Gas barrier laminate, packaging film, packaging container and packaging product

Abstract

To provide a method for producing a gas barrier laminate, which can produce a gas barrier laminate having good appearance and barrier performance.SOLUTION: A method for producing a gas barrier laminate includes the steps of: forming a metal oxide layer on a substrate layer made of a polypropylene resin or a polyester resin by a vacuum film-forming method; applying a composition for forming a gas barrier coating layer onto a metal oxide layer to form a coating film; preheating the coating film with infrared rays; and curing the coating film preheated by infrared rays in an atmosphere of 50 to 120°C to form a gas barrier coating layer, in which a composition for forming the gas barrier coating layer comprises at least one selected from a group consisting of alkyl silicon alkoxides and hydrolysates thereof, and a water-soluble polymer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a gas barrier laminate, a gas barrier laminate, a packaging film, a packaging container, and a packaged product. [Background technology]

[0002] Packaging containers such as packaging bags used for packaging food, medicines, etc., are required to have gas barrier properties that block the intrusion of water vapor, oxygen, and other gases that deteriorate the contents, in order to prevent deterioration and spoilage of the contents and to maintain their functions and properties. For this reason, gas barrier laminates have conventionally been used in these packaging bags.

[0003] A gas barrier laminate generally comprises a base layer, a metal oxide layer and a gas barrier coating layer in this order, and the gas barrier coating layer is formed by applying a gas barrier coating layer-forming composition capable of imparting gas barrier properties onto the metal oxide layer and curing the composition.

[0004] For example, Patent Document 1 below discloses a barrier film having a barrier coating layer, an inorganic oxide vapor deposition layer, and a substrate layer in this order, and the barrier coating layer is formed by applying a gas barrier composition (barrier coating liquid) and then heating and drying at a high temperature of 140°C to 200°C. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-041620 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a barrier film is produced by the method described in Patent Document 1, the base layer is prone to wrinkles, and the barrier coat layer is prone to cracks when subjected to external force. Such a barrier film has room for improvement in appearance and barrier performance.

[0007] The present disclosure has been made in view of the above circumstances, and aims to provide a method for producing a gas barrier laminate capable of producing a gas barrier laminate having good appearance and barrier performance. Another aim of the present disclosure is to provide a gas barrier laminate, a packaging film, a packaging container, and a packaging product. [Means for solving the problem]

[0008] One aspect of the present disclosure provides a method for producing a gas barrier laminate, the method comprising the steps of forming a metal oxide layer on a substrate layer made of a polypropylene resin or a polyester resin by a vacuum film-forming method, applying a composition for forming a gas barrier coating layer on the metal oxide layer to form a coating film, preheating the coating film with infrared rays, and curing the coating film preheated with infrared rays by heating in an atmosphere at 50 to 120°C to form a gas barrier coating layer, wherein the composition for forming a gas barrier coating layer comprises at least one selected from the group consisting of alkyl silicon alkoxides and hydrolysates thereof, and a water-soluble polymer.

[0009] According to the above-mentioned manufacturing method, when forming the gas barrier coating layer, it is possible to cure the gas barrier coating layer uniformly without applying high heat to the entire laminate as in the conventional technology. This prevents wrinkles from occurring in the base layer and also prevents only the surface of the gas barrier coating layer from becoming too hard. Therefore, it is possible to produce a gas barrier laminate with good appearance and barrier performance.

[0010] In one embodiment of the production method of the present disclosure, the composition for forming a gas barrier coating layer may further contain a silane coupling agent, which can further improve the adhesion between the gas barrier coating layer and the metal oxide layer, and can easily suppress intralayer delamination in the gas barrier laminate.

[0011] One aspect of the present disclosure provides a gas barrier laminate comprising, in this order, a substrate layer made of a polypropylene resin or a polyester resin, a metal oxide layer, and a gas barrier coating layer, wherein the surface hardness of the gas barrier coating layer is 0.15 GPa or more and less than 1.10 GPa as measured by a nanoindentation method.

[0012] Such a gas barrier laminate is produced by the above-mentioned manufacturing method, and can be said to be a gas barrier laminate with good appearance and barrier performance, in which the occurrence of wrinkles in the base layer is suppressed and which has a gas barrier coating layer with excellent crack resistance.

[0013] In one embodiment of the gas barrier laminate of the present disclosure, the gas barrier coating layer may have a composite elastic modulus of 11 GPa or less, in which case the gas barrier laminate can be said to have excellent abuse resistance.

[0014] In one embodiment of the gas barrier laminate of the present disclosure, the gas barrier laminate may further include an anchor coat layer between the substrate layer and the metal oxide layer. In this case, the surface smoothness of the anchor coat layer is improved more than that of the substrate layer. Therefore, it is possible to make the thickness of the metal oxide layer uniform, and the gas barrier property of the gas barrier laminate can be further improved.

[0015] In one embodiment of the gas barrier laminate of the present disclosure, the metal oxide layer may contain at least one of aluminum oxide and silicon oxide, thereby making it possible to further improve the gas barrier properties.

[0016] According to one aspect of the present disclosure, there is provided a packaging film comprising the gas barrier laminate and a sealant layer. Since the packaging film comprises the gas barrier laminate, it can be said that the packaging film has good appearance and barrier performance.

[0017] One aspect of the present disclosure provides a packaging container including the packaging film. Since the packaging container includes the packaging film, it can be said that the packaging container has good appearance and barrier performance.

[0018] According to one aspect of the present disclosure, there is provided a packaging product including the packaging container and a content to be filled in the packaging container. Since the packaging product includes the packaging container having a good appearance and barrier performance, the packaging product has excellent visibility of the content and can suppress deterioration of the content due to oxygen intrusion for a long period of time. Effect of the Invention

[0019] According to the present disclosure, it is possible to form a gas barrier coating layer having excellent crack resistance while suppressing the occurrence of wrinkles in the base layer. That is, according to the present disclosure, a method for producing a gas barrier laminate capable of producing a gas barrier laminate having good appearance and barrier performance is provided. In addition, according to the present disclosure, a gas barrier laminate, a packaging film, a packaging container, and a packaged product are provided. [Brief description of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view showing one embodiment of a gas barrier laminate according to the present disclosure. [Diagram 2] FIG. 1 is a cross-sectional view showing one embodiment of a packaging film of the present disclosure. [Diagram 3] FIG. 1 is a side view of one embodiment of a packaging product of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present invention is not limited to the following embodiments.

[0022] <Method of manufacturing gas barrier laminate> The method for producing a gas barrier laminate includes the steps of forming a metal oxide layer on a substrate layer made of polypropylene resin or polyester resin by a vacuum film-forming method, applying a composition for forming a gas barrier coating layer on the metal oxide layer to form a coating film, preheating the coating film with infrared rays, and curing the coating film preheated with infrared rays by heating in an atmosphere at 50 to 120° C. to form a gas barrier coating layer. The above production method may further include a step of forming an anchor coat layer on the substrate layer made of polypropylene resin or polyester resin, as necessary, prior to the step of forming the metal oxide layer.

[0023] An example of a method for producing a gas barrier laminate will now be described.

