Sheets, laminates, packaging containers, and packaging

Abstract

The present invention provides sheets, laminates, packaging containers, and packaging bodies that suppress hydrogen generation during storage and can generate a sufficient amount of hydrogen even when the contents are solids with a low water content. [Solution] Sheet 1B is a sheet comprising a polyolefin resin, a desiccant, and a hydrogen generating agent, wherein Sheet 1B comprises a first layer 11 and a second layer 12 provided on one side of the first layer 11, the first layer 11 comprising a polyolefin resin and a desiccant, and the second layer 12 comprising a polyolefin resin and a hydrogen generating agent.

Description

[Technical Field]

[0001] The present invention relates to a sheet, a laminate, a packaging container, and a package containing contents in a packaging container. [Background technology]

[0002] Traditionally, attention has been focused on the efficacy of hydrogenation, such as the imparting of reducing properties to water or water-containing solids, and various hydrogen additives and hydrogenation methods have been proposed. For example, a container with a hydrogen generation function has been proposed that stably adds hydrogen to the liquid contents housed inside the container (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5914306 [Overview of the project] [Problems that the invention aims to solve]

[0004] Because these hydrogen-generating containers react to water vapor present in the air, hydrogen generation can occur even during storage before the contents are placed inside, sometimes leading to a decrease in the hydrogen-generating function over time. Furthermore, while the aforementioned hydrogen-generating container can generate a sufficient amount of hydrogen when the contents are liquid, it sometimes fails to generate enough hydrogen when the contents are solids with low water content.

[0005] Therefore, the present invention has been made in view of the above problems, and aims to provide a sheet, laminate, packaging container, and packaging body that suppress hydrogen generation during storage and can obtain a sufficient amount of hydrogen generation even when the contents are solids with a low water content. [Means for solving the problem]

[0006] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a laminate comprising a first layer containing a moisture absorbent and a second layer containing a hydrogen generator, and have completed the present invention. That is, the present invention provides the following. (1) A sheet containing a polyolefin resin, a moisture absorbent, and a hydrogen generator. (2) The sheet includes a first layer and a second layer provided on one surface side of the first layer, The first layer contains a polyolefin resin and a moisture absorbent, The second layer contains a polyolefin resin and a hydrogen generator, and the sheet of (1). (3) The sheet is provided on the side opposite to the first layer of the second layer, and further includes a third layer containing a polyolefin resin, and the sheet of (2). (4) The sheet of (2) further includes a barrier layer provided on the side opposite to the first layer of the second layer of the sheet. (5) The moisture absorbent is hydrotalcite, and the sheet of any one of (1) to (4). (6) A packaging container in which a storage portion is formed using the sheet of any one of (1) to (4). (7) A package in which contents are stored in the storage portion of the packaging container of (6). (8) The package of (7) in which the moisture content of the contents is 50% or more and 85% or less. (9) A base material layer, A transparent vapor deposition layer provided on one surface side of the base material layer, <Q000089>A sealant layer provided on the side opposite to the base material layer of the transparent vapor deposition layer, and the sealant layer contains a polyolefin resin, a moisture absorbent, and a hydrogen generator, and a laminate. (10) The sealant layer has at least a first layer and a second layer in this order, (10) The first layer contains a polyolefin resin and a moisture absorbent, The first layer contains a polyolefin resin and a moisture absorbent, The second layer contains a polyolefin-based resin and a hydrogen generator, and is provided on the side closer to the transparent vapor deposition layer than the first layer, the laminate of (9). (11) The sealant layer is provided on the side opposite to the first layer of the second layer, and further includes a third layer containing a polyolefin-based resin, the laminate of (10). (12) The moisture absorbent is hydrotalcite, the laminate of any one of (9) to (11). (13) A packaging container in which a storage portion is formed using the laminate of any one of (9) to (11). (14) A package in which the content is stored in the storage portion of the packaging container of (13). (15) The moisture content of the content is 50% or more and 85% or less, the package of (14). (16) An outer packaging container having barrier properties, and a sheet or an inner bag housed in the outer packaging container, The sheet contains a polyolefin-based resin, a moisture absorbent, and a hydrogen generator, The inner bag is a packaging container formed by the sheet. (17) The sheet, includes a first layer containing a polyolefin-based resin and a moisture absorbent, and a second layer provided on one surface side of the first layer and containing a polyolefin-based resin and a hydrogen generator, The inner bag is formed by the sheet, and the first layer of the sheet is disposed inside the second layer, the packaging container of (16). (18) The sheet is provided on the side opposite to the first layer of the second layer, and further includes a third layer containing a polyolefin-based resin, the packaging container of (17). (1) The moisture absorbent is hydrotalcite, the packaging container of (18). (20) A package in which the content is stored in the outer packaging container of any one of (16) to (19). (21) The moisture content of the content is 50% or more and 85% or less, the package of (20).

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a sheet, laminate, packaging container, and packaging body that suppress hydrogen generation during storage and can obtain a sufficient amount of hydrogen even if the contents are solids with a low water content. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the cross-sectional structure of a laminate according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram showing a packaging container made from a laminate according to the first embodiment of the present invention. [Figure 3] This is a schematic diagram showing the cross-sectional structure of a package containing contents in a packaging container made from a laminate according to the first embodiment of the present invention. [Figure 4] This is a schematic diagram showing the cross-sectional configuration of a sheet according to a second embodiment of the present invention. [Figure 5] This is a schematic diagram showing an outer container according to a second embodiment of the present invention. [Figure 6] This is a schematic diagram showing the cross-sectional configuration of a packaging body in which contents are contained together with a laminate in an outer container according to the second embodiment of the present invention. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the following description, the same or similar parts will be denoted by the same reference numerals, and redundant explanations may be omitted.

[0010] The sheet according to this embodiment is characterized by comprising a polyolefin resin, a desiccant, and a hydrogen generating agent. Another form of laminate comprises a base layer, a transparent vapor-deposited layer provided on one side of the base layer, and a sealant layer provided on the side of the transparent vapor-deposited layer opposite to the base layer, wherein the sealant layer comprises a polyolefin resin, a desiccant, and a hydrogen generating agent. Furthermore, the packaging container according to this embodiment comprises a barrier outer container and a sheet or inner bag housed in the outer container, wherein the sheet comprises a polyolefin resin, a desiccant, and a hydrogen generating agent, and the inner bag is formed from the sheet. These configurations suppress hydrogen generation during storage and allow for sufficient hydrogen generation even when the contents are solids with low water content.

[0011] (First Embodiment) First, a first embodiment of the present invention will be described. Figure 1 is a schematic diagram showing the cross-sectional structure of a laminate according to the first embodiment of the present invention. Figure 2 is a schematic diagram showing a packaging container made from a laminate according to the first embodiment of the present invention. Figure 3 is a schematic diagram showing the cross-sectional structure of a package containing contents in a packaging container made from a laminate according to the first embodiment of the present invention.

