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

Abstract

To provide a gas barrier laminate excellent in feed properties, rigidity and piercing properties and also excellent in the adhesion with another film, a packaging film, a packaging container and a packaged product.SOLUTION: A gas barrier laminate comprising a base material layer and a barrier layer, wherein the base material layer is a biaxially stretched film containing polyethylene, the base material layer comprises a first layer and a second layer in this order from a side far from the barrier layer, a probe descent temperature of the first layer is 140 °C. or higher and 160 °C. or lower, a probe descent temperature of the second layer is 180 °C. or higher and 210 °C. or lower, a thickness of the first layer is 2 μm or more and 10 μm or less, a thickness of the second layer is 15 μm or more and 25 μm or less, and a thickness of the base material layer is 20 μm or more and 30 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to 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 foods, medicines, etc. are required to have gas barrier properties that block the intrusion of water vapor, oxygen, and other gases that can cause deterioration of 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 substrate layer and a barrier layer, and various types of such gas barrier laminates have been known. For example, Patent Document 1 below proposes a gas barrier laminate comprising a resin substrate, an oxygen barrier coating film provided on at least one side of the resin substrate, and either or both of a primer layer and an inorganic oxide layer provided between the resin substrate and the oxygen barrier coating film, in which one side of the resin substrate is provided with a gas barrier film having a black area ratio of 0.15%, and even if the thickness of the coating for imparting oxygen barrier properties is thin, the inherent oxygen barrier properties are fully exhibited, exhibiting excellent gas barrier properties and good printability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 176824 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the gas barrier film described in Patent Document 1 has the following problems.

[0006] That is, the gas barrier film described in Patent Document 1 has room for improvement in terms of transportability, rigidity, puncture resistance, and adhesion to other films.

[0007] An object of the present disclosure is to provide a gas barrier laminate, a packaging film, a packaging container, and a packaging product that are excellent in transportability, rigidity, and puncture resistance, and also in adhesion to other films. [Means for solving the problem]

[0008] One aspect of the present disclosure provides a gas barrier laminate comprising a base layer and a barrier layer, wherein the base layer is a biaxially oriented film containing polyethylene, and the base layer comprises a first layer and a second layer, in this order from the side furthest from the barrier layer, wherein the first layer has a probe drop temperature of 140°C or higher and 160°C or lower, and the second layer has a probe drop temperature of 180°C or higher and 210°C or lower, the first layer has a thickness of 2 μm or higher and 10 μm or lower, the second layer has a thickness of 15 μm or higher and 25 μm or lower, and the base layer has a thickness of 20 μm or higher and 30 μm or lower. The gas barrier laminate of the present disclosure has excellent transportability, rigidity, and puncture resistance, and also has excellent adhesion to other films.

[0009] In the gas barrier laminate, the ratio of the thickness of the second layer to the thickness of the first layer may be greater than 4 and not greater than 12.

[0010] In the gas barrier laminate, it is preferable that the base layer further includes a third layer between the second layer and the barrier layer. In this case, warping of the substrate layer is suppressed, and peeling between the substrate layer and the barrier layer is less likely to occur.

[0011] In the gas barrier laminate, the barrier layer may further include a vapor-deposited layer of an inorganic material.

[0012] In the gas barrier laminate, it is preferable that the barrier layer further comprises an overcoat layer on the side of the vapor deposition layer opposite to the substrate layer, and the overcoat layer is a gas barrier coating layer. In this case, the gas barrier properties of the gas barrier laminate can be further improved.

[0013] In the gas barrier laminate, it is preferable that the overcoat layer is obtained using a composition for forming an overcoat layer containing a silicon compound and a water-soluble polymer, and that the silicon compound contains at least one of a silicon alkoxide, a hydrolyzate thereof, and a polycondensate thereof. In this case, the gas barrier properties of the gas barrier laminate can be effectively improved.

[0014] The gas barrier laminate preferably further comprises an anchor coat layer between the barrier layer and the substrate layer. In this case, the anchor coat layer can improve the adhesion between the barrier layer and the substrate layer.

[0015] In the gas barrier laminate, the anchor coat layer is preferably obtained using a composition containing an acrylic urethane resin. In this case, the heat resistance and the adhesion of the anchor coat layer to the substrate layer can be further improved.

[0016] Another aspect of the present disclosure provides a packaging film including the gas barrier laminate described above and a sealant layer. This packaging film includes the gas barrier laminate, which has excellent transportability, rigidity, and pierceability, and also has excellent adhesion to other films. Therefore, the packaging film of the present disclosure is suitable for producing packaging containers that are resistant to deformation when filled with contents, can suppress deterioration of gas barrier properties over a long period of time, and can be easily pierced with a straw.

[0017] The packaging film may further include an outer layer material that is provided on the opposite side of the gas barrier laminate from the sealant layer and that includes a paper substrate. Here, the packaging film of the present disclosure is useful when the outer layer material is bonded to the gas barrier laminate via an adhesive resin layer by extrusion lamination. Because the gas barrier laminate has excellent rigidity, even when an outer layer material including a paper base material is bonded to the gas barrier laminate via an adhesive resin layer by extrusion lamination, shrinkage of the base material layer due to the high temperature of the adhesive resin layer in a molten state is unlikely to occur, and the occurrence of cracks or breaks due to the accompanying shrinkage of the barrier layer and the occurrence of wrinkles in the base material layer are suppressed.

[0018] Yet another aspect of the present disclosure provides a packaging container including the packaging film. This packaging container is less likely to deform when filled with contents, prevents deterioration of gas barrier properties over a long period of time, and can be easily pierced with a straw.

[0019] Yet another aspect of the present disclosure provides a packaging product including the packaging container described above and a content filled in the packaging container. This packaging product includes the packaging container, which is resistant to deformation when filled with contents, can suppress deterioration of gas barrier properties over a long period of time, and can be easily pierced with a straw. Therefore, the packaging product of the present disclosure has a good appearance, suppresses deterioration of the quality of the contents over a long period of time, and can be easily pierced with a straw. [Effects of the Invention]

[0020] According to the present disclosure, there are provided a gas barrier laminate, a packaging film, a packaging container, and a packaging product that are excellent in transportability, rigidity, and puncture resistance, and also in adhesion to other films. [Brief explanation of the drawings]

[0021] [Figure 1]1 is a cross-sectional view showing one embodiment of a gas barrier laminate according to the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view showing one embodiment of a packaging film of the present disclosure. [Figure 3] 1 is a cross-sectional view illustrating one embodiment of a packaging product of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present disclosure will be described in detail.

[0023] <Gas barrier laminate> First, one embodiment of the gas barrier laminate of the present disclosure will be described with reference to Fig. 1. 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 100 includes a base layer 10 and a barrier layer 30. The base layer 10 is a biaxially stretched film containing polyethylene, and includes a first layer 11 and a second layer 12 in this order from the side furthest from the barrier layer 30.

[0024] The probe drop temperature of the first layer 11 is 140°C or more and 160°C or less, the probe drop temperature of the second layer 12 is 180°C or more and 210°C or less, the thickness T1 of the first layer 11 is 2 μm or more and 10 μm or less, the thickness T2 of the second layer 12 is 15 μm or more and 25 μm or less, and the thickness T of the base layer 10 is 20 μm or more and 30 μm or less.

[0025] The gas barrier laminate 100 may further include an overcoat layer 32. The gas barrier laminate 100 may also include an anchor coat layer 20 between the substrate layer 10 and the barrier layer 30. The base layer 10 may further include a third layer 13 on the opposite side of the second layer 12 from the first layer 11 .

