JPH08258227A - Manufacture of oxygen absorbent vessel and the vessel obtained thereby - Google Patents

Abstract

PURPOSE: To quickly deoxidize the interior of a vesses only by housing foods or the like within the vessel at normal temperature under normal state by a method wherein the vessed is produced by thermoforming laminated sheet with the structure in two layers or more, each of which is prepared by being adjacent protective layer made of polystyrene-base resin to one side or both sides of deoxidizing layer made of polystyrene-base resin blended with iron power as deoxidizer. CONSTITUTION: Laminated sheet, out of which an oxygen absorbent vessel 1 is made, has the structure in two layers or more, each of which is prepared by being adjacent protective layer made of polystyrene-base resin to one side or both sides of deoxidizing layer, which is made of polystyrene-base resin blended with iron powder as deoxidizer so as to play a roll for absorbing the oxygen in the vessel 1. The oxygen absorbent vessel 1 is produced by forming, or concretely vacuum forming, vacuum pressure forming or the like laminated sheet under heat. The uses of the oxygen absorbent vessels 1 are somewhat different from each other due to the way of lamination. Concretely, when water-containing content 2 is housed within the oxygen absorbent vessel 1 made of laminated sheet containing no gas barrier layer, the vessel 1 is used under the state being packed in an enclosed bag 3 having gas barrier properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention eliminates the need to attach an oxygen absorber package and keeps contents such as food in a container at room temperature.
The present invention relates to a method for producing an oxygen-absorbing container capable of quickly deoxidizing the inside of the container only by storing it in a normal state, and an oxygen-absorbing container obtained by this method. The oxygen-absorbing container obtained by the method of the present invention can be suitably used in various fields including the food field and the drug field.

[0002]

2. Description of the Related Art Conventionally, a deoxidizing package in which a deoxidizing agent made of iron powder or the like is filled in a breathable sachet is stored together with the contents in a gas barrier packaging to prevent deterioration of the contents. The method is commonly practiced. However, this method could not be applied to a liquid or a viscous material containing a large amount of water from the viewpoint of hygiene and appearance.

Therefore, a container in which a deoxidizing agent-containing layer is laminated on the side surface of a gas barrier container has been proposed, but there is a problem that the oxygen absorption rate is slow and water must be previously supplied to the deoxidizing agent by boiling or the like. There are restrictions on the use,
A container that quickly absorbs oxygen in a package at room temperature and in a normal state is desired.

For example, as a container in which a deoxidizing agent-containing layer such as iron powder is laminated, a layer having an oxygen gas barrier property (gas barrier) layer is laminated on a layer in which a deoxidizing agent is mixed with a resin having oxygen gas permeability. A multilayer structure for packaging having the above structure has been proposed (see Japanese Patent Publication No. 62-1824). However, in this structure, a highly moisture-proof (low water vapor permeability) resin such as low-density polyethylene or ethylene-vinyl acetate copolymer is used for the layer in contact with the contents or the oxygen scavenger-containing layer. However, with an oxygen absorber such as iron powder that absorbs water and undergoes an oxidation reaction, the oxygen absorption rate is slow, and the oxidation of the contents during that time has been a problem.

Further, Japanese Patent Laid-Open No. 63-137838 also discloses a multilayer structure of a gas barrier layer and an oxygen absorbing layer mixed with a deoxidizer. The oxygen absorbing layer is a polyolefin resin. As in the invention described in Japanese Patent Publication No. 62-1824, the oxygen absorption rate is slow and the oxidation of the contents during that time is a problem. Is encouraged.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and there is no problem in use such as the need to previously supply water to the oxygen scavenger by boiling or the like, and It is an object of the present invention to provide an oxygen-absorbing container capable of quickly deoxidizing the inside of the container by simply storing food or the like at room temperature and in a normal state, and a method for producing the same.

[0007]

Means for Solving the Problems The present inventor has arranged a protective layer made of a polystyrene resin adjacent to one or both sides of a deoxidized layer made of a polystyrene resin mixed with iron powder as an oxygen scavenger. It was found that an oxygen-absorbing container having improved water permeability / air permeability and significantly improved oxygen absorption rate can be obtained by using the laminated sheet, and based on this finding, the present invention has been completed.

