Barrier sealant films, laminates, and packaging bags

Abstract

To provide a barrier sealant film which is useful as a sealant layer in a packaging material for manufacturing a packaging bag excellent in recyclability and aroma retention property.SOLUTION: A barrier sealant film includes at least a polyolefin layer and a barrier resin layer, wherein the polyolefin layer contains polyolefin as a main component, and the barrier resin layer contains a hetero atom-containing resin as a main component.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to barrier sealant films, laminates, and packaging bags. [Background technology]

[0002] Packaging bags are used to contain fluid contents such as liquids and powders. Packaging bags are composed of a laminate comprising a base material and a sealant layer. For example, polyolefin film is widely used as a sealant layer because it is flexible, transparent, and has excellent heat-sealing properties. Also, stretched polyester film or stretched polyamide film is widely used as a base material because it has excellent strength and heat resistance.

[0003] In recent years, there has been a growing demand for recycling packaging bags from the perspective of reducing environmental impact. From a recycling standpoint, it is preferable that the base material and the sealant layer be made of the same type of resin material (monomaterialization). For example, Patent Document 1 proposes that the base material and sealant layer be made of polyethylene. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-55156 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The Disclosers investigated using a laminate comprising a stretched polyolefin film as a base material to produce a packaging bag, instead of a stretched polyester film and a stretched polyamide film. However, such packaging bags did not retain fragrance sufficiently, and the odor of the contents of the packaging bag tended to leak out of the bag.

[0006] One problem of the present disclosure is to provide a barrier sealant film useful as a sealant layer in a packaging material for producing a packaging bag excellent in recyclability and fragrance retention properties.

Means for Solving the Problems

[0007] The barrier sealant film of the present disclosure includes at least a polyolefin layer and a barrier resin layer. The polyolefin layer contains polyolefin as a main component, and the barrier resin layer contains a heteroatom-containing resin as a main component.

Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a barrier sealant film useful as a sealant layer in a packaging material for producing a packaging bag excellent in recyclability and fragrance retention properties.

Brief Description of the Drawings

[0009]

Figure 1

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Modes for Carrying Out the Invention

[0010] The embodiments of this disclosure will be described in detail below. This disclosure can be implemented in many different forms and is not construed as being limited to the embodiments described below. The drawings may schematically represent the width, thickness, and shape of each layer, etc., compared to the embodiments, in order to clarify the explanation, but these are merely examples and do not limit the interpretation of this disclosure. In this specification and in each figure, elements similar to those already described in the previously shown figures are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0011] In the following description, each component (for example, polyolefins such as polyethylene and polypropylene, α-olefins, resin materials such as heteroatom-containing resins and adhesive resins, and additives) may be used individually or in combination of two or more types. "Main component" refers to a component that is present in the layer or substrate at a concentration of 50% by mass or more.

[0012] [Barrier sealant film] The barrier sealant film of this disclosure is Polyolefin layer, Barrier resin layer and It must have at least the following:

[0013] The polyolefin layer contains polyolefin as its main component. In this disclosure, "polyolefin layer" means a layer containing polyolefin such as polyethylene and polypropylene as its main component. The barrier resin layer contains a heteroatom-containing resin as its main component. The barrier sealant film is preferably an unstretched film.

[0014] The barrier sealant film comprises a barrier resin layer containing a heteroatom-containing resin as its main component. The barrier sealant film may also comprise, for example, a polyolefin layer, an adhesive resin layer, a barrier resin layer, an adhesive resin layer, and a polyolefin layer in this order.

[0015] The polyolefin content in the barrier sealant film is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. This can improve the recyclability of packaging bags, for example.

[0016] The thickness of the barrier sealant film is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, particularly preferably 80 μm or more, preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. For sealant films having a multilayer structure, it is preferable that the total thickness is within the above range. If the thickness is above the lower limit, for example, the heat sealability of the sealant film and the recyclability of the packaging bag can be improved. If the thickness is below the upper limit, for example, the processability of the sealant film can be improved.

[0017] From the viewpoint of heat-sealability, the barrier sealant film is preferably an unstretched resin film, more preferably an unstretched co-extruded resin film, and each layer constituting the sealant layer is a co-extruded resin layer. The above resin film can be manufactured, for example, by using the casting method, the T-die method, or the inflation method. The term "unstretched" includes not only films that are not stretched at all, but also films that are slightly stretched due to the tension applied during film formation.

[0018] In one embodiment, the barrier sealant film is a co-extruded resin film. In one embodiment, the barrier sealant film is a resin film obtained by co-extruding a material constituting a polyolefin layer, a material constituting an adhesive resin layer if the barrier sealant film includes an adhesive resin layer, and a material constituting a barrier resin layer using a co-extrusion inflation method.

[0019] The barrier sealant film may be surface-treated. This can improve, for example, the adhesion between the barrier sealant film and other layers. Examples of surface treatment methods include physical treatments such as corona treatment, ozone treatment, low-temperature plasma treatment using oxygen and / or nitrogen gas, and glow discharge treatment; and chemical treatments such as oxidation treatment using chemicals.

[0020] <Layer structure of sealant film> The following are some examples of the layer structure of the barrier sealant film described herein. The barrier sealant film 1 shown in Figure 1 comprises a polyolefin layer 2 and a barrier resin layer 4. The barrier sealant film 1 shown in Figure 2 comprises a polyolefin layer 2, a polyolefin layer 2, a polyolefin layer 2, an adhesive resin layer 3, and a barrier resin layer 4 in that order. The barrier sealant film 1 shown in Figure 3 comprises a polyolefin layer 2, an adhesive resin layer 3, a barrier resin layer 4, an adhesive resin layer 3, and a polyolefin layer 2 in that order.

[0021] <Polyolefin layer> The polyolefin layer contains polyolefin as its main component. Examples of polyolefins include polyethylene, polypropylene, and polymethylpentene. A polyethylene layer and a polypropylene layer are preferred as the polyolefin layer, and a polyethylene layer is more preferred.

[0022] The melt flow rate (MFR) of polyolefins is preferably 0.1 g / 10 min or higher, more preferably 0.3 g / 10 min or higher, even more preferably 0.5 g / 10 min or higher, preferably 50 g / 10 min or lower, more preferably 30 g / 10 min or lower, and even more preferably 10 g / 10 min or lower, from the viewpoint of film-forming properties and processability. If the MFR is above the lower limit, for example, the processability of sealant films can be improved. If the MFR is below the upper limit, for example, film-forming properties can be improved. The MFR of polyolefins is measured by Method A in accordance with JIS K7210, under a load of 2.16 kg. The measurement temperature for the MFR is set according to the melting point of the polyolefin, for example, 190°C for polyethylene and 230°C for polypropylene.

[0023] The polyolefin content in the polyolefin layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more or 95% by mass or more.

[0024] The polyolefin layer may contain resin materials other than polyolefin. Examples of such resin materials include (meth)acrylic resin, vinyl resin, cellulose resin, polyamide, polyester, and ionomer resin.

[0025] The polyolefin layer may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, slip agents, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins.

[0026] The thickness of the polyolefin layer is preferably 10 μm or more, more preferably 20 μm or more, preferably 200 μm or less, and more preferably 150 μm or less. If the thickness is above the lower limit, for example, the strength and recyclability of the sealant film can be improved. If the thickness is below the upper limit, for example, the processability of the sealant film can be improved. If the barrier sealant film comprises two or more polyolefin layers, the above "thickness" refers to the sum of the thicknesses of each polyolefin layer.

[0027] The barrier sealant film may have one polyolefin layer or two or more layers.

[0028] (Polyethylene layer) The polyethylene layer contains polyethylene as its main component. In this disclosure, polyethylene refers to a polymer in which the content of ethylene-derived structural units is 50 mol% or more of the total repeating structural units. In this polymer, the content of ethylene-derived structural units is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more. The above content can be measured by NMR spectroscopy.

[0029] In this disclosure, polyethylene may be a homopolymer of ethylene, or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of ethylenically unsaturated monomers other than ethylene include α-olefins having 2 to 20 carbon atoms, such as propylene, 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; vinyl monomers such as vinyl acetate and vinyl propionate; and (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate.

[0030] In the present disclosure, examples of the polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. From the viewpoint of heat sealability, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene are preferable. From the viewpoint of reducing environmental impact, polyethylene derived from biomass or polyethylene obtained by mechanical recycling or chemical recycling may be used as the polyethylene.

