JP2020082437A - Laminate, package and packaged article - Google Patents

Abstract

To provide a laminate capable of exerting a more excellent oxygen absorption performance while maintaining a laminate strength sufficient for putting into practical use as a packaging medium, and also to provide a package and a packaged article including the laminate.SOLUTION: A laminate include: a first outermost layer, an intermediate layer including an oxygen absorption layer containing an oxygen absorber; and a second outermost layer in this order. The first outermost layer includes: a substrate in which one principal surface composes an outermost surface of the laminate; and a metal-containing layer neighboring the intermediate layer. The intermediate layer includes a silane coupling agent in a layer neighboring the metal containing layer.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminate, a package and a packaged article.

In order to prevent the oxidative deterioration of the packaged contents, it is effective to remove the oxygen inside the package and to block the oxygen outside the package from entering the inside. However, since the packaging work is generally performed in the atmosphere, the packaging is performed with oxygen contained therein.

As a means for packaging so that oxygen does not remain in the packaging, a degassing packaging, a vacuum packaging, a gas displacement packaging, or the like may be used. However, when such a special packaging means is used, it is necessary to prepare a special filling and packaging facility, resulting in a high facility cost, or a disadvantage that the filling and packaging speed does not increase and the production efficiency decreases. .. Further, even if the packaging is performed by the above means so that oxygen does not remain during the packaging, if the outside oxygen invades through the packaging material after the packaging, the oxygen is not blocked.

Therefore, there is a case where a means for removing oxygen remaining in the package and oxygen invading after the packaging by enclosing a drug having an oxygen absorbing property in the package may be used. In this method, it is possible to remove and block oxygen for a certain period of time, that is, within a period in which the ability of the oxygen absorbing agent is maintained, which is a very effective means. However, when this means is used, it is necessary to fill a sachet containing an oxygen absorbing agent, that is, a so-called oxygen absorber, separately from the contents, which is a trouble.

As a means for eliminating and blocking oxygen in the packaging for a certain period of time by eliminating this drawback, a means for imparting oxygen absorbing performance to the film itself constituting the packaging material has been devised and partially put into practical use.

At present, packaging materials having oxygen absorption performance are often used in the food packaging field. In particular, it is often used for packaging long-term storage foods such as retort foods (high-temperature high-pressure sterilized foods) and foods with a high water content that easily cause mold.

For long-term preserved foods such as retort foods, when the packaging form is canned or bottled, there is almost no permeation of oxygen from the outside, so it suffices to pay attention only to the residual oxygen during filling and packaging, and vacuum packaging and nitrogen gas replacement. Packaging is used. However, in recent years, due to problems such as transportation costs and disposal of containers, the use of cans and bottles has decreased, while on the other hand, the form of retort pouch packaging material with an oxygen absorbing film as part of the packaging material has become mainstream. There is.

The packaging material having oxygen absorbability includes an oxygen barrier base material layer, an oxygen absorbent layer, and a sealant layer as main constituent elements, and also has functions of oxygen barrier property, oxygen absorbability, and heat seal property. As the oxygen barrier base material layer, an aluminum base material having an aluminum foil or an aluminum vapor deposition layer, an inorganic oxide vapor deposition film that is a transparent oxygen barrier base material, or the like is used.

In the oxygen absorbing layer, an oxygen absorbing substance as a main agent, an alkaline substance as an auxiliary agent, an oxidation reaction catalyst and the like are added to a base resin and a binder. Iron-based oxygen-absorbing substances are usually added to oxygen-absorbing packaging materials that are currently in practical use. The iron-based oxygen absorbing substance is used because it is excellent in its high oxygen absorbing ability and safety.

However, after filling and packaging foods, the use of metal detectors is increasing in order to inspect for the presence of foreign substances such as metals.In that case, use an oxygen-absorbing packaging material containing an iron-based oxygen-absorbing substance. You cannot do it. In order to deal with this problem, development of an oxygen absorbing packaging material using an organic oxygen absorbing substance is under way.

Examples of organic oxygen absorbing substances include ascorbic acids, reducing sugars such as glucose, polyhydric alcohols such as glycerin, phenols such as catechol, and phenolcarboxylic acids such as hydroxybenzoic acid. These organic substances have been studied for a long time as oxygen absorbing substances for oxygen absorbers, and are inexpensive and safe.

For example, as an oxygen-absorbing packaging material using gallic acid (3,4,5-trihydroxybenzoic acid) among phenolcarboxylic acids as an oxygen-absorbing substance, Patent Document 1 discloses gallic acid and an alkaline substance in a thermoplastic resin. , An oxygen absorbing film formed from a resin composition obtained by adding an oxidation reaction catalyst. Further, Patent Document 2 discloses an oxygen absorption film in which a base material, a gallic acid-containing layer, an alkaline substance-containing layer, and a sealant layer are laminated in this order.

JP, 2011-92921, A JP, 10-138410, A

The present inventors formed an oxygen-absorbing layer containing an organic oxygen-absorbing substance such as gallic acid on an oxygen-barrier substrate film, and then laminating a sealant layer on the oxygen-absorbing film to produce an oxygen-absorbing film. Repeated research. As a result, it has been found that the oxygen absorbing film having such a structure is excellent in oxygen absorbing performance, but the laminating strength is not always sufficient and particularly delamination is likely to occur between the base material and the oxygen absorbing layer. ..

