JP2023164488A - packaging bag - Google Patents

Abstract

To provide a packaging bag which has a metal-based chemical absorbent, and of which embrittlement under high temperature environment is suppressed.SOLUTION: Packaging bags 100a, 100b are packaging bags with gas absorption property, having contents 20 and each of gas absorption films 10a, 10b, respectively. The gas absorption films 10a, 10b have absorption layer 12a, 12b, respectively, the gas absorption films 10a, 10b constitute at least a part of the packaging bags 100a, 100b, respectively, and/or are encapsulated in the packaging bags 100a, 100b, the gas absorption layers 12a, 12b contain polypropylene and a metal-based chemical absorbent, and an oxygen concentration in ambiance inside the bags is lower than an oxygen concentration in atmosphere.SELECTED DRAWING: Figure 1

Description

The present invention relates to packaging bags.

BACKGROUND ART Conventionally, in the fields of foods, pharmaceuticals, electronic components, precision instruments, recording materials, etc., a method has been adopted in which gas absorbents are included in packaging for the purpose of preventing quality deterioration. Furthermore, in order to provide the packaging material itself with a gas absorption function without including a separate gas absorbent in the package, an absorbent is included in the packaging material itself.

Specifically, as a packaging material that absorbs oxygen, Patent Document 1 describes a polyolefin inner surface material, an oxygen absorption layer made of a composition of polyolefin and an iron-based oxygen absorbent, a polyolefin buffer layer, aluminum foil, a stretched film, or an inorganic An oxygen-absorbing packaging material is disclosed which is characterized in that vapor-deposited plastic films are laminated in sequence.

Furthermore, as a packaging material that absorbs sulfide-based gases such as hydrogen sulfide and mercaptan, Patent Document 2 discloses a packaging material that includes a first skin layer containing an olefin-based elastomer, and an inorganic adsorbent and a binder that adsorbs sulfide. A laminate for adsorbing sulfide-based gases having an adsorption layer is disclosed.

As mentioned in Patent Document 2, inorganic adsorbents for adsorbing sulfides include metal-based chemical absorbents such as copper, iron, zinc, manganese, cobalt, nickel, zirconium, and lanthanide elements. It is known to use compounds or salts containing at least one selected metal.

Japanese Patent Application Publication No. 2000-343661 Japanese Patent Application Publication No. 2016-112510

Depending on the use of the packaging material, in addition to gas absorption, it may be required to have heat resistance that allows it to maintain its shape for a long period of time in high-temperature environments. In this case, it is preferable to use a polypropylene resin that is easy to form into a film and has excellent heat resistance. However, if a gas-absorbing film is made using polypropylene-based resin and metal-based chemical absorbent and placed in a high-temperature environment, the gas-absorbing film becomes brittle in a short period of time, and the heat resistance of polypropylene cannot be fully utilized. The present inventors have found that there is.

Therefore, there is a need to provide a packaging bag that has a metal-based chemical absorbent and is inhibited from becoming brittle in a high-temperature environment.

After intensive study, the present inventors found that the above-mentioned problem could be solved by the following means, and completed the present invention. That is, the present invention is as follows:
<Aspect 1> A gas-absorbing packaging bag having contents and a gas-absorbing film,
The gas absorption film includes a gas absorption layer,
The gas absorbing film is encapsulated inside the packaging bag and/or constitutes at least a part of the packaging bag,
The gas absorption layer contains polypropylene and a metal-based chemical absorbent, and the oxygen concentration in the atmosphere within the bag is lower than the oxygen concentration in the air atmosphere.
packaging bag.
<Aspect 2> According to aspect 1, the metal-based chemical absorbent contains at least one selected from the group consisting of copper, cobalt, manganese, iron, nickel, zinc, silver, calcium, and titanium. packaging bag.
<Aspect 3> The packaging bag according to aspect 1 or 2, wherein the oxygen concentration in the atmosphere within the bag is 10 mol% or less.
<Aspect 4> The packaging bag according to any one of aspects 1 to 3, wherein the content is an electronic member.
<Aspect 5> Any one of aspects 1 to 4, wherein the gas-absorbing film constitutes at least a part of the packaging bag, and has a base layer on the outside side of the gas-absorbing layer. Packaging bags listed in section.
<Aspect 6> The packaging bag according to any one of aspects 1 to 5, which is used in an environment where temperatures can reach 50° C. or higher.
<Aspect 7> The packaging bag according to any one of aspects 1 to 6, further comprising an oxygen-absorbing film sealed inside the packaging bag.

