laminate sheet 3 is
After being fixed inside a polypropylene container (1000 ml) 2 as a container body having a cap 1, 800 ml of salad oil 4 as a content was placed and stoppered. No change in quality was observed even after storage for 6 months at normal temperature and normal pressure.

Example 2 In Example 1, as an iron-based oxygen absorbent, Ageless (registered trademark) S type manufactured by Mitsubishi Gas Chemical Company, Inc.
An experiment was conducted in the same manner as described above except that 5 g) was used. As a result, no change in the quality of the salad oil was observed even after storage for 6 months.

Example 3 Polysulfone (Udel- manufactured by Union Carbide Co., Ltd.)
P3500) 15% by weight dimethylformamide (DM
F) Non-woven fabric made of polyester fiber at room temperature with a thickness of 50 μm (MF-11, manufactured by Japan Vilene Co., Ltd.)
0) Cast on top and immerse in a coagulation bath filled with water to coagulate the polysulfone, and a membrane composed of a polysulfone porous layer (porosity: 75%) with a thickness of 160 μm / polyester nonwoven fabric (thickness: 130 μm) (II) was obtained.
An amino-modified polydimethylsiloxane having the structure shown below was dissolved in trichlorotrifluoroethane to prepare a 2% by weight polymer solution.

[0049]

Embedded image

Separately, a 1% by weight solution of tolylene diisocyanate / dibutyltin diacetate [= 9/1 (weight ratio)] in trichlorotrifluoroethane was prepared. After mixing the two liquids at a ratio of 1: 1, the mixture was further diluted with trichlorotrifluoroethane to prepare a dilute solution. A part of the diluted solution is coated on the drained membrane (II), dried by heating at 130 ° C. for 1 minute, and then dried at room temperature for 1 hour to form a crosslinked siloxane homogeneous thin film layer (thickness: about 0.08 μm). / Polysulfone porous layer /
An oxygen-permeable composite membrane (B) made of a polyester nonwoven fabric was obtained. The oxygen permeable composite membrane has an oxygen permeation rate Q _O2 of 10
[M ³ / m ² · hr · atm], the oxygen / nitrogen transmission rate ratio α (= Q _O2 / Q _N2 ) is 2.1, and the water vapor transmission rate is 21 [m ³ / m ² · hr · atm]. Met. The specific oxygen / nitrogen transmission rate ratio α ^* of the crosslinked siloxane forming the thin film layer is 2.1 (the oxygen transmission coefficient P _O2 is 6 × 10 −8 c
m ³ · cm / cm ² · sec · cmHg), and it was confirmed that a uniform thin film layer having no defect was formed.

Except for using the oxygen-permeable composite membrane (B),
A container using the laminate of the present invention was prepared and evaluated in the same manner as in Example 1, and no deterioration in the quality of the salad oil was observed even after storage for 6 months.

Example 4 Poly (4-methylpentene-1) (TPX manufactured by Mitsui Petrochemical Industry Co., Ltd.) was added to 250 g of anhydrous xylene under a nitrogen atmosphere.
RMX-001) was heated and dissolved in 25 g, and 50 g of trimethoxyvinylsilane was added. Then, 1.25 g of benzoyl peroxide was added, followed by a reaction at 110 ° C. for about 4 hours. After purifying the obtained polymer by repeating reprecipitation twice from methanol, vacuum drying is performed and methoxysilane graft poly (4-methylpentene-1) is obtained.
I got The silicon content of this graft polymer is between 0.
13%. 1 g of the synthesized methoxysilane-grafted poly (4-methylpentene-1) and di-n-laurate
-Butyltin (10 mg) was dissolved in 200 g of cyclohexane. This solution was prepared using the membrane (I) prepared in Example 3.
I) Coating on top, drying by heating at 140 ° C. for 5 minutes, drying at room temperature for 1 hour, cross-linked poly (4-methylpentene-1) homogeneous thin film layer (thickness: about 0.1 μm) / polysulfone porous layer / Oxygen-permeable composite membrane (C) composed of polyester nonwoven fabric was obtained. The oxygen transmission rate Q _O2 of this oxygen permeable composite membrane is 0.2 [m ³ / m ² · hr · atm], and the oxygen / nitrogen transmission rate ratio α (= Q _O2 / Q _N2 ) is 3.
8. The water vapor transmission rate is 5 [m ³ / m ² · hr · atm]
Met. The specific oxygen / nitrogen transmission rate ratio α ^* of the crosslinked siloxane forming the thin film layer is 4.2 (the oxygen transmission coefficient P _O2 is 1.5 × 10 ⁻⁹ cm ³ · cm / cm ² · sec ·
cmHg), and it was confirmed that a uniform thin film layer having no defect was formed.

Except for using the oxygen-permeable composite membrane (C),
When a container using the laminate of the present invention was prepared and evaluated in the same manner as in Example 1, no deterioration in the quality of the salad oil was observed even after storage for 6 months.