In the formation of the oxygen absorbing layer containing an oxygen absorbing substance, a general polyester-based two-component curing type coating liquid was used as a binder coating liquid serving as a base for forming a film. This coating liquid was a binder coating liquid capable of forming an oxygen absorbing layer having a sufficient laminating strength with a base material when it did not contain an oxygen absorbing substance such as gallic acid.

Therefore, it is clear that the laminating strength was lowered by adding the oxygen absorbing substance such as gallic acid to the coating liquid. Also, it has been confirmed that the laminate strength is improved by reducing the amount of addition of an oxygen absorbing substance such as gallic acid, but this results in a decrease in oxygen absorbing performance. Therefore, a technique capable of improving the oxygen absorption performance while maintaining the laminate strength is required.

Therefore, the present invention, while maintaining a sufficient laminate strength to be practically used as a packaging material, a laminate capable of exhibiting more excellent oxygen absorption performance, and a package and a packaged article containing the same To do.

According to the first aspect of the present invention, a laminate including a first outermost layer composed of two or more layers, an intermediate layer composed of two or more layers, and a second outermost layer composed of a single layer or two or more layers in this order. The first outermost layer includes a base material whose one main surface constitutes the outermost surface of the laminate, and a metal-containing layer adjacent to the intermediate layer, and the intermediate layer has oxygen absorption. Provided is a laminate including an oxygen-absorbing layer containing a substance and including a silane coupling agent in a layer adjacent to the metal-containing layer.

In one form, the layer containing the silane coupling agent adjacent to the metal-containing layer may be the oxygen absorption layer.

In another aspect, the metal-containing layer may be a vapor deposition layer or an aluminum foil.

In another aspect, the first outermost layer may include the substrate, a vapor deposition layer or an aluminum foil, and an overcoat layer in this order, and the metal-containing layer may be the overcoat layer.

In another form, the overcoat layer may further contain a silane coupling agent.

In another aspect, the intermediate layer includes an anchor coat layer between the metal-containing layer and the oxygen absorbing layer, and the layer containing a silane coupling agent adjacent to the metal-containing layer is the anchor coat layer. You may.

In another aspect, the metal-containing layer may be a metal-containing overcoat layer, a metal-containing vapor deposition layer, or an aluminum foil.

In another aspect, the oxygen absorbing layer may further contain a silane coupling agent.
In another embodiment, the laminate may contain the oxygen absorbing substance in an amount of 20% by mass or more based on the total mass of the oxygen absorbing layer.

In another embodiment, at least one of the layers containing a silane coupling agent contains a polyurethane resin which is a reaction product of a polyol compound and an isocyanate compound, and has an isocyanate functional group as the silane coupling agent. May be included.

In another aspect, the laminate may contain, as the oxygen absorbing substance, at least one selected from gallic acid and gallic acid esters.

In another aspect, the laminate may further include an alkaline substance-containing layer between the oxygen absorption layer and the second outermost layer.

In another form, the oxygen absorption layer may further contain an alkaline substance.
In another aspect, the laminate may contain at least sodium carbonate as the alkaline substance.
In another form, the second outermost layer may include a sealant layer.

According to the 2nd side surface of this invention, the package body containing the said laminated body is required.
According to a third aspect of the present invention, there is provided a packaged article including the package and the contents contained in the package.

ADVANTAGE OF THE INVENTION According to this invention, the laminated body which can be used as a packaging material which can exhibit more excellent oxygen absorption performance, while maintaining sufficient laminating strength for practical use as a packaging material, the packaging body containing it, and a packaging article are provided. ..

Sectional drawing which shows schematically the laminated body which concerns on one Embodiment of this invention. Sectional drawing which shows schematically the laminated body which concerns on other embodiment of this invention.

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

<Laminate>
The laminated body according to the present embodiment will be described below with reference to the drawings. It should be noted that elements having similar or similar functions are designated by the same reference numerals, and overlapping description will be omitted.

The laminate according to the present embodiment is a layer included in the first outermost layer, the layer adjacent to the intermediate layer is a metal-containing layer, and the intermediate layer adjacent to the metal-containing layer contains a silane coupling agent. contains. A typical configuration example is shown in FIGS.

FIG. 1 is a cross-sectional view schematically showing the laminated body 1 according to the first embodiment, in which the oxygen absorption layer 22 adjacent to the overcoat layer 10c which is a metal-containing layer contains a silane coupling agent. Show. That is, the laminated body 1 includes the first outermost layer 10, the intermediate layer 20, and the second outermost layer 30. The first outermost layer 10 includes a base material 10a, a vapor deposition layer or an aluminum foil 10b, and an overcoat layer 10c. The overcoat layer 10c is a metal-containing layer containing a metal. The intermediate layer 20 includes an oxygen absorption layer 22 and an alkaline substance containing layer 23. In the intermediate layer 20, the oxygen absorption layer 22 adjacent to the overcoat layer 10c, which is a metal-containing layer, contains a silane coupling agent.

As a preferable modified example, the laminate 1 according to the first embodiment may further include a silane coupling agent in the overcoat layer 10c in addition to the oxygen absorption layer 22 that is a silane coupling agent-containing layer.

