Laminates, laminates for packaging materials, and packaging containers

Abstract

To provide a laminate that has a polypropylene resin substrate, a barrier substrate having a polypropylene resin layer and a vapor-deposition film, and a sealant layer containing polypropylene in this order in a thickness direction, wherein the laminate has improved gas barrier properties while maintaining recycling suitability.SOLUTION: A laminate has at least a polypropylene resin substrate, a barrier substrate, and a sealant layer in this order in a thickness direction, wherein the polypropylene resin substrate is a stretched substrate; the barrier substrate has at least an unstretched resin substrate having at least a polypropylene resin layer and a gas barrier resin layer, and a vapor-deposition film provided on the gas barrier resin layer; and the sealant layer is a resin layer containing polypropylene.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Traditionally, resin films made from resin materials have been used as packaging materials. For example, resin films made from polyolefins are widely used as packaging materials because they have moderate flexibility and transparency, as well as excellent heat-sealing properties.

[0003] Resin films made from polyolefins are generally inferior in terms of strength and heat resistance, and therefore cannot be used as a base material. Instead, they are used in combination with resin films made of polyester or polyamide. For this reason, typical packaging containers are made of laminated films in which the base material and sealant layer are made of different materials (for example, Patent Document 1).

[0004] In recent years, with the growing demand for a circular economy, there has been a need for packaging materials with high recyclability. However, conventional packaging containers are composed of different types of resin materials, making it difficult to separate them, and as a result, they are not actively recycled. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-202519 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present inventors considered using a stretched film of polypropylene as a base material instead of a conventional resin film made of polyester or polyamide, etc., and combining the base material with a sealant layer made of polypropylene. With such a configuration, since both the base material and the sealant layer are made of polypropylene, the recyclability of the packaging material can be improved. However, with such a configuration, the gas barrier property was not sufficient.

[0007] Therefore, the present inventors examined a laminate provided with a barrier base material having a polypropylene resin layer and a vapor-deposited film between the base material and the sealant layer. However, even with such a configuration, the gas barrier property was still not sufficient.

[0008] One of the problems to be solved by the present disclosure is to improve the gas barrier property while maintaining the recyclability in a laminate including a polypropylene resin base material, a barrier base material having a polypropylene resin layer and a vapor-deposited film, and a sealant layer containing polypropylene, in this order in the thickness direction.

Means for Solving the Problems

[0009] [[ID=1r4]] The laminate of the present disclosure includes at least a polypropylene resin base material, a barrier base material, and a sealant layer in this order in the thickness direction. The polypropylene resin base material is a stretched base material. The barrier base material includes at least an unstretched resin base material having at least a polypropylene resin layer and a gas barrier resin layer, and at least a vapor-deposited film provided on the gas barrier resin layer. The sealant layer is a resin layer containing polypropylene.

Effects of the Invention

[0010] According to the present disclosure, in the above laminate, the gas barrier property can be improved while maintaining the recyclability.

Brief Description of the Drawings

[0011] [Figure 1]FIG. 1 is a schematic cross-sectional view showing an embodiment of the laminate. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an embodiment of the laminate. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an embodiment of the laminate. [Figure 4] FIG. 4 is a perspective view showing an embodiment of the packaging container. [Figure 5] FIG. 5 is a perspective view showing an embodiment of the packaging container. **[Embodiments for Carrying Out the Invention]**

[0012] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms and is not to be construed as limited to the description of the embodiments exemplified below. For the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each layer as compared with the embodiments, but this is merely an example and does not limit the interpretation of the present disclosure. In this specification and each figure, elements that are the same as those already described with respect to the previously shown figures may be denoted by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0013] In the following description, each component that appears (for example, polypropylene, α-olefin, resin material, gas barrier resin, additive, metal, and inorganic oxide) may be used alone or in combination of two or more.

[0014] [Laminate] The laminate of the present disclosure includes at least a polypropylene resin base material, a barrier base material, and a sealant layer provided in this order in the thickness direction. The laminate of the present disclosure is suitable as a packaging material.

[0015] The polypropylene resin base material is a stretched base material, that is, a base material subjected to stretching treatment. The barrier substrate comprises at least an unstretched resin substrate having a polypropylene resin layer and a gas barrier resin layer, and a vapor-deposited film provided on the gas barrier resin layer. The sealant layer is a resin layer containing polypropylene.

[0016] By having polypropylene as the main component of the resin constituting the polypropylene resin substrate, the resin constituting the polypropylene resin layer, and the resin constituting the sealant layer, for example, the recyclability of the laminate can be improved.

[0017] The laminate 1 shown in Figure 1 comprises a polypropylene resin substrate 10, an adhesive layer 40A, a barrier substrate 20, an adhesive layer 40B, and a sealant layer 30, arranged in this order in the thickness direction. The barrier substrate 20 comprises an unstretched resin substrate 21 having a polypropylene resin layer 22 and a gas barrier resin layer 24, and a vapor-deposited film 25. In this example, the polypropylene resin layer 22 is in contact with the adhesive layer 40B, and the vapor-deposited film 25 is in contact with the adhesive layer 40A. In one embodiment, the laminate 1 further comprises a printed layer (not shown) on the polypropylene resin substrate 10. The printed layer is usually formed on the surface of the polypropylene resin substrate 10 that faces the sealant layer 30.

[0018] In the laminate 1 shown in Figure 2, the unstretched resin substrate 21 has an adhesive resin layer 23 between the polypropylene resin layer 22 and the gas barrier resin layer 24.

[0019] The laminate of this disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer. Compared to a laminate comprising only two elements, a barrier substrate and a sealant layer, the laminate of this disclosure exhibits superior gas barrier properties (particularly oxygen barrier properties and water vapor barrier properties). Furthermore, a laminate with such a configuration exhibits even higher gas barrier properties when subjected to heat treatment or the like, as the deposited film is adequately protected.

[0020] The polypropylene content in the entire laminate of this disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 88% by mass or more, and particularly preferably 90% by mass or more. This allows, for example, the production of monomaterial packaging containers using the laminate, thereby improving the recyclability of the packaging containers. There is no particular upper limit to the polypropylene content, but it may be, for example, 99% by mass or 95% by mass. The polypropylene content in the laminate refers to the ratio of the polypropylene content to the sum of the resin material content in each layer constituting the laminate.

[0021] <Polypropylene resin base material> The polypropylene resin substrate contains polypropylene as its main component, i.e., in an amount exceeding 50% by mass. By comprising the polypropylene resin substrate in the laminate of this disclosure, the oil resistance of, for example, packaging containers made using the laminate can be improved.