[0026] This gas barrier laminate 100 has excellent transportability, rigidity and puncture resistance, and also has excellent adhesion to other films.

[0027] The substrate layer 10, the anchor coat layer 20, and the barrier layer 30 will be described in detail below.

[0028] (1) Base material layer The base material layer 10 is a layer that serves as a support for the barrier layer 30 and is a biaxially stretched film containing polyethylene. The base material layer 10 includes a first layer 11 and a second layer 12 in this order. The base material layer 10 may further include a third layer 13 on the opposite side of the second layer 12 from the first layer 11. Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, ethylene-(meth)acrylic acid copolymer, etc. These may be used alone or in combination of two or more.

[0029] The base layer 10 is a biaxially stretched film, stretched in two mutually perpendicular directions (MD and TD). By using a biaxially stretched film for the base layer 10, the gas barrier laminate 100 can be more easily pierced with a straw or the like. The heat resistance of the base layer 10 can also be improved, making the base layer 10 less susceptible to expansion and contraction when another film is laminated onto the base layer 10 by extrusion lamination, thereby suppressing the occurrence of cracks in the barrier layer 30 due to the expansion and contraction.

[0030] Here, the stretching ratios in the MD direction and the TD direction may be the same or different from each other, but if they are different from each other, the ratio (stretching ratio) of the stretching ratio in the TD direction (transverse direction) to the stretching ratio in the MD direction (longitudinal direction) may be 0.1 or more or 0.5 or more.

[0031] The stretch ratio may be 5 or less, or 2 or less.

[0032] The stretching ratio in the MD direction may be 2 times or more, 5 times or more, or 8 times or more, and may be 10 times or less, 8 times or less, or 5 times or less. The stretching ratio in the TD direction may be 2 times or more, 5 times or more, or 8 times or more, and may be 15 times or less, or 10 times or less. The thickness of the base layer 10 is 20 μm or more and 30 μm or less. When the thickness of the base layer 10 is 20 μm or more, the transportability and rigidity of the gas barrier laminate 100 can be further improved. When the thickness of the base layer 10 is 30 μm or less, the pierceability of the gas barrier laminate 100 can be further improved. From the viewpoint of further improving the transportability and rigidity of the gas barrier laminate 100, the thickness of the base layer 10 is preferably 22 μm or more, and more preferably 24 μm or more. From the viewpoint of further improving the pierceability of the gas barrier laminate 100, the thickness of the substrate layer 10 is preferably 28 μm or less, and more preferably 26 μm or less.

[0033] (1st layer) The first layer 11 is the layer of the base material layer 10 that is located farthest from the barrier layer 30, and is a layer for improving the pierceability and adhesion of the gas barrier laminate 100. The first layer 11 contains polyethylene. There are no particular restrictions on the polyethylene, but from the perspective of further improving the pierceability and adhesion of the gas barrier laminate 100, medium-density polyethylene is preferred.

[0034] The first layer 11 may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, and lubricants, as needed.

[0035] The probe descent temperature of the first layer 11 is 140° C. or higher and 160° C. or lower. When the probe descent temperature of the first layer 11 is 140° C. or higher, the rigidity and transportability of the gas barrier laminate 100 can be further improved. When the probe descent temperature of the first layer 11 is 160° C. or lower, the pierceability of the gas barrier laminate 100 and its adhesion to other films can be further improved. The probe drop temperature of the first layer 11 may be 145°C or higher, or 148°C or higher. The probe drop temperature of the first layer 11 may be 158°C or less, 155°C or less, 153°C or less, or 150°C or less.

[0036] The ratio R1 of the thickness T1 of the first layer 11 to the thickness T of the base layer 10 is not particularly limited as long as it is less than 1, and may be, for example, 0.05 or more, 0.08 or more, or 0.10 or more. The ratio R1 may be 0.25 or less, 0.20 or less, 0.17 or less, or 0.15 or less.

[0037] The thickness T1 of the first layer 11 is 2 μm or more and 10 μm or less. When the thickness T1 of the first layer 11 is 2 μm or more, the pierceability and adhesion of the gas barrier laminate 100 can be further improved. When the thickness T1 of the first layer 11 is 10 μm or less, the rigidity and transportability of the gas barrier laminate 100 can be further improved. The thickness T1 of the first layer 11 may be 3 μm or more, or may be 4 μm or more. The thickness T1 of the first layer 11 may be 8 μm or less, or 5 μm or less.

[0038] (2nd layer) The second layer 12 is a layer provided in the base layer 10 at a position closer to the barrier layer 30 than the first layer 11, and is a layer for improving the transportability and rigidity of the gas barrier laminate 100. The second layer 12 contains polyethylene. The polyethylene is not particularly limited, but from the viewpoint of further improving the transportability and rigidity of the gas barrier laminate 100, high-density polyethylene is preferred.

[0039] The probe descent temperature of the second layer 12 is 180° C. or higher and 210° C. or lower. When the probe descent temperature of the second layer 12 is 180° C. or higher, the transportability and rigidity of the gas barrier laminate 100 can be further improved. When the probe descent temperature of the second layer 12 is 210° C. or lower, the pierceability and adhesion of the gas barrier laminate 100 can be further improved. The probe drop temperature of the second layer 12 is 185°C or higher, and more preferably 190°C or higher. The probe drop temperature of the second layer 12 is preferably 205°C or less, and more preferably 200°C or less.

[0040] The second layer 12 may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, and lubricants, as needed.

[0041] When the base layer 10 is composed of a first layer 11 and a second layer 12, the ratio R2 of the thickness T2 of the second layer 12 to the thickness T of the base layer 10 is not particularly limited as long as it is less than 1, and may be, for example, 0.70 or more, 0.75 or more, 0.80 or more, or 0.83 or more. The ratio R2 may be 0.95 or less, 0.92 or less, or 0.90 or less.

[0042] When the base layer 10 is composed of a first layer 11, a second layer 12, and a third layer 13, the ratio R2 is not particularly limited as long as it is less than 1, and may be, for example, 0.50 or more, 0.60 or more, or 0.65 or more. The ratio R2 may be 0.85 or less, 0.82 or less, or 0.80 or less.

[0043] The thickness T2 of the second layer 12 is 15 μm or more and 25 μm or less. When the thickness T2 of the second layer 12 is 15 μm or more, the transportability and rigidity of the gas barrier laminate 100 can be further improved. When the thickness T2 of the second layer 12 is 25 μm or less, the pierceability of the gas barrier laminate 100 can be further improved. From the viewpoint of improving the transportability and rigidity of the gas barrier laminate 100, the thickness T2 of the second layer 12 is preferably greater than 18 μm, more preferably 19 μm or more, and particularly preferably 20 μm or more. From the viewpoint of improving the pierceability of the gas barrier laminate 100, the thickness T2 of the second layer 12 is preferably 24 μm or less, and more preferably 23 μm or less.

[0044] The ratio R of the thickness T2 of the second layer 12 to the thickness T1 of the first layer 11 is not particularly limited, and may be 4 or less, greater than 4 and less than 12, or greater than 12. When the ratio R is greater than 4 and equal to or less than 12, there is an advantage that film formation (formation of the first layer 11) becomes easy.

[0045] (3rd layer) When the base layer 10 includes the third layer 13, the third layer 13 can suppress warping of the base layer 10. The third layer 13 contains polyethylene. Although there are no particular limitations on the polyethylene, it is preferably medium-density polyethylene. In this case, the pierceability and adhesion of the gas barrier laminate 100 can be further improved.

