Multilayer structure and method for manufacturing the same, packaging material using the same, vacuum adiabatic body, and protective sheet for electronic device

Abstract

The present invention provides a novel multilayer structure which is excellent in gas barrier properties and water vapor barrier properties, can maintain the gas barrier properties and water vapor barrier properties even after being bent, and does not cause appearance defects such as interlayer peeling after retort treatment, a packaging material and an article using the same. The present invention relates to a multilayer structure which has a substrate (X), a layer (Y), and a layer (Z), at least one set of the layer (Y) and the layer (Z) are adjacent and stacked, the layer (Y) contains a reaction product (D) of a metal oxide (A) and an inorganic phosphorus compound (BI), the metal oxide (A) contains aluminum atoms, the layer (Z) contains a metal compound (R) having metal atoms (M R ) and a hydroxyl group-containing resin (W), and the molar ratio M R / M MR of the number of moles (M Al ) of the metal atoms (M MR ) per unit area of the layer (Y) and the layer (Z) to the number of moles (M Al ) of aluminum atoms is 0.0005 or more and 0.05 or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a multilayer structure and a method for manufacturing the same, a packaging material using the same, a vacuum adiabatic body, and a protective sheet for electronic devices. BACKGROUND

[0002] Conventionally, a multilayer structure having a gas barrier layer formed of aluminum, aluminum oxide as a constituent component on a plastic film is well known, and it is used as a packaging material for protecting an article (e.g., food) that is easily deteriorated by oxygen, a constituent member of a protective sheet for electronic devices that requires gas barrier properties and water vapor barrier properties. The gas barrier layer is mostly formed on a plastic film by a dry method such as a physical vapor deposition method (PVD), a chemical vapor deposition method (CVD). However, for these evaporation films, the thin film of inorganic compounds for the gas barrier layer lacks flexibility, kneading property or bending weakness, and in addition, adhesion to the substrate is poor, so attention is required in handling, and in particular, in printing, lamination, bag making, and the like, post-processing of the packaging material, there is a problem that cracks are generated on the aforementioned thin film, and the gas barrier properties are significantly reduced.

[0003] For this problem, in Patent Literature 1, a method of applying a coating agent containing an aqueous solution or a water / alcohol mixed solution of a water-soluble polymer and at least one of (a) a metal alkoxide and / or a hydrolyzate thereof or (b) a stannic chloride as a main agent on a thin film of inorganic compounds, and applying a gas barrier outer coating layer excellent in flexibility, whereby the gas barrier properties are improved, and the protection effect of the evaporation layer is obtained, is described.

[0004] On the other hand, in recent years, a method of constructing a barrier layer by a process of applying a coating liquid has been used, and in Patent Literature 2, as an invention for improving the physical stress resistance of a barrier layer obtained by this method, a method of making a layer containing a polymer having a plurality of phosphorus atoms and a polymer having an ether bond and not having a glycosidic bond adjacent and laminated on a layer having aluminum atoms, whereby even after retort treatment, good interlayer adhesion is obtained, and the gas barrier properties when subjected to physical stress such as stretching are maintained at a high level, is described.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Laid-Open No. 07-234947

[0008] Patent Literature 2: International Publication No. 2016 / 103716 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] However, in the case where the above-described conventional multilayer structure is used as a packaging material, there are cases where the maintenance of gas barrier properties is insufficient when subjected to physical stress such as bending (hereinafter, simply referred to as "bending"), or cases where appearance defects such as interlayer peeling occur when subjected to severe conditions such as retort treatment (hereinafter, simply referred to as "after retort treatment").

[0011] An object of the present application is to provide a novel multilayer structure which is excellent in gas barrier properties and water vapor barrier properties, can maintain the gas barrier properties and water vapor barrier properties even after bending, and does not produce appearance defects such as interlayer peeling after retort treatment, a packaging material using the same, and a product. One of the other objects of the present application is to provide a protective sheet for electronic devices which uses a novel multilayer structure which is excellent in gas barrier properties and water vapor barrier properties, and can maintain the barrier properties even after a damp heat test. Note that the point that appearance defects such as interlayer peeling do not occur after retort treatment is sometimes simply referred to as "retort resistance".

[0012] Means for solving the problem

[0013] That is, the present application is achieved by the following means:

[0014] [1] A multilayer structure comprising a substrate (X), a layer (Y), and a layer (Z), at least one set of the layer (Y) and the layer (Z) being stacked adjacent to each other, the layer (Y) containing a reaction product (D) of a metal oxide (A) and an inorganic phosphorus compound (BI), the metal oxide (A) containing aluminum atoms, the layer (Z) containing a metal compound (R) having metal atoms (M R ) and a hydroxyl group-containing resin (W), the molar ratio M R / M MR of the number of moles (M Al ) of the metal atoms (M MR ) per unit area of the layer (Y) and the layer (Z) to the number of moles (M Al ) of aluminum atoms being 0.0005 or more and 0.05 or less.

[0015] [2] The multilayer structure according to [1], wherein the hydroxyl group-containing resin (W) has at least carbon atoms, the molar ratio M R / M MR of the number of moles (M MR ) of the metal atoms (M C ) per unit area of the layer (Z) to the number of moles (Mc) of carbon atoms being 0.0007 or more and 0.07 or less.

[0016] [3] The multilayer structure according to [1] or [2], wherein the metal atoms (M R ) include at least one selected from the group consisting of silicon, titanium, and zirconium.

[0017] [4] The multilayer structure according to any one of [1] to [3], wherein the aforementioned metal compound (R) contains at least one selected from a glycidyl group-containing silicon compound (G), an organic titanium compound (OT), and an organic zirconium compound (OZ);

[0018] [5] The multilayer structure according to [4], wherein the glycidyl group-containing silicon compound (G) is at least one compound represented by the following general formula (I),

[0019] Si (X1) p Z q R 1(4-p-q) (I)

[0020] In the above formula (I), X1 represents any one selected from F, Cl, Br, I, R20-, R3COO-, (R4CO)2CH-, and NO3, Z represents an organic group having a glycidyl group, R1, R2, R3, and R4 each independently represent any one group selected from an alkyl group, an aralkyl group, an aryl group, and an alkenyl group, p represents an integer of 1 to 3, q represents an integer of 1 to 3; 2 ≤ (p + q) ≤ 4; in the case where a plurality of X1 are present, these X1 can be the same as or different from each other; in the case where a plurality of Z are present, these Z can be the same as or different from each other; in the case where a plurality of R1 are present, these R1 can be the same as or different from each other;

[0021] [6] The multilayer structure according to [5], wherein the glycidyl group-containing silicon compound (G) is at least one selected from 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane;

[0022] [7] The multilayer structure according to any one of [4] to [6], wherein the organic titanium compound (OT) is at least one selected from an organic alkoxyl titanium, an organic acyl titanium, and an organic titanium chelate;

[0023] [8] The multilayer structure according to any one of [4] to [7], wherein the organic zirconium compound (OZ) is at least one selected from an organic alkoxyl zirconium, an organic acyl zirconium, and an organic zirconium chelate;

[0024] [9] The multilayer structure according to any one of [1] to [8], wherein the hydroxyl group-containing resin (W) is polyvinyl alcohol;

[0025]

[10] The multilayer structure according to any one of [1] to [9], wherein a mass ratio (W / R) of the hydroxyl group-containing resin (W) to the metal compound (R) in the layer (Z) is 2.0 or greater and 200 or less;

[0026]

[11] The multilayer structure according to any one of [1] to

[10] , having a laminated structure in which the substrate (X), the layer (Y), and the layer (Z) are laminated in this order;

[0027]

[12] The multilayer structure according to any one of [1] to

[11] , wherein an average thickness of the layer (Z) is 50 nm or greater;

[0028]

[13] The multilayer structure layer according to any one of [1] to

[12] , wherein a ratio (layer (Z) / layer (Y)) of the average thickness of the layer (Z) to the average thickness of the layer (Y) is 0.10 or greater;

[0029]

[14] A method for manufacturing the multilayer structure according to any one of [1] to

[13] , comprising:

[0030] (I) on the substrate (X), applying a coating liquid (S) containing a metal oxide (A) containing aluminum atoms, an inorganic phosphorus compound (BI), and a solvent, and forming a precursor layer of the layer (Y) by removing the solvent,

[0031] (II) on the aforementioned precursor layer of the layer (Y), applying a coating liquid (T) containing a resin (W), the aforementioned metal compound (R), and a solvent, and forming a precursor layer of the layer (Z) by removing the solvent, and

[0032] (III) heat-treating the aforementioned precursor layer of the layer (Y) and the aforementioned precursor layer of the layer (Z) to form the layer (Y) and the layer (Z);

[0033]

[15] A packaging material containing the multilayer structure according to any one of [1] to

[13] ;

[0034]

[16] The packaging material according to

[15] , which is a stand-up pouch, a vacuum packaging bag, a soft packaging bag, a laminated tube container, an infusion bag, a paper container, a tape, a lid material for a container, or an in-mold label container;

[0035]

[17] A vacuum heat insulator, wherein the packaging material according to

[16] is a vacuum packaging bag, the aforementioned vacuum packaging bag contains a content, the aforementioned content is a core material, and the inside of the aforementioned vacuum packaging bag is reduced in pressure;

[0036]

[18] A protective sheet for an electronic device containing the multilayer structure according to any one of [1] to

[13] .

[0037] Effects of the Invention

[0038] According to the present application, a novel multilayer structure having excellent gas barrier properties and water vapor barrier properties, maintaining the gas barrier properties and water vapor barrier properties even after bending, and not generating appearance defects such as interlayer peeling after retort treatment, a packaging material and an article using the same can be provided. Further, a protective sheet for electronic equipment using a novel multilayer structure having excellent gas barrier properties and water vapor barrier properties, and maintaining the barrier properties even after a damp heat test can be provided. DETAILED DESCRIPTION

[0039] In the present specification, "barrier properties" mainly refer to both oxygen barrier properties and water vapor barrier properties (moisture permeability), and "gas barrier properties" mainly refer to oxygen barrier properties. Further, the property of maintaining excellent barrier properties even after bending treatment is sometimes expressed as "bending resistance".

[0040] The multilayer structure of the present application has a substrate (X), a layer (Y), and a layer (Z), at least one set of the layer (Y) and the layer (Z) are adjacent and stacked, the layer (Y) contains a reaction product (D) of a metal oxide (A) and an inorganic phosphorus compound (BI), the layer (Z) contains a metal compound (R) and a resin (W), and the molar ratio M R / M MR of the number of moles (M Al ) of metal atoms (M MR ) per unit area of the layer (Y) and the layer (Z) to the number of moles (M Al ) of aluminum atoms is 0.0005 or more and 0.05 or less. For the multilayer structure of the present application, in particular, the layer (Z) contains a metal compound (R) and a resin (W), the molar ratio M R / M MR of the number of moles (M Al ) of metal atoms (M MR ) per unit area of the layer (Y) and the layer (Z) to the number of moles (M Al ) of aluminum atoms is 0.0005 or more and 0.05 or less, and thus a tendency to improve bending resistance and retort resistance is formed.

[0041] [Substrate (X)]

[0042] The material of the substrate (X) is not particularly limited, and a substrate formed of a variety of materials can be used. As the material of the substrate (X), resins such as thermoplastic resins, thermosetting resins, fiber assemblies such as cloth, paper, and the like, wood, glass, metals, metal oxides, and the like can be given. Among them, a thermoplastic resin and a fiber assembly are preferable, and a thermoplastic resin is more preferable. The form of the substrate (X) is not particularly limited, and can be a layer such as a film or a sheet. As the substrate (X), at least one selected from the group consisting of a thermoplastic resin film, a paper layer, and an inorganic vapor deposition layer (X') is preferable, and a thermoplastic resin film is more preferable, and a thermoplastic resin film is further preferable.

[0043] As the thermoplastic resin used in the substrate (X), polyolefin-based resins such as polyethylene and polypropylene; polyester-based resins such as polyethylene terephthalate (PET), polyethylene 2,6-naphthalate, polybutylene terephthalate, and copolymers thereof; polyamide-based resins such as nylon-6, nylon-66, and nylon-12; hydroxyl-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers; polystyrene; poly(meth)acrylate; polyacrylonitrile; polyvinyl acetate; polycarbonate; polyarylate; regenerated cellulose; polyimide; polyetherimide; polysulfone; polyethersulfone; polyether ether ketone; ionomer resins, and the like can be given. As the thermoplastic resin used in the substrate (X), at least one selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, nylon-6, and nylon-66 is preferable, and polyethylene terephthalate is more preferable.

[0044] When the aforementioned thermoplastic resin film is used as the aforementioned substrate (X), the substrate (X) can be a stretched film or a non-stretched film. The resulting multilayer structure is excellent in processability (printing, lamination, and the like), and thus a stretched film, particularly a biaxially stretched film is preferable. The biaxially stretched film can be a biaxially stretched film produced by any one of a simultaneous biaxial stretching method, a sequential biaxial stretching method, and a tubular stretching method.

[0045] As the paper used in the substrate (X), kraft paper, chemical pulp paper, imitation paper, glassine paper, parchment paper, synthetic paper, white board paper, manila paper, milk carton base paper, cup base paper, ivory paper, and the like can be given. By using paper in the substrate (X), a multilayer structure for a paper container can be obtained.

[0046] When the substrate (X) is a layer, the average thickness thereof is preferably 1 to 1000 μm, more preferably 5 to 500 μm, and further preferably 9 to 200 μm, from the viewpoint of achieving good mechanical strength and processability of the resulting multilayer structure.

[0047] The inorganic vapor deposition layer (X') is a layer that is generally barrier to oxygen and water vapor, and preferably has transparency. The inorganic vapor deposition layer (X') can be formed by vapor deposition of an inorganic substance. As the inorganic substance, a metal (e.g., aluminum), a metal oxide (e.g., silicon oxide, aluminum oxide), a metal nitride (e.g., silicon nitride), a metal oxynitride (e.g., silicon oxynitride), or a metal carbonitride (e.g., silicon carbonitride), or the like can be mentioned. Among them, from the viewpoint of excellent transparency, an inorganic vapor deposition layer (X') formed of aluminum oxide, silicon oxide, magnesium oxide, or silicon nitride is preferred.

[0048] The method of forming the inorganic vapor deposition layer (X') is not particularly limited, and physical vapor deposition methods such as vacuum deposition (e.g., resistance heating deposition, electron beam deposition, molecular beam epitaxy, ion plating, etc.), sputtering (dual magnetron sputtering, etc.); chemical vapor deposition methods such as thermal chemical vapor deposition (e.g., catalyst chemical vapor deposition), photochemical vapor deposition, plasma chemical vapor deposition (e.g., capacitively coupled plasma, inductively coupled plasma, surface wave plasma, electron cyclotron resonance plasma, etc.), atomic layer deposition, organometallic vapor deposition, etc. can be mentioned.

[0049] The average thickness of the inorganic vapor deposition layer (X') varies depending on the kind of the component constituting the inorganic vapor deposition layer, and is preferably 0.002 to 0.5 μm, more preferably 0.005 to 0.2 μm, and further preferably 0.01 to 0.1 μm. In this range, the average thickness at which the barrier property and the mechanical property of the multilayer structure become good can be selected. When the average thickness of the inorganic vapor deposition layer (X') is 0.002 μm or more, the barrier property of the inorganic vapor deposition layer (X') to oxygen and water vapor tends to become good. In addition, when the average thickness of the inorganic vapor deposition layer (X') is 0.5 μm or less, the inorganic vapor deposition layer (X') tends to maintain the barrier property after bending.

[0050] [Layer (Y)]

[0051] The layer (Y) contains a reaction product (D) of the metal oxide (A) and the inorganic phosphorus compound (BI). In the multilayer structure of the present application, since the layer (Y) functions as a barrier layer, the multilayer structure of the present application tends to have a good barrier property before bending by having the layer (Y).

