Laminated container for boiling sterilization and method for manufacturing the same

Abstract

To provide a laminated container for boiling sterilization having excellent resistance to boiling sterilization, and a method for manufacturing the same.SOLUTION: There is provided a laminated container for boiling sterilization which comprises a laminated film 1. The laminated film 1 comprises a first base layer 2, a first adhesive layer 3, and a metallized film 4. The metallized film 4 comprises a resin film 7 and a metallized layer 8. The first adhesive layer 3 and the metallized layer 8 are arranged so as to contact each other. The first adhesive layer 3 contains a cured product of a bi-components curing polyurethane adhesive. The bi-components curing polyurethane adhesive contains a polyol component and a polyisocyanate component. The polyol component contains polyester polyol. The polyisocyanate component contains an isocyanurate derivative of HDI. A tensile storage modulus of the cured bi-components curing polyurethane adhesive at 100°C is 20×105 to 100×105 Pa.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminated container for boiling sterilization and a method for producing the same. [Background technology]

[0002] Gas barrier composite films have been known as packaging materials. A gas barrier composite film includes, for example, a plastic substrate, a metal-deposited film, and an adhesive layer that bonds them together. For example, the following laminated barrier films have been proposed as gas barrier composite films.

[0003] The laminated barrier film comprises multiple barrier films. The multiple barrier films are laminated via an adhesive layer. More specifically, each barrier film comprises a polyethylene terephthalate (PET) film, an organic film obtained by radical polymerization, and an inorganic film obtained by metal sputtering. The surface of one barrier film opposite the inorganic film side (PET film surface) is laminated to the inorganic film side surface of another barrier film (inorganic film surface) via a urethane adhesive. Furthermore, an ethylene-tetrafluoroethylene copolymer (ETFE) film is laminated to the inorganic film side surface of the barrier film via an acrylic adhesive. This results in a laminated barrier film (see, for example, Patent Document 1 (Example 3)). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-223784 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in the field of packaging materials, laminated barrier films are subjected to boiling sterilization (low-temperature heat sterilization) depending on the application. In boiling sterilization, for example, a container (pouch) is formed from the laminated barrier film, the contents are sealed in the container, and the container is heated to 90 to 100°C (low-temperature heating).

[0006] However, in the above laminated barrier film, the inorganic film and the urethane adhesive are in contact with each other.

[0007] In this case, the laminated barrier film may not have sufficient resistance to boiling sterilization. Specifically, when the laminated barrier film is boiled, defects (deposition defects) may occur in the inorganic film depending on the composition of the urethane adhesive.

[0008] The present invention relates to a laminated container for boiling sterilization that has excellent resistance to boiling sterilization, and a method for producing the same. [Means for solving the problem]

[0009] The present invention [1] is a laminated container for boiling sterilization comprising a laminate, the laminate comprising a base layer, a polyurethane adhesive layer disposed on at least one side of the base layer, and a metallized film disposed on at least one side of the polyurethane adhesive layer, the metallized film comprising a resin film and a metallized layer vapor-deposited on the resin film, the polyurethane adhesive layer and the metallized layer being disposed so as to be in contact with each other, the polyurethane adhesive layer containing a cured product of a two-component curing polyurethane adhesive, the two-component curing polyurethane adhesive containing a polyol component and a polyisocyanate component, the polyol component containing a polyester polyol, and the polyisocyanate component containing an isocyanurate derivative of hexamethylene diisocyanate, the cured product of the two-component curing polyurethane adhesive having a tensile storage modulus (E') at 100°C of 20 × 10 5 ~100×10 5 The laminated container for boiling sterilization is Pa.

[0010] The present invention [2] includes the laminated container for boil sterilization described in [1] above, in which the content of the isocyanurate derivative of the hexamethylene diisocyanate is 90 mass% or more relative to the total solid content of the polyisocyanate component.

[0011] The present invention [3] includes the laminated container for boiling sterilization according to the above [1] or [2], wherein the aromatic ring concentration of the polyester polyol is 3.2 to 3.6 mmol / g.

[0012] The present invention [4] includes the laminated container for boiling sterilization according to any one of the above [1] to [3], wherein the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is 1.5 to 5.0.

[0013] The present invention [5] comprises a preparation step of preparing a two-component curing polyurethane adhesive, a substrate layer, and a metal vapor-deposited film, and an adhesion step of adhering the substrate layer and the metal vapor-deposited film with the two-component curing polyurethane adhesive, wherein the two-component curing polyurethane adhesive contains a polyol component and a polyisocyanate component, and the metal vapor-deposited film comprises a resin film and a metal vapor-deposited layer deposited on the resin film, and in the adhesion step, a polyurethane adhesive layer is formed by curing the two-component curing polyurethane adhesive, and the polyurethane adhesive layer and the metal vapor-deposited layer are arranged so as to be in contact with each other, the polyol component contains a polyester polyol, and the polyisocyanate component contains an isocyanurate derivative of hexamethylene diisocyanate, and the tensile storage modulus (E') at 100°C of the cured product of the two-component curing polyurethane adhesive is 20 × 10 5 Pa~100×10 5 The present invention includes a method for manufacturing a laminated container for boiling sterilization, which is Pa.

[0014] The present invention [6] includes the method for producing a laminated container for boil sterilization described in [5] above, in which the content of the isocyanurate derivative of the hexamethylene diisocyanate is 90 mass% or more relative to the total solid content of the polyisocyanate component.

[0015] The present invention [7] includes the method for producing a laminated container for boiling sterilization according to the above [5] or [6], wherein the aromatic ring concentration of the polyester polyol is 3.2 to 3.6 mmol / g.

[0016] The present invention [8] includes the method for producing a laminated container for boil sterilization according to any one of the above [5] to [7], wherein the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is 1.5 to 5.0. [Effects of the Invention]

[0017] In the laminated container for boiling sterilization and the method for producing the same of the present invention, the polyurethane adhesive layer is formed from a two-component curing polyurethane adhesive and is in contact with the metal vapor deposition layer.

