Method for manufacturing a gas barrier film, gas barrier film, packaging film, and packaging material

Abstract

Disclosed is a method for producing a gas barrier film, the method including: a step for forming an inorganic oxide layer on a base material layer; a step for applying an active energy ray-curable resin composition onto the inorganic oxide layer so as to form a coating film; and a step for irradiating the coating film with an active energy ray so as to cure the coating film, thereby forming an overcoat layer. The active energy ray-curable resin composition contains an acrylic compound that satisfies formula (1) wherein NA is the number of acryloyl groups contained in each molecule and NB is the number of hydroxyl groups contained in each molecule.　Formula (1): NA × 2 + NB × 3 ≥ 5 (In the formula, NA ≥ 1 and NB ≥ 0.)

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing a gas barrier film, a gas barrier film manufactured by said manufacturing method, a packaging film comprising said gas barrier film, and a packaging material made from said packaging film. [Background technology]

[0002] Packaging materials used for food, pharmaceuticals, electronic components, machine parts, etc., require gas barrier properties to prevent the intrusion of gases (water vapor, oxygen, etc.) that alter the contents, in order to suppress deterioration and spoilage of the contents and maintain their function and quality. For this reason, film materials with gas barrier properties (gas barrier films) are used for these packaging materials.

[0003] As a packaging film equipped with a gas barrier film, for example, Patent Document 1 proposes a laminated material manufactured by preparing a polyurethane resin composition by mixing a polyurethane resin, nitrocellulose, a silane coupling agent, and a filler with a solvent and diluent, on the other hand, providing a thin film of inorganic oxide mainly consisting of a silicon oxide vapor deposition film by plasma chemical vapor deposition on one side of a flexible plastic substrate, then using the above polyurethane resin composition and coating it onto the surface of the thin film of inorganic oxide provided on one side of the flexible plastic substrate to form a coating thin film of the polyurethane resin composition, and then coating the surface of the coating thin film of the polyurethane resin composition with an adhesive made of a two-component curable polyurethane resin that is formed by a curing reaction between a polyester polyol or polyether polyol and an isocyanate, and then laminating at least a heat-sealable resin layer via the adhesive layer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2000-167973 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Generally, gas barrier films are manufactured by providing a gas barrier layer made of a material having gas barrier properties on the surface of a resin substrate. For example, in the above-mentioned Patent Document 1, the coating thin film made of a polyurethane resin composition corresponds to the gas barrier layer. The coating thin film is formed by applying the polyurethane resin composition to the target by a wet coating method such as the roll coating method, and then drying it with hot air to remove the solvent.

[0006] However, the heat generated during hot air drying can deform the base film, potentially causing cracks in the gas barrier layer and degrading its gas barrier properties (especially oxygen barrier properties). In recent years, from the perspective of improving recyclability, there has been a trend to design packaging materials using a single polyolefin material, and polyolefin resin films such as OPP (oriented polypropylene) and PE (polyethylene) are being adopted as base films. However, such films are more susceptible to the effects of the heat mentioned above, and the degradation of their gas barrier properties is a greater concern.

[0007] This disclosure is made in view of the above circumstances and aims to provide a method for manufacturing a gas barrier film that can exhibit excellent gas barrier properties regardless of the heat resistance of the base film. This disclosure also aims to provide a gas barrier film manufactured by the said manufacturing method, a packaging film comprising the gas barrier film, and a packaging material made from the said packaging film. [Means for solving the problem]

[0008] In order to solve the above problems, the inventors have found that it is important to form a gas barrier layer by curing a resin composition containing a specific acrylic compound with active energy rays, and have completed the manufacturing method of the present disclosure. That is, one aspect of the present disclosure provides the following inventions.

[0009] [1] A step of forming an inorganic oxide layer on a substrate layer; A step of applying an active energy ray-curable resin composition on the inorganic oxide layer to form a coating film; A step of irradiating the coating film with active energy rays to cure it and form an overcoat layer, comprising: When the number of acryloyl groups contained in one molecule of the active energy ray-curable resin composition is N A and the number of hydroxyl groups is N B a method for producing a gas barrier film, comprising an acrylic compound satisfying the following formula (1). N A ×2 + N B ×3 ≥ 5 ···(1) (In the formula, N A ≥ 1 and N B ≥ 0.) [2] A gas barrier film comprising a substrate layer, an inorganic oxide layer, and an overcoat layer in this order, wherein the overcoat layer is a cured product of an active energy ray-curable resin composition having a crosslinked structure, and when the number of acryloyl groups contained in one molecule of the active energy ray-curable resin composition is N A and the number of hydroxyl groups is N B a gas barrier film comprising an acrylic compound satisfying the following formula (1). NA × 2 + N B ×3 ≥ 5 ···(1) (In the formula, N A ≥ 1 and N B ≥ 0.) [3] The gas barrier film according to [2], wherein N B ≥ 1. [4] The gas barrier film according to [2] or [3], wherein N B ≥ 3. [5] The gas barrier film according to any one of [2] to [4], wherein the active energy ray curable resin composition further comprises a carboxyl group-containing acrylic compound having a value of less than 5 in formula (1). [6] The gas barrier film according to [5], wherein the molecular weight of the carboxyl group-containing acrylic compound is less than the molecular weight of the acrylic compound satisfying formula (1). [7] The gas barrier film according to [5] or [6], wherein the molecular weight of the carboxyl group-containing acrylic compound is 100 or more and 500 or less. [8] The gas barrier film according to any one of [2] to [7], wherein the base layer comprises a polyolefin resin. [9] A gas barrier film according to any one of [2] to [8], wherein the thickness of the overcoat layer is 0.15 to 2 μm. A packaging film comprising a gas barrier film according to any one of

[10] [2] to [9], and a heat-sealable layer provided on the overcoat layer of the gas barrier film.

[11] Packaging material made from the packaging film described in

[10] . [Effects of the Invention]

[0010] This disclosure provides a method for manufacturing a gas barrier film that can exhibit excellent gas barrier properties regardless of the heat resistance of the base film. Furthermore, this disclosure provides a gas barrier film manufactured by the manufacturing method, a packaging film equipped with the gas barrier film, and a packaging material made from the packaging film. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic cross-sectional view of a gas barrier film according to the first embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view of a gas barrier film according to a second embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] Embodiments of the present disclosure will be described below with reference to the drawings. The embodiments described below are more specific to any of the above aspects. The matters described below can be incorporated into each of the above aspects, individually or in combination.

