JP2000264360A - Oxygen-absorbing container cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen-absorbing container cover which is excellent in combination of capacities of oxygen absorption and hermetical sealing and also excellent in maintenance of aroma for contents while being easily producible. SOLUTION: For an oxygen-absorbing container cover comprising a container cover shell body 1 and an oxygen-absorbing packing 4 provided at the inside of the shell body 1, the packing 4 is made of a laminated body comprising a first sheet made up by sandwiching a composition of polyolefin and oxygen absorbent between polyolefin films and a second sheet made of a thermoplastic resin foam or a laminated body made up of the said foam and a thermoplastic resin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-absorbing container lid provided with an oxygen-absorbing packing, and more particularly to an oxygen-absorbing container having excellent combination of oxygen-absorbing performance and sealing performance. The present invention relates to a container lid excellent in flavor retention.

[0002]

2. Description of the Related Art It is well known that oxygen in a container has an important effect on the preservability of contents in food packaging and the like. In order to remove oxygen in a container, an oxygen absorber has been used for a long time, and an example of applying the oxygen absorber to a container wall is disclosed in Japanese Patent Publication No. Sho 62-1824. A layer formed by mixing an oxygen absorbent containing a reducing substance as a main component with a resin having oxygen permeability and a layer having oxygen gas barrier properties are laminated to form a multilayer structure for packaging.

As an example of applying an oxygen absorbent to a container lid,
U.S. Pat. Nos. 5,381,914 and 5,542,557 disclose "In a container lid comprising a container lid shell and a resin liner provided on the inner surface side of the shell, the resin liner is formed of a deoxidizer or the like. An upper layer portion which is made of a resin composition containing an additive and forms a panel portion inside the sealing portion, and which is made of a thermoplastic resin having cushioning and elasticity, and is interposed between the upper layer portion and the top surface of the shell. A container lid with a liner, comprising: a lower layer portion that joins the two, and a sealing portion formed integrally with the lower layer portion and formed on the outer peripheral side of the panel portion. A melt of a thermoplastic resin having cushioning property and elasticity is supplied into the lid shell, and a panel-like disc formed from a resin composition containing an additive such as an oxygen scavenger is placed on the melt. Position
The laminated body is pressed with a press mold in the container lid shell, and the panel portion is joined to the shell body top surface with the molten material, and the molten material is protruded to the outer periphery of the panel portion to form a sealed portion. A method for producing a container lid with a liner. Is described.

As an oxygen absorbent, iron-based ones have a high oxygen absorption rate and a large absorption capacity and are excellent in cost, but when iron or its compound is eluted into the contents,
Even if the amount is very small, there is a problem that the flavor retention of the contents is impaired.

[0005] In order to prevent the elution of the iron-based oxygen absorber into the contents, a resin layer containing no oxygen absorber is sandwiched between the inner and outer surfaces of the resin layer containing the iron-based oxygen absorber. Means for preventing exposure of the system oxygen absorbent are also employed. JP-A-10-114371 discloses a plastic container, but an oxygen-absorbing multilayer plastic container in which a thermoplastic resin layer containing no oxygen absorber is laminated on both sides of an oxygen-absorbing thermoplastic resin layer. Wherein the resin matrix of the oxygen absorbent-containing thermoplastic resin layer comprises a blend of a plurality of substantially incompatible thermoplastic resins or elastomers, wherein the incompatible thermoplastic resins or elastomers are heterogeneous in the resin matrix. An oxygen-absorbing multilayer plastic container characterized by being present in a distributed structure is described.

[0006]

In the case of using a resin composition containing an oxygen absorbent in the packing or liner of a container lid, the packing or liner comes into direct contact with the headspace in the container. Although it is recognized that this is an effective means, there are still difficulties in manufacturing and also problems that must be solved in terms of oxygen absorption, sealing properties and flavor retention.

