JP2021183391A - Laminate, package and packaged object - Google Patents

Abstract

To provide a laminate which has suppressed influence on a formed product on absorbing oxygen for obtaining practical utility as a packaging material while maintaining sufficient oxygen absorption performance, and a package and a packaged object including the same.SOLUTION: A laminate comprises in this order an outermost layer, an oxygen absorption layer containing an oxygen absorption substance, and an innermost layer. The oxygen absorption layer comprises an oxygen absorption substance-containing layer including at least an oxygen absorption substance and a binder resin, and an alkaline substance-containing layer including at least an alkaline substance and a binder resin, wherein the main component of the binder resin included in the oxygen absorption substance-containing layer and the alkaline substance-containing layer is a water-insoluble resin having a hydroxyl group on its side chain.SELECTED DRAWING: Figure 1

Description

The present invention relates to laminates, packages and packaged articles.

In the packaging of food, the presence of oxygen in the packaging may oxidize the food, etc., which is the content, and deteriorate or discolor. In order to prevent oxidative deterioration of the packaged contents, it is effective to remove oxygen in the package and to create an oxygen-free state by blocking external oxygen from entering the package.

However, since the packaging work is generally performed in the atmosphere, oxygen remains in the packaging during packaging. In order to solve this problem, means such as degassing packaging, vacuum packaging, and gas replacement packaging may be used as means for packaging so that oxygen does not remain in the packaging.

However, if such a special packaging means is used, it is necessary to separately prepare a special filling and packaging equipment, which is disadvantageous in that a high equipment cost is required and the filling and packaging speed is not increased and the production efficiency is lowered. Occurs. Further, even if the packaging is performed by the above means so that oxygen does not remain during packaging, it is difficult to maintain the inside of the packaging in an oxygen-free state because external oxygen invades through the packaging material over time after packaging. ..

Therefore, as a method of removing residual oxygen in the package and oxygen that infiltrates from the outside over time after packaging, an oxygen scavenger consisting of a pouch filled with an oxygen absorbing substance is enclosed in the package containing the contents. The method is used. In this method, oxygen can be removed by absorbing oxygen by the oxygen absorbing substance for a certain period of time, that is, a period during which the oxygen absorbing capacity of the oxygen absorbing substance is maintained. Therefore, it is possible to remove oxygen remaining in the package during packaging and oxygen that has entered from the outside over time, which is very effective in maintaining the oxygen-free state in the package. However, when an oxygen scavenger is used, it takes time and cost to fill a pouch with an oxygen-absorbing substance or to enclose it in a package. In addition, there are problems such as the possibility of accidental ingestion by consumers and the generation of garbage.

As a means for eliminating such defects and removing and blocking oxygen in the packaging for a certain period of time, an oxygen absorbing film having an oxygen absorbing function in a part of a film constituting the packaging material or oxygen absorption using the film or the like. Packaging materials have been devised and some have been put into practical use.

Currently, oxygen-absorbing packaging materials such as those mentioned above are often used in the food packaging field, especially for packaging long-term storage foods such as retort pouch foods (high-temperature and high-pressure sterilized foods) and high-moisture foods that are prone to mold. Be done.

In particular, regarding the packaging of long-term preserved foods, the use of cans and bottles has decreased in recent years from the viewpoint of transportation costs and disposal of containers, while retort pouch packaging with an oxygen absorbing film provided as part of the packaging material. The form of the material is the mainstream.

When the container is a can or a bottle, oxygen does not enter from the outside and only the oxygen remaining at the time of packaging needs to be removed. Therefore, methods such as vacuum packaging and nitrogen gas replacement packaging have been used. When an oxygen absorbing packaging material is used instead of a can or a bottle, there is no problem of equipment cost and production efficiency due to the use of special packaging means such as vacuum packaging and nitrogen gas replacement packaging as described above. However, since the conventional oxygen absorbing film is more permeable to oxygen than the bottle / can, it is difficult to give the retort pouch packaging material the same expiration date as the can / bottle. Therefore, various oxygen absorbing films that can be suitably used as retort pouch packaging materials and oxygen absorbing packaging materials using the same have been developed.

Oxygen-absorbing packaging materials currently in practical use include those in which iron or oxygen-deficient oxide is added to a resin as an oxygen-absorbing substance, and those in which an unsaturated bond is provided in a part of the structure of the resin composition.