That is, according to the first aspect of the present invention, a protective layer made of a polystyrene resin is adjacent to one or both sides of a deoxidized layer made of a polystyrene resin mixed with iron powder as a deoxidizer. The present invention provides a method for producing an oxygen-absorbing container, which comprises thermoforming a laminated sheet having a structure of two or more layers.

In the present invention as set forth in claim 1, the laminated sheet used as a molding material for the oxygen-absorbing container is one or both sides of a deoxidizing layer made of polystyrene resin containing iron powder as a deoxidizing agent. In addition, it is a laminated sheet having a structure of two or more layers in which protective layers made of polystyrene resin are adjacent to each other.

As a polystyrene-based resin as a main component constituting the deoxidizing layer, high impact polystyrene (HIP) is used.
S), general-purpose polystyrene (GPPS), styrene-butadiene copolymer, styrene-maleic anhydride copolymer, and the like. In the present invention, those containing these as the main components are further polyphenylene oxide, styrene- It may be a mixture of a butadiene copolymer and an inorganic filler such as talc. It is usually desirable to use high impact polystyrene (HIPS).

The deoxidizing layer of the present invention comprises the above polystyrene resin mixed with iron powder as a deoxidizing agent, and has a role of absorbing oxygen in the container. The particle size of the iron powder is not particularly limited here, but usually the average particle size is 10 to 10.
A film having a thickness of 100 μm can be used. Its form is
Any plate shape, porous mass shape or the like can be used. Further, as the iron powder, pure iron is the main component, and other components are not particularly necessary.

The blending ratio of iron powder in the deoxidizing layer is usually 5 to 70% by weight, preferably 20 to 50% by weight, based on the polystyrene resin. If the blending ratio of the iron powder is too low, sufficient oxygen absorption cannot be obtained. On the other hand, if the blending ratio of the iron powder is too large, uneven elongation and delamination during thermoforming are likely to occur. In addition, in blending the iron powder, a method of appropriately diluting a masterbatch prepared in advance and using it is more efficient.

In the laminated sheet in the method of the present invention as defined in claim 1, a protective layer made of a polystyrene resin is adjacent to one or both sides of the deoxidizing layer as described above.
It has a structure of more than one layer. That is, the protective layer is not only provided on one side of the deoxidizing layer (in this case, it is necessary to be provided on the inside of the container, that is, on the side in contact with the contents), and is provided on both sides as well. It may have a layered structure. Examples of the polystyrene-based resin forming the protective layer may include the same polystyrene-based resins as those described for the deoxidizing layer, and the same ones used for the deoxidizing layer may be used, or Different ones may be used. This protective layer has the function of improving water permeability and air permeability to improve the oxygen absorption rate, and moreover, the iron powder mixed in the deoxidizing layer directly interacts with the food etc. contained in the container. It also has a function of preventing contact.

In the method of the present invention as set forth in claim 1, the laminated sheet used as a molding material for the oxygen-absorbing container is basically a protective layer made of polystyrene resin on one side or both sides of the deoxidizing layer. Although it has a two-layer or three-layer structure in which the two are adjacent to each other, various layers may be laminated if necessary.

For example, under the laminated sheet having the above basic structure,
One having a four-layer or five-layer structure in which polypropylene resin layers are laminated via an adhesive layer (protective layer / deoxidizing layer / (protective layer)
/ Adhesive layer / polypropylene resin layer).
Here, the adhesive constituting the adhesive layer is not particularly limited as long as it is suitable for adhering the deoxidizing layer or the protective layer and the polypropylene resin layer, for example, ethylene-vinyl acetate copolymer, styrene. Examples thereof include butadiene rubber and styrene-isoprene rubber. As the polypropylene-based resin forming the polypropylene-based resin layer, a propylene homopolymer or a propylene-ethylene copolymer containing a small amount of ethylene can be used.