[0046] The third layer 13 may contain additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, and a lubricant, as needed.

[0047] The probe drop temperature of the third layer 13 is not particularly limited, but is preferably 140°C or higher and 160°C or lower. The probe drop temperature of the third layer 13 may be 145°C or higher, or 148°C or higher. The probe drop temperature of the third layer 13 may be 158°C or less, 155°C or less, 153°C or less, or 150°C or less.

[0048] The third layer 13 may be made of the same material as the first layer 11 or a different material, but is preferably made of the same material. In this case, warping of the base material layer 10 is less likely to occur, and peeling between the base material layer 10 and the barrier layer 30 is more likely to be suppressed.

[0049] The ratio R3 of the thickness T3 of the third layer 13 to the thickness T of the base layer 10 is not particularly limited as long as it is less than 1, and may be, for example, 0.05 or more, 0.08 or more, or 0.10 or more. The ratio R3 may be 0.25 or less, 0.20 or less, 0.17 or less, or 0.15 or less. The ratio R3 may be the same as or different from the ratio R1, but from the viewpoint of suppressing warpage of the base layer 10, it is preferable that they are the same.

[0050] The thickness T3 of the third layer 13 is not particularly limited, but is preferably 2 μm or more and 10 μm or less. When the thickness T3 of the third layer 13 is 2 μm or more, the adhesion of the gas barrier laminate 100 can be further improved. When the thickness T3 of the third layer 13 is 10 μm or less, the puncture resistance of the gas barrier laminate 100 can be further improved. The thickness T3 of the third layer 13 may be 3 μm or more, or may be 4 μm or more. The thickness T3 of the third layer 13 may be 8 μm or less, or 5 μm or less. The thickness T3 of the third layer 13 may be the same as or different from the thickness T1 of the first layer 11, but from the viewpoint of suppressing warping of the base layer 10, it is preferable that they are the same.

[0051] (Anchor coat layer) The anchor coat layer 20 is a layer for further improving the adhesion between the substrate layer 10 and the barrier layer 30, and is provided between the substrate layer 10 and the barrier layer 30.

[0052] The material constituting the anchor coat layer 20 is not particularly limited as long as it can improve the adhesion between the base layer 10 and the barrier layer 30, but it is preferable that it is obtained using a composition containing a polyurethane resin. The polyurethane resin is formed by reacting, for example, an organosilane or organometallic compound with a polyol compound and an isocyanate compound. Examples of polyurethane resins include acrylic urethane resins, polyester polyurethane resins, and polyether polyurethane resins. Among these, as the polyurethane resin, from the viewpoint of improving heat resistance and adhesion of the anchor coat layer 20 to the base material layer 10, an acrylic urethane resin is preferable.

[0053] The thickness of the anchor coat layer 20 is not particularly limited, but is preferably in the range of 0.01 to 5 μm, more preferably in the range of 0.03 to 3 μm, and particularly preferably in the range of 0.05 to 2 μm. When the thickness of the anchor coat layer 20 is equal to or greater than the above-mentioned lower limit, the adhesion between the base layer 10 and the barrier layer 30 can be further improved, and the surface smoothness of the barrier layer 30 can be further improved. On the other hand, when the thickness of the anchor coat layer 20 is equal to or less than the above-mentioned upper limit, the mass proportion of the base layer 10 in the gas barrier laminate 100 increases, making it easier to increase the polyethylene content in the laminate 100.

[0054] (vapor deposited layer) The barrier layer 30 includes a vapor-deposited layer of an inorganic material. By including the barrier layer 30, the gas barrier laminate 100 can further improve the gas barrier properties. Examples of inorganic vapor-deposited layers include vapor-deposited layers of metals and vapor-deposited layers of inorganic oxides. Metals include aluminum and silicon. Inorganic oxides include metal oxides such as aluminum oxide and silicon oxide (silica). The inorganic vapor-deposited layer is preferably a vapor-deposited layer of an inorganic oxide, in which case the gas barrier laminate 100 can further reduce the environmental impact compared to a vapor-deposited layer of a metal. The vapor-deposited layer 31 may consist of a single layer or multiple layers.

[0055] The thickness of the vapor-deposited layer 31 is not particularly limited, but is preferably 5 nm or more. In this case, the gas barrier properties of the gas barrier laminate 100 are further improved compared to when the thickness of the vapor-deposited layer 31 is less than 5 nm. The thickness of the vapor-deposited layer 31 is more preferably 8 nm or more, and particularly preferably 10 nm or more. The thickness of the vapor-deposited layer 31 is preferably 80 nm or less. In this case, the flexibility of the gas barrier laminate 100 is improved and the gas barrier properties of the gas barrier laminate 100 after abuse can be further improved compared to when the thickness of the vapor-deposited layer 31 exceeds 80 nm. The gas barrier properties of the gas barrier laminate 100 after retort treatment can also be further improved. The thickness of the vapor-deposited layer 31 is more preferably 70 nm or less, and particularly preferably 60 nm or less.

[0056] (Overcoat layer) The overcoat layer 32 is a layer that covers the vapor-deposited layer 31, and is preferably a gas barrier coating layer. In this case, the gas barrier properties of the gas barrier laminate 100 can be further improved. The gas barrier coating layer can be obtained using a composition for forming an overcoat layer, for example, containing a silicon compound and a water-soluble polymer. Here, the silicon compound preferably contains at least one of silicon alkoxide, its hydrolyzate, and its polycondensate. In this case, the gas barrier properties of the gas barrier laminate 100 can be effectively improved.

[0057] Silicon alkoxides are represented by the following general formula (1): Si(OR 1 )4. Si(OR 1 )4······(1) In general formula (1), R 1 represents an alkyl group or -C2H4OCH3. Examples of alkyl groups include methyl and ethyl groups. Among these, the ethyl group is preferred. In this case, the silicon alkoxide becomes tetraethoxysilane, which becomes relatively stable in an aqueous solvent after hydrolysis.

[0058] Examples of water-soluble polymers include polyvinyl alcohol (PVA), modified products thereof, ethylene-vinyl alcohol copolymers, and polyacrylic acid. These can be used alone or in combination of two or more. Among these, polyvinyl alcohol or modified products thereof are preferred as the water-soluble polymer. In this case, this composition can impart better gas barrier properties to the gas barrier laminate 100 upon curing. Furthermore, even after curing, this composition can impart better flexibility to the gas barrier laminate 100, further improving the gas barrier properties after abuse.

[0059] When the water-soluble polymer is composed of polyvinyl alcohol 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 100, it is preferably 95% or more, and may be 100%.

[0060] 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 properties of the gas barrier laminate 100. The degree of polymerization of the water-soluble polymer is preferably 450 to 2400.

[0061] The content of the water-soluble polymer in the solid content is not particularly limited, but is preferably 40% by mass or more when the silicon alkoxide is converted to SiO2. In this case, the flexibility of the gas barrier laminate 100 can be further improved. Therefore, the gas barrier properties of the gas barrier laminate 100 can be further improved even after abuse.

[0062] The content of the water-soluble polymer in the solid content is preferably 43% by mass or more, more preferably 44% by mass or more, and particularly preferably 45% by mass or more. When the content of the water-soluble polymer in the solid content is 43% 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 43% by mass.

[0063] The content of the water-soluble polymer in the solid content may be less than 100% by mass, preferably 85% by mass or less, and more preferably 75% by mass or less. When the content of the water-soluble polymer in the solid content is 85% by mass or less, the interlayer adhesion of the gas barrier laminate 100 after retort treatment can be further improved compared to when the content of the water-soluble polymer in the solid content exceeds 85% by mass.

