Barrier laminate, lid material, and packaging container

Abstract

To enhance the gas barrier properties of a laminate having a barrier base material wherein a vapor deposition film is formed on a stretched polypropylene film and a sealant layer.SOLUTION: A barrier laminate comprising a substrate and a sealant layer in this order in a thickness direction, wherein the substrate is a barrier substrate comprising a polypropylene layer and a vapor deposition film, the polypropylene layer is a layer subjected to a stretching treatment, the vapor deposition film is composed of an inorganic oxide, and a thermal shrinkage ratio (MD1) in an MD direction of the barrier laminate after a heating treatment at 120 °C for 15 minutes is 2.00% or less, and a thermal shrinkage ratio (TD1) in a TD direction is 2.00% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a barrier laminate, a lid material, and a packaging container. [Background technology]

[0002] Films made of polyesters such as polyethylene terephthalate (hereinafter also referred to as "polyester films") are inexpensive and have excellent mechanical properties, chemical stability, heat resistance, and transparency. For these reasons, polyester films have conventionally been used as substrates for forming laminates used in the production of packaging containers.

[0003] Depending on the contents filled in the packaging container, the packaging container is required to have gas barrier properties such as oxygen barrier property and water vapor barrier property. To meet this requirement, a vapor-deposited film containing alumina or silica is formed on the surface of a polyester film (see, for example, Patent Document 1). In recent years, substrates that can replace polyester films have been sought. The use of polyolefin films, particularly polypropylene films, as the substrate has been considered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-053223 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have investigated the use of a stretched polypropylene film (hereinafter also referred to as "stretched polypropylene film") instead of a conventional polyester film. As a result of their investigation, the present inventors have found that a laminate having two elements, a barrier substrate in which a vapor-deposited film is formed on a stretched polypropylene film, and a sealant layer, may not have sufficient gas barrier properties.

[0006] One of the problems to be solved by the present disclosure is to improve the gas barrier properties of a laminate having a barrier substrate in which a vapor-deposited film is formed on a stretched polypropylene film, and a sealant layer. [Means for solving the problem]

[0007] The barrier laminate of the present disclosure comprises a substrate and a sealant layer in this order in the thickness direction. The substrate is a barrier substrate comprising a polypropylene resin layer and a vapor-deposited film. The polypropylene resin layer is a layer that has been subjected to a stretching treatment. The vapor-deposited film is composed of an inorganic oxide. After heat treatment at 120°C for 15 minutes, the barrier laminate has a MD heat shrinkage rate (MD1) of 2.00% or less and a TD heat shrinkage rate (TD1) of 2.00% or less. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to improve the gas barrier properties of a laminate having a barrier substrate in which a vapor-deposited film is formed on a stretched polypropylene film, and a sealant layer. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 5] FIG. 5 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 6] FIG. 6 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 7] FIG. 7 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 8]FIG. 8 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 9] FIG. 9 is a schematic cross-sectional view showing one embodiment of a barrier laminate. [Figure 10] FIG. 10 is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus. [Figure 11] FIG. 11 is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus. [Figure 12] FIG. 12 is a schematic cross-sectional view showing another embodiment of the vapor deposition apparatus. [Figure 13] FIG. 13 is a front view showing one embodiment of a packaging container. [Figure 14] FIG. 14 is a perspective view showing one embodiment of a packaging container. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed description may be omitted as appropriate.

[0011] In the following description, each of the components (for example, polypropylene, α-olefin, resin material, additive, adhesive resin, inorganic oxide, and gas barrier resin) may be used alone or in combination of two or more.

[0012] [Barrier laminate] The barrier laminate of the present disclosure includes a substrate and a sealant layer in this order in the thickness direction. The substrate is a barrier substrate comprising a polypropylene resin layer and a vapor-deposited film.

[0013] The barrier laminate of the present disclosure preferably comprises a first substrate, a second substrate, and a sealant layer in this order in the thickness direction. Either the first substrate or the second substrate is a barrier substrate comprising a polypropylene resin layer and a vapor-deposited film. The other of the first substrate and the second substrate is a polypropylene resin substrate that has been subjected to a stretching treatment. In this embodiment, a barrier substrate is used as either the first substrate or the second substrate, and a polypropylene resin substrate is used as the other of the first substrate and the second substrate, but in other embodiments, both the first substrate and the second substrate may be a barrier substrate.

[0014] The polypropylene resin layer has been subjected to a stretching treatment. The vapor-deposited film is composed of an inorganic oxide.

[0015] The barrier laminate of the present disclosure has a thermal shrinkage rate in the MD direction (MD1) of 2.00% or less and a thermal shrinkage rate in the TD direction (TD1) of 2.00% or less after heat treatment at 120°C for 15 minutes.

[0016] 1 to 9 are schematic cross-sectional views showing an embodiment of a barrier laminate. 1 includes a barrier substrate 20 as a base material, an adhesive layer 40, and a sealant layer 30, in this order in the thickness direction. The barrier substrate 20 includes a polypropylene resin layer 22 and a vapor-deposited film 24. In this example, the polypropylene resin layer 22 constitutes the outermost layer of the barrier laminate 1, and the vapor-deposited film 24 is in contact with the adhesive layer 40.

[0017] FIG. 2 is the same as FIG. 1 except that the barrier substrate 20 has a surface coating layer or surface resin layer 23 between the polypropylene resin layer 22 and the vapor-deposited film 24 .

[0018] 3 is the same as FIG. 1 except that the barrier substrate 20 includes, in this order in the thickness direction, a polypropylene resin layer 22, a surface coating layer or surface resin layer 23, a vapor deposition film 24, and a barrier coating layer 25. In this example, the barrier coating layer 25 contacts the adhesive layer 40.

[0019] 4 includes, in the thickness direction, a polypropylene resin substrate 10 as a first substrate, an adhesive layer 40A, a barrier substrate 20 as a second substrate, an adhesive layer 40B, and a sealant layer 30. The barrier substrate 20 includes a polypropylene resin layer 22 and a vapor-deposited film 24. In this example, the polypropylene resin layer 22 is in contact with the adhesive layer 40B, and the vapor-deposited film 24 is in contact with the adhesive layer 40A.

[0020] FIG. 5 is the same as FIG. 4 except that the barrier substrate 20 has a surface coating layer or surface resin layer 23 between the polypropylene resin layer 22 and the vapor-deposited film 24 .

[0021] 6 is the same as FIG. 4 except that the barrier substrate 20 includes, in this order in the thickness direction, a polypropylene resin layer 22, a surface coating layer or surface resin layer 23, a vapor deposition film 24, and a barrier coating layer 25. In this example, the barrier coating layer 25 contacts the adhesive layer 40A.

[0022] 7 includes, in the thickness direction, a barrier substrate 20 as a first substrate, an adhesive layer 40A, a polypropylene resin substrate 10 as a second substrate, an adhesive layer 40B, and a sealant layer 30. The barrier substrate 20 includes a polypropylene resin layer 22 and a vapor-deposited film 24. In this example, the polypropylene resin layer 22 constitutes the outermost layer of the barrier laminate 1, and the vapor-deposited film 24 is in contact with the adhesive layer 40A.

[0023] FIG. 8 is the same as FIG. 7 except that the barrier substrate 20 has a surface coating layer or surface resin layer 23 between the polypropylene resin layer 22 and the vapor-deposited film 24 .

[0024] 9 is the same as FIG. 7 except that the barrier substrate 20 includes, in this order in the thickness direction, a polypropylene resin layer 22, a surface coating layer or surface resin layer 23, a vapor deposition film 24, and a barrier coating layer 25. In this example, the barrier coating layer 25 contacts the adhesive layer 40A.

[0025] In one embodiment, the barrier laminate of the present disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer, which can further improve gas barrier properties (particularly oxygen barrier properties and water vapor barrier properties).

[0026] When the first substrate is a barrier substrate, in one embodiment, the first substrate is arranged so that the vapor-deposited film faces the sealant layer side and the polypropylene resin layer faces the side opposite to the sealant layer. When the second substrate is a barrier substrate, in one embodiment, the second substrate is arranged so that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer, or the second substrate is arranged so that the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces the first substrate. Among these, when the second substrate is a barrier substrate, from the viewpoint of further suppressing deterioration of the vapor-deposited film, it is preferable that the second substrate is arranged so that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer.

[0027] In one embodiment of the barrier laminate of the present disclosure, the first substrate is a polypropylene resin substrate, and the second substrate is a barrier substrate (see FIGS. 4 to 6). In this embodiment, the barrier laminate comprises a polypropylene resin substrate, a barrier substrate, and a sealant layer, in this order in the thickness direction. A barrier laminate having such a configuration adequately protects the vapor-deposited film when subjected to heat treatment or the like, and exhibits even higher gas barrier properties. Furthermore, the barrier laminate of the above embodiment has a smaller heat shrinkage rate when subjected to heat treatment, and therefore has even better suitability for bag formation.

[0028] In the present disclosure, the expression "AAA composed of polypropylene" means that the main component of the AAA is polypropylene, but is not limited to a configuration in which the AAA is composed solely of polypropylene. The AAA may contain components other than polypropylene. Specifically, the polypropylene content in the AAA is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0029] <Barrier substrate> The barrier laminate of the present disclosure includes a barrier substrate as a substrate. The barrier substrate comprises a polypropylene resin layer and a vapor-deposited film. In one embodiment, the barrier substrate comprises a polypropylene resin layer and a vapor-deposited film provided on one surface of the resin layer. The barrier substrate may comprise a surface coating layer or a surface resin layer between the polypropylene resin layer and the vapor-deposited film. The barrier substrate may comprise a barrier coating layer on the vapor-deposited film.

[0030] The barrier laminate of the present disclosure preferably comprises a first substrate, a second substrate, and a sealant layer in this order in the thickness direction. The barrier substrate constitutes the first substrate or the second substrate. When the first substrate is a polypropylene resin substrate, the barrier substrate constitutes the second substrate. When the second substrate is a polypropylene resin substrate, the barrier substrate constitutes the first substrate. In this embodiment, a barrier substrate is used as either the first substrate or the second substrate, and a polypropylene resin substrate is used as the other of the first substrate and the second substrate, but in other embodiments, both the first substrate and the second substrate may be a barrier substrate.