[0012] [Laminate 1] The laminate 1 is a multilayer sheet-like film used in a packaging container. In this embodiment, as shown in Figure 1, the laminate 1 has a sealant layer 10, an adhesive layer 22, a barrier layer 21, and a base layer 20 laminated in this order and is used in a packaging container 50 (see Figure 2, which will be described later). In this specification, "laminated in this order" means that the sealant layer 10, the adhesive layer 22, the barrier layer 21, and the base layer 20 are laminated in this order, and other layers may be laminated between these layers. In this embodiment, it is desirable that the laminate 1 be made transparent or semi-transparent from the viewpoint that the contents contained in the packaging container 50 can be seen from the outside, but it is not limited to this.

[0013] [Sealant layer 10] The sealant layer 10 is a heat-sealable layer that exhibits adhesive properties upon heating. In this embodiment, the sealant layer 10 is laminated in the following order from the base layer 20 side: third layer 13, second layer 12, and first layer 11. The first layer 11 is preferably formed directly on one surface of the second layer 12, but other functional layers may be provided between the first layer 11 and the second layer 12. Similarly, the third layer 13 is preferably formed directly on the other surface of the second layer 12, but other functional layers may be provided between the second layer 12 and the third layer 13.

[0014] <1st layer 11> The first layer 11 is the layer in the laminate 1 that is furthest from the base layer 20, and is the layer that constitutes the innermost surface of the packaging container 50 when the laminate 1 is used to form the packaging container 50 described later. The first layer 11 contains a polyolefin resin and a desiccant, and has the function of absorbing moisture such as water vapor in the surrounding environment of the laminate 1 (packaging container 50). There are no particular restrictions on the thickness of the first layer 11, but the lower limit is preferably 10 μm or more, and the upper limit is preferably 100 μm or less. If it is thinner than the above range, it is difficult to fully exhibit the water absorption effect, and if it is thicker than the above range, the water absorption effect does not improve much, and the rigidity of the laminate becomes too strong, making it difficult to use as a packaging material.

[0015] The desiccant contained in the first layer 11 is preferably included via a masterbatch formed by melt-blending with a polyolefin resin (thermoplastic resin). Specifically, it is preferable to prepare a masterbatch by melt-blending a hygroscopic agent with a polyolefin resin at a relatively high concentration, and then dry-blending the masterbatch with other components to achieve the desired concentration in the first layer 11. The polyolefin resins used in the melt blend may be one type or two or more types.

[0016] The content of the desiccant relative to the total amount of resin in the first layer 11 is preferably 20% by mass or more and 90% by mass or less, and more preferably 30% by mass or more and 70% by mass or less. The lower limit of the content of the desiccant relative to the total amount of resin in the first layer 11 is preferably 20% by mass or more, and more preferably 30% by mass or more. The upper limit of the content of the desiccant relative to the total amount of resin in the first layer 11 is preferably 90% by mass or less, and more preferably 70% by mass or less. Within the above ranges, it is easy to include a necessary and sufficient amount of desiccant in the first layer 11 in a dispersed state.

[0017] (Polyolefin resin) Specific examples of polyolefin resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methylmethacrylic acid copolymer, ethylene-propylene copolymer, and mixtures of these resins. Among the above, polyethylene-based resins are preferred, and among polyethylene-based resins, LDPE, LLDPE, general-purpose PE, PE-based copolymers, etc. are more preferred, with LLDPE being even more preferred.

[0018] (Desiccant) The desiccant preferably contains an inorganic desiccant and / or an organic desiccant.

[0019] (Inorganic desiccant) Inorganic desiccants are inorganic compounds that absorb moisture from gases or liquids, and preferably contain one or more selected from the group consisting of zeolites, activated clay, hydrotalcite, and metal-organic frameworks (MOFs). Other desiccants may also be used in combination.

[0020] In the present invention, it is preferable that the zeolite contains type A zeolite, type CHA zeolite, or type MFI zeolite. Here, the pore size is preferably 0.3 to 0.5 nm for type A zeolite, approximately 0.38 nm for type CHA zeolite, and approximately 0.55 nm for type MFI zeolite. The specific surface area of ​​MFI-type zeolite is 300-400 m². 2 A product containing 1g is preferable. The zeolites described above can absorb not only water, but also gases of a molecular size and specific surface area corresponding to their pore size. For example, CHA-type zeolites are excellent at adsorbing lower hydrocarbons and carbon dioxide, while MFI-type zeolites are excellent at adsorbing carbon dioxide, lower hydrocarbons, lower aldehydes, lower organic acids, and lower alcohols.

[0021] In this invention, activated clay is a type of clay obtained by heat-treating naturally occurring acid clay or bentonite, which mainly consists of montmorillonite, with sulfuric acid or hydrochloric acid, followed by washing with water and drying. It is porous, has a large specific surface area, and exhibits excellent adsorption properties. Activated clay with a large specific surface area is preferable, and there are no particular restrictions on the specific surface area, but a specific surface area of ​​50 to 400 m² is preferable. 2 It is readily available in a quantity of 4-7 nm with a pore size of 4-7 nm. The pH (5% suspension) is preferably 2.5-9, and more preferably 3-7.

[0022] In the present invention, the organometallic structure is preferably a salt composed of a metal ion and an organic ligand. The above-described metal-organic structures can have a porous structure with smaller pore diameters and a larger specific surface area compared to common activated carbon and zeolites.

[0023] Specific examples of the organometallic structure in the present invention include aluminum fumarate, zirconium fumarate, copper trimesate, aluminum trimesate, zirconium trimesate, iron trimesate, aluminum terephthalate, zirconium terephthalate, zinc 2-methylimidazole, magnesium formate, zinc benzene-1,3,5-tricarboxylate, zinc 2,6-naphthalene-dicarboxylate, aluminum aminobenzene-1,4-dicarboxylate, magnesium 2,5-dioxidebenzene-1,4-dicarboxylate, magnesium 4,4-dioxidebiphenyl-3,3-dicarboxylate), etc. One or more selected from these groups can be used.

[0024] The pore diameter of the organometallic structure is preferably 0.3 nm or more and 3.0 nm, and more preferably 0.3 nm or more and 2.0 nm or less. For example, the pore diameters of zinc 2-methylimidazole salts are 1.1 nm and 0.6 nm, copper trimesate is 0.90 nm or 0.3 nm and 0.5 nm, aluminum terephthalate is 0.8 nm and 0.5 nm, aluminum fumarate is 1.1 nm and 0.5 nm, aluminum trimesate is 0.7 nm and 0.6 nm, zirconium trimesate is 0.46 nm, 1.15 nm, and 1.8 nm, magnesium formate is 0.3 nm and 0.4 nm, and iron trimesate is 2.5 nm and 2.9 nm.