[0052] [Metals Oxide (A) Containing Aluminum Atom]

[0053] The metal atoms (sometimes collectively referred to as "metal atoms (M)") constituting the metal oxide (A) are at least one metal atom selected from metal atoms belonging to Groups 2 to 14 of the periodic table, and at least include aluminum atoms. The metal atoms (M) are preferably aluminum atoms alone, but can include aluminum atoms and metal atoms other than aluminum atoms. Note that as the metal oxide (A), two or more kinds of metal oxides (A) can be mixed and used. As the metal atoms other than aluminum atoms, there are, for example, metals of Group 2 of the periodic table such as magnesium and calcium; metals of Group 12 of the periodic table such as zinc; metals of Group 13 of the periodic table; metals of Group 14 of the periodic table such as silicon; transition metals such as titanium and zirconium; and the like. Note that silicon is sometimes classified as a semimetal, but in this specification, metals include silicon. As the metal atoms (M) that can be used together with aluminum, at least one selected from titanium and zirconium is preferable from the viewpoint of workability and the gas barrier properties of the resulting multilayer structure.

[0054] The proportion of aluminum atoms in the metal atoms (M) is preferably 50 mol% or more, more preferably 70 mol% or more, and further preferably 90 mol% or more, and can be 95 mol% or more, or can consist of aluminum atoms alone. In examples of the metal oxide (A), there are metal oxides produced by a liquid phase synthesis method, a gas phase synthesis method, a solid pulverization method, or the like.

[0055] The metal oxide (A) can be a hydrolysis condensate of a compound (E) (hereinafter sometimes referred to simply as "compound (E)") containing metal atoms (M) to which a hydrolyzable functional group is bonded. As the functional group, there are, for example, a halogen atom, NO3, an alkoxy group having 1 to 9 carbon atoms optionally having a substituent, an aryloxy group having 6 to 9 carbon atoms optionally having a substituent, an acyloxy group having 2 to 9 carbon atoms optionally having a substituent, an alkenyloxy group having 3 to 9 carbon atoms optionally having a substituent, a β-diketonate group having 5 to 15 carbon atoms optionally having a substituent, or a diacylmethyl group having an acyl group having 1 to 9 carbon atoms optionally having a substituent, and the like. The hydrolysis condensate of the compound (E) can be regarded as a metal oxide (A) in essence. Therefore, in this specification, the hydrolysis condensate of the compound (E) is sometimes referred to as "metal oxide (A)". That is, in this specification, "metal oxide (A)" and "hydrolysis condensate of the compound (E)" can be used interchangeably, and in addition, "hydrolysis condensate of the compound (E)" can be used interchangeably with "metal oxide (A)".

[0056] [Compound (E) containing metal atoms (M) to which a hydrolyzable functional group is bonded]

[0057] From the viewpoint of easiness of control of the reaction with the inorganic phosphorus compound (BI), and excellent gas barrier properties of the resulting multilayer structure, it is preferred that the compound (E) contain a compound (Ea) containing an aluminum atom described later.

[0058] As the compound (Ea), there can be mentioned, for example, aluminum chloride, aluminum nitrate, aluminum acetate, tris (2, 4-pentanedionato) aluminum, trimethanol aluminum, triethanol aluminum, tri-n-propanol aluminum, triisopropanol aluminum, tri-n-butanol aluminum, tri-sec-butanol aluminum, tri-t-butanol aluminum, etc., of which triisopropanol aluminum and tri-sec-butanol aluminum are preferred. Two or more kinds of the compound (Ea) can be used in combination as the compound (E).

[0059] Further, the compound (E) can also contain a compound (Eb) containing a metal atom (M) other than aluminum, as the compound (Eb), there can be mentioned, for example, titanium compounds such as tetra (2, 4-pentanedionato) titanium, tetramethanol titanium, tetraethanol titanium, tetraisopropanol titanium, tetra-n-butanol titanium, tetra (2-ethylhexanol) titanium, etc.; zirconium compounds such as tetra (2, 4-pentanedionato) zirconium, tetra-n-propanol zirconium, tetra-n-butanol zirconium, etc. One kind of the compound can be used alone, or two or more kinds of the compound (Eb) can be used in combination.

[0060] The proportion of the compound (Ea) in the compound (E) is not particularly limited, and, for example, it is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more, and can be 100 mol%.

[0061] By hydrolysis of the compound (E), at least a part of the hydrolyzable characteristic group possessed by the compound (E) is converted into a hydroxyl group. Further, by condensation of the hydrolyzate, a compound in which the metal atom (M) is bonded via an oxygen atom (O) is formed. By repeating this condensation, a compound which can be regarded as substantially a metal oxide is formed. Note that on the surface of the metal oxide (A) thus formed, a hydroxyl group is generally present.

[0062] In the present specification, a compound having a proportion of [the number of moles of the oxygen atom (O) bonded only to the metal atom (M)] / [the number of moles of the metal atom (M)] of 0.8 or more is defined as a compound contained in the metal oxide (A). Here, the oxygen atom (O) bonded only to the metal atom (M) is the oxygen atom (O) in the structure of M-O-M, and is excluded from the oxygen atom (O) bonded to the metal atom (M) and the hydrogen atom (H) as in the structure of M-O-H. The aforementioned proportion of the metal oxide (A) is preferably 0.9 or more, more preferably 1.0 or more, and further preferably 1.1 or more. The upper limit of the proportion is not particularly limited, and is generally represented by n / 2 when the valence of the metal atom (M) is n.

[0063] In order to produce the aforementioned hydrolytic condensation, it is important that the compound (E) has a hydrolysable characteristic group. Without the bonding of these groups, the hydrolytic condensation reaction does not occur or becomes extremely slow, and thus it is difficult to produce the target metal oxide (A).

[0064] The hydrolytic condensate of the compound (E) can be produced from a specific raw material, for example, by a method employed in a publicly known sol-gel method. In the raw material, at least one selected from the group consisting of the compound (E), a partially hydrolyzed product of the compound (E), a completely hydrolyzed product of the compound (E), a compound produced by partially hydrolytic condensation of the compound (E), and a compound produced by partially condensation of a completely hydrolyzed product of the compound (E) can be used.

[0065] It should be noted that the metal oxide (A) to be mixed with the inorganic phosphorus compound (BI) containing substance (inorganic phosphorus compound (BI) or composition containing the inorganic phosphorus compound (BI)) described later is preferably substantially free of phosphorus atoms.

[0066] [Inorganic phosphorus compound (BI)]

[0067] The inorganic phosphorus compound (BI) contains a site capable of reacting with the metal oxide (A), and typically contains a plurality of the sites, suitably 2 to 20. The sites include a site capable of condensation reaction with a functional group (e.g., hydroxyl group) present on the surface of the metal oxide (A), and examples include a halogen atom directly bonded to a phosphorus atom, an oxygen atom directly bonded to a phosphorus atom, and the like. The functional group (e.g., hydroxyl group) present on the surface of the metal oxide (A) is generally bonded to a metal atom (M) constituting the metal oxide (A).

[0068] As the inorganic phosphorus compound (BI), examples include phosphoric acid, diphosphoric acid, triphosphoric acid, polyphosphoric acid produced by condensation of 4 or more molecules of phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, hypophosphorous acid, phosphorous acid of valence 3 or more, and salts (e.g., sodium phosphate) and derivatives (e.g., halide (e.g., phosphorus oxychloride), anhydride (e.g., diphosphorus pentoxide)) thereof, and the like. These inorganic phosphorus compounds (BI) can be used singly or in combination of two or more. Among them, from the viewpoint of stability of the coating liquid (S) described later and improvement of gas barrier properties of the obtained multilayer structure, it is preferable to use phosphoric acid singly or in combination with an inorganic phosphorus compound (BI) other than phosphoric acid. In the case of using phosphoric acid in combination with an inorganic phosphorus compound (BI) other than phosphoric acid, it is preferable that 50 mol% or more of the inorganic phosphorus compound (BI) be phosphoric acid.

[0069] [Reaction product (D)]

[0070] The reaction product (D) can be obtained by reacting the metal oxide (A) with the inorganic phosphorus compound (BI). A compound formed by further reacting the metal oxide (A) with the inorganic phosphorus compound (BI) and other compounds is also included in the reaction product (D).

[0071] In the infrared absorption spectrum of the layer (Y), the maximum absorption wavenumber in the region of 800 to 1400 cm -1 -1 is preferably in the range of 1080 to 1130 cm -1 -1. For example, in the process of forming the reaction product (D) by reacting the metal oxide (A) with the inorganic phosphorus compound (BI), a metal atom (M) derived from the metal oxide (A) and a phosphorus atom (P) derived from the inorganic phosphorus compound (BI) form a bond represented by M-O-P via an oxygen atom (O). As a result thereof, a characteristic absorption band derived from the bond is generated in the infrared absorption spectrum of the reaction product (D). In the case where the characteristic absorption band based on the bond of M-O-P is visible in the region of 1080 to 1130 cm -1 -1, the obtained multilayer structure exhibits excellent gas barrier properties. In particular, in the case where the characteristic absorption band is the strongest absorption in the region of 800 to 1400 cm -1 -1 in which absorption derived from the bond of various atoms and oxygen atoms is generally visible, the obtained multilayer structure exhibits further excellent gas barrier properties.

[0072] In this regard, in the case where a metal compound such as the compound (E) or a metal salt is mixed with the inorganic phosphorus compound (BI) in advance and then subjected to hydrolysis and condensation, a complex in which a metal atom derived from the metal compound and a phosphorus atom derived from the inorganic phosphorus compound (BI) are substantially uniformly mixed and reacted can be obtained. In this case, in the infrared absorption spectrum, the maximum absorption wavenumber in the region of 800 to 1400 cm -1 -1 deviates from the range of 1080 to 1130 cm -1 -1.

[0073] In the infrared absorption spectrum of the layer (Y), the half width of the maximum absorption band in the region of 800 to 1400 cm -1 -1 is preferably 200 cm -1 -1 or more, more preferably 150 cm -1 -1 or more, further preferably 100 cm -1 -1 or more, and particularly preferably 50 cm -1 -1 or less.

[0074] The infrared absorption spectrum of the layer (Y) can be measured using a Fourier transform infrared spectrophotometer (Spectrum One manufactured by PerkinElmer) in the range of 800 to 1400 cm -1The measurement is performed as a measurement region using an attenuated total reflection method. However, in cases where measurement using the aforementioned method is not possible, measurement can also be performed using a reflection method such as a reflection absorption method, an external reflection method, an attenuated total reflection method, a transmission method such as a layer (Y) scraping method from a multilayer structure, a paraffin paste method, a tablet method, and the like, but is not limited to these methods.

[0075] Further, the layer (Y) can partially contain a metal oxide (A) that does not participate in the reaction and / or an inorganic phosphorus compound (BI).

[0076] In the layer (Y), the molar ratio of the metal atoms constituting the metal oxide (A) to the phosphorus atoms derived from the inorganic phosphorus compound (BI) is preferably in the range of [metal atoms constituting the metal oxide (A)] : [phosphorus atoms derived from the inorganic phosphorus compound (BI)] = 1.0 : 1.0 to 3.6 : 1.0, and more preferably in the range of 1.1 : 1.0 to 3.0 : 1.0. In this range, excellent gas barrier properties can be obtained. This molar ratio in the layer (Y) can be adjusted by the mixing ratio of the metal oxide (A) and the inorganic phosphorus compound (BI) in the coating liquid (S) used to form the layer (Y). The molar ratio in the layer (Y) is usually the same as the ratio in the coating liquid (S).

[0077] The average thickness of the layer (Y) (in the case where the multilayer structure has two or more layers (Y), the total of the average thickness of each layer (Y)) is preferably 0.05 to 4.0 μm, and more preferably 0.1 to 2.0 μm. By thinning the layer (Y), the dimensional change of the multilayer structure at the time of printing, lamination, and the like can be suppressed to a low level. Further, in order to increase the flexibility of the multilayer structure, the mechanical properties can also be made close to the mechanical properties of the substrate itself. In the case where the multilayer structure of the present application has two or more layers (Y), the average thickness of each layer (Y) is preferably 0.05 μm or more from the viewpoint of gas barrier properties. The average thickness of the layer (Y) can be controlled by the concentration of the coating liquid (S) described later used in the formation of the layer (Y) or the coating method thereof. The average thickness of the layer (Y) can be measured by observing the cross section of the multilayer structure with a scanning electron microscope or a transmission electron microscope.

[0078] The layer (Y) can also contain a polymer (F) having at least one functional group selected from the group consisting of a carbonyl group, a hydroxyl group, a carboxyl group, a carboxylic anhydride group, and a salt of a carboxyl group, in addition to the aforementioned components. Note that the polymer (F) partially overlaps with the resin (W), and the hydroxyl group-containing resin contained in the layer (Y) is regarded as the polymer (F), and the hydroxyl group-containing resin contained in the layer (Z) is regarded as the resin (W).

[0079] [Polymer (F)]

[0080] The polymer (F) has at least one functional group selected from the group consisting of a carbonyl group, a hydroxyl group, a carboxyl group, a carboxylic anhydride group, and a salt of a carboxyl group. The polymer (F) is preferably a polymer having at least one functional group selected from the group consisting of a hydroxyl group and a carboxyl group.

[0081] As the polymer (F), polyethylene glycol; polyvinyl alcohol, modified polyvinyl alcohol containing 1 to 50 mol% of α-olefin units having 4 or less carbon atoms, polyvinyl alcohol-based polymers such as polyvinyl acetal (polyvinyl butyral, etc.); polysaccharides such as cellulose, starch, etc.; (meth)acrylic acid-based polymers such as poly(hydroxyethyl) (meth)acrylate, poly(meth)acrylic acid, ethylene-methacrylic acid copolymer, etc.; maleic acid-based polymers such as hydrolyzates of ethylene-maleic anhydride copolymer, hydrolyzates of styrene-maleic anhydride copolymer, hydrolyzates of isobutylene-maleic anhydride alternating copolymer, etc. can be exemplified. Among them, polyethylene glycol and polyvinyl alcohol-based polymers are preferable. The suitable mode of the polyvinyl alcohol-based polymer used as the polymer (F) is the same as the resin (W) contained in the layer (Z).

[0082] The polymer (F) can be a homopolymer of a monomer having a polymerizable group, can be a copolymer of two or more kinds of monomers, or can be a copolymer of a monomer having at least one functional group selected from the group consisting of a carbonyl group, a hydroxyl group, a carboxyl group, a carboxylic anhydride group, and a salt of a carboxyl group and a monomer not having the group. Note that two or more kinds of polymer (F) can be mixed and used as the polymer (F).

[0083] The molecular weight of the polymer (F) is not particularly limited, and in order to obtain a multilayer structure having more excellent gas barrier properties and mechanical strength, the weight average molecular weight of the polymer (F) is preferably 5,000 or more, more preferably 8,000 or more, and further preferably 10,000 or more. The upper limit of the weight average molecular weight of the polymer (F) is not particularly limited, and is, for example, 1,500,000 or less.

[0084] From the viewpoint of maintaining the appearance of the multilayer structure well, the content of the polymer (F) in the layer (Y) is preferably less than 50% by mass, more preferably 20% by mass or less, and further preferably 10% by mass or less, based on the mass of the layer (Y), and can be 0% by mass. The polymer (F) can or can not react with the components in the layer (Y).