[0031] (Polypropylene resin layer) The polypropylene resin layer is made of polypropylene. By providing the barrier substrate with a layer made of polypropylene, for example, it is possible to improve the oil resistance of a packaging container produced using the barrier substrate.

[0032] The polypropylene may be any of a homopolymer, a random copolymer, and a block copolymer, or may be a mixture of two or more selected from these.

[0033] A propylene homopolymer is a polymer of propylene alone. A propylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene. A propylene block copolymer is a copolymer having a polymer block of propylene and a polymer block of an α-olefin other than propylene.

[0034] Examples of α-olefins include α-olefins having 2 or more and 20 or less carbon atoms, and specific examples include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene.

[0035] Among polypropylenes, it is preferable to use a homopolymer or a random copolymer from the viewpoint of transparency. When emphasis is placed on the rigidity and heat resistance of the packaging container, it is preferable to use a homopolymer. When emphasis is placed on the impact resistance of the packaging container, it is preferable to use a random copolymer.

[0036] In one embodiment, the melt flow rate (MFR) of the polypropylene may be 0.1 g / 10 min or more and 50 g / 10 min or less, or 0.3 g / 10 min or more and 30 g / 10 min or less, from the viewpoint of film-forming ability and processability. The MFR of the polypropylene is measured in accordance with ASTM D1238 at a temperature of 230°C and a load of 2.16 kg.

[0037] As the polypropylene, biomass-derived polypropylene or mechanically recycled or chemically recycled polypropylene may be used.

[0038] The content of polypropylene in the polypropylene resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more.

[0039] The polypropylene resin layer may contain a resin material other than polypropylene, such as polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

[0040] The polypropylene resin layer may contain additives such as crosslinking agents, antioxidants, antiblocking agents, slip agents, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0041] The polypropylene resin layer is a layer that has been subjected to a stretching treatment. This can improve, for example, the heat resistance, impact resistance, water resistance, and dimensional stability of the barrier laminate. A barrier laminate having such a resin layer is suitable, for example, as a packaging material for forming a packaging container that is subjected to a boiling treatment or a retort treatment. The stretching treatment may be uniaxial stretching or biaxial stretching.

[0042] When stretching in the machine direction (machine direction, MD, of the substrate), the stretching ratio is preferably 2 to 15, more preferably 5 to 13. When stretching in the transverse direction (direction perpendicular to the MD, TD), the stretching ratio is preferably 2 to 15, more preferably 5 to 13. By setting the stretching ratio to 2 or more, the strength and heat resistance of the polypropylene resin layer can be further improved, and the printability of the polypropylene resin layer can be improved. From the viewpoint of the breaking limit of the polypropylene resin layer, the stretching ratio is preferably 15 or less.

[0043] In one embodiment, the polypropylene resin layer may be subjected to a surface treatment. This can improve, for example, the adhesion between the polypropylene resin layer and other layers. Examples of surface treatment methods include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment; and chemical treatments such as oxidation treatment using chemicals. An easy-adhesion layer may be provided on the surface of the polypropylene resin layer.

[0044] The polypropylene resin layer may have a single-layer structure or a multi-layer structure. The thickness of the polypropylene resin layer is preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. When the thickness is equal to or more than the lower limit, for example, the strength and heat resistance of the barrier laminate can be further improved. When the thickness is equal to or less than the upper limit, for example, the processability of the barrier laminate can be further improved.

[0045] The barrier substrate may have a printed layer on the surface of the polypropylene resin layer. The image formed on the printed layer is not particularly limited, and may include letters, patterns, symbols, and combinations thereof. The printed layer may be formed using ink derived from biomass, which further reduces the environmental impact.

[0046] Examples of methods for forming the printed layer include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. Among these, flexographic printing is preferred from the viewpoint of reducing environmental impact.

[0047] (surface coating layer) In one embodiment, the barrier substrate includes a surface coating layer containing a resin material having a polar group between the polypropylene resin layer and the vapor-deposited film. By providing the surface coating layer containing a resin material having a polar group, it is possible to improve the adhesion of the vapor-deposited film formed on the surface coating layer and also improve the gas barrier properties.

[0048] In this embodiment, the barrier substrate comprises a resin substrate having a polypropylene resin layer and a surface coating layer, and a vapor-deposited film provided on the surface coating layer, the polypropylene resin layer, the surface coating layer, and the vapor-deposited film being arranged in this order in the thickness direction of the barrier substrate.

[0049] The polar group refers to a group containing one or more heteroatoms, and examples thereof include an ester group, an epoxy group, a hydroxyl group, an amino group, an amide group, a urethane group, a carboxyl group, a carbonyl group, a carboxylic anhydride group, a sulfo group, a thiol group, and a halogen group. Among these, from the viewpoint of lamination properties of the packaging container, the carboxyl group, the carbonyl group, the ester group, the hydroxyl group, the amino group, the amide group, and the urethane group are preferred, and the carboxyl group, the hydroxyl group, the amide group, and the urethane group are more preferred.

[0050] Examples of resin materials having a polar group include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyester, polyethyleneimine, hydroxyl group-containing (meth)acrylic resin, polyamides such as nylon 6, nylon 6,6, MXD nylon, and amorphous nylon, and polyurethane. Among these, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, hydroxyl group-containing (meth)acrylic resin, polyamide, and polyurethane are more preferred.

[0051] The surface coating layer can be formed using, for example, an aqueous emulsion or a solvent-based emulsion. Examples of aqueous emulsions include polyamide-based emulsions, polyethylene-based emulsions, and polyurethane-based emulsions. Examples of solvent-based emulsions include (meth)acrylic resin-based emulsions and polyester-based emulsions.

[0052] The content of the resin material having a polar group in the surface coating layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The surface coating layer may contain a resin material other than the resin material having a polar group. The surface coating layer may contain the above-mentioned additives.

[0053] The ratio of the thickness of the surface coating layer to the total thickness of the resin substrate is preferably 0.08% or more and 20% or less, more preferably 0.2% or more and 15% or less, even more preferably 1% or more and 10% or less, and even more preferably 1% or more and 5% or less. When this ratio is equal to or greater than the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved. When this ratio is equal to or less than the upper limit, for example, the processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0054] The thickness of the surface coating layer is preferably 0.02 μm to 10 μm, more preferably 0.05 μm to 10 μm, even more preferably 0.1 μm to 10 μm, and even more preferably 0.2 μm to 5 μm. When the thickness is equal to or greater than the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved. When the thickness is equal to or less than the upper limit, for example, the processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0055] For example, a resin substrate can be produced by forming a resin film from polypropylene or a resin composition containing polypropylene using a T-die method, an inflation method, or the like, and then stretching the resin film. A coating liquid for forming a surface coating layer is applied to the stretched resin film and dried.

[0056] (Surface resin layer) In one embodiment, the barrier substrate has a surface resin layer between the polypropylene resin layer and the vapor-deposited film, the surface resin layer containing a resin material having a melting point of 180° C. or higher (hereinafter also referred to as a "high-melting-point resin material") By providing a surface resin layer containing a high-melting-point resin material, it is possible to improve the adhesion of the vapor-deposited film formed on the surface resin layer and also improve the gas barrier properties.

[0057] In this embodiment, the barrier substrate comprises a resin substrate having a polypropylene resin layer and a surface resin layer, and a vapor-deposited film provided on the surface resin layer, the polypropylene resin layer, the surface resin layer, and the vapor-deposited film being arranged in this order in the thickness direction.

[0058] The melting point of the high-melting-point resin material is preferably 185° C. or higher, more preferably 190° C. or higher, and even more preferably 205° C. or higher. When the melting point is equal to or higher than the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved.

[0059] The melting point of the high-melting-point resin material is preferably 265° C. or lower, more preferably 260° C. or lower, and even more preferably 250° C. or lower, which can improve, for example, the film-forming properties of the resin substrate.

[0060] In this specification, the melting point can be measured in accordance with JIS K7121:2012 (Method for measuring transition temperature of plastics). Specifically, the melting point can be determined by measuring a DSC curve using a differential scanning calorimetry (DSC) device at a temperature rise rate of 10°C / min.

[0061] The difference between the melting point of the high-melting-point resin material contained in the surface resin layer and the melting point of the polypropylene contained in the polypropylene resin layer is preferably 20°C or more and 80°C or less, more preferably 20°C or more and 60°C or less. When this difference is the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved. When this difference is the upper limit or less, for example, the film-forming properties of the resin substrate can be further improved.

[0062] The high-melting-point resin material preferably has a polar group. The polar group refers to a group containing one or more heteroatoms, and examples thereof include ester groups, epoxy groups, hydroxyl groups, amino groups, amide groups, urethane groups, carboxy groups, carbonyl groups, carboxylic anhydride groups, sulfo groups, thiol groups, and halogen groups. Among these, from the viewpoint of the gas barrier properties and laminate strength of the packaging container, hydroxyl groups, ester groups, amino groups, amide groups, carboxy groups, and carbonyl groups are preferred, and amide groups are more preferred.

[0063] The high-melting-point resin material may have a melting point of 180°C or higher, and examples thereof include polyolefin, vinyl resin, (meth)acrylic resin, polyamide, polyimide, polyester, cellulose resin, and ionomer resin. For example, a resin material having a melting point of 180°C or higher and a polar group is preferred, and more preferred are ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyester, and polyamides such as nylon 6, nylon 6,6, MXD nylon, and amorphous nylon.

[0064] The content of the high-melting-point resin material in the surface resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0065] The surface resin layer may contain a resin material other than the high-melting-point resin material. The surface resin layer may contain the above-mentioned additives. The surface resin layer may be subjected to the above-mentioned surface treatment.