However, the use of iron-based oxygen absorbers limits the use of metal detectors, and there are problems that the price of the material itself is high for oxygen-deficient oxides and resin compositions having unsaturated bond structures.

On the other hand, organic substances such as ascorbic acids, reducing saccharides such as glucose, polyhydric alcohols such as glycerin, phenols such as catechol, and phenolcarboxylic acids such as hydroxybenzoic acid are used as oxygen absorbing substances for deoxidizers. It is a substance that has been studied for a long time, and its cost is low and it is safe.

For example, as an oxygen-absorbing packaging material using gallic acid (3,4,5-trihydroxybenzoic acid), which is a phenol carboxylic acid, as an oxygen-absorbing substance, Patent Document 1 describes a base film, a gallic acid-blended layer, and an oxygen-absorbing packaging material. An oxygen absorbing film in which alkaline substance-blended layers are laminated in this order is disclosed. Further, Patent Document 2 discloses an oxygen absorbing film in which a gallic acid compounding layer, an alkaline substance compounding layer and a sealing layer are laminated in this order on a base film.

Japanese Unexamined Patent Publication No. 11-79255 Japanese Unexamined Patent Publication No. 10-138410

The present inventors have conducted extensive research on an oxygen-absorbing film having an oxygen-absorbing layer containing an oxygen-absorbing substance such as gallic acid and containing an alkaline substance as an auxiliary agent. Oxygen absorption is due to the oxidation of gallic acid, and the oxidation of gallic acid requires a basic atmosphere around the gallic acid. To form a basic atmosphere, it is necessary to dissolve an alkaline substance in water. As the water vapor, water vapor that invades from the outside of the film can be used. Therefore, it was found that water was accumulated in the film as the oxidation reaction of gallic acid proceeded, and it existed as an aqueous solution containing an oxide of gallic acid and an alkaline substance. It was found that this aqueous solution flowed in the film and exuded from the edge of the film. The exuded aqueous solution moves to the vicinity of the film and pollutes the surrounding environment.

Therefore, the present invention provides a laminated body having excellent oxygen absorption performance, a package containing the same, and a packaged article, which eliminates problems caused by exudation caused by components contained in the film as an oxygen absorbing film. Make it an issue.

The laminate according to the present invention includes an outermost layer, an oxygen absorbing layer, and an innermost layer in this order, and the oxygen absorbing layer is at least an oxygen absorbing substance-containing layer containing an oxygen absorbing substance and a binder resin, and at least an alkaline substance. It is characterized by having an alkaline substance-containing layer containing a binder resin and a resin in which the main component of the binder resin contained in the oxygen absorbing substance-containing layer and the alkaline substance-containing layer is water-insoluble and has a hydroxyl group in the side chain. Is what you do.

As the main component of the water-insoluble binder resin in the laminate, a resin modified with polyvinyl alcohol having a hydroxyl group content of 20 to 40 mol% may be used.

The water-insoluble resin may be a polyvinyl acetal resin.

It is preferable that the oxygen absorbing substance is contained in a ratio of 10% by mass to 50% by mass with respect to the total mass of the oxygen absorbing substance-containing layer.

It is preferable that the alkaline substance is contained in a ratio of 20 parts by mass to 100 parts by mass with respect to 100 parts by mass of the oxygen absorbing substance.

It is preferable to contain at least a phenol compound as an oxygen absorbing substance.

It is preferable to contain at least a phenol compound having a pyrogallol group as an oxygen absorbing substance.

As the oxygen absorbing substance, it is preferable to contain at least one selected from gallic acid and gallic acid ester.

The innermost layer can be a laminated body including a sealant layer.

The laminate of the present invention can be used as a package, and can be provided as a package containing the contents contained in the package.

According to the present invention, it is possible to provide a laminated body having excellent oxygen absorption performance, a packaged body containing the same, and a packaged article, which eliminates problems caused by exudation caused by components contained in the film as an oxygen absorbing film. Therefore, it is possible to provide a packaging form that is superior in handling as compared with a packaging form such as a can or a bottle.

The cross-sectional view schematically which shows the laminated body which concerns on one Embodiment of this invention.

The laminate according to the present embodiment may be used as an oxygen absorbing film in the form of a sheet, or may be used as a packaging material in the form of, for example, a bag, for example, foods, drugs, pharmaceuticals, cosmetics, electronic parts. It is suitably used for packaging such as.

<Laminated body>
Hereinafter, the laminated body according to the present embodiment will be described with reference to the drawings.