[0085] The layer (Y) can further contain other components. As the other components that can be contained in the layer (Y), there can be mentioned, for example, inorganic acid metal salts such as carbonates, hydrochlorides, nitrates, bicarbonates, sulfates, bisulfates, borates and the like; organic acid metal salts such as oxalates, acetates, tartrates, stearates and the like; metal complexes such as cyclopentadienyl metal complexes (e.g., titanium complexes), cyanide metal complexes (e.g., Prussian blue) and the like; layered clay compounds; crosslinking agents; high molecular compounds other than the polymer (F); plasticizers; antioxidants; ultraviolet absorbers; flame retardants and the like. The content of the aforementioned other components in the layer (Y) in the multilayer structure is preferably 50% by mass or less, more preferably 20% by mass or less, further preferably 10% by mass or less, particularly preferably 5% by mass or less, and can be 0% by mass (does not contain other components).

[0086] In the case where the layer (Y) contains the polymer (F), the content of the reaction product (D) and the polymer (F) in the layer (Y) is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, particularly preferably 95% by mass or more, and can consist substantially of the reaction product (D) and the polymer (F) alone. Note that in the case where a part of the unreacted metal oxide (A) and the inorganic phosphorus compound (BI) are contained in the layer (Y), the content of the metal oxide (A), the inorganic phosphorus compound (BI), the reaction product (D) and the polymer (F) in the layer (Y) is preferably within the above-mentioned range.

[0087] [Layer (Z)]

[0088] The layer (Z) contains the metal compound (R) and the resin (W), and the molar ratio M R / M MR of the number of moles (M Al ) of the metal atom (M MR ) per unit area of the layer (Y) and the layer (Z) with respect to the number of moles (M Al ) of the aluminum atom is 0.0005 or more and 0.05 or less. By providing the multilayer structure of the present application with the layer (Z), there is a tendency that the bending resistance and the boiling resistance become good. The reason why the bending resistance and the boiling resistance become good is not clear, but it is considered that the reaction (crosslinking) of the metal compound (R) with the resin (W) is an important reason. The molar ratio M MR / M Al is preferably 0.0006 or more and 0.045 or less, more preferably 0.0007 or more and 0.042 or less, further preferably 0.0009 or more and 0.040 or less. The method for calculating the molar ratio M MR / M Al is described in the Examples described later.

[0089] [metal compound (R)]

[0090] The metal compound (R) is a compound having a metal atom (M R ) and by including the metal compound (R) in the layer (Z), a tendency to achieve both the resistance to bending and the resistance to retort can be formed.

[0091] As the metal atom (M R ), any metal atom can be selected, and one kind alone can be used or two or more kinds can be used in combination. As the metal atom (M R ), from the viewpoint of further improving the reactivity with the resin (W), it is preferable to include at least one selected from silicon, titanium, and zirconium, and more preferable to include at least one selected from silicon and titanium.

[0092] As the metal atom (M R ) is silicon, as the metal compound (R), there can be mentioned silicon compounds having low reactivity with the resin (W) such as alkoxysilane, halosilane, vinylsilane, alkylsilane, and silicon compounds having high reactivity with the resin (W) having an organic group such as glycidyl group, amino group, acryloyl group, isocyanate group, and mercapto group. Among them, from the viewpoint of excellent resistance to bending and resistance to retort, it is preferable to be a silicon compound having high reactivity with the resin (W), and more preferable to be a silicon compound (G) having a glycidyl group (hereinafter sometimes abbreviated as "silicon compound (G)").

[0093] The metal compound (R) is preferably at least one selected from a silicon compound (G), an organic titanium compound (OT), and an organic zirconium compound (OZ) from the viewpoint of good reactivity with the resin (W), and more preferably at least one selected from a silicon compound (G) and an organic titanium compound (OT). Further, the metal compound (R) is preferably at least one selected from a silicon compound (G), an organic titanium compound (OT), and an organic zirconium compound (OZ) from the viewpoint of good reactivity with the resin (W), and more preferably at least one selected from a silicon compound (G) and an organic titanium compound (OT).

[0094] The silicon compound (G) is preferably at least one silicon compound represented by the following general formula (I).

[0095] Si (X1) p Z q R 1(4-p-q) (I)

[0096] [In the above formula (I), X1 represents any one selected from the group consisting of F, Cl, Br, I, R2O", R3COO", (R4CO)2CH", and NO3, Z represents an organic group having a glycidyl group, R1, R2, R3, and R4 each independently represents any one group selected from the group consisting of an alkyl group, an aralkyl group, an aryl group, and an alkenyl group, p represents an integer of 1 to 3, and q represents an integer of 1 to 3. 2 ≤ (p + q) ≤ 4. In the case where a plurality of X1 are present, these X1 can be the same as or different from each other. In the case where a plurality of Z are present, these Z can be the same as or different from each other. In the case where a plurality of R1 are present, these R1 can be the same as or different from each other.]

[0097] R1, R2, R3, and R4 are, for example, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms.

[0098] In formula (I), the glycidyl group in the "organic group having a glycidyl group" represented by Z contributes to the formation (reaction) of a covalent bond with the resin (W). Z in formula (I) can have only one glycidyl group, or can have a plurality of glycidyl groups.

[0099] In a preferred example, X1 is a halogen atom or an alkoxy group (R2O") having 1 to 4 carbon atoms, Z is an alkyl group having 1 to 4 carbon atoms having a glycidyl group, R1 is an alkyl group having 1 to 4 carbon atoms, p is 2 or 3, and q is 1 or 2, 3 ≤ (p + q) ≤ 4. 1 In a particularly preferred example, X1 is a halogen atom or an alkoxy group (R2O") having 1 to 4 carbon atoms, Z is an alkyl group having 1 to 4 carbon atoms having a glycidyl group, p is 3, and q is 1.

[0100] The metal atom (M RIn the case of silicon, as the metal compound (R), there can be mentioned, for example, tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, octyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, chlorotrimethoxysilane, chlorotriethoxysilane, dichlorodimethoxysilane, dichlorodiethoxysilane, trichloromethoxysilane, trichloroethoxysilane, vinyltrichlorosilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltriisopropoxysilane, 3-glycidoxypropyltributoxysilane, 3-glycidoxypropyltrichlorosilane, 3-glycidoxypropylmethyl-dimethoxysilane, 3-glycidoxypropylmethyl-diethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2(aminoethyl)-3-aminopropyltrimethoxysilane, N-2(aminoethyl)-3-aminopropylmethyl-dimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and the like. Among them, preferred are 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyl-dimethoxysilane, 3-glycidoxypropylmethyl-diethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, which belong to silicon compounds (G), more preferred are 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane.

[0101] As the organic titanium compound (OT), at least one selected from the group consisting of organic alkoxyl titanium, organic acyl titanium and organic titanium chelate is preferred. As the organic titanium compound (OT), there can be mentioned, for example, titanium lactate, partial or complete neutralization of titanium lactate (e.g., ammonium titanium lactate salts such as titanium lactate monoammonium salt, titanium lactate diammonium salt, and the like; sodium titanium lactate salts such as titanium lactate monosodium salt, titanium lactate disodium salt, and the like; potassium titanium lactate salts such as titanium lactate monopotassium salt, titanium lactate dipotassium salt, and the like), bis(triethanolamine) titanium diisopropylate, bis(triethanolamine) titanium di-n-butylate, bis(acetylacetonato) titanium diisopropylate, titanium tetraacetylacetonate, bis(acetylacetonato) polytitanium, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetrastearate, and the like. Among them, preferred are water-soluble substances having a ligand of chelate type, specifically, titanium lactate, partial or complete neutralization of titanium lactate, bis(triethanolamine) titanium diisopropylate, bis(triethanolamine) titanium di-n-butylate, more preferred is titanium lactate or partial or complete neutralization thereof. As the partial or complete neutralization of titanium lactate, ammonium titanium lactate salt is preferred.

[0102] As the organic zirconium compound (OZ), at least one selected from the group consisting of an organic alkoxyl zirconium compound, an organic acyl zirconium compound, and an organic zirconium chelate compound is preferable. As the organic zirconium compound (OZ), for example, dibutoxy bis (ethyl acetate) zirconium octanoate, zirconium stearate, zirconium oxychloride, zirconium lactate ammonium salt, and the like can be exemplified. Among them, a water-soluble substance is preferable, and specifically, zirconium oxychloride, zirconium lactate ammonium salt is preferable.

[0103] In the case where the metal compound (R) contains a silicon compound having an alkoxy group, from the viewpoint of more excellent resistance to bending and resistance to retort, it is preferable to include a process in which a solvent is added to the metal compound (R), and then an acid catalyst and water are added and hydrolysis condensation is performed by a publicly known sol-gel method.

[0104] The metal compound (R) can be one alone, or two or more can be used in combination.

[0105] [Resin (W)]

[0106] The resin (W) is a resin containing a hydroxyl group, and when the resin (W) is used, there is a tendency that resistance to bending becomes good. The resin (W) is preferably a hydrophilic resin, and more preferably a water-soluble or water-dispersible resin. From the viewpoint of high hydrophilicity, the resin (W) preferably has a monomer unit having a hydroxyl group, and the content of the monomer unit having a hydroxyl group with respect to the total monomer units constituting the resin (W) is preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 65 mol% or more, and particularly preferably 90 mol% or more. In addition, in the resin (W), the content of the monomer unit having a hydroxyl group with respect to the total monomer units constituting the resin (W) can be 100 mass% or less, or 99.9 mass% or less. When the content of the monomer unit having a hydroxyl group in the resin (W) is within the above range, there is a tendency that resistance to bending becomes good.

[0107] As the resin (W), a hydroxyl group-containing epoxy resin, a hydroxyl group-containing polyester resin, a hydroxyl group-containing (meth) acrylic resin, a hydroxyl group-containing polyurethane resin, a vinyl alcohol-based resin, a polysaccharide, and the like can be exemplified, and among them, a vinyl alcohol-based resin or a polysaccharide is preferably included from the viewpoint of more excellent resistance to retort, and a vinyl alcohol-based resin is more preferably included, and further a vinyl alcohol-based resin is preferable.

[0108] Examples of vinyl alcohol-based resins include polyvinyl alcohol (hereinafter sometimes abbreviated as "PVA") resin and ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as "EVOH") resin. From the viewpoint of flexural strength, PVA resin is preferred. Examples of PVA resins include PVA resins obtained by homopolymerization and saponification of vinyl esters, and modified PVA resins with other modifying groups. Modified PVA resins can be copolymerized or post-modified. Similarly, examples of EVOH resins include EVOH resins obtained by copolymerization and saponification of vinyl esters and ethylene, and modified EVOH resins with other modifying groups. Modified EVOH resins can be copolymerized or post-modified. These vinyl alcohol-based resins can be used alone or in combination. It should be noted that in this specification, resins with an ethylene unit content of 20 mol% or more are defined as EVOH resins, and resins with an ethylene unit content of less than 20 mol% are defined as PVA resins.

[0109] The degree of saponification of the PVA resin is preferably 40 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more. Furthermore, the degree of saponification of the PVA resin can be 99.9 mol% or less. When the degree of saponification is 40 mol% or more, there is a tendency for better adhesion to the layer (Y). Furthermore, when the degree of saponification is 99.9 mol% or less, the preparation of the coating liquid (T) described later becomes easier. The degree of saponification of the PVA resin is determined by... 1 The result is calculated by measuring the peak areas of hydrogen atoms in the vinyl ester structure and the peak areas of hydrogen atoms in the vinyl alcohol structure using H-NMR.

[0110] The degree of saponification of the EVOH resin is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. Furthermore, the degree of saponification of the EVOH resin can be 99.9 mol% or less. By adjusting the degree of saponification to the above range, there is a tendency for improved flexural strength. Additionally, the ethylene unit content of the EVOH resin can be 20 mol% or more and 60 mol% or less, preferably 40 mol% or less, and more preferably 30 mol% or less. By having an ethylene unit content of 60 mol% or less in the EVOH resin, there is a tendency for improved flexural strength. The degree of saponification of the EVOH resin is determined by... 1 The result is calculated by measuring the peak areas of hydrogen atoms in the vinyl ester structure and the peak areas of hydrogen atoms in the vinyl alcohol structure using H-NMR.

[0111] When a vinyl alcohol resin has a modifying group, examples of such modifying groups include silanol, thiol, aldehyde, carboxyl, sulfonic acid, nitro, and amino groups, with silanol being the preferred option.

[0112] As the other monomer to be copolymerized with the vinyl ester in the case where the vinyl alcohol-based resin is copolymerized, there are, for example, olefins such as ethylene, propylene, isobutylene, a- octene, a-dodecene, a-octadecene, and the like; a-olefins containing a hydroxyl group such as 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, and the like, and derivatives thereof such as acylates thereof; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, undecylenic acid, and the like, salts, monoesters, or dialkyl esters thereof; nitriles such as acrylonitrile, methacrylonitrile, and the like; amides such as diacetone acrylamide, acrylamide, methacrylamide, and the like; olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, methylallyl sulfonic acid, and the like, or salts thereof; alkyl vinyl ethers, dimethylallyl vinyl ketone, N-vinylpyrrolidone, chloroethylene, vinylidene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerol monoallyl ether, 3,4-diacetyloxy-1-butene, and the like vinyl compounds; substituted vinyl acetates such as isopropenyl acetate, 1-methoxyvinyl acetate, and the like; vinylidene chloride; 1,4-diacetyloxy-2-butene; and vinylene carbonate. In the case where the vinyl alcohol-based resin contains the above other monomer, the content thereof can be 10 mol% or less, 5 mol% or less, or 3 mol% or less.

[0113] As the polysaccharide, a substance having a molecular weight of 2000 or more is preferable, and there are, for example, starch, cellulose, dextrin, and the like, among which, from the viewpoint that the coating liquid (T) to be described later can be easily prepared, dextrin is preferable. As the starch, known starches can be used, and there are, for example, amylose, amylopectin, and the like. As the cellulose, known celluloses can be used, and since it is generally not soluble in water, it is preferable to be dispersed in the coating liquid (T) to be described later.

[0114] The viscosity of a 4 mass% aqueous solution of the resin (W) at 20°C, measured in accordance with JIS K 6726 (1994), is preferably 1 mPa s or more and 100 mPa s or less, more preferably 3 mPa s or more and 90 mPa s or less, and particularly preferably 5 mPa s or more and 80 mPa s or less. When within the foregoing range, it is easy to adjust the layer (Z) to a uniform average thickness, and a tendency to stably reproduce the bending resistance of the obtained multilayer structure can be formed. The viscosity can be measured using a commercially available Brookfield-type rotational viscometer.

[0115] The molar ratio M R / M MR of the number of moles (M MR ) of the metal atom (M CPreferably, the molar ratio M is 0.0007 or more, more preferably 0.002 or more, and further preferably 0.003 or more. The molar ratio M MR / M C When the molar ratio M is 0.0007 or more, there is a tendency that the resistance to boiling becomes good. In addition, the molar ratio M MR / M C Preferably, the molar ratio M is 0.07 or less, more preferably 0.03 or less, and further preferably 0.015 or less. The molar ratio M MR / M C When the molar ratio M is 0.07 or less, there is a tendency that the resistance to bending becomes good. The molar ratio M MR / M C The method for calculating the molar ratio M is described later in the Examples.

[0116] The mass ratio (W / R) of the hydroxyl group-containing resin (W) to the metal compound (R) in the layer (Z) is preferably 2.0 or more, more preferably 4.0 or more, and further preferably 9.0 or more. When the mass ratio (W / R) is 2.0 or more, there is a tendency that the resistance to bending becomes good. In addition, the mass ratio (W / R) is preferably 200 or less, more preferably 90 or less, and further preferably 60 or less. When the mass ratio (W / R) is 200 or less, there is a tendency that the resistance to boiling becomes good.