[0018] In the two-component curing polyurethane adhesive, the polyol component contains a polyester polyol, and the polyisocyanate component contains an isocyanurate derivative of hexamethylene diisocyanate. The cured product of the two-component curing polyurethane adhesive has a tensile storage modulus (E') at 100°C within a specified range. Therefore, the laminated container for boiling sterilization has excellent boiling sterilization resistance. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram showing a laminated body in one embodiment of a laminated container for boiling sterilization of the present invention. [Figure 2]Figure 2A shows a process for preparing a first substrate layer, Figure 2B shows a process for forming an uncured adhesive layer on one side of the first substrate layer, Figure 2C shows a process for bonding the first substrate layer and a metallized film via a two-component curing polyurethane adhesive, Figure 2D shows a process for forming a coating of two-component curing polyurethane adhesive on the metallized film, Figure 2E shows a process for bonding the metallized film and a second substrate layer via a two-component curing polyurethane adhesive, and Figure 2F shows a process for curing the two-component curing polyurethane adhesive. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1. Laminated container for boiling sterilization (1) Overall structure of the laminated container for boiling sterilization The laminated container for boiling sterilization is a container that is subjected to boiling sterilization (low-temperature heat sterilization). The laminated container for boiling sterilization is provided with a laminated film 1 (see FIG. 1) as a laminate. More specifically, the laminated container for boiling sterilization is formed by processing the laminated film 1 into a container shape by a known method.

[0021] As shown in Figure 1, the laminate film 1 comprises a first substrate layer 2 as a base material layer, a first adhesive layer 3 as a polyurethane adhesive layer arranged on at least one side of the first substrate layer 2, and a metal vapor deposition film 4 arranged on at least one side of the first adhesive layer 3.

[0022] Furthermore, the laminate film 1 may include a second adhesive layer 5 in addition to the first adhesive layer 3, as needed. Furthermore, the laminate film 1 may include a second base material layer 6 in addition to the first base material layer 2, as needed.

[0023] 1, laminate film 1 includes, in order in the thickness direction, a first base material layer 2, a first adhesive layer 3, a metallized film 4, a second adhesive layer 5, and a second base material layer 6. Preferably, laminate film 1 is composed of first base material layer 2, first adhesive layer 3, metallized film 4, second adhesive layer 5, and second base material layer 6. Each layer will be described in detail below.

[0024] (2) First base layer The first base layer 2 may be, for example, a base material made of resin (resin base material). Examples of resins include thermoplastic resins and thermosetting resins, preferably thermoplastic resins. Examples of thermoplastic resins include polyolefin resins, polyester resins, polyamide resins, vinyl resins, acrylic resins, polycarbonate resins, and cellulose resins, preferably polyamide resins. Examples of polyamide resins include Nylon 6 (registered trademark), Nylon 66 (registered trademark), and polymetaxylylene adipamide, preferably Nylon 6 (registered trademark) and Nylon 66 (registered trademark). These may be used alone or in combination of two or more types.

[0025] The first substrate layer 2 may be a single-layer substrate or a multi-layer substrate. The first substrate layer 2 may be a non-stretched substrate, a uniaxially stretched substrate, or a biaxially stretched substrate. The first substrate layer 2 may be surface-treated. Examples of surface treatments include corona discharge treatment.

[0026] The first base layer 2 is formed by processing a resin by a known method. The shape of the first base layer 2 is not particularly limited.

[0027] The thickness of the first base layer 2 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the first base layer 2 is, for example, 1 to 200 μm, preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0028] (3) First adhesive layer The first adhesive layer 3 is an adhesive layer that bonds the first base material layer 2 and the metallized film 4. The first adhesive layer 3 (polyurethane adhesive layer) contains a cured product of a two-component curing polyurethane adhesive (described later).

[0029] Preferably, the first adhesive layer 3 is made of a cured product of a two-component curing polyurethane adhesive (described later). Details of the two-component curing polyurethane adhesive will be described later.

[0030] The first adhesive layer 3 is disposed so as to be in contact with at least one surface (upper side of the paper in FIG. 1) of the first base material layer 2. The first base material layer 2 is disposed so as to be in contact with the other surface (lower side of the paper in FIG. 1) of the metallized film 4.

[0031] The thickness of the first adhesive layer 3 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the first adhesive layer 3 is, for example, 1 to 200 μm, preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0032] (4) Metallized film The metallized film 4 includes a resin film 7 and a metallized layer 8 deposited on the resin film 7.

[0033] The resin film 7 is, for example, a film made of a resin. Examples of the resin include the resins described above as the first base layer 2. More specifically, examples of the resin include thermoplastic resins and thermosetting resins, and preferably thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, vinyl resins, acrylic resins, polycarbonate resins, and cellulose resins. Examples of the thermoplastic resin include polyester resins. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and preferably polyethylene terephthalate (PET). These can be used alone or in combination of two or more types.

[0034] The resin film 7 may be a single-layer film or a multi-layer film. The resin film 7 may be a non-stretched film, a uniaxially stretched film, or a biaxially stretched film. The resin film 7 may be surface-treated. Examples of surface treatments include corona discharge treatment and anchor coating treatment. An anchor coating layer is formed in the anchor coating treatment. Examples of the anchor coating layer include organic and inorganic films.

[0035] The thickness of the resin film 7 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the resin film 7 is, for example, 1 to 200 μm, or preferably 5 to 100 μm.

[0036] The metal vapor deposition layer 8 is laminated and disposed on the resin film 7. More specifically, the metal vapor deposition layer 8 is formed and disposed by, for example, vapor-depositing a metal on one or both surfaces of the resin film 7. In FIG. 1, the metal vapor deposition layer 8 is vapor-deposited only on the surface on the other side of the resin film 7 (the lower side of the paper in FIG. 1).

[0037] Examples of metals include magnesium, calcium, barium, titanium, zirconium, aluminum, indium, silicon, germanium, and tin. Examples of metals include metal oxides. Examples of metal oxides include aluminum oxide, magnesium oxide, titanium oxide, aluminum oxide, indium oxide, silicon oxide, silicon oxynitride, cerium oxide, calcium oxide, and tin oxide. Preferred examples of metals include aluminum, silicon, aluminum oxide, and silicon oxide. These can be used alone or in combination.

[0038] The method for forming the metal vapor deposition layer 8 is not particularly limited, and examples thereof include vacuum processes. Examples of vacuum processes include vacuum deposition, sputtering, ion plating, and chemical vapor deposition (CVD). These can be used alone or in combination of two or more.