FIG. 1 shows a typical configuration example of the laminated body according to the present embodiment.

FIG. 1 is a cross-sectional view schematically showing a laminated body 1 according to an embodiment. The laminate 1 includes an outermost layer 10, an oxygen absorbing layer 11 including an oxygen absorbing substance-containing layer 11a and an alkaline substance-containing layer 11b, and an innermost layer 12.

In the laminated body shown in FIG. 1, an adhesive layer may be provided between any one or more layers. Further, the oxygen absorbing substance-containing layer 11a and the alkaline substance-containing layer 11b in FIG. 1 may be laminated in the reverse order with respect to the base material 10.

The materials and functions of each layer will be described below.

(Outermost layer)
For the outermost layer 10, a base material having at least oxygen barrier property and water vapor barrier property is used. As shown in FIG. 1, the outermost layer 10 may be a base material having a single layer, or may be a base material having a multi-layer structure provided with an oxygen barrier layer, a water vapor barrier layer, and the like.

The base material used for the outermost layer 10 may be polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon (registered trademark)), polyethylene naphthalate, or the like. Those usually used as packaging materials such as molecular copolymers can be used. Further, it is also possible to use a resin film coated with a coating liquid such as polyvinyl alcohol, ethylene vinyl alcohol, or polyvinylidene chloride, which has a relatively high barrier property, on a plastic base material. The base material is appropriately selected from the above materials according to the application, the layer structure of the outermost layer, and the like.

In addition, in order to obtain oxygen barrier properties and water vapor barrier properties, a vapor deposition layer of inorganic compounds such as aluminum, oxides, fluorides, and nitrides may be provided on the substrate by CVD or sputtering, or aluminum foil may be bonded. , An oxygen barrier layer or a steam barrier layer may be formed by a coating agent having an oxygen barrier property or a water vapor barrier property.

The outermost layer may contain known additives such as a plasticizer, an antioxidant, a colorant, a filler, an ultraviolet absorber, an antistatic agent, and an antiblocking agent, if necessary.

The film thickness of the outermost layer 10 can be appropriately set. From the viewpoint of good processability and handleability, the film thickness may be 10 μm or more and 50 μm or less.

Further, an anchor layer for improving the adhesiveness with the oxygen absorbing layer may be formed on the outermost surface of the outermost layer 10 on the side in contact with the oxygen absorbing layer.

(Oxygen absorption layer)
The oxygen absorbing layer 11 is composed of an oxygen absorbing substance-containing layer 11a and an alkaline substance-containing layer 11b.

The oxygen absorbing substance-containing layer 11a contains at least an oxygen absorbing substance and a binder resin. The oxygen absorbing substance contained in the oxygen absorbing substance-containing layer 11a may be, for example, a phenol compound, a reducing saccharide such as glucose, or a polyhydric alcohol such as glycerin, and a phenol compound is preferable in one form. Examples of the phenol compound include gallic acid, ascorbic acid, catechol, hydroxybenzoic acid and the like. 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. The phenolic compound having a pyrogallol group may be, for example, gallate (3,4,5-trihydroxybenzoic acid) and gallate ester (eg, propyl gallate, ethyl gallate, octyl gallate, etc.). In one form, the oxygen-absorbing substance-containing layer 11a may contain at least one selected from gallic acid and gallic acid esters (hereinafter, also referred to as “gallic acids”) as the oxygen-absorbing substance, and may contain gallic acid and gallic acid. It may contain at least one of propyl gallate. Since these are food additives and are relatively inexpensive, it is possible to provide a packaging material that is safe and inexpensive and has excellent oxygen absorption performance.

The alkaline substance-containing layer 11b contains at least an alkaline substance and a binder resin. As alkaline substances, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, rubidium hydroxide, beryllium hydroxide, magnesium hydroxide, strontium hydroxide, barium hydroxide, lithium carbonate, magnesium carbonate, potassium carbonate, Examples thereof include lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium potassium carbonate, sodium carbonate, potassium magnesium carbonate, potassium phosphate, potassium hydrogen phosphate, sodium citrate and the like. From the viewpoint of safety, it is preferably a food additive, and more preferably one having heat resistance enough to be kneaded into a thermoplastic resin.