FIG. 2 is a cross-sectional view schematically showing the laminated body 1 according to the second embodiment, in which the anchor coat layer 21 adjacent to the vapor deposition layer which is the metal-containing layer or the aluminum foil 10b contains the silane coupling agent. The following shows the form. That is, the laminated body 1 includes the first outermost layer 10, the intermediate layer 20, and the second outermost layer 30. The first outermost layer 10 includes a base material 10a and a vapor deposition layer or an aluminum foil 10b. The vapor deposition layer or the aluminum foil 10b is a metal-containing layer containing a metal. The intermediate layer 20 includes an anchor coat layer 21, an oxygen absorption layer 22, and an alkali substance containing layer 23. In the intermediate layer 20, the anchor coat layer 21 adjacent to the vapor deposition layer which is the metal-containing layer or the aluminum foil 10b contains a silane coupling agent.

As a preferable modification, the laminate 1 according to the second embodiment may further include a silane coupling agent in the oxygen absorption layer 22 in addition to the anchor coat layer 21 that is a silane coupling agent-containing layer.

Moreover, the laminated body 1 which concerns on 2nd embodiment is a metal containing layer with which the 1st outermost layer 10 is provided as another modification, and the layer adjacent to the intermediate|middle layer 20 is an overcoat containing a metal. It may be a layer.

In addition, in the laminated body 1 shown in FIGS. 1 and 2, an adhesive layer (not shown) may be provided between any layers.

The materials and functions of each layer will be described below. In the following, the “metal-containing layer” means a metal-containing layer included in the first outermost layer 10 and a layer adjacent to the intermediate layer 20. For example, in the laminate 1 shown in FIG. 1, the “metal-containing layer” means the overcoat layer 10c, not the vapor deposition layer or the aluminum foil 10b. In the laminated body 1 shown in FIG. 2, the “metal-containing layer” means a vapor deposition layer or an aluminum foil 10b.

(First outermost layer)
The first outermost layer is a base material having two or more oxygen barrier properties, and at least a base material having one main surface forming the outermost surface of the laminate and a metal-containing layer adjacent to the intermediate layer. Including. The metal-containing layer may be, for example, a vapor deposition layer containing a metal, an aluminum foil, or an overcoat layer containing a metal.

In the first embodiment shown in FIG. 1, the first outermost layer 10 includes a base material 10 a whose one main surface constitutes the outermost surface of the laminate, and a metal as a metal-containing layer adjacent to the intermediate layer 20. It includes an overcoat layer 10c contained therein, and a vapor deposition layer or an aluminum foil 10b interposed between the base material 10a and the overcoat layer 10c.

In the second embodiment shown in FIG. 2, the first outermost layer 10 includes a base material 10 a whose one main surface constitutes the outermost surface of the laminate, and a metal as a metal-containing layer adjacent to the intermediate layer 20. The vapor deposition layer or the aluminum foil 10b containing it is provided.

Examples of the base material 10a include polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon (registered trademark)), polyethylene naphthalate, etc., or a copolymer of these polymers. What is usually used as a packaging material such as coalescence can be used. Further, among the resin films, a resin film such as polyvinyl alcohol, ethylene vinyl alcohol, or polyvinylidene chloride, which has a relatively high barrier property, or a coating material of these coating liquids on a plastic substrate can be used. The base material 10a is appropriately selected from the above materials according to the application, the layer structure of the first outermost layer, and the like.

The base material 10a 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 vapor-deposited layer or the vapor-deposited layer in the aluminum foil 10b may be an aluminum vapor-deposited film, for example, an oxide, a nitride, or a fluoride of aluminum, titanium, zirconium, tin, or magnesium, or a simple substance thereof. It may be a composite. As described in the background section, it is desirable to use an inorganic oxide vapor deposition layer such as a silicon oxide vapor deposition layer or an aluminum oxide vapor deposition layer in order to enable the metal detector to be used for foreign matter inspection.

These vapor deposition layers are formed by a vacuum process such as a vacuum vapor deposition method, a sputtering method, and a plasma chemical vapor deposition (CVD method). When the first outermost layer 10 includes the vapor deposition layer or the aluminum foil 10b, the oxygen barrier property can be further enhanced.

The overcoat layer 10c can exert an effect of preventing the generation of cracks or repairing the generated cracks by covering the vapor deposition layer 10b, for example. Therefore, when the first outermost layer 10 includes the overcoat layer 10c, the oxygen barrier property can be further enhanced.

The overcoat layer 10c contains at least a metal component and a binder. The metal component contained in the overcoat layer 10c is preferably a metal alkoxide or a hydrolyzate thereof, and the binder contained in the overcoat layer 10c is preferably a water-soluble polymer having a hydroxyl group in one form. .. Examples of the water-soluble polymer include urethane resin, phenol resin, acrylic resin, polyester/alkyd resin, amino resin and the like.

As the metal alkoxide, for example, tetraethoxysilane [Si _{(OC 2} H _{5) 4],} triisopropoxyaluminum _{[Al (O-i-C 3} H 7) 3 ] such as the general formula:
M(OR) _n
(M: Si, Ti, Ai, Zr, and other metals, R: CH ₃ , C ₂ H _{5, and} other alkyl groups). Of these, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

The overcoat layer 10c is, for example, a solution obtained by dissolving a water-soluble polymer in an aqueous solvent (water or a water/alcohol mixed solution), and mixing a solution obtained by directly treating the metal alkoxide or by previously hydrolyzing the metal alkoxide. Can be formed by coating the vapor-deposited layer 10b on the substrate 10a and heating and drying it.