[0013] Furthermore, the embodiments shown below illustrate configurations for realizing the technical concept of this disclosure, and the technical concept of this disclosure is not limited by the materials, shapes, and structures of the components described below. Various modifications can be made to the technical concept of this disclosure within the technical scope defined by the claims described in the claims.

[0014] In the drawings referenced below, the same parts are denoted by the same reference numeral. Furthermore, the drawings are schematic, and the relationships between dimensions in one direction and those in another, as well as the relationships between the dimensions of one component and those of another, may differ from those in reality.

[0015] In this disclosure, oxygen barrier properties, which are one aspect of gas barrier properties, are evaluated by oxygen permeability (OTR), and a smaller value indicates better oxygen barrier properties.

[0016] <Gas barrier film> A gas barrier film comprises a substrate layer, an inorganic oxide layer, and an overcoat layer in this order. The overcoat layer is a cured product of an active energy ray curable resin composition having a cross-linked structure. The number of acryloyl groups contained in one molecule of the active energy ray-curable resin composition is N A The number of hydroxyl groups is N B In this case, it contains an acrylic compound that satisfies the following formula (1). N A ×2+N B ×3≧5 ···(1) (In the formula, N A ≥ 1 and NB (≥0.)

[0017] First, the first embodiment will be described with reference to Figure 1. Figure 1 is a schematic cross-sectional view of a gas barrier film according to the first embodiment of the present disclosure. The gas barrier film 100 comprises a base layer 10, a sub-layer 30, an inorganic oxide layer 40, and an overcoat layer 20 in this order.

[0018] A base layer 30 is formed on the base layer 10. An inorganic oxide layer 40 is formed on the base layer 30. An overcoat layer 20 is formed on the inorganic oxide layer 40.

[0019] In the gas barrier film, as described in the second embodiment, the underlayer 30 may not be provided.

[0020] Next, a second embodiment will be described with reference to Figure 2. Figure 2 is a schematic cross-sectional view of a gas barrier film according to a second embodiment of the present disclosure. The gas barrier film 200 is the same as the gas barrier film 100 but without the underlayer 30, and comprises a base layer 10, an inorganic oxide layer 40, and an overcoat layer 20 in that order.

[0021] The gas barrier films according to the first and second embodiments will be described below.

[0022] [Base material layer] Examples of resins constituting the base layer 10 include olefin resins such as polyethylene, polypropylene, polymers of olefins having 2 to 10 carbon atoms, and propylene-ethylene copolymers; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as aliphatic polyamides such as nylon 6 and nylon 66, and aromatic polyamides such as polymetaxylylene adipamide; vinyl resins such as polystyrene, polyvinyl acetate, ethylene-vinyl acetate copolymers, polyvinyl alcohol, and ethylene-vinyl alcohol copolymers; acrylic resins such as polymethyl methacrylate and acrylic monomers such as polyacrylonitrile, either alone or as copolymers; cellophane; and engineering plastics such as polycarbonate and polyimide. These resins may be used individually or in combination of two or more.

[0023] By using polyolefin resin films (especially polypropylene films) among these resins, it is possible to obtain monomaterial packaging materials with excellent recyclability.

[0024] The base layer 10 may be a single-layer film made of a single resin, or a single-layer or laminated film using multiple resins. The base layer 10 may also be a laminate of the above-mentioned resins on another base material (metal, wood, paper, ceramics, etc.).

[0025] The film constituting the base layer 10 may be an unstretched film, or a stretched film such as uniaxially stretched or biaxially stretched. From the viewpoint of excellent water vapor barrier properties, stretched polypropylene (OPP) film is particularly preferred as the base layer 10. When the base layer 10 includes an OPP film, there may be one or two or more layers of OPP film.

[0026] OPP film may be made by processing at least one polymer selected from homopolymers, random copolymers, and block copolymers into a film. Homopolymer is polypropylene consisting only of propylene monomers. Random copolymer is polypropylene in which propylene, the main monomer, and a small amount of comonomers different from propylene are randomly copolymerized to form a homogeneous phase. Block copolymer is polypropylene in which propylene, the main monomer, and the above comonomers copolymerize in a block-like manner or polymerize in a rubber-like manner to form a heterogeneous phase.

[0027] The surface of the base layer 10 on which the underlayer 30 or inorganic oxide layer 40 is formed may be subjected to surface treatments such as chemical treatment, solvent treatment, corona treatment, low-temperature plasma treatment, or ozone treatment. This can improve the adhesion between the base layer and the underlayer or inorganic oxide layer.

[0028] The film constituting the base layer 10 may contain additives such as fillers, antiblocking agents, antistatic agents, plasticizers, lubricants, and antioxidants. These additives may be used individually or in combination of two or more.

[0029] There are no particular restrictions on the thickness of the base layer 10, and it can be appropriately determined depending on the price and application, while considering its suitability as a packaging material and its suitability for lamination of other coatings. In practical terms, the thickness of the base layer 10 is preferably 3 to 200 μm, more preferably 5 to 120 μm, even more preferably 6 to 100 μm, and particularly preferably 10 to 30 μm.

[0030] [Base layer] The base layer 30 contains an organic polymer. The content of the organic polymer in the base layer 30 may be, for example, 70% by mass or more, or 80% by mass or more. Examples of organic polymers include polyacrylic resin, polyester resin, polycarbonate resin, polyol resin, polyurethane resin, polyamide resin, polyolefin resin, polyimide resin, melamine resin, phenolic resin, etc. Considering the hot water resistance of the adhesion strength between the base layer 10 and the inorganic oxide layer 40 or the overcoat layer 20, it is preferable that the base layer 30 contains at least one of a polyacrylic resin, a polyol resin, a polyurethane resin, a polyamide resin, or a reaction product of these organic polymers.

[0031] The base layer 30 may contain a silane coupling agent, organic titanate, modified silicone oil, etc.