[0024] First, a base layer made of polypropylene resin or polyester resin is prepared.

[0025] Next, an anchor coat layer is formed on one surface of the base layer. Specifically, the anchor coat layer is formed by applying a composition for forming the anchor coat layer on one surface of the base layer, and then heating and drying the composition. At this time, the heating temperature is, for example, 50 to 120° C., and the heating time is, for example, about 10 seconds to 10 minutes.

[0026] Next, a metal oxide layer is formed on the anchor coat layer. The metal oxide layer can be formed by a vacuum film formation method. Examples of the vacuum film formation method include physical vapor deposition and chemical vapor deposition. Examples of the physical vapor deposition method include vacuum deposition, sputtering deposition, and ion plating. As the physical vapor deposition method, the vacuum deposition method is particularly preferably used. Examples of the vacuum deposition method include resistance heating vacuum deposition, EB (Electron Beam) heating vacuum deposition, and induction heating vacuum deposition. Examples of the chemical vapor deposition method include thermal CVD, plasma CVD, and photo CVD.

[0027] Next, a gas barrier coating layer is formed on the metal oxide layer.

[0028] The gas barrier coating layer can be formed, for example, by applying a composition for forming a gas barrier coating layer onto a metal oxide layer and curing the resulting coating film. As described above, the composition for forming a gas barrier coating layer contains at least one selected from the group consisting of the alkyl silicon alkoxides and their hydrolysates, a water-soluble polymer, and, if necessary, a silane coupling agent. Here, curing the coating film specifically means curing the solid content contained in the coating film. Curing of the solid content means that the alkyl silicon alkoxide or its hydrolysate and the water-soluble polymer, or the alkyl silicon alkoxide or its hydrolysate, the water-soluble polymer, and the silane coupling agent in the solid content react with each other to be integrated.

[0029] The composition for forming a gas barrier coating layer can be applied by a known method, specifically, a wet film forming method such as gravure coating, dip coating, reverse coating, wire bar coating, or die coating.

[0030] The thickness of the coating film is not particularly limited as long as the desired gas barrier coating layer can be obtained, but can be, for example, 700 nm or less. When the thickness of the coating film is 700 nm or less, it is easier to uniformly preheat the coating film with infrared rays than when the thickness of the coating film is more than 700 nm. However, from the viewpoint of improving the gas barrier properties of the formed barrier coating layer, the thickness of the coating film is more preferably 100 nm or more, and particularly preferably 200 nm or more.

[0031] The coating is first preheated with infrared rays. The reason for preheating the coating before heating and curing it with hot air etc. is mainly to prevent surface roughness, to give a uniform amount of heat to the entire coating so that the entire coating dries evenly, and to prevent the heat load on the base film. Although drying (heating) with hot air is an excellent means for drying and hardening a coating film, since it is a drying method that uses convection heat transfer, the coating film is prone to surface roughness. In addition, since drying proceeds from the surface of the coating film, a concentration gradient of the solvent (aqueous medium) is likely to occur in the thickness direction of the coating film. This causes a phenomenon called skinning, in which a concentrated layer is formed on the surface of the coating film and the solvent inside tends to remain without volatilizing. In particular, when a water-soluble polymer such as PVA is used as a solute, skinning is likely to occur due to its high water retention and film-forming properties. When the surface of the coating film shrinks due to skinning, not only does the coating film wrinkle or curl, but heating spots occur on the surface and inside of the coating film. Such heating spots tend to increase the hardness of the surface of the gas barrier coating layer and decrease the hardness inside, so cracks are likely to occur due to external forces such as bending, tension, and heat shock in a retort. The occurrence of cracks leads to deterioration of the barrier properties. In contrast, infrared heating (infrared drying) is a drying method that uses radiant heat transfer, and is less likely to cause surface roughness in the coating film. In addition, infrared rays can heat the coating film uniformly in its thickness direction. Therefore, by performing preheating with infrared rays prior to drying with hot air, the above-mentioned skinning is less likely to occur, and wrinkles and curls in the coating film and base film can be suppressed. In addition, since heating spots are less likely to occur, the hardness of the gas barrier coating layer is more likely to be uniform (only the surface is less likely to become hard), and cracks due to external forces are less likely to occur compared to the above-mentioned skinning state. Furthermore, infrared heating can suppress the heat load on the base film by making the energy addition to the solvent evaporation in the coating film more dominant than the temperature increase of the coating film. The energy provided by infrared heating is used to increase the temperature of the coating film and evaporate the solvent. When the energy addition to the solvent evaporation is dominant, heat energy is taken from the coating film by the latent heat of volatilization of the solvent. When the drying speed by infrared heating is fast and drying is performed efficiently, the heating of the coating film and the latent heat of volatilization are balanced, and the temperature of the coating film does not increase (called constant rate drying). Therefore, not only the coating film but also the underlying base film is kept at a low temperature, so that the thermal load on the base film can be reduced.

[0032] Preheating with infrared rays can be performed using an infrared dryer such as an infrared heater (far-infrared heater). The conditions of the infrared heater are preferably, for example, a central wavelength of 4 to 30 μm (far-infrared). As the infrared rays, any of far-infrared, mid-infrared, and near-infrared rays can be used, but since many solvents have an absorption spectrum in the far-infrared range, far-infrared rays are preferable. In addition, when the solvent is water, dielectric heating using high frequency waves or microwaves can also be used.

[0033] The preheating temperature can be 40° C. or higher, and preferably 50° C. or higher, from the viewpoint of providing a sufficient amount of heat to the entire coating film. Moreover, the preheating temperature can be 70° C. or lower, and preferably 60° C. or lower, from the viewpoint of suppressing the thermal load on the base film. The preheating temperature is the temperature of the surface of the coating film measured with a non-contact surface thermometer (for example, a radiation thermometer FT3700 manufactured by Hioki E.E. Corporation). From the same viewpoint as above, the preheating time can be set to 3 seconds or more, and is preferably 5 seconds or more, and can be set to 15 seconds or less, and is preferably 10 seconds or less.

[0034] The coating film that has undergone the pre-heating step can be said to be in a state in which the amount of solvent is reduced while maintaining a relatively low temperature as described above. In order to harden the solids contained in the coating film (for example, to cause dehydration condensation of silanol groups), it is necessary to raise the temperature of the coating film itself to a certain temperature. Specifically, the coating film can be cured by heating the coating film under a predetermined temperature atmosphere using hot air heating or the like. Hot air heating can be performed using, for example, a jet nozzle type dryer. The heating temperature and heating time are set so that deformation (e.g., thermal shrinkage) of the base layer can be suppressed, and the solid content in the composition for forming a gas barrier coating layer can be cured and liquid such as an aqueous medium can be removed simultaneously. The heating temperature is 50°C or higher, preferably 60°C or higher, and more preferably 80°C or higher, from the viewpoint of curing the solid content in the composition for forming a gas barrier coating layer and removing liquid such as an aqueous medium. In addition, the heating temperature is 120°C or lower, from the viewpoint of suppressing deformation (e.g., thermal shrinkage) of the base layer, but is preferably 110°C or lower. From the same viewpoint as above, the heating time is preferably 3 seconds or more, more preferably 5 seconds or more, and even more preferably 10 seconds or more, and is preferably 10 minutes or less, more preferably 5 minutes or less, and even more preferably 3 minutes or less.