[0066] The ratio of the thickness of the surface resin layer to the total thickness of the resin substrate is preferably 1% or more and 10% or less, more preferably 1% or more and 5% or less. When this ratio is equal to or greater than the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved. When this ratio is equal to or less than the upper limit, for example, the film-forming property and processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0067] The thickness of the surface resin layer is preferably 0.1 μm to 5 μm, more preferably 0.1 μm to 4 μm. When the thickness is equal to or greater than the lower limit, for example, the adhesion of the vapor-deposited film can be further improved, the gas barrier properties can be further improved, and the laminate strength of the packaging container can be further improved. When the thickness is equal to or less than the upper limit, for example, the film-forming property and processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0068] In one embodiment, the resin substrate may include an adhesive resin layer between the polypropylene resin layer and the surface resin layer, thereby improving adhesion between these layers.

[0069] The adhesive resin layer can be formed, for example, from an adhesive resin. Examples of adhesive resins include polyether, polyester, polyurethane, silicone resin, epoxy resin, vinyl resin, phenolic resin, polyolefin, and acid-modified polyolefin. Among these, from the viewpoint of the recyclability of the packaging container, polyolefin and acid-modified polyolefin are preferred, and polypropylene and acid-modified polyolefin are more preferred.

[0070] The thickness of the adhesive resin layer is, for example, 1 μm or more and 15 μm or less. When the thickness is 1 μm or more, for example, the adhesion between the polypropylene resin layer and the surface resin layer can be further improved. When the thickness is 15 μm or less, for example, the processability of the resin substrate can be further improved.

[0071] In one embodiment, the resin substrate having a polypropylene resin layer and, if necessary, an adhesive resin layer and a surface resin layer is a coextruded stretched resin film. The coextruded stretched resin film can be produced, for example, by forming a laminated film using a T-die method or an inflation method, and then stretching the laminated film. By forming the film using the inflation method, the laminated film may be stretched simultaneously.

[0072] The stretching treatment may be uniaxial stretching or biaxial stretching. The stretching ratio in the MD direction is preferably 2 to 15 times, more preferably 5 to 13 times. The stretching ratio in the TD direction is preferably 2 to 15 times, more preferably 5 to 13 times.

[0073] (evaporated film) The barrier substrate comprises a vapor-deposited film made of an inorganic oxide. In one embodiment, the barrier substrate comprises a vapor-deposited film on the surface coating layer. In one embodiment, the barrier substrate comprises a vapor-deposited film on the surface resin layer. This can improve the gas barrier properties of the barrier laminate, specifically the oxygen barrier properties and water vapor barrier properties. A packaging container made using the barrier laminate can suppress weight loss of the contents filled in the packaging container.

[0074] Examples of inorganic oxides include aluminum oxide (alumina), silicon oxide (silica), magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among these, silica, silicon carbide oxide, and alumina are preferred.

[0075] In one embodiment, silica is more preferable as the inorganic oxide because it does not require aging treatment after forming the vapor-deposited film.In one embodiment, carbon-containing silicon oxide is more preferable as the inorganic oxide because it can suppress deterioration of the gas barrier property even when the barrier laminate is bent.

[0076] The thickness of the vapor-deposited film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less. When the thickness is equal to or greater than the lower limit, for example, the oxygen barrier property and water vapor barrier property of the barrier laminate can be further improved. When the thickness is equal to or less than the upper limit, for example, the occurrence of cracks in the vapor-deposited film can be suppressed and the recyclability of the packaging container can be improved.

[0077] The surface of the vapor-deposited film is preferably subjected to the above-mentioned surface treatment, which can improve the adhesion between the vapor-deposited film and the adjacent layer.

[0078] Examples of methods for forming a vapor-deposited film include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

[0079] The vapor-deposited film may be a single layer formed by a single vapor deposition process, or may be a multilayer formed by multiple vapor deposition processes. When the vapor-deposited film is a multilayer film, each layer may be composed of the same inorganic oxide or different inorganic oxides. Each layer may be formed by the same method or different methods.

[0080] A plasma-assisted vacuum deposition apparatus can be used as an apparatus for forming a vapor-deposited film by the PVD method. One embodiment of a method for forming a vapor-deposited film using the plasma-assisted vacuum deposition apparatus will be described below.

[0081] 10 and 11, the vacuum film formation apparatus includes a vacuum vessel A, an unwinding section B, a film formation drum C, a winding section D, a transport roll E, an evaporation source F, a reactive gas supply section G, an evaporation protection box H, an evaporation material I, and a plasma gun J. Fig. 10 is a schematic cross-sectional view of the vacuum film formation apparatus in the XZ plane. Fig. 11 is a schematic cross-sectional view of the vacuum film formation apparatus in the XY plane.

[0082] As shown in Figure 10, a substrate S wound around a film-forming drum C is placed in the upper part of a vacuum chamber A, with the surface on which the vapor deposition film is to be formed facing downward. An electrically grounded deposition-protective box H is placed below the film-forming drum C in the vacuum chamber A. An evaporation source F is placed on the bottom of the deposition-protective box H. The film-forming drum C is placed in the vacuum chamber A so that the substrate S wound around the film-forming drum C is positioned facing the top surface of the evaporation source F at a certain distance. Transport rolls E are placed between the unwinding section B and the film-forming drum C, and between the film-forming drum C and the winding section D. The vacuum chamber A is connected to a vacuum pump (not shown). The evaporation source F holds a vapor deposition material I and is equipped with a heating device (not shown). A reactive gas supply section G supplies a reactive gas (such as oxygen, nitrogen, helium, argon, or a mixture thereof) that reacts with the evaporated vapor deposition material I.

[0083] The evaporation material I is heated and evaporated from the evaporation source F and is irradiated onto the substrate S, and at the same time, plasma is also irradiated onto the substrate S from the plasma gun J, forming an evaporated film on the substrate S. Details of the above film formation method are disclosed in Japanese Patent Application Laid-Open No. 2011-214089.

[0084] The plasma generating device used in plasma chemical vapor deposition can be a device that generates high-frequency plasma, pulsed wave plasma, microwave plasma, or the like. A device with two or more film formation chambers can also be used. Such a device is preferably equipped with a vacuum pump so that each film formation chamber can be maintained at a vacuum. The vacuum level in each deposition chamber was 1×10 to 1×10 -6 Pa is preferred.

[0085] An embodiment of a method for forming a vapor-deposited film using a plasma generating device will be described below. The substrate is sent into the film-forming chamber and transported at a predetermined speed onto the circumferential surface of the cooling electrode drum via an auxiliary roll. Next, a mixed gas composition containing a film-forming monomer gas containing an inorganic oxide, oxygen gas, an inert gas, etc. is supplied from a gas supply device into the film-forming chamber, and plasma is generated on the substrate by glow discharge. This plasma is then irradiated to form a vapor-deposited film containing an inorganic oxide on the substrate. Details of the above film formation method are disclosed in Japanese Patent Application Laid-Open No. 2012-076292.

[0086] FIG. 12 is a schematic diagram showing the configuration of a plasma chemical vapor deposition apparatus used in the CVD method. In one embodiment, as shown in FIG. 12, a plasma enhanced chemical vapor deposition apparatus unwinds a substrate S from a winding section B1 located within a vacuum vessel A1 and transports the substrate S onto the circumferential surface of a cooling electrode drum C1 at a predetermined speed via a transport roll E1. Oxygen, nitrogen, helium, argon, and a mixture thereof are supplied from a reactive gas supply section G1, and a film-forming monomer gas and the like are supplied from a raw material gas supply section I1. A vapor deposition mixed gas composition comprising these gases is prepared and introduced into the vacuum vessel A1 through a raw material supply nozzle H1. Plasma is then generated by glow discharge plasma F1 on the substrate S transported onto the circumferential surface of the cooling electrode drum C1, and the substrate is irradiated with this plasma to form a vapor deposition film on the substrate S. A predetermined power is applied to the cooling electrode drum C1 from a power source K1 located outside the vacuum vessel A1, and a magnet J1 is positioned near the cooling electrode drum C1 to promote plasma generation. After the vapor deposition film is formed, the substrate S is wound onto a winding section D1 via the transport roll E1 at a predetermined winding speed. In FIG. 12, L1 represents a vacuum pump.

[0087] The apparatus used in the method for forming a vapor-deposited film may be a continuous vapor-deposited film-forming apparatus equipped with a plasma pretreatment chamber and a film-forming chamber. One embodiment of the method for forming a vapor-deposited film using this apparatus will be described below.

[0088] In the plasma pretreatment chamber, the substrate is irradiated with plasma from a plasma supply nozzle, and then in the film formation chamber, a vapor deposition film is formed on the plasma-treated substrate. Details of the above film formation method are disclosed in WO 2019 / 087960.

[0089] The vapor-deposited film in the barrier substrate is preferably a vapor-deposited film formed by a CVD method, and more preferably a carbon-containing silicon oxide vapor-deposited film formed by a CVD method, which can prevent a decrease in gas barrier properties even when the barrier laminate is bent.

[0090] The carbon-containing silicon oxide vapor-deposited film contains silicon, oxygen, and carbon. In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the carbon content C is preferably 3% to 50%, more preferably 5% to 40%, and even more preferably 10% to 35%, relative to the total of the three elements silicon, oxygen, and carbon (100%). By setting the carbon content C within the above range, for example, deterioration in gas barrier properties can be suppressed even when the barrier laminate is bent. In this specification, the proportion of each element is on a molar basis.

[0091] In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the silicon content Si is preferably 1% to 45%, more preferably 3% to 38%, and even more preferably 8% to 33%, relative to 100% of the total of the three elements silicon, oxygen, and carbon. The oxygen content O is preferably 10% to 70%, more preferably 20% to 65%, and even more preferably 25% to 60%, relative to 100% of the total of the three elements silicon, oxygen, and carbon. By setting the silicon content Si and the oxygen content O within the above ranges, for example, deterioration of the gas barrier properties can be further suppressed even when the barrier laminate is bent.

[0092] In one embodiment of the carbon-containing silicon oxide vapor-deposited film, the oxygen ratio O is preferably higher than the carbon ratio C, and the silicon ratio Si is preferably lower than the carbon ratio C. The oxygen ratio O is preferably higher than the silicon ratio Si, that is, the ratios preferably decrease in the order of ratio O, ratio C, and ratio Si. This makes it possible to further suppress deterioration in gas barrier properties, for example, even when the barrier laminate is bent.