The binder resin used for the oxygen absorbing substance-containing layer 11a and the alkaline substance-containing layer 11b of the oxygen absorbing layer 11 has an affinity with an aqueous solution containing an oxide of galvanic acid, an alkaline substance and water produced during oxygen absorption. Is required. By having an affinity, the compatibility with the aqueous solution is improved, and it becomes possible to obtain a state in which the aqueous solution is uniformly diffused in the oxygen absorption layer. Therefore, it is preferable to use a resin containing a large number of hydrophilic groups as a main component in the skeleton, and as an example of a resin containing a large number of hydrophilic groups, a cellulosic resin such as polyvinyl alcohol, polyvinyl acetal, polyvinylpyrrolidone, and carboxylmethylcellulose, or resole. Examples thereof include water-soluble resins such as type phenol resin, methylolated urea (urea) resin, methylolated melamine resin, polyethylene oxide and polyacrylamide, and modified resins thereof. Further, copolymers such as acrylic / methacrylic resin, urethane resin and polyester resin incorporating a monomer having a hydrophilic group and modified silicone resin can also be mentioned.

In the present invention, the resin used for the oxygen absorbing substance-containing layer 11a and the alkaline substance-containing layer 11b of the oxygen absorbing layer 11 is preferably water-insoluble. Since the resin component is not dissolved by the aqueous solution consisting of the substance and water, it is possible to suppress exudation and the like. From this point of view, a resin modified with a water-soluble resin is preferable, and a resin modified with polyvinyl alcohol is particularly preferable. Polyvinyl alcohol is suitable because it does not contain an ester bond in the skeleton and is less likely to cause deterioration of the resin due to water such as hydrolysis or alkaline water. On the other hand, the content ratio of the hydrophilic group in the resin modified to obtain the affinity with the aqueous solution is preferably 20 to 40 mol%. From this point of view, polyvinyl acetal resin is preferable. Polyvinyl acetal has a structure in which a part of the hydroxyl group, which is a hydrophilic group of polyvinyl alcohol, is modified to a hydrophobic group by acetaldehyde or the like, and polyvinyl acetal, polyvinyl butyral, and those in which these structures are mixed in the skeleton are generally used. Will be done.

An additive for improving the strength of the layer, adhesion to other layers, and obtaining weather resistance may be used for the oxygen absorbing layer 11, and a cross-linking agent such as isocyanate, a plasticizer, an ultraviolet absorber, and an antioxidant may be used. Additives such as agents may be used.

The content of the oxygen absorbing substance is preferably 10 to 50% by mass with respect to the total weight of the oxygen absorbing substance-containing layer 11a, and the content may be adjusted according to the oxygen absorbing property and the strength as a film. .. When the content of the oxygen absorbing substance is less than 10% by mass, it is necessary to thicken the oxygen absorbing substance layer in order to obtain oxygen absorbing property, which is difficult with a general-purpose film forming means. On the other hand, when the content of the oxygen absorbing substance exceeds 50% by mass, the amount of the resin composition containing the binder resin as the main component is reduced, and exudation is likely to occur, or the strength of the oxygen absorbing substance-containing layer or other layers. It may be difficult to adjust the adhesion of the resin.

The thickness of the oxygen absorbing substance-containing layer 11a may be adjusted according to the oxygen absorption property, and is not particularly limited, but is preferably 2 to 50 μm, which can be formed by a general-purpose film forming means.

The alkaline substance is preferably contained in the alkaline substance-containing layer 11b at a ratio of 20% by mass to 100% by mass with respect to 100 parts by mass of the oxygen absorbing substance. If the content of the alkaline substance is less than 20% by mass of the oxygen absorbing substance, sufficient oxygen absorption cannot be obtained, and even if it exceeds 100% by mass, a significant increase in oxygen absorption cannot be expected.

The thickness of the alkaline substance-containing layer 11b is not limited as long as it can absorb oxygen, but is preferably 0.1 to 50 μm, which can be formed by a general-purpose film forming means.

The type of coater and printing machine used for coating the oxygen absorbing substance-containing layer 11a and the alkaline substance-containing layer 11b, and the coating method thereof are not particularly limited. Typical examples are gravure coaters such as direct gravure method, reverse gravure method, kiss reverse gravure method, offset gravure method, reverse roll coater, micro gravure coater, chamber doctor combined coater, air knife coater, dip coater, bar coater, etc. Examples include a comma coater and a die coater.

(Innermost layer)
The laminated body 1 according to the embodiment shown in FIG. 1 includes an innermost layer 12. The innermost layer 12 is a layer constituting the surface of the laminated body 1 opposite to the outermost layer 10 as a base material.