[0031] In the present disclosure, the density of the polyethylene is as follows. The density of the high-density polyethylene is preferably more than 0.945 g / cm 3 , , 3 , 3 , , ,

[0032] , 3 The upper limit of the density of the high-density polyethylene is, for example, 0.965 g / cm 3 The density of the medium-density polyethylene is preferably more than 0.930 g / cm 3 and not more than 0.945 g / cm 3 The density of the low-density polyethylene is preferably more than 0.900 g / cm 3 and not more than 0.930 g / cm 3 The density of the linear low-density polyethylene is preferably more than 0.900 g / cm 3 and not more than 0.930 g / cm 3 The density of the ultra-low-density polyethylene is preferably not more than 0.900 g / cm 3 The lower limit of the density of the ultra-low-density polyethylene is, for example, 0.860 g / cm 3 The density of the polyethylene is measured in accordance with JIS K7112 (particularly Method D (density gradient column method, 23°C)). The density of the layer described later is also measured by the same method.

[0032] The low-density polyethylene is usually polyethylene (high-pressure process low-density polyethylene) obtained by polymerizing ethylene by a high-pressure polymerization method. The linear low-density polyethylene is usually polyethylene obtained by polymerizing ethylene and a small amount of α-olefin by a polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst.

[0033] Polyethylenes with different densities or branching can be obtained by appropriately selecting a polymerization method. For example, it is preferable to use a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as the polymerization catalyst, and to carry out polymerization in one or more stages using one of the following methods: gas-phase polymerization, slurry polymerization, solution polymerization, or high-pressure ionic polymerization. The above explanation of polyethylene can be applied to other areas as well.

[0034] The melting point (Tm) of the polyethylene constituting the sealant layer is preferably 90°C or higher, more preferably 92°C or higher, preferably 140°C or lower, and more preferably 130°C or lower, from the viewpoint of balancing heat resistance and heat sealability. Tm is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0035] The polyethylene content in the polyethylene layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more or 95% by mass or more. This can improve the recyclability of the packaging bag, for example.

[0036] (Polypropylene layer) The polypropylene layer contains polypropylene as its main component. This can improve, for example, the oil resistance of packaging bags.

[0037] Polypropylene may be any of propylene homopolymer (homopolypropylene), propylene random copolymer (random polypropylene), or propylene block copolymer (block polypropylene), or a mixture of two or more selected from these. From the viewpoint of reducing environmental impact, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used as the polypropylene.

[0038] A propylene homopolymer is a polymer consisting 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 consisting of at least propylene and polymer blocks consisting of at least α-olefins other than propylene.

[0039] Examples of α-olefins other than propylene 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.

[0040] Among polypropylenes, propylene random copolymer is preferred from the viewpoint of transparency. If rigidity and heat resistance of the packaging bag are important, propylene homopolymer is preferred. If impact resistance of the packaging bag is important, propylene block copolymer is preferred.

[0041] The density of polypropylene, from the perspective of heat sealability, is, for example, 0.88 g / cm³. 3 More than 0.92g / cm 3 The following applies: The density of polypropylene is measured in accordance with JIS K7112 (especially Method D (density gradient tube method, 23°C)).

[0042] The melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 125°C or higher, even more preferably 130°C or higher, preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower, from the viewpoint of balancing heat resistance and heat sealability.

[0043] The polypropylene content in the polypropylene layer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. This can improve the recyclability of the packaging bag, for example.

[0044] <Barrier resin layer> The barrier sealant film of this disclosure comprises a barrier resin layer mainly composed of a heteroatom-containing resin. For example, in a laminate comprising at least a stretched substrate and a sealant layer, by using a substrate mainly composed of polyolefin as the stretched substrate and the barrier sealant film as the sealant layer, the recyclability and aroma retention of the packaging bag comprising the laminate can be improved, as well as the gas barrier properties (particularly oxygen barrier properties) and impact resistance can be improved.

[0045] Because the barrier sealant film of this disclosure comprises the barrier resin layer described above, in one embodiment it exhibits superior rigidity compared to conventional polyolefin sealant films. Therefore, a standing pouch equipped with such a barrier sealant film exhibits superior self-supporting properties.

[0046] Because the barrier sealant film of this disclosure comprises the barrier resin layer described above, in one embodiment it exhibits superior tear resistance compared to conventional polyolefin sealant films. Therefore, a packaging bag equipped with such a barrier sealant film exhibits superior openability.

[0047] Because the barrier sealant film of this disclosure comprises the barrier resin layer described above, in one embodiment it exhibits superior puncture resistance compared to conventional polyolefin sealant films. Therefore, packaging bags equipped with such a barrier sealant film exhibit superior filling performance for hard contents.

[0048] Examples of heteroatoms in heteroatom-containing resins include oxygen atoms, sulfur atoms, nitrogen atoms, and chlorine atoms. Heteroatom-containing resins have heteroatom-containing groups such as hydroxyl groups and amide groups. Examples of heteroatom-containing resins include ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyamides, polyvinylidene chloride, polyether polyols, and polyester polyols. Among these, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred from the viewpoint of aroma retention, gas barrier properties (especially oxygen barrier properties), rigidity, tear resistance, puncture resistance, and impact resistance, ethylene-vinyl alcohol copolymers and polyamides are more preferred, and ethylene-vinyl alcohol copolymers are even more preferred from the viewpoint of aroma retention and gas barrier properties.

[0049] Ethylene-vinyl alcohol copolymers (EVOHs) can be obtained, for example, by copolymerizing ethylene with a vinyl ester monomer and then saponifying the mixture. Copolymerization of ethylene with a vinyl ester monomer can be carried out by any known polymerization method, such as solution polymerization, suspension polymerization, or emulsion polymerization.

[0050] Vinyl acetate is generally used as the vinyl ester monomer, but other vinyl ester monomers may also be used. Examples of other vinyl ester monomers include aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl versatate; and aromatic vinyl esters such as vinyl benzoate.

[0051] In EVOH, the content of ethylene-derived constituent units (ethylene content) is preferably 20 mol% or more, more preferably 25 mol% or more, preferably 60 mol% or less, and more preferably 50 mol% or less. If the ethylene content is above the lower limit, for example, the processability of barrier sealant films can be improved. If the ethylene content is below the upper limit, for example, the aroma retention of packaging bags can be improved, as well as the oxygen barrier and water vapor barrier properties of barrier sealant films can be improved. The ethylene content is measured by NMR spectroscopy.

[0052] The average degree of saponification in EVOH may be 90 mol% or higher, 95 mol% or higher, or 99 mol% or higher. The average degree of saponification is measured in accordance with JIS K6726 (however, EVOH should be a solution homogeneously dissolved in water / methanol solvent).

[0053] The melting point (Tm) of EVOH is preferably 140°C or higher, more preferably 145°C or higher, even more preferably 150°C or higher, preferably 200°C or lower, more preferably 195°C or lower, and even more preferably 190°C or lower, from the viewpoint of heat resistance. The Tm of EVOH is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0054] The melt flow rate (MFR) of EVOH is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.5 g / 10 min or more, preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5.0 g / 10 min or less, from the viewpoint of film-forming properties and processability. The MFR of EVOH is measured in accordance with ASTM D1238 under conditions of a temperature of 190°C and a load of 2.16 kg. The measurement temperature may be 210°C depending on the melting point of EVOH.

[0055] EVOH may be modified by known methods such as urethaneization, acetalization, cyanoethylation, or oxyalkyleneization.

[0056] The average degree of saponification of polyvinyl alcohol (PVA) may be 70 mol% or higher, 75 mol% or higher, 80 mol% or higher, or 85 mol% or higher. The average degree of saponification shall be measured in accordance with JIS K6726.

[0057] Examples of polyamides include aliphatic polyamides and semi-aromatic polyamides. Aliphatic polyamides are preferred, and crystalline aliphatic polyamides are more preferred.

[0058] Examples of aliphatic polyamides include aliphatic homopolyamides and aliphatic copolymer polyamides. In the following examples, polyamide will also be referred to as "PA".