According to the present invention, it is possible to provide a packaging bag that includes a metal-based chemical absorbent and is inhibited from becoming brittle in a high-temperature environment.

FIG. 1 is a side sectional view showing one embodiment of the packaging bag of the present invention. FIG. 2 is a side sectional view showing one embodiment of the packaging bag of the present invention.

《Packaging bag》
As shown in FIG. 1, the packaging bags 100a and 100b of the present invention are gas-absorbing packaging bags that have contents 20 and gas-absorbing films 10a and 10b, and include:
The gas absorption films 10a and 10b include gas absorption layers 12a and 12b,
The gas absorption films 10a, 10b constitute at least a part of the packaging bags 100a, 100b, and/or are sealed inside the packaging bags 100a, 100b,
The gas absorption layers 12a and 12b contain polypropylene and a metal-based chemical absorbent, and the oxygen concentration in the atmosphere inside the bag is lower than the oxygen concentration in the air atmosphere.

The present inventors have discovered that embrittlement of the film is promoted by placing the polypropylene resin and the metal chemical absorbent in contact with each other in a high temperature environment in the presence of oxygen. Without wishing to be bound by theory, it is believed that this is because the reaction between the easily oxidized polypropylene resin and oxygen is accelerated by the metal-based chemical absorbent acting as a catalyst and by the high temperature environment. It will be done. In response to this problem, the present inventors have found that the above structure can suppress the embrittlement of the film by reducing the oxygen concentration, which causes the embrittlement of the polypropylene resin.

Therefore, the gas-absorbing film of the present invention can be used at high temperatures, such as 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, or 90°C or higher, and 150°C or lower, 140°C or lower, 130°C or lower, or 120°C or lower. , or in an environment where temperatures can reach 110° C. or lower. The gas-absorbing film of the invention can therefore be used, for example, for the packaging of all-solid-state lithium ion batteries.

In one aspect of the present invention, as shown in FIG. 1(a), a gas absorbing film 10a constitutes at least a portion of a packaging bag 100a. In this embodiment, as shown in FIG. 1(a), the gas-absorbing film 10a may constitute the entire packaging bag 100a, or, although not shown, the gas-absorbing film may constitute part of the packaging bag. , and other films may make up the rest of the packaging bag.

In one aspect of the present invention, as shown in FIG. 1(b), a gas absorbing film 10b is sealed inside a packaging bag 100b. In this case, the packaging bag 100b may be made of another film 30.

In one aspect of the present invention, as shown in FIGS. 2(a) and 2(b), the packaging bags 100c and 100d of the present invention further include an oxygen absorbing film 40 sealed inside the packaging bags 100c and 100d. have

The oxygen concentration in the atmosphere within the bag may be 20 mol% or less, 15 mol% or less, 10 mol% or less, 8 mol% or less, 7 mol% or less, 6 mol% or less, or 5 mol% or less, and more than 0 mol%, 1 mol%. The content may be 2 mol% or more, or 3 mol% or more. The above oxygen concentration can be obtained, for example, by enclosing an oxygen-absorbing film in a packaging bag and/or by replacing the inside of the packaging bag with nitrogen.

Each component of the present invention will be explained below.

<Contents>
The contents are not limited as long as they can deteriorate due to contact with the outside air, and include drugs, foods, cosmetics, medical instruments, medical equipment, electronic parts, precision instruments, recording materials, etc. I can do it. In addition, the drugs include detergents, agricultural chemicals, etc. in addition to pharmaceutical preparations.

Among these, when the contents are electronic components, especially all-solid lithium ion batteries that use sulfide-based solid electrolytes, heat resistance that can withstand heat generation during use and hydrogen sulfide generated by sulfide-based solid electrolytes are required. , the packaging bag of the present invention becomes more useful.

<Gas absorption film>
As shown in FIG. 1, the gas absorption films 10a and 10b include at least a gas absorption layer. As shown in FIG. 1(a), especially when the gas-absorbing film 10a constitutes at least a part of the packaging bag 100a, the gas-absorbing film 10a is based on the outer side of the gas-absorbing layer 12a. It may have a material layer 14. Further, the base layer may include a barrier layer 142 and a base resin layer 144.

