JP2019181897A - Oxygen absorptive film, and packing material - Google Patents

Abstract

To provide an oxygen absorptive film and a packing material capable of preventing oxidation and degradation of contained foods caused by oxygen remaining in a packing body of foods and stably performing sufficient oxygen absorbing ability.SOLUTION: An oxygen absorptive film 100 is formed by laminating at least a substrate 10, an oxygen absorptive coat layer 20, and an alkali sealant layer 30 in order, in which the alkali sealant layer 30 contains an alkaline substance. Alternatively, the oxygen absorptive film is formed by laminating a substrate 10, an oxygen absorptive coat layer 20, an intermediate layer, and an alkali sealant layer 30 in order.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oxygen-absorbing film and a packaging material having an oxygen-absorbing agent and an oxygen-absorbing resin composition that are suitably used for foods, drugs, pharmaceuticals, cosmetics, electronic parts and the like.

  In the packaging of food, the presence of oxygen in the package may oxidize, deteriorate or discolor the contents of the food. In order to solve such a problem, residual oxygen in the package is absorbed and removed by an oxygen-absorbing film or the like.

  Until now, as an oxygen-absorbing film that is safe and hygienic and has a sufficient oxygen absorption rate, a laminated structure comprising a substrate, an oxygen-absorbing coat layer using gallic acid as an oxygen-absorbing substance, and a sealant layer has been developed. An oxygen-absorbing film having been proposed has been proposed (see Patent Document 1).

  According to Patent Document 1, the oxygen-absorbing coat layer is formed of two layers of a gallic acid compounding layer and an alkali substance compounding layer, and a base material coated with the oxygen-absorbing coat layer and a sealant layer are laminated. Thus, the oxygen-absorbing substance does not bleed out on the sealant layer side, and a packaging material having an oxygen-absorbing ability by itself is provided.

JP 10-138410 A

However, when the gallic acid compounding layer and the alkali material compounding layer are provided as described above, the chemical reaction starts when gallic acid and the alkali material come into contact immediately after coating, and the oxygen absorbing ability is already present when used as a package. There was a problem of being deactivated.
In particular, when a water-soluble resin is used as a binder, gallic acid is also water-soluble, so it dissolves and comes into contact with an alkaline substance in a large surface area. Therefore, the reaction rate is increased and this tendency is further increased.

  Accordingly, an object of the present invention is to provide an oxygen-absorbing film that can stably exhibit sufficient oxygen-absorbing performance when used as a package.

In order to solve the above problems, the first invention of the present invention is:
An oxygen-absorbing film in which at least a base material, an oxygen-absorbing coat layer, and an alkali sealant layer are sequentially laminated, wherein the alkali sealant layer contains an alkali substance.

The second invention
An oxygen-absorbing film in which at least a base material, an oxygen-absorbing coat layer, an intermediate layer, and an alkali sealant layer are sequentially laminated, wherein the alkali sealant layer contains an alkali substance.

The third invention is
An oxygen-absorbing film comprising at least a base material, an oxygen-absorbing coat layer, an intermediate layer, an alkali-coating layer containing an alkali substance, and a sealant layer not containing an alkali substance.

The fourth invention is
The oxygen-absorbing film according to any one of claims 1 to 3, wherein the oxygen-absorbing coat layer contains at least a phenol compound as an oxygen-absorbing substance.

The fifth invention is
The oxygen-absorbing film according to any one of claims 1 to 4, wherein the oxygen-absorbing coat layer contains at least a phenol compound having a pyrogallol group as an oxygen-absorbing substance.

The sixth invention is
The oxygen-absorbing film according to any one of claims 1 to 5, wherein the oxygen-absorbing coat layer includes at least gallic acid, propyl gallate, or both as an oxygen-absorbing substance. is there.

The seventh invention
The addition amount of the oxygen-absorbing substance contained in the oxygen-absorbing coat layer is 20 wt% or more and 60 wt% or less with respect to the entire oxygen-absorbing coat layer. It is an oxygen absorptive film as described in above.