[0059] Aliphatic homopolyamides include, specifically, polycaprolactam (PA6), polyenanthractam (PA7), polyundecanelactam (PA11), polylauryllactam (PA12), polyhexamethyleneadipamide (PA66), polytetramethylenedodecamid (PA412), polypentamethyleneazeramid (PA59), polypentamethylenesebamide (PA510), polypentamethylenedodecamid (PA512), polyhexamethyleneazeramid (PA69), polyhexamethylenesebamide (PA610), polyhexamethylenedodecamid (PA612), and poly Examples include nonamethylene adipamide (PA96), polynonamethylene azeramide (PA99), polynonamethylene sevacamide (PA910), polynonamethylene dodecamide (PA912), polydecamethylene adipamide (PA106), polydecamethylene azeramide (PA109), polydecamethylene decamido (PA1010), polydecamethylene dodecamide (PA1012), polidodecamethylene adipamide (PA126), polidodecamethylene azeramide (PA129), polidodecamethylene sevacamide (PA1210), and polidodecamethylene dodecamide (PA1212).

[0060] Specifically, aliphatic copolymer polyamides include caprolactam / hexamethylenediaminoadipic acid copolymer (PA6 / 66), caprolactam / hexamethylenediaminoazelaic acid copolymer (PA6 / 69), caprolactam / hexamethylenediaminosebacic acid copolymer (PA6 / 610), caprolactam / hexamethylenediaminoundecanoic acid copolymer (PA6 / 611), caprolactam / hexamethylenediaminododecanoic acid copolymer (PA6 / 612), and caprolactam / amino Examples include undecanoic acid copolymer (PA6 / 11), caprolactam / lauryl lactam copolymer (PA6 / 12), caprolactam / hexamethylenediaminoadipic acid / lauryl lactam copolymer (PA6 / 66 / 12), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminosebacic acid copolymer (PA6 / 66 / 610), and caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminododecanedicarboxylic acid copolymer (PA6 / 66 / 612).

[0061] The relative viscosity of the aliphatic polyamide is preferably 1.5 to 5.0, more preferably 2.0 to 5.0, and even more preferably 2.5 to 4.5. The relative viscosity of the aliphatic polyamide is measured in accordance with JIS K6920 by dissolving 1 g of polyamide in 100 mL of 96% concentrated sulfuric acid and measuring at 25°C.

[0062] Semi-aromatic polyamides are polyamides having structural units derived from aromatic diamines and structural units derived from aliphatic dicarboxylic acids, or polyamides having structural units derived from aliphatic diamines and structural units derived from aromatic dicarboxylic acids. Examples include polyamides composed of aromatic diamines and aliphatic dicarboxylic acids, and polyamides composed of aliphatic diamines and aromatic dicarboxylic acids.

[0063] Examples of semi-aromatic polyamides include polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6I), polynonameethylene terephthalamide (PA9T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (PA66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (PA66 / 6I), polyhexamethylene terephthalamide / polycaproamide copolymer (PA6T / 6), polyhexamethylene isophthalamide / polycaproamide copolymer (PA6I / 6), and polyhexamethylene terephthalamide / poly Examples include dodecamide copolymer (PA6T / 12), polyhexamethylene isophthalamide / polyhexamethylene terephthalamide copolymer (PA6I / 6T), polyhexamethylene terephthalamide / poly(2-methylpentamethylene terephthalamide) copolymer (PA6T / M5T), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (PA66 / 6T / 6I), polyhexamethylene adipamide / polycaproamide / polyhexamethylene isophthalamide copolymer (PA66 / 6 / 6I), and polymetaxylylene adipamide (PAMXD6).

[0064] The melt volume rate (MVR) of the semi-aromatic polyamide is preferably 5 cm². 3 / 200cm for more than 10 minutes 3 / 10 minutes or less, or more preferably 10 cm 3 / 100cm for more than 10 minutes 3 The time is less than 10 minutes. MVR is measured in accordance with ISO 1133 at a temperature of 275°C and a load of 5 kg.

[0065] As the polyamide, crystalline aliphatic polyamides are preferred. Examples of crystalline aliphatic polyamides include PA6, PA11, PA12, PA66, PA610, PA612, PA6 / 66, and PA6 / 66 / 12.

[0066] The melting point (Tm) of crystalline aliphatic polyamide is preferably 180°C or higher, preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower. The Tm of the polyamide is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0067] The content of heteroatom-containing resin in the barrier resin layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more or 95% by mass or more. This makes it possible to improve the aforementioned physical properties of the packaging bag, such as aroma retention and gas barrier properties (especially oxygen barrier properties).

[0068] The barrier resin layer may contain the above-mentioned additives.

[0069] The thickness of the barrier resin layer in the barrier sealant film is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 20 μm or less. If the thickness is above the lower limit, the above-mentioned physical properties such as the aroma retention of the packaging bag can be improved. If the thickness is below the upper limit, the recyclability of the laminate can be improved. If the barrier sealant film comprises two or more barrier resin layers, the above "thickness" means the sum of the thicknesses of each barrier resin layer.

[0070] The thickness of the barrier resin layer is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less, relative to the thickness of the barrier sealant film. If the barrier sealant film comprises two or more barrier resin layers, the above "thickness" refers to the sum of the thicknesses of each barrier resin layer.

[0071] <Adhesive resin layer> The barrier sealant film of this disclosure may include an adhesive resin layer between the polyolefin layer and the barrier resin layer. This can improve, for example, the adhesion between the polyolefin layer and the barrier resin layer.

[0072] The adhesive resin layer contains a resin material. Examples of resin materials include polyolefins, modified polyolefins, vinyl resins, polyethers, polyesters, polyurethanes, silicone resins, epoxy resins, and phenolic resins. Among these, polyolefins and modified polyolefins are preferred from the viewpoint of recyclability and adhesion, and modified polyolefins such as acid-modified polyolefins are more preferred.

[0073] Examples of modified polyolefins include polyolefins modified with unsaturated carboxylic acids such as maleic acid and fumaric acid, or their acid anhydrides, esters, or metal salts, particularly graft-modified polyolefins. Among resin materials, modified polyolefins are preferred from the viewpoint of obtaining a structure suitable for monomaterial packaging materials.

[0074] The melt flow rate (MFR) of modified polyolefins may be 0.1 g / 10 min or higher, 0.3 g / 10 min or higher, 0.5 g / 10 min or higher, 50 g / 10 min or lower, 30 g / 10 min or lower, or 10 g / 10 min or lower, from the viewpoint of film-forming properties and processability. The MFR of modified polyolefins is measured in accordance with ASTM D1238 under conditions of a temperature of 190°C and a load of 2.16 kg, but the measurement temperature may be changed according to the melting point of the modified polyolefin.

[0075] The adhesive resin layer may contain the above-mentioned additives.

[0076] The thickness of the adhesive resin layer is preferably 5 μm or more, more preferably 10 μm or more, preferably 60 μm or less, and more preferably 50 μm or less. If the thickness is above the lower limit, for example, the adhesion can be improved. If the thickness is below the upper limit, for example, the recyclability of the laminate can be improved. If the barrier sealant film comprises two or more adhesive resin layers, the above "thickness" means the sum of the thicknesses of each adhesive resin layer.

[0077] Specifically, barrier sealant films include: (1) a film comprising a linear low-density polyethylene layer, an adhesive resin layer, and a barrier resin layer in that order; (2) a film comprising a linear low-density polyethylene layer, a linear low-density polyethylene layer, a linear low-density polyethylene layer, an adhesive resin layer, and a barrier resin layer in that order; and (3) a film comprising a linear low-density polyethylene layer, an adhesive resin layer, a barrier resin layer, an adhesive resin layer, and a medium-density polyethylene layer in that order. Here, the linear low-density polyethylene layer mainly contains linear low-density polyethylene, and the medium-density polyethylene layer mainly contains medium-density polyethylene. When a laminate described later is made using film (1) or (2), for example, the barrier resin layer is arranged to face the stretched substrate side. When a laminate described later is made using film (3), for example, the medium-density polyethylene layer is arranged to face the stretched substrate side.

[0078] The linear low-density polyethylene content in the linear low-density polyethylene layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more or 95% by mass or more.

[0079] The content of medium-density polyethylene in the medium-density polyethylene layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more or 95% by mass or more.

[0080] In the films described in (1) to (3) above, the melting point of the outermost linear low-density polyethylene layer is preferably 112°C or lower, more preferably 110°C or lower, even more preferably 105°C or lower, and particularly preferably 100°C or lower, and may also be 80°C or higher, or 90°C or higher.

[0081] In this specification, the melting points of the layers are values ​​obtained using a differential scanning calorimeter in accordance with JIS K7121:2012. Specifically, samples are taken from each layer and their melting points are measured using the method described in the Examples section.