[0039] The thickness of the metal vapor deposition layer 8 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the metal vapor deposition layer 8 is, for example, 1 to 500 nm, preferably 5 to 200 nm, and more preferably 10 to 100 nm.

[0040] The metallized film 4 is disposed so as to be in contact with at least one surface (the upper side of the paper in FIG. 1) of the first adhesive layer 3. More specifically, the metallized film 4 is disposed so that the metallized layer 8 of the metallized film 4 is in contact with the first adhesive layer 3. In other words, the first adhesive layer 3 (polyurethane adhesive layer) and the metallized layer 8 are in contact with each other.

[0041] The metallized film 4 is disposed so as to be in contact with the other surface (the lower surface of the paper in FIG. 1) of the second adhesive layer 5. More specifically, the resin film 7 of the metallized film 4 is disposed so as to be in contact with the second adhesive layer 5.

[0042] The thickness of the metallized film 4 is the sum of the thickness of the resin film 7 and the thickness of the metallized layer 8. The thickness of the metallized film 4 is in the range of, for example, 1 to 200 μm, or preferably 5 to 100 μm.

[0043] (5)Second adhesive layer The second adhesive layer 5 is an adhesive layer that bonds the metallized film 4 and the second base material layer 6. The second adhesive layer 5 contains, but is not particularly limited to, a cured product of a polyurethane adhesive. Preferably, the second adhesive layer 5 is made of a cured product of a polyurethane adhesive. The polyurethane adhesive may be a known polyurethane adhesive. Alternatively, the polyurethane adhesive may be the same type of polyurethane adhesive as the polyurethane adhesive (the two-component curing polyurethane adhesive described below) that forms the first adhesive layer 3.

[0044] Preferably, the second adhesive layer 5 is made of a cured product of the same type of polyurethane adhesive (a two-component curing polyurethane adhesive described below) as the polyurethane adhesive that forms the first adhesive layer 3. Details of the two-component curing polyurethane adhesive will be described later.

[0045] The second adhesive layer 5 is disposed so as to be in contact with at least one surface (upper side of the paper in FIG. 1) of the metallized film 4 (resin film 7), and the second adhesive layer 5 is disposed so as to be in contact with the other surface (lower side of the paper in FIG. 1) of the second base material layer 6.

[0046] The thickness of the second adhesive layer 5 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the second adhesive layer 5 is, for example, 1 to 200 μm, preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0047] (6) Second base layer The second base layer 6 may be, for example, a base material made of resin (resin base material). Examples of resin base materials include the above-mentioned thermoplastic resins and thermosetting resins, preferably the above-mentioned thermoplastic resins, and more preferably the above-mentioned polyolefin resins. Examples of polyolefin resins include polyethylene, polypropylene, and propylene-ethylene copolymers, preferably polyethylene. These may be used alone or in combination of two or more types.

[0048] The second substrate layer 6 may be a single-layer substrate or a multi-layer substrate. The second substrate layer 6 may be a non-stretched substrate, a uniaxially stretched substrate, or a biaxially stretched substrate. The second substrate layer 6 may be surface-treated. Examples of surface treatments include corona discharge treatment.

[0049] The second base layer 6 is formed by processing a resin by a known method. The shape of the second base layer 6 is not particularly limited.

[0050] The thickness of the second base layer 6 is not particularly limited and may be appropriately set depending on the purpose and application. From the viewpoint of boiling sterilization resistance, the thickness of the second base layer 6 is, for example, 1 to 200 μm, preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0051] (7) Laminate film (laminate) As will be described in detail later, the laminate film 1 is formed by sequentially laminating a first base material layer 2, a first adhesive layer 3, a metal vapor deposition film 4, a second adhesive layer 5, and a second base material layer 6.

[0052] The thickness of the laminate film 1 is, for example, the sum of the thickness of the first base material layer 2, the thickness of the first adhesive layer 3, the thickness of the metal-deposited film 4, the thickness of the second adhesive layer 5, and the thickness of the second base material layer 6. The thickness (total thickness) of the laminate film 1 is, for example, 3 to 500 μm, or preferably 5 to 200 μm.

[0053] 2. Two-component curing polyurethane adhesive (1) Overall structure of two-component curing polyurethane adhesive The two-component curing polyurethane adhesive contains a polyol component (base component) and a polyisocyanate component (curing agent). The two-component curing polyurethane adhesive preferably consists of a polyol component (base component) and a polyisocyanate component (curing agent).

[0054] More specifically, the two-component curing polyurethane adhesive comprises a polyol component (base component) and a polyisocyanate component (curing agent) that are mixed together at the time of use. The polyol component (base component) and the polyisocyanate component (curing agent) are described in detail below.

[0055] (2) Polyol component The polyol component contains a high-molecular-weight polyol as an essential component. The high-molecular-weight polyol is an organic compound (polymer) having two or more hydroxyl groups in the molecule and having a relatively high molecular weight. The number-average molecular weight of the high-molecular-weight polyol is, for example, 400 or more, for example, 20,000 or less. The number-average molecular weight can be determined as a polystyrene-equivalent molecular weight by a known gel permeation chromatography method (the same applies hereinafter).

[0056] The high-molecular-weight polyol contains a polyester polyol as an essential component, in other words, the polyol component (main component) contains a polyester polyol as an essential component.

[0057] Examples of polyester polyols include condensation polyester polyols and ring-opening polyester polyols. Examples of condensation polyester polyols include condensates of low-molecular-weight polyols and polybasic acids. Examples of ring-opening polyester polyols include ring-opening polymers of lactones and / or lactides. Examples of polyester polyols include preferably condensation polyester polyols. That is, the polyester polyol preferably contains a condensate of low-molecular-weight polyols and polybasic acids.

[0058] Low-molecular-weight polyols are organic compounds having two or more hydroxyl groups in the molecule and a relatively low molecular weight. The molecular weight of low-molecular-weight polyols is, for example, 40 or more and less than 400, preferably 300 or less. Examples of low-molecular-weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, dipropylene glycol, and bisphenol A. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. These can be used alone or in combination.