[0007] The container lid with a liner mentioned as a conventional example,
Although it is satisfactory in that it has a combination of oxygen absorbing property and sealing property, in the production thereof, a disc formed from the resin composition containing an oxygen absorbent is placed on a resin melt serving as a sealing liner. , And a cumbersome operation of pressing it is required. In addition, it is not easy to position the disc in the center of the container lid, and in order to prevent the oxygen-absorbing agent-containing disc which is not preferable in terms of sealing performance from being applied to the sealing portion with the container mouth, the size of the disc is Must be considerably reduced, so that the oxygen absorption capacity tends to be reduced.

Further, as can be said about container lids using iron-based oxygen absorbers in general, the conventional oxygen-absorbing container lid has a function of preventing elution of iron used for oxygen absorption into the contents. However, if iron is eluted in the contents even in a trace amount, there is a disadvantage that the flavor retention of the contents is significantly impaired.

Accordingly, an object of the present invention is to provide an oxygen-absorbing container lid which is excellent in the combination of oxygen absorption performance and sealing performance, is excellent in flavor retention of contents, and is easy to manufacture. To provide.

[0010]

According to the present invention, there is provided an oxygen-absorbing container lid comprising a container lid shell and an oxygen-absorbing packing provided on the inner surface side of the shell, wherein the packing comprises polyolefin and A first sheet in which a composition with an oxygen absorber, particularly an iron-based oxygen absorber, is sandwiched by a thin film of polyolefin, and a foam of a thermoplastic resin or a laminate of the foam and a thin film of a thermoplastic resin. An oxygen-absorbing container lid comprising a laminate with a second sheet is provided. In the oxygen-absorbing container lid of the present invention, the positions of the first sheet and the second sheet are not particularly fixed, but the first sheet is located on the container lid shell side, and the second sheet is located on the container side. Is more preferable.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to an oxygen-absorbing container lid comprising a container lid shell and an oxygen-absorbing packing provided on the inner surface side of the shell. And a first sheet sandwiched by a thin film of polyolefin, and a laminate of a second sheet consisting of a foam of a thermoplastic resin or a laminate of the foam and a thin film of a thermoplastic resin. It is characteristic.

In FIG. 1 (side sectional view) showing an example of a container lid according to the present invention, this container lid shell (shell) 1 comprises:
For example, it is composed of a top plate 2 and a skirt portion 3 formed of a material such as a metal or a thermoplastic resin. On the inner surface side of the top plate 2, an oxygen-absorbing packing indicated by 4 as a whole is provided. In the oxygen-absorbing container lid of the present invention, as illustrated in FIG. 2, the packing 4 comprises a first sheet 7 in which a layer 5 of a composition of a polyolefin and an oxygen absorbent is sandwiched by a thin film 6 of a polyolefin, The second sheet 8 is made of a foam of a plastic resin or a laminate of the foam and a thin film of a thermoplastic resin.

In the present invention, in the layer 5 of the composition, as shown in FIG. 3, an oxygen absorbent is present as a dispersed particle phase 10 in a polyolefin continuous phase 9, and the oxygen absorption performance in this packing is as follows. Naturally, this oxygen absorbent 10 is used. The reason for using the oxygen absorbent particles 10 in the form of a composition with the polyolefin 9 is to enable the oxygen absorbent particles to be molded into a packing and to prevent the oxygen absorbent particles from falling off.

In the present invention, the oxygen absorbent-containing resin composition layer 5 is sandwiched between the polyolefin thin films 6 and 6. This sandwich structure prevents the iron-based oxygen absorbent particles of the composition layer 5 from being exposed to the outer surface, and in particular, causes a reduction in flavor due to iron exposure and iron transfer during the initial stage of packing and lid manufacturing from the manufacturing stage. It is effective to suppress.

In the present invention, the oxygen absorbent-containing resin composition layer 5 and the thin films 6, 6 sandwiching the same are made of polyolefin. Polyolefin has high oxygen permeability and excellent moisture resistance. It depends. That is, in the configuration of the first sheet, there is an advantage that oxygen in the container permeates and moves to the oxygen absorbent via the polyolefin, but direct contact between moisture and the oxygen absorbent is interrupted.