The eighth invention is
The alkali sealant layer or the alkali coat layer is an alkali substance such as sodium carbonate, potassium carbonate, calcium carbonate, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide, tripotassium citrate, sodium citrate, citric acid. The oxygen-absorbing property according to any one of claims 1 to 7, comprising at least one selected from calcium acid, potassium hydrogen carbonate, potassium pyrophosphate, calcined calcium, potassium phosphate, and sodium tartrate. It is a film.

The ninth invention
The amount of the alkali substance contained in the alkali sealant layer or the alkali coat layer is 10 wt% or more and 50 wt% or less with respect to the entire alkali sealant layer or the entire alkali coat layer. It is an oxygen absorptive film given in any 1 paragraph.

The tenth invention is
It is a packaging material characterized by including the oxygen absorptive film of any one of Claims 1-9.

  By adopting the above configuration, the oxygen-absorbing film of the present invention is low in cost, excellent in workability, and further contains a chemical substance with the oxygen-absorbing coat layer by containing an alkali substance in the alkali sealant layer. By proceeding gradually, a packaging material with high sustainability of the oxygen absorbing function can be provided.

It is a schematic sectional drawing which shows the oxygen absorptive film of 1st embodiment in connection with this invention. It is a schematic sectional drawing which shows the oxygen absorptive film of 2nd embodiment in connection with this invention. It is a schematic sectional drawing which shows the oxygen absorptive film of 3rd embodiment in connection with this invention.

  In FIG. 1, the schematic sectional drawing of the oxygen absorptive film of 1st embodiment in this invention is shown. An oxygen-absorbing film 100 in FIG. 1 includes a base material 10, an oxygen-absorbing coat layer 20, and an alkali sealant layer 30 containing an alkaline substance.

  In FIG. 2, the schematic sectional drawing of the oxygen absorptive film of this embodiment in 2nd embodiment of this invention is shown. The oxygen-absorbing film 200 in FIG. 2 includes a substrate 10, an oxygen-absorbing coat layer 20 and an intermediate layer 40, and an alkali sealant layer 30.

  In FIG. 3, the schematic sectional drawing of the oxygen absorptive film of this embodiment in 3rd embodiment of this invention is shown. 3 includes a base material 10, an oxygen-absorbing coat layer 20 and an intermediate layer 40, an alkali coat layer 50, and a sealant layer 60 containing no alkali substance.

  Below, the material, function, etc. of each layer shown in this invention are demonstrated.

(Base material)
As the base material 10 used in the present invention, it has excellent properties in mechanical, physical, chemical and the like, and has excellent strength, heat resistance, moisture resistance, pinhole resistance, puncture resistance and the like. Resin films or sheets can be used. Specifically, it includes a synthetic resin selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA) such as nylon (registered trademark), and polyethylene naphthalate (PEN).

  Also, a plastic film on which an inorganic substance such as silicon oxide or a metal oxide such as aluminum oxide is deposited, a plastic film coated with a gas barrier composition such as polyvinyl alcohol or vinylidene chloride, and a film having gas barrier properties such as MXD nylon Can be used.

  In particular, it is preferable that the gas barrier property is excellent, the deterioration with the passage of time is small, and when the content is used as an outer packaging material, the amount of oxygen passing through the outer packaging material is small. In addition, the film having gas barrier properties is desirably formed of a material having low permeability to the oxygen-absorbing substance. In particular, a plastic film on which an inorganic material such as silicon oxide is deposited is suitable. What laminated | stacked one or more vapor deposition layers which consist of the carbon containing silicon oxide formed by the plasma chemical vapor deposition method on the base material 10 which consists of a plastic film is also used preferably.

  The substrate 10 may be a single layer or may have a multilayer structure. Moreover, the base material 10 may have a film thickness of 10 μm or more and 50 μm or less. By having a film thickness within the above-mentioned range, good workability and handleability can be obtained. Furthermore, the base material 10 contains any additive known in the art, such as a plasticizer, an antioxidant, a colorant, a filler, an ultraviolet absorber, an antistatic agent, and an antiblocking agent, as necessary. May be.

