Barrier laminates, lids, and packaging containers

Abstract

The gas barrier properties of a laminate having a barrier substrate with a vapor-deposited film formed on a stretched polypropylene film and a sealant layer are improved. [Solution] A barrier laminate comprising a first substrate, a second substrate, and a sealant layer in this order in the thickness direction, wherein 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 or the second substrate is a polypropylene resin substrate, the polypropylene resin layer is a stretched layer, the vapor-deposited film is composed of an inorganic oxide, and the polypropylene resin substrate is a stretched substrate.

Description

[Technical Field]

[0001] This disclosure relates to barrier laminates, lid materials, and packaging containers. [Background technology]

[0002] Polyester films, such as polyethylene terephthalate, possess excellent mechanical properties, chemical stability, heat resistance, and transparency, while also being inexpensive. Therefore, polyester films have traditionally been used as a base material for laminates used in the manufacture of packaging containers.

[0003] Depending on the contents filled in the packaging container, gas barrier properties such as oxygen barrier and water vapor barrier are required. To meet this requirement, a vapor-deposited film containing alumina or silica is formed on the surface of the polyester film (see, for example, Patent Document 1). In recent years, alternative substrates to polyester film have been sought. Polyolefin film, particularly polypropylene film, is being considered as the above-mentioned substrate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-053223 [Overview of the Initiative] [Problems that the invention aims to solve]

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

[0006] One of the problems to be solved by the present disclosure is to improve the gas barrier property of a laminate having a barrier base material on which a vapor deposition 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 includes a first base material, a second base material, and a sealant layer in this order in the thickness direction. Either one of the first base material and the second base material is a barrier base material including a polypropylene resin layer and a vapor deposition film, and the other of the first base material and the second base material is a polypropylene resin base material. The polypropylene resin layer is a layer subjected to a stretching treatment. The vapor deposition film is composed of an inorganic oxide. The polypropylene resin base material is a base material subjected to a stretching treatment.

Advantages of the Invention

[0008] According to the present disclosure, the gas barrier property of a laminate having a barrier base material on which a vapor deposition film is formed on a stretched polypropylene film and a sealant layer can be improved.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an embodiment of the barrier laminate. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an embodiment of the vapor deposition apparatus. [Figure 8]FIG. 8 is a schematic cross-sectional view showing an embodiment of a vapor deposition apparatus. [Figure 9] FIG. 9 is a schematic cross-sectional view showing another embodiment of the vapor deposition apparatus. [Figure 10] FIG. 10 is a front view showing an embodiment of a packaging container. [Figure 11] FIG. 11 is a perspective view showing an embodiment of the packaging container.

MODE FOR CARRYING OUT 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 is not to be construed as limited to the description of the embodiments exemplified below. The drawings may schematically represent the width, thickness, shape, etc. of each layer compared to the embodiments for the sake of clearer explanation, but are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements that are the same as those already described with respect to the previously presented drawings may be denoted by the same reference numerals, and detailed description may be appropriately omitted.

[0011] In the following description, each component that appears (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 a first base material, a second base material, and a sealant layer are provided in this order in the thickness direction.

[0013] 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 or the second substrate is a stretched polypropylene resin substrate. In this embodiment, either the first substrate or the second substrate is a barrier substrate, and the other of the first substrate or the second substrate is a polypropylene resin substrate; however, in other embodiments, either the first substrate or the second substrate may be a barrier substrate. The polypropylene resin layer has been stretched. The deposited film is composed of inorganic oxides.

[0014] Figures 1 to 6 are schematic cross-sectional views showing one embodiment of a barrier laminate. The barrier laminate 1 shown in Figure 1 comprises 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, in this order in the thickness direction. The barrier substrate 20 comprises 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.

[0015] Figure 2 is the same as Figure 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.

[0016] Figure 3 is the same as in Figure 1, except that the barrier substrate 20 comprises a polypropylene resin layer 22, a surface coating layer or surface resin layer 23, a vapor-deposited film 24, and a barrier coating layer 25 in this order in the thickness direction. In this example, the barrier coating layer 25 is in contact with the adhesive layer 40A.

[0017] The barrier laminate 1 shown in Figure 4 comprises 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, in this order in the thickness direction. The barrier substrate 20 comprises 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.

[0018] Figure 5 is the same as in Figure 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.

[0019] Figure 6 is the same as in Figure 4, except that the barrier substrate 20 comprises a polypropylene resin layer 22, a surface coating layer or surface resin layer 23, a vapor-deposited film 24, and a barrier coating layer 25 in this order in the thickness direction. In this example, the barrier coating layer 25 is in contact with the adhesive layer 40A.

[0020] In one embodiment, the barrier laminate of this disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer. Compared to a laminate comprising only two elements, a barrier substrate and a sealant layer, the barrier laminate of this disclosure exhibits superior gas barrier properties (particularly oxygen barrier properties and water vapor barrier properties). This is more clearly evident in the case of the barrier laminate after heat treatment and / or Gelboflex testing. Furthermore, the barrier laminate of this disclosure has a low thermal shrinkage rate when subjected to heat treatment, and therefore has excellent suitability for bag making.

[0021] In one embodiment, when the first substrate is a barrier substrate, the first substrate is arranged such that the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces away from the sealant layer. When the second substrate is a barrier substrate, in one embodiment, the second substrate is arranged such that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer, or the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces the first substrate. Among these, from the viewpoint of further suppressing the deterioration of the vapor-deposited film, when the second substrate is a barrier substrate, it is preferable that the second substrate is arranged such that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer.

[0022] In one embodiment, the barrier laminate of the present disclosure has a first substrate which is a polypropylene resin substrate and a second substrate which is a barrier substrate (see Figures 1 to 3). 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 with this configuration has a vapor-deposited film that is properly protected when subjected to heat treatment, and exhibits even higher gas barrier properties. Furthermore, the barrier laminate of the above embodiment has a smaller thermal shrinkage rate when subjected to heat treatment, and therefore has even better suitability for bag making.

[0023] In this disclosure, the phrase "AAA composed of polypropylene" means that the main component of the AAA is polypropylene, but the AAA is not limited to being composed solely of polypropylene. The AAA may contain other components besides 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.

[0024] <Polypropylene resin base material> The polypropylene resin substrate constitutes either the first substrate or the second substrate. The polypropylene resin substrate is made of polypropylene. By having a barrier laminate that includes a substrate made of polypropylene, for example, the oil resistance of packaging containers made using the barrier laminate can be improved.

[0025] Polypropylene may be a homopolymer, a random copolymer, or a block copolymer, or a mixture of two or more selected from these.

[0026] A propylene homopolymer is a polymer composed solely of propylene. A propylene random copolymer is a random copolymer of propylene and α-olefins other than propylene. A propylene block copolymer is a copolymer having polymer blocks made of propylene and polymer blocks made of α-olefins other than propylene.

[0027] Examples of α-olefins include α-olefins having 2 to 20 carbon atoms, specifically 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.

[0028] Among polypropylenes, homopolymers or random copolymers are preferable from the viewpoint of transparency. When rigidity and heat resistance of the packaging container are important, homopolymers are preferable. When impact resistance of the packaging container is important, random copolymers are preferable.

[0029] The melt flow rate (MFR) of polypropylene may, in one embodiment, be 0.1 g / 10 min to 50 g / 10 min or 0.3 g / 10 min to 30 g / 10 min, from the viewpoint of film-forming properties and processability. The MFR of polypropylene is measured in accordance with ASTM D1238, under conditions of a temperature of 230°C and a load of 2.16 kg.

[0030] As for the polypropylene, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used.

[0031] 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 even more preferably 95% by mass or more.

[0032] The polypropylene resin substrate may contain resin materials other than polypropylene. Examples of resin materials include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

[0033] Polypropylene resin substrates may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0034] The polypropylene resin substrate is a substrate that has undergone 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 substrate is suitable as a packaging material for packaging containers that undergo boiling or retorting treatment, for example. The stretching process can be either uniaxial stretching or biaxial stretching.

[0035] When stretching in the longitudinal direction (the direction of substrate flow, MD direction), the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less. 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 also be improved. From the viewpoint of the breaking limit of the polypropylene resin substrate, a stretching ratio of 15 times or less is preferable.

[0036] In one embodiment, the polypropylene resin substrate may be surface-treated. This can improve, for example, the adhesion between the polypropylene resin substrate 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 substrate.