Example 5 The oxygen-absorbing laminate sheet obtained in Example 1 was fixed to a cap of a polyethylene container (500 ml) and the inside of the container, and then 450 ml of tetrahydrofuran as a solvent was used.
And closed the cap. No peroxide formation was observed even after storage for 6 months under normal temperature and normal pressure conditions.

Example 6 The same experiment as in Example 5 was conducted except that Ageless S type (2.5 g inclusion) manufactured by Mitsubishi Gas Chemical Company, Ltd. was used as the iron-based oxygen absorbent. No product formation was observed.

Example 7 Evaluation was carried out using the same method as in Example 5 except that the oxygen-permeable composite membrane (B) obtained in Example 3 was used. As a result, no peroxide was found. .

Example 8 Evaluation was performed using the same method as in Example 5 except that the oxygen-permeable composite membrane (C) obtained in Example 4 was used. As a result, no peroxide was found. .

Example 9 When stored in the same manner as in Example 5 except that the container was a glass container and the oxygen-absorbing laminate was attached to the cap, no peroxide formation was observed.

Example 10 The oxygen-absorbing laminate sheet obtained in Example 1 was fixed to the inner side of the container body of a bottle (500 ml) made of polyethylene resin, 450 ml of oolong tea was inserted as a content, and the cap was closed. The required characteristics are as follows: 3 days after filling the beverage in the bottle, the oxygen content in the
The content was reduced to within 00 ppm, and the amount was only within 1500 ppm even after 3 months. " I was not able to admit.

Example 11 The same experiment as in Example 10 was conducted except that Ageless S type (2.5 g inclusion) manufactured by Mitsubishi Gas Chemical Company, Ltd. was used as the iron-based oxygen absorbent. The characteristics were sufficiently cleared, and the taste of oolong tea did not decrease even after 3 months.

Example 12 Evaluation was carried out in the same manner as in Example 10 except that the oxygen-permeable composite membrane (B) obtained in Example 3 was used. No decrease in the taste of oolong tea was observed.

Example 13 An evaluation was performed using the same method as in Example 10 except that the oxygen-permeable composite membrane (C) obtained in Example 4 was used. Even after 3 months, no decrease in the taste of oolong tea was observed.

[0063]

The container using the oxygen-absorbing laminate of the present invention has the following effects in preservation of those that are deteriorated or deteriorated by oxygen. (1) Since an oxygen absorber having a high oxygen absorption rate and capable of keeping the activity of the oxygen absorbent sufficiently high until the time of mounting is used, the container has a high quality maintaining ability of the contents of the container. (2) Sufficient shielding effect against liquids etc. can be exhibited while ensuring high oxygen permeation performance, so there is no permeation of liquids etc. into the oxygen absorber, and long-term use is possible even when applied to liquids and water-containing substances. It is. (3) Since there is no permeation of a liquid or the like into the oxygen absorber, phenomena such as a chemical reaction and generation of an unusual odor due to the reaction between the oxygen absorbent and the liquid do not occur. (4) Since it can be configured as a laminate of at least an oxygen absorber layer in which an oxygen absorbent is embedded in a resin and an oxygen permeable layer having an asymmetric porous layer, the production is easy, and the laminated sheet is formed. Since the formed product can be cut to any size according to the application, miniaturization is easy,
No special installation space is required. (5) If an oxygen barrier film layer is provided, even in the case of a resin container, intrusion of oxygen from the outside of the container can be more reliably suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an oxygen-absorbing laminate sheet obtained in Example 1.

FIG. 2 is a cross-sectional view of the container obtained in Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Container main body 3 Laminate 4 Contents (salad oil) 5 Oxygen-permeable homogeneous thin film layer 6 Dense thin film layer 7 Porous layer 8 Asymmetric porous layer 9 Support layer 10 Oxygen absorber layer 11 Oxygen barrier film layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-35574 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B65D 81/26 B32B 27/18

Claims (5)

(57) [Claims] At least a part of an inner surface side of a container body is
An oxygen absorber having an oxygen absorber layer in which an oxygen absorbent is embedded in a resin, and an asymmetric porous layer in which a dense thin film layer is formed on the inner side of the container with respect to the oxygen absorber layer and on the inner side of the container in the thickness direction. A container comprising a laminate including a permeable layer. 2. The container according to claim 1, wherein the oxygen-permeable layer comprises the asymmetric porous layer and a support layer that supports the asymmetric porous layer and is made of one of a woven fabric and a nonwoven fabric. 3. The container according to claim 1, wherein the laminate further includes an oxygen-permeable homogeneous thin film layer on the inside of the container with respect to the oxygen-permeable layer. 4. The container according to claim 1, wherein the laminate further has an enzyme barrier film layer on the inside of the container opposite to the oxygen absorber layer. 5. The container according to claim 1, wherein the container body is made of a resin.
5. The container according to any one of items 4 to 4.