When a gas barrier property or the like is required for the container, for example, a gas barrier layer and a polystyrene resin layer are sequentially laminated under the laminated sheet having the three-layer structure with an adhesive layer interposed therebetween. A layered structure (protective layer / deoxidation layer / protective layer / adhesive layer / gas barrier layer / adhesive layer / polystyrene resin layer) can also be used. In addition,
As the resin constituting the gas barrier layer, for example, ethylene-vinyl alcohol copolymer (EVOH) or the like can be used, but the resin is not limited thereto, and a laminate film with an aluminum foil or the like can be used. good.

In each layer constituting the laminated sheet (protective layer, deoxidizing layer, etc.), a lubricant, a coloring agent, an antioxidant, an ultraviolet absorber, a surfactant, a flame retardant, which are usually used, may be used, if necessary. Additives such as plasticizers and antistatic agents can be added as appropriate, but those that do not pose a safety and health problem should be selected and used.

As a method of laminating, there is a method in which each layer sheet is molded separately, and then each layer sheet is bonded by thermocompression bonding or each layer is sandwiched by an adhesive, but each layer is commonly used by using an extruder. The method of co-extruding using the die is most preferable in terms of efficiency and food hygiene. That is,
A method in which the constituent components of each layer are melt-kneaded in advance using a known Banbury mixer, a single-screw or twin-screw kneader, etc., and the resulting pellets are co-extruded using an extruder for each layer and a common die. Is preferred. Such a co-extrusion method is less likely to cause a crack during molding or a sheet to be broken, as compared with a bonding method by thermocompression bonding, and the adhesion is efficient, which is extremely preferable in terms of food hygiene. It is a thing.

The thickness of each layer of the thus obtained laminated sheet varies depending on the application of the container, and it is difficult to uniquely determine the thickness. Usually, the thickness of the protective layer after thermoforming is about 15 to 300 μm, and the thickness of the deoxidizing layer is about 15 to 300 μm.
It is about 300 μm, and the thickness of the entire container is 30
The thickness of the protective layer after thermoforming is about 50 to 200 μm, the thickness of the deoxidizing layer is about 50 to 200 μm, and the thickness of the entire container is about 100 to 700 μm.

According to the present invention described in claim 1,
The laminated sheet obtained as described above is thermoformed to produce an oxygen-absorbing container. Examples of the thermoforming method for the oxygen-absorbing container include vacuum forming and vacuum pressure forming. The molding conditions may be ordinary molding conditions. The external shape of the thermoformed product (container) is not particularly limited and may be appropriately selected depending on the method of use and application. Usually, the container is in the shape of a tray or a cup and has an open top. In the actual use, as described below, a sealed bag is used or a lid is used for sealing.

The oxygen-absorbing container obtained as described above can be used by various methods, but the usage method is slightly different depending on the stacking method. That is, in the case of a container using a laminated sheet that does not include a gas barrier layer, since it does not have a gas barrier property by itself, in actual use, a packaging material having a gas barrier property that further wraps this container, such as a bag. Is required. Conversely, when used in a method of wrapping the container with a packaging material having a gas barrier property, the container uses a laminated sheet containing no gas barrier layer. An example of such usage is shown in FIG. In the figure, reference numeral 1 is the oxygen-absorbing container of the present invention, and the content 2 containing a large amount of water is contained therein. Such an oxygen-absorbing container 1 is
Further, it is used by being wrapped in a gas-barrier sealed bag 3. In this case, the oxygen-absorbing container 1 is composed of a laminated sheet that does not contain a gas barrier layer as described above. For example, a laminated sheet composed of three layers of protective layer / deoxygenation layer / protective layer is heated. An oxygen-absorbing container obtained by molding is applicable. Such an oxygen-absorbing container 1 is used, for example, in PVDC.
Coated nylon / linear low-density polyethylene (LLDP
It may be housed in a sealed bag 3 made of a gas barrier material such as E) and sealed before use.