[0093] The proportions C, Si, and O in the carbon-containing silicon oxide vapor-deposited film can be measured by narrow scan analysis using X-ray photoelectron spectroscopy (XPS) under the following measurement conditions.

[0094] (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectral collection conditions Incident X-ray: MgKα (monochromatic X-ray, hν=1253.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): approx. 6 mm diameter Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching range: 10mmφ Ion sputtering time: 30 seconds, and the spectrum was collected.

[0095] (barrier coat layer) In one embodiment, the barrier substrate may further include a barrier coat layer on the vapor-deposited film. That is, the barrier substrate may further include a barrier coat layer on the surface of the vapor-deposited film opposite to the surface on the polypropylene resin layer side. This can improve, for example, the oxygen barrier property and water vapor barrier property of the barrier laminate.

[0096] In one embodiment, the barrier coat layer contains a gas barrier resin, such as an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyamides such as nylon 6, nylon 6,6, and polymetaxylylene adipamide, polyurethane, or (meth)acrylic resin.

[0097] The content of the gas barrier resin in the barrier coat layer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Such a configuration can improve, for example, the gas barrier properties of the barrier coat layer. The barrier coat layer may contain the above-mentioned additives.

[0098] The thickness of the barrier coat layer containing the gas barrier resin is preferably 0.01 μm to 10 μm, more preferably 0.1 μm to 5 μm. By making the thickness of the barrier coat layer 0.01 μm or more, for example, the gas barrier property can be further improved. By making the thickness of the barrier coat layer 10 μm or less, for example, the processability of the barrier laminate and the recyclability of the packaging container can be improved.

[0099] The barrier coat layer can be formed, for example, by applying and drying a coating liquid obtained by dissolving or dispersing a material such as a gas barrier resin in water or an appropriate organic solvent.

[0100] In another embodiment, the barrier coat layer is a gas barrier coating film formed by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and optionally adding water, an organic solvent, and a sol-gel catalyst to obtain a gas barrier composition, which is then applied to a vapor-deposited film and dried. The gas barrier coating film contains a hydrolysis polycondensate obtained by hydrolyzing and polycondensing the metal alkoxide or the like by a sol-gel method. By providing such a barrier coat layer on the vapor-deposited film, the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0101] The metal alkoxide is represented by, for example, formula (1). R 1 n M(OR 2 ) m (1) In formula (1), R 1 and R 2 each independently represents an organic group having 1 to 8 carbon atoms; M represents a metal atom; n represents an integer of 0 or more; m represents an integer of 1 or more; and n+m represents the valence of M.

[0102] R 1 and R 2 Examples of the organic group include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-hexyl group, and an n-octyl group. The metal atom M is, for example, silicon, zirconium, titanium or aluminum.

[0103] Examples of metal alkoxides include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0104] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Depending on the desired physical properties, such as oxygen barrier property, water vapor barrier property, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of the metal alkoxide.

[0105] The surface of the gas barrier coating film preferably has a silicon to carbon atom ratio (Si / C) of 1.60 or less, more preferably 0.50 to 1.60, and even more preferably 0.90 to 1.35, as measured by X-ray photoelectron spectroscopy (XPS). When the ratio is equal to or less than the upper limit, degradation of the gas barrier properties can be suppressed, for example, even when the barrier laminate is bent. When the ratio is equal to or greater than the lower limit, degradation of the gas barrier properties can be suppressed, for example, even when heating is performed, such as by heat sealing, when producing a packaging container using the barrier laminate.

[0106] The above range of the ratio of silicon atoms to carbon atoms can be achieved by appropriately adjusting the amount of metal alkoxide used relative to the water-soluble polymer. In this specification, the ratio of silicon atoms to carbon atoms is on a molar basis.

[0107] The ratio of silicon atoms to carbon atoms by X-ray photoelectron spectroscopy (XPS) can be measured by narrow scan analysis under the following measurement conditions.

[0108] (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectral collection conditions Incident X-ray: MgKα (monochromatic X-ray, hν=1253.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): approx. 6 mm diameter Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching range: 10mmφ Ion sputtering time: 30 seconds + 30 seconds + 60 seconds (total 120 seconds) Collecting spectra

[0109] As the silane coupling agent, a known organoalkoxysilane containing an organic reactive group can be used, and an organoalkoxysilane having an epoxy group is preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of the silane coupling agent used is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the metal alkoxide.

[0110] The gas barrier composition may contain water in an amount of preferably 0.1 to 100 moles, more preferably 0.5 to 60 moles, per mole of metal alkoxide. By adjusting the water content to the lower limit or higher, for example, the oxygen barrier property and water vapor barrier property of the barrier laminate can be improved. By adjusting the water content to the upper limit or lower, for example, the hydrolysis reaction can be carried out quickly.

[0111] The gas barrier composition may contain an organic solvent, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0112] The sol-gel catalyst is preferably an acid or an amine compound. Examples of the acid include mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid; and organic acids such as acetic acid and tartaric acid. The amount of the acid used is preferably 0.001 mol or more and 0.05 mol or less per mol of the total molar amount of the metal alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent.

[0113] The amine compound is preferably a tertiary amine that is substantially insoluble in water and soluble in an organic solvent, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. The amount of the amine compound used is preferably 0.01 to 1.0 parts by mass, more preferably 0.03 to 0.3 parts by mass, relative to 100 parts by mass of the total amount of the metal alkoxide and the silane coupling agent.

[0114] Examples of methods for applying the gas barrier composition include roll coating using a gravure roll coater or the like, spray coating, spin coating, dipping, brush coating, bar coating, and applicator coating.

[0115] Hereinafter, one embodiment of the method for forming a gas barrier coating film will be described. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually progresses within the composition. The composition is then coated onto the vapor-deposited film by a conventional method and dried. This drying process further promotes polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one) to form a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above process. For example, the coated composition is heated at a temperature of preferably 20°C to 150°C, more preferably 50°C to 120°C, and even more preferably 70°C to 100°C, for 1 second to 10 minutes. This process allows the formation of a gas barrier coating film.

[0116] The thickness of the gas barrier coating film is preferably 0.01 μm to 100 μm, more preferably 0.1 μm to 50 μm, and even more preferably 0.1 μm to 5 μm, which can improve the gas barrier properties, suppress the occurrence of cracks in the vapor-deposited film, and improve the recyclability of the packaging container, for example.

[0117] <Polypropylene resin base material> The barrier laminate of the present disclosure preferably comprises a first substrate, a second substrate, and a sealant layer in this order in the thickness direction, with the polypropylene resin substrate constituting the first substrate or the second substrate. The polypropylene resin substrate is made of polypropylene. By providing the barrier laminate with a substrate made of polypropylene, for example, it is possible to improve the oil resistance of a packaging container produced using the barrier laminate.

[0118] The polypropylene may be any of a homopolymer, a random copolymer, and a block copolymer, or may be a mixture of two or more selected from these, the details of which are as described above.

[0119] Among polypropylenes, it is preferable to use a homopolymer or a random copolymer from the viewpoint of transparency. When emphasis is placed on the rigidity and heat resistance of the packaging container, it is preferable to use a homopolymer. When emphasis is placed on the impact resistance of the packaging container, it is preferable to use a random copolymer.

[0120] In one embodiment, the MFR of the polypropylene may be 0.1 g / 10 min or more and 50 g / 10 min or less, or 0.3 g / 10 min or more and 30 g / 10 min or less, from the viewpoint of film-forming properties and processability.

[0121] As the polypropylene, biomass-derived polypropylene or mechanically recycled or chemically recycled polypropylene may be used.

[0122] The polypropylene content in the polypropylene resin substrate is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more.

[0123] The polypropylene resin substrate may contain resin materials other than polypropylene, such as polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polypropylene resin substrate may contain the above-mentioned additives.

[0124] The polypropylene resin substrate is a substrate that has been subjected to a stretching treatment. This can improve, for example, the heat resistance, impact resistance, water resistance, and dimensional stability of the barrier laminate. A barrier laminate including such a substrate is suitable, for example, as a packaging material for forming a packaging container that is subjected to a boiling treatment or a retort treatment. The stretching treatment may be uniaxial stretching or biaxial stretching.

[0125] The stretching ratio when stretching in the MD direction is preferably 2 to 15 times, more preferably 5 to 13 times. The stretching ratio when stretching in the TD direction is preferably 2 to 15 times, more preferably 5 to 13 times. By setting the stretching ratio to 2 times or more, the strength and heat resistance of the polypropylene resin substrate can be further improved, and the printability of the polypropylene resin substrate can be improved. From the viewpoint of the breaking limit of the polypropylene resin substrate, the stretching ratio is preferably 15 times or less.

[0126] In one embodiment, the polypropylene resin substrate may be subjected to the above-mentioned surface treatment, which can improve the adhesion between the polypropylene resin substrate and other layers, for example. An easy-adhesion layer may be provided on the surface of the polypropylene resin substrate.

[0127] The polypropylene resin substrate may have a single-layer structure or a multi-layer structure. The thickness of the polypropylene resin substrate is preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. When the thickness is equal to or more than the lower limit, for example, the strength and heat resistance of the barrier laminate can be further improved. When the thickness is equal to or less than the upper limit, for example, the processability of the barrier laminate can be further improved.

[0128] The barrier laminate may have a printed layer on the surface of the polypropylene resin substrate. The image formed on the printed layer is not particularly limited, and may represent letters, patterns, symbols, or combinations thereof. The printed layer may also be formed using ink derived from biomass. This can further reduce the environmental load. The method for forming the printed layer is as described above.

[0129] <Sealant layer> The barrier laminate of the present disclosure includes a sealant layer. In one embodiment, the sealant layer contains a resin material that can be fused to each other by heat. Examples of the resin material that can be fused to each other by heat include polyolefins, specifically polyethylenes such as low-density polyethylene, linear low-density polyethylene, and medium-density polyethylene, polypropylene, polybutene, methylpentene polymers, and cyclic olefin copolymers.