[0025] The specific surface area of the organometallic structure can be expressed by the BET specific surface area or the Langmuir specific surface area. In the case of the BET specific surface area, it is preferably 400 m 2 / g or more and 4000 m 2 / g or less, and more preferably 900 m 2 / g or more and 2100 m 2 / g or less. In the case of the Langmuir specific surface area, it is preferably 500 m 2 / g or more and 5000 m 2 / g or less, and more preferably 1200 m 2 / g or more and 2400 m 2 / g or less. For example, the BET specific surface area of copper trimesate is 1500 m 2 / g, aluminum terephthalate is 950m 2 / g, aluminum fumarate at 1000m 2 / g, aluminum trimesinate is 1100m 2 / g, zirconium trimecinate is 2060m 2 / g, magnesium formate at 400mg 2 / g, zinc benzene-1,3,5-tribenzoate is 3600mg 2 There are some that are / g. Langmuir specific surface area is, for example, 2000 m² for copper trimesinate. 2 / g, aluminum terephthalate 1500m 2 / g, aluminum fumarate 1200m 2 / g, aluminum trimesinate 1500m 2 / g, zirconium trimesinate is 2390mg 2 / g, magnesium formate at 500mg 2 / g, zinc benzene-1,3,5-tribenzoate is 5000m 2 There are some that are / g.

[0026] In the present invention, it is preferable to use one or more organometallic structures selected from the group consisting of copper trimesicate, aluminum terephthalate, aluminum fumarate, aluminum trimesicate, and zircon trimesicate. The above-mentioned organometallic structures can adsorb not only water but also gases of a molecular size and specific surface area corresponding to their pore size. For example, copper trimesicate is excellent at adsorbing lower hydrocarbons (especially methane) and carbon dioxide, aluminum terephthalate is excellent at adsorbing methane, water, and carbon dioxide, aluminum fumarate and zirconate trimesicate are excellent at adsorbing water, and aluminum trimesicate is excellent at adsorbing lower hydrocarbons (especially methane) and water.

[0027] The number-average particle size of the primary particles of the inorganic desiccant is preferably between 1 nm and 400 nm. It is difficult to obtain primary particles smaller than this range, and if they are larger than this range, it tends to be difficult to obtain transparency in the transparent water-absorbing film. Furthermore, since primary particles often aggregate to form secondary particles, it is preferable to use them after micronizing them by known grinding methods such as a jet mill, and it is preferable that the number-average particle diameter including secondary particles in the transparent absorbent film is 1 nm or more and 20 μm or less. Making it smaller than the above range is difficult because it is the lower limit of the number-average particle diameter of the primary particles, and if it is larger than the above range, it tends to be difficult to obtain transparency in the transparent absorbent film.

[0028] (Organic desiccant) The organic desiccant is an organic resin that absorbs moisture from gases or liquids, and preferably contains one or more selected from the group consisting of poly(meth)acrylic acid, alkali metal salts of poly(meth)acrylic acid, alkaline earth metal salts of poly(meth)acrylic acid, polyvinyl acetate, and polyvinyl alcohol. Other desiccants may also be used in combination.

[0029] In the present invention, poly(meth)acrylic acid is a polymer using acrylic acid and / or methacrylic acid monomers, and may be a copolymer with other monomers. Examples include acrylic acid polymers, methacrylic acid polymers, acrylic acid-methacrylic acid copolymers, acrylic acid-maleic acid copolymers, methacrylic acid-maleic acid copolymers, and acrylic acid-methacrylic acid-maleic acid copolymers.

[0030] In the present invention, an alkali metal salt of poly(meth)acrylic acid is a salt of poly(meth)acrylic acid and an alkali metal, obtained, for example, by treating the above-mentioned poly(meth)acrylic acid with alkali metal potassium earth hydroxide. Some or all of the carboxyl groups derived from (meth)acrylic acid may form the salt. Examples include sodium poly(meth)acrylate salts and lithium poly(meth)acrylate salts.

[0031] In the present invention, an alkaline earth metal salt of poly(meth)acrylic acid is a salt of poly(meth)acrylic acid and an alkaline earth metal hydroxide, obtained, for example, by treating the above-mentioned poly(meth)acrylic acid with an alkaline earth metal hydroxide. Some or all of the carboxyl groups derived from (meth)acrylic acid may form the salt. Examples include calcium poly(meth)acrylate salts.

[0032] In the present invention, polyvinyl acetate is a polymer of vinyl acetate monomer, and may also be a copolymer with other monomers.

[0033] In the present invention, polyvinyl alcohol is a polymer having a structure in which the vinyl groups of vinyl alcohol are polymerized, but it may also be obtained by saponifying the above-mentioned polyvinyl acetate. Some or all of the carboxyl groups derived from polyvinyl acetate may be saponified.

[0034] The refractive index of the organic desiccant is preferably 1.3 or higher and less than 2.0, and the absolute value of the difference between it and the refractive index of the heat-sealable resin is preferably 0 or higher and 1.0 or lower. If the refractive index is higher or lower than the above range, it is difficult to keep the refractive index difference with the heat-sealable resin within the above range, and if the refractive index difference is larger than the above range, it tends to be difficult to obtain transparency in the transparent water-absorbing film. In this invention, the refractive index is the value obtained by forming a film in accordance with JIS K 7142:2008 and measuring it with light of a wavelength of 589 nm using an Abbe refractometer.

[0035] The organic desiccant may or may not be miscible with the heat-sealable resin in the water-absorbing layer. If it is not miscible, it is preferable that it is dispersed in the heat-sealable resin in the form of fine particles with a number-average particle size of 30 μm or less.

[0036] <2nd layer 12> The second layer 12 is a layer positioned between the first layer 11 and the third layer 13. The second layer 12 contains a polyolefin resin and a hydrogen generating agent, and has the function of generating hydrogen in the surrounding environment of the laminate 1 (inside the container of the packaging container 50) upon contact with water or water vapor.

[0037] There are no particular restrictions on the thickness of the second layer 12, but the lower limit is preferably 1 μm or more, and the upper limit is preferably 2000 μm or less. This not only facilitates the uniform dispersion of the hydrogen generating agent, but also makes it easier to control the amount of hydrogen generated per unit time, the hydrogen generation time, etc., within the desired range. If the thickness of the second layer 12 is less than 1 μm, the amount of hydrogen generated per unit time may become excessively low, or the hydrogen generation time may become excessively short, which is undesirable. Also, if the thickness of the second layer 12 exceeds 2000 μm, it may become difficult to form it to a uniform thickness, which is undesirable.

[0038] Therefore, the thickness of the second layer 12 is more preferably in the range of 10 to 500 μm, and even more preferably in the range of 20 to 200 μm. The lower limit of the thickness of the second layer 12 is more preferably 10 or more, and even more preferably 20 or more. A thickness above the lower limit makes it easier to secure a sufficient amount of hydrogen generation. The upper limit of the thickness of the second layer 12 is more preferably 500 μm or less, and even more preferably 200 μm or less. A thickness below the upper limit suppresses the decrease in transparency due to the inclusion of the hydrogen generating agent.

[0039] (Polyolefin resin) The polyolefin resin included in the second layer 12 can be the same resin as the polyolefin resin in the first layer 11 described above.

[0040] (Hydrogen generating agent) While there are no particular restrictions on the type of hydrogen generating agent, it is preferable that it mainly consists of metallic magnesium such as magnesium hydride and / or magnesium oxide, or one of them. By using such a type of hydrogen generating agent, the amount of hydrogen generated per unit time and the hydrogen generation time can be easily controlled within a desired range. Furthermore, by adding at least one of the following to a portion of the hydrogen generating agent: metallic aluminum or hydrogen storage alloy, the amount of hydrogen generated per unit time, the hydrogen generation time, and so on can be adjusted. Furthermore, by coating particulate hydrogen generating agents such as metallic magnesium and magnesium oxide with resin or ceramic, it is possible to control the reactivity of the hydrogen generating agent with water-containing substances such as liquids, and to effectively prevent the aggregation of the hydrogen generating agent.