[0032] More preferably, the organic polymer used in the base layer 30 is an organic polymer having a urethane bond, which is produced by the reaction of polyols having two or more hydroxyl groups at the molecular ends or in the molecular chain with an isocyanate compound, or an organic polymer containing a reaction product of polyols having two or more hydroxyl groups at the molecular ends or in the molecular chain with an organic silane compound such as a silane coupling agent or its hydrolysate. Either one or both of these may be used.

[0033] Examples of the polyols mentioned above include at least one selected from acrylic polyols, polyvinyl acetals, polystyrene polyols, and polyurethane polyols. Acrylic polyols may be obtained by polymerizing acrylic acid derivative monomers, or by copolymerizing acrylic acid derivative monomers with other monomers. Examples of acrylic acid derivative monomers include ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate. Examples of monomers copolymerized with acrylic acid derivative monomers include styrene.

[0034] The isocyanate compound enhances the adhesion between the substrate layer 10 and the inorganic oxide layer 40 or the overcoat layer 20 through the urethane bond formed by its reaction with the polyol. In other words, the isocyanate compound functions as a crosslinking agent or curing agent. Examples of isocyanate compounds include monomers such as aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aromatic aliphatic xylene diisocyanate (XDI), aliphatic hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), a mixture of 1-methylcyclohexane-2,4-diisocyanate and 1-methylcyclohexane-2,6-diisocyanate (HTDI, hydrogenated TDI), and cyclohexylmethane diisocyanate (HMDI, hydrogenated MDI), polymers thereof, and derivatives thereof. The above-mentioned isocyanate compounds may be used individually or in combination of two or more.

[0035] Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-methacryloyloxypropylmethyldimethoxysilane. The organosilane compound may be a hydrolysate of these silane coupling agents. The organosilane compound may contain one of the above-mentioned silane coupling agents and their hydrolysates alone, or in combination of two or more.

[0036] The base layer 30 can be formed using a mixture obtained by blending the above-mentioned components in an organic solvent in any proportion. The mixture may contain, for example, curing accelerators such as tertiary amines, imidazole derivatives, metal salt compounds of carboxylic acids, quaternary ammonium salts, and quaternary phosphonium salts; antioxidants such as phenolic, sulfuric, and phosphite-based agents; leveling agents; flow regulators; catalysts; crosslinking reaction accelerators; fillers, etc.

[0037] There are no particular restrictions on the thickness of the underlayer 30; for example, it can be 0.005 to 5 μm. The thickness can be appropriately determined depending on the application or required properties. The thickness of the underlayer 30 is preferably 0.01 to 1 μm, and more preferably 0.01 to 0.5 μm. If the thickness of the underlayer 30 is 0.01 μm or more, sufficient adhesion strength between the base material layer 10 and the inorganic oxide layer 40 or overcoat layer 20 can be obtained, and gas barrier properties will also be good. If the thickness of the underlayer 30 is 1 μm or less, it becomes easier to form a uniform coated surface, and drying load and manufacturing costs can be suppressed.

[0038] As shown in Figure 2, if no underlayer is provided, the heating process applied to the base material layer can be reduced. However, providing an underlayer makes it easier to improve the smoothness of the base material layer surface, thus suppressing the decrease in gas barrier properties due to the deterioration of the film quality of the formed inorganic oxide layer.

[0039] [Inorganic oxide layer] Examples of inorganic oxides constituting the inorganic oxide layer 40 include aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, tin oxide, zinc oxide, and indium oxide. In particular, aluminum oxide or silicon oxide are preferred because they offer excellent productivity and superior oxygen barrier and water vapor barrier properties under high temperature and high humidity conditions. The inorganic oxide layer 40 may be formed from one type of inorganic oxide, or from two or more inorganic oxides selected as appropriate.

[0040] The thickness of the inorganic oxide layer 40 can be 1 to 200 nm. If the thickness is 1 nm or more, excellent oxygen barrier and water vapor barrier properties are easily obtained. If the thickness is 200 nm or less, manufacturing costs can be kept low, and cracks caused by external forces such as bending and pulling are less likely to occur, making it easier to suppress deterioration of gas barrier properties.

[0041] The inorganic oxide layer 40 can be formed by known film deposition methods such as vacuum deposition, sputtering, ion plating, or plasma vapor deposition (CVD).

[0042] [Overcoat layer (gas barrier coating / oxygen barrier coating)] The overcoat layer 20 is a cured coating film containing an acrylic compound (a compound having an acryloyl group). For example, it is an organic polymer film obtained by curing a coating film, which is made by applying a solvent-free coating solution containing monomers and oligomers of an acrylic compound, i.e., an active energy ray curable resin composition, by irradiation with active energy rays such as EB (electron beam) or UV (ultraviolet). As can be understood from its manufacturing method, the overcoat layer is a cured product of an active energy ray curable resin composition having a crosslinked structure.

[0043] The active energy ray-curable resin composition contains at least an acrylic compound monomer (or oligomer), and may further contain additives such as a methacrylic compound (a compound having a methacryloyl group), a photoradical generator, or a silane coupling agent. Note that curing can be achieved using EB even if the composition does not contain a photoradical generator. From a hygienic standpoint, the composition does not need to contain a photoradical generator.

[0044] Acrylic compounds are generally low-cost and are active energy ray curable compounds that exhibit superior EB curing speeds and UV curing speeds compared to methacrylic compounds. Active energy ray curable resin compositions may contain one or more acrylic compounds.

[0045] The active energy ray curable resin composition has a number of acryloyl groups in one molecule of N A The number of hydroxyl groups is N B In this case, it contains an acrylic compound that satisfies the following formula (1). N A ×2+N B ×3≧5 ···(1) (In the formula, N A ≥ 1 and N B (≥0.)

[0046] When the value of formula (1) is 5 or greater, the crosslinking density by acryloyl groups is improved compared to when it is less than 5, making it easier to form a denser film. This makes the film less permeable to oxygen molecules, and it is easier to exhibit better gas barrier properties. From this viewpoint, it is preferable that the value of formula (1) is 6 or greater, 8 or greater, or 10 or greater. On the other hand, the upper limit of the value of formula (1) can be, for example, 65, but from the viewpoint of suppressing the embrittlement of the film due to an overly dense internal structure and maintaining the ease of handling (flexibility) of the film, the upper limit of the value of formula (1) may be 30 or less, or 15 or less.