[0022] 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. As polypropylene, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used.

[0023] A propylene homopolymer is a polymer composed solely of propylene. A propylene random copolymer is a random copolymer of propylene and α-olefins other than propylene. A propylene block copolymer is a copolymer having polymer blocks made of propylene and polymer blocks made of α-olefins other than propylene.

[0024] 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.

[0025] Among polypropylenes, propylene random copolymer is preferable from the viewpoint of transparency. When rigidity and heat resistance of the packaging container are important, propylene homopolymer is preferable. When impact resistance of the packaging container is important, propylene block copolymer is preferable.

[0026] The melt flow rate (MFR) of polypropylene may be between 0.1 g / 10 min and 50 g / 10 min, or between 0.3 g / 10 min and 30 g / 10 min, from the viewpoint of film-forming properties and processability. In this disclosure, the MFR of polypropylene is measured in accordance with ASTM D1238, under conditions of a temperature of 230°C and a load of 2.16 kg.

[0027] Polypropylene resin substrates can be produced, for example, by forming a film from polypropylene using a T-die method or an inflation method, and then stretching the film. The inflation method allows for simultaneous film formation and stretching.

[0028] The polypropylene content in the polypropylene resin substrate is more than 50% by mass, preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0029] The polypropylene resin substrate may contain resin materials other than polypropylene. Examples of such resin materials include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

[0030] Polypropylene resin substrates may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0031] The polypropylene resin substrate is a substrate that has undergone a stretching treatment. This can improve, for example, the strength, heat resistance, and transparency of the laminate. The stretching treatment may be uniaxial stretching or biaxial stretching.

[0032] When stretching in the longitudinal direction (the direction of substrate flow, MD direction), the stretching ratio is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. By setting the stretching ratio to 2 times or more, for example, the strength, heat resistance and transparency of the polypropylene resin substrate can be improved, and the printability of the polypropylene resin substrate can also be improved. From the viewpoint of the breaking limit of the polypropylene resin substrate, a stretching ratio of 10 times or less is preferable.

[0033] In one embodiment, the polypropylene resin substrate may be surface-treated. This can improve, for example, the adhesion between the polypropylene resin substrate and other layers. Examples of surface treatment methods include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, and glow discharge treatment; and chemical treatments such as oxidation treatment using chemicals. An easy-adhesion layer may be provided on the surface of the polypropylene resin substrate.

[0034] The polypropylene resin substrate may have a single-layer structure or a multi-layer structure. The thickness of the polypropylene resin substrate is preferably 5 μm to 300 μm, more preferably 8 μm to 100 μm, and even more preferably 10 μm to 50 μm. If the thickness is above the lower limit, for example, the strength and heat resistance of the laminate can be improved. If the thickness is below the upper limit, for example, the processability of the laminate can be improved.

[0035] The laminate of this disclosure may have a printed layer on the surface of a polypropylene resin substrate. Examples of images formed in the printed layer include letters, patterns, symbols, and combinations thereof. The printed layer may be formed using, for example, biomass-derived ink. This can, for example, further reduce the environmental impact.

[0036] The printed layer may be formed on any surface of the polypropylene resin substrate. Preferably, the printed layer is formed on the surface of the polypropylene resin substrate that is on the sealant layer side, as this suppresses contact between the printed layer and the outside air and suppresses deterioration of the printed layer over time.

[0037] Conventional printing methods such as gravure printing, offset printing, and flexographic printing can be used to form the printed layer. Among these, flexographic printing is preferred from the viewpoint of reducing environmental impact.

[0038] <Barrier substrate> The barrier substrate comprises an unstretched resin substrate and a vapor-deposited film. The resin substrate comprises a polypropylene resin layer and a gas barrier resin layer. By including the resin substrate in the laminate of this disclosure, for example, its strength, oxygen barrier properties, and water vapor barrier properties can be improved. The resin substrate may further include an adhesive resin layer between the polypropylene resin layer and the gas barrier resin layer. This can, for example, further improve the adhesion between these layers.

[0039] The vapor-deposited film is provided on a gas barrier resin layer. In one embodiment, the barrier substrate comprises a polypropylene resin layer, optionally an adhesive resin layer, a gas barrier resin layer, and a vapor-deposited film, in this order in the thickness direction.

[0040] In the barrier substrate, it is preferable that the vapor-deposited film faces the polypropylene resin substrate side and the polypropylene resin layer faces the sealant layer side.

[0041] (Polypropylene resin layer) The polypropylene resin layer contains polypropylene as its main component, i.e., in an amount exceeding 50% by mass. By including the polypropylene resin layer in the barrier substrate, the oil resistance of packaging containers made using the barrier substrate can be improved, for example.

[0042] Polypropylene may be propylene homopolymer, propylene random copolymer, or propylene block copolymer, or a mixture of two or more selected from these. As polypropylene, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used. Further details are as described above.

[0043] Among polypropylenes, propylene homopolymer or propylene random copolymer is preferable from the viewpoint of transparency. When rigidity and heat resistance of the packaging container are important, propylene homopolymer is preferable. When impact resistance of the packaging container is important, propylene random copolymer is preferable.

[0044] The density of polypropylene is, for example, 0.88 g / cm³. 3 More than 0.92g / cm 3 The following applies: In this disclosure, density is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C).

[0045] From the viewpoint of film-forming properties and processability, the polypropylene MFR is preferably 0.1 g / 10 min to 50 g / 10 min, more preferably 0.3 g / 10 min to 30 g / 10 min, and even more preferably 0.5 g / 10 min to 20 g / 10 min.

[0046] When producing a resin substrate by the T-die method, the polypropylene MFR is preferably 5.0 g / 10 min to 20 g / 10 min. If the MFR is above the lower limit, for example, the processability of the laminate can be improved. If the MFR is below the upper limit, for example, the breakage of the resin film can be suppressed.

[0047] When producing a resin substrate by the inflation method, the polypropylene MFR is preferably 0.5 g / 10 min to 5.0 g / 10 min. If the MFR is above the lower limit, for example, the processability of the laminate can be improved. If the MFR is below the upper limit, for example, the film-forming properties can be improved.

[0048] The polypropylene content in the polypropylene resin layer is more than 50% by mass, preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0049] The polypropylene resin layer may contain resin materials other than polypropylene. Examples of such resin materials include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins. The polypropylene resin layer may contain the above-mentioned additives.