[0041] Furthermore, the hydrogen generating agent content relative to the total amount of resin in the second layer 12 is preferably 1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 20% by mass or less. The lower limit of the hydrogen generating agent content relative to the total amount of resin in the second layer 12 is preferably 1% by mass or more, and more preferably 2% by mass or more. The upper limit of the hydrogen generating agent content relative to the total amount of resin in the second layer 12 is preferably 50% by mass or less, and more preferably 20% by mass or less. By controlling the hydrogen generating agent content in this way, the amount of hydrogen generated per unit time and the hydrogen generation time can be easily controlled within a desired range. If the hydrogen generating agent content is less than 1% by mass, the amount of hydrogen generated per unit time may become excessively low, or the hydrogen generation time may become excessively short, which is undesirable. Furthermore, if the hydrogen generating agent content exceeds 50% by mass, it may become difficult to uniformly disperse the hydrogen generating agent in the second layer 12, difficult to form it to a uniform thickness, and may even become prone to peeling from other layers, which is also undesirable.

[0042] Furthermore, the hydrogen generating agent is preferably granular, with a lower limit of average particle size of 0.1 μm or more, and a higher limit of average particle size of 200 μm or less. By controlling the average particle size of the hydrogen generating agent in this way, not only is uniform dispersion of the hydrogen generating agent facilitated, but the amount of hydrogen generated per unit time, the hydrogen generation time, etc., can be more easily controlled within the desired range. If the average particle size of the hydrogen generating agent is less than 0.1 μm, it may result in an excessively low amount of hydrogen generated per unit time or an excessively short hydrogen generation time, which is undesirable. Furthermore, if the average particle size of the hydrogen generating agent exceeds 200 μm, it becomes difficult to uniformly disperse it in the second layer 12, difficult to form it to a uniform thickness, and the second layer 12 may even become prone to peeling from adjacent layers, which is undesirable. Therefore, the lower limit of the average particle size of the hydrogen generating agent is more preferably 5 μm or more, and even more preferably 10 μm or more. The upper limit of the average particle size of the hydrogen generating agent is more preferably 100 μm or less, and even more preferably 50 μm or less. The average particle size of the hydrogen generating agent can be measured using an optical microscope or image processing system in accordance with JIS Z8901.

[0043] (water soluble material) Furthermore, the second layer 12 may further contain at least one of a phosphate glass, a borosilicate glass, a carbonate compound, and a sulfite compound as a water-soluble material. By further including a water-soluble material (a slightly water-soluble material) that dissolves gradually upon contact with water, pores are created inside the second layer 12, making it easier for moisture to penetrate, and consequently, the amount of hydrogen generated per unit time, the hydrogen generation time, etc., can be more easily controlled within a desired range over a long period of time.

[0044] Furthermore, when incorporating water-soluble materials, it is preferable to set the amount to be within the range of 1 to 100 parts by weight per 100 parts by weight of resin. By using such an amount of water-soluble material, the amount of hydrogen generated per unit time, the hydrogen generation time, etc., can be more easily controlled within the desired range. If the amount of water-soluble material added is less than 1 part by weight, it may result in an excessively low amount of hydrogen generated per unit time, or an excessively short hydrogen generation time, which is undesirable. Furthermore, if the amount of water-soluble material exceeds 100 parts by weight, it becomes difficult to uniformly disperse it in the hydrogen generation layer, difficult to form the second layer 12 to a uniform thickness, and the second layer 12 may become more prone to peeling off from other adjacent layers, which is undesirable. Therefore, it is more preferable to include the water-soluble material in an amount within the range of 10 to 80 parts by weight per 100 parts by weight of resin, and even more preferable to include it in an amount within the range of 20 to 70 parts by weight.

[0045] (Other additives) Preferably, the second layer 12 further contains at least one of the following additives: an adhesive, a colorant, an ultraviolet absorber, an antioxidant, a viscosity modifier, and an antistatic agent. By incorporating such additives, the functionality of the hydrogen generation layer can be further enhanced or improved.

[0046] <3rd layer 13> The third layer 13 is the layer that makes up the sealant layer 10 and is located closest to the base material layer 20. The third layer 13 contains a polyolefin resin and is formed on the side of the second layer 12 opposite to the first layer 11. In this embodiment, the sealant layer 10 is manufactured by co-extruding three layers: the resin forming the first layer 11, the resin forming the second layer 12, and the resin forming the third layer 13. If the thicknesses of the first layer 11 and the second layer 12 differ, this difference in thickness may cause warping of the sealant layer. However, by providing a third layer 13 with the same thickness as the first layer 11, it is possible to suppress the occurrence of the aforementioned warping of the sealant layer 10. Furthermore, the third layer 13 can also suppress hydrogen generated from the hydrogen generating agent contained in the second layer 12 from escaping to the substrate layer 20, and can also suppress the hydrogen generating agent contained in the second layer 12 from falling off the second layer. The third layer 13 may be omitted if necessary. The polyolefin resin included in the third layer 13 can be the same resin as the polyolefin resin in the first layer 11 described above.

[0047] In this embodiment, the sealant layer 10 was described as having a multilayer structure comprising a first layer 11, a second layer 12, and a third layer 13. However, it is not limited to this, and for example, the sealant layer may be a single-layer structure containing a polyolefin resin, a desiccant, and a hydrogen generating agent.

[0048] [Base material layer 20] The base layer 20 is mainly a layer containing resin. The resin is not particularly limited, and known resin films or sheets can be used. For example, resin films containing polyester resins such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin, or polyamide resins; or polyolefin resins such as polymers or copolymers of α-olefins such as polyethylene and polypropylene can be used.

[0049] Among these resins, polyester resins are preferably used, and among polyester resins, polyethylene terephthalate resins or polybutylene terephthalate resins are preferable. In particular, when heat sealing is required or when a printed layer is to be provided, polyethylene terephthalate resin is preferably used as the base layer 20. Furthermore, if it is desired to provide puncture resistance to the laminate 1, a polyamide resin is preferably used as the base layer 20.

[0050] The base layer 20 may be a single layer or a multilayer structure of two or more layers. In the case of a multilayer structure, the layers may have the same composition or different compositions. In the case of a multilayer structure, the layers may be bonded together with an adhesive layer or the like interposed between them.

[0051] The thickness of the base layer 20 is not particularly limited, but is preferably 5 μm or more and 25 μm or less, and more preferably 8 μm or more and 15 μm or less. The lower limit of the thickness of the base layer 20 is preferably 5 μm or more, and more preferably 8 μm or more. The upper limit of the thickness of the base layer 20 is preferably 25 μm or less, and more preferably 15 μm or less. A thickness of 5 μm or more for the base layer 20 can make the strength of the laminate 1 desirable. A thickness of 25 μm or less allows the overall thickness of the laminate 1 to be reduced, and if the laminate 1 is transparent, the transparency increases, improving the visibility of the contents.