[0059] The low molecular weight polyol is preferably a dihydric alcohol. The dihydric alcohol is preferably a branched chain dihydric alcohol. Among the dihydric alcohols, examples of branched chain dihydric alcohols include neopentyl glycol and 3-methyl-1,5-pentanediol. As the low molecular weight polyol, neopentyl glycol is particularly preferred from the viewpoints of stain resistance, water resistance, and moist heat resistance.

[0060] Examples of polybasic acids include saturated aliphatic dicarboxylic acids, unsaturated aliphatic dicarboxylic acids, aromatic dicarboxylic acids, alicyclic dicarboxylic acids, other carboxylic acids, acid anhydrides, and acid halides. Examples of saturated aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, and sebacic acid. Examples of unsaturated aliphatic dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of aromatic dicarboxylic acids include orthophthalic acid, isophthalic acid, terephthalic acid, toluenedicarboxylic acid, and naphthalenedicarboxylic acid. Examples of alicyclic dicarboxylic acids include hexahydrophthalic acid. Examples of other carboxylic acids include dimer acid, hydrogenated dimer acid, and HET acid. Examples of acid anhydrides include oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, alkylsuccinic anhydride, tetrahydrophthalic anhydride, and trimellitic anhydride. Examples of acid halides include oxalic acid dichloride, adipic acid dichloride, and sebacic acid dichloride. These can be used alone or in combination of two or more.

[0061] The method for condensing a low-molecular-weight polyol with a polybasic acid is not particularly limited. For example, a low-molecular-weight polyol and a polybasic acid are subjected to ester condensation in an appropriate ratio. In the ester condensation, a known esterification catalyst can be used as needed. This produces a condensation polyester polyol. Alternatively, the condensation polyester polyol can be produced by, for example, transesterification of the alkyl ester of the polybasic acid described above with the low-molecular-weight polyol described above.

[0062] In terms of adhesive strength and boiling sterilization resistance, the number average molecular weight of the polyester polyol is, for example, 400 to 10,000, preferably 500 to 8,500, or more preferably 1,000 to 7,000.

[0063] In terms of adhesive strength and boiling sterilization resistance, the polyester polyol has an average number of hydroxyl groups of, for example, 2 to 6, preferably 2 to 4, and more preferably 3 to 4.

[0064] From the viewpoint of adhesive strength and boiling sterilization resistance, the polyester polyol preferably contains an aromatic ring. Examples of the aromatic ring include aromatic rings contained in the raw materials of the polyester polyol.

[0065] That is, when the polyester polyol is a condensation polyester polyol, from the viewpoint of boiling sterilization resistance, preferably, at least one of the low-molecular-weight polyol and the polybasic acid contains an aromatic ring.

[0066] An example of a low molecular weight polyol containing an aromatic ring is bisphenol A. An example of a polybasic acid containing an aromatic ring is aromatic dicarboxylic acid, more specifically, orthophthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, and naphthalenedicarboxylic acid. These can be used alone or in combination of two or more. Preferably, an aromatic ring-containing polybasic acid is used, more preferably orthophthalic acid, isophthalic acid, and terephthalic acid.

[0067] The aromatic ring concentration of the polyester polyol is, for example, 0.0 to 10.0 mmol / g, preferably 1.0 to 5.0 mmol / g, more preferably 3.0 to 4.0 mmol / g, even more preferably 3.2 to 3.6 mmol / g, and particularly preferably 3.3 to 3.5 mmol / g. The aromatic ring concentration is the content (mmol) of aromatic rings relative to the total amount (g) of the polyester polyol, and is calculated from the raw materials and charging recipe of the polyester polyol.

[0068] The high molecular weight polyol can optionally contain other high molecular weight polyols. The other high molecular weight polyols are high molecular weight polyols other than polyester polyols. Examples of other high molecular weight polyols include polyether polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used alone or in combination of two or more. The high molecular weight polyol preferably does not contain other high molecular weight polyols. The polyol component can optionally contain the above-mentioned low molecular weight polyols. The polyol preferably does not contain low molecular weight polyols. The polyol component preferably consists of the above-mentioned polyester polyols.

[0069] (3) Polyisocyanate component (hardener) The polyisocyanate component contains, as an essential component, an isocyanurate derivative of hexamethylene diisocyanate.

[0070] Hexamethylene diisocyanate isocyanurate derivatives are isocyanurate derivatives obtained from hexamethylene diisocyanate (HDI). Isocyanurate derivatives contain symmetric and asymmetric isocyanurate groups. In addition, isocyanurate derivatives contain no allophanate groups or allow the inclusion of trace amounts of allophanate groups.

[0071] The isocyanurate derivative of hexamethylene diisocyanate can be produced by a known method, for example, by subjecting hexamethylene diisocyanate to an isocyanuration reaction in the presence of a known isocyanuration catalyst (trimerization catalyst).

[0072] The reaction conditions for the isocyanuration reaction are appropriately set. For example, the atmospheric conditions are an inert gas atmosphere and normal pressure (atmospheric pressure). The reaction temperature is, for example, 50 to 150°C. The reaction time is, for example, 5 to 120 minutes. By the isocyanuration reaction, symmetrical and asymmetrical isocyanurate groups are formed, and an isocyanurate derivative of hexamethylene diisocyanate is obtained.

[0073] In addition, symmetric and asymmetric isocyanurate groups are more easily formed by urethane reaction. Therefore, in the production of isocyanurate derivatives of hexamethylene diisocyanate, alcohol is added as needed to cause the urethane reaction.

[0074] More specifically, examples of methods for producing an isocyanurate derivative of hexamethylene diisocyanate include a method in which hexamethylene diisocyanate and an alcohol are first subjected to a urethane reaction, and then the reaction product is subjected to an isocyanuration reaction in the presence of an isocyanuration catalyst. Also, examples of methods for producing an isocyanurate derivative of hexamethylene diisocyanate include a method in which hexamethylene diisocyanate is first isocyanurated in the presence of an isocyanuration catalyst, and then the reaction product is subjected to a urethane reaction with an alcohol. A preferred method is a method in which hexamethylene diisocyanate and an alcohol are first subjected to a urethane reaction, and then the reaction product is subjected to an isocyanuration reaction in the presence of an isocyanuration catalyst.