[0130] Examples of resin materials that can be fused to each other by heat include ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-methyl(meth)acrylate copolymers, ethylene-ethyl(meth)acrylate copolymers, ethylene-vinyl alcohol copolymers, ionomer resins, acid-modified polyolefins obtained by modifying polyolefins with unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid, polyesters such as polyethylene terephthalate, polyvinyl acetate, polyvinyl chloride, and (meth)acrylic resins.

[0131] In one embodiment, the sealant layer is made of polypropylene. In this embodiment, the sealant layer is made of the same type of resin material as the polypropylene resin layer and the polypropylene resin substrate, i.e., polypropylene. This allows the packaging container to be made of a mono-material. After collecting used packaging containers, there is no need to separate the substrate and the sealant layer, improving the recyclability of the packaging container. By making the sealant layer of polypropylene, the oil resistance of the packaging container made using the barrier laminate can also be improved.

[0132] The content of polypropylene in the sealant layer is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, which can improve the recyclability of the packaging container, for example.

[0133] When the sealant layer is made of polypropylene, the content of polypropylene relative to the total amount of resin materials contained in the barrier laminate is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 88% by mass or more, and particularly preferably 90% by mass or more. This allows, for example, the production of a mono-material packaging container using the barrier laminate, thereby improving the recyclability of the packaging container.

[0134] Examples of polypropylene include propylene homopolymers, propylene random copolymers such as propylene-α-olefin random copolymers, and propylene block copolymers such as propylene-α-olefin block copolymers. Details of α-olefins are as described above. From the viewpoint of heat sealability, the density of polypropylene is, for example, 0.88 g / cm. 3 More than 0.92g / cm 3 The density is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C). From the viewpoint of reducing the environmental load, biomass-derived polypropylene and / or recycled polypropylene may be used. The sealant layer may contain the above-mentioned additives.

[0135] The sealant layer may have a single-layer structure or a multi-layer structure. The thickness of the sealant layer is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less. When the thickness is equal to or more than the lower limit, for example, the laminate strength of a packaging container provided with the barrier laminate can be further improved. When the thickness is equal to or less than the upper limit, for example, the processability of the barrier laminate can be further improved. When a pouch (particularly a retort pouch) is produced from the barrier laminate, the thickness of the sealant layer is more preferably 30 μm or more and 100 μm or less.

[0136] From the viewpoint of heat sealing property, the sealant layer is preferably an unstretched resin film, more preferably an unstretched polypropylene resin film. The resin film can be produced by, for example, a casting method, a T-die method, or an inflation method.

[0137] For example, an unstretched resin film corresponding to the sealant layer may be laminated on the second substrate via an adhesive layer as needed, or a resin material that can be fused to the second substrate by heat may be melt-extruded onto the second substrate to form the sealant layer. Examples of adhesive layers include the following:

[0138] <Adhesive layer> In one embodiment, the barrier laminate comprises an adhesive layer between the substrate and the sealant layer. In one embodiment, the barrier laminate comprises a first adhesive layer between the first substrate and the second substrate. In one embodiment, the barrier laminate comprises a second adhesive layer between the second substrate and the sealant layer. This can improve adhesion between the substrate and the sealant layer, adhesion between the first substrate and the second substrate, and / or adhesion between the second substrate and the sealant layer.

[0139] The adhesive layer is composed of an adhesive. The adhesive may be any of a one-component curing adhesive, a two-component curing adhesive, and a non-curing adhesive. The adhesive may be a solventless adhesive or a solvent-based adhesive. In one embodiment, the barrier laminate of the present disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer. This makes it possible to produce a laminate using an adhesive without directly applying an adhesive onto the vapor-deposited film, thereby suppressing deterioration of the vapor-deposited film.

[0140] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-component curing urethane adhesives are more preferred.

[0141] In one embodiment, the solventless adhesive is a two-component curing adhesive having a base agent and a curing agent. From the viewpoint of coatability, the weight-average molecular weight (Mw) of the polymer component contained in the base agent is preferably 800 or more and 10,000 or less, more preferably 1,200 or more and 4,000 or less. The polydispersity index (Mw / Mn) of the polymer component contained in the base agent is preferably 2.8 or less, more preferably 1.2 or more and 2.7 or less, even more preferably 1.5 or more and 2.6 or less, and particularly preferably 2.0 or more and 2.5 or less. Here, Mn is the number-average molecular weight of the polymer component contained in the base agent. Each average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 (2008) and is a value converted into polystyrene.

[0142] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives.

[0143] In one embodiment, by forming an adhesive layer using a solvent-free adhesive, for example, the amount of residual solvent in the barrier laminate, specifically the amount of residual organic solvent, can be further reduced. The barrier laminate of the present disclosure includes a polypropylene resin layer and a polypropylene resin substrate. Therefore, when producing the barrier laminate of the present disclosure using a solvent-based adhesive, the drying temperature needs to be lower than that of a polyester-based laminate to prevent deterioration and thermal shrinkage of the laminate. In this case, the solvent in the adhesive may not be sufficiently removed by volatilization and may remain in the barrier laminate, resulting in an odor due to the residual solvent. The use of a solvent-free adhesive can further reduce the amount of residual solvent.

[0144] Examples of the organic solvent include hydrocarbon solvents such as toluene, xylene, n-hexane, and methylcyclohexane; ester solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate; alcohol solvents such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; and ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0145] In one embodiment, the use of a solvent-free adhesive allows, for example, a thinner adhesive layer than when a solvent-based adhesive is used. This allows the polypropylene content in the entire barrier laminate to be further increased. Such a barrier laminate is suitable for producing mono-material packaging containers.

[0146] In one embodiment, the use of a solvent-free adhesive can improve the tearability of the barrier laminate, as will be described later, compared to the use of a solvent-based adhesive. The improved tearability is achieved by using a solvent-free adhesive, which allows the adhesive layer to be made thinner and harder.

[0147] The thickness of the adhesive layer is, for example, 0.1 μm to 10 μm, preferably 0.2 μm to 8 μm, and more preferably 0.5 μm to 6 μm. The thickness of the adhesive layer may be 2 μm or less.

[0148] In one embodiment, the barrier laminate of the present disclosure may be produced by bonding a first substrate, a second substrate, and a resin film corresponding to the sealant layer together by a non-solvent lamination method using a solvent-free adhesive, or by a dry lamination method using a solvent-based adhesive.

[0149] In one embodiment, the barrier laminate of the present disclosure comprises a first substrate, a first adhesive layer made of a solvent-free adhesive, a second substrate, a second adhesive layer made of a solvent-free adhesive, and a sealant layer.

[0150] A two-component curing urethane adhesive will be described below. As the urethane adhesive, for example, an adhesive having a base agent containing a polyol compound such as polyester polyol and a curing agent containing an isocyanate compound is preferable. Examples of polyol compounds include polyester polyols, polyether polyols, polycarbonate polyols, and (meth)acrylic polyols. Among these, polyester polyols are preferred.

[0151] Polyester polyols have two or more hydroxyl groups per molecule. The polyester polyols have, for example, a polyester structure or a polyester polyurethane structure as the main skeleton. The polyester polyols can be obtained, for example, by a dehydration condensation reaction, transesterification, or ring-opening reaction between a polyhydric alcohol component and a polycarboxylic acid component.

[0152] Examples of polyhydric alcohol components include diols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, and cyclohexanedimethanol; and tri- or higher functional polyols such as glycerin, triethylolpropane, trimethylolpropane, pentaerythritol, and sorbitol.

[0153] Examples of polycarboxylic acid components include aliphatic polycarboxylic acids, alicyclic polycarboxylic acids, and aromatic polycarboxylic acids, as well as their ester derivatives and acid anhydrides. Examples of aliphatic polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, and dimer acid. Examples of alicyclic polycarboxylic acids include 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid.

[0154] The polyester polyol may be pre-chain-lengthened with a polyisocyanate, if necessary. Examples of the polyisocyanate include diisocyanates such as 1,6-hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, m-xylylene diisocyanate, α,α,α'α'-tetramethyl-m-xylylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and diphenylmethane diisocyanate; and biuret, nurate, or trimethylolpropane adducts of diisocyanates.

[0155] From the viewpoint of coatability, the weight-average molecular weight (Mw) of the polyol compound such as polyester polyol is preferably 800 or more and 10,000 or less, more preferably 1,200 or more and 4,000 or less. The polydispersity index (Mw / Mn) of the polyol compound such as polyester polyol is preferably 2.8 or less, more preferably 1.2 or more and 2.7 or less, even more preferably 1.5 or more and 2.6 or less, and particularly preferably 2.0 or more and 2.5 or less. Here, Mn is the number-average molecular weight of the polyol compound. Each average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 (2008) and is a value converted into polystyrene.

[0156] The isocyanate compound has two or more isocyanate groups in one molecule. Examples of the isocyanate compound include aromatic isocyanates and aliphatic isocyanates. The isocyanate compound may be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known, conventional, appropriate method.

[0157] Examples of the isocyanate compound include diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, norbornene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, m-xylylene diisocyanate, hydrogenated xylylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and α,α,α'α'-tetramethyl-m-xylylene diisocyanate; trimers of these diisocyanates; and adducts, biurets, and allophanates obtained by reacting these diisocyanate compounds with low-molecular-weight active hydrogen compounds or alkylene oxide adducts thereof, or high-molecular-weight active hydrogen compounds.

[0158] Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexamethylene glycol, 1,8-octamethylene glycol, 1,4-cyclohexanedimethanol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine. Examples of high molecular weight active hydrogen compounds include polyesters, polyether polyols, and polyamides.

[0159] <Physical properties> In one embodiment, the barrier laminate of the present disclosure exhibits the following heat shrinkage percentage: MD direction refers to the machine direction of the laminate, and TD direction refers to the direction perpendicular to the MD direction.

[0160] The heat shrinkage rate in the MD direction (MD1) of the barrier laminate after heat treatment at 120°C for 15 minutes is, for example, 2.00% or less, preferably 1.20% or less, more preferably 1.00% or less, and even more preferably 0.90% or less. The lower limit of the heat shrinkage rate (MD1) is preferably as low as possible, but may be, for example, 0.10% or 0.20%. A barrier laminate with such a low heat shrinkage rate (MD1) has excellent gas barrier properties and is also excellent in bag-making suitability when producing packaging bags by heat sealing.