[0035] In this manner, a gas barrier laminate is obtained.

[0036] <Gas barrier laminate> Fig. 1 is a cross-sectional view showing one embodiment of the gas barrier laminate of the present disclosure. In Fig. 1, the gas barrier laminate 10 includes a substrate layer 1 made of a polypropylene resin or a polyester resin, a metal oxide layer 3, and a gas barrier coating layer 4, in this order. The hardness of the gas barrier coating layer 4 is 0.15 GPa or more and less than 1.10 GPa, as measured by a nanoindentation method. The gas barrier laminate 10 may have an anchor coat layer 2 between the substrate layer 1 and the metal oxide layer 3.

[0037] It can be said that this gas barrier laminate 10 is a gas barrier laminate in which the occurrence of wrinkles in the base layer is suppressed and which has good appearance and barrier performance.

[0038] The substrate layer 1, the anchor coat layer 2, the metal oxide layer 3 and the gas barrier coating layer 4 will be described in detail below.

[0039] (base material layer) The base layer 1 is a layer that serves as a support for the gas barrier coating layer 4, and is made of a polypropylene resin. The base layer 1 is made of a polypropylene resin, which improves the recyclability of the packaging film obtained by laminating the base layer 1 with, for example, non-oriented polypropylene (CPP). The base layer 1 may be substantially made of a polypropylene resin, and the polypropylene resin may be a homopolypropylene or a propylene copolymer. The content of the polypropylene resin may be 99.5 mass% or more based on the total amount of the base layer 1. The base layer 1 may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, and lubricants as trace components. The base layer 1 may be subjected to a surface treatment such as a plasma treatment in order to improve adhesion to the layer to be laminated.

[0040] The substrate layer 1 may be made of a polyester (based) resin. The substrate layer 1 made of a polyester resin improves the heat resistance of the gas barrier laminate. The substrate layer 1 may be made substantially of a polyester resin, and examples of the polyester resin include polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene naphthalate resin (PEN), and polybutylene naphthalate resin (PBN). Examples of PET include virgin PET newly synthesized from raw materials such as petroleum, and recycled PET, which is recycled PET. PET products to be recycled include used PET bottles. Examples of recycled PET include PET recycled by mechanical recycling and PET recycled by chemical recycling. A part of the terephthalic acid in PET may be modified to phthalic acid. The content of the polyester resin may be 99.5% by mass or more based on the total amount of the substrate layer 1. The substrate layer 1 may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, and lubricants as trace components. The substrate layer 1 may be subjected to a surface treatment such as a plasma treatment in order to improve adhesion to the layer to be laminated thereon.

[0041] The base layer 1 may be a stretched film or a non-stretched film, but is preferably a stretched film from the viewpoint of oxygen barrier properties. Examples of the stretched film include uniaxially stretched films and biaxially stretched films, and the biaxially stretched film is preferred because it improves heat resistance.

[0042] The thickness of the base layer 1 is not particularly limited, but may be, for example, 0.1 mm or less. In particular, the thickness of the base layer 1 is preferably 40 μm or less, more preferably 35 μm or less, and particularly preferably 30 μm or less. When the thickness of the base layer 1 is 0.1 mm or less, the flexibility of the gas barrier laminate 10 is further improved compared to when the thickness of the base layer 1 exceeds 0.1 mm, and the oxygen gas barrier property of the gas barrier laminate 10 after abuse can be further improved. However, from the viewpoint of improving the strength, the thickness of the base layer 1 is preferably 10 μm or more, and more preferably 12 μm or more.

[0043] (Anchor coat layer) The anchor coat layer 2 is a layer for further improving the adhesion between the substrate layer 1 and the metal oxide layer 3, and is provided between the substrate layer 1 and the metal oxide layer 3.

[0044] The material constituting the anchor coat layer 2 is not particularly limited as long as it can improve the adhesion between the base layer 1 and the metal oxide layer 3, and such materials include a reaction product of an organosilane or an organometallic compound, a polyol compound, and an isocyanate compound. That is, the anchor coat layer 2 can also be said to be a urethane-based adhesive layer. The organosilane is, for example, a trifunctional organosilane, or a hydrolyzate of a trifunctional organosilane. The organometallic compound is, for example, a metal alkoxide or a hydrolyzate of a metal alkoxide. The metal element contained in the organometallic compound is, for example, Al, Ti, Zr, etc. The organosilane hydrolyzate and the metal alkoxide hydrolyzate each only need to have at least one hydroxyl group. From the viewpoint of transparency, the polyol compound is preferably an acrylic polyol. The isocyanate compound mainly functions as a crosslinking agent or a curing agent. The polyol compound and the isocyanate compound may be a monomer or a polymer.

[0045] The thickness of the anchor coat layer 2 is not particularly limited as long as it can improve the adhesion between the base layer 1 and the metal oxide layer 3, but is preferably 30 nm or more. In this case, the smoothness of the surface of the anchor coat layer 2 can be improved more than that of the surface of the base layer 1, the thickness of the metal oxide layer 3 can be made more uniform, and the oxygen barrier property can be improved. Therefore, the oxygen barrier property of the gas barrier laminate 10 can be further improved. The thickness of the anchor coat layer 2 is more preferably 40 nm or more, and more preferably 50 nm or more. By increasing the thickness of the anchor coat layer 2, the decrease in the water vapor barrier property when an external force such as stretching is applied can be further suppressed. The thickness of the anchor coat layer 2 is preferably 300 nm or less. In this case, the flexibility of the gas barrier laminate 10 is further improved, and the oxygen gas barrier property of the gas barrier laminate 10 after abuse can be further improved, compared to when the thickness of the anchor coat layer 2 exceeds 300 nm. The thickness of the anchor coat layer 2 is more preferably 200 nm or less.

[0046] (Metal oxide layer) The metal oxide layer 3 is a layer containing a metal oxide. By including the metal oxide layer 3, the gas barrier laminate 10 can further improve the gas barrier properties.

[0047] The metal constituting the metal oxide includes at least one atom selected from the group consisting of Si, Al, Mg, Sn, Ti, and In. From the viewpoint of water vapor barrier properties, the metal oxide is preferably SiO x or AlO x (silicon oxide or aluminum oxide) is preferred. Among them, the metal oxide is SiO x In this case, the gas barrier laminate 10 can have better water vapor barrier properties. The metal oxide layer 3 may be composed of a single layer or multiple layers.

[0048] The thickness of the metal oxide layer 3 is not particularly limited, but is preferably 5 nm or more. In this case, the oxygen barrier property of the gas barrier laminate 10 is further improved compared to when the thickness of the metal oxide layer 3 is less than 5 nm. The thickness of the metal oxide layer 3 is more preferably 8 nm or more, and particularly preferably 10 nm or more.