[0082] In the films described in (1) to (3) above, the density of the outermost linear low-density polyethylene layer is preferably 0.915 g / cm³ from the viewpoint of low-temperature sealing properties. 3 More preferably, 0.912 g / cm³ 3 More preferably, 0.908 g / cm³ 3 The following is particularly preferred: 0.905 g / cm³ 3 The following is true: 0.900 g / cm³ 3 Even "super" is fine.

[0083] In the film described in (3) above, the melting point of the medium-density polyethylene layer is preferably 114°C or higher, more preferably 117°C or higher, and even more preferably 120°C or higher, but may also be 140°C or lower, or 135°C or lower, from the viewpoint of rigidity and tearability.

[0084] In the film described in (3) above, the density of the medium-density polyethylene layer is preferably 0.930 g / cm³ from the viewpoint of rigidity and tear resistance. 3 More preferably 0.935 g / cm³ 3 That is all, 0.945 g / cm³ 3 The following is also acceptable.

[0085] In the film described in (3) above, the difference between the melting point of the medium-density polyethylene layer and the melting point of the linear low-density polyethylene layer is preferably 4°C or higher, more preferably 15°C or higher, even more preferably 20°C or higher, preferably 50°C or lower, more preferably 48°C or lower, even more preferably 46°C or lower, and may be, for example, 40°C or lower.

[0086] [Laminated structure] The laminate of this disclosure comprises at least a stretched substrate and a sealant layer. The laminate of this disclosure can be suitably used as a packaging material.

[0087] The stretched substrate contains polyolefin as its main component. The sealant layer is the barrier sealant film of this disclosure.

[0088] In one embodiment, by having polyolefins as the main components of both the resin constituting the stretched substrate and the resin constituting the sealant layer, the recyclability of the laminate can be improved, for example.

[0089] The content of polyolefin (specifically polyethylene or polypropylene) in the entire laminate of this disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. This allows, for example, the production of monomaterial packaging bags using the above laminate, thereby improving the recyclability of the packaging bags. There is no particular upper limit to the polyolefin content, but it may be 99% by mass or 95% by mass.

[0090] The oxygen permeability of the laminate of this disclosure is preferably 200 cc / m². 2 • Day ATM or less, more preferably 50cc / m 2 • day·atm or less, more preferably 10 cc / m³ 2 • day·atm or less, particularly preferably 5cc / m³ 2 The oxygen permeability is less than or equal to 0.1 cc / m³. The lower limit of oxygen permeability is, for example, 0.1 cc / m³. 2•day•atm is also acceptable, or 1cc / m 2 •day•atm is also acceptable. Oxygen permeability is measured in accordance with JIS K7126-2 (isobaric method) under conditions of 23°C and 90% RH humidity.

[0091] The water vapor permeability of the laminate of this disclosure is preferably 10 g / m². 2 • Less than 5g / m² per day, more preferably 5g / m² 2 • Less than or equal to 3 g / m², more preferably 3 g / m² 2 • Less than 2 g / m², particularly preferably 2 g / m² 2 It is less than or equal to 1 day. The lower limit of water vapor transmission is, for example, 0.1 g / m³. 2 • Day is also acceptable. Water vapor transmission rate is measured in accordance with JIS K7129 (Method B) under conditions of 40°C and 90% RH humidity.

[0092] <Stretched base material> The stretched substrate contains polyolefin as its main component. Examples of polyolefins include polyethylene, polypropylene, and polymethylpentene, as detailed above. Polyethylene substrates and polypropylene substrates are preferred as the polyolefin substrate, with polyethylene substrates being more preferred.

[0093] The polyolefin MFR is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, even more preferably 0.5 g / 10 min or more, preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 5.0 g / 10 min or less, from the viewpoint of film-forming properties and processability.

[0094] The polyolefin content in the stretched substrate is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0095] The stretched substrate may contain resin materials other than polyolefins. The stretched substrate may contain the above-mentioned additives.

[0096] A stretched substrate is a substrate that has undergone a stretching treatment. This can improve, for example, the strength, heat resistance, and transparency of the substrate. The stretching treatment may be uniaxial stretching or biaxial stretching. When stretching in the longitudinal direction (the flow direction of the substrate, MD), the stretching ratio may be 2 times or more, 3 times or more, 10 times or less, or 7 times or less. When stretching in the transverse direction (the direction perpendicular to MD, TD), the stretching ratio may be 2 times or more, 3 times or more, 10 times or less, or 7 times or less. The stretched substrate is, for example, a substrate that has been uniaxially stretched to MD.

[0097] The haze value of the stretched substrate may be 25% or less, 15% or less, or 10% or less. The lower limit of the haze value may be 0.1% or 1%. The haze value of the stretched substrate shall be measured in accordance with JIS K7136.

[0098] The thickness of the stretched substrate is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. If the thickness is above the lower limit, for example, the strength and heat resistance of the stretched substrate can be improved. If the thickness is below the upper limit, for example, the processability of the stretched substrate can be improved.

[0099] A stretched substrate can be produced, for example, by forming a film from the resin compositions constituting each layer using an inflation molding method or a T-die molding method, and then stretching the film. With the inflation molding method, film formation and stretching can be performed simultaneously.

[0100] In one embodiment, the stretched substrate is a co-extruded resin film. In one embodiment, the stretched substrate is a resin film obtained by co-extruding multiple materials constituting a polyolefin layer using a co-extrusion inflation method, and then further stretching it.

[0101] The stretched substrate may be subjected to the above-mentioned surface treatment. This can, for example, improve the adhesion between the stretched substrate and other layers.

[0102] The stretched substrate may have a single-layer structure or a multilayer structure. A stretched substrate having a multilayer structure is preferred, for example, from the viewpoint of having an excellent balance of strength, heat resistance, printability and stretchability. The stretched substrate may have two or more polyolefin layers. In this case, the number of polyolefin layers may be two or more, three or more, seven or fewer, or five or fewer, for example, three, five, or seven layers.

[0103] (Polyethylene base material) Polyethylene substrates contain polyethylene as their main component. Details of polyethylene are as described above. From the viewpoint of the strength and heat resistance of the substrate, high-density polyethylene and medium-density polyethylene are preferred. From the viewpoint of the film-forming properties and processability of the substrate, linear low-density polyethylene and medium-density polyethylene are preferred. Medium-density polyethylene is particularly preferred. As polyethylene, from the viewpoint of reducing environmental impact, biomass-derived polyethylene or polyethylene that has been mechanically or chemically recycled may be used.

[0104] From the viewpoint of heat resistance, the melting point (Tm) of polyethylene is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, particularly preferably 120°C or higher, and preferably 140°C or lower.

[0105] The polyethylene content in the polyethylene substrate is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate can be improved.

[0106] The polyethylene substrate may be a uniaxially oriented film or a biaxially oriented film, for example, a uniaxially oriented film stretched in the longitudinal direction (MD). Details of the stretching process are as described above.

[0107] Examples of polyethylene substrates having a multilayer structure include the following: (1) A substrate comprising, in this order, a medium-density polyethylene layer, a high-density polyethylene layer, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene layer, and a medium-density polyethylene layer; (2) A substrate comprising, in this order, a medium-density polyethylene layer, a medium-density polyethylene layer, a blend layer of medium-density polyethylene and linear low-density polyethylene, a medium-density polyethylene layer, and a medium-density polyethylene layer; (3) A substrate comprising, in this order, a blend layer of medium-density polyethylene and high-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a linear low-density polyethylene layer, a blend layer of medium-density polyethylene and linear low-density polyethylene, and a blend layer of medium-density polyethylene and high-density polyethylene; (4) A substrate comprising, in this order, a blend layer of medium-density polyethylene and high-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, and a blend layer of medium-density polyethylene and high-density polyethylene; (5) A substrate comprising, in this order, a blend layer of high-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, a blend layer of linear low-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, and a blend layer of high-density polyethylene and medium-density polyethylene; (6) A substrate comprising, in this order, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene-containing layer, a linear low-density polyethylene layer, a high-density polyethylene layer, and a blend layer of medium-density polyethylene and high-density polyethylene; (7) A substrate comprising, in this order, a blend layer of medium-density polyethylene and high-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a linear low-density polyethylene layer, a high-density polyethylene layer, and a blend layer of medium-density polyethylene and high-density polyethylene; (8) A substrate comprising, in this order, a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer or an ultra-low-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer; (9) A substrate comprising, in this order, a high-density polyethylene layer, a blend layer of high-density polyethylene and medium-density polyethylene, a low-density polyethylene layer, a linear low-density polyethylene layer or an ultra-low-density polyethylene layer, a blend layer of high-density polyethylene and medium-density polyethylene, and a high-density polyethylene layer; (10) A substrate comprising, in this order, a high-density polyethylene layer, a high-density polyethylene layer, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene layer, and high-density polyethylene; (11) A substrate comprising, in this order, a medium-density polyethylene layer, a high-density polyethylene layer, a linear low-density polyethylene layer, a high-density polyethylene layer, and a medium-density polyethylene layer.