[0117] The layer (Z) can contain other components within a range not hindering the effects of the present application. As the other components that can be contained in the layer (Z), there can be mentioned, for example, inorganic acid metal salts such as carbonates, hydrochlorides, nitrates, bicarbonates, sulfates, bisulfates, borates, and the like; organic acid metal salts such as oxalates, acetates, tartrates, stearates, and the like; metal complexes such as cyclopentadienyl metal complexes (e.g., titanium complexes), cyanide metal complexes (e.g., Prussian blue), and the like; layered clay compounds, crosslinking agents, high molecular compounds other than the resin (W), plasticizers, antioxidants, ultraviolet absorbers, flame retardants, and the like. The content of the aforementioned other components in the layer (Z) is preferably less than 10% by mass, more preferably less than 5% by mass, further preferably less than 3% by mass, particularly preferably less than 1% by mass, and can be 0% by mass (no other components are contained). That is, the proportion of the metal compound (R) and the resin (W) in the layer (Z) is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 99% by mass or more, and can consist substantially of or consist of only the metal compound (R) and the resin (W). In the case where the layer (Z) contains at least one selected from the group consisting of the silicon compound (G), the organic titanium compound (OT), and the organic zirconium compound (OZ), the proportion of at least one selected from the group consisting of the silicon compound (G), the organic titanium compound (OT), and the organic zirconium compound (OZ) in the layer (Z) is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, further preferably 1.5% by mass or more. When the mass ratio is 0.5% by mass or more, there is a tendency that the resistance to cooking becomes good. Furthermore, the proportion of at least one selected from the group consisting of the silicon compound (G), the organic titanium compound (OT), and the organic zirconium compound (OZ) in the layer (Z) is preferably 30% by mass or less, more preferably 20% by mass or less, further preferably 17% by mass or less. When the mass ratio is 30% by mass or less, there is a tendency that the resistance to bending becomes good. It should be noted that the layer (Z) can contain phosphorus atoms, but the proportion thereof is preferably 5% by mole or less, more preferably 3% by mole or less, further preferably 1% by mole or less, and particularly preferably substantially no phosphorus atoms are contained. Furthermore, the layer (Z) can contain the reaction product (D), but the proportion thereof is preferably 10% by mole or less, more preferably 5% by mole or less, further preferably 1% by mole or less, and particularly preferably substantially no reaction product (D) is contained.

[0118] As the method for forming the layer (Z), there can be used, for example, well-known printing methods such as offset printing, gravure printing, screen printing, and the like; well-known coating methods such as roll coating, knife coating, gravure coating, and the like. The drying conditions can be the conditions generally used.

[0119] The average thickness of layer (Z) is preferably 50 nm or more, more preferably 60 nm or more, and even more preferably 100 nm or more. When the average thickness of layer (Z) is 50 nm or more, it tends to improve the bending resistance. The average thickness of layer (Z) can be measured using the method described in the embodiments described later. The average thickness of layer (Z) can be 3000 nm or less, 1000 nm or less, 500 nm or less, or 300 nm or less. When the average thickness of layer (Z) exceeds 3000 nm, the improvement effect on bending resistance provided by layer (Z) tends to become saturated. It should be noted that the metal atoms (M) per unit area of ​​layer (Y) and layer (Z) described later... R The number of moles (M) MR ) relative to the number of moles of aluminum atoms (M) Al The molar ratio M MR / M Al The average thickness of the layer (Z) can be adjusted.

[0120] The ratio of the average thickness of layer (Z) to the average thickness of layer (Y) (layer (Z) / layer (Y)) is preferably 0.10 or more, more preferably 0.15 or more, and even more preferably 0.20 or more. When the ratio of the average thickness (layer (Z) / layer (Y)) is 0.10 or more, there is a tendency for good bending resistance. The ratio of the average thickness (layer (Z) / layer (Y)) can be 1.5 or less.

[0121] [Other Layers (J)]

[0122] To impart a variety of properties (e.g., heat-sealing properties, barrier properties, mechanical properties), the multilayer structure of the present invention may include other layers (J). Such a multilayer structure of the present invention can be manufactured, for example, by laminating layers (Y) on a substrate (X) (as needed via an adhesive layer (I) described later), and after laminating layers (Y) (Z), further bonding or forming the other layers (J) directly or via the adhesive layer (I) described later. Examples of other layers (J) include, for example, ink layers; polyolefin layers, thermoplastic resin layers such as ethylene-vinyl alcohol copolymer resin layers, etc., but are not limited to these.

[0123] In the case where the multilayer structure of the present application includes an ink layer, as the ink layer, a coating film obtained by drying a liquid obtained by dispersing a polyurethane resin including a pigment (e.g., titanium dioxide) in a solvent can be mentioned, and a coating film obtained by drying an ink in which a polyurethane resin not including a pigment, another resin, or the like is used as a main agent, a resist for circuit wiring formation can also be mentioned. As the application method of the ink layer, in addition to the gravure printing method, various application methods such as a wire bar, a spin coater, a die coater, and the like can be mentioned. The thickness of the ink layer is preferably 0.5 to 10.0 μm, and more preferably 1.0 to 4.0 μm.

[0124] By making the surface layer of the multilayer structure of the present application a polyolefin layer, heat sealability can be imparted to the multilayer structure, or the mechanical properties of the multilayer structure can be improved. From the viewpoint of improving heat sealability, mechanical properties, and the like, the polyolefin is preferably polypropylene or polyethylene. In addition, in order to improve the mechanical properties of the multilayer structure, it is preferable to laminate at least one film selected from a film formed of a polyester, a film formed of a polyamide, and a film formed of a hydroxyl group-containing polymer. From the viewpoint of improving the mechanical properties, as the polyester, polyethylene terephthalate is preferable; as the polyamide, nylon-6 is preferable; and as the hydroxyl group-containing polymer, an ethylene-vinyl alcohol copolymer is preferable.

[0125] The other layer (J) can be a layer formed by extrusion coating lamination. The extrusion coating lamination method that can be used in the present application is not particularly limited, and a publicly known method can be used. In a typical extrusion coating lamination method, a molten thermoplastic resin is fed into a T die, and the thermoplastic resin taken out from the flat slit of the T die is cooled, whereby a laminated film is produced.

[0126] As the extrusion coating lamination method other than the aforementioned single type lamination method, a sandwich lamination method, a series lamination method, and the like can be mentioned. The sandwich lamination method is a method in which a molten thermoplastic resin is extruded onto one side of a base material, a second base material is supplied from another unwinder (uncoiler) and is attached, and a laminate is produced. The series lamination method is a method in which two single type lamination machines are connected and a laminate of a 5-layer structure is produced at one time.

[0127] [Adhesive layer (I)]

[0128] In the multilayer structure of the present application, an adhesive layer (I) can be used to improve the adhesion between the substrate (X) and the layer (Y), or to improve the adhesion with other members (e.g., other layer (J), etc.). The adhesive layer (I) can be composed of an adhesive resin. As an adhesive resin for improving the adhesion with the aforementioned other members, a two-component reaction type polyurethane-based adhesive in which a polyisocyanate component and a polyol component are mixed and reacted is preferred. Further, by adding a small amount of an additive such as a known silane coupling agent to an anchor coating agent or an adhesive, the adhesion can sometimes be further improved. As the silane coupling agent, a silane coupling agent having a reactive group such as an isocyanate group, an epoxy group, an amino group, a urea group, a mercapto group, etc. can be exemplified, but is not limited thereto. By the adhesion with the other members, when the multilayer structure of the present application is subjected to processing such as printing or lamination, the deterioration of the gas barrier property or the appearance can be more effectively suppressed, and further, the drop strength of the packaging material using the multilayer structure of the present application can sometimes be improved.

[0129] Further, as an adhesive resin for improving the adhesion between the substrate (X) and the layer (Y), in addition to the aforementioned adhesive resin, a polyester-based resin, a polyurethane-based resin, a vinyl alcohol-based resin, etc. are suitably used, and from the viewpoint of improving the adhesion between the substrate (X) and the layer (Y), a vinyl alcohol-based resin is more preferably used alone, or a vinyl alcohol-based resin and a polyester-based resin are used together. The vinyl alcohol-based resin is preferably a PVA resin, and as the PVA resin, a form suitable for use as the resin (W) is preferred.

[0130] When a vinyl alcohol-based resin and a polyester-based resin are used together, the mass ratio (vinyl alcohol-based resin / polyester-based resin) is preferably 1 / 99 or more and 50 / 50 or less from the viewpoint of maintaining good adhesion while exhibiting higher peel strength. The polyester-based resin is preferably a polyester-based resin having a carboxyl group from the viewpoint of the affinity with the vinyl alcohol-based resin. Further, when used as an adhesive, the polyester-based resin is preferably in an aqueous dispersion. By making the polyester-based resin an aqueous dispersion, the affinity with the polyvinyl alcohol-based resin becomes better. The thickness of the adhesive layer (I) is preferably 0.001 to 10.0 μm, and more preferably 0.01 to 5.0 μm.

[0131] [Configuration of Multilayer Structure]

[0132] For the multilayer structure of the present application, at least one set of layer (Y) and layer (Z) are adjacent and laminated. Here, adjacent and laminated means that layer (Y) and layer (Z) are directly laminated. By making layer (Y) and layer (Z) adjacent and laminated, the bending resistance of the multilayer structure of the present application is more remarkably exhibited. The reason is not certain, but it is considered that in the case where layer (Y) and layer (Z) are adjacent and laminated, the components of (Z) penetrate into the surface, gaps of layer (Y), and the bending resistance is more remarkably exhibited. From the viewpoint of further improving the bending resistance of the multilayer structure of the present application, the multilayer structure of the present application preferably has a laminated structure in which the substrate (X), layer (Y), and layer (Z) are sequentially laminated. Note that the substrate (X) and layer (Y) can be directly laminated, or can be laminated via an adhesive layer (I).

[0133] The configuration of the multilayer structure of the present application is specifically exemplified below, and each of the specific examples can be a configuration formed by combining a plurality of sets. Note that in the specific examples, the substrate (X) and the other layer (J) are described by the specific resin name. In addition, in the case where layer (Y) / layer (Z) is positioned between layers (substrate (X) and the other layer (J)) described by the specific resin name, the laminated order can be replaced with layer (Z) / layer (Y) such as. Here, " / " means lamination via an adhesive layer or direct lamination.

[0134] (1) layer (Z) / layer (Y) / polyester layer (substrate (X)),

[0135] (2) layer (Z) / layer (Y) / polyester layer / layer (Y) / layer (Z),

[0136] (3) layer (Z) / layer (Y) / polyamide layer,

[0137] (4) layer (Z) / layer (Y) / polyamide layer / layer (Y) / layer (Z),

[0138] (5) layer (Z) / layer (Y) / polyolefin layer,

[0139] (6) layer (Z) / layer (Y) / polyolefin layer / layer (Y) / layer (Z),

[0140] (7) layer (Z) / layer (Y) / hydroxyl-containing polymer layer,

[0141] (8) layer (Z) / layer (Y) / hydroxyl-containing polymer layer / layer (Y) / layer (Z),

[0142] (9) layer (Z) / layer (Y) / paper layer,

[0143] (10) layer (Z) / layer (Y) / paper layer / layer (Y) / layer (Z),

[0144] (11) layer (Z) / layer (Y) / inorganic vapor deposition layer / polyester layer,

[0145] (12) Layer (Z) / Layer (Y) / inorganic vapor-deposited layer / polyamide layer,

[0146] (13) Layer (Z) / Layer (Y) / inorganic vapor-deposited layer / polyolefin layer,

[0147] (14) Layer (Z) / Layer (Y) / inorganic vapor-deposited layer / hydroxyl-containing polymer layer,

[0148] (15) Layer (Z) / Layer (Y) / polyester layer / polyamide layer / polyolefin layer,

[0149] (16) Layer (Z) / Layer (Y) / polyester layer / Layer (Y) / Layer (Z) / polyamide layer / polyolefin layer,

[0150] (17) Polyester layer / Layer (Z) / Layer (Y) / polyester layer / Layer (Y) / Layer (Z) / inorganic vapor-deposited layer / hydroxyl-containing polymer layer / polyolefin layer,

[0151] (18) Polyester layer / Layer (Y) / Layer (Z) / polyamide layer / polyolefin layer,

[0152] (19) Layer (Z) / Layer (Y) / polyamide layer / polyester layer / polyolefin layer,

[0153] (20) Layer (Z) / Layer (Y) / polyamide layer / Layer (Y) / Layer (Z) / polyester layer / polyolefin layer,

[0154] (21) Polyamide layer / Layer (Y) / Layer (Z) / polyester layer / polyolefin layer,

[0155] (22) Layer (Z) / Layer (Y) / polyolefin layer / polyamide layer / polyolefin layer,

[0156] (23) Layer (Z) / Layer (Y) / polyolefin layer / Layer (Y) / Layer (Z) / polyamide layer / polyolefin layer,

[0157] (24) Polyolefin layer / Layer (Y) / Layer (Z) / polyamide layer / polyolefin layer,

[0158] (25) Layer (Z) / Layer (Y) / polyolefin layer / polyolefin layer,

[0159] (26) Layer (Z) / Layer (Y) / polyolefin layer / Layer (Y) / Layer (Z) / polyolefin layer,

[0160] (27) Polyolefin layer / Layer (Z) / Layer (Y) / polyolefin layer,

[0161] (28) Layer (Z) / Layer (Y) / polyester layer / polyolefin layer,

[0162] (29) Layer (Z) / Layer (Y) / Polyester Layer / Layer (Y) / Layer (Z) / Polyolefin Layer,

[0163] (30) Polyester Layer / Layer (Y) / Layer (Z) / Polyolefin Layer,

[0164] (31) Layer (Z) / Layer (Y) / Polyamide Layer / Polyolefin Layer,

[0165] (32) Layer (Z) / Layer (Y) / Polyamide Layer / Layer (Y) / Layer (Z) / Polyolefin Layer,

[0166] (33) Polyamide Layer / Layer (Y) / Layer (Z) / Polyolefin Layer,

[0167] (34) Layer (Z) / Layer (Y) / Polyester Layer / Paper Layer,

[0168] (35) Layer (Z) / Layer (Y) / Polyamide Layer / Paper Layer,

[0169] (36) Layer (Z) / Layer (Y) / Polyolefin Layer / Paper Layer,

[0170] (37) Polyolefin Layer / Paper Layer / Polyolefin Layer / Layer (Y) / Layer (Z) / Polyester Layer / Polyolefin Layer,

[0171] (38) Polyolefin Layer / Paper Layer / Polyolefin Layer / Layer (Y) / Layer (Z) / Polyamide Layer / Polyolefin Layer,

[0172] (39) Polyolefin Layer / Paper Layer / Polyolefin Layer / Layer (Y) / Layer (Z) / Polyolefin Layer,

[0173] (40) Paper Layer / Polyolefin Layer / Layer (Y) / Layer (Z) / Polyester Layer / Polyolefin Layer,

[0174] (41) Polyolefin Layer / Paper Layer / Layer (Z) / Layer (Y) / Polyolefin Layer,

[0175] (42) Paper Layer / Layer (Z) / Layer (Y) / Polyester Layer / Polyolefin Layer,

[0176] (43) Paper Layer / Layer (Z) / Layer (Y) / Polyolefin Layer,

[0177] (44) Layer (Z) / Layer (Y) / Paper Layer / Polyolefin Layer,

[0178] (45) Layer (Z) / Layer (Y) / Polyester Layer / Paper Layer / Polyolefin Layer,

[0179] (46) Polyolefin Layer / Paper Layer / Polyolefin Layer / Layer (Z) / Layer (Y) / Polyolefin Layer / Hydroxyl-Containing Polymer Layer,

[0180] (47) polyolefin layer / paper layer / polyolefin layer / layer (Z) / layer (Y) / polyolefin layer / polyamide layer,

[0181] (48) polyolefin layer / paper layer / polyolefin layer / layer (Z) / layer (Y) / polyolefin layer / polyester layer,

[0182] (49) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyester layer,

[0183] (50) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyester layer / layer (Y) / layer (Z) / inorganic vapor deposition layer,

[0184] (51) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyamide layer,

[0185] (52) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyamide layer / layer (Y) / layer (Z) / inorganic vapor deposition layer,

[0186] (53) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyolefin layer,

[0187] (54) inorganic vapor deposition layer / layer (Z) / layer (Y) / polyolefin layer / layer (Y) / layer (Z) / inorganic vapor deposition layer,

[0188] (55) polyester layer / layer (Y) / layer (Z) / polyamide layer / inorganic vapor deposition layer / hydroxyl group-containing polymer layer / polyolefin layer,

[0189] (56) polyamide layer / layer (Y) / layer (Z) / polyester layer / inorganic vapor deposition layer / hydroxyl group-containing polymer layer / polyolefin layer,

[0190] (57) polyester layer / layer (Y) / layer (Z) / polyester layer / layer (Y) / layer (Z) / inorganic vapor deposition layer / hydroxyl group-containing polymer layer / polyolefin layer,

[0191] (58) polyester layer / layer (Y) / layer (Z) / inorganic vapor deposition layer / polyester layer / polyolefin layer,

[0192] (59) polyester layer / layer (Y) / layer (Z) / inorganic vapor deposition layer / polyester layer / inorganic vapor deposition layer / polyester layer / polyolefin layer

[0193] In the above examples, the inorganic vapor deposition layer is preferably an aluminum vapor deposition layer and / or an aluminum oxide vapor deposition layer. In the above examples, the hydroxyl group-containing polymer layer is preferably an ethylene-vinyl alcohol copolymer. In the above examples, the polyolefin layer is preferably a polyethylene film or a polypropylene film. In the above examples, the polyester layer is preferably a PET film. Furthermore, in the above examples, the polyamide layer is preferably a nylon film.