[0037] 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 to 100 μm, more preferably 10 μm to 50 μm. If the thickness is above the lower limit, for example, the strength and heat resistance of the barrier laminate can be further improved. If the thickness is below the upper limit, for example, the processability of the barrier laminate can be further improved.

[0038] The barrier laminate may have a printed layer on the surface of a polypropylene resin substrate. The image formed on the printed layer is not particularly limited and may represent characters, patterns, symbols, or combinations thereof. The printed layer can also be formed using biomass-derived ink. This further reduces the environmental impact.

[0039] Conventional printing methods such as gravure printing, offset printing, and flexographic printing can be used to form the printed layer. Among these, flexographic printing is preferred from the viewpoint of reducing environmental impact.

[0040] <Barrier substrate> The barrier substrate constitutes either the first substrate or the second substrate. When the polypropylene resin substrate is the first substrate, the barrier substrate is the second substrate. When the polypropylene resin substrate is the second substrate, the barrier substrate is the first substrate. In this embodiment, the barrier substrate is used as either the first substrate or the second substrate, and the polypropylene resin substrate is used as the other of the first and second substrates. However, in other embodiments, both the first and second substrates may be barrier substrates.

[0041] 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 have a surface coating layer or a surface resin layer between the polypropylene resin layer and the vapor-deposited film. The barrier substrate may have a barrier coating layer on the vapor-deposited film.

[0042] (Polypropylene resin layer) The polypropylene resin layer is made of polypropylene. By including a layer made of polypropylene in the barrier substrate, for example, the oil resistance of packaging containers made using the barrier substrate can be improved.

[0043] Polypropylene may be a homopolymer, a random copolymer, or a block copolymer, or a mixture of two or more selected from these. Details are as described above.

[0044] Among polypropylenes, homopolymers or random copolymers are preferable from the viewpoint of transparency. When rigidity and heat resistance of the packaging container are important, homopolymers are preferable. When impact resistance of the packaging container is important, random copolymers are preferable.

[0045] From the viewpoint of film-forming properties and processability, the polypropylene MFR may, in one embodiment, be 0.1 g / 10 min to 50 g / 10 min or 0.3 g / 10 min to 30 g / 10 min.

[0046] As for the polypropylene, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used.

[0047] The polypropylene content 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 even more preferably 95% by mass or more.

[0048] The polypropylene resin layer may contain resin materials other than polypropylene. Examples of resin materials include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polypropylene resin layer may contain the above-mentioned additives.

[0049] The polypropylene resin layer is a stretched layer. This improves, 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 as a packaging material for packaging containers that undergo boiling or retorting treatment. The stretching process can be either uniaxial stretching or biaxial stretching.

[0050] When stretching in the MD direction, the stretching ratio is preferably 2 to 15 times, more preferably 5 to 13 times. When stretching in the TD direction, the stretching ratio 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 layer can be further improved, and the printability of the polypropylene resin layer can also be improved. From the viewpoint of the fracture limit of the polypropylene resin layer, a stretching ratio of 15 times or less is preferable.

[0051] In one embodiment, the polypropylene resin layer may be subjected to the above-described surface treatment. This can, for example, improve the adhesion between the polypropylene resin layer and other layers. An easy-adhesion layer may be provided on the surface of the polypropylene resin layer.

[0052] 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 to 100 μm, more preferably 10 μm to 50 μm. If the thickness is above the lower limit, for example, the strength and heat resistance of the barrier laminate can be further improved. If the thickness is below the upper limit, for example, the processability of the barrier laminate can be further improved.

[0053] 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 represent characters, patterns, symbols, or combinations thereof. The printed layer can also be formed using biomass-derived ink. This further reduces the environmental impact. The method for forming the printed layer is as described above.

[0054] (Surface coating layer) In one embodiment, the barrier substrate comprises a surface coating layer containing a resin material having polar groups between a polypropylene resin layer and a vapor-deposited film. By providing a surface coating layer containing a resin material having polar groups, the adhesion of the vapor-deposited film formed on the surface coating layer can be improved, and the gas barrier properties can also be improved.

[0055] 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. This barrier substrate comprises the polypropylene resin layer, the surface coating layer, and the vapor-deposited film in this order in the thickness direction.

[0056] A polar group refers to a group containing one or more heteroatoms, and examples include ester groups, epoxy groups, hydroxyl groups, amino groups, amide groups, urethane groups, carboxyl groups, carbonyl groups, carboxylic acid anhydride groups, sulfo groups, thiol groups, and halogen groups. Among these, from the viewpoint of the lamination properties of packaging containers, carboxyl groups, carbonyl groups, ester groups, hydroxyl groups, amino groups, amide groups, and urethane groups are preferred, and carboxyl groups, hydroxyl groups, amide groups, and urethane groups are more preferred.

[0057] Examples of resin materials having polar groups include ethylene-vinyl alcohol copolymers (EVOH), polyvinyl alcohol (PVA), polyester, polyethyleneimine, hydroxyl group-containing (meth)acrylic resins, polyamides such as nylon 6, nylon 6,6, MXD nylon and amorphous nylon, and polyurethane. Among these, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, hydroxyl group-containing (meth)acrylic resins, polyamides and polyurethanes are more preferred.

[0058] 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.

[0059] The content of the resin material having polar groups 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 resin materials other than resin materials having polar groups. The surface coating layer may contain the above-mentioned additives.

[0060] The ratio of the thickness of the surface coating layer to the total thickness of the resin substrate is preferably 0.08% to 20%, more preferably 0.2% to 15%, even more preferably 1% to 10%, and even more preferably 1% to 5%. If the above ratio is above 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. If the above ratio is below the upper limit, for example, the processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0061] 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. If the thickness is above 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. If the thickness is below the upper limit, for example, the processability of the resin substrate and the recyclability of the packaging container can be further improved.

[0062] For example, a resin substrate can be produced by first forming a resin film from polypropylene or a resin composition containing polypropylene using a T-die method or an inflation method, then stretching the resin film, and finally applying a coating liquid for forming a surface coating layer to the stretched resin film and drying it.

[0063] (Surface resin layer) In one embodiment, the barrier substrate comprises a surface resin layer containing a resin material having a melting point of 180°C or higher (hereinafter also referred to as "high-melting-point resin material") between a polypropylene resin layer and a vapor-deposited film. By providing a surface resin layer containing the high-melting-point resin material, the adhesion of the vapor-deposited film formed on the surface resin layer can be improved, and the gas barrier properties can also be improved.

[0064] 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. This barrier substrate comprises the polypropylene resin layer, the surface resin layer, and the vapor-deposited film in this order in the thickness direction.

[0065] 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. If the melting point is above 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 lamination strength of the packaging container can be further improved.

[0066] 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. This can improve, for example, the film-forming properties of the resin substrate.

[0067] In this specification, the melting point can be measured in accordance with JIS K7121:2012 (Method for measuring the transition temperature of plastics). Specifically, the melting point can be determined by measuring the DSC curve using a differential scanning calorimetry (DSC) device at a heating rate of 10°C / min.

[0068] 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 to 80°C, more preferably 20°C to 60°C. If the above difference is below 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. If the above difference is below the upper limit, for example, the film-forming properties of the resin substrate can be further improved.

[0069] High melting point resin materials preferably have polar groups. A polar group refers to a group containing one or more heteroatoms, and examples include ester groups, epoxy groups, hydroxyl groups, amino groups, amide groups, urethane groups, carboxyl groups, carbonyl groups, carboxylic acid anhydride groups, sulfo groups, thiol groups, and halogen groups. Among these, from the viewpoint of gas barrier properties and laminate strength of packaging containers, hydroxyl groups, ester groups, amino groups, amide groups, carboxyl groups, and carbonyl groups are preferred, with amide groups being more preferred.

[0070] High-melting-point resin materials only need to have a melting point of 180°C or higher, and examples include polyolefins, vinyl resins, (meth)acrylic resins, polyamides, polyimides, polyesters, cellulose resins, and ionomer resins. For example, resin materials having a melting point of 180°C or higher and possessing polar groups are preferred, and ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyesters, and polyamides such as nylon 6, nylon 6,6, MXD nylon, and amorphous nylon are more preferred.

[0071] 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.