[0050] In one embodiment, the polypropylene resin layer may be subjected to the above-described surface treatment. This can, for example, improve the adhesion between the polypropylene resin layer and other layers. An easy-adhesion layer may be provided on the surface of the polypropylene resin layer.

[0051] The polypropylene resin layer may have a single-layer structure or a multi-layer structure. When the polypropylene resin layer has a multilayer structure, the number of polypropylene resin layers is, for example, 2 to 7 layers, preferably 3 to 5 layers. In one embodiment, the polypropylene resin layer comprises a first layer made of random polypropylene, a second layer made of homopolypropylene, and a third layer made of random polypropylene. This makes it possible to improve the balance of rigidity, heat resistance, and impact resistance of the packaging container, for example.

[0052] The ratio of the first thickness to the total thickness of the polypropylene resin layer is preferably 3% to 30%, more preferably 5% to 20%, and even more preferably 8% to 15%. The ratio of the second thickness to the total thickness of the polypropylene resin layer is preferably 40% to 94%, more preferably 60% to 90%, and even more preferably 70% to 84%. The ratio of the third thickness to the total thickness of the polypropylene resin layer is preferably 3% to 30%, more preferably 5% to 20%, and even more preferably 8% to 15%.

[0053] The thickness of the polypropylene resin layer is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm. If the polypropylene resin layer has a multilayer structure, it is preferable that its total thickness be within the above range. If the thickness is above the lower limit, for example, the strength, heat resistance, and recyclability of the laminate can be improved. If the thickness is below the upper limit, for example, the processability of the laminate can be improved.

[0054] The barrier substrate may have a printed layer on the surface of the polypropylene resin layer. Examples of images formed in the printed layer include letters, patterns, symbols, and combinations thereof. The printed layer may be formed using, for example, biomass-derived ink. This can further reduce the environmental impact. The method for forming the printed layer is as described above.

[0055] (Gas barrier resin layer) The barrier substrate comprises a gas barrier resin layer between the polypropylene resin layer and the vapor-deposited film. This configuration allows for improved adhesion of the vapor-deposited film and enhanced gas barrier properties.

[0056] The gas barrier resin layer contains a gas barrier resin. Examples of gas barrier resins include polyamides such as nylon 6, nylon 6,6 and polymethoxyylene adipamide, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyacrylonitrile, polyester, polyurethane, and (meth)acrylic resins. Among these, polyamides and ethylene-vinyl alcohol copolymers are preferred from the viewpoint of oxygen barrier properties and water vapor barrier properties.

[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] Specifically, the semi-aromatic polyamides include polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6I), polynonamethylene 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 lidodecamid 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] In one embodiment, the gas barrier resin layer contains a crystalline aliphatic polyamide. Examples of crystalline aliphatic polyamides include PA6, PA11, PA12, PA66, PA610, PA612, PA6 / 66, and PA6 / 66 / 12.

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

[0067] In ethylene-vinyl alcohol copolymers (EVOH), the content of ethylene-derived constituent units (ethylene content) is preferably 20 mol% to 60 mol%, more preferably 25 mol% to 50 mol%. If the ethylene content is above the lower limit, for example, the processability of the laminate can be improved. If the ethylene content is below the upper limit, for example, the oxygen barrier and water vapor barrier properties of the laminate can be improved. The ethylene content is measured by NMR spectroscopy.

[0068] The melting point (Tm) of EVOH is preferably 130°C to 200°C, more preferably 140°C to 195°C, and even more preferably 150°C to 190°C.

[0069] The melt flow rate (MFR) of EVOH is preferably 0.1 g / 10 min to 30 g / 10 min, more preferably 0.3 g / 10 min to 20 g / 10 min, and even more preferably 0.5 g / 10 min to 10 g / 10 min, 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, although the measurement temperature may be 210°C depending on the melting point of EVOH.

[0070] The difference between the melting point of the gas barrier resin contained in the gas barrier resin layer and the melting point of the polypropylene contained in the polypropylene resin layer is preferably 100°C or less, more preferably 80°C or less, and even more preferably 70°C or less. When the above difference is below the upper limit, for example, the film-forming properties of the resin substrate can be improved.

[0071] The gas barrier resin content in the gas barrier resin layer is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, 85% by mass or more, or 90% by mass or more. This improves, for example, the oxygen barrier properties and water vapor barrier properties of the laminate.

[0072] The gas barrier resin layer may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, compatibilizers, and pigments.

[0073] The thickness of the gas barrier resin layer is preferably 0.5 μm to 10 μm, more preferably 1.0 μm to 5.0 μm. If the thickness is above the lower limit, for example, the oxygen barrier and water vapor barrier properties of the laminate can be improved. If the thickness is below the upper limit, for example, the recyclability of the laminate can be improved.

[0074] In one embodiment, the thickness of the gas barrier resin layer is preferably smaller than the thickness of the polypropylene resin layer. This can improve, for example, the recyclability of the laminate. The thickness of the gas barrier resin layer is preferably 5 μm or more smaller than the thickness of the polypropylene resin layer, and more preferably 10 μm or more smaller.

[0075] (adhesive resin layer) The resin substrate may include an adhesive resin layer between the polypropylene resin layer and the gas barrier resin layer. This can improve, for example, the adhesion between the polypropylene resin layer and the gas barrier resin layer.

[0076] The adhesive resin layer contains a resin material. Examples of resin materials include polyolefins, modified polyolefins, vinyl resins, polyethers, polyesters, polyamides, 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.

[0077] 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.

[0078] The melt flow rate (MFR) of modified polyolefins is preferably 0.1 g / 10 min to 50 g / 10 min, more preferably 0.3 g / 10 min to 30 g / 10 min, even more preferably 0.5 g / 10 min to 10 g / 10 min, and particularly preferably 0.5 g / 10 min to 5.0 g / 10 min, 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.

[0079] The adhesive resin layer may contain the above-mentioned additives.

[0080] The thickness of the adhesive resin layer is preferably 0.5 μm to 10 μm, more preferably 1.0 μm to 7.0 μm. 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.

[0081] In one embodiment, the resin substrate is an unstretched co-extruded resin film. In one embodiment, the resin substrate is an unstretched resin film obtained by co-extruding a material constituting a polypropylene resin layer, a material constituting an adhesive resin layer if the resin substrate has an adhesive resin layer, and a material constituting a gas barrier resin layer using a conventionally known method such as the T-die method or the inflation method.