[0194] [Method for producing a multilayer structure]

[0195] The matters described for the multilayer structure of the present application can be applied to the production method of the present application, and sometimes the repeated description is omitted. Further, the matters described for the production method of the present application can be applied to the multilayer structure of the present application.

[0196] As the production method of the multilayer structure of the present application, a production method including, for example, the following steps can be given: a step (I) of applying a coating liquid (S) containing a metal oxide (A), an inorganic phosphorus compound (BI), and a solvent on a substrate (X), removing the solvent, and forming a layer (Y) precursor layer; a step (II) of applying a coating liquid (T) containing a metal compound (R), a resin (W), and a solvent on the aforementioned layer (Y) precursor layer, removing the solvent, and forming a layer (Z) precursor layer; and a step (III) of heat-treating the layer (Y) precursor layer and the layer (Z) precursor layer, and forming the layer (Y) and the layer (Z). Further, in the case of producing a multilayer structure containing a polymer (F) in the layer (Y), the polymer (F) can be contained in the coating liquid (S), or the polymer (F) can be contained in the coating liquid (T).

[0197] [Step (I)]

[0198] In the step (I), the coating liquid (S) containing the metal oxide (A), the inorganic phosphorus compound (BI), and the solvent is applied on the substrate (X), and then the solvent is removed to form the layer (Y) precursor layer. The coating liquid (S) can be obtained by mixing the metal oxide (A), the inorganic phosphorus compound (BI), and the solvent.

[0199] As a specific method of preparing the coating liquid (S), a method of mixing a dispersion liquid of the metal oxide (A) and a solution containing the inorganic phosphorus compound (BI), a method of adding the inorganic phosphorus compound (BI) to the dispersion liquid of the metal oxide (A) and mixing, and the like can be given. The temperature at the time of mixing in these methods is preferably 50°C or lower, more preferably 30°C or lower, and further preferably 20°C or lower. The coating liquid (S) can contain other compounds (for example, the polymer (F)), and can also contain an acid compound (Q) selected from at least one of acetic acid, hydrochloric acid, nitric acid, trifluoroacetic acid, and trichloroacetic acid, as necessary.

[0200] The dispersion liquid of the metal oxide (A) can be prepared, for example, by mixing the compound (E), water, and an acid catalyst, if necessary, an organic solvent, and subjecting the compound (E) to condensation or hydrolysis condensation, in the manner employed in the known sol-gel method. In the case where the dispersion liquid of the metal oxide (A) is obtained by subjecting the compound (E) to condensation or hydrolysis condensation, the resulting dispersion liquid can be subjected to a specific treatment (sol-gel in the presence of the aforementioned acid compound (Q), etc.), if necessary. The solvent used in the preparation of the dispersion liquid of the metal oxide (A) is not particularly limited, and is preferably an alcohol such as methanol, ethanol, isopropanol, etc.; water; or a mixed solvent thereof.

[0201] As the solvent used in the solution containing the inorganic phosphorus compound (BI), any solvent can be appropriately selected depending on the kind of the inorganic phosphorus compound (BI), and it is preferred to contain water. The solvent can also contain an organic solvent (e.g., an alcohol such as methanol, etc.) as long as it does not hinder the dissolution of the inorganic phosphorus compound (BI).

[0202] The solid content concentration of the coating liquid (S) is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and further preferably 3 to 10% by mass, from the viewpoints of the storage stability of the coating liquid and the coatability onto the substrate. The aforementioned solid content concentration can be calculated, for example, by dividing the mass of the solid content remaining after distilling off the solvent of the coating liquid (S) by the mass of the coating liquid (S) subjected to the treatment.

[0203] The viscosity of the coating liquid (S) measured with a Brookfield-type rotational viscometer (SB-type viscometer: No. 3 rotor, rotation speed 60 rpm) is preferably 3000 mPa-s or less, more preferably 2500 mPa-s or less, and further preferably 2000 mPa-s or less at the temperature at which the coating is performed. By making the viscosity 3000 mPa-s or less, the leveling property of the coating liquid (S) is improved, and a multilayer structure having a more excellent appearance can be obtained. Further, the viscosity of the coating liquid (S) is preferably 50 mPa-s or more, more preferably 100 mPa-s or more, and further preferably 200 mPa-s or more.

[0204] In the coating liquid (S), the molar ratio of aluminum atoms to phosphorus atoms is preferably in the range of aluminum atoms: phosphorus atoms = 1.0: 1.0 to 3.6: 1.0, more preferably in the range of 1.1: 1.0 to 3.0: 1.0, and particularly preferably in the range of 1.11: 1.00 to 1.50: 1.00. The molar ratio of aluminum atoms to phosphorus atoms can be calculated by performing fluorescent X-ray analysis of the dry solid of the coating liquid (S).

[0205] The coating of the coating liquid (S) is not particularly limited, and a publicly known method can be used. As the coating method, for example, a flow casting method, an immersion method, a roll coating method, a gravure coating method, a screen printing method, a reverse coating method, a spray coating method, a kiss coating method, a slot die coating method, a metering rod coating method, a coating method using a sealing doctor blade in combination, a curtain coating method, a bar coating method, and the like can be given.

[0206] The method for removing the solvent after the coating of the coating liquid (S) (drying treatment) is not particularly limited, and a publicly known drying method can be used. As the drying method, for example, a hot air drying method, a hot roll contact method, an infrared heating method, a microwave heating method, and the like can be given.

[0207] The drying temperature is preferably lower than the flow initiation temperature of the base material (X). The drying temperature after the coating of the coating liquid (S) can be, for example, about 60 to 180°C, more preferably 60°C or higher and less than 140°C, further preferably 70°C or higher and less than 130°C, particularly preferably 80°C or higher and less than 120°C. The drying time is not particularly limited, and is preferably 1 second or longer and less than 1 hour, more preferably 5 seconds or longer and less than 15 minutes, further preferably 5 seconds or longer and less than 300 seconds. Particularly, in the case where the drying temperature is 100°C or higher (for example, 100 to 140°C), the drying time is preferably 1 second or longer and less than 4 minutes, more preferably 5 seconds or longer and less than 4 minutes, further preferably 5 seconds or longer and less than 3 minutes. In the case where the drying temperature is lower than 100°C (for example, 60 to 99°C), the drying time is preferably 3 minutes or longer and less than 1 hour, more preferably 6 minutes or longer and less than 30 minutes, further preferably 8 minutes or longer and less than 25 minutes. When the drying treatment conditions of the coating liquid (S) are within the above range, a multilayer structure having a more excellent gas barrier property tends to be obtained. By removing the solvent through the above drying, a layer (Y) precursor layer is formed.

[0208] [Step (II)]

[0209] In Step (II), after the coating of the coating liquid (T) containing the metal compound (R), the resin (W), and the solvent on the layer (Y) precursor layer obtained in Step (I), the solvent is removed, and a layer (Z) precursor is formed.

[0210] The coating liquid (T) can be prepared, for example, by a method in which a liquid containing the metal compound (R) and the solvent is added to a liquid containing the resin (W) and the solvent, or a method in which the solvent is added to the metal compound (R), and then an acid catalyst and water are added, and a hydrolysis condensation is performed using a publicly known sol-gel method to form a hydrolysis condensate, which is then added to a solution containing the resin (W) and the solvent. As the solvent used in the coating liquid (T), there is no particular limitation, and an alcohol such as methanol, ethanol, isopropanol, and the like; water; or a mixed solvent thereof is preferred.

[0211] As the acid catalyst in the case of the hydrolysis condensation, a publicly known acid can be used, and for example, hydrochloric acid, sulfuric acid, nitric acid, p-toluenesulfonic acid, benzoic acid, acetic acid, lactic acid, butyric acid, carbonic acid, oxalic acid, maleic acid, and the like can be used. Among them, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, lactic acid, and butyric acid are particularly preferable. The preferable amount of use of the acid catalyst varies depending on the kind of the acid used, and is preferably in the range of 1 x 10 -5 ~ 10 moles, more preferably in the range of 1 x 10 -4 ~ 5 moles, further preferably in the range of 5 x 10 -4 ~ 1 moles, with respect to 1 mole of the metal atom of the metal compound (R).

[0212] The preferable amount of use of water in the case of the hydrolysis condensation varies depending on the kind of the metal compound (R) used, and is preferably in the range of 0.05 ~ 10 moles, more preferably in the range of 0.1 ~ 5 moles, further preferably in the range of 0.2 ~ 3 moles, with respect to 1 mole of the hydrolyzable specific group of the metal compound (R) used in the step (II).

[0213] In the preparation of the coating solution (T) of the step (II), the temperature is not particularly limited, and is usually in the range of 2 ~ 100°C, preferably in the range of 4 ~ 60°C, more preferably in the range of 5 ~ 40°C. The time varies depending on the amount, kind of the resin (W), the metal compound (R), the solvent, and further depending on the reaction conditions (amount, kind of the acid catalyst, and the like) in the case of the hydrolysis condensation, but is usually in the range of 0.01 ~ 60 hours, preferably in the range of 0.1 ~ 12 hours, more preferably in the range of 0.1 ~ 6 hours. Further, the preparation can be performed under an atmosphere of various gases such as air, carbon dioxide, nitrogen, argon, and the like.

[0214] The solid content concentration of the coating solution (T) is preferably in the range of 0.01 ~ 10 mass%, more preferably in the range of 0.05 ~ 7 mass%, further preferably in the range of 0.1 ~ 5 mass%, from the viewpoints of the storage stability of the coating solution and the coatability for the substrate. The aforementioned solid content concentration can be calculated, for example, by dividing the mass of the solid content remaining after the removal by distillation with the solvent of the coating solution (T) by the mass of the coating solution (T) subjected to the treatment.

[0215] The coating of the coating solution (S) is not particularly limited, and a publicly known method can be employed. As the coating method, for example, a flow casting method, an immersion method, a roll coating method, a gravure coating method, a screen printing method, a reverse coating method, a spray coating method, a kiss coating method, a die coating method, a metering rod coating method, a coating method using a sealing doctor blade in combination, a curtain coating method, a bar coating method, and the like can be mentioned.

[0216] The thickness of the layer (Z) formed after applying the coating liquid (T) on the layer (Y) precursor layer can be controlled by the solid content concentration of the coating liquid (T) or the application method. For example, in the case of a gravure coating method, the groove volume of the gravure roll can be changed.

[0217] The method for removing the solvent of the coating liquid (T) after application on the substrate (X) is not particularly limited, and a publicly known drying method can be used. As the drying method, for example, a hot air drying method, a hot roll contact method, an infrared heating method, a microwave heating method, and the like can be given.

[0218] [Step (III)]

[0219] In Step (III), the layer (Y) precursor layer and the layer (Z) precursor layer formed in Step (II) are subjected to heat treatment to form the layer (Y) and the layer (Z). In Step (III), the reaction to generate the reaction product (D) and the reaction of the metal compound (R) with the resin (W) are performed. In order to sufficiently perform the reaction, the temperature of the heat treatment is preferably 140°C or higher, more preferably 170°C or higher, further preferably 180°C or higher, and particularly preferably 190°C or higher. When the temperature of the heat treatment is low, the time taken to obtain a sufficient reaction rate becomes long, which is a cause of a decrease in productivity. The temperature of the heat treatment varies depending on the kind of the substrate (X) and the like, and for example, when a thermoplastic resin film formed of a polyamide-based resin is used as the substrate (X), the temperature of the heat treatment is preferably 270°C or lower. Further, when a thermoplastic resin film formed of a polyester-based resin is used as the substrate (X), the temperature of the heat treatment is preferably 240°C or lower. The heat treatment can be performed in an air atmosphere, a nitrogen atmosphere, an argon atmosphere, or the like. The heat treatment time is preferably 1 second to 1 hour, more preferably 1 second to 15 minutes, and further preferably 5 to 300 seconds.

[0220] Step (III) preferably includes a first heat treatment step (III-1) and a second heat treatment step (III-2). When the heat treatment is performed in two or more stages, the temperature of the heat treatment in the second stage (hereinafter referred to as the second heat treatment) is preferably higher than the temperature of the heat treatment in the first stage (hereinafter referred to as the first heat treatment), more preferably 15°C or higher than the temperature of the first heat treatment, further preferably 20°C or higher, and particularly preferably 30°C or higher.

[0221] Further, from the viewpoint of obtaining a multilayer structure having good properties, the heat treatment temperature of Step (III) (the first heat treatment temperature in the case of heat treatment in two or more stages) is preferably higher than the drying temperature of Step (II), preferably 30°C or higher, more preferably 50°C or higher, further preferably 55°C or higher, and particularly preferably 60°C or higher.

[0222] In the case where the heat treatment of step (III) is performed in two or more stages, the temperature of the first heat treatment is preferably 140°C or higher and less than 200°C, and the temperature of the second heat treatment is more preferably 180°C or higher and 270°C or lower, and the temperature of the second heat treatment is preferably higher than the temperature of the first heat treatment, more preferably 15°C or higher, and further preferably 25°C or higher. In particular, in the case where the heat treatment temperature is 200°C or higher, the heat treatment time is preferably 0.1 seconds to 10 minutes, more preferably 0.5 seconds to 5 minutes, and further preferably 1 second to 3 minutes. In the case where the heat treatment temperature is less than 200°C, the heat treatment time is preferably 1 second to 15 minutes, more preferably 5 seconds to 10 minutes, and further preferably 10 seconds to 5 minutes.

[0223] Step (II) can be step (II') in which a coating liquid (T) is applied to the layer (Y) obtained in step (III) or the layer (Y) precursor layer after step (III-1), and a drying treatment is performed. In the case where step (II') is performed after step (III), it is preferable to perform a heat treatment under the same conditions as step (III) after the drying treatment of step (II'). In the case where step (II') is performed after step (III-1), it is preferable to perform step (III-2) after the drying treatment of step (II').

[0224] [USES]

[0225] The multilayer structure of the present application has excellent barrier properties, and thus can be used for various uses of packaging materials, electronic device protective sheets, and moisture-proof sheets. In addition, from the viewpoint of excellent bending resistance, it is suitable for use as a packaging material, a vacuum packaging bag (an outer packaging material for a vacuum heat insulator). Here, excellent boiling resistance can be considered as a property of maintaining good appearance and gas barrier properties even when exposed to severe conditions. Thus, from the viewpoint of maintaining excellent properties (appearance and gas barrier properties) even in a severe external environment, it is suitable for use as an outer packaging material for a vacuum heat insulator. Further, the multilayer structure of the present application is also suitable for use as a protective sheet for an electronic device.