[0049] The thickness of the metal oxide layer 3 is preferably 80 nm or less. In this case, the flexibility of the gas barrier laminate 10 is improved and the oxygen barrier property of the gas barrier laminate 10 after abuse can be improved more than when the thickness of the metal oxide layer 3 exceeds 80 nm. The oxygen barrier property of the gas barrier laminate 10 after retort treatment can also be improved more. The thickness of the metal oxide layer 3 is more preferably 70 nm or less, and particularly preferably 60 nm or less.

[0050] (Gas barrier coating layer) The gas barrier coating layer 4 is formed of a cured product of a composition for forming a gas barrier coating layer. That is, the gas barrier coating layer 4 can be said to be a heat-cured product of a composition containing at least one selected from the group consisting of alkyl silicon alkoxides and hydrolysates thereof, and a water-soluble polymer.

[0051] The hardness of the gas barrier coating layer 4 is 0.15 GPa or more and less than 1.10 GPa as measured by the nanoindentation method. A hardness of 0.15 GPa or more indicates that the solid content in the composition for forming a gas barrier coating layer has been sufficiently cured and that liquids such as the aqueous medium have been sufficiently removed. Furthermore, a hardness of 0.15 GPa or more ensures the required barrier properties while suppressing offset caused by the layer being too soft, making it easier to form a uniform layer. Furthermore, the heat shock resistance is improved, making it less likely to deteriorate due to retort treatment or the like. On the other hand, a hardness of less than 1.10 GPa indicates that excessive heat was not applied to the base layer when the solid content in the composition for forming a gas barrier coating layer was cured and the liquid such as the aqueous medium was removed by heating, which means that deformation of the base layer (e.g., thermal shrinkage) was suppressed. In addition, a hardness of less than 1.10 GPa prevents the layer from becoming too hard, improving the resistance to abuse.

[0052] The hardness of the gas barrier coating layer 4 is preferably 0.20 GPa or more, more preferably 0.50 GPa or more, and preferably 1.05 GPa or less, more preferably 1.0 GPa or less, and even more preferably 0.7 GPa or less.

[0053] The composite elastic modulus of the gas barrier coating layer 4 is preferably 11 GPa or less. In this case, it can be said that the gas barrier laminate has excellent resistance to abuse. The composite elastic modulus of the gas barrier coating layer 4 is more preferably 10 GPa or less, further preferably 9 GPa or less, and particularly preferably 7 GPa. There is no particular lower limit for the composite elastic modulus, but it can be 2 GPa or 6 GPa from the viewpoint of barrier properties.

[0054] The hardness and composite elastic modulus of the gas barrier coating layer 4 are measured by a nanoindentation method, which is a measurement method for performing a quasi-static indentation test on a target measurement object to obtain the mechanical properties of the sample. The measurement sample (cross-sectional sample) is prepared as follows. That is, after performing corona treatment on both sides of the gas barrier laminate, it is embedded in visible light curable resin D-800. Then, using an ultramicrotome Leica EM UC7 and a diamond knife Microstar LH, the gas barrier laminate is cut perpendicular to the lamination direction. The resulting cross section is finished under the conditions of a cutting thickness Feed of 100 nm and a cutting speed Speed ​​of 1 mm / s to prepare the measurement sample. For the measurement, a Hysitron TI-Premier (product name) manufactured by Bruker Japan Co., Ltd. is used as the measuring device, and a Berkovich type diamond indenter manufactured by Bruker Japan Co., Ltd. is used as the indenter. The measurement conditions are as follows. Temperature: normal temperature (25℃). Mode: Load control mode. Indentation and unloading: The load is indented up to 15 μN at a pressing speed of 1.5 μN / sec, the maximum load is maintained for 5 seconds, and then the load is removed at a speed of 1.5 μN / sec. Measurement locations: A shape measurement function of the measuring device scans the sample surface with an indenter to obtain a shape image of the cross section of the gas barrier coating layer, and 20 points are specified on the cross section of the gas barrier coating layer at intervals of 1 μm or more from the shape image. When calculating the hardness and composite elastic modulus, the relationship between the contact depth and the contact projection area between the indenter and the sample is calibrated in advance using fused quartz as a standard sample. After that, the unloading curve in the 60-95% region of the maximum load at the time of unloading is analyzed by the Oliver-Pharr method, and the hardness and composite elastic modulus are calculated.

[0055] The composition for forming a gas barrier coating layer contains at least one selected from the group consisting of alkyl silicon alkoxides and hydrolysates thereof, and a water-soluble polymer. Alkyl silicon alkoxides are represented by the following general formula (1): Si(OR 1 ) 4 It is expressed as: Si(OR 1 ) 4 ...(1) In general formula (1), R 1 represents an alkyl group. Examples of the alkyl group include a methyl group and an ethyl group. Among them, an ethyl group is preferable. In this case, the alkyl silicon alkoxide becomes tetraethoxysilane, which becomes relatively stable in an aqueous solvent after hydrolysis.

[0056] The content of alkyl silicon alkoxide (and at least one selected from the group consisting of hydrolyzates thereof) in the solid content is not particularly limited.2 When converted to alkyl silicon alkoxide, it is preferably 8% by mass or more, more preferably 15% by mass or more, particularly preferably 20% by mass or more, and even more preferably 30% by mass or more, 40% by mass or more, or 45% by mass or more. When the alkyl silicon alkoxide content in the solid content is 8% by mass or more, the oxygen gas barrier property and adhesion of the gas barrier laminate after heat sterilization treatment can be further improved compared to when the alkyl silicon alkoxide content in the solid content is less than 8% by mass. The content of alkyl silicon alkoxide in the solid content is preferably 80 mass% or less, more preferably 78 mass% or less, and particularly preferably 75 mass% or less. When the content of alkyl silicon alkoxide in the solid content is 80 mass% or less, the oxygen gas barrier property of the gas barrier laminate after abuse can be further improved compared to when the content of alkyl silicon alkoxide in the solid content exceeds 80 mass%.

[0057] Examples of water-soluble polymers include polyvinyl alcohol resins, modified products thereof, and polyacrylic acid. These can be used alone or in combination of two or more. Among them, polyvinyl alcohol resins or modified products thereof are preferable as water-soluble polymers. In this case, the composition can impart better gas barrier properties to the gas barrier laminate 10 by curing. In addition, even when cured, the composition can impart better flexibility to the gas barrier laminate 10, and can further improve the oxygen barrier properties after abuse.

[0058] When the water-soluble polymer is composed of a polyvinyl alcohol resin or a modified product thereof, the degree of saponification of the water-soluble polymer is not particularly limited, but from the viewpoint of improving the gas barrier properties of the gas barrier laminate 10, it is preferably 95% or more, and may be 100%.

[0059] The degree of polymerization of the water-soluble polymer is not particularly limited, but is preferably 300 or more from the viewpoint of improving the gas barrier property of the gas barrier laminate 10. The degree of polymerization of the water-soluble polymer is preferably 450 to 2400.