[0052] [Barrier layer 21] The barrier layer 21 is a layer that suppresses the permeation of gases such as water vapor. The barrier layer 21 can significantly suppress the diffusion of hydrogen gas generated from the second layer 12 towards the base layer 20, so it is preferable to provide the barrier layer 21 in the laminate 1. It is preferable that the barrier layer 21 is a layer formed directly on one side of the base layer 20, or on one side of the anchor coat layer if an anchor coat layer is provided.

[0053] The barrier layer 21 may be, for example, a metal vapor-deposited film formed by depositing a metal, or a vapor-deposited film formed by depositing an inorganic compound. In this specification, a layer formed by depositing such an inorganic material is referred to as an inorganic vapor-deposited layer.

[0054] Examples of metals that can be used to make up a metal vapor-deposited film include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Among these, aluminum is preferred. In other words, an aluminum vapor-deposited film is preferred.

[0055] Examples of inorganic compounds constituting the above-mentioned deposited film include metal oxides, metal nitrides and metal carbides, indium tin oxide (ITO), and SiO2. X C Y Examples of complex inorganic compounds include those listed above. Among these, metal oxides are preferred. Furthermore, if the laminate 1 is required to be transparent or semi-transparent, the barrier layer 21 is preferably a vapor-deposited film (transparent vapor-deposited layer) composed of an inorganic compound such as a metal oxide.

[0056] Examples of metallic elements that make up inorganic compounds include aluminum (Al), silicon (Si), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), zinc (Zn), vanadium (V), barium (Ba), and chromium (Cr).

[0057] The average composition of inorganic compounds is, for example, AlO x SiO x SiO x C y For example, MO x or MO x C y This is expressed as follows: In the formula, M represents the metal element mentioned above, and the values ​​of x and y differ in range depending on the metal element.

[0058] Among metal oxides, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, boron oxide, titanium oxide, zirconium oxide, and barium oxide are preferred, with aluminum oxide and silicon oxide being more preferred.

[0059] The inorganic vapor deposition layer may be formed from one metal or inorganic compound, or from a combination of two or more metals or inorganic compounds. The inorganic vapor deposition layer may consist of a single layer, or it may consist of two or more layers of the same or different compositions. Furthermore, the inorganic vapor deposition layer may be combined with the organic coating layer described later.

[0060] When the inorganic vapor deposition layer is multilayered, each layer can be deposited to have high barrier properties, thus achieving even higher barrier properties than a single layer. If the inorganic vapor deposition layer is multilayered and each layer has a different composition, the inorganic vapor deposition layer becomes a discontinuous layer, allowing for more efficient suppression of the permeation of oxygen gas, water vapor, and other elements.

[0061] When an inorganic vapor-deposited layer is laminated as the barrier layer 21, the thickness of the inorganic vapor-deposited layer is preferably 3 nm to 300 nm, more preferably 4 nm to 250 nm, and even more preferably 5 nm to 200 nm. The lower limit of the thickness of the inorganic vapor-deposited layer is preferably 3 nm or more, more preferably 4 nm or more, and even more preferably 5 nm or more. The upper limit of the thickness of the inorganic vapor-deposited layer is preferably 300 nm or less, more preferably 250 nm or less, and even more preferably 200 nm or less. If the thickness is above the lower limit, for example, sufficient barrier properties can be obtained. If the thickness is below the upper limit, for example, the occurrence of cracks in the inorganic vapor-deposited layer can be suppressed.

[0062] Furthermore, the barrier layer 21 may be an organic coating layer formed by applying a coating agent containing a water-soluble polymer such as polyvinyl alcohol. The organic coating layer is formed by applying a coating solution containing, for example, a water-soluble polymer and an aqueous solution or water / alcohol mixed solution containing at least one of one of a water-soluble polymer, one or more metal alkoxides and hydrolysates, or tin chloride. These may be formed on the inorganic vapor-deposited layer described above. In addition, EVOH (ethylene vinyl alcohol copolymer resin) or MXD nylon can also be used as the barrier layer 21.

[0063] [Adhesive layer 22] In one embodiment, the laminate 1 of the present invention includes an adhesive layer 22 between the sealant layer 10 and the barrier layer 21. The adhesive layer 22 is a layer for bonding the barrier layer 21, which is provided on one side of the base layer 20, to the sealant layer 10.

[0064] In this embodiment, the adhesive layer 22 protects the barrier layer 21. For example, when a bending load is applied to the laminate 1, the adhesive layer 22 suppresses the occurrence of cracks in the barrier layer 21, and even if minute cracks begin to appear in the barrier layer 21 after the bending load, it suppresses a decrease in barrier properties.

[0065] The thickness of the adhesive layer 22 is not particularly limited, but is preferably 0.5 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less. The lower limit of the thickness of the adhesive layer 22 is preferably 0.5 μm or more, more preferably 1 μm or more. The upper limit of the thickness of the adhesive layer 22 is preferably 20 μm or less, more preferably 10 μm or less. Furthermore, the amount of adhesive layer 22 applied is not particularly limited, but preferably 1 g / m² 2 More than 20g / m 2 More preferably 2 g / m 2 More than 15g / m 2 The following applies: The lower limit of the amount of adhesive layer 22 applied is preferably 1 g / m². 2 More than 2g / m 2That concludes the explanation. The upper limit of the amount of adhesive layer 22 applied is preferably 20 g / m². 2 More preferably 15g / m 2 The following applies:

[0066] The adhesive layer 22 can be formed using a conventionally known adhesive. The adhesive may be a one-component curing type, a two-component curing type, or a non-curing type adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive. The adhesive layer 22 may be formed, for example, by a non-solvent lamination method using a non-solvent adhesive, or by a dry lamination method using a dry lamination adhesive. An anchor coat layer may be formed first on the layer on which the adhesive layer 22 is formed, and then the adhesive layer 22 may be formed.

[0067] [Other layers] The laminate 1 of this embodiment may further include other functional layers in addition to the layers described above. For example, a biaxially oriented nylon (ONY) film with excellent toughness and heat resistance may be placed between the barrier layer and the sealant layer to improve the toughness and heat resistance of the laminate 1. [Method for manufacturing laminate 1] The laminate 1 can be manufactured, for example, as follows. First, a base layer 20 is prepared, and a barrier layer 21 is formed by depositing an inorganic compound or the like onto one side of the base layer 20 to create an intermediate laminate. Next, a sealant layer 10 is produced by co-extruding three layers: a polyolefin resin containing a hygroscopic agent to form the first layer 11, a polyolefin resin containing a hydrogen generating agent to form the second layer 12, and a polyolefin resin to form the third layer 13. Next, the laminate 1 shown in Figure 1 is completed by bonding the third layer 13 side of the fabricated sealant layer 10 to the barrier layer 21 side of the intermediate laminate via the adhesive layer 22.