On the other hand, in the case of using a laminated sheet containing a gas barrier layer, it is of course possible to carry out the above-mentioned usage method, but since it has a gas barrier property itself, the purpose is to bother the gas barrier property. It is not necessary to wrap it in a wrapping material or the like. Therefore, normally, as shown in FIG. 2, after the contents 12 containing a large amount of water are stored in the oxygen-absorbing container 11 of the present invention, the lid member 1 having a gas barrier property.
It may be sealed in 4 for use. The cover material having a gas barrier property used in this case is not particularly limited as long as it has a gas barrier property, and examples thereof include a laminated film of polyethylene terephthalate / aluminum / ethylene-vinyl acetate copolymer and the like. .

The present invention according to claim 2 provides an oxygen-absorbing container obtained as described above. As described above, the outer shape of the oxygen-absorbing container is not particularly limited, and may be appropriately selected depending on the method of use and application.
Usually, the container is in the shape of a tray or a cup and has an open top.

Next, the present invention according to claim 3 is a protective layer comprising a polystyrene resin containing titanium oxide on one or both sides of a deoxidizing layer comprising a polystyrene resin containing iron powder as an oxygen scavenger. The present invention provides a method for producing an oxygen-absorbing container, which comprises thermoforming a laminated sheet having a structure of two or more layers adjacent to each other.

That is, in the present invention described in claim 3, as a component constituting the protective layer, a polystyrene resin mixed with titanium oxide is used instead of the polystyrene resin in the present invention described in claim 1. different. Thus, by using a polystyrene-based resin blended with titanium oxide as the protective layer, the black color of the iron powder used as the oxygen scavenger in the oxygen scavenger layer is hidden, and the appearance when viewed from the protective layer side. Hygiene can be improved. That is, in the present invention according to claim 3, by adding titanium oxide having a role as a light-shielding agent to polystyrene resin which is a component constituting the protective layer, while maintaining excellent oxygen absorption, a container It is possible to obtain a container which does not impair the surface color tone, has a good appearance, and is excellent in hygienic appearance. It should be noted that, if it is only for improving water permeability / air permeability and oxygen absorption rate, it can be solved to some extent by thinning the protective layer, but in this case, a black deoxidizing layer (black Iron powder layer)
Is insufficiently shielded from light, and there remains a problem in sanitary appearance.

In this case, the blending amount of titanium oxide needs to be adjusted depending on the thickness of the protective layer, and as described above, the average thickness of the protective layer after heat generation is usually 15 to 15.
The thickness is 300 μm, whereas the concentration of titanium oxide blended in the layer must be in the range of 30 to 2% by weight.

When the average thickness of the protective layer after thermoforming is less than 15 μm, the titanium oxide concentration is 30 in order to sufficiently mask the black color of the deoxidizing layer (black iron powder layer) containing the black iron powder. Although it is necessary to make the amount more than 30% by weight, a protective layer made of polystyrene resin containing titanium oxide in an amount more than 30% by weight will be cracked during thermoforming of the container. On the other hand, when the average thickness exceeds 300 μm, the water vapor permeability and the oxygen permeability become low, and the oxygen absorption rate becomes low. Further, when the titanium oxide concentration is less than 2% by weight in the average thickness of 300 μm, the black color of the deoxidizing layer (black iron powder layer) cannot be sufficiently hidden.

[0028]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Example 1 A protective layer (thickness: 200 μm) made of polystyrene resin / polystyrene type was prepared by a coextrusion device in which two single-screw extruders having a diameter of 65 mm, a collector, a feed block, and a 900 mm wide T-die were sequentially connected. Polystyrene type multi-layered sheet (total thickness 600 μm) of two types and three layers consisting of deoxidizing layer (thickness 200 μm) made of resin and iron powder / protective layer (thickness 200 μm) made of polystyrene resin.
It was created. Here, the polystyrene resin is HI
PS (made by Idemitsu Petrochemical, Idemitsu Styrol ET-60) was used for all layers, and the iron powder was made of pure iron having an average particle size of 45 μm and an apparent density of 1.31 g / cm ³ , and 2
A deoxidized layer was formed by diluting to an iron powder concentration of 30% by weight using a masterbatch of 60% by weight prepared in advance by an axial kneading extruder.