Further, although not shown, the gas-absorbing film may have a skin layer on one or both sides of the gas-absorbing layer.

The gas-absorbing film of the present invention can absorb various gases, and in particular can be a hydrogen sulfide-absorbing film that absorbs hydrogen sulfide well.

The gas-absorbing film can be manufactured, for example, by melting and kneading the materials constituting the gas-absorbing layer as necessary, forming a film, and laminating each layer.

Melt-kneading can be carried out using, for example, a kneader, a Henschel mixer, a batch-type kneader such as a mixing roll, a continuous kneader such as a twin-screw kneader, or the like.

Film formation can be performed, for example, by an inflation method, a T-die method, a calendar method, a casting method, hot press molding, extrusion molding, injection molding, or the like.

Lamination can be performed by an extrusion lamination method such as a sand lamination method, a heat seal method, a hot press molding, or the like. Moreover, in particular, the base material layers can be laminated via an adhesive layer. As the adhesive layer, for example, a dry laminating adhesive, an anchor coat adhesive, a hot melt adhesive, a water-soluble adhesive, an emulsion adhesive, a non-solvent laminating adhesive, a thermoplastic resin for extrusion lamination, etc. can be used. .

Further, film formation and lamination may be performed simultaneously by a coextrusion method such as a coextrusion inflation method or a coextrusion T-die method.

(Gas absorption layer)
The gas absorption layer contains a polypropylene resin and a metal chemical absorbent. The metal-based chemical absorbent may be in contact with the polypropylene resin, and in particular may be dispersed in the polypropylene resin. The gas absorption layer may be a single layer or a laminate. In addition, in the case of a laminate, the gas absorption layer may have a layer made of polypropylene resin on one or both sides of the layer containing the metal-based chemical absorbent, In this case, the layer containing the metal-based chemical absorbent may be a layer in which the metal-based chemical absorbent is dispersed in the polyethylene resin mentioned below.

From the viewpoint of ensuring good absorption capacity, the content of the metal chemical absorbent in the layer containing the metal chemical absorbent in the gas absorption layer is 1% by mass based on the mass of the entire layer mentioned above. The above content is preferably 3% by mass or more, 5% by mass or more, 7% by mass or more, or 10% by mass or more, and from the viewpoint of ensuring good film formability, 70% by mass or less, 65% by mass or less, It is preferably 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less .

The thickness of the gas absorption layer is preferably 1 μm or more, 2 μm or more, 3 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more from the viewpoint of ensuring good absorption capacity, and 100 μm or less, 90 μm or more. or less, or 80 μm or less, from the viewpoint of ensuring the flexibility of the film.

(Gas absorption layer: polypropylene resin)
In this specification, a polypropylene resin is a resin containing more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of repeating units of propylene groups in the main chain of the polymer. Such polypropylene resins include polypropylene (PP) homopolymers, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, carboxylic acid-modified polypropylene, derivatives thereof, and mixtures thereof.

(Gas absorption layer: metal-based chemical absorbent)
The metal-based chemical absorbent may contain at least one selected from the group consisting of copper, cobalt, manganese, iron, nickel, zinc, silver, calcium, and titanium, and in particular, these alone or compounds, especially These salts may be, more particularly their silicates.

A particularly preferred metal-based chemical absorbent is a metal silicate containing at least one metal selected from copper, zinc, manganese, cobalt, and nickel, and more preferably an elemental composition (molar) ratio of metal to silicon: The metal/silicon ratio is in the range of 0.60 to 0.80. Such an inorganic adsorbent can be produced by reacting a metal salt with an alkali silicate. As the metal salt, an inorganic salt such as sulfuric acid, hydrochloric acid, or nitric acid, and/or an organic salt such as formic acid, acetic acid, or oxalic acid of at least one metal selected from copper, zinc, manganese, cobalt, and nickel is used. be able to. Among these, preferred metals are copper (I), copper (II), and zinc (I). The above-mentioned silicates include silicates of the formula M ₂ O・nSiO ₂・xH ₂ O (where M represents a monovalent alkali metal, n is 1 or more, and x is 0 or more). Acid-alkali salts can be given. The most preferred metal silicate is a copper(II) silicate which is a reaction product of copper(II) sulfate and sodium silicate, such as those described in JP-A-2011-104274. For example, a copper(II) silicate adsorbent available from Toagosei Co., Ltd. under the name Kesmon NS-20C can be used. In particular, when this metal-based chemical absorbent is used, hydrogen sulfide can be well absorbed as mentioned in Patent Document 2.

