gas barrier film

Abstract

To provide a gas barrier film that has a low environmental impact and sufficient gas barrier performance as a packaging material. [Solution] The solution comprises a substrate mainly composed of polypropylene, a pre-treatment layer formed on the first surface of the substrate, a gas barrier layer formed on the pre-treatment layer, and a coating layer formed on the gas barrier layer, wherein the substrate has at least two layers, a base layer and a surface layer, and the power spectral density obtained from atomic force microscopy measurements in a 1 μm × 1 μm area on the first surface of the substrate is 0.0003 nm at a wavelength of 1 nm. 2 Below / Hz, 0.0032nm at a wavelength of 10nm 2 Below / Hz, and 0.1059nm at a wavelength of 100nm. 2 A gas barrier film characterized by satisfying a frequency of less than or equal to / Hz.

Description

[Technical Field]

[0001] This invention relates to a gas barrier film suitable for packaging food, pharmaceuticals, precision electronic components, and the like. [Background technology]

[0002] In packaging materials used for food and pharmaceuticals, gas barrier properties are sometimes required to prevent deterioration of the contents and maintain their functions and properties. These properties include blocking oxygen, water vapor, and other gases that can alter the contents and permeate the packaging material. Gas barrier films, which use metal foil such as aluminum as a gas barrier layer and are less affected by temperature and humidity, are known as packaging materials with gas barrier properties.

[0003] Another type of gas barrier film is one in which an inorganic oxide film, such as silicon dioxide or aluminum oxide, is formed on a base film made of polymer material by vacuum deposition or sputtering (see, for example, Patent Document 1). These gas barrier films are transparent and have gas barrier properties against oxygen, water vapor, and other gases. Polyethylene terephthalate (PET) is commonly used as the base film. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 60-49934 [Patent Document 2] Japanese Patent Publication No. 2008-23898 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Until now, polyethylene terephthalate (PET) has commonly been used as the base film for gas barrier films. However, in recent years, there has been a growing demand for gas barrier films using polypropylene (PP) or polyethylene (PE) base films in order to reduce the environmental burden. Patent Document 1 also describes the use of PP base films. However, the inventor's research has revealed that a gas barrier film in which aluminum oxide (AlOx) is simply formed as a barrier layer on a PP base film does not have sufficient gas barrier performance.

[0006] Based on the above problems, the present invention aims to provide a gas barrier film that has a low environmental impact and sufficient gas barrier performance as a packaging material. [Means for solving the problem]

[0007] A first aspect of the present invention is a gas barrier film comprising a substrate mainly composed of polypropylene, a pre-treatment layer formed on the first surface of the substrate, a gas barrier layer formed on the pre-treatment layer, and a coating layer formed on the gas barrier layer, wherein the substrate has at least two layers: a base layer and a surface layer. The power spectral density obtained from the substrate surface of this gas barrier film is 0.0003 nm at a wavelength of 1 nm. 2 Below / Hz, 0.0032nm at a wavelength of 10nm 2 Below / Hz, and 0.1059nm at a wavelength of 100nm. 2 This gas barrier film is characterized by satisfying the requirement of being less than or equal to / Hz. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a gas barrier film that has a low environmental impact and sufficient gas barrier performance as a packaging material. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view of a gas barrier film according to one embodiment of the present invention. [Figure 2] It is a graph showing the power spectral density in Example 1 and Comparative Example 1.

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1.

[0011] FIG. 1 is a schematic cross-sectional view of the gas barrier film 1 according to this embodiment. The gas barrier film 1 includes a base material 10, a pretreatment layer 20, a vapor deposition layer 30, a coating layer 40, an adhesive layer 50, and a sealant layer 60.

[0012] The base material 10 used in the present invention has two or more resin layers mainly composed of polypropylene. The base material 10 of this embodiment has two resin layers, a base layer and a surface layer laminated on the base layer.

[0013] The base material 10 having two or more resin layers can be formed, for example, by coextrusion. The total thickness of the base material 10, which is the sum of the base layer and the surface layer, can be, for example, 3 to 200 μm, and preferably 15 to 60 μm.