[0047] The number of acryloyl groups contained in one molecule of acrylic compound: N A It can take values ​​from 1 to 15. A A hardening reaction can be produced when N is 1 or greater. A Having N 15 or less makes it easier to maintain the flexibility of the coating. This makes it less likely for the coating to crack or peel off from the substrate layer, and makes it easier to ensure gas barrier properties. From this perspective, N A It may be up to 10, 2 to 6, or 3 to 6.

[0048] The number of hydroxyl groups contained in one molecule of acrylic compound: N B This can take values ​​from 0 to 20. Acrylic compounds do not necessarily need to contain hydroxyl groups, but including hydroxyl groups improves the balance of interactions within the film due to the hydroxyl groups, making it easier to improve gas barrier properties. N BHaving N below 20 makes it easier to maintain an appropriate viscosity for the acrylic compound. This results in good coating properties and makes it easier to form a homogeneous film. From this perspective, N B The value can be between 1 and 15, or between 3 and 10.

[0049] Examples of acrylic compounds satisfying the above formula (1) include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, 1-(acryloyloxy)-3-(methacryloyloxy)-2-propanol, glycerin diacrylate, 1,6-hexanediylbis(oxy)bis(2-hydroxy-3,1-propanediyl) bisacrylate, bisphenol A diglycidyl ether acrylic acid adduct, and glycerin. You can use 1,3-diglycerolate diacrylate, tris(2-hydroxyethyl)isocyanurate diacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, glycerin triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, EO-modified pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, EO-modified dipentaerythritol hexaacrylate, etc.

[0050] In addition, epoxy acrylates, urethane acrylates, polyester methacrylates, etc. that satisfy formula (1), other than those mentioned above, can be used.

[0051] N B is 1 or greater (N BExamples of acrylic compounds that satisfy ≥1 include glycerin diacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, 1-(acryloyloxy)-3-(methacryloyloxy)-2-propanol, 1,6-hexanediylbis(oxy)bis(2-hydroxy-3,1-propanediyl) bisacrylic acid, bisphenol A diglycidyl ether acrylic acid adduct, glycerin 1,3-diglycerolate diacrylate, tris(2-hydroxyethyl)isocyanurate diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, etc.

[0052] N B is 3 or more (N B As an acrylic compound satisfying the requirement ≥3), for example, glycerin 1,3-diglycerolate diacrylate can be used.

[0053] The gas barrier properties of organic polymers depend on their free volume and cohesive energy. Free volume refers to the gaps between polymer molecules; a smaller free volume results in higher gas barrier properties. To suppress the thermal motion of molecules, it is preferable to use resins with high glass transition temperatures and to increase their crosslinking density. Many acrylic resins have relatively low glass transition temperatures.

[0054] Cohesive energy is the energy related to the magnitude of the interaction between functional groups and polar groups with the permeate gas. For oxygen gas, chloro groups, fluoro groups, and hydroxyl groups are known to be excellent, with hydroxyl groups being particularly excellent. Therefore, in order to form an organic polymer film with superior gas barrier properties, it is preferable to use an acrylic compound having hydroxyl groups (hydroxyl group-containing acrylic compound) as described above.

[0055] The molecular weight of the acrylic compound is preferably 200 or more, and more preferably 300 or more. Generally, coatings formed from acrylic compounds tend to have poor gas barrier properties, especially oxygen barrier properties. However, by using an acrylic compound with a molecular weight of 200 or more, preferably 300 or more, the internal structure of the coating becomes stronger, and it is easier to exhibit excellent gas barrier properties. From this viewpoint, the molecular weight is preferably 350 or more. On the other hand, from the viewpoint of coating properties as a resin composition, the upper limit of the molecular weight can be 1900 or less, but from the viewpoint of coating properties, the molecular weight may be 1000 or less, 700 or less, or 500 or less. From the viewpoint of achieving both gas barrier properties and coating properties, the molecular weight is preferably 300 to 1900, 300 to 1000, 310 to 1000, 320 to 1000, 350 to 1000, 350 to 700, or 350 to 500.

[0056] Examples of acrylic compounds with a molecular weight of 300 or more include 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid, 1,6-hexanediylbis(oxy)bis(2-hydroxy-3,1-propanediyl) bisacrylic acid, bisphenol A diglycidyl ether acrylic acid adduct, glycerin 1,3-diglycerolate diacrylate, tris(2-hydroxyethyl)isocyanurate diacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, EO-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, EO-modified pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and EO-modified dipentaerythritol hexaacrylate.

[0057] From the viewpoint of gas barrier properties, acrylic compounds having an isocyanurate skeleton can be used. For example, acrylic compounds having an isocyanurate skeleton such as tris(2-hydroxyethyl)isocyanurate diacrylate and tris(2-hydroxyethyl)isocyanurate triacrylate are preferably used.

[0058] From the viewpoint of improving the coatability as a coating liquid, the active energy ray curable resin composition may further contain an acrylic compound that does not satisfy the above formula (1), that is, an acrylic compound whose value in formula (1) is less than 5 (4 or less). In other words, the active energy ray curable resin composition may contain acrylic compounds in which the value of formula (1) is 5 or more, and acrylic compounds in which the value of formula (1) is less than 5.

[0059] Examples of acrylic compounds whose value in formula (1) is less than 5 include phenoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxydipropylene glycol acrylate, butoxyethyl acrylate, butoxydiethylene glycol acrylate, butyl acrylate (butyl acrylate), isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, methoxyethylene glycol acrylate, and Toxydiethylene glycol acrylate, Methoxy PEG #200 acrylate, Methoxy PEG #400 acrylate, Methoxy PEG #600 acrylate, Methoxy PEG #1000 acrylate, Methoxy-polyethylene glycol acrylate, 2-Acryloyloxyethyl succinic acid, 2-Acryloyloxyethyl hexahydrophthalic acid, 2-Acryloyloxyethyl phthalic acid, Acrylic acid, ω-carboxypolycaprolactone monoacrylate, 2-Acryloyloxyethyl acid phosphate, Dimethylaminoacrylate Diethylaminoacrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate, phenoxyethyl acrylate, isobornyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, PEG#200 dimethacrylate, PEG#400 dimethacrylate, PEG#600 dimethacrylate, PEG#1000 dimethacrylate, polyethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, polytetramethylene glycol diacrylate, neopentyl glycol diacrylate, tricyclodecanedimethanol diacrylate, neopentyl glycol hydroxypivalate diacrylate, bisphenol A ethylene glycol diether diacrylate, bisphenol A polyethylene glycol diether diacrylate, etc. can be used.