[0161] The thermal shrinkage rate (TD1) in the TD direction of the barrier laminate after heat treatment at 120°C for 15 minutes is, for example, 2.00% or less, preferably 1.50% or less, and more preferably 1.30% or less. The lower limit of the thermal shrinkage rate (TD1) is preferably as low as possible, but may be, for example, 0.10%, 0.20%, or 0.50%. A barrier laminate having such a low thermal shrinkage rate (TD1) as well as a low thermal shrinkage rate (MD1) has even better gas barrier properties and bag-making suitability. For example, it can suppress the occurrence of wrinkles and deformation in packaging bags produced by heat sealing. In particular, a low thermal shrinkage rate (TD1) can suppress image distortion in the printed layer of the barrier laminate.

[0162] The ratio (MD1 / TD1) of the thermal shrinkage rate (MD1) to the thermal shrinkage rate (TD1) of the barrier laminate after heat treatment at 120°C for 15 minutes is, for example, from 0.30 to 3.00, preferably from 0.35 to 2.00, and more preferably from 0.40 to 1.50. If the ratio (MD1 / TD1) is within this range, the laminate shrinks relatively uniformly in the MD and TD directions even after heat treatment, and therefore, for example, distortion of the image in the printed layer of the barrier laminate can be suppressed.

[0163] The thermal shrinkage (MD2) of the barrier laminate in the MD direction after heat treatment at 150°C for 5 minutes is, for example, 4.00% or less, preferably 3.50% or less, and more preferably 3.10% or less. The lower limit of the thermal shrinkage (MD2) is preferably as low as possible, but may be, for example, 0.50% or 1.00%.

[0164] The thermal shrinkage (TD2) in the TD direction of the barrier laminate after heat treatment at 150°C for 5 minutes is, for example, 4.00% or less, preferably 3.50% or less, and more preferably 2.80% or less. The lower limit of the thermal shrinkage (TD2) is preferably as low as possible, but may be, for example, 0.50% or 1.00%.

[0165] The ratio (MD2 / TD2) of the thermal shrinkage rate (MD2) to the thermal shrinkage rate (TD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is, for example, 0.30 or more and 3.00 or less, preferably 0.40 or more and 2.00 or less, and more preferably 0.50 or more and 1.60 or less.

[0166] Each heat shrinkage rate is calculated by the following formula. Heat shrinkage rate (MD) (%) = (length in MD direction of laminate before heat treatment - length in MD direction of laminate after heat treatment) / length in MD direction of laminate before heat treatment × 100 Heat shrinkage rate (TD) (%) = (length in the TD direction of the laminate before heat treatment - length in the TD direction of the laminate after heat treatment) / length in the TD direction of the laminate before heat treatment × 100

[0167] In one embodiment, the barrier laminate of the present disclosure exhibits the following tear strength. The tear strength is measured as follows. A sample is prepared by stacking 16 barrier laminates, alternating front and back, with the MD and TD directions of the films constituting the barrier laminate aligned. The tear strength of the sample in the MD and TD directions is measured in accordance with JIS K7128-2 (Elmendorf tear tester) using, for example, an Elmendorf tear tester No. 163 manufactured by Toyo Seiki Seisakusho, Ltd.

[0168] The tear strength (unit: N / 16 sheets) in the MD direction of the barrier laminate is, for example, 0.1 or more and 2.0 or less, and preferably 0.2 or more and 1.5 or less.

[0169] The barrier laminate has a tear strength in the TD direction (unit: N / 16 sheets) of, for example, 0.1 or more and 6.0 or less, preferably 0.2 or more and 5.5 or less, and more preferably 0.5 or more and 5.0 or less.

[0170] In one embodiment, the tear strength in the TD direction of the barrier laminate (unit: N / 16 sheets) is preferably 3.5 or less, more preferably 3.0 or less, and even more preferably 2.5 or less. This improves the openability in the TD direction of a packaging container made of the barrier laminate. For example, by using a solventless adhesive when producing the barrier laminate, the tear strength in the TD direction can be further reduced.

[0171] The ratio of the tear strength in the TD direction to the tear strength in the MD direction of the barrier laminate (strength TD / strength MD ) is, for example, 8.0 or less, preferably 7.0 or less, and more preferably 6.0 or less. The lower limit of the above ratio is not particularly limited, but may be, for example, 1.0, 1.5, or 2.0.

[0172] In one embodiment, the ratio (intensity TD / strength MD ) is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. This can improve the openability in the TD direction of a packaging container made of the barrier laminate.

[0173] In one embodiment, the amount of residual solvent in the barrier laminate of the present disclosure is 30 mg / m 2 or less, preferably 10 mg / m 2 Less than 5 mg / m, more preferably 2 or less, more preferably 3 mg / m 2 Below, 2mg / m 2 or less than 1 mg / m 2 The lower limit of the residual solvent amount is preferably as small as possible, for example, 0.1 mg / m 2 or 0.2 mg / m 2 That's fine too.

[0174] The amount of residual solvent can be measured by cutting a 10 cm square sample from the barrier laminate and measuring the sample by a calibration curve method using, for example, a gas chromatograph GC-2014 manufactured by Shimadzu Corporation.

[0175] [Packaging container] The barrier laminate of the present disclosure can be suitably used for packaging material applications. The packaging material is used to produce a packaging container. The packaging material comprises the barrier laminate of the present disclosure. The packaging container can be produced by using at least the packaging material comprising the barrier laminate of the present disclosure.

[0176] The packaging container of the present disclosure includes the barrier laminate (hereinafter also simply referred to as "laminate") of the present disclosure. Examples of packaging containers include packaging bags, tube containers, and containers with lids. The containers with lids include a container body having a storage section and a lid material joined (heat sealed) to the container body so as to seal the storage section.

[0177] In one embodiment, the packaging container of the present disclosure maintains gas barrier properties even when subjected to high-temperature treatment and exhibits minimal deformation, making it suitable as a microwave oven container or a boiling or retort container. The packaging container of the present disclosure is also suitable as a microwave boiling or retort container. The packaging container of the present disclosure is particularly suitable as a boiling or retort pouch.

[0178] Examples of heat sealing methods include bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing.

[0179] Examples of packaging bags include various types of packaging bags such as a standing pouch type, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a palm seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type.

[0180] The packaging container may have an easy-to-open portion. Examples of the easy-to-open portion include a notch portion that serves as a starting point for tearing the packaging container, and a half-cut line formed by laser processing or a cutter as a path for tearing the packaging container.

[0181] The packaging container may include a steam release mechanism that is configured to communicate the inside and outside of the packaging container when the steam pressure inside the packaging container reaches or exceeds a predetermined value, thereby allowing the steam to escape and preventing the steam from escaping at locations other than the steam release mechanism.

[0182] The steam release mechanism includes, for example, a steam release seal portion that protrudes from the side seal portion toward the inside of the packaging container, and an unsealed portion that is isolated from the content storage portion by the steam release seal portion. The unsealed portion is in communication with the outside of the packaging container. The packaging container is filled with content and the opening is heat-sealed, and is heated using a microwave oven or the like. This increases the internal pressure, causing the steam release seal portion to peel. Steam passes through the peeled portion of the steam release seal portion and the unsealed portion and escapes to the outside of the packaging container.

[0183] In one embodiment, a packaging bag can be produced by folding the laminate of the present disclosure in half and overlapping it so that the first substrate is on the outside and the sealant layer is on the inside, and then heat-sealing the edges, etc. In another embodiment, a packaging bag can be produced by overlapping multiple laminates of the present disclosure so that the sealant layers face each other, and then heat-sealing the edges, etc. The entire packaging bag may be made of the above-mentioned laminate, or only a portion of the packaging bag may be made of the above-mentioned laminate.

[0184] In one embodiment, the laminate of the present disclosure is used as a lid material in a lidded container. The lidded container comprises a container body having a storage section and a lid material joined (heat sealed) to the container body so as to seal the storage section. Here, the lid material, i.e., the sealant layer of the laminate, and the container body are heat sealed. Examples of the shape of the container body include a cup shape and a cylindrical shape with a bottom. The container body is made of, for example, polystyrene, polypropylene, polyethylene, or paper.

[0185] The contents to be contained in the packaging container include, for example, liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, and pharmaceuticals. After the contents are contained in the packaging container, the opening of the packaging container can be heat-sealed to seal the packaging container.

[0186] As specific examples of packaging bags, small pouches and standing pouches will be described below. A sachet is a small packaging bag used to hold contents of, for example, 1 g to 200 g, such as sauces, soy sauce, dressings, ketchup, syrup, cooking alcohol, other liquid or viscous seasonings, liquid soups, powdered soups, fruit juices, spices, liquid beverages, jelly-like beverages, instant foods, and other foods and beverages.

[0187] Stand-up pouches are used to store contents of, for example, 50 g to 2000 g, including shampoo, rinse, conditioner, hand soap, body soap, air freshener, deodorant, insect repellent, detergent, dressing, cooking oil, mayonnaise, other liquid or viscous seasonings, liquid beverages, jelly-like beverages, instant foods, other foods and beverages, and creams.

[0188] 13 shows a packaging bag 50 obtained by bonding two laminates together. The shaded areas indicate the heat-sealed areas. The packaging bag 50 may have an easy-to-open portion 51. Examples of the easy-to-open portion 51 include a notch portion 52 that serves as a tearing starting point and a half-cut line 53 formed by laser processing or a cutter as a tearing path.

[0189] FIG. 14 shows a simplified example of the configuration of a stand-up pouch. The shaded areas indicate the heat-sealed areas. In one embodiment, a stand-up pouch 60 comprises a body portion (side sheets) 61 and a bottom portion (bottom sheet) 62. The side sheets 61 and the bottom sheet 62 may be made of the same material, or may be made of different materials. The bottom sheet 62 maintains the shape of the side sheets 61, thereby imparting self-supporting properties to the pouch and enabling it to become a standing pouch. A storage space for storing contents is formed within the area surrounded by the side sheets 61 and the bottom sheet 62.