(Oxygen-absorbing coat layer)
The oxygen-absorbing coat layer 20 includes an oxygen-absorbing substance and a coating agent. When the coating agent is an adhesive, the adhesive adheres the base material 10 and the alkali sealant layer 30 to the oxygen-absorbing coating layer 20 or supports the oxygen-absorbing substance, or the base material 10 and the intermediate layer. 40 is bonded.
Examples of adhesives that can be used include polyester adhesives, polyurethane adhesives,
And polyether adhesives, acrylic adhesives, epoxy adhesives, ethylene-vinyl acetate adhesives, vinyl chloride adhesives, silicone adhesives, rubber adhesives, and the like. An adhesive having oxygen permeability and water vapor permeability is particularly preferable in terms of increasing the amount of oxygen absorbed by the oxygen-absorbing coat layer. These adhesives may be used alone or in combination of two or more.

  As the oxygen-absorbing substance contained in the oxygen-absorbing coat layer 20, a phenol compound is preferable. Examples of the phenol compound include gallic acid, ascorbic acid, catechol, and hydroxybenzoic acid. Among them, a phenol compound having a pyrogallol group is particularly preferable because it has a large number of hydroxyl groups used for oxygen absorption. Examples of the phenol compound having a pyrogallol group that can be used include gallic acid esters such as gallic acid, propyl gallate, ethyl gallate, and octyl gallate. More preferred are gallic acid and propyl gallate. Since these are food additives and are relatively inexpensive, it is possible to provide a safe and inexpensive packaging material having an oxygen absorption function.

  Furthermore, the oxygen-absorbing coat layer 20 may contain any additive known in the art, such as a plasticizer, an antioxidant, a colorant, a filler, and an ultraviolet absorber, as necessary.

  The addition amount of the oxygen absorbent is preferably 20 wt% or more and 60 wt% or less with respect to the total mass of the oxygen-absorbing coat layer 20. Furthermore, in order to express sufficient oxygen absorption ability, it is more preferable that 30 wt% or more and 60 wt% or less are added. If it is less than 20 wt%, the amount of oxygen to be absorbed is insufficient, and if it exceeds 60 wt%, the adhesive force between the substrate 10 and the alkali sealant layer 30 or between the substrate 10 and the intermediate layer 40 is lowered.

The thickness of the oxygen-absorbing coating layer, it is preferred that the coating weight of 2 g / m ² or more 8 g / m ² or less. When it is thinner than 2 g / m ² , the oxygen absorption amount is extremely reduced. When it is thicker than 8 g / m ² , the strength of the coat layer itself is weakened.

  The reason why the oxygen-absorbing coat layer 20 contains an oxygen-absorbing substance is that gallic acids, in particular, have high oxygen-absorbing ability but deteriorate due to heat.

  It is known that the gallic acids of the oxygen-absorbing coat layer 20 exhibit oxygen absorptivity when a hydroxyl group reacts with oxygen in an environment where an alkaline substance and moisture exist. The reaction of gallic acids proceeds at pH 8 or higher.

(Alkaline sealant layer)
As the alkali sealant layer 30 containing an alkali substance, it is desirable to use a thermoplastic resin that exhibits excellent adhesion to an adherend when heated.
Specifically, films such as polyethylene (PE), ethylene-vinyl acetate copolymer, polyolefin such as unstretched polypropylene (CPP), and heat-sealable polyester can be used. Furthermore, it is preferable that the oxygen permeability is 1000 cc / m · day · atm or more in that the amount of absorbed oxygen increases.

  The alkali sealant layer 30 may have a film thickness of 20 μm or more and 200 μm or less. By having a film thickness within this range, good sealing strength and strength (characteristics, performance, etc.) of the alkali sealant layer 30 itself can be obtained.