[0072] The surface resin layer may contain resin materials other than high-melting-point resin materials. The surface resin layer may contain the above-mentioned additives. The surface resin layer may be subjected to the above-mentioned surface treatment.

[0073] The ratio of the thickness of the surface resin layer to the total thickness of the resin substrate is preferably 1% to 10%, more preferably 1% to 5%. If the above ratio is above 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. If the above ratio is below the upper limit, for example, the film-forming properties and processability of the resin substrate, and the recyclability of the packaging container can be further improved.

[0074] The thickness of the surface resin layer is preferably 0.1 μm to 5 μm, more preferably 0.1 μm to 4 μm. If the thickness is above 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. If the thickness is below the upper limit, for example, the film-forming properties and processability of the resin substrate, and the recyclability of the packaging container can be further improved.

[0075] In one embodiment, the resin substrate may include an adhesive resin layer between the polypropylene resin layer and the surface resin layer. This improves the adhesion between these layers.

[0076] The adhesive resin layer can be formed, for example, from an adhesive resin. Examples of adhesive resins include polyethers, polyesters, polyurethanes, silicone resins, epoxy resins, vinyl resins, phenolic resins, polyolefins, and acid-modified polyolefins. Among these, polyolefins and their acid-modified products are preferred from the viewpoint of the recyclability of the packaging container, and polypropylene and its acid-modified products are more preferred.

[0077] The thickness of the adhesive resin layer is, for example, 1 μm to 15 μm. A thickness of 1 μm or more can further improve adhesion between, for example, the polypropylene resin layer and the surface resin layer. A thickness of 15 μm or less can further improve the processability of, for example, the resin substrate.

[0078] In one embodiment, a resin substrate having a polypropylene resin layer, an adhesive resin layer if necessary, and a surface resin layer is a co-extruded stretched resin film. The co-extruded stretched resin film can be produced, for example, by forming a film using a T-die method or an inflation method to obtain a laminated film, and then stretching the laminated film. The stretching of the laminated film may be performed simultaneously by forming the film using the inflation method.

[0079] The stretching process can be either uniaxial stretching or biaxial stretching. When stretching in the MD direction, the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less. When stretching in the TD direction, the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less.

[0080] (Vaporized film) The barrier substrate comprises a vapor-deposited film composed of an inorganic oxide. In one embodiment, the barrier substrate comprises a vapor-deposited film on a surface coating layer. In another embodiment, the barrier substrate comprises a vapor-deposited film on a surface resin layer. This improves 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 the mass reduction of the contents filled inside the packaging container.

[0081] 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.

[0082] In one embodiment, silica is more preferable as the inorganic oxide because aging treatment after vapor deposition film formation is not required. In another embodiment, carbon-containing silicon oxide is more preferable as the inorganic oxide because the decrease in gas barrier properties can be suppressed even when the barrier laminate is bent.

[0083] The thickness of the vapor-deposited film is preferably 1 nm to 150 nm, more preferably 5 nm to 60 nm, and even more preferably 10 nm to 40 nm. If the thickness is above the lower limit, for example, the oxygen barrier and water vapor barrier properties of the barrier laminate can be further improved. If the thickness is below 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.

[0084] It is preferable that the surface of the deposited film is subjected to the above-mentioned surface treatment. This improves the adhesion between the deposited film and the adjacent layer.

[0085] Examples of methods for forming deposited films include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition.

[0086] The deposited film may be a single layer formed by a single deposition process, or a multilayer formed by multiple deposition processes. If the deposited film is multilayer, each layer may be composed of the same inorganic oxide, or of different inorganic oxides. Each layer may be formed by the same method, or by different methods.

[0087] A vacuum deposition apparatus with plasma assistance can be used as the apparatus for forming a vapor-deposited film by the PVD method. One embodiment of a method for forming a vapor-deposited film using a vacuum deposition apparatus with plasma assistance is described below.

[0088] In one embodiment, the vacuum deposition apparatus, as shown in Figures 7 and 8, comprises a vacuum vessel A, an unwinding section B, a deposition drum C, a winding section D, a transport roll E, an evaporation source F, a reaction gas supply section G, an anti-deposition box H, a deposition material I, and a plasma gun J. Figure 7 is a schematic cross-sectional view of the vacuum deposition apparatus in the XZ plane. Figure 8 is a schematic cross-sectional view of the vacuum deposition apparatus in the XY plane.

[0089] As shown in Figure 7, the substrate S wound onto the film-forming drum C is positioned at the top of the vacuum vessel A with the surface intended for deposition facing downwards. Below the film-forming drum C in the vacuum vessel A, an electrically grounded protective box H is positioned. An evaporation source F is positioned on the bottom surface of the protective box H. The film-forming drum C is positioned in the vacuum vessel A such that the substrate S wound onto the film-forming drum C is positioned opposite the top surface of the evaporation source F at a certain distance. Conveyor rolls E are positioned 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 vessel A is connected to a vacuum pump (not shown). The evaporation source F holds the deposition material I and is equipped with a heating device (not shown). The reaction gas supply section G is the part that supplies reaction gases (oxygen, nitrogen, helium, argon, and mixtures thereof, etc.) that react with the evaporated deposition material I.

[0090] The vapor-deposited material I, heated and evaporated from the evaporation source F, is irradiated onto the substrate S. Simultaneously, plasma is also irradiated onto the substrate S from the plasma gun J, forming a vapor-deposited film on the substrate S. Details of the above film formation method are disclosed in Japanese Patent Publication No. 2011-214089.

[0091] Plasma generators used in plasma chemical vapor deposition (PVM) can include high-frequency plasma, pulsed-wave plasma, and microwave plasma generators. A device with two or more deposition chambers may also be used. Such a device preferably includes a vacuum pump and is capable of maintaining a vacuum in each deposition chamber. The vacuum level in each deposition chamber is 1 × 10 to 1 × 10 -6 Pa is preferable.

[0092] One embodiment of a method for depositing a vapor-deposited film using a plasma generator is described below. The substrate is sent to the deposition chamber and transported at a predetermined speed onto the surface of the cooling / electrode drum via auxiliary rolls. Next, a mixed gas composition containing a monomer gas for film formation containing inorganic oxides, oxygen gas, and an inert gas is supplied from the gas supply device into the deposition chamber. Plasma is generated on the substrate by glow discharge and irradiated to form a vapor-deposited film containing inorganic oxides on the substrate. Details of the above film formation method are disclosed in Japanese Patent Publication No. 2012-076292.

[0093] Figure 9 is a schematic diagram showing a plasma chemical vapor deposition apparatus used in the CVD method. In one embodiment, as shown in Figure 9, the plasma chemical vapor deposition apparatus unwinds a substrate S from an unwinding section B1 located inside a vacuum vessel A1 and transports the substrate S onto the surface of a cooling / electrode drum C1 at a predetermined speed via a transport roll E1. Oxygen, nitrogen, helium, argon, and mixed gases thereof are supplied from a reaction gas supply section G1, and film-forming monomer gases are supplied from a raw material gas supply section I1. While preparing a vapor deposition mixed gas composition consisting of these gases, the vapor deposition mixed gas composition is introduced into the vacuum vessel A1 through a raw material supply nozzle H1. Then, a plasma is generated on the substrate S transported onto the surface of the cooling / electrode drum C1 by a glow discharge plasma F1 and irradiated to form a vapor-deposited film on the substrate S. At this time, the cooling / electrode drum C1 is supplied with a predetermined power from a power supply K1 located outside the vacuum vessel A1, and a magnet J1 is placed near the cooling / electrode drum C1 to promote plasma generation. After the vapor-deposited film is formed, the substrate S is wound onto the winding section D1 via the transport roll E1 at a predetermined winding speed. In Figure 9, L1 represents the vacuum pump.

[0094] A continuous vapor deposition apparatus, equipped with a plasma pretreatment chamber and a deposition chamber, can be used as the apparatus for forming a vapor-deposited film. One embodiment of a method for forming a vapor-deposited film using such an apparatus is described below.

[0095] In the plasma pretreatment chamber, plasma is irradiated onto the substrate from a plasma supply nozzle. Next, in the film deposition chamber, a vapor-deposited film is formed on the plasma-treated substrate. Details of the above film deposition method are disclosed in International Publication No. 2019 / 087960.