[0082] (Vaporized film) The barrier substrate comprises a vapor-deposited film on a gas barrier resin layer of a resin substrate. By providing a vapor-deposited film on the gas barrier resin layer, for example, the gas barrier properties of the laminate of this disclosure, specifically the oxygen barrier properties and water vapor barrier properties, can be improved. Furthermore, if the vapor-deposited film is a metal vapor-deposited film, the brightness can be improved. A packaging container made using the laminate can suppress the mass reduction of the contents filled inside the packaging container.

[0083] The vapor-deposited film is composed of metals such as aluminum, chromium, tin, nickel, copper, silver, gold, and platinum; or inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, and silicon carbide oxide (carbon-containing silicon oxide). Among these, aluminum vapor-deposited films, aluminum oxide (alumina) vapor-deposited films, silicon oxide (silica) vapor-deposited films, or silicon carbide oxide vapor-deposited films are preferred.

[0084] The thickness of the vapor-deposited film is preferably 1 nm to 150 nm, more preferably 5 nm to 100 nm, and even more preferably 10 nm to 80 nm. If the thickness is above the lower limit, for example, the oxygen barrier and water vapor barrier properties of the laminate can be improved. If the thickness is below the upper limit, for example, the occurrence of cracks in the vapor-deposited film can be suppressed, and the recyclability of the packaging container can be improved.

[0085] When the vapor deposition film is an aluminum vapor deposition film, the optical density (OD value) of the aluminum vapor deposition film is preferably 2.0 or more and 3.5 or less. Thereby, for example, while maintaining the productivity of the laminate, the oxygen barrier property and the water vapor barrier property can be improved. The OD value can be measured in accordance with JIS K7361.

[0086] It is preferable that the above surface treatment is performed on the surface of the vapor deposition film. Thereby, for example, the adhesion between the vapor deposition film and the adjacent layer can be improved.

[0087] Examples of the method for forming the vapor deposition film include physical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as vacuum vapor deposition method, sputtering method, and ion plating method, and chemical vapor deposition methods (Chemical Vapor Deposition method, CVD method) such as plasma chemical vapor deposition method, thermal chemical vapor deposition method, and photo chemical vapor deposition method. The vapor deposition film may be a composite film including two or more layers of different vapor deposition films formed by using both physical vapor deposition method and chemical vapor deposition method in combination.

[0088] As the degree of vacuum in the vapor deposition chamber, before introducing oxygen, it is preferably about 10 -2 ~10 -8 mbar, and after introducing oxygen, it is preferably about 10 -1 ~10 -6 mbar. The amount of oxygen introduced etc. varies depending on the size of the vapor deposition machine etc. For the introduced oxygen, inert gases such as argon gas, helium gas, and nitrogen gas may be used as carrier gases within a non-obstructive range. The conveyance speed of the target film on which the vapor deposition film is formed is, for example, 10 m / min or more and 800 m / min or less.

[0089] The vapor deposition film may be a single layer formed by one vapor deposition process, or may be a multilayer formed by a plurality of vapor deposition processes. When the vapor deposition film is a multilayer, each layer may be composed of the same component, or may be composed of different components. Each layer may be formed by the same method, or may be formed by different methods.

[0090] (Barrier coat layer) In one embodiment, the barrier substrate may further comprise a barrier coating layer on the vapor-deposited film. That is, the barrier substrate may further comprise a barrier coating layer on the surface of the vapor-deposited film opposite to the surface facing the polypropylene resin layer. This can improve, for example, the oxygen barrier properties and water vapor barrier properties of the laminate. Furthermore, if the vapor-deposited film is composed of inorganic oxides such as aluminum oxide and silicon oxide, the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0091] In one embodiment, the barrier coat layer contains a gas barrier resin. Examples of gas barrier resins include ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyamides such as nylon 6, nylon 6,6 and polymethoxyylene adipamide, polyurethane, and (meth)acrylic resins.

[0092] The gas barrier resin content in the barrier coat layer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. With this configuration, for example, the gas barrier properties of the barrier coat layer can be improved. The barrier coat layer may contain the above-mentioned additives.

[0093] The thickness of the barrier coating layer containing the gas barrier resin is preferably 0.01 μm to 10 μm, more preferably 0.1 μm to 5.0 μm. If the thickness is above the lower limit, for example, the gas barrier properties can be improved. If the thickness is below the upper limit, for example, the processability of the laminate and the recyclability of the packaging container can be improved.

[0094] The barrier coating layer can be formed, for example, by applying and drying a coating solution obtained by dissolving or dispersing a material such as a gas barrier resin in water or a suitable organic solvent.

[0095] In another embodiment, the barrier coat layer is a gas barrier coating film formed by applying a gas barrier composition obtained by mixing a metal alkoxide, a water-soluble polymer, and optionally a silane coupling agent, and optionally adding water, an organic solvent, and a sol-gel catalyst, onto a vapor-deposited film and drying it. The gas barrier coating film contains hydrolyzed polycondensates obtained by hydrolysis and polycondensation of the above-mentioned metal alkoxide, etc., by the sol-gel method. By providing such a barrier coat layer on a vapor-deposited film, when the vapor-deposited film is composed of inorganic oxides, the occurrence of cracks in the vapor-deposited film can be effectively suppressed.

[0096] Metal alkoxides are represented, for example, by formula (1). R 1 n M(OR 2 ) m (1) In formula (1), R 1 and R 2 Each of these independently represents an organic group with 1 to 8 carbon atoms, M represents a metal atom, n represents an integer greater than or equal to 0, m represents an integer greater than or equal to 1, and n+m represents the valence of M.

[0097] R 1 and R 2 Examples of organic groups in this context include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-hexyl, and n-octyl groups. The metal atom M is, for example, silicon, zirconium, titanium, or aluminum.

[0098] Examples of metal alkoxides include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0099] Examples of water-soluble polymers include hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Depending on the desired physical properties such as oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated. The amount of water-soluble polymer used is preferably 5 to 500 parts by mass per 100 parts by mass of metal alkoxide.

[0100] As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, and organoalkoxysilanes having an epoxy group are preferred, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The amount of silane coupling agent used is preferably 1 to 20 parts by mass per 100 parts by mass of metal alkoxide.

[0101] The gas barrier composition may contain water in a ratio of preferably 0.1 moles to 100 moles, more preferably 0.5 moles to 60 moles, per mole of metal alkoxide. By setting the water content above the lower limit, for example, the oxygen barrier and water vapor barrier properties of the laminate can be improved. By setting the water content below the upper limit, for example, hydrolysis reactions can be carried out rapidly.