When the use of the laminated body 1 is a packaging material and it is used as a bag-shaped body or the like, it is preferable that the innermost layer 12 includes a sealant layer. The sealant layer imparts heat-sealing property to the laminated body 1. In this case, for example, the laminated body 1 can be easily processed into a bag shape by laminating the laminated body 1 with the sealant layer, which is the innermost layer 12, inside, and heat-sealing the peripheral edge portion and the like.

Of the thermoplastic resins, polyolefin resins are generally used as the sealant layer, and specifically, low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), and linear low-density polyethylene resin (LLDPE). ), Ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, ethylene-methacrylic acid resin copolymer and other ethylene-based resins, polyethylene-polybutene blend resin, homopolypoly resin (PP). , A polypropylene-based resin such as a propylene-ethylene random copolymer, a propylene-ethylene block copolymer, and a propylene-α-olefin copolymer can be used.

<Packaging>
The package according to the present embodiment includes the above-mentioned laminated body. Specifically, at least a part of the package is formed of the above-mentioned laminate. The package according to the present embodiment may be further provided with functional layers such as a printing layer, a barrier layer, and a surface protective layer.

Examples of applications of the package of the present embodiment include, for example, a bag, an MA packaging material, a lid material (top material), a sheet, a bag with a zipper, and a cover film. Further, the bag-shaped package may be formed by heating and laminating the peripheral portions of the two above-mentioned laminated bodies in a state where the innermost sealant layer is arranged on the inner side. Further, a third film may be interposed in the peripheral portion to be bonded to form a bag with a so-called "gusset".

The bag-shaped package may have any shape including a rectangle, a circle, and a triangle. Further, as the bag with a zipper, a bag having a fitting portion that can be opened and closed may be provided at the opening of the package of the bag-shaped body by machining.

<Packaging goods>
The packaged article according to the present embodiment includes the above-mentioned package and the contents contained therein. Examples of the contents contained in the above-mentioned package include, but are not limited to, foods, beverages, cosmetics, pharmaceuticals, industrial materials, medical instruments, electronic devices, and cultural properties. In the packaged article according to the present embodiment, when the content contained in the package is a food product, the food product may be a food product having high water activity. Foods with high water activity include, for example, wheat flour with a water activity of 0.8 to 0.87, rice, beans, fruit cakes, dried shirasu with a water activity of 0.87 to 0.91, salted salmon, sponge cake, etc. Examples thereof include cheeses of 0.91 to 0.95, fruit juices, meats with a water activity of 0.95 to 1.0, hams, bacon, sausages, fresh fish, eggs, fruits and the like.

<Example 1>
The outermost layer is a film in which a polyester film having a thickness of 12 μm is bonded to the barrier layer side of the barrier film GL-AE (made by Toppan Printing, thickness 12 μm) having a barrier layer having oxygen barrier properties and water vapor barrier properties via an adhesive layer. It was used as a base material. In order to obtain adhesion to an oxygen absorbing substance-containing layer, which will be described later, an anchor layer containing a urethane resin as a main component was formed on the surface of a polyester film having a thickness of 3 μm. To form the oxygen absorbing substance-containing layer, polyvinyl butyral resin (hydroxyl content 21 mol%) is used as the binder resin, gallic acid is used as the oxygen absorbing substance, and ethyl acetate is used as the solvent. The layer was coated with a wire bar and dried. The thickness (after drying) of the oxygen absorbing substance-containing layer was 10 μm. The content of gallic acid was 30% by mass of the total mass (solid content) of the oxygen absorber-containing layer.

Next, a coating composition was prepared by mixing polyvinyl butyral resin, sodium carbonate, which is an alkaline substance, and ethyl acetate, and the coating composition was applied onto the oxygen absorbing substance-containing layer with a wire bar. Formed a layer. Sodium carbonate was 60% by mass with respect to 100 parts by mass of the oxygen absorbing substance, and 30% by mass with respect to the total mass of the alkaline substance-containing layer.

A urethane-based adhesive was applied on the alkaline substance-containing layer with a wire bar so as to have a thickness of 3 μm after drying, and an LLDPE film (thickness: 30 μm) was bonded to this as a sealant layer to prepare a laminate. ..

<Example 2>
A laminate was produced in the same manner as in Example 1 except that polyvinyl acetal (hydroxyl content: 25 mol%) was used as the binder used for the oxygen absorbing substance-containing layer and the alkaline substance-containing layer.