The overcoat layer 10c may contain a silane coupling agent. In particular, when the oxygen absorbing layer 22 adjacent to the overcoat layer 10c that is a metal-containing layer contains a silane coupling agent as in the first embodiment shown in FIG. 1, the overcoat layer 10c also contains silane. It is preferable to contain a coupling agent from the viewpoint of adhesion.

When the overcoat layer 10c contains a silane coupling agent, the content rate of the silane coupling agent may be 0.1% by mass to 5% by mass based on the total mass of the overcoat layer 10c, and is 0.5% by mass. It may be from mass% to 2.0 mass %.

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

Below, the 1st outermost layer 10 may be called a "base material layer" or a "base material film." Examples of the first outermost layer composed of the base material film including the base material 10a, the vapor deposition layer or the aluminum foil 10b, and the overcoat layer 10c include commercially available products such as trade name "GL-AE" (manufactured by Toppan Printing Co., Ltd.). Goods can be used.

(Middle layer)
The intermediate layer is composed of two or more layers. In the first embodiment shown in FIG. 1, the intermediate layer 20 includes an oxygen absorption layer 22 and an alkaline substance-containing layer 23. In the second embodiment shown in FIG. 2, the intermediate layer 20 includes an anchor coat layer 21, an oxygen absorption layer 22, and an alkali substance containing layer 23.

(Oxygen absorption layer)
The oxygen absorbing layer 22 contains at least an oxygen absorbing substance and a binder, and further contains a silane coupling agent if necessary. That is, like the first embodiment shown in FIG. 1, when the intermediate layer adjacent to the metal-containing layer (overcoat layer 10c) is the oxygen absorbing layer 22, the oxygen absorbing layer 22 further contains a silane coupling agent. contains. When the intermediate layer adjacent to the metal-containing layer (deposition layer or aluminum foil 10b) is the anchor coat layer 21 and the layer contains a silane coupling agent as in the second embodiment shown in FIG. In addition, the oxygen absorption layer 22 may further contain a silane coupling agent as a preferable form.

The higher the content of the oxygen-absorbing substance in the oxygen-absorbing layer 22, the higher the oxygen-absorbing performance. It was difficult to raise. In the laminate according to the present embodiment, the intermediate layer adjacent to the metal-containing layer contains a silane coupling agent, whereby the adhesion between the base material and the intermediate layer can be improved, and thus the oxygen-absorbing substance It has become possible to increase the content rate. For example, since high laminate strength can be maintained even when 30 mass% or more of an oxygen absorbing substance is added based on the total mass of the oxygen absorbing layer 22, the laminate strength and the oxygen absorbing performance can be satisfied at a high level in a well-balanced manner. An oxygen absorbing film can be provided.

The preferable content of the oxygen-absorbing substance in the oxygen-absorbing layer 22 is appropriately set from the viewpoint of the balance between the oxygen-absorbing performance and the laminate strength, and the film forming property. For example, the content rate of the oxygen-absorbing substance may be 20% by mass or more, 25% by mass or more, and 30% by mass or more based on the total mass of the oxygen absorbing layer 22. Further, it may be 65% by mass or less, 60% by mass or less, and 55% by mass or less based on the total mass of the oxygen absorption layer 22.

The oxygen-absorbing substance contained in the oxygen-absorbing layer 22 is preferably an organic material in consideration of foreign matter inspection with a metal detector, and ascorbic acids, reducing sugars such as glucose, polyhydric alcohols such as glycerin, and catechol. Specific examples include phenols and phenolcarboxylic acids such as hydroxybenzoic acid. Phenols and hydroxybenzoic acid are preferable in consideration of heat resistance when the coating liquid is dried and adverse effects such as oxygen absorption components in the coating film absorbing atmospheric moisture and deliquescing in the manufacturing process. Considering the oxygen absorption performance per mole, trihydroxybenzoic acid (gallic acid) having three hydroxy groups, gallic acid ester (eg, propyl gallate, ethyl gallate, octyl gallate, etc.) and the like are preferable.

The binder contained in the oxygen absorbing layer 22 is not particularly limited, and polyester resin, polyurethane resin, polyether resin, acrylic resin, epoxy resin, ethylene-vinyl acetate resin, vinyl chloride. Examples of the resin include a resin, a silicone resin, and a rubber resin. When the oxygen absorbing layer 22 contains a silane coupling agent, when an isocyanate type silane coupling agent is used, it is preferable to use a polyurethane resin as a binder in combination with the isocyanate type silane coupling agent.

When the oxygen absorbing layer 22 contains a silane coupling agent, the content of the silane coupling agent may be 0.1% by mass to 5.0% by mass based on the total mass of the oxygen absorbing layer 22, and It may be from 0.5% to 2.0% by weight.

The oxygen absorption layer 22 may further contain an alkaline substance. The laminated body 1 according to the first embodiment and the second embodiment shown in FIGS. 1 and 2 has an alkaline substance-containing layer 23, which will be described later, between the oxygen absorbing layer 22 and the second outermost layer 30. However, as another embodiment, the alkaline substance-containing layer 23 may not be provided, and the oxygen absorbing layer 22 may contain the alkaline substance in a form in which the oxygen absorbing substance and the alkaline substance are mixed. ..