[0096] The vapor-deposited film in the barrier substrate is preferably a vapor-deposited film formed by the CVD method, and more preferably a carbon-containing silicon oxide vapor-deposited film formed by the CVD method. This suppresses the decrease in gas barrier properties even when the barrier laminate is bent.

[0097] The carbon-containing silicon oxide vapor-deposited film contains silicon, oxygen, and carbon. In one embodiment of a 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 100% of the total of the three elements silicon, oxygen, and carbon. By setting the carbon content C within the above range, for example, the reduction in gas barrier properties can be suppressed even when the barrier laminate is bent. In this specification, the proportions of each element are expressed on a molar basis.

[0098] In one embodiment of a 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 oxygen content (O) within the above ranges, for example, the decrease in gas barrier properties can be further suppressed even when the barrier laminate is bent.

[0099] In one embodiment of a carbon-containing silicon oxide vapor-deposited film, the proportion of oxygen (O) is preferably higher than the proportion of carbon (C), and the proportion of silicon (Si) is preferably lower than the proportion of carbon (C). The proportion of oxygen (O) is preferably higher than the proportion of silicon (Si), meaning that the proportions are preferably decreasing in the order of O, C, and Si. This allows for, for example, further suppression of the decrease in gas barrier properties even when the barrier laminate is bent.

[0100] The proportions of C, Si, and O in a carbon-containing silicon oxide vapor-deposited film can be measured by X-ray photoelectron spectroscopy (XPS) using narrow-scan analysis under the following measurement conditions.

[0101] (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: MgKα (monochromatic X-ray, hν=1253.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): Approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ionic species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching area: 10mmφ Ion sputtering was performed for 30 seconds, and the spectrum was collected.

[0102] (Barrier coat layer) In one embodiment, the barrier substrate may further comprise a barrier coating layer on the vapor-deposited film. That is, the barrier substrate may further comprise a barrier coating layer on the surface of the vapor-deposited film opposite to the surface facing the polypropylene resin layer. This can improve, for example, the oxygen barrier properties and water vapor barrier properties of the barrier laminate.

[0103] In one embodiment, the barrier coat layer contains a gas barrier resin. Examples of gas barrier resins include ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyamides such as nylon 6, nylon 6,6 and polymethoxyylene adipamide, polyurethane, and (meth)acrylic resins.

[0104] The gas barrier resin content 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. With this configuration, for example, the gas barrier properties of the barrier coat layer can be improved. The barrier coat layer may contain the above-mentioned additives.

[0105] The thickness of the barrier coating layer containing the gas barrier resin is preferably 0.01 μm to 10 μm, more preferably 0.1 μm to 5 μm. By setting the thickness of the barrier coating layer to 0.01 μm or more, for example, the gas barrier properties can be further improved. By setting the thickness of the barrier coating layer to 10 μm or less, for example, the processability of the barrier laminate and the recyclability of the packaging container can be improved.

[0106] The barrier coating layer can be formed, for example, by applying and drying a coating solution obtained by dissolving or dispersing a material such as a gas barrier resin in water or a suitable organic solvent.

[0107] 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, and then applying and drying the gas barrier composition on the vapor-deposited film. The gas barrier coating film contains hydrolyzed polycondensates obtained by hydrolysis and polycondensation of the above-mentioned metal alkoxide, etc., by the 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.

[0108] 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 represent 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.

[0109] R 1 and R 2 Examples of the organic group in include alkyl groups having 1 to 8 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-hexyl group and n-octyl group. The metal atom M is, for example, silicon, zirconium, titanium or aluminum.

[0110] Examples of the metal alkoxide include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and tetrabutoxysilane.

[0111] Examples of the water-soluble polymer include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Depending on 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. Also, 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 usage amount of the water-soluble polymer is preferably 5 to 500 parts by mass with respect to 100 parts by mass of the metal alkoxide.

[0112] The surface of the gas barrier coating film has a silicon atom to carbon atom ratio (Si / C), measured by X-ray photoelectron spectroscopy (XPS), which is preferably 1.60 or less, more preferably 0.50 to 1.60, and even more preferably 0.90 to 1.35. If the above ratio is below the upper limit, for example, the decrease in gas barrier properties can be suppressed even when the barrier laminate is bent. If the above ratio is above the lower limit, for example, when manufacturing a packaging container using the barrier laminate, the decrease in gas barrier properties can be suppressed even when heating such as heat sealing is performed.

[0113] The above range of silicon-to-carbon atom ratios can be achieved by appropriately adjusting the amount of metal alkoxide used in the water-soluble polymer. In this specification, the silicon-to-carbon atom ratio is expressed on a molar basis.

[0114] The ratio of silicon atoms to carbon atoms can be measured by narrow-scan analysis under the following measurement conditions using X-ray photoelectron spectroscopy (XPS).

[0115] (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: MgKα (monochromatic X-ray, hν=1253.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): Approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ionic species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching area: 10mmφ Ion sputtering time: 30 seconds + 30 seconds + 60 seconds (total 120 seconds) A spectrum was collected.

[0116] As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, and organoalkoxysilanes having an epoxy group are preferred, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of silane coupling agent used is preferably 1 to 20 parts by mass per 100 parts by mass of metal alkoxide.

[0117] The gas barrier composition may contain water in a ratio of preferably 0.1 moles to 100 moles, more preferably 0.5 moles to 60 moles, per mole of metal alkoxide. By setting the water content above the lower limit, for example, the oxygen barrier and water vapor barrier properties of the barrier laminate can be improved. By setting the water content below the upper limit, for example, hydrolysis reactions can be carried out rapidly.

[0118] The gas barrier composition may contain an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0119] Acids or amine compounds are preferred as catalysts for the sol-gel method. Examples of acids 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 acid used is preferably 0.001 moles or more and 0.05 moles or less per mole of the total molar amount of the metal alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent.

[0120] Suitable amine compounds include tertiary amines that are substantially insoluble in water and soluble in organic solvents, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. The amount of amine compound used is preferably 0.01 parts by mass or more and 1.0 part by mass or less, and more preferably 0.03 parts by mass or more and 0.3 parts by mass or less, per 100 parts by mass of the total amount of the metal alkoxide and silane coupling agent.

[0121] Methods for applying the gas barrier composition include, for example, roll coating such as gravure roll coaters, spray coating, spin coating, dipping, brushing, bar coating, and application methods such as applicators.

[0122] The following describes one embodiment of a method for forming a gas barrier coating film. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent. A polycondensation reaction gradually proceeds within the composition. The composition is applied to a vapor-deposited film by a conventional method and dried. This drying further promotes the polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains one), forming a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above operation. For example, the applied composition is heated at a temperature preferably between 20°C and 150°C, more preferably between 50°C and 120°C, and even more preferably between 70°C and 100°C for 1 second to 10 minutes. This forms a gas barrier coating film.

[0123] 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. This allows for improved gas barrier properties, suppression of crack formation in the vapor-deposited film, and improved recyclability of the packaging container.

[0124] <Sealant layer> The barrier laminate of this disclosure comprises a sealant layer. In one embodiment, the sealant layer contains a resin material that can be fused together by heat. Examples of resin materials that can be fused together by heat include polyolefins, specifically polyethylene such as low-density polyethylene, linear low-density polyethylene and medium-density polyethylene, polypropylene, polybutene, methylpentene polymer, and cyclic olefin copolymer.

[0125] Examples of resin materials that can fuse with each other by heat include ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, ethylene-(meth)acrylate ethyl copolymer, ethylene-vinyl alcohol copolymer, ionomer resin, 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 resin.

[0126] 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 makes it possible to make the packaging container a monomaterial. After collecting used packaging containers, there is no need to separate the substrate and the sealant layer, which improves the recyclability of the packaging containers. By making the sealant layer of polypropylene, the oil resistance of the packaging container made using a barrier laminate can also be improved.

[0127] The polypropylene content 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 even more preferably 95% by mass or more. This can improve, for example, the recyclability of the packaging container.

[0128] When the sealant layer is made of polypropylene, the proportion of polypropylene to the total amount of resin material 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 makes it possible to produce, for example, a monomaterial packaging container using the barrier laminate, thereby improving the recyclability of the packaging container.

[0129] 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 / cm³. 3 More than 0.92g / cm 3 The following applies: Density is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C). From the perspective of reducing environmental impact, biomass-derived polypropylene and / or recycled polypropylene may be used. The sealant layer may contain the above-mentioned additives.