It is an important feature that the first sheet containing the above-mentioned oxygen absorbent and the second sheet provided with a thermoplastic resin foam are laminated to form a packing. That is, the resin sheet containing the oxygen absorbent particles, particularly the iron-based oxygen absorbent particles, is inevitably hardened as a whole and lacks cushioning property and flexibility. The cushioning property and flexibility required for the sealing performance with the part can be provided, and the cushioning property and flexibility can be provided without impairing the oxygen absorbing ability of the oxygen absorbent. This is presumably because in the resin foam, there is a space surrounded by fine cells, and this space contributes to oxygen permeation. This fact can be confirmed by the fact that, in Table 1 of the examples described later, the oxygen absorption performance of the foamed article was at the same level as that without the foamed article.

More importantly, the second sheet of foam provided on the first sheet containing an oxygen absorber, especially an iron-based acid absorber, is composed of oxides formed at the end of oxygen absorption,
In particular, it effectively acts to suppress the falling off of iron oxides and elution into the contents.

The volume expansion of the particles due to the reaction between the oxygen absorbent and oxygen is very large. For example, metallic iron particles react with full oxygen, three if the iron dioxide _(Fe 2 _{O 3),} the density of iron 7.86 g / cm ^3, the density of the red ferric oxide is at 5.1 g / cm ³ If present, the volume is about 1.6
Inflates to double. Therefore, in the structure in which the polyolefin thin film is simply sandwiched on the oxygen absorbent-containing resin layer, the oxide particles may break through the thin film and be exposed on the outer surface, and the oxide may fall into the contents,
Alternatively, there is a possibility that it may be eluted into the contents upon contact with the contents.

On the other hand, if the second sheet of the foam resin is formed in advance, the oxide particles are protected by the resin foam even if the oxide particles break through the thin film, and the oxides fall off. And the elution to the contents is prevented, and the flavor characteristics of the contents are not impaired.

Further, in the packing made of the above-mentioned laminate, an oxygen absorbent can be blended over the entire surface of the packing, so that there is an advantage that the oxygen absorbing performance of the packing can be maintained at a high level. Further, according to the present invention, the packing sheet manufactured in advance is sheared in the form of a disc, and this may be fitted into the container lid. This has the advantage that the manufacturing process is simple and the productivity is high. .

Hereinafter, each configuration of the present invention will be described in detail. [First Sheet] The first sheet is formed by sandwiching a composition of a polyolefin and an oxygen absorbent with a polyolefin thin film.

Polyolefin: In the present invention, the polyolefin functions not only as a resin matrix for dispersing and holding the oxygen absorbent, but also as a material surrounding the composition formed by dispersing the oxygen absorbent. As the polyolefin, a thermoplastic resin is used.
Low-, medium- or high-density polyethylene, linear low-density polyethylene (LLDPE), isotactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-
Butene-1 copolymer, ethylene-propylene-butene-
1 In addition to olefin homopolymers or copolymers such as copolymers, ethylene-vinyl acetate copolymers, ethylene-
An olefin-based resin such as a vinyl alcohol copolymer, an ion-crosslinked olefin copolymer (ionomer), or a blend thereof may be used. Among these, flexible ethylene-based polymer, low-density polyethylene, linear low-density polyethylene (LLDPE), or a mixture thereof is preferable.

Oxygen absorbent: Among the oxygen absorbents used in the present invention, as the iron-based oxygen absorbent, any iron-based oxygen absorbent conventionally used for this type of application can be used, but generally, it is a reducing agent. In addition, those substantially insoluble in water are preferable,
Suitable examples thereof include one type of reducing iron; low-iron oxides such as ferrous oxide, iron tetroxide, and reducing iron compounds such as iron carbide, silicon iron, iron carbonyl, and iron hydroxide. Alternatively, a material having a combination as a main component can be used. In addition, metal oxygen absorbers other than iron-based, for example, reducing zinc, reducing tin powder; metal lower oxides other than iron; reducing metal compound; and the like, a high molecular compound having a polyhydric phenol in the skeleton, For example, polyhydric phenol-containing phenol-aldehyde resins, ascorbic acid, tocopherol, or metal salts thereof can be used alone or in combination with the iron-based oxygen absorber as the oxygen absorber. In terms of oxygen absorption capacity, iron-based oxygen absorbents are particularly excellent. These oxygen absorbers generally have an average particle size of 100 μm or less, particularly preferably 50 μm or less.