In the laminate 1, the alkaline substance functions as an auxiliary agent that promotes oxygen absorption by the oxygen absorbing substance. For example, gallic acids are known to exhibit an excellent oxygen absorption function by reacting with oxygen in an environment in which an alkaline substance and water are present. The reaction of gallic acids proceeds sufficiently at pH 8 or higher.

When the oxygen absorbing layer 22 contains an alkaline substance, the alkaline substance may be 40 parts by mass to 100 parts by mass, and 50 parts by mass to 100 parts by mass of the oxygen absorbing substance contained in the oxygen absorbing layer 22. It may be 100 parts by weight.

Further, the oxygen absorption layer 22 may contain any additive such as a plasticizer, an antioxidant, a colorant, a filler, and an ultraviolet absorber, if necessary.

Considering the heat resistance of the oxygen absorbing substance to be blended, it is preferable that the oxygen absorbing layer 22 is formed as a coating film by coating with the coating liquid rather than kneading into a resin and extruding to form a film. The coating method is not particularly limited and may be a known method such as a dipping method, a screen printing method, a spray method, a die coating method, or a roll coating method. From a viewpoint of this point of view, the roll coating method is preferable since it is practically a roll-up coating on a film. Among the roll coating methods, the gravure coating method is also suitable, which allows relatively thick film coating. The film thickness of the oxygen absorption layer 22 is preferably as thick as possible from the viewpoint of oxygen absorption performance, but is limited by cost and coating method, and the film thickness after drying is about 1 μm to 10 μm in a realistic film thickness range. is there.

(Anchor coat layer)
The laminate 1 according to the second embodiment shown in FIG. 2 has an anchor coat layer 21 between these layers in order to improve the adhesion between the metal-containing layer (deposition layer or aluminum foil 10b) and the oxygen absorbing layer 22. Equipped with. When the intermediate layer adjacent to the metal-containing layer (deposition layer or aluminum foil 10b) is the anchor coat layer 21 as in the layered product 1, the anchor coat layer 21 contains at least a silane coupling agent and a binder. By mixing the silane coupling agent, the adhesion between the anchor coat layer 21 and the oxygen absorbing layer 22 is improved, and the content of the oxygen absorbing substance in the oxygen absorbing layer can be increased. It is possible to obtain an oxygen-absorbing film that satisfies the performance at a high level in a well-balanced manner. As a more preferable form, as described above, the oxygen absorption layer 22 adjacent to the anchor coat layer 21 may also contain a silane coupling agent.

The binder contained in the anchor coat layer 21 is not particularly limited, but it is preferable to use a resin of the same type as the oxygen absorption layer 22 from the viewpoint of adhesion with the oxygen absorption layer 22. When using an isocyanate-based silane coupling agent, it is preferable to use a polyurethane-based resin as a binder in combination with the isocyanate-based silane coupling agent.

The content of the silane coupling agent in the anchor coat layer 21 may be 0.1% by mass to 5.0% by mass, based on the total mass of the anchor coat layer 21, and 0.5% by mass to 2.0% by mass. May be %.

(Alkaline substance-containing layer)
The laminated body 1 according to the first embodiment shown in FIG. 1 and the laminated body 1 according to the second embodiment shown in FIG. 2 are both alkaline between the oxygen absorbing layer 22 and the second outermost layer 30. The substance-containing layer 23 is provided. As described above, when the oxygen absorption layer 22 contains an alkaline substance, the laminate 1 does not have to include the alkaline substance-containing layer 23.

However, when an oxygen absorbing substance and an alkaline substance are mixed in the oxygen absorbing layer 22, the oxygen absorbing performance is exhibited, but the oxygen absorbing substance starts to absorb oxygen at the preparation stage of the coating liquid. Therefore, as compared with the laminated body 1 according to the first embodiment and the second embodiment, the laminated body is manufactured as compared with the case where the oxygen absorption layer 22 and the alkaline substance-containing layer 23 exist as separate layers. There is a problem that the oxygen absorption performance is deteriorated later. Therefore, as shown in FIGS. 1 and 2, the laminate preferably includes the oxygen absorption layer 22 and the alkaline substance-containing layer 23 as separate layers.

The alkaline substance-containing layer 23 contains at least an alkaline substance and a binder. The alkaline substance contained in the alkaline substance-containing layer 23 moves to the oxygen absorbing layer 22 which is in direct contact therewith, and the pH of the oxygen absorbing layer 22 is adjusted by the action of the alkaline substance containing layer 23 so that hydrogen is released from the hydroxy group of the oxygen absorbing substance. It is easy to pull out and oxygen absorption is promoted.

The alkaline substance contained in the alkaline substance-containing layer 23 includes lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, rubidium hydroxide, beryllium hydroxide, magnesium hydroxide, strontium hydroxide, barium hydroxide, Examples include lithium carbonate, magnesium carbonate, potassium carbonate, 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.

In particular, sodium carbonate, potassium carbonate, calcium carbonate, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide, tripotassium citrate, sodium citrate, calcium citrate, potassium hydrogencarbonate, which alone shows pH 8 or more, The use of potassium pyrophosphate, calcined calcium, potassium phosphate, and sodium tartrate is more preferable in that the content rate of the alkaline substance can be reduced and the cost can be reduced.

When gallic acid is used as the oxygen absorbing substance, it is preferable to use sodium carbonate as the alkaline substance.