[0014] As the resin serving as the raw material for each layer of the base material 10, polypropylene is used as the main component from the viewpoints of easy availability, water vapor barrier property, and suppression of addition to the environment. The polypropylene may be any of a homopolymer, a random copolymer, a block copolymer, and a terpolymer. The homopolymer is polypropylene composed only of propylene monomers. The random copolymer is polypropylene in which propylene, which is the main monomer, and a comonomer of a different type from propylene are randomly copolymerized to form a homogeneous phase. The block copolymer is polypropylene in which propylene, which is the main monomer, and the above comonomer are block copolymerized or rubber-polymerized to form a heterogeneous phase. The terpolymer is polypropylene in which propylene, which is the main monomer, and two types of comonomers different from propylene are copolymerized. Any one of these polyolefin resins may be used alone, or two or more of them may be blended and used. As the raw material for the base layer 11, any of a homopolymer, a random copolymer, and a block copolymer is preferable. As the raw material for the surface layer 12, any of a random copolymer, a block copolymer, and a terpolymer is preferable.

[0015] Each layer formed on the base material 10 may be formed on both surfaces of the base material 10. Various well-known additives and stabilizers, such as antistatic agents, ultraviolet ray inhibitors, antioxidants, plasticizers, lubricants, etc., may be present on one or both surfaces of the base material 10.

[0016] The power spectrum of the base material surface can be obtained by an atomic force microscope (AFM). By processing the cross-sectional profile of the surface roughness obtained from the AFM by Fourier transform and performing frequency analysis, the power spectrum at each wavelength can be calculated. The inventors have found that good gas barrier properties can be obtained when the power spectrum density of the surface of the base material 10 is 0.001 nm 2 / Hz or less at a wavelength of 1 nm, 0.020 nm 2 / Hz or less at a wavelength of 10 nm, and 0.200 nm 2 / Hz or less at a wavelength of 100 nm.

[0017] The gas barrier film 1 of this embodiment has a gas barrier layer (deposited layer 30) that exhibits good gas barrier performance.

[0018] Before forming the vapor-deposited layer 30, a pre-treatment layer 20 is formed on the substrate 10. The pre-treatment layer 20 may be a coating layer made of a thermoplastic resin, thermosetting resin, UV-curing resin, or a plasma treatment layer. From a productivity standpoint, plasma treatment that can be performed in-line is preferred. The plasma treatment method is not particularly limited and may include glow discharge, and magnets may be used to increase the plasma density. The gas used during plasma treatment can be selected from oxygen, nitrogen, argon, or one or more of these.

[0019] The vapor-deposited layer 30 is mainly composed of aluminum oxide and is a layer that exhibits barrier properties against certain gases such as oxygen and water vapor. The vapor-deposited layer 30 may be transparent or opaque.

[0020] The thickness of the vapor-deposited layer 30 varies depending on the type, composition, and deposition method of the inorganic compound used, but can generally be set appropriately within the range of 3 to 300 nm. If the thickness of the vapor-deposited layer 30 is less than 3 nm, a uniform film may not be obtained, or the film thickness may be insufficient, potentially resulting in inadequate performance as a gas barrier layer. If the thickness of the vapor-deposited layer 30 exceeds 300 nm, the vapor-deposited layer 30 becomes hard, and external factors such as bending and stretching after deposition may cause cracks in the vapor-deposited layer 30, potentially leading to a loss of barrier properties. Therefore, the thickness of the vapor-deposited layer 30 is preferably within the range of 6 to 150 nm.

[0021] There are no restrictions on the method of forming the vapor-deposited layer 30; for example, vacuum deposition, sputtering, ion plating, and plasma vapor deposition (CVD) can be used.

[0022] The coating layer 40 further enhances the barrier properties of the vapor-deposited layer 30. The coating layer 40 is formed using a coating agent mainly composed of an aqueous solution or water / alcohol mixture containing a water-soluble polymer and one or more metal alkoxides or their hydrolysates. For example, the coating agent is prepared by dissolving a water-soluble polymer in an aqueous solvent (water or a water / alcohol mixture) and mixing it with a metal alkoxide, either directly or after being treated by hydrolysis. After applying this coating agent onto the vapor-deposited layer 30, the coating layer 40 can be formed by drying.