[0064] The composition for forming an overcoat layer may further contain a silane coupling agent as a curing agent.

[0065] 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 represents an alkyl group or -C2H4OCH3. In this case, it is possible to improve the adhesion between the overcoat layer 32 and the vapor deposition layer 31, and delamination between layers in the gas barrier laminate 100 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 these, an isocyanate group is preferred as the monovalent organic functional group. In this case, the composition can have better hot water resistance upon curing, and can impart greater laminate strength to the gas barrier laminate 100 even after retort treatment. R 3Examples of the alkyl group represented by the formula (I) include a methyl group and an ethyl group. Among these, a methyl group is preferred. In this case, hydrolysis occurs quickly. n represents an integer of 1 or greater. When n is 1, the silane coupling agent represents a monomer, whereas when n is 2 or greater, the silane coupling agent represents a polymer. n is preferably 3. In this case, the hot water resistance of the overcoat layer 32 can be further improved, and it becomes possible to impart greater laminate strength to the gas barrier laminate 100 even after retort treatment.

[0066] Examples of silane coupling agents 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.

[0067] The content of the silane coupling agent in the solid content is not particularly limited, but is preferably 3% by mass or more, more preferably 5% by mass or more, and particularly preferably 7% by mass or more. In this case, the gas barrier laminate 100 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 3% by mass. The content of the silane coupling agent in the solid content is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 12% by mass or less. In this case, the silane coupling agent is less likely to bleed out and contaminate the surface than when 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 It is calculated in terms of the mass of Si(OH)3.

[0068] (Other components in solids) The solid content may further contain known additives such as dispersants, stabilizers, viscosity adjusters, and colorants as needed, within the range that does not impair the gas barrier properties of the overcoat layer 32 .

[0069] (Total content of ingredients in solids) The total content of silicon alkoxide or its hydrolysate, water-soluble polymer, and silane coupling agent in the solid content is not particularly limited, but is usually 95% by mass or more, preferably 97% by mass or more, and may be 100% by mass.

[0070] (liquid) An aqueous medium is usually used as the liquid for dissolving or dispersing the solid content. 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.

[0071] The aqueous medium is preferably an aqueous medium consisting of only water or an aqueous medium containing water as the main component. When the aqueous medium contains water as the main component, the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more.

[0072] The thickness of the overcoat layer 32 is not particularly limited, but is preferably 50 nm or more. In this case, the gas barrier properties of the gas barrier laminate 100 are further improved compared to when the thickness of the overcoat layer 32 is less than 50 nm.

[0073] From the viewpoint of improving the gas barrier property, the thickness of the overcoat layer 32 is more preferably 100 nm or more, and particularly preferably 200 nm or more. On the other hand, the thickness of the overcoat layer 32 is preferably 700 nm or less. Compared to when the thickness of the overcoat layer 32 exceeds 700 nm, the flexibility of the gas barrier laminate 100 is further improved, and the gas barrier properties of the gas barrier laminate 100 after abuse can be further improved. In addition, the gas barrier properties of the gas barrier laminate 100 after retort treatment can also be further improved.

[0074] From the viewpoint of further improving the flexibility of the gas barrier laminate 100, the thickness of the overcoat layer 32 is more preferably 500 nm or less, and particularly preferably 400 nm or less.

[0075] <Method of manufacturing gas barrier laminate> Next, a method for producing the gas barrier laminate 100 will be described.

[0076] First, the base layer 10 is prepared. The base layer 10 can be formed by co-extrusion using, for example, polyethylene to form the first layer 11, the second layer 12, and, if necessary, the third layer 13.

[0077] Next, the anchor coat layer 20 is formed on one surface of the base material layer 10 . Specifically, the anchor coat layer 20 is formed by applying a composition for forming the anchor coat layer 20 onto one surface of the base layer 10 and then heating and drying the composition. At this time, the heating temperature is, for example, 50 to 200°C, and the drying time is, for example, about 10 seconds to 10 minutes.

[0078] Next, a vapor deposition layer 31 is formed on the anchor coat layer 20 . The deposition layer 31 can be formed by, for example, a vacuum film formation method. Examples of vacuum film formation methods include physical vapor deposition and chemical vapor deposition. Examples of physical vapor deposition methods include vacuum deposition, sputtering deposition, and ion plating. As a physical vapor deposition method, vacuum deposition is particularly preferably used. Examples of vacuum deposition methods include resistance heating vacuum deposition, EB (Electron Beam) heating vacuum deposition, and induction heating vacuum deposition. Examples of chemical vapor deposition methods include thermal CVD, plasma CVD, and photo CVD.

[0079] Next, an overcoat layer 32 is formed on the vapor deposition layer 31 .

[0080] The overcoat layer 32 can be formed, for example, by applying a composition for forming an overcoat layer, which contains a solid component and a liquid such as an aqueous solvent, onto the vapor deposition layer 31, and then heating the composition.

[0081] The composition for forming the overcoat layer can be applied by a known method, specifically, a wet film formation method such as gravure coating, dip coating, reverse coating, wire bar coating, or die coating.

[0082] The heating temperature and heating time may be set so that the solid content in the composition for forming the overcoat layer can be cured and the liquid such as the aqueous medium can be removed at the same time. The heating temperature may be, for example, 80 to 250° C., and the heating time may be, for example, 3 seconds to 10 minutes.

[0083] In this manner, the gas barrier laminate 100 is obtained.

[0084] <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.

[0085] 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 200 includes a gas barrier laminate 100 and a sealant layer 210 laminated on the gas barrier laminate 100. In Fig. 2, the sealant layer 210 is disposed on the overcoat layer 32 side of the base material layer 10 of the gas barrier laminate 100. The packaging film 200 may further include an outer layer material 220 including a paper substrate, which is provided on the opposite side of the gas barrier laminate 100 to the sealant layer 210 . The packaging film 200 may have a printed layer 240 on the outer layer material 220. When the printed layer 240 is disposed on the opposite side of the outer layer material 220 from the gas barrier laminate 100 in the packaging film 200, the packaging film 200 may further include a protective layer 250 that protects the printed layer 240. The gas barrier laminate 100 and the outer layer material 220 are bonded together by an adhesive layer 230, as shown in Fig. 2. The gas barrier laminate 100 and the sealant layer 210 may be bonded together directly as shown in Fig. 2, or may be bonded together by an adhesive layer.

[0086] This packaging film 200 includes the gas barrier laminate 100, which has excellent transportability, rigidity, and piercing resistance, and also has excellent adhesion to other films. Therefore, the packaging film 200 is resistant to deformation when filled with contents, can suppress deterioration of gas barrier properties over a long period of time, and is suitable for producing packaging containers that can be easily pierced with a straw.

[0087] The sealant layer 210, the outer layer material 220, the adhesive layer 230, the printing layer 240, and the protective layer 250 will be described in detail below.

[0088] (sealant layer) The sealant layer 210 is a layer that is bonded to another sealant layer 210 by heating and pressurizing when a packaging container is produced using the laminate 100. The sealant layer 210 may be arranged on either the base material layer 10 side or the barrier layer 30 side of the gas barrier laminate 100, but is preferably arranged on the base material layer 10 side, particularly when the contents to be placed in the packaging container are liquid, as this provides excellent water resistance.