[0226] [PACKAGING MATERIAL]

[0227] The packaging material of the present application can be composed of only the multilayer structure of the present application, or can be composed of the multilayer structure of the present application and other members. For example, 50% to 100% of the area of a packaging bag can be composed of the multilayer structure. The same applies to a substance other than a packaging bag (for example, a container, a lid material). The packaging material using the preferred embodiment of the present application has barrier properties against inorganic gases (for example, hydrogen, helium, nitrogen, oxygen, carbon dioxide), natural gases, water vapor, and organic compounds (for example, ethanol, gasoline vapor) that are liquid at normal temperature and pressure.

[0228] The packaging material of the present application can be produced by a variety of methods. For example, a container (packaging material) can be produced by joining a sheet-like multilayer structure or a film material containing the same (hereinafter referred to as "film material") into a prescribed container shape. The molding method can be exemplified by thermoforming, injection molding, extrusion blow molding, and the like. Further, a container (packaging material) can be produced by forming the layer (Z) and the layer (Y) on a base material (X) molded into a prescribed container shape.

[0229] The packaging material according to the present application is preferably used as a food packaging material. Further, the packaging material according to the present application can be preferably used as a packaging material for packaging agricultural chemicals, pharmaceuticals and the like; medical devices; mechanical parts, precision materials and the like; clothing and the like, in addition to the food packaging material.

[0230] As an article using the packaging material of the present application, a vertical form, fill, and seal bag, a vacuum packaging bag, a pouch, a laminated tube container, an infusion bag, a lid material for a container, a paper container, a tape, an in-mold label container, or a vacuum heat insulator, and the like can be exemplified.

[0231] The vertical form, fill, and seal bag is a bag obtained by forming a bag from the multilayer structure (film material) of the present application using a vertical form, fill, and seal machine (also referred to as a vertical form, fill, and seal packaging machine, and the like). The vertical form, fill, and seal machine, for example, holds a supplied film material so as to form opposing faces, seals (joins) the side portions and the bottom portion thereof, forms a bag having an upper opening, supplies a content from the upper portion of the bag, and fills the content into the inside thereof. Next, the vertical form, fill, and seal machine seals the upper portion of the bag, cuts the upper portion thereof, and discharges the vertical form, fill, and seal bag.

[0232] The vacuum packaging bag is a bag obtained by forming a bag from the multilayer structure of the present application and used in a state in which the inside of the bag is reduced in pressure. Since the inside of the bag is reduced in pressure, the film material that separates the inside of the bag from the outside of the bag is deformed in contact with the content accommodated in the bag, for the vacuum packaging bag. The content is typically a food such as a corn on the cob (corn), beans, bamboo shoots, potatoes, chestnuts, tea leaves, meat, fish, snacks, and the like, or a core material contained for use as a vacuum heat insulator.

[0233] The pouch bag is a container having the multilayer structure (film material) of the present application as a partition wall that separates the inside in which a content is accommodated from the outside. The pouch bag is suitable for the accommodation of a liquid or paste content, but can also be used for the accommodation of a solid content. The content is typically a beverage, a condiment, a liquid food or other food, and a lotion, a liquid soap, or other daily necessities.

[0234] A laminated tube container has: a main body portion having the multilayer structure (laminated film) of the present application as a partition wall that separates the inside of the container from the outside; and a dispensing portion for dispensing the contents held in the inside of the container. The main body portion of the laminated tube container has, for example, a closed cylindrical shape at one end portion, and the dispensing portion is provided at the other end portion.

[0235] An infusion bag is a bag (pouch) for containing an infusion agent such as an amino acid infusion agent, an electrolyte infusion agent, a sugar infusion agent, a fat emulsion for infusion, and the like as contents. The infusion bag has, in addition to a bag body that contains the contents, a stopper member. Further, the infusion bag can have a hanging hole for hanging the bag. In the infusion bag, a film material that separates the inside for containing the infusion agent from the outside is provided with the multilayer structure of the present application.

[0236] A container lid material has a film material (multilayer structure of the present application) that functions as a part of a partition wall that separates the inside of a container from the outside of the container in a state where the container is formed by combining a container body. The container lid material is combined with the container body in a manner to seal the opening portion of the container body by heat sealing, bonding (sealing) using an adhesive, or the like, and forms a container (lidded container) having a closed space in the inside. The container lid material is generally bonded to the container body at a peripheral portion thereof. In this case, a central portion surrounded by the peripheral portion faces the inside space of the container. The container body is, for example, a shaped body having a cup shape, a disc shape, or another shape, and has a flange portion, a wall portion, or the like for sealing the container lid material.

[0237] A paper container is a container that includes a paper layer as a partition wall that separates the inside for containing contents from the outside. The paper container has, for example, a shape of a gable-top type, a brick type, or the like. These shapes have a bottom wall portion for standing alone in the paper container.

[0238] A vacuum heat insulator has a vacuum packaging bag, and a core material provided in the inside surrounded by the vacuum packaging bag, and is a heat insulator in which the inside in which the core material is provided is reduced in pressure. As the core material, a powder such as pearlite powder, a fibrous material such as glass wool, a resin foam such as polyurethane foam, a hollow container, a honeycomb structure, or the like can be used. In the vacuum heat insulator, the vacuum packaging bag that functions as a partition wall is provided with the multilayer structure.

[0239] As a layer configuration of the multilayer structure suitable for use in the vacuum heat insulator, for example, the following configurations can be given.

[0240] (1) Polyolefin layer / Ethylene-vinyl alcohol copolymer layer / Inorganic vapor deposition layer / Polyamide layer / Layer (Z) / Layer (Y) / Polyester layer

[0241] (2) Polyolefin layer / Inorganic vapor deposition layer / Polyester layer / Inorganic vapor deposition layer / Polyester layer / Layer (Z) / Layer (Y) / Polyester layer

[0242] (3) polyolefin layer / ethylene-vinyl alcohol copolymer layer / inorganic vapor deposition layer / layer (Z) / layer (Y) / polyester layer / layer (Z) / layer (Y) / polyester layer

[0243] (4) polyolefin layer / inorganic vapor deposition layer / polyester layer / layer (Z) / layer (Y) / polyester layer / polyester layer / layer (Z) / layer (Y) / polyester layer

[0244] (5) polyolefin layer / polyamide layer / inorganic vapor deposition layer / polyester layer / layer (Z) / layer (Y) / polyester layer

[0245] (6) polyolefin layer / ethylene-vinyl alcohol copolymer layer / inorganic vapor deposition layer / inorganic vapor deposition layer / polyester layer / layer (Z) / layer (Y) / polyester layer

[0246] By being combined with the inorganic vapor deposition layer, the gas barrier property is improved, and the decrease in the thermal conductivity can be suppressed. Further, the above polyolefin layer can be changed to an ethylene-vinyl alcohol copolymer layer, and by being changed to an ethylene-vinyl alcohol copolymer layer, the effect of suppressing the decrease in the thermal conductivity at high temperatures is obtained. In the case where the above layer configuration is used as an outer packaging material for a vacuum adiabatic body, it is preferable that the polyolefin layer side be provided as the inner layer (heat-seal layer) and the polyester layer side be provided as the outer layer. By the above layer configuration, the tendency of the deterioration of the inner layer side due to external gas such as water vapor caused by long-term use can be suppressed, and thus it is preferable. Further, as the material that can be used in the above layer configuration, there is no particular limitation, and the resins described in the present application examples can be suitably used.

[0247] In the above molded article (for example, a stand-up pouch, a bag, or the like), heat-sealing is sometimes performed. In the case where heat-sealing is performed, a heat-sealable layer is required to be provided on the side of the molded article as the inner side, or on both the side of the molded article as the inner side and the side of the molded article as the outer side. In the case where the heat-sealable layer is provided on the side of the molded article (bag) as the inner side, the seal of the main body portion is usually formed as a herringbone seal. In the case where the heat-sealable layer is provided on both the side of the molded article as the inner side and the side of the molded article as the outer side, the seal of the main body portion is usually formed as an envelope seal. As the heat-sealable layer, a polyolefin layer is preferable.

[0248] The protective sheet for an electronic device of the present application contains the multilayer structure of the present application, and can be constituted only of the multilayer structure of the present application. The protective sheet for an electronic device is used for the purpose of protecting an electronic device from the influence from the external environment, and for example, the protective sheet of the present application can be provided on the surface of a sealing material that is sealed in a manner of covering the surface of the electronic device body. That is, the protective sheet of the present application is usually provided on the surface of the electronic device body via a sealing material. As the electronic device body, there is no particular limitation, and for example, a photoelectric conversion device, an information display device, or a lighting device can be cited.

[0249] The protective sheet of the electronic device of the present application can contain, for example, a surface protective layer disposed on one surface or both surfaces of the multilayer structure. As the surface protective layer, a layer formed of a resin that is difficult to damage is preferable. Further, the surface protective layer of a device that is sometimes used outdoors, such as a solar cell, is preferably formed of a resin having high weather resistance (e.g., light resistance). Further, in the case of protecting a surface that needs to be transparent, a surface protective layer having high transparency is preferable. As the material of the surface protective layer (surface protective film), poly(meth)acrylate, polycarbonate, polyethylene terephthalate, polyethylene-2,6-naphthalate, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and the like can be given. One example of the protective sheet contains a poly(meth)acrylate layer disposed on one surface.

[0250] In order to improve the durability of the surface protective layer, various additives (e.g., ultraviolet absorbers) can be added to the surface protective layer. One preferable example of the surface protective layer having high weather resistance is an acrylic resin layer to which an ultraviolet absorber is added. As the ultraviolet absorber, ultraviolet absorbers of benzotriazole-based, benzophenone-based, salicylate-based, cyanoacrylate-based, nickel-based, and triazine-based can be given, but are not limited to these. Further, other stabilizers, light stabilizers, antioxidants, and the like can be used in combination.

[0251] Further, the multilayer structure of the present application can also be effectively used as a moisture-proof sheet. For example, in the decorative panel use, by making it adhere to the surface of a decorative panel used in a door panel or the like in a room, warping due to reasons such as moisture absorption / desorption caused by changes in the temperature and humidity in the room can be prevented. Examples

[0252] Next, the present application will be further specifically described by citing examples, but the present application is not limited by any of these examples, and various modifications can be made by those having ordinary knowledge in the art within the scope of the technical idea of the present application. The analysis and evaluation in the following examples and comparative examples were performed as follows.

[0253] Materials used in the examples and comparative examples are shown.

[0254] PET12: Biaxially stretched polyethylene terephthalate film; manufactured by Toray Industries, Inc., "Lumirror (trademark) P60" (trade name), average thickness 12 μm

[0255] ONY15: Biaxially stretched nylon film; "Emblem (trademark) ONBC" (trade name) by Unitika Ltd., average thickness 15 μm

[0256] CPP50: Unstretched polypropylene film; "RXC-22" (trade name) by Mitsui Chemicals Toagosei, Inc., average thickness 50 μm

[0257] CPP100: Unstretched polypropylene film; "RXC-22" (trade name) by Mitsui Chemicals Toagosei, Inc., average thickness 100 μm

[0258] PET50: Polyethylene terephthalate film with improved adhesion to ethylene-vinyl acetate copolymer; "Shine Beam (registered trademark) Q1A15" (trade name) by Toyobo Co., Ltd., average thickness 50 μm

[0259] VM-XL: Aluminum vapor-deposited biaxially stretched EVOH film; "VM-XL" (trade name) by Kuraray Co., Ltd., average thickness 12 μm

[0260] LLDPE50: Linear low-density polyethylene film; "Unilac LS-760C" by Shikoku Uniteka Co., Ltd., average thickness 50 μm

[0261] PVA60-98: Polyvinyl alcohol; "Kuraray Poval (registered trademark) 60-98" (trade name) by Kuraray Co., Ltd., saponification degree: 98.0 to 99.0 mol%, viscosity (4%, 20°C): 54.0 to 66.0 mPa-s

[0262] PVA28-98: Polyvinyl alcohol; "Kuraray Poval (registered trademark) 28-98" (trade name) by Kuraray Co., Ltd., saponification degree: 98.0 to 99.0 mol%, viscosity (4%, 20°C): 25.0 to 31.0 mPa-s

[0263] GPTMOS: 3-glycidoxypropyltrimethoxysilane; "LS-2940" (trade name) by Shin-Etsu Chemical Co., Ltd.

[0264] TC-315: Organic titanium compound (titanium lactate solution); "Orgatics TC-315" (trade name) by Matsubayashi Fine Chemical Co., Ltd.: solid content concentration 35 to 45%

[0265] TMOS: Trimethoxysilane; "LS-540" (trade name) by Shin-Etsu Chemical Co., Ltd.

[0266] NTMOS: 3-Aminopropyltrimethoxysilane; manufactured by Shin-Etsu Chemical Co., Ltd. as "KBM-903" (trade name).

[0267] [Evaluation Method]

[0268] (1) Determination of the average thickness of layer (Y) and layer (Z)

[0269] The multilayer structures obtained in the examples and comparative examples were cut using a focused ion beam (FIB) to prepare cross-sectional sections for observation. The prepared sections were fixed to a sample stage with a carbon ribbon and subjected to platinum ion sputtering at an accelerating voltage of 30 kV for 30 seconds. The cross-sections of the multilayer structures were observed using a field emission transmission electron microscope, and the average thicknesses of layers (Y) and (Z) were calculated. The measurement conditions are described below.

[0270] Device: JEM-2100F manufactured by Nippon Electronics Co., Ltd.

[0271] Accelerating voltage: 200kV

[0272] Multiplier: 250,000x.

[0273] (2) Determination of oxygen permeability of multilayer structures

[0274] The multilayer structures obtained in the examples and comparative examples were mounted in an oxygen permeability measuring device with the substrate facing the carrier gas side, and the oxygen permeability was measured by the isobaric method according to JIS K7126:2006. The measurement conditions are as described below.

[0275] Device: MOCON OX-TRAN2 / 21 manufactured by MOCON Corporation

[0276] Temperature: 20℃

[0277] Humidity on the oxygen supply side: 85%RH

[0278] Carrier gas side humidity: 85%RH

[0279] Carrier gas flow rate: 10 mL / min

[0280] Oxygen pressure: 1.0 atm

[0281] Carrier gas pressure: 1.0 atm.

[0282] (3) Measurement of moisture permeability of multi-layered structures

[0283] The multilayer structures obtained in the examples and comparative examples were mounted in a water vapor transmission rate measuring device with the substrate layer facing the carrier gas side, and the water vapor transmission rate (water vapor transmission rate) was measured by the isobaric method according to JIS K7129B:2008. The measurement conditions are as described below.

[0284] Device: MOCON PERMATRAN W3 / 33, manufactured by MOCON.

[0285] Temperature: 40℃

[0286] Humidity on the water vapor supply side: 90%RH

[0287] Carrier gas side humidity: 0%RH

[0288] Carrier gas flow rate: 50 mL / min.

[0289] (4) Determination of oxygen permeability and moisture permeability after bending treatment

[0290] The multilayer structures obtained in the examples and comparative examples were cut into 210mm × 297mm (A4 size) pieces and bent for 50 cycles using a Gelbo Filter Tester (manufactured by Rigaku Kogyo Co., Ltd.) according to ASTM F-392. For the central part of the bent multilayer structure, oxygen permeability and moisture permeability were measured according to the methods described in the above evaluation methods (2) and (3).