[0023] The components of the coating agent for forming the coating layer 40 will be described in more detail below. Examples of water-soluble polymers used in the coating agent include polyvinyl alcohol (PVA), polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. In particular, PVA is preferred because it provides excellent gas barrier properties. PVA is generally obtained by saponifying polyvinyl acetate. As PVA, either so-called partially saponified PVA, in which several tens of percent of acetate groups remain, or fully saponified PVA, in which only a few percent of acetate groups remain, can be used. PVA intermediate between the two may also be used.

[0024] Metal alkoxides used as coating agents are compounds that can be represented by the general formula M(OR)n (M: metal such as Si or Al, R: alkyl group such as CH3 or C2H5). Specifically, examples include tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum Al[OCH(CH3)2]3. Examples of silane coupling agents include those having an epoxy group such as 3-glycidoxypropyltrimethoxysilane, those having an amino group such as 3-aminopropyltrimethoxysilane, those having a mercapto group such as 3-mercaptopropyltrimethoxysilane, those having an isocyanate group such as 3-isocyanatetopropyltriethoxysilane, and tris-(3-trimethoxysilylpropyl)isocyanurate.

[0025] There are no restrictions on the method of applying the coating agent; conventionally known methods such as dipping, roll coating, screen printing, spraying, and gravure printing can be appropriately selected.

[0026] Another preferred example of the coating layer 40 is a film containing a polyvalent metal salt of carboxylic acid, which is a reaction product of the carboxyl group of a polycarboxylic acid polymer (A) and a polyvalent metal compound (B) (polycarboxylic acid polyvalent metal salt film). In this case, the polycarboxylic acid polyvalent metal salt film may be formed by applying and heating a coating agent which is a mixture of the polycarboxylic acid polymer (A) and the polyvalent metal compound (B), or it may be a polycarboxylic acid polyvalent metal salt film formed by applying and drying a coating agent mainly composed of the polycarboxylic acid polymer (A) to form film A, then applying and drying a coating agent mainly composed of the polyvalent metal compound (B) to form film B, and then crosslinking the A / B layers.

[0027] [Polycarboxylic acid polymer (A)] Polycarboxylic acid polymers are polymers that have two or more carboxyl groups in their molecule. Examples of polycarboxylic acid polymers include (co)polymers of ethylenically unsaturated carboxylic acids; copolymers of ethylenically unsaturated carboxylic acids with other ethylenically unsaturated monomers; and acidic polysaccharides that have carboxyl groups in their molecule, such as alginic acid, carboxymethylcellulose, and pectin.

[0028] Among the above, from the viewpoint of the gas barrier properties of the resulting gas barrier film, polymers containing structural units derived from at least one polymerizable monomer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid, and crotonic acid are preferred, and polymers containing structural units derived from at least one polymerizable monomer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, and itaconic acid are particularly preferred.

[0029] When a coating agent mainly composed of a polycarboxylic acid polymer (A) is applied and dried to form film A, and then film B is formed, some of the carboxyl groups of the polycarboxylic acid polymer may be neutralized in advance with a basic compound. By neutralizing some of the carboxyl groups of the polycarboxylic acid polymer in advance, the water resistance and heat resistance of film A can be further improved.

[0030] As the basic compound, at least one basic compound selected from the group consisting of polyvalent metal compounds, monovalent metal compounds, and ammonia is preferred. As the polyvalent metal compound, the compounds exemplified in the description of polyvalent metal compound (B) described later can be used. Examples of monovalent metal compounds include sodium hydroxide and potassium hydroxide.

[0031] [Polyvalent metal compounds (B)] The polyvalent metal compound is not particularly limited as long as it is a compound that reacts with the carboxyl group of the polycarboxylic acid polymer to form a polyvalent metal salt of the polycarboxylic acid, and examples include zinc oxide particles, magnesium oxide particles, magnesium methoxide, copper oxide, and calcium carbonate. These may be used individually or in combination. Zinc oxide is preferred from the viewpoint of oxygen barrier properties.