[0089] The sealant layer 210 may be a sealant film containing a resin. Such resins include thermoplastic resins such as polyolefin resins and polyester resins, with polyolefin resins being the most commonly used. The polyolefin resin may be polyethylene, polypropylene, a mixture thereof, etc. The material of the sealant layer 210 may be appropriately selected from the above-mentioned thermoplastic resins depending on the intended use and the temperature conditions of the boiling treatment, retort treatment, etc. Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-(meth)acrylic acid copolymer. These may be used alone or in combination of two or more. Examples of polypropylene include homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, etc. These may be used alone or in combination of two or more. From the viewpoint of improving the recyclability of the packaging film 200, it is preferable that the polyolefin resin contains polyethylene.

[0090] The sealant layer 210 may further contain additives such as flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and light-shielding pigments, as required.

[0091] The thermoplastic resin constituting the sealant layer 210 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.

[0092] The sealant layer 210 may be composed of a single layer or a laminate of multiple layers. When the plurality of layers is, for example, three layers, the stack of the plurality of layers may be comprised of a first outer layer, a middle layer and a second outer layer.

[0093] The sealant layer 210 preferably has a melting point lower than that of the outer substrate layer 10. In this case, when the laminate 100 is heat-sealed, the sealant layer 210 can be heat-sealed while suppressing melting of the substrate layer 10. Furthermore, by heating the laminate 100, the substrate layer 10 and the sealant layer 210 can be easily separated, and material recycling of each of the substrate layer 10 and the sealant layer 210 can be easily performed.

[0094] The thickness of the sealant layer 210 is not particularly limited and is adjusted appropriately depending on the application of the laminate 100. The thickness of the sealant layer 210 may be, for example, 10 μm or more, 25 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. The thickness of the sealant layer 210 may also be 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, or 50 μm or less.

[0095] (outer layer material) The outer layer material 220 includes a paper base material. The paper base material is a base material containing paper, and paper refers to a material containing plant-derived pulp as a main component, where the main component refers to a component containing plant-derived pulp at 50% by mass or more. The packaging film 200 including the outer layer material 220 can contribute to reducing the amount of plastic material used.

[0096] Specific examples of paper substrates include fine paper, special fine paper, coated paper, art paper, cast coated paper, construction paper, kraft paper, and glassine paper.

[0097] The outer layer material 220 may or may not further have a coating layer on the surface of the paper substrate. If the outer layer material 220 further has a protective layer, it can prevent the anchor coat layer 20 from penetrating into the paper substrate and also serve as a sealant to fill in unevenness in the paper substrate, allowing the anchor coat layer 20 to be formed uniformly without defects. The coating layer may further contain a binder resin and, if necessary, a filler. Examples of binder resins include polyolefin resins, various copolymers such as styrene-butadiene copolymers and styrene-acrylic copolymers, polyvinyl alcohol resins, and cellulose resins. Among these, polyolefin resins are preferred. Examples of fillers include kaolin, calcium carbonate, talc, and mica. If the outer layer material 220 does not have a coating layer, discoloration of the paper due to the retort treatment of the packaging film 200 is less likely to occur. The paper substrate may be made up of a single layer or multiple layers. The outer layer material 220 may have a through-hole as an opening for piercing a straw.

[0098] In the packaging film 200, the outer layer material 220 is useful when it is bonded to the gas barrier laminate 100 by extrusion lamination with an adhesive resin layer. This is because the gas barrier laminate 100 has excellent rigidity, and therefore, even when the outer layer material 220 including a paper base material is bonded to the gas barrier laminate 100 by extrusion lamination with the adhesive layer 230 made of an adhesive resin layer, shrinkage of the base material layer 10 due to the high temperature of the adhesive resin layer in a molten state is unlikely to occur, and the occurrence of cracks or breaks due to the resulting shrinkage of the barrier layer 30 and the occurrence of wrinkles in the base material layer 10 are suppressed.

[0099] The thickness of the outer layer material 220 is not particularly limited. From the viewpoint of reducing material consumption to reduce environmental impact and from the viewpoint of obtaining excellent heat resistance, impact resistance, and gas barrier properties, the thickness of the outer layer material 220 may be 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, or 40 μm or more. Furthermore, from the viewpoint of reducing the amount of plastic used and reducing environmental impact, the thickness of the outer layer material 220 may be 100 μm or less, 60 μm or less, or 50 μm or less.

[0100] The basis weight of the paper substrate is not particularly limited. From the viewpoint of reducing materials to reduce the environmental load and from the viewpoint of obtaining excellent heat resistance, impact resistance, and gas barrier properties, the basis weight of the paper substrate is 40 g / m 2 More than 60g / m 2 or more than 80g / m 2 In addition, the basis weight of the paper base material should be 160 g / m2 from the viewpoint of reducing the amount of plastic used and reducing the environmental impact. 2 Below 140g / m 2 or less, or 120 g / m 2 The following is fine.

[0101] (adhesive layer) The adhesive layer 230 may be, for example, an adhesive layer containing an adhesive resin (hereinafter also referred to as an "adhesive resin layer").

[0102] The adhesive resin layer may be an extruded or non-extruded resin layer. The adhesive resin is a heat-sealable adhesive thermoplastic resin that can be melted by heat and fused to each other. Examples of adhesive resins include polyolefin resins and acid-modified polyolefin resins obtained by modifying polyolefin resins with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, and the like. Examples of polyolefin resins include polyethylene, polypropylene, and methylpentene polymers. Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-(meth)acrylic acid copolymer. These may be used alone or in combination of two or more. Examples of polypropylene include homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, etc. These may be used alone or in combination of two or more. From the viewpoint of improving recyclability, the adhesive resin is preferably polyethylene.

[0103] The adhesive layer 230 may be an adhesive layer formed using an adhesive. Examples of the adhesive include known adhesives such as urethane adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, isocyanate adhesives, etc. When the packaging film 200 is used for retort applications, the adhesive preferably includes a urethane adhesive, and as the urethane adhesive, a two-component curing urethane adhesive that is resistant to retort treatment can preferably be used. The adhesive may be an adhesive containing an organic solvent or an adhesive containing no organic solvent, but from the viewpoint of reducing the environmental load, an adhesive containing no organic solvent (solvent-free adhesive) is preferred.

[0104] The thickness of the adhesive layer 230 is not particularly limited and may be, for example, 1 μm or more. By making the thickness of the adhesive layer 230 1 μm or more, sufficient adhesive strength can be obtained. The thickness of the adhesive layer 230 may be 2 μm or more. The thickness of adhesive layer 230 may be 50 μm or less, 5 μm or less, or 3 μm or less.

[0105] When the sealant layer 210 and the gas barrier laminate 100 are bonded via an adhesive layer, the same adhesive layer as the adhesive layer 230 can be used as the adhesive layer.

[0106] (Printing layer) The printing layer 240 is a layer that displays letters, pictures, symbols, combinations thereof, etc. In Fig. 2, the printing layer 240 is provided on the side of the outer layer material 220 opposite the sealant layer 210, but it may also be provided on the sealant layer 210 side. The printing layer 240 is obtained using ink. The printed layer 240 may be provided on only a portion of the surface of the outer layer material 220, or may be provided on the entire surface of the outer layer material 220.

[0107] The printing layer 240 can be formed by, for example, gravure printing, offset printing, flexible printing, or the like. Examples of the printing method include a conventionally known printing method such as a printing method.

[0108] (protective layer) The protective layer 250 is a layer that protects the printed layer 240 and contains a resin. The resin may be a polyolefin resin. Examples of polyolefin resins include polyethylene, polypropylene, and methylpentene polymers. Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-(meth)acrylic acid copolymer. These may be used alone or in combination of two or more. Examples of polypropylene include homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, etc. These may be used alone or in combination of two or more. From the viewpoint of improving the recyclability of the packaging film 200, the resin is preferably polyethylene.