[0130] The sealant layer may have a single-layer structure or a multi-layer structure. The thickness of the sealant layer is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm. If the thickness is above the lower limit, for example, the lamination strength of the packaging container equipped with the barrier laminate can be further improved. If the thickness is below the upper limit, for example, the processability of the barrier laminate can be further improved. When making pouches (especially retort pouches) from the barrier laminate, the thickness of the sealant layer is even more preferably 30 μm to 100 μm.

[0131] The sealant layer is preferably an unstretched resin film, and more preferably an unstretched polypropylene resin film, from the viewpoint of heat sealability. The resin film can be manufactured, for example, by using a casting method, a T-die method, or an inflation method.

[0132] For example, an unstretched resin film corresponding to the sealant layer may be laminated onto the second substrate via an adhesive layer as needed, or the sealant layer may be formed by melt-extruding a resin material that can fuse with each other by heat onto the second substrate. Examples of adhesive layers include the following:

[0133] <Adhesive layer> In one embodiment, the barrier laminate includes a first adhesive layer between a first substrate and a second substrate. In another embodiment, the barrier laminate includes a second adhesive layer between the second substrate and a sealant layer. This improves the adhesion between the first substrate and the second substrate, and / or the adhesion between the second substrate and the sealant layer.

[0134] The adhesive layer is composed of an adhesive. The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive. In one embodiment, the barrier laminate of this disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer. This makes it possible to manufacture the laminate using an adhesive without directly applying the adhesive to the vapor-deposited film, thereby suppressing the degradation of the vapor-deposited film.

[0135] Examples of solvent-free adhesives, i.e., non-solvent laminate adhesives, include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing type urethane-based adhesives are more preferred.

[0136] In one embodiment, the solvent-free adhesive is a two-component curing adhesive comprising a main component and a curing agent. The weight-average molecular weight (Mw) of the polymer component contained in the main component is preferably 800 to 10,000, more preferably 1,200 to 4,000, from the viewpoint of coating suitability. The polydispersity (Mw / Mn) of the polymer component contained in the main component is preferably 2.8 or less, more preferably 1.2 to 2.7, even more preferably 1.5 to 2.6, and particularly preferably 2.0 to 2.5. Here, Mn is the number-average molecular weight of the polymer component contained in the main component. Each average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 (2008) and is a polystyrene equivalent value.

[0137] 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.

[0138] In one embodiment, by forming an adhesive layer using a solvent-free adhesive, the amount of residual solvent, specifically the amount of residual organic solvent, in the barrier laminate can be further reduced. The barrier laminate of this disclosure comprises a polypropylene resin layer and a polypropylene resin substrate. Therefore, when producing the barrier laminate of this disclosure using a solvent-type adhesive, it is necessary to lower the drying temperature compared to polyester-based laminates in order to prevent deterioration and thermal shrinkage of the laminate. In this case, the solvent in the adhesive may not be sufficiently volatilized and may remain in the barrier laminate, resulting in an odor due to the residual solvent. By using a solvent-free adhesive, the amount of residual solvent can be further reduced.

[0139] Examples of the above-mentioned organic solvents 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.

[0140] In one embodiment, by using a solvent-free adhesive, the adhesive layer can be made thinner compared to when a solvent-based adhesive is used. This allows for a further improvement in the polypropylene content of the entire barrier laminate. Such a barrier laminate is suitable for producing monomaterial packaging containers.

[0141] In one embodiment, using a solvent-free adhesive can further improve the tear resistance of the barrier laminate compared to using a solvent-based adhesive, as will be described later. This improvement in tear resistance is achieved by using a solvent-free adhesive, which allows for a thinner and harder adhesive layer.

[0142] 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.

[0143] In one embodiment, the barrier laminate of the present disclosure may be manufactured by laminating a first substrate, a second substrate, and a resin film corresponding to a sealant layer using a non-solvent laminating method with a solvent-free adhesive, or by laminating them using a dry laminating method with a solvent-type adhesive.

[0144] 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.

[0145] The following describes a two-component curing urethane adhesive. A preferred urethane adhesive is one that comprises a main component containing a polyol compound, such as polyester polyol, and a curing agent containing an isocyanate compound. Examples of polyol compounds include polyester polyols, polyether polyols, polycarbonate polyols, and (meth)acrylic polyols. Among these, polyester polyols are preferred.

[0146] Polyester polyols have two or more hydroxyl groups in one molecule. Polyester polyols have, for example, a polyester structure or a polyester polyurethane structure as their main skeleton. Polyester polyols can be obtained, for example, by a dehydration condensation reaction between a polyhydric alcohol component and a polyhydric carboxylic acid component, or by transesterification or ring-opening reactions.

[0147] 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 polyols with three or more functions, such as glycerin, triethylolpropane, trimethylolpropane, pentaerythritol, and sorbitol.

[0148] 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 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.

[0149] Polyester polyols can be pre-chained with polyisocyanates as needed. Examples of polyisocyanates include 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; as well as burettes, nurates, or trimethylolpropane adducts of diisocyanates.

[0150] The weight-average molecular weight (Mw) of polyol compounds such as polyester polyols is preferably 800 to 10,000, more preferably 1,200 to 4,000, from the viewpoint of coating suitability. The polydispersity (Mw / Mn) of polyol compounds such as polyester polyols is preferably 2.8 or less, more preferably 1.2 to 2.7, even more preferably 1.5 to 2.6, and particularly preferably 2.0 to 2.5. 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 polystyrene equivalent value.

[0151] Isocyanate compounds have two or more isocyanate groups in one molecule. Examples of isocyanate compounds include aromatic isocyanates and aliphatic isocyanates. The isocyanate compound may also be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known and conventional method.

[0152] Examples of isocyanate compounds 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, burettes, and allophanates obtained by reacting these diisocyanate compounds with low molecular weight active hydrogen compounds or their alkylene oxide adducts, or high molecular weight active hydrogen compounds.

[0153] Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, neneopentyl 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.

[0154] <Physical properties> In one embodiment, the barrier laminate of this disclosure exhibits the following thermal shrinkage rates. The MD direction refers to the flow direction of the laminate, and the TD direction refers to the direction perpendicular to the MD direction.

[0155] The thermal shrinkage rate (MD1) in the MD direction 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. A lower lower limit for the thermal shrinkage rate (MD1) is preferable, but it may be, for example, 0.10% or 0.20%. Barrier laminates with such a low thermal shrinkage rate (MD1) have excellent gas barrier properties and are also excellent in suitability for bag making when producing packaging bags by heat sealing.

[0156] 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. A lower lower limit for the thermal shrinkage rate (TD1) is preferable, but it may be, for example, 0.10%, 0.20%, or 0.50%. Barrier laminates with such low thermal shrinkage rates (TD1) as well as low thermal shrinkage rates (MD1) exhibit even better gas barrier properties and suitability for bag making. For example, it can suppress the occurrence of wrinkles and deformation in packaging bags made by heat sealing. In particular, a low thermal shrinkage rate (TD1) can suppress image distortion in the printed layer of the barrier laminate.

[0157] 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, 0.30 to 3.00, preferably 0.35 to 2.00, and more preferably 0.40 to 1.50. When the ratio (MD1 / TD1) is within this range, the laminate shrinks relatively uniformly in the MD and TD directions even after heat treatment, which can suppress image distortion in the printed layer of the barrier laminate, for example.

[0158] The thermal shrinkage rate (MD2) in the MD 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 3.10% or less. A lower lower limit for the thermal shrinkage rate (MD2) is preferable, but it may be, for example, 0.50% or 1.00%.

[0159] The thermal shrinkage rate (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. A lower lower limit for the thermal shrinkage rate (TD2) is preferable, but it may be, for example, 0.50% or 1.00%.

[0160] The ratio 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 (MD2 / TD2) 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.