[0060] The content of the water-soluble polymer in the solid content is preferably 20% by mass or more, more preferably 22% by mass or more, and particularly preferably 25% by mass or more. When the content of the water-soluble polymer in the solid content is 20% by mass or more, the oxygen gas barrier property of the gas barrier laminate after abuse can be further improved compared to when the content of the water-soluble polymer in the solid content is less than 20% by mass. The content of the water-soluble polymer in the solid content is preferably 92% by mass or less, more preferably 85% by mass or less, particularly preferably 80% by mass or less, and even more preferably 70% by mass or less, 60% by mass or less, or 55% by mass or less. When the content of the water-soluble polymer in the solid content is 92% by mass or less, the interlayer adhesion in the gas barrier laminate 10 after retort treatment can be further improved compared to when the content of the water-soluble polymer in the solid content exceeds 92% by mass.

[0061] The composition for forming a gas barrier coating layer may further contain a silane coupling agent as a curing agent.

[0062] The silane coupling agent is not particularly limited, but is preferably at least one selected from the group consisting of silicon compounds represented by the following general formula (2) and hydrolysates thereof. (R 2 Si(OR 3 ) 3 ) n ...(2) In the above general formula (2), R 2 represents a monovalent organic functional group, and R 3 is an alkyl group or -C 2 H 4 OCH 3 Represents. In this case, it is possible to improve the adhesion between the gas barrier coating layer 4 and the metal oxide layer 3, and delamination between layers in the gas barrier laminate 10 can be suppressed. In addition, R 2 and R 3 may be the same or different. 3 They may be the same or different from each other. R 2 Examples of the monovalent organic functional group represented by the formula (I) include a monovalent organic functional group containing a vinyl group, an epoxy group, a mercapto group, an amino group, or an isocyanate group. Among them, the monovalent organic functional group is preferably an isocyanate group. In this case, the composition can have better hot water resistance by curing, and it is possible to impart greater laminate strength to the gas barrier laminate 10 even after retort treatment. R 3 Examples of the alkyl group represented by the formula (1) include a methyl group and an ethyl group. Among them, a methyl group is preferable. In this case, hydrolysis is carried out quickly. n represents an integer of 1 or more. When n is 1, the silane coupling agent represents a monomer, whereas when n is 2 or more, the silane coupling agent represents a polymer. n is preferably 3. In this case, the hot water resistance of the gas barrier coating layer 4 can be further improved, and it is possible to impart greater laminate strength to the gas barrier laminate 10 even after retort treatment.

[0063] Examples of the silane coupling agent include silane coupling agents having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane; silane coupling agents having an epoxy group such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylethyldiethoxysilane; silane coupling agents having a mercapto group such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane; silane coupling agents having an amino group such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane; and silane coupling agents having an isocyanate group such as 3-isocyanatepropyltriethoxysilane and 1,3,5-tris(3-methoxysilylpropyl)isocyanurate. These silane coupling agents may be used alone or in combination of two or more.

[0064] The content of the silane coupling agent in the solid content is not particularly limited, but is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 5% by mass or more. In this case, the gas barrier laminate 10 can be given a greater laminate strength by curing even after retort treatment, compared to when the content of the silane coupling agent in the solid content is less than 1% by mass. The content of the silane coupling agent in the solid content is preferably 20% by mass or less, more preferably 18% by mass or less, particularly preferably 15% by mass or less, and even more preferably 10% by mass or less. In this case, the silane coupling agent is less likely to bleed out and contaminate the surface, compared with the case where the content of the silane coupling agent in the solid content exceeds 20% by mass. The content of the silane coupling agent in the solid content is, for example, when the silane coupling agent is represented by the above general formula (2), the mass of the silane coupling agent is represented by R 2 Si(OH) 3 It is calculated by converting it into mass.

[0065] (Other components in solids) The solid content may further contain known additives such as dispersants, stabilizers, viscosity adjusters, colorants, etc., as necessary, to the extent that the gas barrier properties of the gas barrier coating layer 4 are not impaired.

[0066] (Total content of ingredients in solids) The total content of the alkyl silicon alkoxide or its hydrolysate, the water-soluble polymer, and the silane coupling agent in the solid matter is not particularly limited, but is usually 95% by mass or more, preferably 97% by mass or more, and may be 100% by mass.

[0067] (liquid) As the liquid for dissolving or dispersing the solid content, an aqueous medium is usually used. Examples of the aqueous medium include water, a hydrophilic organic solvent, or a mixture thereof. Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; cellosolves; carbitols; and nitriles such as acetonitrile. These can be used alone or in combination of two or more.

[0068] The aqueous medium is preferably an aqueous medium consisting of water alone or an aqueous medium containing water as a main component. When the aqueous medium contains water as a main component, the content of water in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more.

[0069] The thickness of the gas barrier coating layer 4 is not particularly limited, but is preferably 50 nm or more. In this case, the oxygen barrier property of the gas barrier laminate 10 is further improved, compared to when the thickness of the gas barrier coating layer 4 is less than 50 nm.

[0070] From the viewpoint of improving the gas barrier property, the thickness of the gas barrier coating layer 4 is more preferably 100 nm or more, and particularly preferably 200 nm or more. On the other hand, the thickness of the gas barrier coating layer 4 is preferably 700 nm or less. Compared with a thickness of the gas barrier coating layer 4 exceeding 700 nm, the flexibility of the gas barrier laminate 10 is improved, and the oxygen barrier property of the gas barrier laminate 10 after abuse can be improved. In addition, the oxygen barrier property of the gas barrier laminate 10 after retort treatment can be improved.

[0071] From the viewpoint of further improving the flexibility of the gas barrier laminate 10, the thickness of the gas barrier coating layer 4 is more preferably 500 nm or less, and particularly preferably 400 nm or less.

[0072] <Packaging film> Next, an embodiment of the packaging film of the present disclosure will be described with reference to Fig. 2. In Fig. 2, the same components as those in Fig. 1 are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0073] Fig. 2 is a cross-sectional view showing one embodiment of the packaging film of the present disclosure. As shown in Fig. 2, the packaging film 20 includes a gas barrier laminate 10 and a sealant layer 21 laminated on the gas barrier laminate 10, and the sealant layer 21 is disposed on the gas barrier coating layer 4 side of the base layer 1 of the gas barrier laminate 10. As shown in Fig. 2, in the gas barrier laminate 10, the gas barrier coating layer 4 and the sealant layer 21 may be bonded by an adhesive layer 22.

[0074] Since the packaging film 20 includes the gas barrier laminate 10, it can be said that the film has good appearance and barrier performance.

[0075] For example, polyester-isocyanate resin, urethane resin, polyether resin, etc. can be used as the material of the adhesive layer 22. When the packaging film 20 is used for retort applications, a two-component curing type urethane adhesive that is resistant to retort treatment can be preferably used.

[0076] (Sealant layer) Examples of the material of the sealant layer 21 include thermoplastic resins such as polyolefin resins and polyester resins, but polyolefin resins are generally used. Specifically, examples of the polyolefin resin that can be used include ethylene-based resins such as low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), linear low-density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-(meth)acrylic acid copolymer, and polypropylene-based resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer, and mixtures thereof. The material of the sealant layer 21 can be appropriately selected from the above-mentioned thermoplastic resins depending on the intended use and temperature conditions such as boiling and retorting.

[0077] The thermoplastic resin constituting the sealant layer 21 may be stretched or unstretched, but from the viewpoint of lowering the melting point and facilitating heat sealing, it is preferable that it is unstretched (e.g., CPP).