[0109] <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 designated by the same reference numerals, and redundant description will be omitted. As shown in Fig. 3, a packaged product 400 includes a packaging container 300 and a content C filled in the packaging container 300. The packaging container 300 shown in Fig. 3 is obtained by using a pair of packaging films 200 and heat-sealing the peripheral edges of the packaging films 200 with the sealant layers 210 facing each other.

[0110] This packaged product 400 includes a packaging container 300 that is resistant to deformation when filled with the contents C, can prevent deterioration in gas barrier properties over a long period of time, and can be easily pierced with a straw. Therefore, the packaged product 400 has a good appearance, prevents deterioration in the quality of the contents over a long period of time, and can be easily pierced with a straw.

[0111] The packaging container 300 can also be obtained by folding one packaging film 200 and heat-sealing the periphery of the packaging film 200 with the sealant layers 210 facing each other.

[0112] Examples of the packaging container 300 include a packaging bag, a laminated tube container, and a liquid paper container.

[0113] The contents C are not particularly limited, and examples of the contents C include food, liquid, medicine, and electronic parts.

[0114] The present disclosure is not limited to the above-described embodiment. For example, in the above-described embodiment, the sealant layer 210 in the packaging film 200 is disposed on the overcoat layer 32 side of the base layer 10 of the gas barrier laminate 100. However, the sealant layer 210 may be disposed on the opposite side of the base layer 10 from the overcoat layer 32. [Example]

[0115] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0116] In the examples and comparative examples, the layer thickness and the probe descending temperature were measured as follows. (1) Thickness The thicknesses of the first, second, third and vapor deposition layers of the base layer of the gas barrier laminate were measured using a thickness measuring instrument (manufactured by Mitutoyo Corporation, product name "Digital Outside Micrometer", model "OMV-25DM").

[0117] (2) Tip temperature drop (Preparation of measurement samples) First, a measurement sample was prepared as follows. The front and back surfaces of the gas barrier laminate were each subjected to a corona treatment at 0.20 kW using a corona treatment machine (product name: CT-0212) manufactured by Kasuga Electric Works. Next, the gas barrier laminate was cut into strips with a razor along its thickness direction, measuring 1.0 mm in base and 5.0 mm in length, to obtain cut pieces. The cut pieces were embedded in a photocurable resin, which was then cured using a halogen lamp (Kenko Tokina, product name: KTX-100R) to obtain block pieces. The photocurable resin used was D-800 (product name) manufactured by Toa Gosei Co., Ltd. Next, the block pieces were fixed in an insert for an AFM sample holder, and cross-sections of the block pieces were performed using a glass knife at room temperature (25°C) using a cross-section cutting device. Finally, final cross-section cutting was performed using a diamond knife at a low temperature (-40°C) using the cross-section cutting device, with a cutting speed of 1.0 mm / s and a cut film thickness of 100 nm. Cutting was terminated when a mirror surface was obtained, yielding a cross-sectioned gas barrier laminate sample for measurement. The cross-section cutting devices used were an ultramicrotome (Leica, product name: EM UC7) and a cryosystem (Leica, product name: EM FC7). The cutting direction of the knife was parallel to the thickness direction of the cut piece and perpendicular to the long side of the cut piece. The measurement sample was fixed in an insert for the AFM sample holder and used for the probe fall temperature measurement.

[0118] (measurement) First, we prepared a probe fall temperature measurement device including an atomic force microscope (AFM) MFP-3D-SA (trade name) manufactured by Oxford Instruments, a local thermal analysis option Ztherm System (trade name), and a cantilever (probe) AN2-200 (trade name) manufactured by Anasys Instruments with a spring constant of 0.5 to 3.5 N / m. Next, using the probe drop temperature measurement device, probe drop temperature measurements and cross-sectional shape measurements were performed on the first, second, and third layers of the base layer. The measurement mode was AC mode (tapping mode) for cross-sectional shape measurements of the first, second, and third layers of the base layer, and contact mode for probe drop temperature measurements. The probe drop temperature measurements were performed on a 10 μm × 10 μm region that included the center of the cross section (the intersection of the diagonals) of each of the first, second, and third layers of the base layer.

[0119] At this time, when setting the cantilever contact pressure (change in cantilever deflection), the deflection voltage change was set to 0.2 V, the voltage application rate (heating rate) was set to 0.5 V / sec, and the maximum applied voltage was set to 5.5 V. After detrend correction, the cross sections of the first, second, and third layers of the base material layer were heated. After the cross sections expanded and the cantilever position rose, the cross sections were further heated to soften them, and the measurement was terminated when the cantilever position descended by 10 nm.

[0120] The voltage applied at the point where the vertical height (Z displacement) of the cantilever was maximum was taken as the voltage applied at the probe descent point, and the voltage value was read.

[0121] To calculate the probe drop temperatures of the first, second, and third layers of the base material layer from the above voltage values, calibration curves were created to match the measurement conditions of the first, second, and third layers of the base material layer. The calibration samples were the following four types of polymer materials whose melting points (melting peak temperatures) had been measured in advance using a differential scanning calorimeter (DSC), and samples were used that were prepared in an environment below their glass transition temperatures. Polycaprolactone pellets (melting point: 60°C) Low-density polyethylene pellets (melting point: 112°C) Polypropylene pellets (melting point: 166°C) Biaxially stretched polyethylene terephthalate film (melting point: 255°C) The measurement conditions were a voltage application rate (heating rate) of 0.5 V / s, and a maximum applied voltage of 3.5 V for polycaprolactone, 5 V for low-density polyethylene, 6 V for polypropylene, and 7.8 V for polyethylene terephthalate. The cantilever contact pressure (change in cantilever deflection) was set with a deflection voltage change of 0.2 V. After detrend correction, each surface of the calibration sample was heated and the applied voltage at the probe descent point was measured. The applied voltage at the probe descent point was measured 10 times at different measurement positions on the calibration sample. A calibration curve was created by approximating the average applied voltage at the probe descent point and the melting point (melting peak temperature) measured by DSC measurement with a cubic function using the least-squares method. This calibration curve was used as the calibration curve.

[0122] Using a calibration curve of applied voltage and temperature, the temperatures corresponding to the applied voltage at the probe descent points on the first, second and third layers of the substrate layer were determined, and these temperatures were taken as the probe descent temperatures.

[0123] <Preparation of water-based overcoat solution> An aqueous overcoat solution used for evaluating transportability was prepared as follows. First, tetraethoxysilane (trade name: KBE04, solid content: 100%, manufactured by Shin-Etsu Chemical Co., Ltd., hereinafter also referred to as "TEOS") as a silicon alkoxide, methanol (manufactured by Kanto Chemical Co., Ltd.), and 0.1N hydrochloric acid (manufactured by Kanto Chemical Co., Ltd.) were mixed in a mass ratio of 45 / 15 / 40, and the resulting hydrolyzed solution (TEOS hydrolysis solution) was mixed with a 5 mass% aqueous solution of polyvinyl alcohol (trade name: Kuraray Poval 60-98, manufactured by Kuraray Co., Ltd., hereinafter also referred to as "PVA") and 1,3,5-tris(3-methoxysilylpropyl) isocyanurate as a silane coupling agent (SC agent) in a water / IPA=1 / 1 mass ratio mixture solution to a solid content of 5 mass% (R 2 The aqueous overcoat solution was prepared by diluting and adjusting the solution so that the solid content was 100, and then mixing the solution containing TEOS (SiO2 equivalent) and isocyanurate silane (R Si(OH)3 equivalent). 2The mass ratio of Si(OH)3 (equivalent value) to PVA was adjusted to 40 / 5 / 55.