[0075] Examples of alcohols include known monohydric and dihydric alcohols. The amount of alcohol to be added is appropriately determined depending on the purpose and application. For example, the amount of alcohol is 0.1 to 5 parts by mass, preferably 0.5 to 3 parts by mass, per 100 parts by mass of hexamethylene diisocyanate.

[0076] The reaction conditions for the urethanization reaction are set appropriately. For example, the atmospheric conditions are an inert gas atmosphere and a normal pressure (atmospheric pressure) atmosphere. The reaction temperature is, for example, 20 to 100°C. The reaction time is, for example, 30 to 600 minutes. A urethane-modified product of hexamethylene diisocyanate is obtained by the urethanization reaction.

[0077] Next, in this method, the urethane-modified hexamethylene diisocyanate is subjected to the above-mentioned isocyanuration reaction, thereby obtaining an isocyanurate derivative of hexamethylene diisocyanate (an isocyanurate derivative of a urethane-modified hexamethylene diisocyanate).

[0078] In such cases, the isocyanurate derivative of hexamethylene diisocyanate may inevitably contain a trace amount of allophanate groups. The content of allophanate groups is, for example, less than 10 moles, preferably 5 moles or less, per 100 moles of symmetrical or asymmetrical isocyanurate groups. The content of allophanate groups is 0 moles or more per 100 moles of symmetrical or asymmetrical isocyanurate groups.

[0079] The isocyanurate derivative of hexamethylene diisocyanate is purified as necessary to remove unreacted hexamethylene diisocyanate. Purification methods include, for example, distillation and extraction, and preferably distillation. Distillation methods include, for example, thin film distillation (Smith distillation).

[0080] From the viewpoints of adhesive strength and boiling sterilization resistance, the isocyanate group content of the isocyanurate derivative of hexamethylene diisocyanate is, for example, 18 to 30 mass%, or preferably 20 to 26 mass%. The isocyanate group content can be determined by the n-dibutylamine method in accordance with JIS K 1556 (2006) (the same applies hereinafter).

[0081] From the viewpoint of adhesive strength and boiling sterilization resistance, the isocyanate group equivalent of the isocyanurate derivative of hexamethylene diisocyanate is, for example, 150 to 1000, or preferably 200 to 700. The isocyanate group equivalent is synonymous with the amine equivalent, and can be determined by Method A or Method B of JIS K 1603-1 (2007) (the same applies hereinafter).

[0082] The polyisocyanate component (curing agent) may optionally contain other polyisocyanates, which are polyisocyanates other than isocyanurate derivatives of hexamethylene diisocyanate.

[0083] Other polyisocyanates include, for example, polyisocyanate monomers and polyisocyanate derivatives that are commonly used industrially. Examples of polyisocyanate monomers include linear aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates. Examples of linear aliphatic polyisocyanates include pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), hydrogenated diphenylmethane diisocyanate (HDI), and the like. 12Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI). Examples of araliphatic polyisocyanates include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). Examples of polyisocyanate derivatives include derivatives of the above polyisocyanate monomers. Examples of derivatives include polymers, isocyanurate derivatives (excluding isocyanurate derivatives of hexamethylene diisocyanate), allophanate derivatives, polyol derivatives, biuret derivatives, urea derivatives, oxadiazinetrione derivatives, and carbodiimide derivatives. These can be used alone or in combination of two or more.

[0084] From the viewpoint of adhesive strength and boiling sterilization resistance, the content of other polyisocyanates is, for example, 10 mass% or less, preferably 5 mass% or less, more preferably 2 mass% or less, even more preferably 1 mass% or less, and particularly preferably 0 mass% relative to the total solid content of the polyisocyanate component.

[0085] That is, from the viewpoint of adhesive strength and boiling sterilization resistance, the content of the isocyanurate derivative of hexamethylene diisocyanate relative to the total solid content of the polyisocyanate component is, for example, 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass. In other words, particularly preferably, the polyisocyanate component consists of an isocyanurate derivative of hexamethylene diisocyanate.

[0086] In terms of adhesive strength and boiling sterilization resistance, the isocyanate group content of the polyisocyanate component is, for example, 18 to 30 mass %, or preferably 20 to 26 mass %.

[0087] In terms of adhesive strength and boiling sterilization resistance, the polyisocyanate component has an isocyanate group equivalent of, for example, 150 to 1,000, or preferably 200 to 700.

[0088] In terms of adhesive strength and boiling sterilization resistance, the average number of functional groups of the polyisocyanate component is, for example, 2.5 to 4, or preferably 2.8 to 3.3.

[0089] (4) Other ingredients The two-component curing polyurethane adhesive may contain additives as other components. Examples of additives include urethane catalysts, antioxidants, UV absorbers, heat stabilizers, light stabilizers, crosslinkers, antistatic agents, silane coupling agents, coating property improvers, leveling agents, antifoaming agents, cure accelerators, cure retarders, plasticizers, surfactants, pigments, fillers, organic particles, inorganic particles, metal particles, antifungal agents, processing aids, and antioxidants. These may be used alone or in combination of two or more. The amount and timing of addition of the additives are not particularly limited and may be determined as appropriate.

[0090] The two-component curing polyurethane adhesive may contain a solvent as another component. Examples of solvents include ketones, nitriles, alkyl esters, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ethers, glycol ether esters, halogenated aliphatic hydrocarbons, and polar aprotic solvents. These may be used alone or in combination of two or more. The amount and timing of addition of the solvent are not particularly limited and may be set appropriately. From the viewpoint of processability, alkyl esters are preferred. Examples of alkyl esters include methyl acetate, ethyl acetate, and butyl acetate, with ethyl acetate being preferred.

[0091] (5) Cured product of two-component curing polyurethane adhesive As described below, the two-component curing polyurethane adhesive is used in the production of laminated containers for boiling sterilization. More specifically, the cured product of the two-component curing polyurethane adhesive bonds the first substrate layer 2 to the metal vapor deposition layer 8 of the metal vapor deposition film 4. Furthermore, if necessary, the cured product of the two-component curing polyurethane adhesive bonds the second substrate layer 6 to the resin film 7 of the metal vapor deposition film 4.

[0092] From the viewpoint of adhesive strength and boiling sterilization resistance, the cured product of the two-component curing polyurethane adhesive has a predetermined tensile storage modulus (E').