The binder contained in the alkaline substance-containing layer 23 is not particularly limited, but a solvent system is preferable from the viewpoint of moisture resistance. Examples of the resin type include polyester type, polyurethane type, polyether type, acrylic type, epoxy type, vinyl chloride type, silicone type and rubber type agents. Further, considering the adhesiveness with the oxygen absorption layer 22, it is desirable to use the same binder as the oxygen absorption layer 22.

The addition amount of the alkaline substance contained in the alkaline substance-containing layer 23 may be 40 parts by mass to 100 parts by mass, and 50 parts by mass to 100 parts by mass with respect to 100 parts by mass of the oxygen absorbing substance contained in the oxygen absorbing layer 22. It may be part by mass. If the amount of the alkaline substance added is less than 40 parts by mass, the pH is not always sufficient to promote the oxygen absorption reaction in the oxygen absorbing substance such as gallic acid, and the oxygen absorbing amount may decrease. On the other hand, even if the addition amount of the alkaline substance exceeds 100 parts by mass and the pH increases, the increase in the oxygen absorption amount cannot be expected so much.

The alkaline substance-containing layer 23 may contain any additive known in the art, such as an adhesion promoter, a plasticizer, an antioxidant, a coloring agent, a filler, and an ultraviolet absorber, if necessary. Good.

The thickness of the alkaline substance-containing layer 23 may be, for example, 0.1 μm or more and 20 μm or less. By having the film thickness within this range, good adhesion strength and strength of the coating layer itself can be obtained.

(Layer containing silane coupling agent)
As described in detail above, the laminate according to this embodiment includes at least one silane coupling agent-containing layer, and preferably has at least two silane coupling agent-containing layers.

As the silane coupling agent contained in the laminate according to the present embodiment, it is possible to use a known compound, for example, an epoxy silane coupling agent, an isocyanate silane coupling agent, an amine silane coupling agent and the like. Can be mentioned. In one embodiment, it is preferable to use a silane coupling agent having an organic functional group of the same type as the binder resin contained in the layer to which the silane coupling agent is added. For example, when the binder contained in the oxygen absorbing layer 22 or the anchor coat layer 21 is a polyurethane resin, it is preferable to use an isocyanate silane coupling agent.

In forming the silane coupling agent-containing layer, the method of adding the silane coupling agent to the coating liquid is not particularly limited. In order to further improve the adhesion strength between layers, a silane coupling agent is added to a base coating liquid composed of a binder resin and a solvent, and the binder resin and the silane coupling agent are reacted by stirring for a certain period of time before coating. Is desirable. Further, when the silane coupling agent-containing layer is an oxygen absorbing layer, it is desirable to add the oxygen absorbing substance after reacting the binder resin with the silane coupling agent. The addition amount of the silane coupling agent is not particularly limited and can be set as appropriate, but for example, the concentration of the coating liquid is preferably 0.1 to 3% by mass.

(Second outermost layer)
The laminated body 1 according to the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 2 includes a second outermost layer 30. The 2nd outermost layer 30 is a layer which constitutes the surface on the opposite side to the 1st outermost layer 10 as a substrate film in layered product 1.

When the laminated body 1 is used as a packaging material and is used in the form of a bag or the like, the second outermost layer 30 preferably includes a sealant layer. The sealant layer imparts heat sealability to the laminate 1. In this case, for example, the laminated body 1 can be easily processed into a bag shape by stacking the sheet run which is the second outermost layer 13 with the layers inside, and heat-sealing the peripheral edge portion.

As the sealant layer, a general-purpose thermoplastic resin may be used, and low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, polyethylene-vinyl acetate copolymer, amorphous polyester, cyclic polyolefin, etc. may be used. However, the resin is not particularly limited as long as it is a heat sealable resin.

<Package>
The packaging body according to the present embodiment includes the above laminated body. Specifically, at least a part of the package is formed of the above-mentioned laminated body. The packaging body according to the present embodiment may further include functional layers such as a printing layer, a barrier layer, and a surface protection layer.

Application examples 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. In addition, the bag-shaped package is formed by heating the peripheral portion of the two laminated bodies described above with the sealant layer serving as the second outermost layer 13 being arranged inside and bonding them together. May be. Furthermore, a so-called “gusset”-attached bag may be formed by interposing a third film on the peripheral edge portion for bonding.

The bag-shaped package may have any shape including a rectangle, a circle, and a triangle. Further, as the bag with a zipper, an opening and closing fitting portion may be provided in the opening of the bag-shaped package by machining.

<Packaged goods>
The packaged article according to the present embodiment includes the above package and the contents contained in the package. 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 assets. In the packaged article according to the present embodiment, when the content contained in the package is a food, the food may be a food with high water activity. Foods with high water activity include, for example, flour with water activity 0.8 to 0.87, rice, beans, fruit cake, etc., dried shirasu with water activity 0.87 to 0.91, salt salmon, sponge cake, etc. Examples include cheese with 0.91 to 0.95, fruit juice and the like, meat with water activity of 0.95 to 1.0, ham, bacon, sausage, fresh fish, eggs, fruits and the like.