[0108] Each of the substrates described in (1) to (11) above comprises five layers. The layers are described as the 1st to 5th layers in order from the outside. The thickness of the 1st and 5th layers may be 0.5 μm or more, 1 μm or more, 10 μm or less, 8 μm or less, or 5 μm or less. The thickness of the 2nd and 4th layers may be 0.5 μm or more, 1 μm or more, 15 μm or less, 10 μm or less, or 8 μm or less. The thickness of the 3rd layer may be 1 μm or more, 2 μm or more, 5 μm or more, 50 μm or less, 40 μm or less, or 30 μm or less.

[0109] The following are examples of polyethylene substrates having a multilayer structure. (12) A substrate comprising a high-density polyethylene layer and a medium-density polyethylene layer in this order; (13) A substrate comprising a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer in this order.

[0110] (Polypropylene base material) The polypropylene substrate contains polypropylene as its main component. By including the polypropylene substrate in the laminate of this disclosure, for example, the oil resistance of packaging bags made using the laminate can be improved. Details of polypropylene are as described above.

[0111] The melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 150°C or higher, and preferably 170°C or lower, from the viewpoint of heat resistance. Tm is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0112] The polypropylene content in the polypropylene substrate is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate can be improved.

[0113] The polypropylene substrate may be a uniaxially oriented film or a biaxially oriented film; for example, a biaxially oriented film is used. The details of the stretching process are as described above. <Print layer> The laminate of this disclosure may include a printed layer. The printed layer includes an image. Examples of images include letters, figures, patterns, symbols, and combinations thereof. The image may include textual information such as the product name, the name of the contents in the packaging bag, the manufacturer, and the names of the raw materials. The image may be a solid color (a so-called solid image).

[0114] The printed layer contains, for example, colorants such as pigments and dyes. The printed layer may also be formed using, for example, biomass-derived inks. This can further reduce the environmental impact. The printed layer may also be, for example, a white layer.

[0115] Methods for forming the printed layer include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. From the viewpoint of reducing environmental impact, flexographic printing may also be used.

[0116] The thickness of the printed layer may be 0.5 μm or more, 1.0 μm or more, 10 μm or less, 6.0 μm or less, or 4.0 μm or less.

[0117] The printed layer may be formed on any surface of the stretched substrate. It is preferable that the printed layer be formed on the surface of the stretched substrate that is on the side of the sealant layer, as this suppresses contact between the printed layer and the outside air and suppresses deterioration of the printed layer over time.

[0118] <Sealant layer> The laminate of this disclosure comprises the barrier sealant film described above as a sealant layer. This makes it possible to create a monomaterial packaging bag. After collecting used packaging bags, there is no need to separate the stretched substrate and the sealant layer, improving the recyclability of the packaging bags.

[0119] For example, a barrier sealant film of the present disclosure corresponding to a sealant layer may be laminated onto a stretched substrate via an adhesive layer as needed. Examples of adhesive layers include those described later.

[0120] <Adhesive layer> The laminate of this disclosure may include an adhesive layer between any layers, such as between the stretched substrate and the sealant layer. This improves the adhesion between the stretched substrate and the sealant layer.

[0121] The thickness of the adhesive layer may be 0.1 μm or more, 0.2 μm or more, 0.5 μm or more, 10 μm or less, 8.0 μm or less, or 6.0 μm or less. The thickness of the adhesive layer may also be 2.0 μm or less.

[0122] In one embodiment, the adhesive layer may be an adhesive layer 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] In one embodiment, by forming an adhesive layer using a solvent-free adhesive, the amount of residual solvent in the laminate, specifically the amount of residual organic solvent, can be further reduced. Examples of 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.

[0127] 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 polyolefin content of the entire laminate. Such a laminate is suitable for producing monomaterial packaging bags. In one embodiment, by using a solvent-free adhesive, the tear resistance of the laminate can be further improved compared to when a solvent-based adhesive is used.

[0128] 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.

[0129] Examples of polyol compounds include polyester polyols, polyether polyols, polycarbonate polyols, and (meth)acrylic polyols. Among these, polyester polyols are preferred.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] The adhesive layer may be an adhesive resin layer containing a thermoplastic resin. Examples of thermoplastic resins include high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, and resins obtained by graft polymerization or copolymerization of polyolefins with unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, or ester monomers. The thermoplastic resin may be made from fossil fuel-derived materials, biomass-derived materials, or both.

[0139] In one embodiment, the laminate of the present disclosure may be manufactured by laminating a stretched substrate and a resin film corresponding to a sealant layer using a non-solvent lamination method with a solvent-free adhesive, or by laminating them using a dry lamination method with a solvent-type adhesive.

[0140] <Layer structure of the laminate> The following are some examples of the layer configuration of the laminates described herein. The laminate 5 shown in Figure 4 comprises a stretched substrate 8, an adhesive layer 6, and a barrier sealant film 1 in that order. In Figure 4, the layer structure of the barrier sealant film 1 is omitted. The laminate 5 may further include a printed layer, not shown, on the surface of the stretched substrate 8 facing the barrier sealant film 1.

[0141] [Packaging bag] The laminates of this disclosure are suitably used for packaging material applications. The packaging material is used to manufacture packaging bags. By using at least the laminates of this disclosure, packaging bags with excellent aroma retention can be manufactured. The packaging bags may be refill pouches, particularly standing pouches, that contain fluid contents such as liquids or powders that are transferred into containers such as bottles.

[0142] Examples of packaging bags include various types such as standing pouches, side-sealed bags, two-sided sealed bags, three-sided sealed bags, four-sided sealed bags, envelope-type sealed bags, gusseted sealed bags (pillow seal type), pleated sealed bags, flat-bottom sealed bags, square-bottom sealed bags, and gusseted bags. The packaging bags may also be small bags or resealable bags. The packaging bag may be, for example, a flexible packaging bag.

[0143] The packaging bag of this disclosure comprises the laminate of this disclosure. The packaging bags of this disclosure are, for example, A compartment for storing contents, The seal portion where the sealant layers of the laminate are joined together, It holds. The sealing portion includes an inner edge that defines the housing portion. The packaging bag may further have an easy-open line to enhance the tearability of the packaging bag. The packaging bag may further have a notch that serves as a starting point for tearing.

[0144] <Seal part> The packaging bag has a sealed section where the sealant layers of the laminate are joined together. Methods for forming a seal include, for example, heat sealing, which involves melting the sealant layers of a laminate by heating and fusing the sealant layers together. Specifically, these include bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals.

[0145] <Contents> Examples of contents that can be contained in the packaging bag 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 bag, the opening of the packaging bag can be sealed by heat sealing.

[0146] Examples of contents include shampoo, rinse, conditioner, hand soap, body soap, fragrances, deodorizers, insect repellents, fabric softeners, detergents; sauces, soy sauce, dressings, cooking oils, mayonnaise, ketchup, syrups, cooking alcoholic beverages, and other liquid or viscous condiments; fruit juices; spices; liquid beverages, jelly beverages, liquid soups, powdered soups, instant foods, and other food and beverages; and creams. In one embodiment, the packaging bag of this disclosure is a monomaterialized packaging material, yet it has excellent fragrance retention as described above. Therefore, even when strongly scented contents such as shampoo, rinse, conditioner, fabric softener, and detergent are filled into the packaging bag, odor leakage can be suppressed.

[0147] <Production of packaging bags> In one embodiment, a packaging bag can be made by folding the laminate of the present disclosure in half so that the stretched base material 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.

[0148] <Example of a packaging bag> Hereinafter, several examples of embodiments of the packaging bags of this disclosure will be described with reference to the drawings. Figure 5 is a front view showing a packaging bag 10 according to one embodiment. Figure 5 shows the packaging bag 10 before it is filled with contents (when it does not contain contents). The packaging bag 10 is a gusset-type pouch that is configured to stand upright. The packaging bag 10 includes an upper part 11, a lower part 12, and side parts 13, and has a substantially rectangular outline in the front view. Names such as "upper part," "lower part," and "side part," as well as terms such as "upper" and "lower," merely describe the relative position and orientation of the packaging bag 10 and its components based on the state in which the packaging bag 10 stands upright with the gusset part facing downwards. The orientation of the packaging bag 10 during transport or use is not limited by the names and terms used herein.