[0093] In other words, the formulation of the two-component curing polyurethane adhesive (type of polyisocyanate component, type of polyol component, and blending ratio) is selected so that the cured product of the two-component curing polyurethane adhesive has a predetermined tensile storage modulus (E').

[0094] More specifically, from the viewpoint of adhesive strength and boiling sterilization resistance, the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C is 20 × 10 5 Pa~100×10 5 Pa, preferably 25 x 10 5 Pa~80×10 5 Pa, more preferably 30 x 10 5 Pa~60×10 5 Pa, more preferably 40 x 10 5 Pa~50×10 5 The tensile storage modulus (E') is measured in Pa. The tensile storage modulus (E') is measured in accordance with the examples described later.

[0095] In addition, from the viewpoint of adhesive strength and boiling sterilization resistance, the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 60°C is, for example, 30 × 10 5 Pa~200×10 5 Pa, preferably 40 x 10 5 Pa~100×10 5 Pa, more preferably 50 x 10 5 Pa~80×10 5Pa, more preferably 50×10 5 Pa~60×10 5 It is Pa.

[0096] Furthermore, from the viewpoint of adhesive strength and boiling sterilization resistance, the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 60°C is preferably higher than the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C. The difference between the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 60°C and the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C is, for example, 1 x 10 5 Pa~10×10 5 Pa, preferably 2 x 10 5 Pa ~ 7 × 10 5 Pa, more preferably 3 x 10 5 Pa~6×10 5 Pa, more preferably 4 x 10 5 Pa~5×10 5 It is Pa.

[0097] In addition, from the viewpoint of adhesive strength and boiling sterilization resistance, the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 25°C is, for example, 500 × 10 5 Pa~3000×10 5 Pa, preferably 1000 x 10 5 Pa~2000×10 5 Pa, more preferably 1200 x 10 5 Pa~1800×10 5 Pa, more preferably 1400 x 10 5 Pa~1600×10 5 It is Pa.

[0098] Furthermore, from the viewpoint of adhesive strength and boiling sterilization resistance, the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 25°C is preferably higher than the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C. The difference between the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 25°C and the tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C is, for example, 500 × 10 5 Pa~3000×10 5 Pa, preferably 1000 x 10 5 Pa~2000×10 5 Pa, more preferably 1200 x 10 5 Pa~1800×10 5 It is Pa.

[0099] From the viewpoints of adhesive strength and boiling sterilization resistance, the glass transition temperature (tan δ) of the cured product of the two-component curing polyurethane adhesive is, for example, -20°C to 80°C, preferably 0 to 60°C, and more preferably 20 to 50°C.

[0100] 2. Manufacturing method of laminated container for boiling sterilization The laminated container for boiling sterilization is produced, for example, by the following method.

[0101] In this method, first, a two-component curing polyurethane adhesive, a first base material layer 2, and a metallized film 4 are prepared (preparation step). Fig. 2A shows the first base material layer 2. In Fig. 2A, the two-component curing polyurethane adhesive and the metallized film 4 are omitted.

[0102] Next, in this method, the first base layer 2 and the metal-deposited film 4 are bonded together with a two-component curing polyurethane adhesive (bonding step).

[0103] More specifically, in this step, the polyol component (main component) and polyisocyanate component (curing agent) of the two-component curing polyurethane adhesive are mixed together.

[0104] The mixing ratio of the polyol component (main component) and the polyisocyanate component (curing agent) is adjusted, for example, based on the mass ratio. More specifically, from the viewpoints of adhesive strength and boiling sterilization resistance, the amount of the polyol component per 1 mass part of the polyisocyanate component is, for example, 3 to 30 mass parts, preferably 5 to 20 mass parts, more preferably 8 to 15 mass parts.

[0105] The mixing ratio of the polyol component (base) and the polyisocyanate component (curing agent) may be adjusted based on the equivalent ratio (NCO / OH) of isocyanate groups to hydroxyl groups of the polyisocyanate component. More specifically, from the viewpoints of adhesive strength and boiling sterilization resistance, the equivalent ratio (NCO / OH) of isocyanate groups of the polyisocyanate component to hydroxyl groups of the polyol component is 1.2 to 6.0, preferably 1.5 to 5.0, more preferably 1.8 to 3.5, and even more preferably 2.0 to 2.5.

[0106] The mixture of the polyol component (main component) and the polyisocyanate component (curing agent) is an adhesive composition. The adhesive composition is preferably diluted with the above-mentioned solvent. The solid content concentration is appropriately set depending on the purpose and application.

[0107] 2B, in this step, for example, the adhesive composition is applied to one surface of the first base material layer 2 using a laminator, and the solvent is evaporated, thereby forming an uncured adhesive layer (first uncured adhesive layer) 9 on one surface of the first base material layer 2.

[0108] 2C, the uncured adhesive layer (first uncured adhesive layer) 9 is bonded to the metallized film 4. More specifically, the metallized film 4 is placed on the uncured adhesive layer 9 so that the metallized layer 8 and the uncured adhesive layer 9 are in contact with each other.

[0109] In this step, the metallized film 4 and the second base layer 6 are bonded together with a two-component curing polyurethane adhesive.

[0110] 2D, for example, the adhesive composition is applied to one surface of the resin film 7 of the metallized film 4 using a laminator, and the solvent is evaporated to form an uncured adhesive layer (second uncured adhesive layer) 9 on one surface of the resin film 7.

[0111] Next, in this step, as shown in FIG. 2E, the uncured adhesive layer (second uncured adhesive layer) 9 and the second base material layer 6 are bonded together by the method described above.

[0112] Thereafter, as shown in FIG. 2F, the uncured adhesive layers (first uncured adhesive layer and second uncured adhesive layer) 9 are aged at room temperature or under elevated temperature. The aging conditions are not particularly limited. The aging temperature is, for example, 20 to 80°C, preferably 40 to 60°C. The aging time is set appropriately.

[0113] This cures the uncured adhesive layer 9. As a result, a first adhesive layer (polyurethane adhesive layer) 3 is formed as a cured product of the two-component curing polyurethane adhesive. The first adhesive layer 3 then bonds the first base material layer 2 and the metallized film 4 together.