If necessary, these oxygen absorbers may be used as hydroxides, carbonates, sulfites, thiosulfates, tertiary phosphates, secondary phosphates, organic acids of alkali metals and alkaline earth metals. They can be used in combination with salts, halides and the like. In particular, the oxygen absorbent can be used in combination with a water absorbing agent. As such a water absorbing agent, a deliquescent inorganic salt, a deliquescent organic compound, a water-soluble organic polymer, or the like is used. Examples of deliquescent substances include sodium chloride, calcium chloride, sodium iodide, potassium iodide, zinc chloride, ammonium chloride, ammonium sulfate, sodium sulfate, magnesium sulfate, disodium hydrogen phosphate, sodium diphosphate, potassium carbonate, Inorganic salts such as sodium nitrate; and organic compounds such as glucose, fructose, sweet potato, gelatin, modified casein, modified starch, tragacanth gum and the like. As the water-soluble organic polymer, an anionic or nonionic water-soluble organic polymer is used. As the anionic polymer, for example, sodium polyacrylate, or sodium polyacrylate,
Copolymer with polyacrylamide, polysodium methacrylate, sodium alginate, ammonium alginate, carboxymethyl starch, carboxymethyl cellulose, acrylamide-acrylic acid copolymer, maleic anhydride-vinyl ether copolymer, chitosan, sodium styrene sulfonate A polymer or the like is used. Examples of the nonionic polymer include polyacrylamide, polyvinyl alcohol (PVA), starch, cyanated starch, methylcellulose, ethylcellulose, hydroxyethylcellulose, veegum, gelatin, polyethylene glycol and the like.

Oxygen-absorbing composition: The iron-based oxygen absorbing agent is preferably used in a concentration of 1 to 200 parts by weight, especially 10 to 100 parts by weight, per 100 parts by weight of polyolefin. Other oxygen absorbents are also used in an amount of 10 per 100 parts by weight of polyolefin.
Although it can be used without any problem as long as the amount is 0 part by weight or less, it is desirable that the content of all oxygen absorbents is in the range of 1 to 200 parts by weight per 100 parts by weight of polyolefin.
If the content of the oxygen absorbent is lower than this range, it tends to be difficult to suppress the oxygen concentration in the container to a concentration or less suitable for the growth of microorganisms. In terms of lowering the concentration, there is no particular effect,
This may be disadvantageous in terms of molding workability and price. The method for preparing the oxygen-absorbing composition may be a conventional resin compounding method or a molding method, and is not particularly limited. Usually, the polyolefin and the oxygen absorbent particles are melted and kneaded by an extruder or the like, and the kneaded material is cut into a predetermined size by a cutter, and then provided for forming a predetermined sheet or film by a method described later. In the composition, in addition to the oxygen absorber, as other additives, a resin compounding agent known per se, for example,
Antioxidants, fillers, lubricants, plasticizers and the like can be blended according to a formulation known per se.

The thickness of the oxygen absorbing composition is from 10 to 30.
It is preferably 0 μm, especially 20 to 200 μm, in consideration of the size of the container lid.

Polyolefin thin film: As the material of the polyolefin thin film, the aforementioned polyolefin can be used. The thickness of the thin film is preferably from 10 to 100 μm, particularly preferably from 15 to 50 μm, in consideration of the size of the container lid. The thin film of polyolefin prevents direct contact between the oxygen absorbent and the contents of the container, and improves the tightness of the packing.

Production of the first sheet: The production method of the first sheet is the same as the ordinary production method of the multi-layer sheet, except that a thin film of polyolefin / composition of iron-based oxygen absorbent and polyolefin (oxygen-absorbing composition) / Polyolefin thin film 3
The multilayer sheet having a layer structure can be produced by a known means such as coextrusion, sandwich lamination, dry lamination, extrusion coating, and inflation.