[0124] Example 1 The first layer is made of medium density polyethylene (density: 0.93 g / cm 3 ) and the second layer is made of high-density polyethylene (density: 0.96 g / cm 3 ) were prepared and co-extruded to prepare an unstretched sheet. This unstretched sheet was stretched 4 times in the MD direction and then 3 times in the TD direction to obtain a base layer made of a biaxially stretched film having a first layer and a second layer. The thickness T1 of the first layer, the thickness T2 of the second layer, and the thicknesses T, T1 / T, T2 / T, and T2 / T1 of the base layer were as shown in Table 1. Furthermore, the probe drop temperatures of the first and second layers were measured and were found to be 140° C. and 210° C., respectively, as shown in Table 1. Next, while the base layer is transported and wound up on a winding roll, SiO 2 is applied to the second layer of the base layer so as to have a film thickness of 12 nm. x A barrier layer consisting of a SiO film (a vapor-deposited layer of inorganic oxide) was formed. x The film was formed by evaporating an aluminum ingot with electron beam heating using a vacuum deposition device at a pressure of 1.2 × 10 -2 This was done by introducing oxygen to a pressure of 10 Pa.

[0125] In this manner, a gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor-deposited layer)) was obtained.

[0126] Example 2 The polyethylene forming the second layer is high-density polyethylene (density: 0.95 g / cm 3 A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thicknesses T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 1.

[0127] Example 3 The polyethylene forming the first layer is medium density polyethylene (density: 0.94 g / cm 3 A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thicknesses T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 1.

[0128] (Examples 4 to 5) A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 1.

[0129] (Comparative Example 1) The polyethylene forming the first layer is high-density polyethylene (density: 0.95 g / cm 3 A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thicknesses T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 1.

[0130] (Comparative Example 2) The polyethylene forming the second layer was a medium density polyethylene film (density: 0.94 g / cm 3 A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thicknesses T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 2.

[0131] (Comparative Examples 3 to 6) A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were each set as shown in Table 2.

[0132] (Comparative Example 7) The polyethylene forming the first layer is high-density polyethylene (density: 0.95 g / cm 3 ), and the polyethylene forming the second layer is medium density polyethylene (density: 0.93 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 2, respectively. A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 2.

[0133] (Comparative Example 8) The polyethylene forming the first layer is high-density polyethylene (density: 0.96 g / cm 3 ), and the polyethylene forming the second layer is medium density polyethylene (density: 0.94 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3, respectively. A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3.

[0134] (Comparative Examples 9 to 10) The polyethylene forming the first layer is high-density polyethylene (density: 0.96 g / cm 3 ), and the polyethylene forming the second layer is medium density polyethylene (density: 0.93 g / cm 3), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3, respectively. A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3.

[0135] (Comparative Example 11) The polyethylene forming the first layer is high-density polyethylene (density: 0.96 g / cm 3 ), the second layer was not formed, and the thickness T1 of the first layer, the thickness T2 of the second layer, the thicknesses T, T1 / T, T2 / T, T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3, respectively. A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that

[0136] (Comparative Example 12) A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3.

[0137] (Comparative Example 13) A gas barrier laminate (base layer (first layer / second layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 1, except that the second layer was not formed, and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T, T1 / T, T2 / T, and T2 / T1 of the base layer, the probe descent temperature of the first layer, and the probe descent temperature of the second layer were set as shown in Table 3.

[0138] Example 6 The first layer is made of medium density polyethylene (density: 0.93 g / cm 3 ) and the second layer is made of high-density polyethylene (density: 0.95 g / cm 3 ) and the third layer is made of medium density polyethylene (density: 0.93 g / cm 3) were prepared and co-extruded to prepare an unstretched sheet. This unstretched sheet was stretched 4 times in the MD direction and then 3 times in the TD direction to obtain a base layer made of a biaxially stretched film having a first layer, a second layer, and a third layer. The thicknesses of the first layer (T1), second layer (T2), third layer (T3), and base layer thicknesses (T, T1 / T, T2 / T, and T2 / T1) were as shown in Table 4. Furthermore, the probe drop temperatures of the first, second and third layers were measured, and the probe drop temperatures of the first, second and third layers were as shown in Table 4. Next, while the base layer is transported and wound up on a winding roll, SiO 3 is applied to the third layer of the base layer so as to have a film thickness of 12 nm. x A barrier layer consisting of a SiO film (a vapor-deposited layer of inorganic oxide) was formed. x The film was formed by using an electron beam heating type vacuum deposition apparatus, by introducing oxygen while evaporating a silicon ingot by electron beam heating.

[0139] In this manner, a gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained.

[0140] Example 7 The first layer is made of medium density polyethylene (density: 0.94 g / cm 3 ) and the second layer is made of high-density polyethylene (density: 0.96 g / cm 3 ) and the third layer is made of medium density polyethylene (density: 0.94 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4, and a gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 6, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4.

[0141] (Examples 8 to 9, Comparative Examples 14, 17 to 20) The first layer is made of medium density polyethylene (density: 0.93 g / cm 3) and the second layer is made of high-density polyethylene (density: 0.96 g / cm 3 ) and the third layer is made of medium density polyethylene (density: 0.93 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4 or Table 5, respectively. A gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 6, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4 or Table 5.

[0142] (Comparative Example 15) The first layer is made of high-density polyethylene (density: 0.95 g / cm 3 ) and the second layer is made of high-density polyethylene (density: 0.96 g / cm 3 ) and the third layer is made of high-density polyethylene (density: 0.95 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4, and a gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 6, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe drop temperatures of the first layer, second layer and third layer were as shown in Table 4.

[0143] (Comparative Example 16) The first layer is made of medium density polyethylene (density: 0.93 g / cm 3 ) and medium density polyethylene (density: 0.94 g / cm ) that forms the second layer. 3 ) and the third layer is made of medium density polyethylene (density: 0.93 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe descent temperatures of the first layer, second layer and third layer were as shown in Table 5, and a gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 6, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe descent temperatures of the first layer, second layer and third layer were as shown in Table 5.

[0144] (Comparative Example 21) The first layer is made of medium density polyethylene (density: 0.94 g / cm 3 ) and the second layer is made of high-density polyethylene (density: 0.95 g / cm 3 ) and the third layer is made of medium density polyethylene (density: 0.94 g / cm 3 ), and the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe descent temperatures of the first layer, second layer and third layer were as shown in Table 5, and a gas barrier laminate (base layer (first layer / second layer / third layer) / barrier layer (vapor deposition layer)) was obtained in the same manner as in Example 6, except that the thickness T1 of the first layer, the thickness T2 of the second layer, the thickness T3 of the third layer, the thickness T of the base layer, the values ​​of T1 / T, T2 / T and T2 / T1, and the probe descent temperatures of the first layer, second layer and third layer were as shown in Table 5.

[0145] <Evaluation> The gas barrier laminate was evaluated for transportability, rigidity, piercing resistance and adhesion as follows.