[0161] Each thermal shrinkage rate is calculated using the following formula. Thermal shrinkage rate (MD) (%) = (Length of the laminate in the MD direction before heat treatment - Length of the laminate in the MD direction after heat treatment) / Length of the laminate in the MD direction before heat treatment × 100 Thermal shrinkage rate (TD) (%) = (Length of the laminate in the TD direction before heat treatment - Length of the laminate in the TD direction after heat treatment) / Length of the laminate in the TD direction before heat treatment × 100

[0162] In one embodiment, the barrier laminate of this disclosure exhibits the following tear strength. The tear strength is measured as follows: Sixteen barrier laminates are stacked alternately with their front and back sides facing each other, and the MD and TD directions of the films constituting the barrier laminates are aligned to prepare a sample. The tear strength of the sample in the MD and TD directions is measured in accordance with JIS K7128-2 (Elmendorf tear test), for example, using an Elmendorf tear tester No. 163 manufactured by Toyo Seiki Seisakusho Co., Ltd.

[0163] The tear strength (unit: N / 16 sheets) in the MD direction of the barrier laminate is, for example, 0.1 to 2.0, preferably 0.2 to 1.5.

[0164] The tear strength (in N / 16 sheets) in the TD direction of the barrier laminate is, for example, 0.1 to 6.0, preferably 0.2 to 5.5, and more preferably 0.5 to 5.0.

[0165] 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 ease of opening the packaging container made of the barrier laminate in the TD direction. For example, the tear strength in the TD direction can be further reduced by using a solvent-free adhesive when manufacturing the barrier laminate.

[0166] The ratio of the tear strength in the TD direction to the tear strength in the MD direction of a barrier laminate (strength) TD / strength MD The ratio 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.

[0167] In one embodiment, the above ratio (strength) TD / strength MD The value is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. This improves the ease of opening the packaging container made of barrier laminate in the TD direction.

[0168] In one embodiment, the amount of residual solvent in the barrier laminate of the present disclosure is 30 mg / m². 2 The following is preferable: 10 mg / m² 2 More preferably, 5 mg / m² 2 More preferably, 3 mg / m² 2 Below, 2mg / m 2 The following, or 1 mg / m² 2The following applies: A lower limit for the residual solvent amount is preferable, for example, 0.1 mg / m³. 2 or 0.2 mg / m² 2 But that's fine.

[0169] The amount of residual solvent can be measured by cutting a 10 cm square sample from the barrier laminate and using a calibration curve method with a gas chromatograph such as the GC-2014 manufactured by Shimadzu Corporation.

[0170] [Packaging container] The barrier laminates of this disclosure can be suitably used for packaging material applications. The packaging material is used to manufacture a packaging container. The packaging material comprises the barrier laminate of the present disclosure. A packaging container can be manufactured by using at least the packaging material comprising the barrier laminate of the present disclosure.

[0171] The packaging containers of this disclosure comprise the barrier laminate of this disclosure (hereinafter also simply referred to as the "laminated"). Examples of packaging containers include packaging bags, tube containers, and containers with lids. A container with a lid comprises a container body having a storage compartment and a lid material joined (heat-sealed) to the container body to seal the storage compartment.

[0172] In one embodiment, the packaging container of this disclosure maintains its gas barrier properties even after high-temperature processing and exhibits minimal deformation, making it suitable as a microwave oven container or a boiling or retorting container. The packaging container of this disclosure is also suitable as a microwave oven boiling or retorting container. The packaging container of this disclosure is particularly suitable as a boiling or retorting pouch.

[0173] Examples of heat sealing methods include bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals.

[0174] Examples of packaging bags include various types such as standing pouch type, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope seal type, gusset seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.

[0175] The packaging container may be equipped with an easy-open section. Examples of easy-open sections include a notch that serves as the starting point for tearing the packaging container, and a half-cut line formed by laser processing or a cutter as a path when tearing the packaging container.

[0176] The packaging container may be equipped with a steam venting mechanism. The steam venting mechanism is configured to allow steam to escape by connecting the inside and outside of the packaging container when the steam pressure inside the packaging container exceeds a predetermined value, while also preventing steam from escaping from other parts of the container.

[0177] The steam venting mechanism includes, for example, a steam venting seal protruding inward from the side seal portion of the packaging container, and an unsealed portion isolated from the contents storage portion by the steam venting seal portion. The unsealed portion communicates with the outside of the packaging container. The packaging container, filled with contents and with its opening heat-sealed, is heated using a microwave oven or the like. This increases the internal pressure, causing the steam venting seal portion to detach. Steam escapes to the outside of the packaging container through the detached steam venting seal portion and the unsealed portion.

[0178] In one embodiment, a packaging bag can be made by folding the laminate of the present disclosure in half so that the first substrate is on the outside and the sealant layer is on the inside, overlapping the two halves, and then heat-sealing the edges. In another embodiment, a packaging bag can be made by overlapping multiple laminates of the present disclosure so that the sealant layers face each other, and then heat-sealing the edges. The entire packaging bag may be made of the above laminate, or only a part of the packaging bag may be made of the above laminate.

[0179] In one embodiment, the laminate of the present disclosure is used as a lid material in a container with a lid. The container with a lid comprises a container body having a storage compartment and a lid material joined (heat-sealed) to the container body so as to seal the storage compartment. Here, the lid material, i.e., the sealant layer of the laminate, and the container body are heat-sealed. Examples of container body shapes include cup shape and bottomed cylindrical shape. The container body is made of, for example, polystyrene, polypropylene, polyethylene, or paper.

[0180] Examples of contents that can be contained in the packaging container include liquids, solids, powders, and gels. The contents may be food or beverages, or non-food items such as chemicals, cosmetics, and pharmaceuticals. After the contents are placed in the packaging container, the container can be sealed by heat-sealing the opening.

[0181] As specific examples of packaging bags, small bags and standing pouches will be described below. A small pouch is a small packaging bag used to contain contents weighing, for example, 1g to 200g. Examples of contents that can be contained in a small pouch include sauces, soy sauce, dressings, ketchup, syrups, cooking alcoholic beverages, other liquid or viscous seasonings; liquid soups, powdered soups, fruit juices; spices; liquid beverages, jelly beverages, instant foods, and other food and beverages.

[0182] Standing pouches are used to contain contents ranging from 50g to 2000g. Examples of contents that can be contained in standing pouches include shampoo, rinse, conditioner, hand soap, body soap, fragrances, deodorizers, insect repellents, detergents; dressings, cooking oils, mayonnaise, and other liquid or viscous condiments; liquid beverages, jelly beverages, instant foods, and other food and beverages; and creams.

[0183] Figure 10 shows a packaging bag 50 obtained by bonding two laminates together. The shaded area indicates a heat-sealed portion. The packaging bag 50 may be equipped with an easy-open section 51. Examples of the easy-open section 51 include a notch 52 that serves as a starting point for tearing, and a half-cut line 53 formed by laser processing or a cutter as a tearing path.

[0184] Figure 11 shows a simplified example of the configuration of a standing pouch. The shaded area indicates a heat-sealed portion. In one embodiment, the standing pouch 60 comprises a body (side sheet) 61 and a bottom (bottom sheet) 62. The side sheet 61 and the bottom sheet 62 may be made of the same material or of different materials. The bottom sheet 62 maintains the shape of the side sheet 61, thereby giving the pouch self-supporting ability and enabling it to be a standing pouch. A storage space for accommodating contents is formed within the area enclosed by the side sheet 61 and the bottom sheet 62.

[0185] The standing pouch 60 may be equipped with a steam venting mechanism 63. The steam venting mechanism 63 comprises a steam venting seal portion 63a that protrudes inward from the side seal portion toward the inside of the packaging container, and an unsealed portion 63b that is isolated from the contents containment portion by the steam venting seal portion 63a. The unsealed portion 63b is in communication with the outside of the packaging container.

[0186] In a standing pouch, the body may be made only of the laminate of the Disclosure, the bottom may be made only of the laminate of the Disclosure, or both the body and the bottom may be made of the laminate of the Disclosure.

[0187] In one embodiment, the side sheet can be formed by manufacturing a bag such that the sealant layer of the laminate of the present disclosure is the innermost layer. In another embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them so that the sealant layers face each other, and heat-sealing the side edges on both sides to form a bag.

[0188] In other embodiments, the side sheet can be formed by preparing two laminates of the present disclosure, stacking them with their sealant layers facing each other, inserting two folded laminates, each folded in a V-shape with the sealant layer on the outside, between the laminates at the side edges on both sides of the stacked laminates, and heat-sealing them. According to such a manufacturing method, a standing pouch having a body portion with side gussets can be obtained.