[0032] Examples of solvents used in coating agents mainly composed of polyvalent metal compounds (B) include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. These solvents may be used individually or in combination of two or more.

[0033] Among these, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred from the viewpoint of coating properties. Furthermore, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferred from the viewpoint of manufacturability.

[0034] When forming a polyvalent metal salt film of polycarboxylic acid by applying and drying a coating agent which is a mixture of a polycarboxylic acid polymer (A) and a polyvalent metal compound (B), the polycarboxylic acid polymer (A) and the polyvalent metal compound (B) can be mixed with water or alcohols as a solvent, along with a resin or dispersant that can dissolve or disperse in the solvent, and additives as needed, to form a coating agent which can then be applied and dried using a known coating method to form a polyvalent metal salt film of polycarboxylic acid. Examples of coating methods include the casting method, dipping method, roll coating method, gravure coating method, screen printing method, reverse coating method, spray coating method, kit coating method, die coating method, metering bar coating method, chamber doctor combined coating method, and curtain coating method.

[0035] The thickness of the coating layer 40 can be appropriately determined based on the composition of the coating agent and coating conditions, and there are no particular restrictions. However, if the film thickness of the coating layer 40 after drying is 0.01 μm or less, a uniform coating film may not be formed, and sufficient gas barrier properties may not be obtained. If the film thickness after drying exceeds 50 μm, cracks are more likely to occur in the coating layer 40. Therefore, a suitable thickness for the coating layer 40 is, for example, in the range of 0.01 to 50 μm. The optimal thickness for the coating layer 40 is, for example, in the range of 0.1 to 10 μm.

[0036] The sealant layer 60 is a layer that is joined by heat fusion when forming a bag-shaped package or the like using the gas barrier film 1. Examples of the material of the sealant layer 60 include resin materials such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and their metal crosslinked products. The thickness of the sealant layer 60 is determined according to the purpose, and for example, it is in the range of 15 to 200 μm.

[0037] The adhesive layer 50 joins the sealant layer 60 and the coating layer 40. By using the adhesive layer 50, the resin film that becomes the sealant layer 60 and the base material 10 on which the vapor deposition layer 30 and the coating layer 40 are formed can be laminated by dry lamination. An example of the material of the adhesive layer 50 is a two-component curable polyurethane-based adhesive, and a printing layer and a sealant layer 60 can be laminated on the coating layer 40 to obtain a packaging material. Another film may be interposed between the coating layer 40 and the sealant layer 60.

Example

[0038] The gas barrier film of this embodiment will be further described using examples and comparative examples. The present invention is not limited by the specific contents of the examples and comparative examples.

[0039] (Example 1) As the base material 10, a biaxially stretched polypropylene film with a thickness of 20 μm was used, and as the pretreatment layer 20, a plasma treatment layer with O2 gas was formed at a treatment intensity of 100 W·sec / m 2 The calculation of the treatment intensity is as follows. Power density [W / m 2 = Input power [W] / Cathode area [m 2 Treatment time [sec] = Electrode MD width [m] / Treatment speed [m / sec] Treatment intensity = Power density [W / m 2 · Treatment time [sec] ​

[0040] After plasma treatment under the above conditions, a 10 nm thick deposited layer 30 made of aluminum oxide was formed by electron beam deposition in a continuous vacuum chamber.

[0041] On the vapor-deposited layer 30, 10.4 g of tetraethoxysilane was mixed with 89.6 g of hydrochloric acid (0.1 N), stirred for 30 minutes to hydrolyze it, and a hydrolysis solution with a solid content of 3 wt% (in terms of SiO2) was applied by gravure coating and dried to form a coating layer 40 with a thickness of 0.4 μm.

[0042] Finally, an unstretched polypropylene film (30 μm thick) was laminated onto the coating layer 40 by dry lamination using a two-component curing polyurethane adhesive to obtain the gas barrier film of Example 1.

[0043] (Example 2) As the pretreatment layer 20, a plasma treatment layer using O2 gas was performed at 750 W·sec / m². 2 The gas barrier film of Example 2 was prepared in the same manner as in Example 1, except that it was formed with a specific treatment strength.