[0060] From the viewpoint of forming a cross-linked structure inside the coating by EB curing and UV curing, it is preferable that at least one of the acrylic compounds used has two or more acryloyl groups.

[0061] In addition to the coatability of the active energy ray-curable resin composition, the active energy ray-curable resin composition may further contain a carboxyl group-containing acrylic compound as an acrylic compound having a value of less than 5 in formula (1), from the viewpoint of improving the adhesion between the cured overcoat layer and the inorganic oxide layer. Since polar carboxyl groups readily interact strongly with the inorganic oxide layer, the adhesion between the overcoat layer and the inorganic oxide layer tends to be further improved. In other words, the active energy ray curable resin composition may include an acrylic compound with a value of 5 or more in formula (1), and a carboxyl group-containing acrylic compound with a value of less than 5 in formula (1). However, the composition may also include an acrylic compound with a value of 5 or more in formula (1), as well as a carboxyl group-free acrylic compound with a value of less than 5 in formula (1) and a carboxyl group-containing acrylic compound with a value of less than 5 in formula (1).

[0062] As carboxyl group-containing acrylic compounds, for example, in addition to the above-mentioned 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, and 2-acryloyloxyethyl hexahydrophthalic acid, 2-carboxyethyl acrylate, ω-carboxypolycaprolactone monoacrylate, etc., can be used. Of these, 2-acryloyloxyethyl succinic acid or 2-acryloyloxyethyl hexahydrophthalic acid is preferred from the viewpoint of compatibility with acrylic compounds with a value of 5 or more in formula (1), gas barrier properties, etc., and 2-acryloyloxyethyl hexahydrophthalic acid is more preferred.

[0063] A carboxyl group-containing acrylic compound with a value of less than 5 in formula (1) may be large enough to fill the gaps between the crosslinked structures of an acrylic compound with a value of 5 or more in formula (1). This makes it easier to obtain a synergistic effect of improving the adhesion between the overcoat layer and the inorganic oxide layer, as well as the gas barrier properties. From this viewpoint, the molecular weight of the carboxyl group-containing acrylic compound is preferably less than the molecular weight of an acrylic compound with a value of 5 or more in formula (1), and specifically may be 500 or less, 400 or less, 300 or less, less than 300, or 200 or less. On the other hand, from the viewpoint of the curability of the composition, the molecular weight may be 100 or more. The molecular weight of the carboxyl group-containing acrylic compound is preferably 100 to 500, 100 to 400, 100 to 300, 100 to less than 300, 100 to 250, or 100 to 200.

[0064] The active energy ray-curable resin composition may further contain a methacrylic compound (a compound having a methacryloyl group) from the viewpoint of controlling reactivity and heat resistance. The methacrylic compound is also an excellent active energy ray-curable resin that can form organic polymer films at low cost.

[0065] Any methacrylic compound exhibiting excellent EB curability and UV curability can be used as the methacrylic compound.

[0066] For example, as methacrylic compounds, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, methoxydiethylene glycol methacrylate, methoxytriethylene glycol methacrylate, methoxydipropylene glycol methacrylate, butoxyethyl methacrylate, butoxydiethylene glycol methacrylate, butyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, methoxy PEG #200 methacrylate, methoxy PEG #400 methacrylate, methoxy PEG #600 methacrylate, methoxy PEG #1000 methacrylate, methoxy-polyethylene glycol methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl hexahydrate Lophthalic acid, 2-methacryloyloxyethyl phthalate, 2-methacryloyloxyethyl-2-hydroxyethyl phthalate, 2-methacryloyloxyethyl-2-hydroxyepropyl phthalate, methacrylic acid, 2-methacryloyloxyethyl acid phosphate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate, phenoxyethyl methacrylate, isovonyl methacrylate Diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, PEG#200 dimethacrylate, PEG#400 dimethacrylate, PEG#600 dimethacrylate, PEG#1000 dimethacrylate, polyethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-Nonanediol dimethacrylate, ditetramethylene glycol dimethacrylate, tritetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, tricyclodecane dimethanol dimethacrylate, neopentyl glycol hydroxypivalate dimethacrylate, bisphenol A ethylene glycol diether dimethacrylate, bisphenol A polyethylene glycol diether dimethacrylate, glycerin dimethacrylate, 1,6-hexanediylbis(oxy)bis(2-hydroxy-3,1-propanediyl) bismethacrylate, bisphenol A diglycidyl You can use trimethacrylate adducts, glycerin 1,3-diglycerolate dimethacrylate, tris(2-hydroxyethyl)isocyanurate dimethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, trimethylolpropane trimethacrylate, EO-modified trimethylolpropane trimethacrylate, glycerin trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, EO-modified pentaerythritol tetramethacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexamethacrylate, etc.

[0067] In addition to the above, epoxy methacrylate, urethane methacrylate, polyester methacrylate, and the like can also be used.

[0068] Based on the total amount of acrylic compounds contained in the active energy ray curable resin composition, the content of acrylic compounds satisfying the above formula (1) can be 10% by mass or more, and may be 30% by mass or more, or 50% by mass or more. When the content is 10% by mass or more, the gas barrier properties tend to improve compared to when it is less than 10% by mass. On the other hand, there is no particular upper limit to the content, but it can be 100% by mass.