[0291] (5) Appearance evaluation after steaming

[0292] The multilayer structures obtained in the examples and comparative examples were cut into 12mm × 12mm sizes. Two pieces of this multilayer structure were made, with the CPP50 sides overlapping, and three sides were heat-sealed. Then, 80mL of water was filled into the soft bag, and the remaining side was heat-sealed. Next, the resulting soft bag was subjected to a boiling treatment (hot water storage type) under the following conditions. For the boiled soft bag, A is defined as no appearance defects caused by interlayer delamination on the entire surface, B is defined as some appearance defects caused by interlayer delamination, and C is defined as appearance defects caused by interlayer delamination on the entire surface.

[0293] Retort treatment device: フレーバーエースRSC-60 manufactured by Hisaka Manufacturing Co., Ltd.

[0294] Temperature: 120℃

[0295] Time: 30 minutes

[0296] Pressure: 0.15 MPaG.

[0297] (6) Molar ratio M MR / M Al Calculated

[0298] A 0.5 g sample of the multilayer structure obtained in the examples and comparative examples was taken in a platinum crucible, and 1 mL of sulfuric acid and 1 mL of nitric acid were added. The sample was then ashed using a hot plate, electric heater, and heat transfer furnace. After ashing, 0.3 g of lithium tetraborate was added and melted in a high-frequency melting apparatus. After melting, 10 mL of nitric acid was added in two 5 mL portions to dissolve the material. The final volume was 100 mL, and the amount of metal contained in the multilayer structure was quantified using ICP emission spectroscopy. The measurement conditions are described below.

[0299] Device: Thermo Fisher Scientific iCAP6500Duo

[0300] RF power: 1150W

[0301] Pump flow rate: 50 rpm; Auxiliary gas flow rate (argon): 0.5 L / min

[0302] Carrier gas flow rate (argon): 0.7 L / min

[0303] Coolant gas: 12L / min.

[0304] The amount of metal contained in the substrate (X) was also quantified using the same method as for the multilayer structure described above. Based on this result, the amount of metal contained in layers (Y) and (Z) was calculated by subtracting the amount of metal contained in the substrate (X) from the amount of metal contained in the multilayer structure. Furthermore, these were converted to molar amounts to calculate the number of metal atoms (M) per unit area constituting layer (Z). R The number of moles (M) MR The number of moles of aluminum atoms contained in layer (Y) (M) Al The molar ratio M MR / M Al .

[0305] (7) Molar ratio M MR / M C Calculated

[0306] The surface of the layer (Z) of the multilayer structures obtained in the examples and comparative examples was calculated using X-ray photoelectron spectroscopy (XPS). X-ray photoelectron spectroscopy (XPS) was performed using a scanning X-ray photoelectron spectroscopy analyzer (PHI Quantera SXM, manufactured by Alback Fairy Co., Ltd.). The XPS was calculated at 1×10⁻⁶. -6 Analysis was performed in a vacuum of Pa, within a 1000 μm × 1000 μm area, at a receiving angle of 90°. Based on these results, the number of metal atoms (M) constituting layer (Z) was calculated. R The number of moles (M) MR The number of moles of carbon atoms contained in layer (Z) (M) C The molar ratio MMR / M C Note that, in the case where the surface layer of the layer (Z) of the composite structure is contaminated, argon sputtering treatment is performed, and the inside of the layer (Z) is taken as the analysis target.

[0307] (8) Measurement of infrared absorption spectrum

[0308] The layer (Y) side (the side opposite to the substrate (X)) of the multilayer structure obtained in the examples and comparative examples was measured using a Fourier transform infrared spectrophotometer by the attenuated total reflection method. The measurement conditions were as described below.

[0309] Apparatus: Spectrum One manufactured by PerkinElmer Inc.

[0310] Measurement mode: attenuated total reflection method

[0311] Measurement region: 800 to 1400 cm -1 .

[0312] <Manufacturing Example of Coating Liquid (S-1)>

[0313] Distilled water 230 parts by mass was warmed to 70°C while being stirred. Aluminum triisopropoxide 88 parts by mass was added dropwise to the distilled water over a period of 1 hour, and the liquid temperature was slowly increased to 95°C, and the isopropyl alcohol produced was distilled off, whereby hydrolytic condensation was performed. In the obtained liquid, 4.0 parts by mass of a 60% nitric acid aqueous solution was added, and stirring was performed at 95°C for 3 hours, whereby the agglomerates of the particles of the hydrolytic condensate were deflocculated. Then, the liquid was concentrated so that the solid content concentration became 10% by mass in terms of aluminum oxide, and a solution was obtained. To 22.50 parts by mass of the thus obtained solution, 54.29 parts by mass of distilled water and 18.80 parts by mass of methanol were added, and stirring was performed to achieve homogeneity, whereby a dispersion liquid was obtained. Subsequently, while maintaining the liquid temperature at 15°C, the dispersion liquid was added dropwise while stirring, and 4.41 parts by mass of a 85% phosphoric acid aqueous solution was added. Further, 18.80 parts by mass of a methanol solution was added, and stirring was continued at 15°C until the viscosity reached 1500 mPa s, and a target coating liquid (S-1) was obtained. The molar ratio of aluminum atoms to phosphorus atoms in the coating liquid (S-1) was aluminum atoms: phosphorus atoms = 1.15: 1.00.

[0314] <Manufacturing Example of Coating Liquid (T-1)>

[0315] A GPTMOS methanol solution was prepared by dissolving 45.45 parts by mass of GPTMOS in 45.45 parts by mass of methanol. While maintaining the temperature of the GPTMOS methanol solution at 10°C or lower, 9.10 parts by mass of 0.2 N hydrochloric acid was added while stirring, and a hydrolysis and condensation reaction was performed at 10°C for 30 minutes, thereby obtaining a solution (T-l-l). Next, 51.48 parts by mass of a 5 wt% aqueous solution of polyvinyl alcohol ("PVA60-98" manufactured by Kuraray Co., Ltd.) was diluted with 28.93 parts by mass of distilled water and 19.36 parts by mass of methanol, and 0.23 parts by mass of the solution (T-l-l) was added while stirring, and the mixture was stirred at room temperature for 30 minutes, thereby obtaining a coating liquid (T-l) having a solid content concentration of 2.6%.

[0316] <Manufacturing Examples of Coating Liquids (T-2) to (T-4), (CT-3) to (CT-4)>

[0317] Except that the type of the hydroxyl group-containing resin (W), the type of the metal compound (R), and the molar ratio (M MR / M C Coating liquids (T-2) to (T-4), (CT-3) to (CT-4) were obtained in the same manner as in the preparation of the coating liquid (T-l), except that the type of the hydroxyl group-containing resin (W), the type of the metal compound (R), and the molar ratio (M

[0318] <Manufacturing Example of Coating Liquid (T-5)>

[0319] After 52.00 parts by mass of a 5 wt% aqueous solution of polyvinyl alcohol ("PVA60-98" manufactured by Kuraray Co., Ltd.) was diluted with 28.44 parts by mass of distilled water and 19.46 parts by mass of methanol, 0.15 parts by mass of the organic titanium compound TC-315 was added while stirring, and the mixture was stirred at room temperature for 30 minutes, thereby obtaining a coating liquid (T-5) having a solid content concentration of 2.6%.

[0320] <Manufacturing Examples of Coating Liquids (T-6) to (T-9), (CT-5) to (CT-6)>

[0321] Except that the type of the hydroxyl group-containing resin (W), the type of the metal compound (R), and the molar ratio (M MR / M C Coating liquids (T-6) to (T-9), (CT-5) to (CT-6) were obtained in the same manner as in the preparation of the coating liquid (T-5), except that the type of the hydroxyl group-containing resin (W), the type of the metal compound (R), and the molar ratio (M

[0322] <Manufacturing Example of Coating Liquid (T-10)>

[0323] A TMOS methanol solution was prepared by dissolving TMOS 44.83 parts by mass in methanol 44.83 parts by mass. The temperature of the TMOS methanol solution was maintained at 10°C or less while adding 0.2 N hydrochloric acid 10.34 parts by mass, and a hydrolysis and condensation reaction was carried out at 10°C for 30 minutes with stirring, whereby a solution (T-10-1) was obtained. Next, a 5 wt% polyvinyl alcohol (manufactured by Kuraray Co., Ltd., "PVA60-98") aqueous solution 51.47 parts by mass was diluted with distilled water 28.97 parts by mass and methanol 19.41 parts by mass, and then 0.15 parts by mass of the solution (T-10-1) was added with stirring, and stirred at room temperature for 30 minutes, whereby a coating liquid (T-10) having a solid content concentration of 2.6% was obtained.

[0324] <Example of Production of Coating Liquid (T-11)>

[0325] A NTMOS methanol solution was prepared by dissolving NTMOS 44.44 parts by mass in methanol 44.44 parts by mass. The temperature of the NTMOS methanol solution was maintained at 10°C or less while adding 0.2 N hydrochloric acid 11.12 parts by mass, and a hydrolysis and condensation reaction was carried out at 10°C for 30 minutes with stirring, whereby a solution (T-11-1) was obtained. Next, a 5 wt% polyvinyl alcohol (manufactured by Kuraray Co., Ltd., "PVA60-98") aqueous solution 51.73 parts by mass was diluted with distilled water 28.74 parts by mass and methanol 19.44 parts by mass, and then 0.18 parts by mass of the solution (T-11-1) was added with stirring, and stirred at room temperature for 30 minutes, whereby a coating liquid (T-11) having a solid content concentration of 2.6% was obtained.

[0326] <Example of Production of Coating Liquid (CT-1)>

[0327] A 5 wt% polyvinyl alcohol (manufactured by Kuraray Co., Ltd., "PVA60-98") aqueous solution 52.00 parts by mass was diluted with distilled water 28.44 parts by mass and methanol 19.46 parts by mass, and stirred at room temperature for 30 minutes, whereby a coating liquid (CT-1) having a solid content concentration of 2.6% was obtained.

[0328] <Example of Production of Coating Liquid (CT-2)>

[0329] A coating liquid (CT-2) was obtained in the same manner as in the production of the coating liquid (CT-1), except that the type of the hydroxyl group-containing resin (W) was changed as shown in Table 1.

[0330] <Example of Production of Coating Liquid (CT-7)>

[0331] A TMOS methanol solution was prepared by dissolving tetramethoxysilane (TMOS) 4.82 parts by mass in methanol 4.82 parts by mass. The temperature of the TMOS methanol solution was maintained at 10°C or lower while adding 0.2N hydrochloric acid 1.11 parts by mass, and a hydrolysis and condensation reaction was performed at 10°C for 30 minutes with stirring. Next, after dilution with distilled water 52.58 parts by mass, 5% polyvinyl alcohol (Kuraray Co., Ltd. "PVA60-98") aqueous solution 13.00 parts by mass, methanol 23.49 parts by mass, and GPTMOS 0.19 parts by mass were added in this order with stirring, and the mixture was stirred at room temperature for 30 minutes, thereby obtaining a coating liquid (CT-7) having a solid content concentration of 2.6%.

[0332] [Example 1]

[0333] Example 1-1

[0334] As the substrate (X), PET12 (substrate (X-1)) was prepared. The coating liquid (S-1) was applied to this substrate using a bar coater so as to have an average thickness after drying of 0.3 μm. The film after application was dried at 120°C for 3 minutes, and then heat-treated at 180°C for 1 minute, thereby forming a precursor layer of layer (Y-1) on the substrate. Next, the coating liquid (T-1) was applied using a bar coater so as to have an average thickness after drying of 0.2 μm, and then dried at 120°C for 3 minutes, and then heat-treated at 210°C for 1 minute. In this way, a multilayer structure (1-1-1) having the structure of substrate (X-1) / layer (Y-1) / layer (Z-1) was obtained. For the obtained multilayer structure (1-1-1), the average thickness of layer (Y) and layer (Z), the calculation of molar ratio M MR / M Al , and the calculation of molar ratio M MR / M C were measured according to the methods described in the above evaluation methods (1), (6), and (7). The results are shown in Table 1. Further, for the obtained multilayer structure (1-1-1), the infrared absorption spectrum was measured according to the method described in the above evaluation method (8), and the result was that the maximum absorption wave number in the region of 800 to 1400 cm -1 . -1

[0335] ​On the obtained multilayer structure (1-1-1), an adhesive layer was formed, and ONY 15 was laminated on the adhesive layer, thereby obtaining a laminate. Subsequently, an adhesive layer was formed on the ONY 15 of the laminate, and then CPP 50 was laminated on the adhesive layer, and left to stand for 3 days at 40°C, and aging was performed. In this way, a multilayer structure (1-1-2) having a structure of substrate (X-1) / layer (Y-1) / layer (Z-1) / adhesive layer / ONY 15 / adhesive layer / CPP 50 was obtained. The two adhesive layers were each formed by applying a two-component adhesive using a bar coater so that the average thickness after drying was 3 μm, and drying it. The two-component adhesive was a two-component reaction-type polyurethane adhesive composed of "TAKE LAC" (registered trademark) "A-525S" (trade name) manufactured by Mitsui Chemicals, Inc., and "TAKE NET" (registered trademark) "A-50" (trade name) manufactured by Mitsui Chemicals, Inc.

[0336] For the multilayer structure (1-1-2), the oxygen permeability, the moisture permeability, the oxygen permeability and the moisture permeability after bending treatment, and the appearance evaluation after retort treatment were performed according to the methods described in the aforementioned evaluation methods (2) to (5). The results are shown in Table 1.

[0337] <Example 1-2 to 1-17, Comparative Example 1-1 to 1-10>

[0338] The multilayer structures (1-2-1) to (1-17-1), (C1-1-1) to (C1-10-1) and the multilayer structures (1-2-2) to (1-17-2), (C1-1-2) to (C1-10-2) were produced by the same method as in Example 1-1, except that the kind of the coating solution (T) and the average thickness of the layer (Z) were changed as described in Table 1, and evaluated. The results are shown in Table 1. Furthermore, for the obtained multilayer structures (1-2-1) to (1-17-1), (C1-1-1) to (C1-10-1), the infrared absorption spectrum was measured according to the method described in the aforementioned evaluation method (8), and the results were that the maximum absorption wave number in the region of 800 to 1400 cm -1 . -1

[0339] <Comparative Example 1-11>

[0340] As the substrate (X), PET 12 (substrate (X-1)) was prepared. On the substrate (X-1), an aluminum evaporation layer of 0.08 μm was formed using the PVD method with aluminum as the evaporation source, and an aluminum evaporation film was obtained. The layer (Z) was laminated on the obtained aluminum evaporation layer, and otherwise, the multilayer structures (C1-11-1) and (C1-11-2) were produced by the same method as in Example 1-1, and evaluated. The results are shown in Table 1. ​

[0341] <Comparative Example 1-12>

[0342] As the substrate (X), PET12 (substrate (X-1)) was prepared. On this substrate (X-1), an alumina evaporation layer of 0.04 μm was formed using the PVD method with alumina as the evaporation source, to obtain an alumina evaporation film. On the obtained alumina evaporation layer, layer (Z) was laminated, and otherwise, using the same method as in Example 1-1, multilayer structures (C1-12-1) and (C1-12-2) were produced, and evaluated. The results are shown in Table 1.

[0343] [Table 1]

[0344]

[0345] [Example 2] Flat soft pouch

[0346] <Example 2-1>

[0347] The multilayer structure (1-1-2) produced in Example 1-1 was cut into 120 mm x 120 mm, and two pieces of the multilayer structure were overlapped with the CPP layer on the inside, and the three sides of the rectangle were heat-sealed, to form a flat soft pouch (2-1-1). In this flat soft pouch, 100 mL of water was filled. For the obtained flat soft pouch, retort treatment (hot water heat storage type) was performed under the same conditions as in Example 1-1, and as a result, no pouch breakage or interlayer peeling occurred, and the appearance was good.