Next, the polystyrene-based multilayer sheet obtained as described above was processed into a container shape having a container surface area and a container opening area ratio of 2.0 and an opening portion having a diameter of 140 mm by a usual method. The sheet temperature was heated to about 120 ° C. for thermoforming. The container thus obtained was coated with a biaxially stretched nylon (Unilon G-100, manufactured by Idemitsu Petrochemical Co., Ltd.) film having a thickness of 15 μm and an ethylene vinyl alcohol copolymer (EVOH) (Kuraray) having a thickness of 12 μm. Manufactured by EVAL EP-F) film and a linear low-density polyethylene film with a thickness of 40 μm.
(X180 mm) was filled with a potato desoxycholate medium previously dissolved in a container at room temperature and sealed. As a method for investigating the oxygen absorption capacity of the present packaging container, the packaging gas was sampled through a rubber patch with an adhesive inside the packaging with a syringe and the oxygen gas concentration thereof was examined by a TCG gas chromatograph. The oxygen concentration of this packaging is 23 ℃
It was examined over time for 20 days. The space volume in the bag was adjusted to about 1000 ml.

As shown in Table 1, after one day at room temperature, oxygen was rapidly removed, and the oxygen concentration reached to the normal growth lower limit oxygen concentration level (0.1%) of mold in a few days. In addition, even though the medium was not sterilized, mold development was not observed even after 10 days.

[0032]

[Table 1] -: No mold colonies were found +: Mold colony confirmation

Example 2 Two single-screw extruders with a diameter of 65 mm and two single-screw extruders with a diameter of 50 mm were used.
With a co-extrusion device in which m-width T-dies were sequentially connected, a protective layer made of polystyrene resin and titanium oxide (thickness 30
(μm) / deoxygenation layer (thickness 200 μm) consisting of polystyrene resin and iron powder / adhesion layer (thickness 5 μm) / gas barrier layer (thickness 5 μm) / adhesion layer (thickness 5 μm) / layer consisting of polystyrene resin (255 μm) 4 kinds consisting of 5
Polystyrene-based multi-layered sheet (total thickness 500μ
m) was created. The same polystyrene-based resin layer and iron powder as those used in Example 1 were used. Further, titanium oxide is 190078 manufactured by Tokyo Ink, styrene-isoprene-styrene rubber (Califlex 1107 manufactured by Shell Chemical Co., Ltd.) is used as the adhesive for the adhesive layer, and EVOH (made by Kuraray, Eval is used as the resin that constitutes the gas barrier layer. T-102
B) was used respectively. The concentration of titanium oxide is 30
It was set to% by weight.

The polystyrene-based multi-layered sheet obtained as described above was oxidized in a container having an opening diameter (diameter) of 140 mm in which the ratio of the surface area of the container to the area of the container opening was 140 mm by a conventional method. The sheet was heated to about 120 ° C. with the protective layer containing titanium inside and thermoformed. The volume of this container was 720 ml, and the average thickness of the protective layer containing titanium oxide was 15 μm. next,
The container thus obtained was filled with 20 ml of water,
A polyethylene terephthalate (thickness 12 μm) / aluminum foil (thickness 7 μm) / ethylene-vinyl acetate copolymer (thickness 60 μm) laminate film was heat-sealed and stored at 24 ° C. under environmental conditions. Then, during that time, the oxygen concentration in the container was measured every day in the same manner as in Example 1. As a result, the inside of the container after thermoforming had a smooth appearance, and the black color of the deoxidizing layer (black iron powder layer) was sufficiently covered. Table 2 shows the oxygen concentration in the container.