[0069] If the active energy ray curable resin composition contains an acrylic compound that does not satisfy formula (1) above, the content of the acrylic compound can be 10 to 2000 parts by mass or 50 to 1000 parts by mass per 100 parts by mass of the acrylic compound that satisfies formula (1) above. However, if the content is 10 parts by mass or more, the coatability of the composition (coating liquid) tends to improve, and if it is 2000 parts by mass or less, it tends to maintain good gas barrier properties.

[0070] If the active energy ray curable resin composition contains a carboxyl group-containing acrylic compound that does not satisfy formula (1), the content of the compound can be 10 to 600 parts by mass per 100 parts by mass of the acrylic compound that satisfies formula (1). However, if the content is 10 parts by mass or more, the coatability and adhesion of the composition (coating liquid) tend to improve, and if it is 600 parts by mass or less, it tends to maintain good gas barrier properties. From the viewpoint of achieving a good balance of coating properties, adhesion, and gas barrier properties, the content of the carboxyl group-containing acrylic compound that does not satisfy formula (1) is preferably 10 to 600 parts by mass, 10 to 300 parts by mass, 20 to 300 parts by mass, 20 to 200 parts by mass, or 20 to 100 parts by mass per 100 parts by mass of the acrylic compound that satisfies formula (1).

[0071] From the viewpoint of gas barrier properties, the active energy ray curable resin composition may contain 50% by mass or more of an acrylic compound, and may contain 70% by mass or more, or 80% by mass or more. On the other hand, there is no particular upper limit to the content, but it may be 100% by mass.

[0072] The active energy ray curable resin composition may optionally contain a photoradical generator. Any photoradical generator capable of generating radicals by EB or UV irradiation can be used. The photoradical generator is not particularly limited, but examples include benzyldimethyl ketal, 1-hydroxycyclohexylphenyl ketone, diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane, 2,4,6-trimethylbenzoyldiphenylphosphate, camphorquinone, 9-fluorenone, and diphenyl disulfide.

[0073] The active energy ray curable resin composition may optionally contain a silane coupling agent. From the viewpoint of EB curability and UV curability, a silane coupling agent having an acryloyl group or a methacryloyl group is preferred. Examples of such silane coupling agents include 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, and 3-acryloyloxypropyltrimethoxysilane.

[0074] The thickness of the overcoat layer 20 is set according to the required gas barrier properties, and can be, for example, 0.05 to 10 μm, 0.1 to 5 μm, 0.1 to 2 μm, 0.15 to 2 μm, 0.2 to 2 μm, 0.2 to 1.5 μm, 0.2 to 1 μm, or 0.3 to 1 μm. If the thickness of the overcoat layer 20 is 0.05 μm or more, more preferably 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more, sufficient gas barrier properties are easily obtained. On the other hand, from the viewpoint of improving curability (if the thickness is too thick, curing takes a long time) and from the viewpoint of improving adhesion between the overcoat layer and the inorganic oxide layer, the thickness can be 10 μm or less, more preferably 5 μm or less, 1.5 μm or less, or 1 μm or less.

[0075] <Method for manufacturing gas barrier film> The method for manufacturing a gas barrier film is: A process of forming an inorganic oxide layer on a substrate layer, A step of forming a coating film by applying an active energy ray-curable resin composition onto an inorganic oxide layer, The process includes a step of curing the coating film by irradiating it with active energy rays to form an overcoat layer, The number of acryloyl groups contained in one molecule of the active energy ray-curable resin composition is N A The number of hydroxyl groups is N B In this case, it contains an acrylic compound that satisfies the following formula (1). N A ×2+N B ×3≧5 ···(1) (In the formula, N A ≥ 1 and N B (≥0.)

[0076] An example of a manufacturing procedure for gas barrier films is described below. First, prepare the base layer 10. The base layer 10 may be a commercially available product or may be manufactured by a known method.

[0077] Next, the base layer 30 and the inorganic oxide layer 40, or only the inorganic oxide layer 40, are formed on the base layer 10.

[0078] To form the underlayer 30, for example, an underlayer-forming coating agent can be applied to the base layer 10 by a wet-coat method to form a coating film, and then the coating film can be dried (solvent removed) and hardened. As a method for applying the coating agent, known wet coating methods can be used. Examples of wet coating methods include roll coating, gravure coating, reverse coating, die coating, screen printing, and spray coating. As a method for drying the coating film, known drying methods such as hot air drying, hot roll drying, and infrared irradiation can be used. The drying temperature of the coating film can be, for example, 50 to 200°C. The drying time varies depending on the thickness of the coating film, the drying temperature, etc., but can be, for example, 1 second to 5 minutes. The drying conditions of the coating film should be appropriately determined considering the ease with which the solvent in the coating film dries, the thermal stability of the substrate layer 10, etc.

[0079] The inorganic oxide layer 40 can be formed on the substrate layer 10 or the underlayer 30 by the vacuum deposition method, sputtering method, ion plating method, or plasma vapor deposition (CVD) method described above.

[0080] Next, the overcoat layer 20 is formed. The overcoat layer 20 can be formed, for example, by applying an overcoat layer forming coating agent (the above-mentioned active energy ray curable resin composition) onto the inorganic oxide layer 40 by a wet coating method to form a coating film, and then curing the coating film by EB irradiation or UV irradiation. The irradiation conditions for the active energy rays depend on the thickness of the overcoat layer 20, but the acceleration voltage can be set to 10-300kV and the irradiation dose to 15-120kGy. If the acceleration voltage is within the above range, the active energy rays can easily penetrate sufficiently deep into the thickness direction of the coating film, and the deterioration of the inorganic oxide layer, undercoat layer, substrate layer, etc., by the active energy rays can be easily suppressed. Furthermore, if the irradiation dose is within the above range, it is easy to form the desired cross-linked structure inside the layer while suppressing yellowing and changes in the mechanical properties of the overcoat layer 20. The method for applying the coating agent can be the same as that described in the explanation of the process for forming the base layer 30. The overcoat layer 20 may be formed by a single application and curing, or it may be formed by repeating the application and curing process multiple times using the same type of coating agent or different types of coating agents.