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

<Example 1>
A polyester film (thickness 12 μm) having a silicon oxide vapor deposition layer was used as a base film having an oxygen barrier property. A coating agent containing tetraethylorthosilicate (TEOS) and polyvinyl alcohol as main components was gravure coated on the vapor deposition layer to form an overcoat layer (film thickness 1 μm).
On the overcoat layer (hereinafter, referred to as “OC layer”), a polyurethane-based anchor coating agent to which a silane coupling agent having an isocyanate group as an organic functional group is added is gravure-coated to form an anchor coat layer (hereinafter, This is referred to as “AC layer”) (film thickness 1 μm). The content of the silane coupling agent in the AC layer was 1% by mass based on the total mass of the AC layer.

Then, a composition obtained by adding gallic acid to a urethane-based binder and the same silane coupling agent as the silane coupling agent added to the AC layer is gravure-coated on the AC layer to form an oxygen film having a thickness of 5 μm. An absorption layer was formed. The content rate of gallic acid was 30 mass% and the content rate of the silane coupling agent was 1 mass% based on the total mass of the oxygen absorption layer.

Further, a composition obtained by adding sodium carbonate to a urethane-based binder was gravure coated on the oxygen absorbing layer to form an alkaline substance-containing layer having a film thickness of 5 μm. The content rate of sodium carbonate based on the total mass of the alkaline substance-containing layer was 30 mass %.

Then, a urethane adhesive was gravure-coated on the alkaline substance-containing layer, and a polyethylene film (film thickness 60 μm) was attached as a sealant layer to the oxygen-absorbing film 1a. The oxygen absorbing film 1a contains a silane coupling agent in the AC layer and the oxygen absorbing layer.

<Example 2>
As a base film having an oxygen barrier property, a polyester film (thickness 12 μm) having a silicon oxide vapor deposition layer was prepared. On the vapor-deposited layer, a coating agent containing tetraethylorthosilicate (TEOS) and polyvinyl alcohol as a main component and a silane coupling agent having an isocyanate group as an organic functional group was added by gravure coating to form an overcoat layer ( A film thickness of 1 μm) was formed. The content of the silane coupling agent in the OC layer was 1% by mass with respect to the total mass of the OC layer.

Then, a composition obtained by adding gallic acid to the urethane-based binder and the same silane coupling agent as the silane coupling agent added to the OC layer is gravure coated on the OC layer to form a film having a thickness of 5 μm. An oxygen absorption layer was formed. The content rate of gallic acid was 30 mass% and the content rate of the silane coupling agent was 1 mass% based on the total mass of the oxygen absorption layer.

Further, a composition obtained by adding sodium carbonate to a urethane-based binder was gravure coated on the oxygen absorbing layer to form an alkaline substance-containing layer having a film thickness of 5 μm. The content rate of sodium carbonate based on the total mass of the alkaline substance-containing layer was 30 mass %.

Then, a urethane adhesive was gravure-coated on the above-mentioned alkaline substance-containing layer, and a polyethylene film (film thickness 60 μm) as a sealant layer was adhered thereto to prepare an oxygen absorbing film 1b. The oxygen absorbing film 1b contains a silane coupling agent in the oxygen absorbing layer and the OC layer.

<Example 3>
An oxygen absorbing film 1c was produced under the same conditions and procedures as in Example 1, except that the content of gallic acid added to the oxygen absorbing layer was changed to 50% by mass. The oxygen absorption film 1c contains a silane coupling agent in the AC layer and the oxygen absorption layer.

<Example 4>
An oxygen absorbing film 1d was produced under the same conditions and procedures as in Example 1 except that the silane coupling agent was not added in the formation of the oxygen absorbing layer. The oxygen absorbing film 1d contains a silane coupling agent only in the AC layer.

<Example 5>
An oxygen absorbing film 1e was produced under the same conditions and procedures as in Example 1, except that the content of gallic acid added to the oxygen absorbing layer was changed to 60% by mass. The oxygen absorbing film 1e contains a silane coupling agent in the AC layer and the oxygen absorbing layer.

<Comparative Example 1>
An oxygen absorbing film 1f was produced under the same conditions and procedures as in Example 1, except that the silane coupling agent was not added to either the AC layer or the oxygen absorbing layer. The oxygen absorption film 1f does not include a layer containing a silane coupling agent.

<Comparative example 2>
Oxygen absorbing film 1g was produced under the same conditions and procedures as in Example 1 except that the silane coupling agent was not added in forming the AC layer. The oxygen absorbing film 1g contains a silane coupling agent only in the oxygen absorbing layer.

<Comparative example 3>
An oxygen absorbing film 1h was produced under the same conditions and procedures as in Comparative Example 1 except that the content of gallic acid added to the oxygen absorbing layer was changed to 20% by mass. The oxygen absorbing film 1h does not include a layer containing a silane coupling agent.

<Comparative example 4>
An oxygen absorbing film 1i was produced under the same conditions and procedures as in Comparative Example 1 except that the content of gallic acid added to the oxygen absorbing layer was changed to 10% by mass. The oxygen absorbing film 1i does not include a layer containing a silane coupling agent.

<Comparative Example 5>
A control film 1j was produced under the same conditions and procedures as in Comparative Example 1 except that gallic acid was not added to the oxygen absorption layer.

<Evaluation method>
(Oxygen absorption performance)
With respect to each of the films 1a to 1j produced above, a packaging bag having overall dimensions of 10 cm in width and 10 cm in length was prepared, and 80 cc of air was injected into the bag. After storing for a certain period in a constant temperature bath of 50° C., the oxygen concentration was measured, and the oxygen absorption amount of each was confirmed from the difference from the initial oxygen concentration. The case where the residual oxygen content was 1% or less was evaluated as "A", the case where it was more than 20% and 20% or less was evaluated as "B", and the case where it was more than 20% was evaluated as "C". Table 1 shows the evaluation results of each laminate.