  The alkali sealant layer 30 is optionally added in the art, such as an adhesion promoter, a plasticizer, an antioxidant, a colorant, a filler, an ultraviolet absorber, an antistatic agent, and an antiblocking agent. An agent may be contained.

Examples of the alkaline substance contained in the alkali sealant layer 30 include lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, rubidium hydroxide, beryllium hydroxide, magnesium hydroxide, strontium hydroxide, barium hydroxide, and carbonate. Examples include lithium, magnesium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium potassium carbonate, sodium carbonate, magnesium carbonate potassium, potassium phosphate, potassium hydrogen phosphate, sodium citrate, etc. From the aspect, it is preferably a food additive, and more preferably has heat resistance enough to be kneaded into a thermoplastic resin.
In particular, sodium carbonate, potassium carbonate, calcium carbonate, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide, tripotassium citrate, sodium citrate, calcium citrate, potassium hydrogen carbonate, having a pH of 8 or more alone The use of potassium pyrophosphate, calcined calcium, potassium phosphate, or sodium tartrate is more preferable because it can reduce the cost by reducing the alkaline substance to be contained.

  As a method for forming the alkali sealant layer 30, a thermoplastic resin and an alkali substance may be kneaded and formed by extrusion coating lamination by a T-die method or an inflation method. Moreover, it can implement by arbitrary techniques known in the said technique, such as bonding together a commercial item and an oxygen absorptive coat layer or an intermediate | middle layer with a dry laminate.

  The addition amount of the alkaline substance contained in the alkali sealant layer 30 is preferably 10 wt% or more and 50 wt% or less, and particularly preferably 30 wt% or more and 50 wt% or less with respect to the entire alkali sealant layer 30. If it is less than 10 wt%, it is insufficient for the oxygen absorption reaction of gallic acid to proceed. On the other hand, if it exceeds 50 wt%, foaming occurs during film formation, making it difficult to form a film.

(Middle layer)
The intermediate layer 40 is provided as a layer for allowing an oxygen-absorbing substance and an alkali substance to move to the intermediate layer and gradually cause an oxygen absorption reaction.

  As the material used for the intermediate layer 40, a material similar to the resin used for the oxygen-absorbing coat layer 20 and the alkali sealant layer 30 can be used. Accordingly, it is considered that the adhesive strength between the respective layers can be maintained, and at the same time, the oxygen-absorbing substance and the alkaline substance can easily move to the intermediate layer 40 and come into contact with each other.

  The thickness of the intermediate layer is preferably 0.1 μm or more and 20 μm or less. If the thickness is less than 0.1 μm, the adhesion strength between the oxygen-absorbing coat layer and the alkali coat layer or alkali sealant layer is low, and there is a possibility of peeling between the layers when used as a packaging material, and further the oxygen absorption reaction is fast. It goes on and loses much of the oxygen absorption function when used. Moreover, when larger than 20 micrometers, an oxygen absorptive substance and an alkali substance will become difficult to contact, and an oxygen absorptive reaction may not express at the time of use.

(Alkali coat layer)
The alkali coat layer 50 includes an alkali substance and a coating agent. When the coating agent is an adhesive, the same material as the thermoplastic resin used for the oxygen-absorbing coat layer 20 and the alkali sealant layer 30 can be used as the adhesive. As the alkaline substance, the same alkaline substance as that contained in the alkaline sealant layer 30 can be used.

The addition amount of the alkali substance contained in the alkali coat layer 50 is preferably 10 wt% or more and 50 wt% or less, particularly preferably 30 wt% or more and 50 wt% or less with respect to the entire alkali coat layer 50. If it is less than 10 wt%, it is insufficient for the oxygen absorption reaction of gallic acid to proceed. On the other hand, if it exceeds 50 wt%, the adhesive strength between the intermediate layer 40 and the sealant layer 60 is lowered. The alkali coat layer 50 may contain any additive known in the art such as an adhesion promoter, a plasticizer, an antioxidant, a colorant, a filler, and an ultraviolet absorber as necessary.