[0081] The overcoat layer 20 formed as described above is a cured product of a coating agent (active energy ray curable resin composition) having a crosslinked structure. Here, "having a crosslinked structure" means that the molecular chains of the reactive compound, including the acrylic compound, take on a network-like three-dimensional structure. The presence of the crosslinked structure can be confirmed by various analyses, and analytical methods include Fourier transform infrared spectroscopy, solid-state NMR spectroscopy, X-ray photoelectron spectroscopy, dynamic viscoelasticity measurement, and gel fraction measurement.

[0082] The gas barrier film may be further provided with, if necessary, a printed layer, a protective layer, a light-shielding layer, an adhesive layer, a heat-sealable heat-sealable layer, or other functional layers.

[0083] <Packaging films and packaging materials> The packaging film comprises the aforementioned gas barrier film and a heat-sealable layer provided on the overcoat layer of the gas barrier film. By preparing one or more of these packaging films and heat-sealing the edges with the heat-sealable layers facing each other, a packaging material can be formed. In other words, the packaging material is made by forming a bag from the packaging film.

[0084] Examples of heat-sealable layers include CPP (unoriented polypropylene). The heat-sealable layer can be laminated onto the substrate layer using known adhesives such as polyurethane, polyester, or polyether-based adhesives by known dry lamination methods, extrusion lamination methods, etc.

[0085] By making both the base layer and the heat-sealed layer from polypropylene, the polypropylene content in the packaging film and packaging material can be set to 90% by mass or more. As a result, the packaging film and packaging material become so-called monomaterial materials with excellent recyclability. [Examples]

[0086] The gas barrier films of this disclosure will be further described with reference to examples and comparative examples. This disclosure is not limited in any way by the specific details of the examples and comparative examples.

[0087] (Example 1) [Base material layer preparation] As the base layer 10, a 20 μm thick biaxially oriented polypropylene film (VPH2011, manufactured by AJPlast) was prepared, with one side subjected to corona treatment.

[0088] [Inorganic oxide layer formation] Using a vacuum deposition apparatus with electron beam heating, a mixed material containing two or more types of silicon, including metallic silicon, silicon monoxide, and silicon dioxide, was evaporated to form an inorganic oxide layer 40 (silicon oxide deposition layer) with a thickness of 30 nm on the corona-treated surface of the substrate layer 10.

[0089] [Overcoat layer formation] A coating film was formed on the inorganic oxide layer 40 by coating it with glycerin diacrylate (product name: M-920, manufactured by Toagosei Co., Ltd.) as a coating solution (active energy ray curable resin composition) using a flexographic printing press. Then, the coating film was cured by EB irradiation using an electron beam irradiation device manufactured by I-Electron Beam Co., Ltd., at an acceleration voltage of 120 kV, an irradiation dose of 15 kGy, and under a nitrogen atmosphere with an oxygen concentration of 100 ppm or less. The thickness of the resulting overcoat layer was 1 μm. This resulted in a gas barrier film having a substrate layer 10 / inorganic oxide layer 40 / overcoat layer 20 in this order.

[0090] (Examples 2-6 and Comparative Examples 1-3) A gas barrier film was obtained in the same manner as in Example 1, except that the acrylic compounds shown in Table 1 were used. The value of formula (1) and the molecular weight of each compound are also shown in Table 1.

[0091] (Comparative Example 4) A gas barrier film was obtained in the same manner as in Example 1, except that an overcoat layer was not formed.

[0092] The details of the acrylic compounds used are as follows: • Tris(2-hydroxyethyl)isocyanurate triacrylate (product name: A-9300, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) • 2-Acryloyloxyethyl-2-hydroxyethyl phthalate (Product name: Light Acrylate HOA-MPE(N), manufactured by Kyoeisha Chemical Co., Ltd.) • Bisphenol A diglycidyl ether acrylic acid adduct (Product name: Epoxy Ester 3000A, manufactured by Kyoeisha Chemical Co., Ltd.) • Mixture of tris(2-hydroxyethyl)isocyanurate diacrylate and tris(2-hydroxyethyl)isocyanurate triacrylate (Product name: M-313, manufactured by Toagosei Co., Ltd.) • Glycerol 1,3-diglycerolate diacrylate (product name: Glycerol 1,3-diglycerolate diacrylate, manufactured by Sigma-Aldrich) • Butyl acrylate (product name: Butyl Acrylate, manufactured by Tokyo Chemical Industry Co., Ltd.) • Dipropylene glycol diacrylate (product name: Dipropylene Glycol Diacrylate, manufactured by Tokyo Chemical Industry Co., Ltd.) • Neopentyl glycol diacrylate (product name: A-NPG, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0093] [Table 1]

[0094] The following evaluations were performed on the gas barrier films obtained in each example. The results are shown in Table 2.

[0095] (curable) The hardening properties of the gas barrier film's overcoat layer were confirmed by the tackiness felt when rubbing it with a latex glove. A score of ○ was given if no rubbing marks were left on the overcoat layer and no stickiness was detected, while a score of × was given if stickiness was present.

[0096] (Oxygen barrier properties) Using an oxygen permeability measuring device (product name: OXTRAN-2 / 20, manufactured by MOCON), the oxygen permeability (cc / (m³)) of the gas barrier film obtained in each example was measured under an atmosphere of 30°C and 70% RH (relative humidity). 2 The temperature (day·atm) was measured. In cases where the curing performance evaluation was negative (×), oxygen barrier performance evaluation was not performed because the stickiness of the overcoat layer surface made handling difficult.

[0097] As shown in Table 2, by using an acrylic compound in which the value of formula (1) above is 5 or greater, a dense film structure is formed due to the improved crosslinking density by the acryloyl groups, resulting in excellent gas barrier properties that are less permeable to oxygen molecules.

[0098] [Table 2]

[0099] Number of hydroxyl groups in one molecule: N B In Example 6, which used an acrylic compound with a ratio of 3, extremely excellent oxygen barrier properties were observed. This is thought to be because the amount of hydroxyl groups positioned inside the film increased, improving the effect of suppressing the diffusion of oxygen molecules permeating the film.

[0100] As is clear from Comparative Examples 1 to 3, when acrylic compounds with a value of less than 5 in formula (1) were used, the curing properties were either insufficient or, even if the curing properties were sufficient, good oxygen barrier properties could not be obtained.