[0044] (Example 3) As the pretreatment layer 20, a plasma treatment layer with Ar gas was performed at 100 W·sec / m². 2 Except for the fact that it was formed with a specific treatment strength, the gas barrier film of Example 3 was prepared in the same manner as in Example 1.

[0045] (Example 4) As the pretreatment layer 20, a plasma treatment layer with Ar gas was performed at 750 W·sec / m². 2 Except for the fact that it was formed with a specific treatment strength, the gas barrier film of Example 4 was prepared in the same manner as in Example 1.

[0046] (Comparative Example 1) A gas barrier film of Comparative Example 1 was prepared in the same manner as in Example 1, except that the pretreatment layer 20 was not formed.

[0047] The evaluation items and measurement methods for each example and comparative example are shown below.

[0048] (Power spectral analysis of the substrate surface) Power spectral analysis of the substrate surface was performed using an atomic force microscope (AFM5400L) manufactured by Hitachi High-Tech Science Corporation, and cross-sectional profile data (in nm) was acquired in a 1 μm × 1 μm area. The obtained cross-sectional waveform was divided into each frequency component using Fourier transform, and the power spectral intensity at the frequencies included in each range was integrated for each unit frequency width. Then, the obtained power spectral intensity was divided by the number of data points to calculate the power spectral density, which is the power spectrum per unit frequency. The formula for calculating the power spectral density is shown below.

[0049] The waveform of the cross-sectional profile is irregular and is a superposition of waves of various frequencies, and can therefore be expressed by the following Fourier integral equation (1). The Fourier component X(f) is the wave e of frequency f. i2πft This represents the amplitude (in nm).

number

[0050] The obtained Fourier components represent the magnitude and phase of the complex number components of each frequency component. To express them as power values ​​per unit frequency width (1 Hz width) without depending on the frequency resolution Δf of the Fourier transform, the Fourier components are converted to energy (power) for comparison. The frequency resolution Δf is expressed by equation (2) below. Δf = 1 / T = f S / N···(2)

[0051] To increase the frequency resolution (reduce Δf), the sampling frequency f S This can be done by either lowering the value or increasing the sampling point N.

[0052] The complex number Z obtained from the Fourier transform can be expressed by the following equation (3), where a is the real component, bi is the imaginary component, and A is the real number. Z=a+bi=Ae iθ ...(3)

[0053] Therefore, the power spectrum can be represented by the absolute value |Z| of a complex number. Power spectrum A=|Z|=√(a 2 +b 2 ) ···(4)

[0054] Then, to convert this power spectrum to a value per unit frequency, the power spectrum was divided by the number of data points to obtain the power spectral density, which is the power spectrum per unit frequency.

[0055] (Evaluation of adhesion of the vapor-deposited layer immediately after manufacturing) For each example of gas barrier film, test specimens were cut in accordance with JIS Z1707, and the peel strength of the vapor-deposited layer 30 was measured using an Orientec Co., Ltd. Tensilon universal tester RTC-1250 as an indicator of adhesion. Two types of measurements were performed: T-shaped peel and 180° peel, both under normal conditions (Dry) and with the measurement site wet.

[0056] (Evaluation of gas barrier layer adhesion after hot water treatment) Two gas barrier films for each example were stacked with the sealant layer 60 facing each other, and the three sides were joined by heat fusion to create pouches (packaging containers) for each example. After filling each pouch with water as the contents, the open side was sealed by heat fusion. Subsequently, a hot water treatment was performed, which involved boiling (90°C for 30 minutes).

[0057] After hot water treatment, test specimens were cut from the parts of each pouch that had been in contact with the contents, in accordance with JIS Z1707. The peel strength of the vapor-deposited layer 30 was measured using an Orientec Tensilon universal tester RTC-1250 as an indicator of adhesion. Two types of measurements were performed: T-shaped peeling and 180° peeling, both under normal conditions (Dry) and with the measurement site wet.