[0102] The gas barrier composition may contain an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0103] Acids or amine compounds are preferred as catalysts for the sol-gel method. Examples of acids include mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid; and organic acids such as acetic acid and tartaric acid. The amount of acid used is preferably 0.001 moles or more and 0.05 moles or less per mole of the total molar amount of the metal alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent.

[0104] Suitable amine compounds include tertiary amines that are substantially insoluble in water and soluble in organic solvents, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. The amount of amine compound used is preferably 0.01 parts by mass or more and 1.0 part by mass or less, and more preferably 0.03 parts by mass or more and 0.3 parts by mass or less, per 100 parts by mass of the total amount of the metal alkoxide and silane coupling agent.

[0105] Methods for applying the gas barrier composition include, for example, roll coating such as gravure roll coaters, spray coating, spin coating, dipping, brushing, bar coating, and application methods such as applicators.

[0106] The following describes one embodiment of a method for forming a gas barrier coating film. A gas barrier composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent. A polycondensation reaction gradually proceeds within the composition. The composition is applied to a vapor-deposited film by a conventional method and dried. This drying further promotes the polycondensation of the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains one), forming a composite polymer layer. Multiple composite polymer layers may be laminated by repeating the above operation. For example, the applied composition is heated at a temperature preferably between 20°C and 150°C, more preferably between 50°C and 120°C, and even more preferably between 70°C and 100°C for 1 second to 10 minutes. This forms a gas barrier coating film.

[0107] The thickness of the gas barrier coating film is preferably 0.01 μm to 100 μm, more preferably 0.1 μm to 50 μm, and even more preferably 0.1 μm to 5.0 μm. This allows for improved gas barrier properties, suppression of crack formation in vapor-deposited films composed of inorganic oxides, and improved recyclability and processability of packaging containers.

[0108] <Sealant layer> The laminate of this disclosure comprises a sealant layer. The sealant layer is a resin layer containing polypropylene. The sealant layer is composed of a polypropylene resin base material and a resin material of the same type as the polypropylene resin layer, i.e., polypropylene. This makes it possible to create a monomaterial packaging container. After collecting used packaging containers, there is no need to separate the base material and the sealant layer, improving the recyclability of the packaging containers. By composing the sealant layer with polypropylene, the oil resistance of packaging containers made using laminates can also be improved.

[0109] The polypropylene content in the sealant layer is preferably more than 50% by mass, more preferably 70% by mass or more, and even more preferably 75% by mass or more. This can improve, for example, the recyclability of the packaging container.

[0110] Examples of polypropylene include propylene homopolymers, propylene random copolymers such as propylene-α-olefin random copolymers, and propylene block copolymers such as propylene-α-olefin block copolymers. Details of α-olefins are as described above. From the viewpoint of reducing environmental impact, biomass-derived polypropylene and / or recycled polypropylene may be used.

[0111] The density of polypropylene, from the perspective of heat sealability, is, for example, 0.88 g / cm³. 3 More than 0.92g / cm 3The following applies: In this disclosure, density is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C).

[0112] From the viewpoint of film-forming properties and processability, the polypropylene MFR is preferably 0.1 g / 10 min to 50 g / 10 min, more preferably 0.3 g / 10 min to 30 g / 10 min, and even more preferably 0.5 g / 10 min to 20 g / 10 min.

[0113] When producing a sealant layer by the T-die method, the polypropylene MFR is preferably 5.0 g / 10 min to 20 g / 10 min. If the MFR is above the lower limit, for example, the processability of the sealant layer can be improved. If the MFR is below the upper limit, for example, the rupture of the sealant layer can be suppressed.

[0114] When producing a sealant layer by the inflation method, the polypropylene MFR is preferably 0.5 g / 10 min to 5.0 g / 10 min. If the MFR is above the lower limit, for example, the processability of the sealant layer can be improved. If the MFR is below the upper limit, for example, the film-forming properties can be improved.

[0115] The sealant layer may contain the above-mentioned additives.

[0116] The sealant layer may contain a heat seal modifier to improve low-temperature heat sealability. The heat seal modifier is not particularly limited as long as it is a component that has excellent compatibility with the polypropylene constituting the sealant layer, but examples include olefin polymers with low melting points, specifically olefin copolymers.

[0117] The melting point (Tm) of the olefin copolymer used as a heat seal modifier is preferably 115°C or lower, more preferably 110°C or lower, and even more preferably 105°C or lower, from the viewpoint of improving heat sealability. The lower limit of Tm is not particularly limited, but for example, it is 50°C, 60°C, or 70°C. In this disclosure, Tm is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0118] The olefin copolymer is not particularly limited as long as it is compatible with polypropylene and has a low melting point; examples include olefin elastomers and olefin plastomers.

[0119] Examples of olefin-based elastomers include ethylene-α-olefin copolymers. Examples of α-olefins include α-olefins with 4 to 8 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene.

[0120] Plastomer is a term used in contrast to elastomer (a polymer that deforms in accordance with an external force when that force is applied, and returns to its original shape in a short time when that force is removed). Plastomer is a polymer that does not exhibit elastic deformation like elastomers, but rather undergoes plastic deformation easily.

[0121] Examples of olefin-based plastomers include polyethylene-based plastomers. Polyethylene-based plastomers are polyethylene obtained by copolymerizing ethylene and α-olefins using a single-site catalyst such as a metallocene catalyst. Preferred α-olefins include α-olefins with 4 to 8 carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Specific examples of polyethylene-based plastomers include ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer.

[0122] The density of the olefin copolymer is preferably 0.850 g / cm³.3 More than 0.920g / cm 3 More preferably, 0.860 g / cm³ 3 More than 0.915g / cm 3 More preferably, 0.870 g / cm³ 3 More than 0.910g / cm 3 The following applies:

[0123] The MFR of olefin copolymers is preferably 0.2 g / 10 min to 20 g / 10 min, more preferably 0.3 g / 10 min to 15 g / 10 min, and even more preferably 0.5 g / 10 min to 10 g / 10 min, from the viewpoint of film-forming properties and processability. The MFR of olefin copolymers is measured in accordance with ASTM D1238, under conditions of a temperature of 190°C and a load of 2.16 kg.

[0124] The proportion of the heat seal modifier in the entire sealant layer is preferably 5% to 40% by mass, more preferably 10% to 30% by mass. This allows for, for example, the sealant layer to be given suitable heat sealability.

[0125] The thickness of the sealant layer is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm. If the thickness is above the lower limit, for example, the heat sealability of the sealant layer and the recyclability of the packaging container can be improved. If the thickness is below the upper limit, for example, the processability of the laminate can be improved.