[0189] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower parts of the bagged side sheets and heat-sealing it. More specifically, the bottom sheet can be formed by inserting a laminate folded in a V-shape with the sealant layer on the outside between the lower parts of the bagged side sheets and heat-sealing it.

[0190] In one embodiment, two of the above laminates are prepared, stacked with their sealant layers facing each other, then another laminate is folded in a V-shape with the sealant layer on the outside, inserted between the lower parts of the stacked laminates facing each other, and heat-sealed to form the bottom. Then, the body portion is formed by heat-sealing two sides adjacent to the bottom. In this way, a standing pouch of one embodiment can be formed.

[0191] The present disclosure relates to, for example, the following [1] to

[18] . [1] A barrier laminate including a first base material, a second base material, and a sealant layer in this order in the thickness direction, wherein either one of the first base material and the second base material is a barrier base material including a polypropylene resin layer and a vapor deposition film, the other of the first base material and the second base material is a polypropylene resin base material, the polypropylene resin layer is a layer subjected to a stretching treatment, the vapor deposition film is composed of an inorganic oxide, and the polypropylene resin base material is a base material subjected to a stretching treatment. [2] The barrier laminate according to [1] above, wherein the first substrate is a barrier substrate, and the first substrate is arranged such that the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces away from the sealant layer, and the second substrate is a barrier substrate, and the second substrate is arranged such that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer. [3] The barrier laminate according to [1] or [2] above, wherein the first substrate is a polypropylene resin substrate and the second substrate is a barrier substrate. [4] The barrier laminate according to any one of [1] to [3] above, wherein the barrier substrate further comprises a surface coating layer between a polypropylene resin layer and a vapor-deposited film, and the surface coating layer contains a resin material having polar groups. [5] The barrier laminate according to any one of [1] to [3] above, wherein the barrier substrate further comprises a surface resin layer between a polypropylene resin layer and a vapor-deposited film, and the surface resin layer contains a resin material having a melting point of 180°C or higher. [6] The barrier laminate according to [5] above, wherein the polypropylene resin layer and the surface resin layer in the barrier substrate are co-extruded stretched resin films. [7] A barrier laminate according to any one of [1] to [6] above, further comprising a barrier coating layer on a vapor-deposited film. [8] The barrier laminate according to any one of [1] to [7] above, wherein the sealant layer is a resin layer made of polypropylene. [9] A barrier laminate according to any one of [1] to [8] above, comprising a first adhesive layer between a first substrate and a second substrate, and a second adhesive layer between the second substrate and a sealant layer.

[10] A barrier laminate according to any of [1] to [9] above, wherein the thermal shrinkage rate in the MD direction (MD1) after heat treatment at 120°C for 15 minutes is 2.00% or less, and the thermal shrinkage rate in the TD direction (TD1) is 2.00% or less.

[11] The barrier laminate according to

[10] above, wherein 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 0.30 or more and 3.00 or less.

[12] A barrier laminate according to any of [1] to

[11] above, wherein the thermal shrinkage rate in the MD direction (MD2) after heat treatment at 150°C for 5 minutes is 4.00% or less, and the thermal shrinkage rate in the TD direction (TD2) is 4.00% or less.

[13] The barrier laminate according to

[12] above, wherein the ratio of the thermal shrinkage rate (MD2) to the thermal shrinkage rate (TD2) (MD2 / TD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is 0.30 or more and 3.00 or less.

[14] A barrier laminate according to any of [1] to

[13] above, used for packaging container applications.

[15] A packaging container comprising a barrier laminate as described in any of [1] to

[14] above.

[16] The packaging container described in

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

[17] A lid material made of a barrier laminate as described in any of [1] to

[14] above.

[18] A packaging container comprising a container body having a storage compartment and a lid material as described in

[17] above, which is joined to the container body so as to seal the storage compartment. [Examples]

[0192] The barrier laminate of this disclosure will be described in detail below based on the examples provided.

[0193] [Fabrication of barrier substrates] 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) until the solid content concentration reached 10% by mass to prepare the main component.

[0194] An ethyl acetate solution containing tolylene diisocyanate (75% solids by mass) was added to the main component as a curing agent to obtain a solution for forming a surface coating layer. The amount of curing agent used was 10 parts by mass per 100 parts by mass of the main component.

[0195] A 20 μm thick biaxially oriented polypropylene film (ME-1, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) was prepared, with one side corona-treated. The above-mentioned surface coating layer forming solution was applied to the corona-treated side of the film and dried to form a 0.5 μm thick surface coating layer, thereby obtaining a resin substrate.

[0196] A 12 nm thick carbon-containing silicon oxide vapor deposition film was formed on the surface coating layer of a resin substrate using a low-temperature plasma chemical vapor deposition apparatus (CVD) by roll-to-roll, while applying tension to the resin substrate. The vapor deposition film formation conditions were as follows:

[0197] (Formation conditions) Hexamethyldisiloxane:Oxygen gas:Helium = 1:10:10 (unit: slm) • Cooling / electrode drum power supply: 22kW Line speed: 100m / min

[0198] The proportions of carbon (C), silicon (Si), and oxygen (O) in a carbon-containing silicon oxide vapor-deposited film were measured. The proportions of carbon (C), silicon (Si), and oxygen (O) were 32.7%, 29.8%, and 37.5%, respectively, relative to the total of 100% of the three elements (silicon, oxygen, and carbon). The proportions of each element were determined by narrow-scan analysis using X-ray photoelectron spectroscopy (XPS) under the measurement conditions described above.

[0199] 385 g of water, 67 g of isopropyl alcohol, and 9.1 g of 0.5 N hydrochloric acid were mixed to obtain a pH 2.2 solution. To this solution, 175 g of tetraethoxysilane as a metal alkoxide and 9.2 g of glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed while cooling to 10°C to obtain solution A.

[0200] Solution B was obtained by mixing 14.7 g of polyvinyl alcohol with a saponification value of 99% or higher and a degree of polymerization of 2400 as a water-soluble polymer, 324 g of water, and 17 g of isopropyl alcohol.

[0201] Solution A and solution B were mixed in a ratio of 6.5:3.5 by mass to obtain a barrier coating agent. The barrier coating agent was applied to 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. As described above, a transparent barrier substrate was obtained.

[0202] [Example 1] The biaxially oriented polypropylene film surface of the transparent barrier substrate described above was corona-treated to achieve a wet tensile strength of 38 dyn or higher. A 20 μm thick biaxially oriented polypropylene film (Toyobo Co., Ltd., P2171) was used as the first substrate, and the corona-treated transparent barrier substrate described above was used as the second substrate. A 60 μm thick unoriented polypropylene film (Toray Film Processing Co., Ltd., ZK207) was used as the sealant layer. These were dry-laminated via a polyester urethane adhesive (Rock Paint, RU-004 / H-1 (mixing ratio 7.5 / 1)), and 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.

[0203] A 10 cm square sample was cut from the obtained barrier laminate. The amount of residual solvent in this sample was measured using a calibration curve method with a Shimadzu GC-2014 gas chromatograph. The amount of residual solvent was 20 mg / m². 2 That was the case.

[0204] Sixteen of the obtained barrier laminates were stacked alternately with their front and back sides facing each other, and with the MD and TD directions of the films constituting the barrier laminates 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 Seisakusho Co., 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) was... TD / strength MD The score was 5.9.

[0205] [Example 1a] The biaxially oriented polypropylene film surface of the transparent barrier substrate described above was corona-treated to achieve a wet tensile strength of 38 dyn or higher. A 20 μm thick biaxially oriented polypropylene film (Toyobo Co., Ltd., P2171) was used as the first substrate, and the corona-treated transparent barrier substrate described above was used as the second substrate. A 60 μm thick unoriented polypropylene film (Toray Film Processing Co., Ltd., ZK207) was used as the sealant layer. These were laminated via a polyester urethane adhesive (Rock Paint, RN-920 / HN-920 (mixing ratio 1 / 1)) and 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 1 μm. The polypropylene content in the barrier laminate was 95% by mass.

[0206] The residual solvent content of the obtained barrier laminate was 0.7 mg / m². 2 That was the case. Sixteen of the obtained barrier laminates were stacked alternately with their front and back sides facing each other, and with the MD and TD directions of the films constituting the barrier laminates aligned, to prepare a sample. The tear strength in the MD direction of the sample was 0.6 N / 16 sheets, and the tear strength in the TD direction was 1.7 N / 16 sheets, and the tear strength ratio (strength) was... TD / strength MD The value was 2.8.