(skin layer)
The skin layer may be a layer present on one or both sides of the gas absorbing layer. Additionally, the skin layer may be fused to the gas absorbing layer.

The skin layer can prevent the metal-based chemical absorbent from falling off or coming into contact with the contents. Moreover, the skin layer may be a layer that does not contain a metal-based chemical absorbent.

The skin layer may be composed of polyolefin, for example. Examples of polyolefins include polyethylene resins and polypropylene resins.

In this specification, the polyethylene resin is a resin containing more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of ethylene group repeating units in the main chain of the polymer. As such polyethylene resin, polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) may be used, and ethylene and carboxyl A copolymer with an ethylene monomer having a group or an ester group may also be used.

As the polypropylene resin, the polypropylene resins mentioned in connection with the gas absorption layer can be used.

The thickness of the skin layer can be 1 μm or more, 3 μm or more, 5 μm or more, or 7 μm or more, and can be 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, or 15 μm or less.

(Base material layer)
The base material layer may have barrier properties. Moreover, the base material layer may have a barrier layer and a base resin layer.

Lamination of the base material layer and the gas-absorbing film and lamination of the following layers that can constitute the base material layer can be performed, for example, via an adhesive layer. The adhesive layer described above can be used as the adhesive layer.

(Base material layer: barrier layer)
As the barrier layer, a material that can suppress permeation of moisture, organic gas, and inorganic gas such as oxygen from the outside to the gas absorption layer can be used. Examples of the barrier layer include, but are not limited to, metal foils such as aluminum foil or aluminum alloy, inorganic vapor-deposited films such as aluminum vapor-deposited films, silica vapor-deposited films, alumina vapor-deposited films, or silica/alumina binary vapor-deposited films. Alternatively, an organic coating film such as a polyvinylidene chloride coating film or a polyvinylidene fluoride coating film can be used. In particular, from the viewpoint of achieving both barrier properties and ease of handling, it is preferable to use aluminum foil as the barrier layer.

The thickness of the barrier layer is preferably 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of ensuring strength and barrier properties, and 45 μm or less, 40 μm or less, or 35 μm or less to improve handleability. It is preferable from the viewpoint of improvement.

(Base material layer: base material resin layer)
As the base resin layer, a thermoplastic resin with excellent impact resistance, abrasion resistance, etc., such as polyolefin, vinyl polymer, polyester, polyamide, etc., may be used alone or in a multilayer combination of two or more types. I can do it. This base resin layer may be a stretched film or a non-stretched film. Further, this base resin layer may be present on one or both sides of the barrier layer. This base resin layer can protect the barrier layer.

Examples of the polyolefin include the polyolefin resins mentioned in connection with the skin layer.

Examples of vinyl polymers include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polychlorotrifluoroethylene, polytetrafluoroethylene, and polyacrylonitrile (PAN).

Examples of the polyester include polyethylene terephthalate (PET) and polybutylene terephthalate.

Examples of the polyamide include nylon such as nylon (registered trademark) 6 and nylon MXD6.

The thickness of the base resin layer is preferably 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of good protection of the barrier layer, and 55 μm or less, 50 μm or less, or 45 μm or less for ease of handling. It is preferable from the viewpoint of improving properties.

<Oxygen absorption film>
The oxygen-absorbing film is a layer having at least an oxygen-absorbing layer. Further, in order to prevent the oxygen absorbent of the oxygen absorbing layer from coming into contact with the contents, the oxygen absorbing film may further include a skin layer on one or both sides of the oxygen absorbing layer.

The oxygen-absorbing film can be manufactured by melting and kneading the materials constituting each layer of the oxygen-absorbing film, forming a film, and laminating each layer, if necessary. Melting kneading and film formation can be performed by the methods mentioned for the gas absorption layer.

Lamination can be performed by an extrusion lamination method such as a sand lamination method, a heat seal method, a hot press molding, or the like.

Further, film formation and lamination may be performed simultaneously by a coextrusion method such as a coextrusion inflation method or a coextrusion T-die method.

(oxygen absorption layer)
The oxygen absorbing layer may contain a thermoplastic resin and an oxygen absorbent dispersed in the thermoplastic resin.