[0149] The packaging bag 10 has a storage section 17 and a sealing section 19. The storage section 17 contains the contents. The sealing section 19 includes an inner edge 19x that defines the storage section 17. The sealing section 19 is formed by joining the sealant layers of the laminate that constitute the packaging bag 10. In plan views such as Figure 5, the sealing section 19 is hatched.

[0150] The storage section 17 may include a spout section 20. The spout section 20 is the part through which the contents pass when the contents are removed from the packaging bag 10. The width of the spout section 20 is narrower than the width of the other parts of the storage section 17. Therefore, the user can accurately determine the direction in which the contents are dispensed from the packaging bag 10 through the spout section 20.

[0151] The packaging bag 10 may have an easy-open line 26. The easy-open line 26 can be formed on the packaging bag 10, for example, to improve its tearability. The easy-open line 26 crosses the storage section 17 in a plan view of the packaging bag 10. In the example shown in Figure 5, the easy-open line 26 crosses the spout section 20 in a plan view. As shown in Figure 5, a notch 28 adjacent to the easy-open line 26 may be formed on the outer edge of the packaging bag 10. Instead of a notch 28, a cut may be formed on the outer edge of the packaging bag 10.

[0152] The packaging bag 10 comprises a surface film 14 that constitutes the front surface, a back film 15 that constitutes the back surface, and a bottom film 16 that constitutes the bottom 12. The bottom film 16 is folded over at the folded portion 16f and positioned between the surface film 14 and the back film 15.

[0153] Either or both of the surface film 14 and the back film 15 are made of the laminate of the Disclosure. The bottom film 16 may also be made of the laminate of the Disclosure. The laminate includes an inner surface and an outer surface. The inner surface is the surface in contact with the contents. The outer surface is the surface located opposite the inner surface. The sealant layer is located on the inner side with respect to the stretched substrate.

[0154] The terms "front film," "back film," and "bottom film" are merely ways of defining each film according to its positional relationship, and the method of providing the film when manufacturing the packaging bag 10 is not limited by these terms. For example, the packaging bag 10 may be manufactured using a single film in which the front film 14, back film 15, and bottom film 16 are connected; it may be manufactured using a total of two films: a single film in which the front film 14 and bottom film 16 are connected and a single back film 15; or it may be manufactured using a total of three films: a single front film 14, a single back film 15, and a single bottom film 16.

[0155] As shown in Figure 5, the seal portion 19 includes a lower seal portion 12a, a side seal portion 13a, and a spout seal portion 20a. The lower seal portion 12a extends to the lower part 12. The side seal portion 13a extends along a pair of side portions 13. The spout seal portion 20a defines the spout portion 20. The distance between the inner edges of the spout seal portion 20a is smaller than the distance between the inner edges of the pair of side seal portions 13a. When the spout portion 20 is formed in a corner between the upper part 11 and the side portion 13 of the packaging bag 10, the spout seal portion 20a is connected to the side seal portion 13a.

[0156] In the packaging bag 10 when it does not contain any contents, the top 11 of the packaging bag 10 is an opening 11b, as shown in Figure 5. After the contents are placed in the packaging bag 10 through the opening 11b, the sealant layer of the surface film 14 and the sealant layer of the back film 15 are joined at the top 11, thereby forming an upper seal portion at the opening 11b. This seals the contents portion 17 from the outside of the packaging bag 10.

[0157] The side seal portion 13a, the spout seal portion 20a, and the upper seal portion are formed by joining the sealant layer of the surface film 14 and the sealant layer of the back film 15. The lower seal portion 12a includes the portion where the sealant layer of the surface film 14 and the sealant layer of the lower film 16 are joined, and the portion where the sealant layer of the back film 15 and the sealant layer of the lower film 16 are joined. As shown by the dotted line labeled 13c in Figure 5, a notch may be formed in a part of the lower film 16. At the location of the notch, the sealant layer of the surface film 14 and the sealant layer of the back film 15 may be joined.

[0158] Next, the layer structure of the lower film 16 will be described. The layer configuration of the lower film 16 is arbitrary, as long as it has an inner surface that can be bonded to the sealant layer of the surface film 14 and the sealant layer of the back film 15. For example, the above-described laminate may be used as the lower film 16, similar to the surface film 14 and the back film 15. Alternatively, a film with a different configuration from the laminate of this disclosure may be used as the lower film 16.

[0159] The packaging bag 10 can be manufactured, for example, as follows: Prepare the laminate according to the present disclosure. Cut the laminate in half. This yields a surface film 14 and a back film 15. Next, insert the folded lower film 16 between the surface film 14 and the back film 15. Subsequently, heat seal the sealant layers of each film to form seal portions such as the lower seal portion 12a, the side seal portion 13a, and the spout seal portion 20a. Cut the films joined together by heat sealing into an appropriate shape. This yields the packaging bag 10 shown in Figure 5.

[0160] Next, the contents are filled into the storage section 17 of the packaging bag 10. Then, the top section 11 is heat-sealed to form the top seal. In this way, a packaging bag 10 containing and sealed with contents is obtained.

[0161] In the above description of the embodiments, an example was shown in which the packaging bag 10 is a gusset-type pouch, but the specific configuration of the packaging bag 10 is not particularly limited.

[0162] For example, the packaging bag 10 does not have to have a lower film 16, as shown in Figures 6 and 7. In Figures 6 and 7, the lower seal portion 12a and the side seal portion 13a of the packaging bag 10 are formed by joining the sealant layers of the laminated surface film 14 and back film 15, respectively. After the contents are placed in the packaging bag 10, the packaging bag 10 is sealed by joining the sealant layer of the surface film 14 and the sealant layer of the back film 15 at the opening 11b of the upper part 11. The packaging bag 10 shown in Figures 6 and 7 may have an easy-open line 26.

[0163] As shown in Figure 8, the packaging bag 10 may be a pillow pouch. The packaging bag 10 includes a gusset portion 18 formed by overlapping the edges of the laminates that make up the surface film 14 and the back film 15. The gusset portion 18 includes a gusset seal portion 18a where the sealant layers of the laminates are joined together. The packaging bag 10 shown in Figure 8 may have an easy-open line 26. As shown in Figure 8, a notch 28 or an incision (not shown) may be formed on the outer edge of the gusset portion.

[0164] This disclosure relates, for example, to the following [1] to

[12] . [1] A barrier sealant film comprising at least a polyolefin layer and a barrier resin layer, wherein the polyolefin layer contains polyolefin as a main component and the barrier resin layer contains heteroatom-containing resin as a main component. [2] The barrier sealant film according to [1], wherein the heteroatom-containing resin comprises at least one selected from ethylene-vinyl alcohol copolymer, polyvinyl alcohol, and polyamide. [3] The barrier sealant film according to [1] or [2], wherein the barrier sealant film comprises the polyolefin layer, an adhesive resin layer, the barrier resin layer, an adhesive resin layer, and the polyolefin layer in this order. [4] The barrier sealant film according to [3], wherein the barrier sealant film comprises, in this order, the polyolefin layer containing linear low-density polyethylene as the main component, the adhesive resin layer, the barrier resin layer containing ethylene-vinyl alcohol copolymer or polyamide as the main component, the adhesive resin layer, and the polyolefin layer containing medium-density polyethylene as the main component. [5] A barrier sealant film according to any one of the above [1] to [4], wherein the thickness of the barrier resin layer is 1 μm or more and 30 μm or less. [6] A barrier sealant film according to any one of the above [1] to [5], which is a co-extruded resin film. [7] A laminate comprising at least a stretched substrate and a sealant layer, wherein the stretched substrate contains polyolefin as a main component and the sealant layer is a barrier sealant film according to any one of [1] to [6] above. [8] The laminate according to [7], wherein the laminate comprises an adhesive layer between the stretched substrate and the sealant layer. [9] The laminate according to [8], wherein the adhesive layer is an adhesive layer having a thickness of 0.1 μm or more and 2.0 μm or less.

[10] The laminate according to any one of the above [7] to [9], wherein the stretched substrate contains polyethylene as the main component and the polyolefin layer of the barrier sealant film is a polyethylene layer, or the stretched substrate contains polypropylene as the main component and the polyolefin layer of the barrier sealant film is a polypropylene layer.