  The alkali coat layer 50 may have a film thickness of 0.1 μm or more and 20 μm or less. By having a film thickness within this range, good adhesion strength and strength of the coat layer itself can be obtained.

(First embodiment)
As shown in FIG. 1, the oxygen-absorbing film 100 according to the first embodiment of the present invention has a configuration in which an oxygen-absorbing coat layer 20 and an alkali sealant layer 30 are laminated on a base material 10. By using a water-insoluble resin for the oxygen-absorbing coat layer 20 and the alkali sealant layer 30, the water-soluble oxygen-absorbing substance and alkali substance are dispersed in a powder state in the layers. As a result, the periphery of the oxygen-absorbing substance and the alkaline substance is covered with the resin, so that the area where the oxygen-absorbing substance and the alkaline substance are in contact with each other is reduced, and it becomes difficult to react immediately after processing.

  On the other hand, by bonding the alkali sealant layer 30 containing an alkali substance to the oxygen-absorbing coat layer 20, the alkali sealant layer 30 exhibits alkalinity, and the oxygen-absorbing coat layer 20 is gradually brought into an alkaline environment. it can. As the oxygen-absorbing coat layer 20 is in an alkaline environment, the oxygen-absorbing reaction of the oxygen-absorbing substance proceeds gradually.

(Second embodiment)
Further, as shown in FIG. 2, the oxygen-absorbing film 200 according to the second embodiment of the present invention has a configuration in which an oxygen-absorbing coat layer 20, an intermediate layer 40, and an alkali sealant layer 30 are sequentially laminated on a base material 10. It is.
In this configuration, by separating the oxygen-absorbing coat layer 20 and the alkali sealant layer 30 containing an alkali substance by the intermediate layer 40 provided therebetween, the reaction immediately after processing is unlikely to occur, and the oxygen absorbing function is lost. Can suppress life. On the other hand, the oxygen absorption reaction and the alkali material are transferred to the intermediate layer 40 and come into contact with each other, so that the oxygen absorption reaction gradually develops.

(Third embodiment)
As shown in FIG. 3, the oxygen-absorbing film 300 according to the third embodiment of the present invention has an oxygen-absorbing coat layer 20, an intermediate layer 40, an alkali coat layer 50 or an alkali sealant layer 30, and a sealant on a substrate 10. In this configuration, the layers 60 are sequentially stacked. The sealant layer 60 is a sealant that does not contain an alkaline substance.
In this configuration, the oxygen-absorbing film is composed of three layers of the oxygen-absorbing coat layer 20 and the intermediate layer 40, the alkali coat layer 50 containing an alkali substance, or the alkali sealant layer 30. By separating the oxygen-absorbing coat layer 20 and the alkali coat layer 50 by the intermediate layer 40, it is possible to further suppress the deterioration of the oxygen absorption function. On the other hand, as in the second embodiment, the oxygen absorption reaction is manifested when the oxygen-absorbing material and the alkali substance move to and contact the intermediate layer 40.

  In the first to third embodiments, if the base material 10 has a barrier function and the alkali sealant layer 30 or the alkali coat layer 50 has an oxygen permeation function, dissolved oxygen in the packaging material or in the head space. The remaining oxygen and the oxygen entering from the end face of the adhesive having oxygen permeability with the passage of time are absorbed by the oxygen-absorbing coat layer 20, and the oxidative deterioration of the contents can be suppressed.

  A packaging material according to the present invention includes the above oxygen-absorbing film. Specifically, at least a part of the packaging material is formed of an oxygen-absorbing film. In addition to the oxygen-absorbing film, the packaging material of the present invention may be provided with functional layers such as a printing layer, a barrier layer, and a surface protective layer.