[0126] The sealant layer may have a single-layer structure or a multi-layer structure. In one embodiment, a multilayer sealant layer comprises a first sealant layer containing polypropylene and a second sealant layer containing polypropylene and a heat seal modifier. Here, the sealant layers are arranged such that the first sealant layer is located closer to the barrier substrate than the second sealant layer. With this configuration, for example, it is possible to achieve both low-temperature heat sealability and processability.

[0127] The polypropylene content in the first sealant layer is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0128] The content of the heat seal modifier in the second sealant layer is preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 45% by mass or less. If the content is above the lower limit, for example, the heat sealability of the second sealant layer can be improved. If the content is below the upper limit, for example, the recyclability of the laminate can be improved. The content of polypropylene in the second sealant layer is preferably 50% by mass or more and 90% by mass or less, more preferably 55% by mass or more and 80% by mass or less.

[0129] The thickness of the first sealant layer is preferably 5 μm to 50 μm, more preferably 10 μm to 30 μm, and even more preferably 10 μm to 20 μm. If the thickness is above the lower limit, for example, the recyclability of the laminate and the heat sealability of the first sealant layer can be improved. If the thickness is below the upper limit, for example, the processability of the laminate can be improved.

[0130] The thickness of the second sealant layer is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm, and even more preferably 10 μm to 30 μm. If the thickness is above the lower limit, for example, the heat sealability of the second sealant layer can be improved. If the thickness is below the upper limit, for example, both the recyclability and processability of the laminate can be achieved.

[0131] From the viewpoint of heat sealability, the sealant layer 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 a casting method, a T-die method, or an inflation method.

[0132] For example, an unstretched resin film corresponding to the sealant layer may be laminated onto a barrier substrate via an adhesive layer as needed, or the sealant layer may be formed by melt-extruding polypropylene or a resin composition thereof onto the barrier substrate. Examples of adhesive layers include those described later.

[0133] The laminate of this disclosure may further include a vapor-deposited film on the surface of the sealant layer facing the polypropylene resin substrate (see vapor-deposited film 32 in Figure 3). This can further improve the gas barrier properties of the laminate, for example. Details of the vapor-deposited film are as described above and will not be explained here.

[0134] <Adhesive layer> In one embodiment, the laminate of the present disclosure comprises a first adhesive layer between a polypropylene resin substrate and a barrier substrate. In one embodiment, the laminate of the present disclosure comprises a second adhesive layer between the barrier substrate and a sealant layer. This can improve, for example, the adhesion between these layers.

[0135] The adhesive layer is composed of an adhesive, which 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. The laminate of this disclosure comprises at least three elements: a polypropylene resin substrate, a barrier substrate, and a sealant layer. This makes it possible to manufacture the laminate using an adhesive without directly applying the adhesive to the vapor-deposited film, thereby suppressing the degradation of the vapor-deposited film.

[0136] Examples of adhesives include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, urethane-based adhesives, rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, and phenol-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing type urethane-based adhesives are more preferred.

[0137] The thickness of the adhesive layer is, for example, 0.1 μm or more and 10 μm or less, preferably 0.2 μm or more and 8.0 μm or less, more preferably 0.5 μm or more and 6.0 μm or less, and even more preferably 0.8 μm or more and 5.0 μm or less.

[0138] The adhesive layer can be formed by applying an adhesive to an object and drying it using conventionally known methods such as the direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fontein method, and transfer roll coating method.

[0139] In one embodiment, the laminate of the present disclosure may be manufactured by laminating a polypropylene resin substrate, a barrier 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] [Packaging container] The laminates of this disclosure can be suitably used for packaging material applications. The packaging material is used to manufacture a packaging container. The packaging material comprises the laminate of the present disclosure. A packaging container can be manufactured by using at least the packaging material comprising the laminate of the present disclosure.

[0141] The packaging containers of this disclosure comprise the laminates of this disclosure. Examples of packaging containers include packaging bags, tube containers, and containers with lids. A container with a lid comprises a container body having a storage compartment and a lid material joined (heat-sealed) to the container body to seal the storage compartment.

[0142] Examples of heat sealing methods include bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals.

[0143] Examples of packaging bags include various types such as standing pouch type, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope seal type, gusset seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.

[0144] The packaging container may be equipped with an easy-open section. Examples of easy-open sections include a notch that serves as the starting point for tearing the packaging container, and a half-cut line formed by laser processing or a cutter as a path when tearing the packaging container.

[0145] The packaging container may be equipped with a steam venting mechanism. The steam venting mechanism is configured to allow steam to escape by connecting the inside and outside of the packaging container when the steam pressure inside the packaging container exceeds a predetermined value, while also preventing steam from escaping from other parts of the container.

[0146] The steam venting mechanism includes, for example, a steam venting seal protruding inward from the side seal portion of the packaging container, and an unsealed portion isolated from the contents storage portion by the steam venting seal portion. The unsealed portion communicates with the outside of the packaging container. The packaging container, filled with contents and with its opening heat-sealed, is heated using a microwave oven or the like. This increases the internal pressure, causing the steam venting seal portion to detach. Steam escapes to the outside of the packaging container through the detached steam venting seal portion and the unsealed portion.

[0147] In one embodiment, a packaging bag can be made by folding the laminate of the present disclosure in half so that the polypropylene resin substrate is on the outside and the sealant layer is on the inside, overlapping the two halves, and then heat-sealing the edges. In another embodiment, a packaging bag can be made by overlapping multiple laminates of the present disclosure so that the sealant layers face each other, and then heat-sealing the edges. The entire packaging bag may be made of the above laminate, or only a part of the packaging bag may be made of the above laminate. Figure 4 shows an example of a packaging bag. In the figure, the shaded area represents the heat-sealed portion.

[0148] In one embodiment, the laminate of the present disclosure is used as a lid material in a container with a lid. The container with a lid comprises a container body having a storage compartment and a lid material joined (heat-sealed) to the container body so as to seal the storage compartment. Here, the lid material, i.e., the sealant layer of the laminate, and the container body are heat-sealed. Examples of container body shapes include cup shape and bottomed cylindrical shape. The container body is made of, for example, polystyrene, polypropylene, polyethylene, or paper.

[0149] Examples of contents that can be contained in the packaging container include liquids, solids, powders, and gels. The contents may be food or beverages, or non-food items such as chemicals, cosmetics, and pharmaceuticals. After the contents are placed in the packaging container, the container can be sealed by heat-sealing the opening.