[0035]

[Table 2]

Example 3 By using a co-extrusion device in which two single-screw extruders having a diameter of 65 mm and a collector, a feed block and a 900 mm width T-die were sequentially connected to the two single-screw extruders, a polystyrene resin and titanium oxide were used. Protective layer (thickness 600 μm) / deoxygenation layer (thickness 80 μm) made of polystyrene resin and iron powder
m) / adhesive layer (thickness 5 μm) / gas barrier layer (thickness 5)
μm) / adhesive layer (thickness 5 μm) / polystyrene-based resin layer (thickness 305 μm). The same polystyrene-based resin and iron powder as those used in Example 1 were used. As the iron powder base resin (masterbatch base resin), HIPS (Idemitsu Petrochemical, Idemitsu Styrol ET-60) was used, and 60% by weight was obtained in a twin-screw kneading extruder.
The masterbatch was dry-blended with HIPS (Idemitsu Petrochemical, Idemitsu Styrol ET-60) to increase the iron powder concentration in the polystyrene resin of the deoxidizing layer (black iron powder layer) to 15% by weight. did. The titanium oxide concentration was 2% by weight, and the same materials as in Example 2 were used for titanium oxide, the adhesive, and the gas barrier resin. The polystyrene-based multi-layered sheet thus obtained was mixed with titanium oxide in a container having an opening diameter (diameter) of 140 mm in which the area ratio of the container surface area to the container opening was 2.0 using a conventional method. With the protective layer inside, sheet temperature is about 12
It was heated to 0 ° C. and thermoformed. The container thus obtained had the same shape as in Example 2, and the average thickness of the protective layer containing titanium oxide was 300 μm.

Next, the container thus obtained was filled with 2
Filled with 0 ml of potato desoxycholate medium, polyethylene terephthalate (thickness 12 μm) / EVOH
A (thickness 12 μm) / ethylene-vinyl acetate copolymer (thickness 60 μm) laminate film was heat-sealed and stored at 24 ° C. under environmental conditions. Then, during that time, the oxygen concentration in the container was measured every day in the same manner as in Example 1. The EVOH used was Eval T-102B manufactured by Kuraray. as a result,
The appearance inside the container after thermoforming was smooth, and the black color of the deoxidizing layer (black iron powder layer) was sufficiently covered. Table 3 shows the oxygen concentration in the container and the presence or absence of mold.

[0038]

[Table 3] −: No mold colony was found +: Mold colony confirmed

As shown in Table 3, the oxygen concentration decreased to 0.1%, which is the normal oxygen concentration level for the growth of mold after 5 days, and mold generation was not observed even after 10 days.

Comparative Example 1 The same operation as in Example 1 was carried out except that polypropylene (Idemitsu Polypro E-100G) was used in place of the HIPS raw material of the sheet used in Example 1.
Idemitsu Polypro F-704N was used as the iron powder masterbatch base resin. The results are shown in Table 4.

[0041]

[Table 4] −: No mold colony was found +: Mold colony confirmed

As shown in Table 4, it was considered that the oxygen absorption capacity of the container was insufficient, exceeding the normal lower limit of growth oxygen concentration level (0.1%) of normal mold even after 10 days. Also,
Mold colonies were observed after 5 days.

Comparative Example 2 The sheet of Example 2 except that the concentration of titanium oxide in the protective layer made of polystyrene resin and titanium oxide was changed from 30% by weight to 35% by weight in the sheet prepared in Example 2. The same thing was formed into a film, and this sheet was used to form a container in the same manner as in Example 1. As a result of observing the appearance of the sheet and the container, there is a minute crack in the surface of the protective layer made of polystyrene resin and titanium oxide in the sheet, and after thermoforming, the crack at that location is enlarged,
The surface condition was similar to that of the surface of the egg, and it was judged that the product had no commercial value.

Comparative Example 3 In the sheet prepared in Example 2, the thickness of the protective layer made of polystyrene resin and titanium oxide was 30 μm to 2 μm.
A sheet having the same structure was prepared except that the thickness was changed to 5 μm. Using this sheet, a container was prepared in the same manner as in Example 1. In this case, the thickness of the protective layer after thermoforming is 12μ
It became m. As a result of observing the appearance of the obtained sheet and container, a microcrack was found on the surface of the protective layer made of polystyrene resin and titanium oxide in the sheet, and after thermoforming, the crack at that location was enlarged, and It had an appearance similar to the pattern on the surface. Therefore, it was judged that this sheet and container had no commercial properties.