From the perspective of ensuring good absorption capacity, the content of the oxygen absorbent in the oxygen absorbing layer is 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass, based on the mass of the entire oxygen absorbing layer. % or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, and has good film formability. From the viewpoint of ensuring this, it is preferably 90% by mass or less, 85% by mass or less, or 80% by mass or less.

The thickness of the oxygen absorption layer can be 10 μm or more, 20 μm or more, or 30 μm or more, and can be 300 μm or less, 200 μm or less, 100 μm or less, 80 μm or less, or 50 μm or less.

(Oxygen absorption layer: thermoplastic resin)
As the thermoplastic resin for the oxygen absorption layer, for example, polyolefin can be used. As the polyolefin, for example, the polyolefins mentioned in connection with the base resin layer can be used.

(Oxygen absorption layer: oxygen absorbent)
Examples of oxygen absorbers include metal oxides having oxygen vacancies, inorganic oxygen absorbers such as iron-based oxygen absorbers, and oxygen-absorbing metal-containing resin compositions containing metals and polyhydric phenols. It will be done.

Examples of metal oxides having oxygen deficiencies include cerium oxide having oxygen deficiencies, titanium dioxide having metal deficiencies, and the like. Among these, cerium oxide having oxygen vacancies is preferred as an absorbent from the viewpoint of oxygen absorbability.

The metal oxide having oxygen vacancies will be explained in more detail. Oxygen vacancies in metal oxides (MO ₂ ) occur when oxygen is forcibly extracted from the crystal lattice of metal oxides by reduction treatment in a strongly reducing atmosphere, as expressed by the following formula (1). This is caused by an oxygen-deficient state (MO _2-x , 0<x<2). The reduction treatment can be performed, for example, by heat treatment at a high temperature such as 1000° C. in a reducing atmosphere such as hydrogen gas.
MO ₂ +xH ₂ →MO _2-x +xH ₂ O...(1)

Then, as shown in the following formula (2), the oxygen-deficient portion reacts with oxygen, thereby exhibiting the effect as an inorganic oxygen absorbent.
MO _2-x + (x/2) O ₂ → MO ₂ ...(2)

The above value of x can be a positive number of 1.0 or less, and preferably a positive number of 0.7 or less. As shown in equation (2) above, metal oxides do not require the presence of water in the atmosphere for reaction with oxygen. Therefore, using a metal oxide having oxygen vacancies as an inorganic oxygen absorbent is particularly effective for contents that dislike moisture.

As the iron-based oxygen absorber, for example, iron powder (for example, reduced iron powder, atomized iron powder, activated iron powder, etc.), ferrous oxide, ferrous salt, etc. can be used.

(skin layer)
The skin layer may be a layer present on one or both sides of the oxygen absorbing layer. Additionally, the skin layer may be fused to the oxygen absorbing layer.

The skin layer can prevent the oxygen absorbent from falling off or coming into contact with the contents. Further, the skin layer may be a layer that does not contain an oxygen absorber.

The skin layer may be composed of polyolefin, for example. As the polyolefin, for example, the polyolefins mentioned in connection with the skin layer of the gas-absorbing film can be used.

The thickness of the skin layer can be 1 μm or more, 3 μm or more, 5 μm or more, or 7 μm or more, and can be 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, or 15 μm or less.

<Other films>
The other film constituting the packaging bag may be a film having barrier properties. Other films may have, for example, the barrier layer described above and the base resin layer described above. Moreover, other films may further have a sealant layer.

The sealant layer is selected depending on the material to be sealed, and may be, for example, polyethylene resin. These resins may be in the form of, for example, stretched or unstretched films, molten resins for extrusion lamination, paints for hot melt, and the like.

Further, as the sealant layer, a commercially available easy-peel resin or easy-peel sealant film that is not made of these resins may be used.

The present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

《Preparation of packaging bag》
<Example 1>
(Preparation of gas absorption film)
90 parts by mass of polypropylene (Novatec FL02A, Nippon Polypro Co., Ltd.) as a thermoplastic resin, 10 parts by mass of a copper (II) silicate-based adsorbent (Kesmon NS-20C, Toagosei Co., Ltd.) as a gas absorbent. was kneaded using a Banbury mixer, cut into pieces of a predetermined mass, and hot press-molded (pressing temperature: 190° C., pressure: 40 MPa, pressing time: 2 minutes) to produce a gas-absorbing film with a thickness of 100 μm.