[0190] The standing pouch 60 may be provided with a steam release mechanism 63. The steam release mechanism 63 includes a steam release seal portion 63a that protrudes from the side seal portion toward the inside of the packaging container, and a non-sealed portion 63b that is isolated from the content-accommodating portion by the steam release seal portion 63a. The non-sealed portion 63b communicates with the outside of the packaging container.

[0191] In a stand-up pouch, only the body portion may be made of the laminate of the present disclosure, only the bottom portion may be made of the laminate of the present disclosure, or both the body portion and the bottom portion may be made of the laminate of the present disclosure.

[0192] In one embodiment, the side sheet can be formed by making a bag so that the sealant layer of the laminate of the present disclosure is the innermost layer. In one embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them with the sealant layers facing each other, and heat-sealing both side edges to form a bag.

[0193] In another embodiment, the side sheets can be formed by preparing two laminates of the present disclosure, overlapping them with the sealant layers facing each other, inserting two V-shaped laminates with the sealant layers facing outward between the laminates at the side edges on both sides of the overlapped laminates, and heat-sealing the laminates. This production method produces a stand-up pouch having a body with side gussets.

[0194] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower portions of the side sheets of a bag and heat sealing them. More specifically, the bottom sheet can be formed by inserting the laminate folded in a V shape with the sealant layer facing outward between the lower portions of the side sheets of a bag and heat sealing them.

[0195] In one embodiment, two of the above laminates are prepared and stacked together with the sealant layers facing each other. Then, another of the above laminates is folded in a V shape with the sealant layer facing outward, and this is sandwiched between the two laminates and heat-sealed to form a bottom. Next, two sides adjacent to the bottom are heat-sealed to form a body. In this manner, a standing pouch according to one embodiment can be formed.

[0196] The present disclosure relates to, for example, the following [1] to

[18] . [1] A barrier laminate comprising a substrate and a sealant layer in this order in the thickness direction, wherein the substrate is a barrier substrate comprising a polypropylene resin layer and a vapor-deposited film, the polypropylene resin layer is a layer that has been subjected to a stretching treatment, and the vapor-deposited film is made of an inorganic oxide, and wherein after heat treatment at 120°C for 15 minutes, the barrier laminate has a thermal shrinkage rate in the MD direction (MD1) of 2.00% or less and a thermal shrinkage rate in the TD direction (TD1) of 2.00% or less. [2] The barrier laminate according to [1] above, which comprises a first substrate, a second substrate, and a sealant layer in this order in the thickness direction, one of the first substrate and the second substrate being a barrier substrate, and the other of the first substrate and the second substrate being a polypropylene resin substrate that has been subjected to a stretching treatment. [3] The barrier laminate according to the above [1] or [2], wherein the ratio (MD1 / TD1) of the heat shrinkage rate (MD1) to the heat shrinkage rate (TD1) of the barrier laminate after heat treatment at 120°C for 15 minutes is 0.30 or more and 3.00 or less. [4] The barrier laminate according to any one of the above [1] to [3], wherein the barrier laminate has a heat shrinkage rate in the MD direction (MD2) of 4.00% or less and a heat shrinkage rate in the TD direction (TD2) of 4.00% or less after heat treatment at 150°C for 5 minutes. [5] The barrier laminate according to the above item [4], wherein the ratio (MD2 / TD2) of the heat shrinkage rate (MD2) to the heat shrinkage rate (TD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is 0.30 or more and 3.00 or less. [6] The barrier laminate according to the above item [2], wherein, when the first substrate is a barrier substrate, the first substrate is arranged so that the vapor-deposited film faces the sealant layer side and the polypropylene resin layer faces the side opposite to the sealant layer, and when the second substrate is a barrier substrate, the second substrate is arranged so that the vapor-deposited film faces the first substrate side and the polypropylene resin layer faces the sealant layer side. [7] The barrier laminate according to the above [2] or [6], wherein the first substrate is a polypropylene resin substrate and the second substrate is a barrier substrate. [8] The barrier laminate according to any one of the above [1] to [7], wherein the barrier substrate further comprises a surface coating layer between the polypropylene resin layer and the vapor-deposited film, and the surface coating layer contains a resin material having a polar group. [9] The barrier laminate according to any one of the above [1] to [7], wherein the barrier substrate further comprises a surface resin layer between the polypropylene resin layer and the vapor-deposited film, and the surface resin layer contains a resin material having a melting point of 180°C or higher.

[10] The barrier laminate according to the above [9], wherein the polypropylene resin layer and the surface resin layer in the barrier substrate are co-extruded stretched resin films.

[11] The barrier laminate according to any one of the above [1] to

[10] , further comprising a barrier coat layer on the vapor-deposited film.

[12] The barrier laminate according to any one of the above [1] to

[11] , wherein the sealant layer is a resin layer made of polypropylene.

[13] The barrier laminate according to the above item [2], [6] or [7], further comprising a first adhesive layer between the first substrate and the second substrate, and a second adhesive layer between the second substrate and the sealant layer.

[14] The barrier laminate according to any one of the above [1] to

[13] , which is used for packaging container applications.

[15] A packaging container comprising the barrier laminate according to any one of the above [1] to

[14] .

[16] The packaging container according to

[15] above, which is a boilable or retort pouch.

[17] A lid material comprising the barrier laminate according to any one of the above [1] to

[14] .

[18] A packaging container comprising a container body having a storage section and the lid material according to

[17] above joined to the container body so as to seal the storage section. [Example]

[0197] The barrier laminate of the present disclosure will be specifically described below based on examples.

[0198] [Preparation of barrier substrate] A hydroxyl group-containing (meth)acrylic resin (number average molecular weight: 25,000, glass transition temperature: 99°C, hydroxyl value: 80 mgKOH / g) was diluted with a mixed solvent of methyl ketone and ethyl acetate (mixing ratio 1:1) to a solids concentration of 10 mass % to prepare the base resin.

[0199] An ethyl acetate solution containing tolylene diisocyanate (solid content 75% by mass) was added to the base resin as a curing agent to obtain a solution for forming a surface coating layer. The amount of the curing agent used was 10 parts by mass per 100 parts by mass of the base resin.

[0200] A 20 μm-thick biaxially stretched polypropylene film (ME-1, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) was prepared, one side of which was corona-treated. The solution for forming a surface coating layer was applied to the corona-treated surface of the film and dried to form a surface coating layer with a thickness of 0.5 μm, thereby obtaining a resin substrate.

[0201] A carbon-containing silicon oxide vapor deposition film with a thickness of 12 nm was formed on the surface coating layer of the resin substrate using a low-temperature plasma chemical vapor deposition apparatus (CVD method) in a roll-to-roll manner while applying tension to the resin substrate. The deposition film formation conditions were as follows:

[0202] (Formation conditions) Hexamethyldisiloxane: oxygen gas: helium = 1:10:10 (unit: slm) Cooling / electrode drum power supply: 22kW Line speed: 100m / min

[0203] The carbon percentage C, silicon percentage Si, and oxygen percentage O in the carbon-containing silicon oxide vapor-deposited film were measured. The carbon percentage C, silicon percentage Si, and oxygen percentage O were 32.7%, 29.8%, and 37.5%, respectively, based on 100% as the total of the three elements silicon, oxygen, and carbon. The percentages of each element were measured by narrow scan analysis using X-ray photoelectron spectroscopy (XPS) under the measurement conditions described above.

[0204] 385 g of water, 67 g of isopropyl alcohol, and 9.1 g of 0.5 N hydrochloric acid were mixed to obtain a solution with a pH of 2.2. 175 g of tetraethoxysilane as a metal alkoxide and 9.2 g of glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed with this solution while cooling to 10°C to obtain Solution A.

[0205] Solution B was obtained by mixing 14.7 g of polyvinyl alcohol as a water-soluble polymer having a saponification degree of 99% or more and a polymerization degree of 2400, 324 g of water, and 17 g of isopropyl alcohol.

[0206] A barrier coating agent was obtained by mixing Solution A and Solution B in a mass ratio of 6.5:3.5. The barrier coating agent was coated onto a vapor-deposited film formed on a resin substrate by spin coating, and then heated in an oven at 80°C for 60 seconds to form a barrier coating layer with a thickness of 300 nm. In this manner, a transparent barrier substrate was obtained.

[0207] [Example 1] The biaxially oriented polypropylene film surface of the transparent barrier substrate was subjected to a corona treatment to set the wet tension to 38 dyn or more. A 20 μm-thick biaxially oriented polypropylene film (P2171, manufactured by Toyobo Co., Ltd.) was used as the first substrate, and the corona-treated transparent barrier substrate was used as the second substrate. A 60 μm-thick unstretched polypropylene film (ZK207, manufactured by Toray Advanced Film Co., Ltd.) was dry-laminated as a sealant layer using a polyester urethane adhesive (RU-004 / H-1, manufactured by Rock Paint Co., Ltd., blending ratio 7.5 / 1). The resulting laminate was left to stand at 40°C for 72 hours to obtain a barrier laminate. The thickness of the adhesive layer formed by the polyester urethane adhesive was 4 μm. The polypropylene content in the barrier laminate was 89% by mass.

[0208] A 10 cm square sample was cut out from the obtained barrier laminate. The residual solvent amount of the sample was measured by a calibration curve method using a gas chromatograph GC-2014 manufactured by Shimadzu Corporation. The residual solvent amount was 20 mg / m 2 It was.

[0209] Sixteen sheets of the obtained barrier laminate were stacked alternately, front and back, with the MD and TD directions of the films constituting the barrier laminate aligned to prepare a sample. The tear strength of the sample in the MD and TD directions was measured in accordance with JIS K7128-2 (Elmendorf tear test) using a No. 163 Elmendorf tear tester manufactured by Toyo Seiki Seisaku-sho, Ltd. The results showed that the tear strength in the MD direction was 0.7 N / 16 sheets, and the tear strength in the TD direction was 4.1 N / 16 sheets, and the tear strength ratio (strength TD / strength MD ) was 5.9.