[0068] [Example of the configuration of laminate 1] The laminate 1 of this embodiment can be constructed, for example, with the following layer configuration. Note that the laminate 1 is described using a slash ( / ) between each layer. • Biaxially oriented polyethylene terephthalate (PET) resin film 12μm / Transparent vapor deposition layer / Adhesive layer / LDPE 10μm / LDPE (containing hydrogen generating agent) 30μm / LDPE (containing moisture absorbent) 10μm • Biaxially oriented polyethylene terephthalate (PET) resin film 12μm / Transparent vapor deposition layer / Adhesive layer / LDPE (containing hydrogen generating agent) 30μm / LDPE (containing moisture absorbent) 10μm • Biaxially oriented polyethylene terephthalate (PET) resin film 12μm / transparent vapor deposition layer / adhesive layer / Biaxially oriented nylon (ONY) film 15μm / adhesive layer / LDPE 10μm / LDPE (containing hydrogen generating agent) 30μm / LDPE (containing moisture absorber) 10μm • Biaxially oriented polyethylene terephthalate (PET) resin film 12μm / transparent vapor deposition layer / adhesive layer / Biaxially oriented nylon (ONY) film 15μm / adhesive layer / LDPE (containing hydrogen generating agent) 30μm / LDPE (containing moisture absorbent) 10μm

[0069] [Packaging container 50] The packaging container 50 is manufactured using the laminated body 1 described above. Specifically, as shown in Figure 2, the packaging container 50 is formed into a bag-like shape (three-sided pouch shape) with a storage compartment 53 by overlapping two rectangular laminated bodies 1 with the sealant layer 10 facing inward, and sealing the edges of three sides of the outer circumference by heat sealing to form a sealed portion 51. The remaining side of the outer circumference of the packaging container 50 is not heat-sealed and becomes an opening 52, which is used when storing contents in the storage compartment 53. Furthermore, the packaging container 50 is not limited to the three-sided pouch type described above, but may also be formed in a pillow-type or gusset-type form.

[0070] [Packaging 100: Packaging container containing the contents] The contents are placed into the packaging container 50 in the following manner. First, the opening 52 of the packaging container 50 is opened, and the contents P are placed in the storage section 53. Next, the opening 52 is sealed by heat sealing while the storage section 53 containing the contents P is evacuated. As a result, a sealed package 100 is completed, as shown in Figure 3. Here, the contents contained in the packaging container 50 may be not only liquids but also water-containing solids (such as seafood or meat). The laminate 1 constituting the packaging container 50 is formed with a first layer 11 containing a desiccant and a second layer 12 containing a hydrogen generating agent as separate layers. As a result, moisture contained in the contents is efficiently guided to the second layer 12, while moisture from the outside air is blocked by the first layer 11. In particular, even if the contents are low-moisture materials such as water-containing solids, it is possible to promote the utilization of moisture and reliably generate hydrogen with minimal moisture. Furthermore, the water content of water-containing solids varies depending on the type of seafood. For example, tuna has a water content of 50-78%, yellowtail 59%, young yellowtail 61%, sea bream 71-77%, salmon 62-70%, and scallops 75-82%. In the case of meat, beef, pork, and chicken all have a water content of 60-70%. Therefore, from the viewpoint of obtaining a sufficient amount of hydrogen generation, the water-containing solids contained in the packaging container 50 preferably have a water content of 50% to 85%, and more preferably 60% to 75%. The lower limit of the water content of water-containing solids is preferably 50% or more, and more preferably 60% or more. The upper limit of the water content of water-containing solids is preferably 85% or less, and more preferably 75% or less.

[0071] As described above, since the laminate 1 and the packaging container 50 formed from the laminate 1 have a first layer 11 containing a desiccant, it is possible to minimize the reaction of the hydrogen generating agent contained in the second layer 12 with water vapor present in the atmosphere to generate hydrogen during storage. Furthermore, by having a first layer containing a desiccant and a second layer containing a hydrogen generating agent, the laminate 1 and the packaging container 50 can obtain a sufficient amount of hydrogen even if the contents are solids with a low water content.

[0072] (Second Embodiment) Next, a second embodiment of the present invention will be described. Figure 4 is a schematic diagram showing the cross-sectional configuration of a sheet according to the second embodiment of the present invention. Figure 5 is a schematic diagram showing an outer container according to a second embodiment of the present invention. Figure 6 is a schematic diagram showing the cross-sectional configuration of a packaging body in which contents are contained together with a laminate in an outer container according to the second embodiment of the present invention.

[0073] [Packaging container 50B] The packaging container 50B of the second embodiment consists of an outer container 70 having barrier properties and a sheet 1B placed in the containment section 73 of the outer container 70. In this embodiment, the packaging container 50B can be filled with contents together with the sheet 1B in the containment section of the outer container 70, and then sealed after degassing the containment section, thereby obtaining a sufficient amount of hydrogen generation relative to the contents.

[0074] [Outer container 70] The outer container 70 is a container that has barrier properties to prevent the intrusion of water vapor, and in this embodiment, it is formed by an outer laminate 60. As shown in Figure 5(A), the outer laminate 60 is a barrier-type laminate in which, for example, an outer base material layer 61, an outer barrier layer 62, and an outer sealant layer 63 are laminated in this order. The outer substrate layer 61 can use the same substrate as the substrate layer 20 of the laminate 1 in the first embodiment described above. Furthermore, the outer barrier layer 62 can use the same barrier layer as the barrier layer 21 of the laminate 1 in the first embodiment described above. Furthermore, the exterior laminate 60 may also include other functional layers in addition to the layers described above. For example, a biaxially oriented nylon (ONY) film with excellent toughness and heat resistance may be placed between the exterior barrier layer and the outer sealant layer to improve the toughness and heat resistance of the exterior laminate 60.

[0075] The exterior sealant layer 63 is a heat-sealable layer that exhibits adhesive properties upon heating. The exterior sealant layer 63 can be formed using a conventionally known thermoplastic resin. Examples of thermoplastic resins that can be used include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, polyester resin, polyvinyl chloride resin, polystyrene resin, nylon, etc., or mixtures thereof. Low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and ethylene-methacrylic acid copolymer are more preferred.

[0076] The thickness of the exterior sealant layer 63 is not particularly limited, but is usually in the range of 10 μm to 100 μm, more preferably in the range of 20 μm to 60 μm, and even more preferably in the range of 25 μm to 50 μm. The lower limit of the thickness of the exterior sealant layer 63 is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. The upper limit of the thickness of the exterior sealant layer 63 is preferably 100 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less.

[0077] The exterior sealant layer 63 may be a single-layer structure or a multilayer structure consisting of multiple layers. In the case of a multilayer structure, for example, a two-layer structure can be provided in which a low-density polyethylene (LDPE) layer and a linear low-density polyethylene (LLDPE) layer are laminated in order from the exterior barrier layer 62 side.

[0078] The outer container 70 is manufactured using the outer laminate 60 described above. Specifically, as shown in Figure 5(B), the outer container 70 is formed into a bag-like shape (three-sided pouch shape) with a storage compartment 73 by overlapping two rectangular outer laminates 60 with the outer sealant layer 63 facing inward, and sealing the edges of three sides of the outer perimeter by heat compression to form a sealed portion 71. The remaining side of the outer perimeter of the outer container 70 is not heat-sealed and becomes an opening 72, which is used to store the contents in the storage compartment 73.