[0101] (Example 7) As the acrylic compound, a mixture of 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid (product name: Light Acrylate HOA-MPE(N), manufactured by Kyoeisha Chemical Co., Ltd.) (A) and 2-acryloyloxyethyl hexahydrophthalic acid (product name: Light Acrylate HOA-HH(N), manufactured by Kyoeisha Chemical Co., Ltd., the value of formula (1) above is less than 5) (B) was used in a mass ratio of A:B = 50:50. Except for this, a gas barrier film was obtained in the same manner as in Example 1.

[0102] (Example 8) Instead of B, 2-acryloyloxyethyl phthalic acid (product name: M-5400, manufactured by Toagosei, the value of formula (1) above is less than 5) (C) was used. Except for this, a gas barrier film was obtained in the same manner as in Example 7.

[0103] (Adhesion) The adhesion between the overcoat layer and the inorganic oxide layer was evaluated using the "X-cut tape method" of JIS K 5400. In this method, a thin cross-shaped cut is made in the overcoat layer with a cutter, cellophane tape is applied over the cut, and the degree of the overcoat layer remaining on the film after the tape is peeled off is observed. A circle (○) indicates that the overcoat layer did not peel off at all, and a cross (×) indicates that even a small amount peeled off.

[0104] [Table 3]

[0105] As shown in Table 3, the adhesion test results for Examples 7 and 8 were both good. By using an acrylic compound with a value of formula (1) of 5 or more (molecular weight 308) along with a carboxyl group-containing acrylic compound with a value of formula (1) of less than 5 (molecular weight 270 or 264), a synergistic effect was demonstrated in improving the adhesion between the overcoat layer and the inorganic oxide layer, as well as the oxygen barrier properties.

[0106] (Example 9) As the acrylic compound, a mixture of glycerin 1,3-diglycerolate diacrylate (product name: Glycerol 1,3-diglycerolate diacrylate, manufactured by Sigma-Aldrich) (D) and 2-acryloyloxyethyl hexahydrophthalic acid (product name: Light Acrylate HOA-HH(N), manufactured by Kyoeisha Chemical Co., Ltd., the value of formula (1) above is less than 5) (B) was used, in a mass ratio of D:B = 20:80. The thickness of the overcoat layer was 0.5 μm. Except for these factors, a gas barrier film was obtained in the same manner as in Example 1.

[0107] (Example 10) Instead of B, 2-acryloyloxyethyl phthalic acid (product name: M-5400, manufactured by Toagosei, the value of formula (1) above is less than 5) (C) was used. Except for this, a gas barrier film was obtained in the same manner as in Example 9.

[0108] [Table 4]

[0109] As shown in Table 4, the adhesion test results for Examples 9 and 10 were both good. By using an acrylic compound with a value of 5 or more in formula (1) (molecular weight 348) along with a carboxyl group-containing acrylic compound with a value of less than 5 in formula (1) (molecular weight 270 or 264), a synergistic effect was demonstrated in improving the adhesion between the overcoat layer and the inorganic oxide layer, as well as the oxygen barrier properties, even with a thin overcoat layer of 0.5 μm thickness.

[0110] While embodiments and examples of the present disclosure have been described above, the specific configuration of the present disclosure is not limited to those described above, and modifications, combinations, etc., of the configuration are possible within the scope of the gist of the present disclosure. [Explanation of Symbols]

[0111] 10...Base layer, 20...Overcoat layer, 30...Undercoat layer, 40...Inorganic oxide layer, 100, 200...Gas barrier film.

Claims

1. A process of forming an inorganic oxide layer on a substrate layer, The process involves applying an active energy ray-curable resin composition onto the inorganic oxide layer to form a coating film, The process includes a step of curing the aforementioned coating film by irradiating it with active energy rays to form an overcoat layer, The above-mentioned active energy ray curable resin composition has a number of acryloyl groups contained in one molecule of N Ａ The number of hydroxyl groups is N Ｂ In this case, the compound includes an acrylic compound satisfying the following formula (1A) and a carboxyl group-containing acrylic compound satisfying the following formula (1B), The molecular weight of the acrylic compound is 300 to 1900. A method for producing a gas barrier film, wherein the molecular weight of the carboxyl group-containing acrylic compound is less than the molecular weight of the acrylic compound. 15≧N Ａ ×2+N Ｂ ×3≧6 ・・・(1A) (In formula (1A), N Ａ ≥ 1 and N Ｂ (≥ 1.) N Ａ ×2+N Ｂ ×3<5 ・・・(1B) (In formula (1B), N Ａ is ≧ 1 and N Ｂ = 0.)

2. The material comprises a base layer, an inorganic oxide layer, and an overcoat layer in this order. The overcoat layer is a cured product of an active energy ray curable resin composition having a crosslinked structure. The above-mentioned active energy ray curable resin composition has a number of acryloyl groups contained in one molecule of N Ａ The number of hydroxyl groups is N Ｂ In this case, the compound includes an acrylic compound satisfying the following formula (1A) and a carboxyl group-containing acrylic compound satisfying the following formula (1B), The molecular weight of the acrylic compound is 300 to 1900. A gas barrier film in which the molecular weight of the carboxyl group-containing acrylic compound is less than the molecular weight of the acrylic compound. 15≧N Ａ ×2+N Ｂ ×3≧6 ・・・(1A) (In formula (1A), N Ａ ≥ 1 and N Ｂ (≥ 1.) N Ａ ×2+N Ｂ ×3<5 ・・・(1B) (In formula (1B), N Ａ ≥ 1 and N Ｂ (= 0.)

3. In formula (1A), the N Ｂ The gas barrier film according to claim 2, wherein ≥ 3.

4. The gas barrier film according to claim 2, wherein the molecular weight of the carboxyl group-containing acrylic compound is 100 or more and 500 or less.

5. The gas barrier film according to claim 2, wherein the base layer contains a polyolefin resin.

6. The gas barrier film according to claim 2, wherein the thickness of the overcoat layer is 0.15 to 2 μm.

7. A packaging film comprising a gas barrier film according to any one of claims 2 to 6, and a heat-sealable layer provided on the overcoat layer of the gas barrier film.

8. A packaging material made from the packaging film described in claim 7.

Images