[0078] The thickness of the sealant layer 21 is appropriately determined depending on the mass of the contents, the shape of the packaging bag, etc., and is not particularly limited, but from the viewpoint of the flexibility and adhesiveness of the packaging film 20, it is preferably 30 to 150 μm.

[0079] <Packaging products> Next, an embodiment of the packaging product of the present disclosure will be described with reference to Fig. 3. Fig. 3 is a side view showing one embodiment of the packaging product of the present disclosure. In Fig. 3, the same components as those in Fig. 1 or 2 are denoted by the same reference numerals, and duplicated explanations will be omitted. As shown in Fig. 3, a packaged product 40 includes a packaging container 30 and a content C filled in the packaging container 30. The packaging container 30 shown in Fig. 3 is obtained by using a pair of packaging films 20 and heat-sealing the peripheral portions of the packaging films 20 with the sealant layers 21 facing each other. Note that the adhesive layer 22 of the packaging films 20 is omitted in Fig. 3.

[0080] This packaging product 40 includes a packaging container 30, which has a good appearance and barrier performance, allowing for excellent visibility of the contents and preventing deterioration of the quality of the contents C due to oxygen contamination over a long period of time.

[0081] The packaging container 30 can also be obtained by folding one packaging film 20 and heat-sealing the periphery of the packaging film 20 with the sealant layers 21 facing each other.

[0082] Examples of the packaging container 30 include a packaging bag, a laminated tube container, and a liquid paper container.

[0083] The content C is not particularly limited, and examples of the content C include food, liquid, medicine, and electronic parts.

[0084] The present disclosure is not limited to the above embodiment. For example, in the above embodiment, the sealant layer 21 is disposed on the gas barrier coating layer 4 side of the base layer 1 of the gas barrier laminate 10 in the packaging film 20, but the sealant layer 21 may be disposed on the opposite side of the base layer 1 to the gas barrier coating layer 4.

[0085] <Outline of this embodiment> [1] forming a metal oxide layer on a substrate layer made of a polypropylene resin or a polyester resin by a vacuum deposition method; A step of applying a composition for forming a gas barrier coating layer onto the metal oxide layer to form a coating film; preheating the coating film by infrared rays; and curing the coating film preheated by the infrared rays in an atmosphere of 50 to 120°C to form a gas barrier coating layer. The method for producing a gas barrier laminate, wherein the composition for forming a gas barrier coating layer comprises at least one selected from the group consisting of alkyl silicon alkoxides and hydrolysates thereof, and a water-soluble polymer. [2] The method according to [1], wherein the composition for forming a gas barrier coating layer further contains a silane coupling agent. [3] A substrate layer made of a polypropylene resin or a polyester resin, a metal oxide layer, and a gas barrier coating layer, in this order; The gas barrier laminate, wherein the hardness of the gas barrier coating layer is 0.15 GPa or more and less than 1.10 GPa as measured by a nanoindentation method. [4] The gas barrier laminate according to [3], wherein the gas barrier coating layer has a composite elastic modulus of 11 GPa or less. [5] The gas barrier laminate according to [3] or [4], further comprising an anchor coat layer between the base layer and the metal oxide layer. [6] The gas barrier laminate according to any one of [3] to [5], wherein the metal oxide layer contains at least one of aluminum oxide and silicon oxide. [7] A packaging film comprising the gas barrier laminate according to any one of [3] to [6] and a sealant layer. [8] A packaging container comprising the packaging film described in [7]. [9] A packaging product comprising the packaging container described in [8] and contents filled into the packaging container. EXAMPLES

[0086] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples.

[0087] <Preparation of coating solution> Coating solutions 1 and 2 as gas barrier coating layer-forming compositions used in each example were prepared as follows.

[0088] (Coating Liquid 1) The following solutions A to C were mixed to obtain coating solution 1. Coating solution 1 has a solid content of 100, which is TEOS (SiO 2 Conversion value) and PVA and isocyanurate silane (R 2 Si(OH) 3 The mass ratio of the cellulose acetate to the cellulose acetate equivalent (converted value) was adjusted to be 68 / 27 / 5. Liquid A: 17.9 g of tetraethoxysilane (trade name: KBE04, solid content: 100%, manufactured by Shin-Etsu Chemical Co., Ltd., also known as "TEOS") as an alkyl silicon alkoxide, 10 g of methanol (Kanto Chemical), and 72.1 g of 0.1 N hydrochloric acid (manufactured by Kanto Chemical Co., Ltd.) were mixed and hydrolyzed into a solution (5% by mass of TEOS (SiO 2 Conversion) Hydrolysis solution). Liquid B: A 5% by mass aqueous solution of polyvinyl alcohol (product name: Kuraray Poval 60-98, manufactured by Kuraray Co., Ltd., also known as "PVA"). C liquid: 1,3,5-tris(3-methoxysilylpropyl)isocyanurate (product name: X-12-965P, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent (SC agent) was dissolved in a water / IPA mixed solution of 1 / 1 by mass, with a solid content of 5% (mass ratio, R 2 Si(OH) 3 A solution that has been diluted and adjusted to obtain a concentration of 1:1 (conversion).

[0089] (Coating Liquid 2) The above-mentioned solutions A to C were mixed to obtain coating solution 2. Coating solution 2 has a solid content of 100, which is TEOS (SiO 2 Conversion value) and PVA and isocyanurate silane (R 2 Si(OH) 3 The mass ratio of the cellulose acetate solution (converted value) was adjusted to 47.6 / 47.6 / 4.8.

[0090] <Preparation of anchor coat layer forming composition> The composition for forming the anchor coat layer was prepared as follows. Acrylic polyol and tolylene diisocyanate were mixed so that the number of NCO groups of tolylene diisocyanate was equal to the number of OH groups of the acrylic polyol, and diluted with ethyl acetate so that the solid content (total amount of acrylic polyol and tolylene diisocyanate) was 5 mass%. β-(3,4 epoxycyclohexyl)trimethoxysilane was further added to the diluted mixed solution so that it was 5 mass parts per 100 mass parts of the total amount of acrylic polyol and tolylene diisocyanate, and these were mixed to prepare a composition for forming an anchor coat layer (anchor coat agent).

[0091] <Preparation of gas barrier laminate: Experiment A (PP)> (Example A-1) A gas barrier laminate was produced by a roll-to-roll method as follows: First, a polypropylene resin film (trade name "U-1", biaxially oriented film: OPP, manufactured by Mitsui Chemicals Tocello Inc.) having a thickness of 20 μm as a base layer was loaded onto an unwinding device, a conveying device, and a winding device.

[0092] Next, the composition for forming the anchor coat layer prepared as described above was applied to one side of the substrate layer during transportation by gravure coating to form a coating film.The coating film was then heated at 120°C for 10 seconds and dried to form an anchor coat layer (AC layer) with a thickness of 50 nm, and a laminate was obtained.The laminate thus obtained was wound up by a winding device to obtain a roll-shaped laminate.