[Second Sheet] The second sheet is made of a foam of a thermoplastic resin or a laminate of the foam and a thin film of a thermoplastic resin. As the foam, a foam obtained by blending a foaming agent with a thermoplastic resin and foaming by means known per se such as extrusion foaming and extrusion cross-linking foaming is used. The production of the foam is, of course, not limited to this, and a commercially available foam sheet can also be used. As the thermoplastic resin, those usually used for container lids can be used.In addition to the above-mentioned polyolefin, styrene resins such as polystyrene, styrene-butadiene copolymer, styrene-isoprene copolymer, ABS resin and the like can be used. And thermoplastic polyesters such as polyethylene phthalate and polytetramethylene terephthalate, and polycarbonates. The foam sheet is preferably made of polyethylene from the viewpoints of flexibility, cushioning properties, sanitary properties, oxygen permeability, moisture resistance and the like. In general, the expansion ratio of a foamed sheet is 1.
It is preferably in the range of 1 to 10, especially 1.5 to 5. Foams are roughly classified into two types: closed-cell type and open-cell type. For the purpose of the present invention, it is preferable to use a closed-cell type in order to prevent elution of iron.
Of course, even the open-cell type can be sufficiently used for the purpose of the present invention by laminating a thin film of a thermoplastic resin on the surface of the foam.
As the foaming agent, a foaming agent which decomposes at a temperature close to the processing temperature (softening temperature) of the thermoplastic resin used, for example, 2,2'-azobisisobutyronitrile, azodicarbonamides, or 4,4-oxygen Bisbenzenesulfonyl hydrazide or the like is used. These blowing agents are added at 0.2
It is used in amounts of up to 10% by weight. In the case of forming a foam having cushioning properties necessary for packing, it is preferable that a thermoplastic resin contains a foaming agent and, if necessary, a crosslinking agent. As such a crosslinking agent, a crosslinking agent which decomposes at a temperature near the processing temperature (softening temperature) of the resin used, for example, dicumyl peroxide, di-t-butyl peroxide, cumyl hydroperoxide, 2,5- An organic peroxide such as dimethyl-2,5-di (t-butyl peroxide) hexane-3 is used. These crosslinkers are used in amounts of 0.1 to 5% by weight per resin. The thickness of the foam is preferably 100 to 3000 μm, particularly 500 to 2000 μm, in consideration of the size of the container lid. The thickness of the thermoplastic resin thin film is 10
It is preferably from 200 to 200 μm, especially from 20 to 100 μm, in consideration of the size of the container lid.

[Packing] The packing of the present invention is obtained by laminating the above-mentioned first sheet and second sheet. As a method for laminating the first sheet and the second sheet, a known laminating method can be applied. For example,
It may be manufactured by heat lamination or lamination via an adhesive layer.

In the production of a multilayer packing, it may not be possible to obtain sufficient adhesiveness between the layers. In this case, an adhesive resin layer is interposed between the layers. Such adhesive resins include carboxylic acid, carboxylic anhydride, carboxylic acid In the main chain or side chain, from 1 to 700 milliequivalent (meq) / 100 g resin, especially from 10 to 500 meq / 10
A thermoplastic resin contained at a concentration of 0 g resin is exemplified.
Suitable examples of the adhesive resin include ethylene-acrylic acid copolymer, ion-crosslinked olefin copolymer, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, acrylic acid-grafted polyolefin, ethylene-vinyl acetate copolymer, copolymer One or a combination of two or more such as a polymerized polyester and a copolymerized polyamide. These resins are useful for lamination by coextrusion or sandwich lamination. In addition, a thermosetting adhesive resin such as an isocyanate-based or epoxy-based resin is also used for bonding and laminating the first sheet and the second sheet formed in advance.

The laminated structure of the packing is the first sheet /
Examples include a two-layer configuration of the second sheet, or a three-layer configuration of the second sheet / first sheet / second sheet,
Of course, the present invention is not limited to this laminated configuration. Using a three-layer packing of the second sheet / first sheet / second sheet, no matter which side of the packing is located on the content side,
This is extremely advantageous because the foam layer is always located on the content side.