The prepared gas absorption film was cut into 5 cm pieces, placed in an aluminum bag (ADY Co., Ltd.) cut to a volume of 50 ml, and heated with a nitrogen purging sealer to achieve the specified oxygen concentration. The packaging bag of Example 1 was prepared by sealing.

When we measured and confirmed the oxygen concentration inside the sealed bag using an oxygen measuring device (Packmaster model number RO-103S, Iijima Electronics Co., Ltd.), we found that the oxygen concentration at this point was 6.9 mol%. there were.

<Comparative Example 1 and Examples 2 to 5>
Packaging bags of Comparative Example 1 and Examples 2 to 5 were produced in the same manner as in Example 1, except that the conditions of the nitrogen purging sealer were changed so that the oxygen concentration in the bag was as shown in Table 1. In addition, in the packaging bag of Comparative Example 1, heat sealing was performed without nitrogen substitution.

<Comparative Example 2 and Examples 6 to 10>
Packaging bags of Comparative Example 2 and Examples 6 to 10 were produced in the same manner as Comparative Example 1 and Examples 1 to 5, except that the volume of the aluminum bag was changed to 250 ml.

"evaluation"
Each of the produced packaging bags was placed in an oven at 100°C and stored for 5 days. After storage, the gas absorption film was taken out from each packaging bag and evaluated as follows.

<color>
The color of the gas absorption film after storage was visually observed. The evaluation results are as follows.
A: Not discolored B: Lightly discolored C: Deeply discolored D: Very darkly discolored

<Crack>
Cracks on the surface of the gas absorbing film after storage were visually observed when the film was bent by 180°. The evaluation criteria are as follows.
A: No cracks or cracks occurred B: Slight cracks occurred C: Large cracks occurred D: Cracks occurred

The configurations and evaluation results of Examples and Comparative Examples are shown in Table 1 below.

From Table 1, in the packaging bags of Examples 1 to 10 in which the oxygen concentration inside the bag was lower than the oxygen concentration in the atmospheric atmosphere, the oxygen concentration inside the bag was 20.8 mol%, which is the oxygen concentration in the atmospheric atmosphere. It can be seen that the condition of the film after being stored at 100° C. was better than that of Comparative Examples 1 and 2. In particular, in Examples 2 to 5 and 7 to 10, in which the oxygen concentration in the bag is 10 mol% or less, and more particularly in Examples 3 to 5 and 8 to 10, in which the oxygen concentration in the bag is 6 mol% or less, the state of the film is As you can see, it was very good.

Furthermore, when comparing Example 2 and Example 10, which had the same amount of oxygen in the bag, differences were seen in both color and cracking. From this, it can be understood that the oxygen concentration contributes to the state of the film after storage at 100°C.

10a, 10b gas absorbing film 12a gas absorbing layer 14 base layer 142 barrier layer 144 base resin layer 20 contents 30 other film 40 oxygen absorbing film 100a, 100b, 100c, 100d packaging bag

Claims (7)

A gas-absorbing packaging bag having contents and a gas-absorbing film,
The gas absorption film includes a gas absorption layer,
The gas absorbing film is encapsulated inside the packaging bag and/or constitutes at least a part of the packaging bag,
The gas absorption layer contains polypropylene and a metal-based chemical absorbent, and the oxygen concentration in the atmosphere within the bag is lower than the oxygen concentration in the air atmosphere.
packaging bag. The packaging bag according to claim 1, wherein the metal-based chemical absorbent contains at least one selected from the group consisting of copper, cobalt, manganese, iron, nickel, zinc, silver, calcium, and titanium. . The packaging bag according to claim 1 or 2, wherein the oxygen concentration in the atmosphere within the bag is 10 mol% or less. The packaging bag according to any one of claims 1 to 3, wherein the contents are electronic components. According to any one of claims 1 to 4, the gas-absorbing film constitutes at least a part of the packaging bag, and has a base material layer on the outside side of the gas-absorbing layer. packaging bag. The packaging bag according to any one of claims 1 to 5, which is used in an environment where temperatures can reach 50°C or higher. The packaging bag according to any one of claims 1 to 6, further comprising an oxygen-absorbing film sealed inside the packaging bag.

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