[0114] Furthermore, a second adhesive layer (polyurethane adhesive layer) 5 is formed as a cured product of the two-component curing polyurethane adhesive. The second adhesive layer 5 bonds the metallized film 4 and the second base material layer 6 together.

[0115] As a result, a laminate film (laminate) 1 is obtained that includes a first base material layer 2, a first adhesive layer 3, a metallized film 4, a second adhesive layer 5, and a second base material layer 6. In the laminate film 1, the first adhesive layer 3 and the first base material layer 2 are arranged so as to be in contact with each other. Furthermore, the first adhesive layer 3 and the metallized layer 8 are arranged so as to be in contact with each other. Furthermore, the resin film 7 and the second adhesive layer 5 are arranged so as to be in contact with each other. Furthermore, the second adhesive layer 5 and the second base material layer 6 are arranged so as to be in contact with each other.

[0116] Thereafter, although not shown, the laminate film 1 is processed into a container shape by a known method. As a result, a laminate container for boiling sterilization is obtained. The shape of the container is not particularly limited, but examples thereof include a bag shape, a pouch shape, a cup shape, and a bottle shape.

[0117] 3. Other embodiments In the above description, the first adhesive layer 3, the metal vapor deposition film 4, the second adhesive layer 5, and the second base material layer 6 are sequentially laminated and arranged only on one side (the upper side of the paper) of the first base material layer 2.

[0118] On the other hand, although not shown, the first adhesive layer 3, the metal vapor deposition film 4, the second adhesive layer 5, and the second base material layer 6 may be laminated and arranged sequentially on both sides of the first base material layer 2, one side (upper side of the paper) and the other side (lower side of the paper).

[0119] Furthermore, the laminate film 1 does not necessarily have to include the second adhesive layer 5 and the second base material layer 6. The laminate film 1 may include only the first base material layer 2, the first adhesive layer 3, and the metal-deposited film 4.

[0120] From the viewpoints of adhesive strength and boiling sterilization resistance, the laminate film 1 includes a second adhesive layer 5 and a second base material layer 6. Also, from the viewpoints of adhesive strength and boiling sterilization resistance, the first adhesive layer 3, the metallized film 4, the second adhesive layer 5, and the second base material layer 6 are laminated and arranged in this order only on one side (the upper side of the paper) of the first base material layer 2.

[0121] 4. Effects In the laminated container for boiling sterilization and the manufacturing method thereof described above, the first adhesive layer 3 is formed from a two-component curing polyurethane adhesive and is in contact with the metal vapor deposition layer 8.

[0122] In the two-component curing polyurethane adhesive, the polyol component contains a polyester polyol, and the polyisocyanate component contains an isocyanurate derivative of hexamethylene diisocyanate. The cured product of the two-component curing polyurethane adhesive has a tensile storage modulus (E') at 100°C within a specified range. Therefore, the laminated container for boiling sterilization has excellent boiling sterilization resistance.

[0123] Boiling sterilization is heat sterilization at a relatively low temperature (for example, 100° C. or lower). The heating temperature in boiling sterilization is, for example, 80 to 100° C., or preferably 90 to 100° C. The heating time in boiling sterilization is, for example, 0.1 to 12 hours, or preferably 0.5 to 3 hours. [Example]

[0124] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention."

[0125] Example 1 As a two-component curing polyurethane adhesive, the following polyisocyanate component and the following polyol component were prepared.

[0126] Polyisocyanate component: isocyanurate derivative of hexamethylene diisocyanate Polyol component: polyester polyol (aromatic ring concentration 3.37 mmol / g)

[0127] 1 part by mass of the polyisocyanate component and 10 parts by mass of the polyol component were mixed to obtain 11 parts by mass of a mixture (equivalent ratio (NCO / OH) 2.0). Next, the mixture was diluted with a solvent (ethyl acetate) to a solids concentration of 25% by mass. This resulted in an adhesive composition.

[0128] Next, the adhesive composition was applied to the corona-treated surface of the nylon film under the following conditions to obtain a coating film. The coating film was left to stand at room temperature to volatilize the solvent. This resulted in an uncured adhesive layer (first uncured adhesive layer). Coating device; bar coater Basis weight: 3.5g / m 2 (solids) Coating thickness: 14 μm

[0129] Next, the aluminum vapor-deposited surface of the aluminum vapor-deposited PET film was bonded to the uncured adhesive layer (first uncured adhesive layer).

[0130] Next, the adhesive composition was applied to the PET (polyethylene terephthalate) surface of the aluminum-deposited PET film in the same manner as above to obtain a coating film. The coating film was left to stand at room temperature to volatilize the solvent. This resulted in an uncured adhesive layer (second uncured adhesive layer).

[0131] Next, the corona-treated surface of the low-density polyethylene film was bonded to the uncured adhesive layer (second uncured adhesive layer), thereby obtaining an uncured laminate.

[0132] The uncured laminate was then aged at 40°C for 2 days to cure the uncured adhesive layer. This resulted in a laminate film. The laminate film was sealed into a bag (130mm x 175mm) to obtain a laminate container for boiling sterilization.

[0133] Comparative Example 1 The following polyisocyanate component was used. 1 part by mass of the polyisocyanate component was mixed with 6 parts by mass of the polyol component to obtain 7 parts by mass of a mixture (equivalent ratio (NCO / OH) 1.90). A two-component curing polyurethane adhesive, a laminate film, and a laminate container for boiling sterilization were obtained in the same manner as in Example 1.

[0134] Polyisocyanate component: a mixture of 0.7 parts by weight of a trimethylolpropane (TMP) adduct of xylylene diisocyanate (XDI) and 0.3 parts by weight of a biuret derivative of hexamethylene diisocyanate (HDI)

[0135] Comparative Example 2 The following polyol component was used. Also, 1 part by mass of the polyisocyanate component and 16 parts by mass of the polyol component were mixed to obtain 17 parts by mass of a mixture (equivalent ratio (NCO / OH) 1.16). A two-component curing polyurethane adhesive, a laminate film, and a laminate container for boiling sterilization were obtained in the same manner as in Example 1.