[0150] As specific examples of packaging bags, small bags and standing pouches will be described below. A small pouch is a small packaging bag used to contain contents weighing, for example, 1g to 200g. Examples of contents that can be contained in a small pouch include sauces, soy sauce, dressings, ketchup, syrups, cooking alcoholic beverages, other liquid or viscous seasonings; liquid soups, powdered soups, fruit juices; spices; liquid beverages, jelly beverages, instant foods, and other food and beverages. The laminate of this disclosure is suitable as a packaging material for making small pouches.

[0151] Standing pouches are used to contain contents ranging from 50g to 2000g. Examples of contents that can be contained in standing pouches include shampoo, rinse, conditioner, hand soap, body soap, fragrances, deodorizers, insect repellents, detergents; dressings, cooking oils, mayonnaise, and other liquid or viscous condiments; liquid beverages, jelly beverages, instant foods, and other food and beverages; and creams.

[0152] In one embodiment, a standing pouch comprises a body (side sheet) and a bottom (bottom sheet). The side sheet and the bottom sheet may be made of the same material or of different materials. The bottom sheet maintains the shape of the side sheet, thereby giving the pouch self-supporting properties and enabling it to be a standing pouch. A storage space for containing contents is formed within the area enclosed by the side sheet and the bottom sheet.

[0153] The standing pouch may be equipped with a steam venting mechanism. The steam venting mechanism comprises a steam venting seal portion that protrudes inward from the side seal portion towards the inside of the packaging container, and an unsealed portion isolated from the contents storage portion by the steam venting seal portion. The unsealed portion is in communication with the outside of the packaging container.

[0154] In a standing pouch, the body may be made only of the laminate of the Disclosure, the bottom may be made only of the laminate of the Disclosure, or both the body and the bottom may be made of the laminate of the Disclosure.

[0155] In one embodiment, the side sheet can be formed by manufacturing a bag such that the sealant layer of the laminate of the present disclosure is the innermost layer. In another embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them so that the sealant layers face each other, and heat-sealing the side edges on both sides to form a bag.

[0156] In another embodiment, the side sheet can be formed by preparing two laminates of the present disclosure, overlapping them so that the sealant layers face each other, and inserting two V-shaped folded laminates with the sealant layers facing outwards into the gaps between the laminates at the side edges on both sides of the overlapped laminates, and then heat-sealing them. According to this manufacturing method, a standing pouch having a body with side gussets can be obtained. An example of a standing pouch is shown in Figure 5. In the figure, the shaded area represents the heat-sealed portion.

[0157] In one embodiment, the bottom sheet can be formed by inserting the laminate of the present disclosure between the lower parts of the bag-formed side sheets and heat-sealing it. More specifically, the bottom sheet can be formed by inserting a laminate folded in a V-shape with the sealant layer facing outwards between the lower parts of the bag-formed side sheets and heat-sealing it.

[0158] In one embodiment, two of the above-mentioned laminates are prepared and stacked so that the sealant layers face each other. Then, the other laminate is folded into a V-shape so that the sealant layer faces outwards, and this is sandwiched between the bottoms of the two stacked laminates and heat-sealed to form the bottom. Next, the two sides adjacent to the bottom are heat-sealed to form the body. In this way, a standing pouch of one embodiment can be formed.

[0159] This disclosure relates, for example, to the following [1] to

[10] . [1] A laminate comprising, in the thickness direction, at least a polypropylene resin substrate, a barrier substrate, and a sealant layer, wherein the polypropylene resin substrate is a stretched substrate, the barrier substrate comprises at least an unstretched resin substrate having a polypropylene resin layer and a gas barrier resin layer, and a vapor-deposited film provided on the gas barrier resin layer, and the sealant layer is a resin layer containing polypropylene. [2] The laminate according to [1] above, wherein the gas barrier resin layer contains at least one gas barrier resin selected from polyamide, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyurethane and (meth)acrylic resin. [3] The laminate according to [1] or [2] above, wherein the resin substrate further comprises an adhesive resin layer between a polypropylene resin layer and a gas barrier resin layer. [4] The laminate according to any one of [1] to [3] above, wherein the resin substrate is an unstretched co-extruded resin film. [5] The laminate according to any one of [1] to [4] above, wherein the barrier substrate is arranged such that the vapor-deposited film faces the polypropylene resin substrate side and the polypropylene resin layer faces the sealant layer side. [6] The laminate according to any one of [1] to [5] above, wherein the sealant layer is an unstretched resin film. [7] A laminate according to any one of [1] to [6] above, comprising a first adhesive layer between a polypropylene resin substrate and a barrier substrate, and a second adhesive layer between the barrier substrate and a sealant layer. [8] A laminate according to any one of [1] to [7] above, wherein the polypropylene content in the entire laminate is 80% by mass or more. [9] A laminate according to any of the above [1] to [8], for use as packaging material.

[10] A packaging container comprising the laminate described in any of [1] to [9] above. [Examples]

[0160] The laminates of this disclosure will be described in detail below based on the examples provided.

[0161] [Example 1] The gas barrier resin layer is composed of 6-nylon resin (NY, manufactured by BASF, product name: Ultlamid B36LN, density: 1.13 g / cm³). 3 (Melting point: 220℃, relative viscosity: 3.6) The adhesive resin layer is composed of maleic acid-modified polyolefin (manufactured by Mitsui Chemicals, Inc., product name: Admer QF551T, density: 0.89 g / cm³). 3 (Melting point: 135℃, MFR: 2.5g / 10min), The first polypropylene resin layer is composed of polypropylene (1) (random PP, manufactured by TPC, product name: FL7540L, density: 0.90 g / cm³). 3 (Melting point: 138℃, MFR: 7.0g / 10min), The second polypropylene resin layer is composed of polypropylene (2) (homoPP, manufactured by TPC, product name: FL7013E2, density: 0.90 g / cm³). 3Melting point: 165℃, MFR: 7.0g / 10min)) The third polypropylene resin layer is composed of polypropylene (3) (random PP, manufactured by TPC, product name: FL7642, density: 0.90 g / cm³). 3 (Melting point: 128℃, MFR: 7.0g / 10min) A resin substrate with a total thickness of 25 μm was produced by co-extrusion using the T-die method, and having a structure consisting of a gas barrier resin layer (2 μm) / adhesive resin layer (3 μm) / polypropylene (1) resin layer (2 μm) / polypropylene (2) resin layer (15.5 μm) / polypropylene (3) resin layer (2.5 μm).