<Example 3>
Same as Example 1 except that the binder used for the oxygen absorbing substance-containing layer and the alkaline substance-containing layer is a polyvinyl acetal resin (hydroxyl content 32 mol%) in which the skeletons of polyvinyl butyral and polyvinyl acetal are mixed in the molecule. A laminate was prepared in.

<Comparative Example 1>
As a binder used for the oxygen-absorbing substance-containing layer, polyvinyl alcohol (hydroxyl content: 88 mol%), which is a water-soluble resin, was used to prepare a coating liquid using water as a solvent, and the oxygen-absorbing substance-containing layer was prepared in the same manner as in Example 1. Was produced. As the alkaline substance-containing layer, a coating composition using polyvinyl acetal as a binder was prepared in the same manner as in Example 2, and laminated on the oxygen-absorbing substance-containing layer using the above-mentioned polyvinyl alcohol. After laminating the alkaline substance-containing layer, an LLDPE film was laminated using a urethane-based adhesive in the same manner as in Examples 1 and 2, to prepare a laminated body.

<Evaluation method>
(Oxygen absorption performance)
With respect to the laminate prepared above, a bag was prepared by laminating the laminate by heat sealing. The size of the bag was 10 cm wide x 10 cm long, excluding the seal part. A cloth containing 1.5 g of tap water was contained in the bag, and 100 cc of air was injected to seal the bag. After storing the prepared sample in a constant temperature bath at 40 ° C. for a certain period of time, the oxygen concentration in the bag was measured, and the oxygen absorption amount of each was confirmed from the difference from the initial oxygen concentration. When the residual oxygen amount was 10% or less, it was evaluated as "+", and when it was 10%, it was evaluated as "-".

(Exudation)
The state of the bag after evaluating the above oxygen absorption performance was evaluated. It was confirmed by visual observation and wiping with a cotton swab etc. whether the liquid had exuded from the end of the bag.

As shown in Table 1, in the case of Comparative Example 1, the exudation of the liquid was confirmed, and in Examples 1 to 3, it can be seen that the exudation was suppressed while maintaining sufficient oxygen absorption performance.

From the above results, it was confirmed that the laminate according to the embodiment of the present invention suppressed the exudation of the liquid while maintaining the oxygen absorption performance, and the practicality as a package was improved.

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, in which case the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent elements are deleted can be extracted as an invention.

The present invention can be used as a packaging material for foods, drugs, pharmaceuticals, cosmetics, electronic parts and the like.

1 Laminated body 10 Outermost layer 11 Oxygen absorbing layer 11a Oxygen absorbing substance-containing layer 11b Alkaline substance-containing layer 12 Innermost layer

Claims (11)

In a laminated body including an outermost layer, an oxygen absorbing layer, and an innermost layer in this order, the oxygen absorbing layer comprises at least an oxygen absorbing substance-containing layer containing an oxygen absorbing substance and a binder resin, and at least an alkaline substance and a binder resin. A laminate comprising an alkaline substance-containing layer containing the oxygen-absorbing substance, and the main component of the binder resin contained in the oxygen-absorbing substance-containing layer and the alkaline substance-containing layer is a water-insoluble resin having a hydroxyl group in a side chain. body. The laminate according to claim 1, wherein the binder resin is a resin obtained by modifying polyvinyl alcohol, and the content ratio of the hydroxyl groups of the modified resin is 20 to 40 mol%. The laminate according to claim 1 or 2, wherein the binder resin is a polyvinyl acetal resin. The laminate according to any one of claims 1 to 3, wherein the oxygen absorbing substance is contained in a ratio of 10% by mass to 50% by mass with respect to the total mass of the oxygen absorbing substance-containing layer. The laminate according to any one of claims 1 to 4, wherein the alkaline substance is contained in a ratio of 20 parts by mass to 100 parts by mass with respect to 100 parts by mass of the oxygen absorbing substance. The laminate according to any one of claims 1 to 5, which contains at least a phenol compound as the oxygen absorbing substance. The laminate according to any one of claims 1 to 6, which contains at least a phenol compound having a pyrogallol group as the oxygen absorbing substance. The laminate according to any one of claims 1 to 7, which contains at least one selected from gallic acid and gallic acid ester as the oxygen absorbing substance. The laminate according to any one of claims 1 to 8, wherein the innermost layer includes a sealant layer. A package including the laminate according to any one of claims 1 to 9. A packaged article including the package according to claim 10 and the contents contained therein.

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