(Adhesion strength)
Each of the films 1a to 1j produced above was cut into a width of 15 mm and peeled at 90° C. at a speed of 300 mm/min using a tensile tester to evaluate the strength between the base material and the oxygen absorbing layer. "A" indicates that the base material is cut and shows a strong laminate strength, and "B" indicates that the adhesion strength of 3N or more is sufficient for practical use, 1N or more and 3N When the adhesion strength was less than practically no problem, the adhesion strength was evaluated as "C", and the adhesion strength of less than 1N where no adhesion or practical problems occurred was evaluated as "D". The evaluation results of each film are shown in Table 1.

In Examples 1 to 5, both oxygen absorption performance and laminate strength were good. Particularly, in Examples 1 to 3 in which the silane coupling agent was added to both the AC layer and the oxygen absorption layer or both the oxygen absorption layer and the OC layer, the gallic acid content was as high as 30% by mass or 50% by mass. In other words, the laminate strength was high so that the substrate was cut when the laminate strength was measured.

In Example 4 in which the silane coupling agent was added only to the AC layer, the substrate did not break, and the laminate strength was slightly reduced as compared with Examples 1 to 3, but practically sufficient strength was maintained.
Further, in Example 5 in which the compounding ratio of gallic acid was further increased to 60% by mass, the laminate strength was slightly reduced as compared with Examples 1 to 3, but practically sufficient strength was maintained.

On the other hand, in Comparative Example 1 in which the silane coupling agent was not added at all, when the compounding ratio of gallic acid was 30% by mass, the laminating strength was significantly reduced and almost no adhesion was observed.
Also, in Comparative Example 2 in which the silane coupling agent was not added to the AC layer adjacent to the vapor deposition layer, but only to the oxygen absorption layer, the laminate strength was significantly reduced as compared with Examples 1 to 5.

In Comparative Examples 3 and 4 in which the mixing ratio of gallic acid was reduced, the laminate strength was recovered as compared with Comparative Example 1 without adding the silane coupling agent, but the oxygen absorption performance was reduced. In Comparative Example 5 in which gallic acid was not added at all, of course, there was no oxygen absorption performance, but the laminate strength was sufficient.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified at the stage of implementation without departing from the spirit of the invention. Further, the respective embodiments may be appropriately combined and implemented, in which case the combined effects 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 features. 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 can be obtained, the structure in which the constituent elements are deleted can be extracted as the invention.

1 Laminate 10 First Outermost Layer 10a Substrate 10b Vapor Deposition Layer 10c Overcoat Layer 20 Intermediate Layer 21 Anchor Coat Layer 22 Oxygen Absorption Layer 23 Alkaline Substance-Containing Layer 30 Second Outermost Layer

Claims (17)

A laminate comprising a first outermost layer composed of two or more layers, an intermediate layer composed of two or more layers, and a second outermost layer composed of a single layer or two or more layers in this order. The outer layer includes a base material whose one main surface constitutes the outermost surface of the laminate, and a metal-containing layer adjacent to the intermediate layer, and the intermediate layer includes an oxygen absorbing layer containing an oxygen absorbing substance. And a laminate containing a silane coupling agent in a layer adjacent to the metal-containing layer. The laminate according to claim 1, wherein a layer containing a silane coupling agent adjacent to the metal-containing layer is the oxygen absorption layer. The laminate according to claim 2, wherein the metal-containing layer is a vapor deposition layer or an aluminum foil. The laminate according to claim 2, wherein the first outermost layer includes the base material, a vapor deposition layer or an aluminum foil, and an overcoat layer in this order, and the metal-containing layer is the overcoat layer. .. The laminate according to claim 4, wherein the overcoat layer further contains a silane coupling agent. The intermediate layer includes an anchor coat layer between the metal-containing layer and the oxygen absorbing layer, and the layer containing a silane coupling agent adjacent to the metal-containing layer is the anchor coat layer. The laminate described. The laminate according to claim 6, wherein the metal-containing layer is an overcoat layer, a vapor deposition layer or an aluminum foil. The laminate according to claim 6 or 7, wherein the oxygen absorbing layer further contains a silane coupling agent. The laminate according to any one of claims 1 to 8, which contains the oxygen absorbing substance in an amount of 20% by mass or more based on the total mass of the oxygen absorbing layer. At least one of the layers containing a silane coupling agent contains a polyurethane resin which is a reaction product of a polyol compound and an isocyanate compound, and contains a compound having an isocyanate functional group as the silane coupling agent. The laminated body according to any one of claims 1 to 9. The laminate according to any one of claims 1 to 10, 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 11, further comprising an alkaline substance-containing layer between the oxygen absorption layer and the second outermost layer. The laminate according to any one of claims 1 to 11, wherein the oxygen absorption layer further contains an alkaline substance. The laminate according to claim 12 or 13, which contains at least sodium carbonate as the alkaline substance. The laminate according to any one of claims 1 to 14, wherein the second outermost layer includes a sealant layer. A package comprising the laminate according to any one of claims 1 to 15. A packaged article comprising the package according to claim 16 and the contents contained in the package.