[0136] Polyol component: Polycarbonate polyol (aromatic ring concentration 0 mmol / g)

[0137] Comparative Example 3 The following polyisocyanate component and polyol component were used. 1 part by mass of the polyisocyanate component and 16 parts by mass of the polyol component were mixed to obtain 17 parts by mass of a mixture (equivalent ratio (NCO / OH) 1.75). A two-component curing polyurethane adhesive, a laminate film, and a laminate container for boiling sterilization were obtained in the same manner as in Example 1.

[0138] Polyisocyanate component: Biuret derivative of hexamethylene diisocyanate (HDI) Polyol component: polyester polyol (aromatic ring concentration 3.16 mmol / g)

[0139] [evaluation] (1) Dynamic viscoelasticity measurement A mixture of two-component curing polyurethane adhesive (polyisocyanate component and polyol component) was diluted with a solvent (ethyl acetate) so that the solid content concentration was 40 mass %, to obtain a diluted composition.

[0140] On the other hand, a release paper was fixed on a glass plate. Then, the above diluted composition was applied onto the release paper so that the dry thickness was 50 μm. An applicator was used as the application device. In this way, a coating film of the diluted composition was formed.

[0141] The glass plate, release paper, and coating were then placed in a desiccator (N2 atmosphere) for 24 hours, and then placed in a dryer (60°C) for 6 days. This allowed the polyisocyanate component and polyol component to react, and the reaction product was aged. This resulted in a cured two-component curing polyurethane adhesive. The cured product was used as a test sample.

[0142] The test sample was punched into a strip (50 mm long x 5 mm wide). The dynamic viscoelasticity was measured under the following conditions to determine the storage modulus (E') at 25°C, 60°C, and 100°C. Tan δ was also calculated as the glass transition temperature (Tg).

[0143] Measurement conditions Measurement mode: tension Measurement frequency; 10Hz Temperature range: -50℃~200℃ Heating rate: 5℃ / min Length between gauge lines: 20mm Static / dynamic stress ratio: 0.16-0.14

[0144] (2) Boiling resistance (deposition loss) The boiling sterilization laminated container was filled with water. The boiling sterilization laminated container was then subjected to a boiling treatment (95°C x 30 minutes) and cooled in cold water. The appearance of the boiling sterilization laminated container was then observed. The boiling resistance was evaluated according to the following criteria.

[0145] A: No deposition defects were observed after boiling treatment. B: Vapor voids were observed after boiling treatment.

[0146] (3) Water vapor permeability The water vapor permeability of the laminated container for boiling sterilization was measured in accordance with the moisture permeability test method (cup method) for moisture-proof packaging materials of JIS Z 0208 (1976).

[0147] More specifically, approximately 30 g of calcium chloride was sealed in a laminated container (pouch) for boiling sterilization before boiling, and then left to stand for two months under conditions of 40°C and 95% RH. Next, the mass of calcium chloride was measured before and after standing, and the increase in mass W2 after standing relative to the mass W1 before standing (W2 - W1) was calculated.

[0148] Thereafter, the water vapor permeability (water vapor barrier property) of the laminated container for boiling sterilization was evaluated according to the following criteria based on the mass increase (W2-W1) before and after leaving the container.

[0149] A: The mass increase (W2-W1) before and after standing was less than 1 g. B: The mass increase (W2 - W1) before and after standing was 1 g or more.

[0150] [Table 1] [Explanation of symbols]

[0151] 1. Laminating film 2 First base layer 3 First adhesive layer 4 Metallized film 5 Second adhesive layer 6 Second base layer 7 Resin film 8 Metal evaporated layer 9 Uncured adhesive layer

Claims

1. A laminated container for boiling sterilization comprising a laminate, the laminate includes a base layer, a polyurethane adhesive layer disposed on at least one side of the base layer, and a metal vapor-deposited film disposed on at least one side of the polyurethane adhesive layer; the metallized film comprises a resin film and a metallized layer deposited on the resin film; the polyurethane adhesive layer and the metal vapor-deposited layer are arranged to contact each other; the polyurethane adhesive layer contains a cured product of a two-component curing polyurethane adhesive, The two-component curing polyurethane adhesive contains a polyol component and a polyisocyanate component, the polyol component contains a polyester polyol, The polyisocyanate component contains an isocyanurate derivative of hexamethylene diisocyanate, The tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C is 20 x 10 ５ ~100 x 10 ５ A laminated container for boiling sterilization, which is Pa.

2. 2. The laminated container for boil sterilization according to claim 1, wherein the content of the isocyanurate derivative of the hexamethylene diisocyanate is 90% by mass or more relative to the total solid content of the polyisocyanate component.

3. The laminated container for boiling sterilization according to claim 1 or 2, wherein the aromatic ring concentration of the polyester polyol is 3.2 to 3.6 mmol / g.

4. The laminated container for boiling sterilization according to claim 1 or 2, wherein the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate component to the hydroxyl group of the polyol component is 1.5 to 5.

0.

5. a preparation step of preparing a two-component curing polyurethane adhesive, a substrate layer, and a metal vapor deposition film; and a bonding step of bonding the base material layer and the metal vapor-deposited film with the two-component curing polyurethane adhesive, The two-component curing polyurethane adhesive contains a polyol component and a polyisocyanate component, the metallized film comprises a resin film and a metallized layer deposited on the resin film; In the bonding step, a polyurethane adhesive layer is formed by curing the two-component curing polyurethane adhesive, the polyurethane adhesive layer and the metal vapor-deposited layer are arranged to contact each other; the polyol component contains a polyester polyol, The polyisocyanate component contains an isocyanurate derivative of hexamethylene diisocyanate, The tensile storage modulus (E') of the cured product of the two-component curing polyurethane adhesive at 100°C is 20 x 10 ５ Pa ~ 100 x 10 ５ A method for manufacturing a laminated container for boiling sterilization, comprising:

6. 6. The method for producing a laminated container for boil sterilization according to claim 5, wherein the content of the isocyanurate derivative of the hexamethylene diisocyanate is 90% by mass or more relative to the total solid content of the polyisocyanate component.

7. The method for producing a laminated container for boiling sterilization according to claim 5 or 6, wherein the aromatic ring concentration of the polyester polyol is 3.2 to 3.6 mmol / g.

8. The method for producing a laminated container for boil sterilization according to claim 5 or 6, wherein the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate component to the hydroxyl group of the polyol component is 1.5 to 5.0.

Images