[0162] A 60 nm thick aluminum vapor-deposited film was formed on the gas barrier resin layer of the resin substrate prepared as described above by PVD (Physical Vapor Deposition), thereby obtaining a barrier substrate. The optical density (OD value) of the formed vapor-deposited film was measured to be 3.0.

[0163] As a polypropylene resin substrate, a 20 μm thick biaxially oriented polypropylene film (manufactured by Toyobo Co., Ltd., product name: P2171) with one side treated with corona discharge was prepared. An image was formed on the corona discharge treated side of the biaxially oriented polypropylene film using a solvent-based gravure ink (manufactured by DIC Graphics Co., Ltd., Finart) by gravure printing.

[0164] A laminate was obtained by laminating the barrier substrate and the biaxially oriented polypropylene film via a two-component curing polyurethane adhesive (manufactured by Rock Paint Co., Ltd., product name: RU-77T / H-7) so that the aluminum vapor-deposited film-forming surface of the barrier substrate and the image-forming surface of the biaxially oriented polypropylene film faced each other.

[0165] The above polypropylene (1) and polyolefin plastomer (SABIC Corporation, product name: COHERE8102L, density: 0.902 g / cm³) 3Blended polyolefin (1) was prepared by mixing polypropylene (1) (melting point: 98℃, MFR: 1.0g / 10min) in a ratio of 60% by mass and polyolefin plastomer (1) (40% by mass).

[0166] Next, the above-mentioned polypropylene (1) and the above-mentioned blended polyolefin (1) were multilayer extruded using the T-die method to form a polypropylene (1) resin layer (15 μm) / blended polyolefin (1) resin layer (20 μm) to obtain an unstretched polypropylene film (sealant film) with a thickness of 35 μm that constitutes a sealant layer.

[0167] A laminate was obtained by laminating the above-mentioned laminate and the sealant film via a two-component curing polyurethane adhesive (manufactured by Rock Paint Co., Ltd., product name: RU-77T / H-7) so that the polypropylene resin layer of the barrier substrate and the polypropylene (1) resin layer of the sealant film faced each other.

[0168] [Example 2] The resin constituting the gas barrier resin layer is 6-66 copolymer nylon resin (NY, manufactured by BASF, trade name: Ultlamid C33, density: 1.12 g / cm³). 3 A laminate was obtained in the same manner as in Example 1, except that the melting point was changed to 196°C and the relative viscosity to 3.3.

[0169] [Example 3] The resin constituting the gas barrier resin layer is ethylene-vinyl alcohol copolymer (EVOH, manufactured by Kuraray Co., Ltd., product name: EVAL E171B, density: 1.14 g / cm³). 3 A laminate was obtained in the same manner as in Example 1, except that the melting point was changed to 165°C, the MFR to 1.7 g / 10 min, and the ethylene content to 44 mol%).

[0170] [Comparative Example 1] A laminate was obtained in the same manner as in Example 1, except that the resin substrate was changed to a configuration consisting of a polypropylene (1) resin layer (7 μm) / polypropylene (2) resin layer (15.5 μm) / polypropylene (3) resin layer (2.5 μm).

[0171] [Oxygen barrier performance evaluation] The laminates obtained in the examples and comparative examples were cut to A4 size, and the oxygen permeability (cc / m³) was measured using OXTRAN2 / 20 manufactured by MOCON, Inc., USA, in an environment of 23°C and 90% relative humidity. 2 The / day / atm (atm) was measured. The measurement results are shown in Table 1.

[0172] [Evaluation of water vapor barrier properties] The laminates obtained in the examples and comparative examples were cut to A4 size, and the water vapor transmission rate (g / m³) was measured using PERMATRAN3 / 31 manufactured by MOCON, Inc., USA, in an environment of 40°C and 90% relative humidity. 2 The measurement ( / day) was taken. The measurement results are shown in Table 1.

[0173] [Heat sealability test] Sample pieces were prepared by cutting the laminates obtained in the examples and comparative examples into 10 cm x 10 cm sections. These sample pieces were folded in half with the sealant layer facing inward, and then heated at a temperature of 150°C and a pressure of 1 kgf / cm². 2 A 1cm x 10cm area was heat-sealed under a 1-second condition.

[0174] The heat-sealed sample pieces were cut into strips 15 mm wide, and the unheat-sealed ends were held in a tensile testing machine. The peel strength (N / 15 mm) was measured in accordance with JIS Z 0238 under the conditions of a speed of 300 mm / min, a peel angle of 90°, and a load range of 50 N. The measurement results are shown in Table 1.

[0175] [Table 1] [Explanation of Symbols]

[0176] 1: Laminate 10: Polypropylene resin base material 20: Barrier substrate 21: Resin base material 22: Polypropylene resin layer 23: Adhesive resin layer 24: Gas barrier resin layer 25: Deposited film 30: Sealant layer 32: Deposited film 40A, 40B: Adhesive layer

Claims

1. at least, Polypropylene resin substrate, Barrier substrate and sealant layer and A laminate having these elements in this order in the thickness direction, The aforementioned polypropylene resin substrate is a stretched substrate, The barrier substrate comprises at least an unstretched resin substrate having a polypropylene resin layer and a gas barrier resin layer, and a vapor-deposited film provided on the gas barrier resin layer. The polypropylene resin layer comprises a first layer made of random polypropylene, a second layer made of homopolypropylene, and a third layer made of random polypropylene. The sealant layer is a resin layer containing polypropylene. Laminated structure.

2. The laminate according to claim 1, wherein the gas barrier resin layer contains at least one gas barrier resin selected from polyamide, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyurethane, and (meth)acrylic resin.

3. The laminate according to claim 1 or 2, wherein the resin substrate further comprises an adhesive resin layer between the polypropylene resin layer and the gas barrier resin layer.

4. The laminate according to any one of claims 1 to 3, wherein the resin substrate is an unstretched co-extruded resin film.

5. The laminate according to any one of claims 1 to 4, wherein the barrier substrate is arranged such that the vapor-deposited film faces the polypropylene resin substrate side and the polypropylene resin layer faces the sealant layer side.

6. The laminate according to any one of claims 1 to 5, wherein the sealant layer is an unstretched resin film.

7. A first adhesive layer is provided between the polypropylene resin substrate and the barrier substrate. A second adhesive layer is provided between the barrier substrate and the sealant layer. The laminate according to any one of claims 1 to 6.

8. The laminate according to any one of claims 1 to 7, wherein the polypropylene content in the entire laminate is 80% by mass or more.

9. A laminate according to any one of claims 1 to 8, for use as a packaging material.

10. A packaging container comprising a laminate according to any one of claims 1 to 9.

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