[0348] [Example 3] Infusion bag

[0349] <Example 3-1>

[0350] From the multilayer structure (1-1-2) produced in Example 1-1, two pieces of 120 mm x 100 mm were cut out. Next, the two cut pieces of the multilayer structure were overlapped with the CPP layer on the inside, and the periphery was heat-sealed, and a polypropylene suction nozzle (mouth plug member) was installed by heat-sealing, to produce an infusion bag (3-1-1). In the infusion bag (3-1-1), 100 mL of water was filled, and retort treatment (hot water heat storage type) was performed under the same conditions as in Example 1-1, and as a result, no pouch breakage or interlayer peeling occurred, and the appearance was good.

[0351] [Example 4] Cap material for container

[0352] <Example 4-1>

[0353] A circular multilayer structure body having a diameter of 100 mm was cut out from the multilayer structure body (1-1-2) produced in Example 1-1, as a lid material for a container. Further, as a container main body, a flange-equipped container ("HY-RET FLEX" (registered trademark), "HR78-84" (trade name) manufactured by Toyo Kanetsu Industries Co., Ltd.) was prepared. This container had a cup shape with a diameter of 78 mm and a height of 30 mm on the upper surface. The upper surface of the container was open, and the width of the flange portion formed on the periphery thereof was 6.5 mm. The container was composed of a 3-layer laminate of an olefin layer / steel layer / olefin layer. Subsequently, the container main body was filled with water to almost full, and the lid material was heat-sealed to the flange portion, whereby a container with a lid (4-1-1) was obtained. At this time, the CPP layer of the lid material was disposed so as to contact the flange portion, and the lid material was heat-sealed. The container with a lid (4-1-1) was subjected to retort treatment (hot water heat-retention type) under the same conditions as in Example 1-1, as a result of which no breakage of the container and interlayer peeling occurred, and a good appearance was maintained.

[0354] [Example 5] In-mold label container

[0355] Example 5-1

[0356] On two pieces of CPP100, a two-component adhesive was applied in a dried thickness of 3 μm each using a bar coater and dried. The two-component adhesive was a two-component reaction-type polyurethane adhesive formed of "TAKE LAC" (registered trademark) "A-525S" manufactured by Mitsui Chemicals, Inc. and "TAKE NET" (registered trademark) "A-50" manufactured by Mitsui Chemicals, Inc. Subsequently, the two pieces of CPP layer were laminated with the multilayer structure body (1-1-1) of Example 1-1, and cured by standing at 40°C for 3 days, to obtain a multilayer label (5-1-1) having a structure of CPP100 / adhesive layer / substrate (X-1) / layer (Y-1) / layer (Z-1) / adhesive layer / CPP100.

[0357] The multilayer label (5-1-1) was cut in a shape corresponding to the inner wall surface shape of the female portion of a container molding mold, and installed to the inner wall surface of the female portion. Subsequently, the male portion was pushed into the female portion. Subsequently, molten polypropylene ("NOVA TECH" (registered trademark) "EA7A" manufactured by Japan Polypro Co., Ltd.) was injected at 220°C into the cavity between the male portion and the female portion, and injection molding was performed, to mold a container (5-1-2) of interest. The thickness of the container main body was 700 μm, and the surface area was 83 cm 2 . The outer side of the container was entirely covered with the multilayer label (5-1-1), the joint overlapped with the multilayer label (5-1-1), and there was no portion on the outer side of the container which was not covered with the multilayer label (5-1-1). The container (5-1-2) had a good appearance.

[0358] [Example 6] Extrusion-coating lamination

[0359] Example 6-1

[0360] In Example 1-1, after forming the adhesive layer on the layer (Z-1) of the multilayer structure (1-1-1), polyethylene resin (density: 0.917 g / cm 3 , melt flow rate: 8 g / 10 min) was extrusion-coated on the adhesive layer at a thickness of 20 μm at 295°C to obtain a laminate (6-1-1) having the structure of substrate (X-1) / layer (Y-1) / layer (Z-1) / adhesive layer / polyethylene. The adhesive layer was formed by applying a two-component adhesive using a bar coater at a dried thickness of 0.3 μm and drying it. The two-component adhesive was a two-component reaction-type polyurethane two-component reaction-type polyurethane adhesive formed of "TAKELAC" (registered trademark) "A-3210" manufactured by Mitsui Chemicals, Inc. and "TAKENATE" (registered trademark) "A-3070" manufactured by Mitsui Chemicals, Inc. The laminate (6-1-1) was subjected to the retort treatment (hot water storage type) under the same conditions as in Example 1-1, and as a result, no interlayer peeling occurred and a good appearance was maintained.

[0361] [Example 7] Effect of filling material

[0362] Example 7-1

[0363] The flat soft pouch (2-1-1) produced in Example 2-1 was filled with 500 mL of 1.5% ethanol aqueous solution, and subjected to a retort treatment in hot water at 120°C and 2.5 atm for 30 minutes using a retort treatment device (Flavor Ease RCS-60, manufactured by Nikka Precision Industries, Ltd.), and as a result, no interlayer peeling occurred and a good appearance was maintained.

[0364] Examples 7-2 to 7-9

[0365] A retort treatment was performed in the same manner as in Example 7-1, except that 500 mL of another filling material was used instead of 500 mL of 1.5% ethanol aqueous solution and filled into the flat soft pouch (2-1-1). Further, a sample for measurement was cut out from the flat soft pouch after the retort treatment, and the oxygen permeability of the sample was measured. As the other filling materials, 1.0% ethanol aqueous solution (Example 7-2), vinegar (Example 7-3), citric acid aqueous solution at pH 2 (Example 7-4), cooking oil (Example 7-5), ketchup (Example 7-6), soy sauce (Example 7-7), and ginger paste (Example 7-8) were used. In any case, the oxygen permeability of the sample after the retort treatment was 0.2 mL / (m 2・atm). Further, the lid container (4-1-1) prepared in Example 4-1 was filled with orange juice to approximately the full, and was subjected to retort treatment in the same manner as in Example 7-1 (Example 7-9). After the retort treatment, no interlayer peeling occurred, and a good appearance was maintained.

[0366] From Examples 7-1 to 7-9, it was confirmed that the packaging material of the present application maintained a good appearance even after retort treatment in a state filled with various foods.

[0367] [Example 8] Vacuum Insulation Body

[0368] Example 8-1

[0369] The two-component adhesive used in Example 5-1 was applied to the CPP 50 in a manner such that the dried thickness was 3 μm, and was dried, thereby forming an adhesive layer. By adhering this CPP 50 to the PET layer of the multilayer structure (1-1-1) prepared in Example 1-1, a laminate (8-1-1) was obtained. Next, the aforementioned two-component reaction-type polyurethane adhesive was applied to the ONY 15 in a manner such that the dried thickness was 3 μm, and was dried, thereby forming an adhesive layer. Furthermore, by adhering this ONY 15 to the laminate (8-1-1), a multilayer structure (8-1-2) having the structure of CPP 50 / adhesive layer / substrate (X) / layer (Y) / layer (Z) / adhesive layer / ONY 15 was obtained.

[0370] The multilayer structure (8-1-2) was cut, and two pieces of laminate having a size of 700 mm x 300 mm were obtained. These two pieces of laminate were overlapped in a manner such that the CPP layers became the inner surfaces of each other, and the three sides were heat-sealed at a width of 10 mm, thereby preparing a three-side bag. Next, an insulating core material was filled from the opening of the three-side bag, and the three-side bag was sealed using a vacuum packaging machine under conditions of 20°C and an internal pressure of 10 Pa, thereby obtaining a vacuum insulation body (8-1-3). The insulating core material used was silica powder. After the vacuum insulation body (8-1-3) was left to stand for 360 days under conditions of 40°C and 15% RH, the internal pressure of the vacuum insulation body was measured using a Pirani vacuum gauge, and the result was 37.0 Pa.

[0371] Example 8-2

[0372] The two-component adhesive used in Example 5-1 was applied to the layer (Z) of the multilayer structure (1-1-1) in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. By laminating this multilayer structure (1-1-1) and ONY 15, a laminate (8-2-1) was obtained. Next, the aforementioned two-component reaction-type polyurethane adhesive was applied to the ONY 15 of the laminate (8-2-1) in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. Also, by laminating this laminate (8-2-1) and the aluminum vapor deposition surface of VM-XL, a laminate (8-2-2) was obtained. Further, the aforementioned two-component reaction-type polyurethane adhesive was applied to the LLDPE 50 in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. Also, by laminating this LLDPE 50 and the VM-XL surface of the laminate (8-2-2), a multilayer structure (8-2-3) having the structure of substrate (X) / layer (Y) / layer (Z) / adhesive layer / ONY 15 / adhesive layer / VM-XL / adhesive layer / LLDPE 50 was obtained.

[0373] The multilayer structure (8-2-3) was cut, and two pieces of laminate having a size of 200 mm x 200 mm were obtained. These two pieces of laminate were overlapped in a manner such that the LLDPE 50 became the inner surface of each other, and the three sides were heat-sealed at a width of 10 mm, thereby producing a three-side bag. Next, the heat-insulating core material was filled from the opening of the three-side bag, and the three-side bag was sealed using a vacuum packaging machine under the conditions of 20°C and an internal pressure of 10 Pa, thereby obtaining a vacuum heat insulator (8-2-4). The heat-insulating core material used was glass fiber. The thermal conductivity was measured using a thermal conductivity measuring device before and after the vacuum heat insulator (8-2-4) was left to stand under the conditions of 70°C and 90% RH for 2 weeks, and the difference in thermal conductivity before and after the standing was 4.4 mW / mK.

[0374] Example 8-3

[0375] The two-component adhesive used in Example 5-1 was applied to the layer (Z) of the multilayer structure (1-1-1) in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. By laminating this multilayer structure (1-1-1) and the substrate (X) side of the laminate (8-2-1), a laminate (8-3-1) was obtained.

[0376] Next, the aforementioned two-component reaction type polyurethane-based adhesive was applied to the ONY 15 of the laminate (8-3-1) in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. Further, by adhering the laminate (8-3-1) and the aluminum vapor deposition surface of the VM-XL, a laminate (8-3-2) was obtained. Further, the aforementioned two-component reaction type polyurethane-based adhesive was applied to the LLDPE 50 in a manner such that the dried thickness reached 3 μm, and was dried, thereby forming an adhesive layer. Further, by adhering the LLDPE 50 and the VM-XL surface of the laminate (8-3-2), a multilayer structure (8-3-3) having a structure of substrate (X) / layer (Y) / layer (Z) / adhesive layer / substrate (X) / layer (Y) / layer (Z) / adhesive layer / VM-XL / adhesive layer / LLDPE 50 was obtained.

[0377] The multilayer structure (8-3-3) was cut, and two pieces of laminate having a size of 200 mm x 200 mm were obtained. The two pieces of laminate were overlapped in a manner such that the LLDPE 50 became the inner surface of each other, and the three sides were heat-sealed in a width of 10 mm, thereby producing a three-side bag. Next, a heat-insulating core material was filled in the opening of the three-side bag, and the three-side bag was sealed using a vacuum packaging machine under conditions of 20°C and an internal pressure of 10 Pa, thereby obtaining a vacuum heat insulator (8-3-4). The heat-insulating core material was glass fiber. The thermal conductivity was measured using a thermal conductivity measuring device before and after the vacuum heat insulator (8-3-4) was left to stand for 2 weeks under conditions of 70°C and 90% RH, and the difference in thermal conductivity before and after the standing was 3.6 mW / mK.

[0378] [Example 9] Protective sheet

[0379] Example 9-1

[0380] An adhesive layer was formed on the multilayer structure (1-1-1) produced in Example 1-1, and an acrylic resin film (thickness: 50 μm) was laminated on the adhesive layer, thereby obtaining a laminate. Next, after an adhesive layer was formed on the laminate of the multilayer structure (1-1-1), PET 50 was laminated, thereby obtaining a protective sheet (9-1-1) having a structure of PET / adhesive layer / substrate (X-1) / layer (Y-1) / layer (Z-1) / adhesive layer / acrylic resin film. The aforementioned two adhesive layers were each formed by applying a two-component adhesive in a manner such that the dried thickness reached 3 μm, and drying. As the two-component adhesive, a two-component reaction type polyurethane-based adhesive composed of "Takelac" (registered trademark) "A-1102" manufactured by Mitsui Chemicals, Inc. and "Takeneet" (registered trademark) "A-3070" manufactured by Mitsui Chemicals, Inc. was used.

[0381] Next, as a durability test of the resulting protective sheet (9-1-1), a test of storing the protective sheet at 85°C, 85% RH under an atmosphere at atmospheric pressure for 1000 hours (a damp heat test) was performed using a constant temperature and humidity test machine, and as a result, the protective sheet (9-1-1) did not undergo interlayer peeling and maintained a good appearance.

Claims

1. A multilayer structure comprising a substrate X, a layer Y, and a layer Z, at least one set of the layer Y and the layer Z being stacked adjacent to each other, the layer Y containing a reaction product D of a metal oxide A and an inorganic phosphorus compound BI, the metal oxide A containing aluminum atoms, the layer Z containing a metal compound R having metal atoms M R and a hydroxyl group-containing resin W, the number of moles of the metal atoms M R per unit area of the layer Y and the layer Z, the molar ratio of the number of moles of the metal atoms M MR to the number of moles of the aluminum atoms M Al being represented by M MR / M Al is 0.0005 or more and 0.05 or less, the metal atoms M R comprise at least one selected from silicon, titanium, and zirconium, the hydroxyl group-containing resin W is a vinyl alcohol-based resin, the mass ratio of the hydroxyl group-containing resin W to the metal compound R in the layer Z, represented by W / R, is 2.0 or more and 90 or less, and the aforementioned metal compound R is at least one selected from 3-glycidoxypropyltrimethoxysilane and titanium lactate.

2. The multilayer structure of claim 1, wherein, The resin W containing a hydroxyl group has at least carbon atoms, and the metal atoms M per unit area of the layer Z R The number of moles M of the metal atoms M MR The molar ratio with respect to the number of moles Mc of the carbon atoms is expressed as M MR / M C is 0.0007 or more and 0.07 or less.

3. The multilayer structure of claim 1, wherein, The hydroxyl group-containing resin W is polyvinyl alcohol.

4. The multilayer structure according to claim 1, having a laminated structure in which a substrate X, a layer Y, and a layer Z are laminated in this order.

5. The multilayer structure of claim 1, wherein, The average thickness of the layer Z is 50 nm or more.

6. The multilayer structure of claim 1, wherein, The ratio of the average thickness of the layer Z to the average thickness of the layer Y, expressed as layer Z / layer Y, is 0.10 or more.

7. The method for producing a multilayer structure according to any one of claims 1 to 6, wherein comprising: Process I: on the substrate X, a coating liquid S containing a metal oxide A containing aluminum atoms, an inorganic phosphorus compound BI, and a solvent is applied, and by removing the solvent, a precursor layer of the layer Y is formed, Process II: on the aforementioned layer Y precursor layer, a coating liquid T containing a resin W, the aforementioned metal compound R, and a solvent is applied, and by removing the solvent, a precursor layer of the layer Z is formed, and Process III: the aforementioned layer Y precursor layer and the aforementioned layer Z precursor layer are heat-treated, and the layer Y and the layer Z are formed.

8. A packaging material comprising the multilayer structure according to any one of claims 1 to 6.

9. The packaging material according to claim 8, which is a stand-up pouch, a vacuum packaging bag, a soft packaging bag, a laminated tube container, an infusion bag, a paper container, a tape, a lid material for a container, or an in-mold label container.

10. Vacuum insulating body, wherein The packaging material according to claim 9 is a vacuum packaging bag, the aforementioned vacuum packaging bag contains a content, the aforementioned content is a core material, and the inside of the aforementioned vacuum packaging bag is reduced in pressure.

11. A protective sheet for electronic devices comprising the multilayer structure according to any one of claims 1 to 6.

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