[0210] Example 1a The biaxially oriented polypropylene film surface of the transparent barrier substrate was subjected to a corona treatment to set the wet tension to 38 dyn or more. A 20 μm-thick biaxially oriented polypropylene film (P2171, manufactured by Toyobo Co., Ltd.) was used as the first substrate, and the corona-treated transparent barrier substrate was used as the second substrate. A 60 μm-thick unstretched polypropylene film (ZK207, manufactured by Toray Advanced Film Co., Ltd.) was used as the sealant layer. These were then non-solvent laminated together using a polyester urethane adhesive (RN-920 / HN-920 (blending ratio 1 / 1) manufactured by Rock Paint Co., Ltd.). The resulting laminate was left at 40°C for 72 hours to obtain a barrier laminate. The thickness of the adhesive layer formed by the polyester urethane adhesive was 1 μm. The polypropylene content in the barrier laminate was 95% by mass.

[0211] The amount of residual solvent in the obtained barrier laminate was 0.7 mg / m 2 It was. Sixteen sheets of the obtained barrier laminate were stacked alternately front and back so that the MD and TD directions of the films constituting the barrier laminate were aligned to prepare a sample. The tear strength of the sample in the MD direction was 0.6 N / 16 sheets, and the tear strength in the TD direction was 1.7 N / 16 sheets. TD / strength MD ) was 2.8.

[0212] [Example 2] The transparent barrier substrate was used as the first substrate, a 20 μm-thick biaxially oriented polypropylene film (P2271, manufactured by Toyobo Co., Ltd.) was used as the second substrate, and a 60 μm-thick unoriented polypropylene film (ZK207, manufactured by Toray Advanced Film Co., Ltd.) was used as the sealant layer. These were dry-laminated together using a polyester urethane adhesive (RU-004 / H-1, manufactured by Rock Paint Co., Ltd., blending ratio 7.5 / 1) and allowed to stand at 40°C for 72 hours to obtain a barrier laminate. The adhesive layer formed by the polyester urethane adhesive had a thickness of 4 μm. The polypropylene content in the barrier laminate was 89% by mass.

[0213] [Gas barrier property evaluation] The barrier laminate obtained above was cut out to obtain a test piece. The test piece was used to measure the oxygen permeability (cc / m 2 ·day·atm) and water vapor permeability (g / m 2 ·day) was measured by the following method.

[0214] Using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON), the test piece was set so that the first substrate side was the oxygen supply side, and the oxygen permeability was measured in an environment of 23°C and a relative humidity of 90% RH in accordance with JIS K 7126.

[0215] Using a water vapor permeability measuring device (MOCON, PERMATRAN-w 3 / 33), the test piece was set so that the first substrate side was the water vapor supply side, and the water vapor permeability was measured in an environment of 40°C and a relative humidity of 90% RH in accordance with JIS K 7129.

[0216] [Gas barrier property evaluation (after boiling or retort processing)] A flat packaging bag was produced using the barrier laminate obtained above. The size of the flat packaging bag was B5 size (182 mm × 257 mm). The flat packaging bag was filled with 150 mL of water.

[0217] A flat packaging bag was boiled in hot water at 95°C for 30 minutes. A barrier laminate was cut out from the flat packaging bag to obtain a test piece. The oxygen permeability and water vapor permeability of this test piece were measured in the same manner as described above.

[0218] The flat packaging bag was retorted in hot water at 121°C for 30 minutes. A barrier laminate was cut out from the flat packaging bag to obtain a test piece. The oxygen permeability and water vapor permeability of this test piece were measured in the same manner as described above.

[0219] [Gas barrier property evaluation (after Gelboflex test)] Two sheets of the barrier laminate obtained above were used to prepare a four-sided bag. The size of this bag was A4 size (210 mm × 297 mm). Using this bag, a Gelbo flex test (stroke: 80 mm, bending motion: 400°) in accordance with ASTM F392 was repeated 10 times. Then, a barrier laminate was cut out from the bag to obtain a test piece. Using this test piece, the oxygen permeability and water vapor permeability were measured in the same manner as above.

[0220] [Gas barrier property evaluation (after boiling or retort processing and Gelbo Flex test)] Two sheets of the barrier laminate obtained above were used to prepare a square bag. The size of this bag was A4 size (210 mm x 297 mm). 400 mL of water was filled inside the bag. The square bag was subjected to boiling or retort treatment under the above conditions. The water was removed from the square bag, and the bag was used to perform a Gelbo Flex test (stroke: 80 mm, bending motion: 400°) in accordance with ASTM F392 10 times. A barrier laminate was then cut out from the bag to obtain a test piece. The oxygen permeability and water vapor permeability of this test piece were measured in the same manner as above.

[0221] [Measurement of heat shrinkage rate] The barrier laminate obtained above was cut into a size of 10 cm x 10 cm to obtain a test piece. The test piece was placed in an oven and heated at 120°C for 15 minutes or at 150°C for 5 minutes. The lengths of the test piece in the MD and TD directions were measured using a glass scale before and after heating in the oven. The heat shrinkage in the MD direction (MD) and the heat shrinkage in the TD direction (TD) were calculated using the following formula. Table 1 shows the average heat shrinkage for the two test pieces.

[0222] Heat shrinkage rate (MD) (%) = (length in MD direction of laminate before heat treatment - length in MD direction of laminate after heat treatment) / length in MD direction of laminate before heat treatment × 100 Heat shrinkage rate (TD) (%) = (length in the TD direction of the laminate before heat treatment - length in the TD direction of the laminate after heat treatment) / length in the TD direction of the laminate before heat treatment × 100

[0223] [Table 1] [Explanation of symbols]

[0224] 1: Barrier laminate, 10: Polypropylene resin substrate, 20: Barrier substrate, 22: Polypropylene resin layer, 23: Surface coating layer or surface resin layer, 24: Vapor deposition film, 25: Barrier coating layer, 30: Sealant layer, 40A, 40B: Adhesive layers, 50: packaging bag, 51: easy-to-open portion, 52: notch portion, 53: half-cut line, 60: Standing pouch, 61: Body (side sheet), 62: Bottom (bottom sheet), 63: Steam release mechanism, 63a: Steam release seal part, 63b: Non-seal part, A: vacuum vessel, B: unwinding section, C: film-forming drum, D: winding section, E: transport roll, F: evaporation source, G: reactive gas supply section, H: protective box, I: evaporation material, J: plasma gun, S: substrate, A1: vacuum vessel, B1: unwinding section, C1: cooling / electrode drum, D1: winding section, E1: transport roll, F1: glow discharge plasma, G1: reactive gas supply section, H1: raw material supply nozzle, I1: raw material gas supply section, J1: magnet, K1: power supply, L1: vacuum pump

Claims

1. A barrier laminate comprising a substrate and a sealant layer in this order in a thickness direction, the substrate is a barrier substrate comprising a polypropylene resin layer and a vapor-deposited film, the polypropylene resin layer is a layer that has been subjected to a stretching treatment, the vapor-deposited film is made of an inorganic oxide, A barrier laminate, wherein after heat treatment at 120°C for 15 minutes, the barrier laminate has a heat shrinkage rate in the MD direction (MD1) of 2.00% or less and a heat shrinkage rate in the TD direction (TD1) of 2.00% or less.

2. the barrier laminate comprises a first substrate, a second substrate, and the sealant layer in this order in a thickness direction; one of the first substrate and the second substrate is the barrier substrate, and the other of the first substrate and the second substrate is a polypropylene resin substrate; The polypropylene resin substrate is a substrate that has been subjected to a stretching treatment. The barrier laminate according to claim 1 .

3. 3. The barrier laminate according to claim 1 or 2, wherein the ratio (MD1 / TD1) of the heat shrinkage rate (MD1) to the heat shrinkage rate (TD1) of the barrier laminate after heat treatment at 120°C for 15 minutes is 0.30 or more and 3.00 or less.

4. 4. The barrier laminate according to claim 1, wherein after heat treatment at 150°C for 5 minutes, the barrier laminate has a heat shrinkage rate in the machine direction (MD2) of 4.00% or less and a heat shrinkage rate in the transverse direction (TD2) of 4.00% or less.

5. 5. The barrier laminate according to claim 4, wherein the ratio (MD2 / TD2) of the heat shrinkage rate (MD2) to the heat shrinkage rate (TD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is 0.30 or more and 3.00 or less.

6. When the first substrate is the barrier substrate, the first substrate is disposed so that the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces the side opposite to the sealant layer; When the second substrate is the barrier substrate, the second substrate is disposed so that the vapor-deposited film faces the first substrate side and the polypropylene resin layer faces the sealant layer side. The barrier laminate according to claim 2 .

7. the first substrate is the polypropylene resin substrate, the second substrate is the barrier substrate; The barrier laminate according to claim 2 or 6.

8. 8. The barrier laminate according to claim 1, wherein the barrier substrate further comprises a surface coating layer between the polypropylene resin layer and the vapor-deposited film, and the surface coating layer contains a resin material having a polar group.

9. 8. The barrier laminate according to claim 1, wherein the barrier substrate further comprises a surface resin layer between the polypropylene resin layer and the vapor-deposited film, and the surface resin layer contains a resin material having a melting point of 180°C or higher.

10. 10. The barrier laminate according to claim 9, wherein the polypropylene resin layer and the surface resin layer in the barrier substrate are co-extruded stretched resin films.

11. The barrier laminate according to any one of claims 1 to 10, further comprising a barrier coat layer on the vapor-deposited film.

12. The barrier laminate according to any one of claims 1 to 11, wherein the sealant layer is a resin layer made of polypropylene.

13. a first adhesive layer between the first substrate and the second substrate; a second adhesive layer is provided between the second substrate and the sealant layer; The barrier laminate according to claim 2, 6 or 7.

14. The barrier laminate according to any one of claims 1 to 13, which is used for packaging container applications.

15. A packaging container comprising the barrier laminate according to any one of claims 1 to 14.

16. 16. The packaging container according to claim 15, which is a boil or retort pouch.

17. A lid material comprising the barrier laminate according to any one of claims 1 to 14.

18. A packaging container comprising: a container body having a storage portion; and the lid member according to claim 17 joined to the container body so as to seal the storage portion.

Images