[11] The laminate according to any one of the above [7] to

[10] , wherein the content of polyolefin in the entire laminate is 80% by mass or more.

[12] A packaging bag comprising the laminate described in any one of the above items [7] to

[11] . [Examples]

[0165] The barrier sealant film, laminate, and packaging bag of this disclosure will be described in more detail below with reference to examples, but the barrier sealant film, laminate, and packaging bag of this disclosure are not limited to the following examples.

[0166] [Production of stretched substrate] The following materials were used in the preparation of the stretched substrate. Medium-density polyethylene (MDPE) Product name: Elite5538G, manufactured by Dowchemical. Density: 0.941g / cm 3 Melting point: 129℃, MFR: 1.3g / 10min • High-density polyethylene (HDPE) Product name: Elite5960G, manufactured by Dowchemical. Density: 0.960g / cm 3 Melting point: 134℃, MFR: 0.8g / 10min • Linear low-density polyethylene (LLDPE) Product name: Elite5400G, manufactured by Dowchemical. Density: 0.916g / cm 3 Melting point: 123℃, MFR: 1.3g / 10min

[0167] <Polyethylene substrate> A mixture of 70 parts MDPE and 30 parts LLDPE was created, resulting in an average density of 0.934 g / cm³. 3 A blend of PE(A) was obtained. 70 parts MDPE and 30 parts HDPE were mixed to obtain an average density of 0.947 g / cm³. 3 Blended PE(B) was obtained. LLDPE, blended PE(A), and blended PE(B) were co-extruded in five layers by inflation molding with a layer thickness ratio of 15 μm for blended PE(B) layer, 22.5 μm for blended PE(A) layer, 50 μm for LLDPE layer, 22.5 μm for blended PE(A), and 15 μm for blended PE(B) layer to form a tubular film with a total thickness of 125 μm. The tubular film was folded at the nip and stacked in two. The obtained polyethylene film was stretched five times in the longitudinal direction (MD), and then one of the blended PE(B) layers was corona treated. The ends were then slit to separate it into two pieces, obtaining a polyethylene substrate (hereinafter also referred to as "PE substrate") with a thickness of 25 μm.

[0168] <Other stretched substrates> Ny substrate: Biaxially oriented nylon substrate with a thickness of 15 μm (Unitika, Emblem ON-RT) EVOH substrate: Biaxially oriented EVOH substrate with a thickness of 15 μm. (Kuraray, EVAL EF-XL)

[0169] [Production of sealant film] The following materials were used in the preparation of the sealant film. Medium-density polyethylene (MDPE) Product name: Elite5538G, manufactured by Dowchemical. Density: 0.941g / cm 3 Melting point: 129℃, MFR: 1.3g / 10min • Linear low-density polyethylene (LLDPE) Product name: Kernel KF260T, manufactured by Japan Polyethylene. Density: 0.901g / cm 3 Melting point: 93℃, MFR: 2.0g / 10min ·Adhesive resin Product name: Admar NF557, manufactured by Mitsui Chemicals. Maleic anhydride-modified polyethylene, density: 0.920 g / cm³ 3 • Ethylene-vinyl alcohol copolymer (EVOH) Product name: EVAL E171B, manufactured by Kuraray. Melting point: 165℃, Density: 1.14 g / cm³ 3 , MFR: 1.7g / 10min, Ethylene content: 44 mol% • Ethylene / α-olefin copolymer (hereinafter referred to as "Copolymer A") A copolymer of ethylene and C8 olefin, Density: 0.902g / cm 3 MFR: 1.0g / 10 minutes Polymerization catalyst: Metallocene catalyst • Ethylene / α-olefin copolymer (hereinafter referred to as "Copolymer B") A copolymer of ethylene and C8 olefin, Density: 0.918g / cm 3 , MFR:0.8g / 10min, Polymerization catalyst: Metallocene catalyst • Ethylene / α-olefin copolymer (hereinafter referred to as "Copolymer C") A copolymer of ethylene and C8 olefin, Density: 0.941g / cm 3 , MFR:1.3g / 10min, Polymerization catalyst: Metallocene catalyst • High-pressure low-density polyethylene (LDPE) Density: 0.919g / cm3 MFR: 2.0g / 10 minutes • Slip agent masterbatch (Slip agent MB) Base material: polyethylene, Slip agent: Erucic acid amide, Slip agent content: 2.0% by mass, Density: 0.921g / cm 3 MFR: 5.4g / 10 minutes • Antiblocking agent masterbatch (AB agent MB) Base material: polyethylene, antiblocking agent: acrylic resin, Antiblocking agent content: 30% by mass, Density: 0.959g / cm 3 MFR: 2.5g / 10 minutes

[0170] <EVOH-containing sealant film> A sealant film containing EVOH was obtained by co-extruding MDPE (Elite5538G), adhesive resin (Admer NF557), EVOH (EVAL E171B), adhesive resin (Admer NF557), and LLDPE (Kernel KF260T) using an inflation molding method. The EVOH-containing sealant film thus obtained comprises, in this order, a 45 μm thick MDPE layer, a 15 μm thick adhesive resin layer, a 10 μm thick EVOH layer, a 15 μm thick adhesive resin layer, and a 45 μm thick LLDPE layer. Corona treatment was performed on the MDPE (Elite5538G) layer surface.

[0171] <PE film (A)> A three-layer extrusion film was produced using a mixture of 93 parts by mass of copolymer A, 1 part by mass of slip agent MB, and 6 parts by mass of AB agent MB as the first layer (seal layer), a mixture of 69 parts by mass of copolymer C, 30 parts by mass of LDPE, and 1 part by mass of slip agent MB as the second layer (intermediate layer), and a mixture of 89 parts by mass of copolymer B, 10 parts by mass of LDPE, and 1 part by mass of slip agent MB as the second layer (laminate layer). The thickness ratio of the first layer (seal layer):second layer (intermediate layer):second layer (laminate layer) was 1:3:1, and a sealant film with a thickness of 130 μm (hereinafter also referred to as "PE film (A)") was obtained. Corona treatment was performed on the laminated surface of PE film (A).

[0172] The melting points of each layer in the obtained PE film (A) were determined using a differential scanning calorimeter in accordance with JIS K7121:2012, based on the following method. As a result, the melting point of the first layer (seal layer) was 99°C, the melting point of the second layer (intermediate layer) was 122°C, and the melting point of the second layer (laminate layer) was 117°C. The density of the first layer (seal layer) was 0.906 g / cm³. 3 The density of the second layer (intermediate layer) is 0.934 g / cm³. 3 The density of the second layer (laminate layer) is 0.918 g / cm³. 3 That was the case.

[0173] (Measurement of melting point) The melting points of each layer in the sealant film were determined using a differential scanning calorimeter in accordance with JIS K7121:2012. A Hitachi High-Tech Science TA7000 series thermal analyzer was used as the differential scanning calorimeter. Specifically, samples were taken from each layer of the sealant film. Approximately 10 mg of the sample was placed in an aluminum cell and heated under a nitrogen atmosphere at a rate of 10°C / min from 20°C to a temperature sufficiently higher than the melting point (e.g., 200°C). The sample was held at this temperature for 10 minutes, and then cooled to 20°C at a rate of 10°C / min. This heating, holding, and cooling process was repeated once more, and the melting peak temperature of the maximum endothermic peak observed during the second heating was determined and defined as the melting point.

[0174] <Other sealant films> PE film (B): Unstretched polyethylene film with a thickness of 130 μm (Mitsui Chemicals Tohcello, TUX-MCS)

[0175] [Adhesive] Use the following adhesive. Solvent-free adhesive (NSL): Manufactured by Rock Paint, a two-component curing urethane-based solvent-free adhesive. Main component: RN-920, hardener: HN-920 = 1:1 ratio. The weight-average molecular weight (Mw) of the polymer components in the main component was in the range of 2,000 to 2,500, and the polydispersity (Mw / Mn) of the polymer components in the main component was in the range of 2.0 to 2.5.

[0176] [Production of laminate] In the following descriptions of examples and comparative examples, detailed explanations of previously described layers (for example, layer formation conditions and thickness) may be omitted as appropriate.