Application examples of the packaging material of the present embodiment include, for example, a bag, an MA packaging material, a lid material (top material), a sheet, a bag with a chuck, a cover film, and an interior cardboard. Further, the bag-shaped packaging material may be formed by heating and bonding the peripheral portions of two oxygen-absorbing films with the sealant layer 30 disposed inside. Furthermore, you may form a bag with what is called a "gusset" by interposing the 3rd film in the peripheral part which bonds together.
The bag-shaped packaging material may have any shape including a rectangle, a circle, and a triangle. Moreover, as a bag with a chuck | zipper, what provided the fitting part which can be opened and closed in the opening part of a bag-shaped packaging material by machining may be used.

  Although the example of the articles | goods packaged using the packaging material of this embodiment is not specifically limited, For example, food / beverage, cosmetics, industrial materials, a pharmaceutical, a medical device, an electronic device, and a cultural property are included.

  Hereinafter, specific examples of the present invention will be specifically described by the following examples, but the present invention is not limited thereto.

<Example 1>
A transparent vapor-deposited polyester film (GL film made by letterpress printing) having a thickness of 12 μm was used as a base material 10, and an oxygen-absorbing coating layer 20 in which 30 wt% of gallic acid as an oxygen-absorbing substance was added to a urethane coating agent was provided by 6 μm. Further, an alkali sealant layer 30 in which 30 wt% of sodium carbonate is added to a low density polyethylene resin (“LC600A” manufactured by Nippon Polyethylene) is formed on the oxygen-absorbing coat layer 20 by extrusion coating lamination with a thickness of 30 μm. An absorbent film was prepared.

(Oxygen absorption test)
Using the oxygen-absorbing film prepared above, a packaging bag having overall dimensions of 10 cm wide × 10 cm long was prepared, and 100 cc of air was injected into the bag. The oxygen concentration after storage for a certain period in a constant temperature bath at 50 ° C. was measured, and each oxygen absorption amount was confirmed from the difference from the initial oxygen concentration. When the residual oxygen amount was 10% or less, “◯” was evaluated, and when it was 10% or more, “X” was evaluated.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

<Example 2>
An oxygen-absorbing film was prepared by repeating the procedure of Example 1 except that the oxygen-absorbing substance was changed to propyl gallate.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

<Example 3>
An oxygen-absorbing coating layer 20 in which a transparent vapor-deposited polyester film having a thickness of 12 μm (GL film manufactured by letterpress printing) is used as a base material 10 and 30 wt% of gallic acid as an oxygen-absorbing substance is added to the above-mentioned base material. 6 μm. Furthermore, 5 μm of low density polyethylene resin (“LC600A” manufactured by Nippon Polyethylene) as an intermediate layer 40 is added on the oxygen-absorbing coat layer 20 and 30 w% of sodium carbonate is added to the low density polyethylene resin (“LC600A” manufactured by Nippon Polyethylene). The alkali sealant layer 30 thus formed was formed by extrusion coating lamination with a thickness of 30 μm to produce an oxygen-absorbing film.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

<Example 4>
An oxygen-absorbing coating layer 20 in which a transparent vapor-deposited polyester film (GL film made by letterpress printing) having a thickness of 12 μm is used as a base material 10 and 30 wt% of gallic acid is added as an oxygen-absorbing substance to a urethane-based coating agent. 6 μm. Further, on the oxygen-absorbing coat layer 20, 5 μm of low density polyethylene resin (“LC600A” made by Nippon Polyethylene) is used as the intermediate layer 40, and sodium carbonate is added to the low density polyethylene resin (“LC600A” made by Japan Polyethylene) by 30 wt. The low-density polyethylene film 10 μm was formed by extrusion coating lamination as the sealant layer 60 containing 30% of the alkali sealant layer 30 added with 30% and no alkali substance, thereby producing an oxygen-absorbing film.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

<Comparative Example 1>
Using 12 μm thick transparent vapor-deposited polyester film (GL film made by letterpress printing) as a base material, add 30 wt% gallic acid as an oxygen-absorbing substance and 30 wt% sodium carbonate as an alkaline substance to the urethane-based coating agent. The oxygen-absorbing coat layer thus prepared was provided at 6 μm. A low-density polyethylene film 30 μm as a sealant layer was bonded to the oxygen-absorbing coat layer 20 by dry lamination to produce an oxygen-absorbing film.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