[0093] Next, the rolled laminate was loaded onto an unwinding device, a conveying device, and a winding device. The laminate was then unwound from the rolled laminate, and SiO was applied to the anchor coat layer of the laminate being conveyed to a thickness of 20 nm. x A film (metal oxide layer) was formed. x The film was formed by evaporating silicon dioxide by electron beam heating using an electron beam heating type vacuum deposition apparatus.

[0094] This SiO x Coating solution 1 was applied onto the film to form a coating film. The coating film thus formed was preheated with far-infrared rays using a far-infrared heater under the conditions of preheating temperature: 50°C, time: 5 seconds. The conditions of the far-infrared heater were central wavelength: 6 μm, ceramic temperature: 203°C, and emissivity: 0.93.

[0095] The coating film preheated by infrared rays was further heated and dried using a shot nozzle type dryer under the conditions shown in Table 1 (at 60°C for 60 seconds) to form a gas barrier coating layer having a thickness of 300 nm. At this time, the heating was performed so as to remove the liquid in Coating Liquid 1 while the TEOS, PVA, and isocyanurate silane constituting the solid content in Coating Liquid 1 were cured to form a cured body.

[0096] In this manner, a gas barrier laminate was obtained in which the base layer, the anchor coat layer, the metal oxide layer, and the gas barrier coating layer were laminated in this order.

[0097] (Examples A-2, A-4 and A-5) A gas barrier laminate was obtained in the same manner as in Example A-1, except that the thickness of the barrier coating layer and the drying conditions were as shown in Table 1.

[0098] (Example A-3) Except for the fact that the anchor coat layer was not formed and the surface treatment was performed on one side of the base layer, the layers were laminated in the same manner as in Example A-1 to obtain a gas barrier laminate in which the base layer, the metal oxide layer, and the gas barrier coating layer were laminated in this order. The surface treatment was performed by performing a plasma treatment by glow discharge (output 350 W) on the surface of the base layer in a vacuum device. The treatment atmosphere was oxygen gas (10 Pa).

[0099] (Example A-6) On the anchor coat layer, AlO xA gas barrier laminate was obtained in the same manner as in Example A-1, except that an AlO x The film was formed by evaporating an aluminum ingot with electron beam heating using a vacuum deposition device under a pressure of 1.2 × 10 -2 This was carried out by introducing oxygen to a pressure of 1 Pa.

[0100] (Example A-7) A gas barrier laminate was obtained in the same manner as in Example A-6, except that the thickness of the barrier coating layer and the drying conditions were as shown in Table 1.

[0101] (Examples A-8 and A-9) A gas barrier laminate was obtained in the same manner as in Example A-1, except that Coating Liquid 2 was used instead of Coating Liquid 1, and the thickness of the barrier coating layer and the drying conditions were as shown in Table 1.

[0102] (Examples A-10 and A-11) A gas barrier laminate was obtained in the same manner as in Example A-6, except that Coating Liquid 2 was used instead of Coating Liquid 1, and the thickness of the barrier coating layer and the drying conditions were as shown in Table 1.

[0103] (Comparative Examples A-1 and A-3) A gas barrier laminate was obtained in the same manner as in Example A-1, except that the barrier coating layer was not subjected to far-infrared heating, and the thickness and drying conditions of the barrier coating layer were as shown in Table 1.

[0104] (Comparative Examples A-2 and A-4) A gas barrier laminate was obtained in the same manner as in Example A-1, except that Coating Liquid 2 was used instead of Coating Liquid 1, that the barrier coating layer was not subjected to far-infrared heating, and that the thickness and drying conditions of the barrier coating layer were as shown in Table 1.

[0105] <Preparation of gas barrier laminate: Experiment B (PET)> (Example B-1) A gas barrier laminate was produced by a roll-to-roll method as follows: First, a polyethylene terephthalate (PET) film (product name "P60": manufactured by Toray Industries, Inc.) having a thickness of 12 μm as a base layer was loaded onto an unwinding device, a conveying device, and a winding device.

[0106] Next, a surface treatment was applied to one side of the base layer during transportation. The surface treatment was performed by applying plasma treatment to the surface of the base layer by glow discharge (output 350 W) in a vacuum device. The treatment atmosphere was oxygen gas (10 Pa). This was wound up by a winding device to obtain a rolled PET film that had been subjected to a surface treatment.

[0107] Next, the rolled PET film was loaded onto an unwinding device, a conveying device, and a winding device. Then, the PET film was unwound from the rolled PET film, and SiO was applied to the surface-treated side of the PET film being conveyed to a thickness of 20 nm. x A film (metal oxide layer) was formed. x The film was formed by evaporating silicon dioxide by electron beam heating using an electron beam heating type vacuum deposition apparatus.

[0108] This SiO x Coating solution 1 was applied onto the film to form a coating film. The coating film thus formed was preheated with far-infrared rays using a far-infrared heater under the conditions of preheating temperature: 50°C, time: 5 seconds. The conditions of the far-infrared heater were central wavelength: 6 μm, ceramic temperature: 203°C, and emissivity: 0.93.

[0109] The coating film preheated by infrared rays was further heated and dried using a shot nozzle type dryer under the conditions shown in Table 2 (at an atmosphere of 80°C for 60 seconds) to form a gas barrier coating layer having a thickness of 300 nm. At this time, the heating was performed so as to remove the liquid in Coating Liquid 1 while the TEOS, PVA, and isocyanurate silane constituting the solid content in Coating Liquid 1 were cured to form a cured body.

[0110] In this manner, a gas barrier laminate was obtained in which the substrate layer, the metal oxide layer, and the gas barrier coating layer were laminated in this order.

[0111] (Example B-2) An anchor coat layer was formed without surface treatment. Specifically, the composition for forming an anchor coat layer prepared as described above was applied to one side of the substrate layer being transported by gravure coating to form a coating film. The coating film was then heated at 120°C for 10 seconds and dried to form an anchor coat layer (AC layer) having a thickness of 50 nm, thereby obtaining a laminate. The thus obtained laminate was wound up by a winding device to obtain a roll-shaped laminate. Thereafter, the obtained roll-shaped laminate was used to laminate each layer in the same manner as in Example B-1, thereby obtaining a gas barrier laminate in which the substrate layer, the anchor coat layer, the metal oxide layer, and the gas barrier coating layer were laminated in this order.

[0112] (Example B-3) On the anchor coat layer, AlO x A gas barrier laminate was obtained in the same manner as in Example B-2, except that an AlO x The film was formed by evaporating an aluminum ingot with electron beam heating using a vacuum deposition device under a pressure of 1.2 × 10 -2 This was carried out by introducing oxygen to a pressure of 1 Pa.

[0113] (Example B-4) A gas barrier laminate was obtained in the same manner as in Example B-3, except that the thickness of the barrier coating layer and the drying conditions were as shown in Table 2.

[0114] (Example B-5) A gas barrier laminate was obtained in the same manner as in Example B-3, except that a 15 μm thick polybutylene terephthalate (PBT) film (product name "Boblet ST": manufactured by Kohjin Film & Chemicals Co., Ltd.) was used as the base layer instead of the PET film, and the drying conditions for the barrier coating layer were as shown in Table 2.