Comparative Example 4 A sheet having the same structure as that of the sheet prepared in Example 3 was prepared except that the thickness of the protective layer made of polystyrene resin and titanium oxide was changed from 600 μm to 700 μm. Using this sheet, a container having the same shape was formed in the same manner as in Example 1. In this case, the thickness of the protective layer after thermoforming was 350 μm. Next, the container thus obtained was filled with 20 ml of a previously dissolved potato desoxycholate medium at room temperature, and polyethylene terephthalate (thickness 12 μm) / EVOH (thickness 12 μm) /
An ethylene-vinyl acetate copolymer (thickness 60 μm) laminated film was used for heat-sealing, and 2
It was stored under environmental conditions of 4 ° C. Then, during that time, the oxygen concentration in the container was measured every day by the same method as in Example 1, and the presence or absence of mold colonies was visually observed. As EVOH, EVAL E manufactured by Kuraray mentioned above is used.
PF was used. The results are shown in Table 5.

[0046]

[Table 5] −: No mold colony was found +: Mold colony confirmed

As shown in Table 5, when the thickness of the layer in contact with the content, that is, the protective layer after thermoforming exceeds 300 μm,
Oxygen uptake rate is significantly reduced, and 0.1% of general mold growth lower limit oxygen concentration cannot be achieved within several days,
It was found to cause mold growth.

[0048]

According to the present invention described in claim 1,
An oxygen-absorbing container that does not need to be attached with a deoxidizer package, has a high oxygen absorption rate, and can quickly deoxidize the inside of the container simply by storing food etc. in the container at room temperature and in the normal state. It can be manufactured. As described above, according to the present invention described in claim 1, since it is not necessary to attach the oxygen absorber package, it is possible to effectively prevent the deterioration of the viscous material containing a large amount of liquid or water. Further, in the present invention described in claim 1, there is no problem in use such as having to previously supply water to the oxygen scavenger by boiling or the like, and only storing the food or the like in the container at room temperature / normal condition. It is possible to quickly deoxidize the inside of the container.

Furthermore, according to the present invention as set forth in claim 3, by using a polystyrene resin containing titanium oxide as the protective layer, the black color exhibited by the iron powder used as the oxygen scavenger in the oxygen scavenging layer is obtained. It is possible to manufacture an oxygen-absorbing container in which the appearance is improved and the sanitary appearance is improved when viewed from the protective layer side. That is, according to the present invention described in claim 3, it is possible to manufacture an oxygen-absorbing container having an improved oxygen absorption rate without impairing the color tone of the container surface. The oxygen-absorbing container thus obtained does not need to be attached with an oxygen absorber packaging, has a high oxygen absorption rate, and can be quickly stored by simply storing food etc. in the container at room temperature / normal condition. Since it can be deoxidized, it can be suitably used in various fields such as the food field and the drug field.

[Brief description of drawings]

FIG. 1 shows an example of a method of using the container of the present invention.

FIG. 2 shows another example of the method of using the container of the present invention.

[Description of sign]

 1 Oxygen Absorbing Container 2 Contents 3 Sealed Bag 11 Oxygen Absorbing Container 12 Contents 14 Lid

Claims (4)

[Claims] 1. A laminated sheet having a structure of two or more layers in which a protective layer made of a polystyrene resin is adjacent to one or both sides of a deoxidized layer made of a polystyrene resin mixed with iron powder as an oxygen scavenger. A method for manufacturing an oxygen-absorbing container, comprising: 2. An oxygen-absorbing container obtained by the method according to claim 1. 3. A structure having two or more layers in which a protective layer made of a polystyrene resin mixed with titanium oxide is adjacent to one or both sides of a deoxidized layer made of a polystyrene resin mixed with iron powder as a deoxidizer. A method for manufacturing an oxygen-absorbing container, which comprises thermoforming a laminated sheet. 4. The average thickness of the protective layer made of polystyrene resin after thermoforming is 15 to 300 μm, and the concentration of titanium oxide blended in the layer is 30 to 2
The method of claim 3, wherein the method is wt%.