[0058] (Evaluation of gas barrier performance immediately after manufacturing and after hot water treatment) After preparing each pouch using the above procedure, immediately after manufacturing and after hot water treatment, the pouch was opened and the oxygen permeability (OTR) of the gas barrier film was measured (unit: cc / m²). 2 • day·atm, measurement conditions: 30℃-70%RH), and water vapor transmission rate (WVTR) (unit: g / m³) 2 The measurement conditions (40°C-90%RH) were evaluated for each day.

[0059] The results are shown in Table 1.

[0060] [Table 1]

[0061] The gas barrier films according to Examples 1-4 have a power spectral density of 0.002 nm at a wavelength of 1 nm obtained from the substrate surface. 2 Below / Hz, 0.020nm at a wavelength of 10nm 2 / Hz or less, 0.300nm at a wavelength of 100nm 2 Because the frequency was below / Hz, a dense barrier layer was formed, resulting in excellent water vapor barrier properties after the coating layer was formed.

[0062] The gas barrier film according to Comparative Example 1 has a power spectral density of 0.002 nm at a wavelength of 1 nm obtained from the substrate surface. 2 Hz or higher, 0.020 nm at a wavelength of 10 nm 2 / Hz or higher, 0.300nm at a wavelength of 100nm 2 Because the frequency was above / Hz, the water vapor barrier performance after the formation of the coating layer was inferior compared to Examples 1-4.

[0063] Figure 2 shows a comparison of the power spectral density in Example 1 and Comparative Example 1. [Industrial applicability]

[0064] This invention can be used in gas barrier films for packaging and the like. [Explanation of Symbols]

[0065] 1. Gas barrier film 10 Base material 20 Pre-treatment layer 30 Deposited layer 40 Covering layer 50 adhesive layer 60 sealant layer

Claims

1. The device comprises a base material mainly composed of polypropylene, a pre-treatment layer formed on the first surface of the base material, a gas barrier layer formed on the pre-treatment layer, and a coating layer formed on the gas barrier layer. The substrate has at least two layers: a base layer and a surface layer. The power spectral density obtained from atomic force microscopy measurements in a 1 μm × 1 μm area on the first surface of the substrate is 0.0003 nm at a wavelength of 1 nm. ２ / Hz or less, 0.0032 nm at a wavelength of 10 nm ２ Below / Hz, and 0.1059 nm at a wavelength of 100 nm. ２ A gas barrier film characterized by satisfying a frequency of / Hz or less.

2. The base layer consists of one or more of polypropylene homopolymers, random copolymers, and block copolymers. The gas barrier film according to claim 1, wherein the surface layer is made of one or more of a random copolymer, block copolymer, or terpolymer of polypropylene.

3. The gas barrier film according to claim 1 or 2, wherein the gas barrier layer is mainly composed of aluminum, aluminum oxide, silicon oxide, or silicon oxide containing carbon, and has an average film thickness of 3 nm or more and 300 nm or less.

4. The gas barrier film according to any one of claims 1 to 3, wherein the coating layer contains one or more alkoxides or their hydrolysates, and one of a water-soluble polymer, a polyvalent metal compound, or a polyvalent metal salt of a carboxylic acid.

5. The water vapor permeability after the formation of the coating layer is 0.7 g / m². ２ - Below 1 day and with an oxygen permeability of 0.9 cc / m³ ２ A gas barrier film according to any one of claims 1 to 4, wherein the temperature is less than or equal to day·atm.

6. A gas barrier film according to any one of claims 1 to 5, further comprising a heat-sealable sealant layer, wherein the sealant layer is bonded to the coating layer by an adhesive layer.

7. The gas barrier film according to any one of claims 1 to 6, wherein the peel strength between the substrate and the gas barrier layer or sealant layer is 1.0 N / 15 mm or more.

8. After hot water treatment at 95°C for 30 minutes, Oxygen permeability of 5.0 cc / m²·day·atm or less, and water vapor permeability of 2.0 g / m ２ - less than or equal to day, The gas barrier film according to any one of claims 1 to 7, wherein the peel strength between the substrate and the gas barrier layer or sealant layer is 1.0 N / 15 mm or more.

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