[0079] Furthermore, the form of the outer container 70 is not limited to the three-sided pouch type described above, but may also be formed in a pillow-type or gusset-type form. In addition, the outer container 70 can be not only in the bag-like form using the outer laminate 60 described above, but can also be a glass box-shaped container, a metal box-shaped container, or the like.

[0080] [Sheet 1B] Sheet 1B is a sheet-like film (sheet) that is housed together with the contents P in the housing section 73 of the outer container 70. Sheet 1B has a layer structure similar to the sealant layer 10 provided in the laminate 1 of the first embodiment described above. That is, as shown in Figure 4, Sheet 1B is laminated in the order of a first layer 11, a second layer 12, and a third layer 13. It is preferable that the first layer 11 be formed directly on one surface of the second layer 12, but other functional layers may be provided between the first layer 11 and the second layer 12. It is also preferable that the third layer 13 be formed directly on the other surface of the second layer 12, but other functional layers may be provided between the second layer 12 and the third layer 13. Note that the third layer 13 may be omitted if necessary. The details of the first layer 11, second layer 12, and third layer 13 constituting sheet 1B are the same as those of the first layer 11, second layer 12, and third layer 13 provided in the sealant layer 10 of the laminate 1 of the first embodiment described above. Furthermore, sheet 1B can be manufactured by the same method as the sealant layer 10 of the first embodiment described above.

[0081] In this embodiment, sheet 1B was described as having a multilayer structure comprising a first layer 11, a second layer 12, and a third layer 13. However, it is not limited to this, and for example, it may be a single-layer sheet containing a polyolefin resin, a desiccant, and a hydrogen generating agent. Furthermore, in addition to the layers described above, sheet 1B may also include other functional layers. For example, a barrier layer similar to the barrier layer 21 provided in the laminate 1 of the first embodiment may be provided on the side of the third layer 13 opposite to the second layer 12, or a biaxially oriented nylon (ONY) film with excellent toughness and heat resistance may be provided between the barrier layer and the third layer 13 to improve the toughness and heat resistance of sheet 1B.

[0082] [Packaging 110: Packaging container containing contents] The contents are placed into the packaging container 50B (outer container 70) as follows: First, the opening 72 of the outer container 70 is opened, and the contents P are placed in the storage section 73 together with the sheet 1B. Next, the opening 72 is sealed by heat sealing while the storage section 73 containing the contents P and sheet 1B is evacuated. As a result, as shown in Figure 6, a sealed package 110 containing the contents P and sheet 1B is completed. Here, the contents P contained in the packaging container 50B (outer container 70) may be not only liquids but also water-containing solids (such as seafood or meat). The sheet 1B constituting the packaging container 50B is formed with a first layer 11 containing a desiccant and a second layer 12 containing a hydrogen generating agent as separate layers. As a result, moisture contained in the contents is efficiently guided to the second layer 12, while moisture from the outside air is blocked by the first layer 11. In particular, even if the contents are made of a low-moisture material such as a water-containing solid, it is possible to promote the utilization of moisture and reliably generate hydrogen with a minimum amount of moisture. Furthermore, the solid contents contained in the packaging container 50B (outer container 70) preferably have a water content of 50% to 85%, and more preferably 60% to 75%, from the viewpoint of obtaining a sufficient amount of hydrogen generation. The lower limit of the water content of the water-containing solid is preferably 50% or more, and more preferably 60% or more. The upper limit of the water content of the water-containing solid is preferably 85% or less, and more preferably 75% or less.

[0083] In this embodiment, the packaging 110 is described as being sealed by placing the sheet 1B together with the contents P in the storage section 73 of the outer container 70, but it is not limited to this. For example, two rectangular sheets 1B may be overlapped so that the outer sealant layer 63 is on the inside, and the edges of three sides of the outer circumference may be sealed by heat pressing to form a bag shape (three-sided pouch shape) to form an inner bag, the contents P may be placed in the inner bag, and the inner bag together may be placed in the storage section 73 of the outer container 70 and sealed to form the packaging 110.

[0084] As described above, since the packaging container 50B (sheet 1B) has a first layer 11 containing a desiccant, it is possible to minimize the reaction of the hydrogen generating agent contained in the second layer 12 with water vapor present in the atmosphere to generate hydrogen during storage. Furthermore, by having a first layer containing a desiccant and a second layer containing a hydrogen generating agent, the packaging container 50B (sheet 1B) can generate a sufficient amount of hydrogen within the storage section 73 of the outer container 70, even if the contents are solids with a low moisture content. [Examples]

[0085] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. First, we will explain the fabrication of the laminates of the examples and comparative examples, and the outer containers that house the laminates together with their contents. In the following evaluation, the sheet 1B was evaluated based on the packaging container 50B of the second embodiment described above. However, since the laminate 1 and packaging container 50 of the first embodiment also have a first layer 11 containing a desiccant and a second layer 12 containing a hydrogen generating agent, similar evaluation results can be expected.

[0086] <Preparation of the sheet for Example 1> A sheet with a total thickness of 50 μm (corresponding to sheet 1B) was obtained by co-extruding three layers, with an LDPE resin layer (corresponding to the third layer 13) being 10 μm thick, an LDPE resin layer containing magnesium hydride as a hydrogen generating agent (corresponding to the second layer 12) being 30 μm thick, and an LDPE resin layer containing hydrotalcite as a desiccant (corresponding to the first layer 11) being 10 μm thick. Here, the hydrogen generating agent content relative to the total resin amount of the LDPE resin layer corresponding to the second layer 12 is 3% by mass. In addition, the desiccant content relative to the total resin amount of the LDPE resin layer corresponding to the first layer 11 is 40% by mass.

[0087] <Preparation of the sheet for Comparative Example 1> A sheet with a layer thickness of 50 μm was obtained by co-extruding three layers, with a 10 μm layer of LDPE resin, a 30 μm layer of LDPE resin containing magnesium hydride as a hydrogen generating agent, and a 10 μm layer of LDPE resin. Here, the hydrogen generating agent content relative to the total resin amount of the LDPE resin layer containing the hydrogen generating agent is 3% by mass.

[0088] <Manufacturing of outer packaging> The outer container is a barrier container (corresponding to outer container 70) that contains the contents together with the sheets of the above-described examples and comparative examples. A 12 μm thick transparent vapor-deposited film (IBPET-PBIR, manufactured by Dai Nippon Printing Co., Ltd.) is prepared, in which a vapor-deposited film of an inorganic compound (corresponding to the outer barrier layer 62) is formed on one side of a polyethylene terephthalate (PET) resin film (corresponding to the outer substrate layer 61). Adhesive (RU-004 / H-1, manufactured by Rock Paint Co., Ltd.) is applied to the vapor-deposited film side of the prepared transparent vapor-deposited film to a thickness of 3 μm, and a 15 μm thick biaxially oriented nylon (ONY) film (Bonel W, manufactured by Kojin Film & Chemicals Co., Ltd.) is laminated to it. Next, adhesive (RU-004 / H-1, manufactured by Rock Paint Co., Ltd.) is applied to the side of the biaxially oriented nylon (ONY) film opposite to the transparent vapor-deposited film to a thickness of 3 μm, and a 60 μm thick unoriented polypropylene (CPP) film (ZK207, manufactured by Toray Film Processing Co., Ltd., corresponding to the outer sealant layer 63) is laminated to it to obtain a laminate (corresponding to the outer laminate 60) to be used for the outer container. Two rectangular laminates (corresponding to the outer laminate 60) are overlapped so that the sealant layer faces inward, and the edges of three sides of the outer perimeter are sealed by heat compression to form a bag-like structure (three-sided pouch) with a storage compartment, thereby obtaining an outer container.