[Container Lid Shell] Although the structure of the container lid of the present invention is as described above, the container lid shell (shell) is made of, for example, a top plate and a skirt portion formed of a material such as metal or thermoplastic resin. And consists of On the inner surface side of the top plate, the above-described multilayer oxygen-absorbing packing is provided. Metal, plastic, or a laminate thereof is used as a material constituting the container lid shell. As the metal material, a sheet-shaped or foil-shaped untreated surface steel (black plate), surface-treated steel, or light metal such as aluminum is used. As the surface-treated steel, chemical treatment such as phosphoric acid treatment and chromic acid treatment; chemical conversion treatment such as electrolytic chromic acid treatment; electrolytic plating treatment such as electrolytic tin plating, electrolytic zinc plating and electrolytic chromium plating; Plating treatment: A treatment which has been subjected to a hot-dip plating process such as a hot-dip tin plating process is exemplified. Its thickness is generally 0.15 to 0.2
It is preferably in the range of 5 mm.

The surface of these metal materials may be coated with one or two or more layers of any known protective coating and undercoat for thermal bonding of the liner. Suitable examples of protective paints are phenol-epoxy paints, epoxy-
Urea paint, epoxy-melamine paint, phenol-epoxy-vinyl paint, epoxy-vinyl paint, vinyl chloride-vinyl acetate copolymer paint, vinyl chloride-vinyl acetate-maleic anhydride copolymer paint, unsaturated polyester paint, saturated One or a combination of two or more such as polyester paints. When the protective coating itself does not have an adhesive property to the thermoplastic resin for the liner used, the coating for thermal bonding of the liner directly on the metal material or through the protective coating described above, that is, a known olefin resin thermal bonding Paint, for example, a paint in which polyethylene oxide or an acid-modified olefin resin is dispersed in a film-forming resin. These coated metal materials are crown, pill fur proof cap, score break type easy open cap with tab,
It is formed into an arbitrary container lid shape such as a screw cap, a lug cap, a twist-off cap and used.

On the other hand, as the resin container lid, a resin molded into a cap by means such as injection molding or press molding is used. Examples of the molding resin include thermoformable resins, for example, the various thermoplastic resins described above.

Particularly advantageous thermoplastic resins for the production of the container shell of the present invention are high-density polyethylene, polypropylene,
All resins conventionally used in the production of container shells, such as polyester and styrene resins, can be used.

The thermoplastic resin used for the lid of the container may be blended with a compounding agent known per se, for example, a filler, a pigment, a lubricant, a plasticizer, a heat stabilizer and the like at a compounding ratio known per se. Can be.

[Manufacture of Container Lid] The container lid of the present invention can be manufactured by fitting a disc-like packing made by shearing a laminated sheet into a disc into the above-mentioned container lid shell. In order to prevent the disc-like packing from dropping, an adhesive is supplied into the container lid shell, the multilayer packing is positioned on the adhesive, and the packing is pressed with a pressing mold in the container lid shell, and the packing is performed. Is bonded to the top surface of the shell with an adhesive, or a method in which a projection for preventing the packing from falling off is provided in the container lid shell.

[0039]

EXAMPLES The present invention will be specifically described by the following examples.
The present invention is not limited at all by the following examples.

Example 1 MI was 2.0 (190 ° C., 1
0 min. ) Was mixed with 25 parts by weight of an iron-based oxygen absorbent having an average particle size of 20 µm per 100 parts by weight of the resin. A film having a three-layer structure in which the oxygen-absorbing resin composition was used as an intermediate layer and both sides thereof were sandwiched between similar LLDPEs was produced by an inflation method. One of the LLDPEs on both sides was mixed with a titanium oxide pigment and colored white. The film composition was white LLDPE layer / oxygen absorbing intermediate layer / LLDPE layer = 30
μm / 50 μm / 20 μm. The LLDPE layer (non-colored side) of the three-layer film was laminated with a foamed polyethylene sheet having a thickness of 2 mm via an adhesive. The obtained laminated sheet was punched out in a circular shape, and a polyethylene cap was mounted inside a twist-off cap having a diameter of 53 mm such that the polyethylene sheet was on the top side of the cap to prepare a cap with packing. As a control product, a three-layer film without foamed polyethylene sheet alone was punched out in a circular shape (control product 1), and a foamed polyethylene sheet alone was punched out in a circular shape (control product 2). Created. The oxygen absorption capacity and sealing performance of these caps were evaluated by the following methods.