[0146] (1) Transportability The gas barrier laminates obtained in the Examples and Comparative Examples were transported at a transport speed of 100 m / s and a tension of 50 N / m on a take-up roll, and while being wound up on a take-up roll, the aqueous overcoat liquid prepared as described above was applied onto the vapor deposition layer. The laminate was then heated in an oven at 100°C for 10 seconds to form an overcoat layer with a thickness of 300 nm, and the resulting raw film was wound up on a roll. The surface of the rolled film was observed under an optical microscope to check for wrinkles on the film and cracks or wrinkles in the vapor-deposited layer. The transportability was evaluated based on the following criteria. The results are shown in Tables 1 to 5. (standard) ◎: No cracks or breaks were observed in the deposition layer, and no wrinkles were observed in the raw film. ◯: Breaks and cracks were observed in the vapor deposition layer, but no wrinkles were observed in the raw film. ×: Breaks and cracks were observed in the vapor deposition layer, and wrinkles were observed in the raw film.

[0147] (2) Rigidity In order to evaluate the rigidity of the gas barrier laminates obtained in the Examples and Comparative Examples, brick-shaped paper containers for liquid storage were produced as follows. First, a film having a density of 0.918 g / cm was extrusion laminated on the surface of the gas barrier laminate opposite to the deposition layer. 3 A sealant layer (thickness: 30 μm) made of low density polyethylene was formed to obtain an inner layer material. On the other hand, a paper substrate (basis weight: 260 g / m) with a through hole (diameter 6 mm) formed as a straw piercing opening was used. 2 A coating layer (thickness: 20 μm) was formed on one surface of the paper substrate to obtain an outer layer material. The coating layer was formed using medium density polyethylene (density: 0.930 g / cm 3 ) was formed on one side of a paper substrate by extrusion lamination. The inner layer material and the outer layer material were then arranged so that the vapor-deposited layer of the inner layer material faced the paper substrate of the outer layer material, and the density was reduced to 0.918 g / cm by extrusion lamination. 3 The film was laminated with an adhesive resin layer (thickness: 15 μm) made of low-density polyethylene to obtain a packaging film. The packaging film thus obtained was used to prepare a 250 ml brick-shaped paper container for liquid storage. The brick-shaped liquid paper containers were then filled with water. The rigidity was evaluated based on the degree of deformation of the paper containers and whether or not they could be filled, according to the following criteria. The results are shown in Tables 1 to 5. (standard) ◎: The paper container does not deform and can be filled without any problems 〇: The paper container is slightly deformed, but it can still be filled. ×: The paper container is deformed and cannot be filled.

[0148] (3) Piercing resistance In order to evaluate the puncture resistance of the gas barrier laminates obtained in the Examples and Comparative Examples, evaluation samples were prepared as follows. That is, a gas barrier laminate having a density of 0.918 g / cm was extrusion laminated onto the vapor deposition layer of the gas barrier laminate. 3 A sealant layer (thickness: 20 μm) made of low-density polyethylene was formed on the surface of the resin to prepare an evaluation sample. The evaluation sample was then fixed in place and pierced from the base layer side with a plastic straw (angle of the tip surface relative to the longitudinal direction: 45°). The piercing resistance was evaluated based on the feel determined by the following criteria. The results are shown in Tables 1 to 5. (standard) ◎: The straw makes a hole with a light touch and the tip of the straw does not get crushed. 〇: You need to push the straw in hard to make a hole, but the tip of the straw doesn't get crushed. ×: The straw needs to be pushed hard to make a hole and the tip of the straw gets crushed.

[0149] (4) Adhesion In order to evaluate the adhesion of the gas barrier laminates obtained in the Examples and Comparative Examples to other films, evaluation samples were prepared as follows. A dry laminating adhesive (urethane adhesive) was applied to the vapor deposition layer of the gas barrier laminate and dried to form an adhesive layer. A linear low-density polyethylene (LLDPE) film (thickness: 60 μm) was then attached to the vapor deposition layer of the gas barrier laminate via this adhesive layer, and the resulting laminate was thoroughly aged to obtain a laminate sheet. Then, a 15 mm wide strip extending in the MD direction was cut out from this laminate sheet, and this strip was used as an evaluation sample. For this evaluation sample, the gas barrier laminate and the sealant layer were peeled off by hand along the longitudinal direction, and the adhesion of the gas barrier laminate was evaluated using the following criteria depending on the degree of peeling. The results are shown in Tables 1 to 5. (standard) ⊚: The gas barrier laminate stretches and the sealant layer does not peel off from the gas barrier laminate. Good: The gas barrier laminate and the sealant layer are not easily peeled off. ×: The gas barrier laminate and the sealant layer easily peeled off. [Table 1] [Table 2] [Table 3] [Table 4] [Table 5]

[0150] From the results shown in Tables 1 to 5, the gas barrier laminates of Examples 1 to 9 were rated as "◎" or "◯" for transportability, rigidity, puncture resistance, and adhesion, whereas the gas barrier laminates of Comparative Examples 1 to 21 were rated as "×" for at least one of transportability, rigidity, puncture resistance, and adhesion. From the above, it was confirmed that the gas barrier laminate of the present disclosure has excellent transportability, rigidity, and puncture resistance, as well as excellent adhesion to other films.

[0151] From the above, it was confirmed that the gas barrier laminate of the present disclosure can improve the gas barrier properties even after abuse. [Explanation of symbols]

[0152] 10...base material layer, 20...anchor coat layer, 30...barrier layer, 31...vapor deposition layer, 32...overcoat layer, 100...gas barrier laminate, 200...packaging film, 210...sealant layer, 220...outer layer material, 300...packaging container, 400...packaged product, C...contents

Claims

1. A gas barrier laminate comprising a substrate layer and a barrier layer, the base layer is a biaxially stretched film containing polyethylene, the base layer includes a first layer and a second layer in this order from the side farthest from the barrier layer, the probe drop temperature of the first layer is 140°C or more and 160°C or less; the probe drop temperature of the second layer is 180°C or more and 210°C or less; The thickness of the first layer is 2 μm or more and 10 μm or less, The thickness of the second layer is 15 μm or more and 25 μm or less, The gas barrier laminate, wherein the thickness of the base layer is 20 μm or more and 30 μm or less.

2. 2. The gas barrier laminate according to claim 1, wherein the ratio of the thickness of the second layer to the thickness of the first layer is greater than 4 and not greater than 12.

3. The gas barrier laminate according to claim 1 , wherein the base layer further comprises a third layer between the second layer and the barrier layer.

4. The gas barrier laminate according to claim 1 , wherein the barrier layer further comprises a vapor-deposited layer of an inorganic oxide.

5. The gas barrier laminate according to claim 4 , wherein the barrier layer further comprises an overcoat layer on the side of the vapor deposition layer opposite the substrate layer, the overcoat layer being a gas barrier coating layer.

6. the overcoat layer is obtained using a composition for forming an overcoat layer, the composition including a silicon compound and a water-soluble polymer; 6. The gas barrier laminate according to claim 5, wherein the silicon compound comprises at least one of a silicon alkoxide, a hydrolyzate thereof, and a polycondensate thereof.

7. The gas barrier laminate according to claim 4 , further comprising an anchor coat layer between the barrier layer and the substrate layer.

8. The gas barrier laminate according to claim 7 , wherein the anchor coat layer comprises an acrylic urethane resin.

9. A packaging film comprising the gas barrier laminate according to any one of claims 1 to 8 and a sealant layer.

10. The packaging film according to claim 9 , further comprising an outer layer material, which is provided on the opposite side of the gas barrier laminate from the sealant layer and which contains a paper substrate.

11. The packaging film according to claim 10, wherein the outer layer material is bonded to the gas barrier laminate via an adhesive resin layer by extrusion lamination.

12. A packaging container comprising the packaging film according to claim 10.

13. A packaging product comprising the packaging container according to claim 12 and a content filled in the packaging container.

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