[0207] [Example 2] The transparent barrier substrate was used as the first substrate, a 20 μm thick biaxially oriented polypropylene film (Toyobo Co., Ltd., P2271) as the second substrate, and a 60 μm thick unoriented polypropylene film (Toray Film Processing Co., Ltd., ZK207) as the sealant layer. These were dry-laminated via a polyester urethane adhesive (Rock Paint, RU-004 / H-1 (mixing ratio 7.5 / 1)), and 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] [Comparative Example 1] The transparent barrier substrate described above was used as the first substrate, and a 60 μm thick unstretched polypropylene film (manufactured by Toray Film Processing Co., Ltd., ZK207) was used as a sealant layer. This was dry-laminated via a polyester urethane adhesive (manufactured by Rock Paint, RU-004 / H-1 (mixing ratio 7.5 / 1)), and 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 92% by mass.

[0209] [Gas barrier performance evaluation] The barrier laminate obtained above was cut out to obtain a test specimen. Using this test specimen, the oxygen permeability (cc / m³) was measured. 2 (day·atm) and water vapor transmission (g / m³) 2 The following method was used to measure the day(s).

[0210] Using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20), the test specimen was set so that the first substrate side was the oxygen supply side, and the oxygen permeability was measured in accordance with JIS K 7126 under conditions of 23°C and 90% RH relative humidity.

[0211] Using a water vapor transmission rate measuring device (MOCON, PERMATRAN-w 3 / 33), the first substrate side of the test specimen was set to face the water vapor supply side, and the water vapor transmission rate was measured in accordance with JIS K 7129 under conditions of 40°C and 90% RH relative humidity.

[0212] [Gas barrier property evaluation (after boiling or after retorting)] Using the barrier laminate obtained above, a flat packaging bag was fabricated. The size of the flat packaging bag is B5 size (182 mm x 257 mm). 150 mL of water was filled inside the flat packaging bag.

[0213] 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 specimen. Using this test specimen, the oxygen permeability and water vapor permeability were measured in the same manner as described above.

[0214] Flat packaging bags were retorted with hot water at 121°C for 30 minutes. A barrier laminate was cut out from the flat packaging bag to obtain a test specimen. Using this test specimen, the oxygen permeability and water vapor permeability were measured in the same manner as described above.

[0215] [Gas barrier property evaluation (after Gelboflex test)] A four-sided bag was fabricated using the two barrier laminates obtained above. The size of this bag was A4 size (210 mm x 297 mm). Using this bag, a gel flex test (stroke: 80 mm, bending motion: 400°) in accordance with ASTM F392 was repeated 10 times. After that, the barrier laminate was cut out from the bag to obtain a test specimen. Using this test specimen, the oxygen permeability and water vapor permeability were measured in the same manner as above.

[0216] [Gas barrier property evaluation (after boiling or retort treatment and Gelboflex test)] A four-sided bag was prepared using the two barrier laminates obtained above. The size of this bag was A4 size (210 mm x 297 mm). The inside of the bag was filled with 400 mL of water. The four-sided bag was boiled or retorted under the above conditions. After removing the water from the four-sided bag, the bag was used to repeat the Gelboflex test (stroke: 80 mm, bending motion: 400°) in accordance with ASTM F392 10 times. After that, the barrier laminate was cut out from the bag to obtain a test specimen. Using this test specimen, the oxygen permeability and water vapor permeability were measured in the same manner as above.

[0217] [Measurement of thermal shrinkage rate] The barrier laminate obtained above was cut to a size of 10 cm x 10 cm to obtain test specimens. The test specimens were placed in an oven and heated at 120°C for 15 minutes or at 150°C for 5 minutes. The lengths of the test specimens in the MD and TD directions were measured using a glass scale before and after heating in the oven. The thermal shrinkage rate in the MD direction (MD) and the thermal shrinkage rate in the TD direction (TD) were calculated based on the following formulas. Table 1 shows the average values ​​of the thermal shrinkage rates for the two test specimens.

[0218] Thermal shrinkage rate (MD) (%) = (Length of the laminate in the MD direction before heat treatment - Length of the laminate in the MD direction after heat treatment) / Length of the laminate in the MD direction before heat treatment × 100 Thermal shrinkage rate (TD) (%) = (Length of the laminate in the TD direction before heat treatment - Length of the laminate in the TD direction after heat treatment) / Length of the laminate in the TD direction before heat treatment × 100

[0219] [Table 1] [Explanation of Symbols]

[0220] 1: Barrier laminate, 10: Polypropylene resin substrate, 20: Barrier substrate, 22: Polypropylene resin layer, 23: Surface coating layer or surface resin layer, 24: Vapor-deposited film, 25: Barrier coating layer, 30: Sealant layer, 40A, 40B: Adhesive layer, 50: Packaging bag, 51: Easy-open section, 52: Notch section, 53: Half-cut line, 60: Standing pouch, 61: Body (side sheet), 62: Bottom (bottom sheet), 63: Steam venting mechanism, 63a: Steam venting seal, 63b: Unsealed part A: Vacuum vessel, B: Unwinding section, C: Film deposition drum, D: Winding section, E: Conveyor roll, F: Evaporation source, G: Reaction gas supply section, H: Anti-adhesion box, I: Evaporation material, J: Plasma gun, S: Substrate, A1: Vacuum vessel, B1: Unwinding section, C1: Cooling / electrode drum, D1: Winding section, E1: Conveyor roll, F1: Glow discharge plasma, G1: Reaction gas supply section, H1: Raw material supply nozzle, I1: Raw material gas supply section, J1: Magnet, K1: Power supply, L1: Vacuum pump

Claims

1. The first substrate and A second substrate and sealant layer and A barrier laminate having these elements 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, and the other of the first substrate or the second substrate is a polypropylene resin substrate. The aforementioned polypropylene resin layer is a layer that has undergone stretching treatment. The aforementioned deposited film is composed of an inorganic oxide, The aforementioned polypropylene resin substrate is a substrate that has undergone stretching treatment. Barrier laminate.

2. When the first substrate is the barrier substrate, the first substrate is arranged such that the vapor-deposited film faces the sealant layer and the polypropylene resin layer faces the opposite side from the sealant layer. If the second substrate is the barrier substrate, the second substrate is arranged such that the vapor-deposited film faces the first substrate and the polypropylene resin layer faces the sealant layer. The barrier laminate according to claim 1.

3. The first substrate is the polypropylene resin substrate, The second substrate is the barrier substrate. The barrier laminate according to claim 1 or 2.

4. The barrier laminate according to any one of claims 1 to 3, 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 polar groups.

5. The barrier laminate according to any one of claims 1 to 3, 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.

6. The barrier laminate according to claim 5, wherein the polypropylene resin layer and the surface resin layer in the barrier substrate are co-extruded stretched resin films.

7. The barrier laminate according to any one of claims 1 to 6, further comprising a barrier coating layer on the vapor-deposited film.

8. The barrier laminate according to any one of claims 1 to 7, wherein the sealant layer is a resin layer made of polypropylene.

9. A first adhesive layer is provided between the first substrate and the second substrate. A second adhesive layer is provided between the second substrate and the sealant layer. A barrier laminate according to any one of claims 1 to 8.

10. A barrier laminate according to any one of claims 1 to 9, wherein the thermal shrinkage rate in the MD direction (MD1) of the barrier laminate after heat treatment at 120°C for 15 minutes is 2.00% or less, and the thermal shrinkage rate in the TD direction (TD1) is 2.00% or less.

11. The barrier laminate according to claim 10, wherein 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 0.30 or more and 3.00 or less.

12. The barrier laminate according to any one of claims 1 to 11, wherein the thermal shrinkage rate in the MD direction (MD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is 4.00% or less, and the thermal shrinkage rate in the TD direction (TD2) is 4.00% or less.

13. The barrier laminate according to claim 12, wherein the ratio of the thermal shrinkage rate (MD2) to the thermal shrinkage rate (TD2) (MD2 / TD2) of the barrier laminate after heat treatment at 150°C for 5 minutes is 0.30 or more and 3.00 or less.

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

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

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

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

18. A packaging container comprising a container body having a storage compartment, and a lid material according to claim 17, which is joined to the container body so as to seal the storage compartment.

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