<Comparative example 2>
Using a transparent vapor-deposited polyester film (GL film made by letterpress printing) having a thickness of 12 μm as a base material, an oxygen-absorbing coating layer of 6 μm in which 30 wt% of gallic acid as an oxygen-absorbing substance is added to the urethane-based coating agent. Provided. Furthermore, 6 μm of an alkali coating layer in which 30 wt% of sodium carbonate as an alkaline substance was added to the urethane coating agent was provided. As a sealant layer, an oxygen-absorbing film was prepared by laminating with a low-density polyethylene film 30 μm by dry lamination.
Table 1 shows the evaluation results of the obtained oxygen-absorbing film.

As shown in Table 1, in Examples 1 to 4, the reaction immediately after processing is suppressed, and the oxygen absorbing ability is expressed at the timing of using the film (such as when the contents are filled).
On the other hand, in Comparative Examples 1 and 2, the reaction occurred immediately after processing, and the oxygen absorption capacity was lost at the timing of using the film (such as when the contents were filled), and showed almost no oxygen absorption. This is probably because the oxygen absorption reaction proceeded immediately after processing in Comparative Examples 1 and 2 because the oxygen-absorbing substance and the alkaline substance were in direct contact.
From the above results, it was found that the oxygen-absorbing film of the present invention stably exhibits a sufficient oxygen-absorbing function at the timing of using the film by suppressing the reaction immediately after processing.

DESCRIPTION OF SYMBOLS 10 Base material 20 Oxygen-absorbing coat layer 30 Alkali sealant layer 40 Intermediate layer 50 Alkali coat layer 60 Sealant layer 100, 200, 300 Oxygen-absorbing film

Claims (10)

  An oxygen-absorbing film obtained by sequentially laminating at least a base material, an oxygen-absorbing coat layer, and an alkali sealant layer, wherein the alkali sealant layer contains an alkali substance.   An oxygen-absorbing film obtained by sequentially laminating at least a base material, an oxygen-absorbing coat layer, an intermediate layer, and an alkali sealant layer, wherein the alkali sealant layer contains an alkali substance.   An oxygen-absorbing film comprising at least a base material, an oxygen-absorbing coat layer, an intermediate layer, an alkali-coating layer containing an alkali substance, and a sealant layer not containing an alkali substance.   The oxygen-absorbing film according to any one of claims 1 to 3, wherein the oxygen-absorbing coat layer contains at least a phenol compound as an oxygen-absorbing substance.   The oxygen-absorbing film according to any one of claims 1 to 4, wherein the oxygen-absorbing coat layer contains at least a phenol compound having a pyrogallol group as an oxygen-absorbing substance.   The oxygen-absorbing film according to any one of claims 1 to 5, wherein the oxygen-absorbing coat layer contains at least gallic acid, propyl gallate, or both as an oxygen-absorbing substance.   The addition amount of the oxygen-absorbing substance contained in the oxygen-absorbing coat layer is 20 wt% or more and 60 wt% or less with respect to the entire oxygen-absorbing coat layer. An oxygen-absorbing film as described in 1.   The alkali sealant layer or the alkali coat layer is an alkali substance such as sodium carbonate, potassium carbonate, calcium carbonate, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide, tripotassium citrate, sodium citrate, citric acid. The oxygen-absorbing property according to any one of claims 1 to 7, comprising at least one selected from calcium acid, potassium hydrogen carbonate, potassium pyrophosphate, calcined calcium, potassium phosphate, and sodium tartrate. the film.   The amount of the alkali substance contained in the alkali sealant layer or the alkali coat layer is 10 wt% or more and 50 wt% or less with respect to the entire alkali sealant layer or the entire alkali coat layer. The oxygen-absorbing film according to any one of the above.   A packaging material comprising the oxygen-absorbing film according to claim 1.

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