[0177] [Example 1] A white layer with a thickness of 1 μm was formed by applying white ink to the corona-treated surface of a PE substrate using a gravure printing machine and drying it with hot air. A solvent-free adhesive was applied to the white layer surface of the substrate to form an adhesive layer with a thickness of 1 μm, and this adhesive layer surface was bonded to the corona-treated surface of an EVOH-containing sealant film. After bonding, an aging treatment was performed at 40°C for 4 days. A laminate was fabricated in the manner described above.

[0178] [Comparative Examples 1 to 3] A laminate was prepared in the same manner as in Example 1, except that the stretched substrate and sealant film used were those listed in Table 1, respectively.

[0179] [Production of standing pouch] Two of the resulting laminates were prepared, and the laminates were stacked so that the sealant layers faced each other. The two sides were then heat-sealed to form a body with a side seal (right) and a side seal (left). Next, another laminate was folded into a V-shape with the sealant layer facing outwards, sandwiched from one end of the body, and heat-sealed to form a bottom (bottom) with a bottom seal (front) and a bottom seal (back). In this way, a standing pouch was fabricated. The heat sealing conditions were a temperature of 140°C and a pressure of 1 kgf / cm². 2 , set to 1 second.

[0180] [Fragrance retention] 400 ml of the contents (softener) were filled into a standing pouch, and the opening was heat-sealed to seal it. The sealed standing pouch was then placed in an aluminum bag and cured for 5 days at 40°C and 90RH. Afterward, a panel test (N=10) was conducted to check the odor inside the aluminum bag, and the average score was calculated according to the following scoring criteria. An average score of 3.0 or higher was considered a passing grade. (Scoring criteria) 5: Odorless 4: A faint scent 3: Slight odor 2: A considerable smell 1: Smells similar to the contents

[0181] [Oxygen barrier property] The oxygen permeability of the laminate was measured using the following method. Using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20), the laminate was set with the sealant layer surface facing the oxygen supply side, and the oxygen permeability (unit: cc / m³) was measured in accordance with JIS K7126 under conditions of 23°C and 90% RH relative humidity. 2 The oxygen permeability (·day·atm) was measured. Two layers were tested (N=2), and the average of the obtained values ​​was defined as the oxygen permeability.

[0182] [Water vapor barrier property] The water vapor transmission rate of the laminate was measured by the following method: Using a water vapor transmission rate measuring device (MOCON, PERMATRAN-w 3 / 33), the laminate was set so that the sealant layer surface was on the water vapor supply side, and the water vapor transmission rate (unit: g / m³) was measured in accordance with JIS K7129 under conditions of 40°C and 90% RH relative humidity. 2 The water vapor permeability (day) was measured. Two tests (N=2) were conducted on two laminates, and the average of the obtained values ​​was defined as the water vapor permeability.

[0183] [Pressure resistance test] Each standing pouch was filled with air and sealed, then subjected to a load of 100 kgf x 1 minute to check for any rupture. Five standing pouches were tested (N=5).

[0184] [Drop test] Each standing pouch was filled with 400g of water and sealed. The pouches were then dropped from a height of 1m five times horizontally and five times vertically to check for rupture. Ten standing pouches were tested (N=10).

[0185] [Heat seal strength] A 15 mm wide test specimen was prepared from the heat-sealed portion of each standing pouch. The peel strength of the test specimen was measured in accordance with JIS Z1707. A Tensilon universal material tester RTC-1530 was used to measure the peel strength of the 15 mm wide specimen at a tensile speed of 300 mm / min. Measurements were performed on 5 test specimens (N=5), and the average value obtained was defined as the heat-seal strength.

[0186] [Tear strength] The tear strength of each laminate in the MD or TD direction was measured according to the Elmendorf tear test method of JIS K7128-2:1998. An Elmendorf tear tester (Tester Industries, IM-701) was used. Test specimens were prepared by stacking 16 laminates, and measurements were taken on 5 of these specimens (N=5). The average value obtained by converting the values ​​to a single-layer value was taken as the tear strength.

[0187] [Puncture strength] The puncture strength of the laminate was measured in accordance with "2. Strength Test Methods" of "Standards and Specifications for Foods, Additives, etc., Article 3: Utensils and Containers and Packaging" (Ministry of Health and Welfare Notification No. 20 of 1982) under the Food Sanitation Act. A needle with a diameter of φ1.0 mm × 0.5 mmR was used to puncture the laminate at a puncture speed of 50 mm / min, and the strength at which the needle penetrated the laminate was measured. Two types of puncture tests were performed: puncture from the stretched substrate (front) side and puncture from the sealant layer (back) side. Each test was performed 5 times (N=5), and the average value was calculated.

[0188] [Loop stiffness evaluation] A "DA-PC" manufactured by Toyo Seiki Seisakusho was used as the measuring device. The laminates obtained in the examples and comparative examples were cut to a size of 15 mm in width and 100 mm in length to obtain test specimens. Test specimens whose length direction is aligned with the MD of the laminate were described as "MD test specimens," and test specimens whose length direction is aligned with the TD of the laminate were described as "TD test specimens." Next, with the sealant layer of the test specimen facing inward, both ends of the test specimen were fixed by clipping, and a circular loop with a loop length of 60 mm was formed in the central part in the length direction. The obtained circular loop (width 15 mm × loop length 60 mm) was pressed from the opposite side of the clip at a pressing speed of 3.3 mm / second, and the measured value was taken as the loop stiffness value (mN). Measurements were performed on 5 test specimens (N=5), and the average value of the obtained values ​​was taken as the loop stiffness value.

[0189] [Heat seal curve] Two laminates were prepared, each cut to a size of 100mm x 100mm, and the sealant layer sides were placed facing each other and overlapped. One end was then heat-sealed using a heat sealing machine (Tester Industries, TP-701-A HEAT SEAL TESTER). The heat sealing conditions were: seal area 10mm x 100mm, sealing temperature 80℃~160℃ (single-sided heating), sealing pressure 1kgf / cm². 2The sealing time was set to 1 second. The sealed sample was cut to a width of 15 mm to prepare a test specimen with a length of 100 mm (MD direction), a width of 15 mm, and a heat-sealed portion of 10 mm x 15 mm. Tensile tests were performed on the obtained test specimens in accordance with JIS Z1707 using a tensile testing machine (Orientec, Tensilon Universal Material Testing Machine, RTC-1530) at 23°C and 50% RH. In the tensile test, the test specimen was opened 180° with the heat-sealed portion as the center, and both ends were attached to the tensile testing machine. The seal strength (N / 15 mm) was measured under the condition of a tensile speed of 300 mm / min. Measurements were performed on 5 test specimens (N=5), and the average value obtained was taken as the seal strength. If sealing was not possible due to thermal melting of the stretched substrate, it was recorded as "failure".

[0190] [Table 1] [Explanation of symbols]

[0191] 1. Barrier sealant film 2. Polyolefin layer 3 Adhesive resin layer 4. Barrier resin layer 5. Laminate 6 Adhesive layer 8 Stretched base material 10 packaging bags 11 Top 12 Lower part 12a Lower seal section 13 Side 13a Side seal portion 14 Surface film 15 Backside film 16 Lower film 17. Detention Unit 20 Spout part 20a Dispensing outlet seal 26 Easy-open line 28 Notches

Claims

1. Polyolefin layer, Barrier resin layer and A barrier sealant film comprising at least the following: The barrier sealant film is a co-extruded resin film comprising, in this order, a polyolefin layer containing linear low-density polyethylene as the main component, an adhesive resin layer, a barrier resin layer containing ethylene-vinyl alcohol copolymer or polyamide as the main component, an adhesive resin layer, and a polyolefin layer containing medium-density polyethylene as the main component. Barrier sealant film.

2. The barrier sealant film according to claim 1, wherein the thickness of the barrier resin layer is 1 μm or more and 30 μm or less.

3. A laminate comprising at least a stretched substrate and a sealant layer, The stretched substrate contains polyolefin as its main component, The sealant layer is a barrier sealant film according to claim 1 or 2. Laminated structure.

4. The laminate according to claim 3, wherein the laminate comprises an adhesive layer between the stretched substrate and the sealant layer.

5. The laminate according to claim 4, wherein the adhesive layer is an adhesive layer having a thickness of 0.1 μm or more and 2.0 μm or less.

6. The stretched substrate contains polyethylene as its main component, and the polyolefin layer of the barrier sealant film is a polyethylene layer. The laminate according to any one of claims 3 to 5.

7. The laminate according to any one of claims 3 to 6, wherein the polyolefin content in the entire laminate is 80% by mass or more.

8. A packaging bag comprising the laminate according to any one of claims 3 to 7.

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