[0089] [Evaluation of hydrogen generation when water-containing solids are included as contents] Each of the laminates from the examples and comparative examples was placed in an outer container along with its contents, which were water-containing solids, and the amount of hydrogen generated in each was evaluated. Specifically, first, the sheets of the example and comparative example were each cut into 10 cm square films, and a 5 cm square piece of cotton (corresponding to the contents simulating a water-containing solid) was attached to each cut film. The cotton was moistened with 1.8 mL of water and placed in a 20 cm square barrier outer container (corresponding to outer container 70), which was then sealed under vacuum. In this state, it was stored for 9 days at 23 degrees Celsius, and before measurement, 800 mL of air was placed in the outer bag, and the hydrogen concentration was measured using a detector tube (manufactured by Komei Rika Kagaku Kogyo Co., Ltd., model number 137U). The amount of hydrogen generated (mL) was calculated from the measured hydrogen concentration and summarized in Table 1. Note that the hydrogen generation amounts in Table 1 are the average of the measurement results from two test pieces each for the examples and comparative examples. The water content of the water-moistened cotton was 60%.

[0090] [Table 1]

[0091] As shown in Table 1, the amount of hydrogen generated in the outer container was 4.08 mL in the comparative example, while it was 4.96 mL in the example, representing about a 20% increase in hydrogen generation compared to the comparative example. This confirms that the sheet in the example is formed with a resin layer containing a desiccant and a resin layer containing a hydrogen generating agent as separate layers, and that even if the contents are low-moisture materials such as water-containing solids, it promotes the utilization of moisture and can reliably generate hydrogen with minimal moisture.

[0092] In this evaluation, a similar evaluation was performed using an outer container without barrier properties, but in both the examples and comparative examples, the hydrogen concentration inside the outer container was zero (zero hydrogen generation). This is presumed to be because the hydrogen generated from the sheets in the examples and comparative examples permeated through the outer container without barrier properties and was discharged to the outside. As outer containers without barrier properties, an outer container made of 50 μm thick LDPE film and an outer container made of a film laminated with a 15 μm thick biaxially oriented nylon (ONY) film and a 60 μm thick unoriented polypropylene (CPP) film were used.

[0093] [Evaluation of hydrogen generation under storage conditions] For each of the sheets in the examples and comparative examples, the amount of hydrogen generated under storage conditions was evaluated. First, the sheets for the examples and comparative examples were each cut into 10 cm square films and placed in a 20 cm square barrier outer container (equivalent to outer container 70), with 300 mL of air added and sealed. In this state, they were stored for 9 days at 23 degrees Celsius, and the hydrogen concentration was measured using a detector tube (manufactured by Komei Rika Kagaku Kogyo Co., Ltd., model number 137U). The measured hydrogen concentrations were converted to hydrogen generation amounts (mL) and summarized in Table 2.

[0094] [Table 2]

[0095] As shown in Table 2, the amount of hydrogen generated in the outer container was 1.92 mL in the comparative example, while it was 0.15 mL in the example, which was less than one-tenth the amount of hydrogen generated in the comparative example. This confirms that, during storage for 9 days in an environment of 23 degrees Celsius, which simulates storage conditions, the sheet of the example, having a resin layer containing a desiccant (corresponding to the first layer 11), was able to suppress the reaction of the hydrogen generating agent with moisture contained in the air inside the outer container as much as possible compared to the sheet of the comparative example. [Explanation of Symbols]

[0096] 1. Laminate 1B Sheet 10. Sealant layer 11 1st layer 12 2nd layer 13 3rd layer 20 Base material layer 21 Barrier layer 22 Adhesive layer 50, 50B packaging container 60 Exterior laminate 70 Outer container 100, 110 packaging

Claims

1. A sheet comprising a polyolefin resin, a desiccant, and a hydrogen generating agent, The sheet comprises a first layer and a second layer provided on one side of the first layer. The first layer comprises a polyolefin resin and a desiccant. The second layer is a sheet containing a polyolefin resin and a hydrogen generating agent.

2. The sheet further comprises a third layer containing a polyolefin resin, provided on the side of the second layer opposite to the first layer. The sheet according to claim 1.

3. The sheet further comprises a barrier layer provided on the side of the second layer opposite to the first layer. The sheet according to claim 1.

4. The sheet according to any one of claims 1 to 3, wherein the desiccant is hydrotalcite.

5. A packaging container having a storage section formed using the sheet described in any one of claims 1 to 3.

6. A package in which contents are contained in the storage portion of the packaging container according to claim 5.

7. The packaging according to claim 6, wherein the moisture content of the contents is 50% or more and 85% or less.

8. A base layer and A transparent vapor-deposited layer provided on one side of the substrate layer, The transparent vapor deposition layer comprises a sealant layer provided on the side opposite to the substrate layer, The sealant layer comprises a polyolefin resin, a desiccant, and a hydrogen generator. The sealant layer comprises at least a first layer and a second layer in this order. The first layer comprises a polyolefin resin and a desiccant. The second layer comprises a polyolefin resin and a hydrogen generating agent, and is provided on the transparent vapor deposition layer side of the first layer.

9. The laminate according to claim 8, wherein the sealant layer is provided on the side of the second layer opposite to the first layer and further comprises a third layer containing a polyolefin resin.

10. The laminate according to claim 8 or 9, wherein the desiccant is hydrotalcite.

11. A packaging container having a storage section formed using the laminate described in claim 8 or claim 9.

12. A package in which contents are contained in the storage portion of the packaging container according to claim 11.

13. The packaging according to claim 12, wherein the moisture content of the contents is 50% or more and 85% or less.

14. An outer container having barrier properties, The outer container comprises a sheet or inner bag, The aforementioned sheet comprises a polyolefin resin, a desiccant, and a hydrogen generating agent. The inner bag is formed from the sheet, The aforementioned sheet is A first layer comprising a polyolefin resin and a desiccant, The first layer is provided on one side and comprises a second layer containing a polyolefin resin and a hydrogen generating agent. The inner bag is a packaging container formed from the sheet, wherein the first layer of the sheet is positioned inside the second layer.

15. The packaging container according to claim 14, wherein the sheet is provided on the side of the second layer opposite to the first layer and further comprises a third layer containing a polyolefin resin.

16. The packaging container according to claim 15, wherein the desiccant is hydrotalcite.

17. A package in which contents are contained in the outer container of the packaging container according to any one of claims 14 to 16.

18. The packaging according to claim 17, wherein the moisture content of the contents is 50% or more and 85% or less.

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