[Oxygen Absorbing Capacity Measurement] One circular packing was placed together with 1.0 ml of water in a gas impermeable container having an internal capacity of about 100 ml, and completely sealed. 50
C. for one week, and then the gas composition in the container was measured by gas chromatography to calculate the amount of oxygen absorbed.

[Evaluation of Sealing Performance] A coloring liquid (water, ink, alcohol) is put into a glass bottle having an internal capacity of about 150 ml up to the taste line, and the test cap is attached. Wrap hygroscopic paper around the cap and place it sideways in a 30 ° C. incubator. After leaving for 24 hours, the leakage is determined based on the presence or absence of coloring on the hygroscopic paper, and the sealing performance is evaluated.

The test results are shown in Table 1. The product of the present invention was excellent in both oxygen absorption capacity and sealing performance. on the other hand,
The control product 1 had an oxygen absorbing ability, but was inferior in sealing performance. Control product 2 had good sealing performance, but did not show any oxygen absorbing ability.

[0044]

Table 1 Oxygen absorption capacity (cc / cm ² ) Sealing performance ^* Inventive product 0.25 0/10 Control product 1 0.25 7/10 Control product 20 1/10 *: Number of leaks in 10 samples Is shown.

Example 2 An oxygen-absorbing lid according to the present invention was mounted on a glass bottle filled with tuna oil and orange jam as a content. The space (head space) in the container at this time was about 15 cc. A necessary sterilization treatment was performed for each content item, and a storage test was performed at 35 ° C. After saving,
Oxygen in the container almost disappeared in one week. One month after storage, the following sensory evaluation was performed.

[Sensory Evaluation] The color and taste of the contents were evaluated on a scale of 1 to 5. The results are shown in Table 2 below.

TABLE 2 Tsu Na orange jam color Taste Color Taste present invention product 4.9 4.5 4.8 4.6 Control product 2 3.0 3.6 3.6 3.8 The results of sensory evaluation, Example The color and taste were remarkably superior to those using the control product No. 1.

[0047]

The container lid of the present invention has a combination of oxygen absorption performance and sealing performance, and completely transfers or drops iron or elutes into the contents from the beginning of the production of the container lid to the end of oxygen absorption. And, as a result, there is an advantage that the flavor retention is also excellent. For this reason, the container lid of the present invention is particularly useful as a container lid for packaging containers for cosmetics and foods. In the container lid of the present invention, the packing having oxygen absorption performance is attached to the container lid by a simple process of cutting the multilayer sheet into a predetermined shape and fitting it into the top surface of the container lid. This is also advantageous.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of a container lid of the present invention.

FIG. 2 is an enlarged sectional view of the packing of the present invention.

FIG. 3 is an enlarged cross-sectional view showing a state where an oxygen absorbent is dispersed in a polyolefin continuous phase.

 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 3E084 AB10 BA01 CC01 CC03 DC01 DC03 HA02 HB03 HC07 HD01 JA04 4F100 AA21H AB02H AK01D AK01E AK03A AK03B AK03C AK04D AK63A AK63B AK63C BA04 BA05 BA07 BA10BBAJB10 JC00 JD14 JL10 JM02A JM02C

Claims (4)

[Claims] 1. An oxygen-absorbing container lid comprising a container lid shell and an oxygen-absorbing packing provided on the inner surface side of the shell, wherein the packing comprises a polyolefin and an oxygen-absorbing agent. An oxygen-absorbing material comprising a laminate of a first sheet sandwiched by a thin film and a second sheet comprising a foam of a thermoplastic resin or a laminate of the foam and a thin film of a thermoplastic resin. Container lid. 2. The container lid according to claim 1, wherein the polyolefin of the first sheet comprises linear low-density polyethylene. 3. The container lid according to claim 1, wherein the foam of the second sheet is a foam of an ethylene-based polymer. 4. The oxygen-absorbing container lid according to claim 1, wherein the first sheet is located on the container lid shell side, and the second sheet is located on the container side.