[0115] (Example B-6) A gas barrier laminate was obtained in the same manner as in Example B-3, except that a 12 μm-thick polyethylene naphthalate (PEN) film (product name "Teonex Q51": manufactured by Toyobo Co., Ltd.) was used as the base layer instead of the PET film, and the drying conditions for the barrier coating layer were as shown in Table 2.

[0116] (Comparative Examples B-1 and B-3) A gas barrier laminate was obtained in the same manner as in Example B-3, except that the barrier coating layer was not subjected to far-infrared heating, and the thickness and drying conditions of the barrier coating layer were as shown in Table 2.

[0117] (Comparative example B-2) AlO x A gas barrier laminate was obtained in the same manner as in Example B-1, except that a film (metal oxide layer) was formed, that the barrier coating layer was not subjected to far-infrared heating, and that the thickness and drying conditions of the barrier coating layer were as shown in Table 2.

[0118] <Measurement of hardness and composite elastic modulus of gas barrier coating layer> The hardness and composite elastic modulus of the gas barrier coating layer of the gas barrier laminate obtained in each example were measured by the nanoindentation method as follows. The measurement sample (cross-sectional sample) was prepared as follows. That is, after corona treatment was performed on both sides of the gas barrier laminate, it was embedded in visible light curable resin D-800. Then, the gas barrier laminate was cut perpendicular to the lamination direction with a diamond knife Microstar LH using an ultramicrotome Leica EM UC7. The resulting cross section was finished under the conditions of a cutting thickness Feed of 100 nm and a cutting speed Speed ​​of 1 mm / s to prepare a measurement sample. For the measurement, a Hysitron TI-Premier (product name) manufactured by Bruker Japan Co., Ltd. was used as the measuring device, and a Berkovich type diamond indenter manufactured by Bruker Japan Co., Ltd. was used as the indenter. The measurement conditions were as follows. Temperature: normal temperature (25℃). Mode: Load control mode. Pressing and unloading: Pressing was performed up to a load of 15 μN at a pressing speed of 1.5 μN / s, the maximum load was maintained for 5 seconds, and then the load was removed at a speed of 1.5 μN / s. Measurement locations: A shape measurement function of the measuring device scans the sample surface with an indenter to obtain a shape image of the cross section of the gas barrier coating layer, and 20 points are specified on the cross section of the gas barrier coating layer at intervals of 1 μm or more from the shape image. When calculating the hardness and the composite elastic modulus, the relationship between the contact depth and the contact projected area between the indenter and the sample was calibrated in advance using fused quartz as a standard sample. After that, the unloading curve in the 60-95% range of the maximum load at the time of unloading was analyzed by the Oliver-Pharr method, and the hardness and the composite elastic modulus of the gas barrier coating layer were calculated. The results are shown in Tables 1 and 2.

[0119] <Evaluation of Gas Barrier Laminate> (1) Visual inspection The gas barrier laminate obtained in each example was subjected to an external inspection. Specifically, after processing to a size of 1m x 100m, 10 samples of 10cm square were randomly cut out from the sample. If even one of the 10 samples had visible wrinkles, it was rated as "poor", and if none were visible, it was rated as "good". The results are shown in Tables 1 and 2.

[0120] (2) Preparation of laminate film A 60 μm-thick unstretched polypropylene film (CPP, product name "Treyfan ZK207", manufactured by Toray Advanced Film Co., Ltd.) was attached to the surface of the gas barrier coating layer of the gas barrier laminate obtained in each example using a two-component adhesive (product name "Takelac A-525 / Takenate A-52", manufactured by Mitsui Chemicals, Inc.) to produce a laminate film with a surface width of 210 mm.

[0121] (3) Measurement of oxygen permeability Using an oxygen permeability measuring device (product name "OX-TRAN2 / 20", manufactured by MOCON), the oxygen permeability (unit: cc / m) of the above laminate film was measured under conditions of a temperature of 30°C and a relative humidity of 70%. 2 The initial oxygen permeability (before re-entry) was measured as the initial oxygen permeability (day atm). The measurement was carried out in accordance with JIS K-7126-2. The results are shown in Tables 1 and 2.

[0122] (4) Oxygen barrier properties after retort processing (Preparation of test samples) A three-sided pouch having an opening was prepared using the laminate film prepared as described above. At this time, the three-sided pouch was formed by folding the laminate film so that the unstretched polypropylene films faced each other, and heat-sealing the unstretched polypropylene films. Then, tap water (city water) was poured from the opening to seal the opening of the three-sided pouch, thereby preparing a sealed body, and this sealed body was used as a test sample. (retort processing) The test sample obtained as described above was subjected to a heat treatment (retort treatment) at 121°C for 30 minutes. The oxygen permeability after the retort treatment (after retort) was measured in the same manner as the measurement of the initial oxygen permeability described above. The results are shown in Tables 1 and 2.

[0123] (5) Oxygen barrier properties after abuse The laminate film was subjected to abuse by carrying out a flex test (Gelbo flex test) and a stretch test as described below, and the oxygen permeability after abuse (after Gelbo) was measured in the same manner as the measurement of the initial oxygen permeability described above. The results are shown in Tables 1 and 2. (Bending test) A test sample measuring 297 mm long x 210 mm wide was cut out from the laminate film, and this test sample was attached to the fixed head of a Gelbo Flex Tester (manufactured by Tester Sangyo Co., Ltd.) so as to have a cylindrical shape measuring 87.5 mm in diameter x 210 mm, to prepare a cylindrical body. Then, both ends of the cylinder were held, and the initial gripping distance was set to 175 mm, the stroke was set to 87.5 mm, and a reciprocating motion in which a 440° twist was repeatedly applied was performed 10 times at a speed of 40 times / min to bend the cylinder.

[0124] [Table 1]

[0125] [Table 2]

[0126] As shown in Tables 1 and 2, the gas barrier laminates of the Examples had less wrinkling in the base layer and were less prone to cracking in the gas barrier coating layer than the gas barrier laminates of the Comparative Examples. In other words, the gas barrier laminates of the Examples have good appearance and barrier performance. [Explanation of symbols]

[0127] Reference Signs List 1: substrate layer, 3: metal oxide layer, 4: gas barrier coating layer, 10: gas barrier laminate, 20: packaging film, 21: sealant layer, 30: packaging container, 40: packaged product.

Claims

1. A substrate layer made of a resin, an anchor coat layer, a metal oxide layer, and a gas barrier coating layer, in this order; The thickness of the anchor coat layer is 30 to 300 nm, The gas barrier laminate, wherein the hardness of the gas barrier coating layer is 0.15 GPa or more and less than 1.10 GPa as measured by nanoindentation.

2. 2. The gas barrier laminate according to claim 1, wherein the gas barrier coating layer has a composite elastic modulus of 11 GPa or less.

3. A gas barrier laminate as described in claim 1, wherein the base layer is made of polypropylene resin.

4. The gas barrier laminate according to claim 1 , wherein the metal oxide layer contains at least one of aluminum oxide and silicon oxide.

5. A packaging film comprising the gas barrier laminate according to any one of claims 1 to 4 and a sealant layer.

6. A packaging container comprising the packaging film according to claim 5.

7. A packaging product comprising the packaging container according to claim 6 and a content filled in the packaging container.

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