JP5625346B2 - Biaxially oriented polyester film for vapor deposition - Google Patents

Description

  The present invention relates to a biaxially oriented polyester film for vapor deposition and a gas barrier film. In particular, it relates to a biaxially oriented polyester film for vapor deposition and a gas barrier film using a polyurethane-based resin as an anchor coat layer, and is particularly suitable for a biaxial material for vapor deposition suitably used for packaging materials and industrial materials such as foods, pharmaceuticals and electronic parts. The present invention relates to an oriented polyester film and a gas barrier film.

  Polyethylene terephthalate biaxially oriented film, which is a typical example of polyester film, has excellent mechanical strength, thermal characteristics, humidity characteristics, and many other excellent characteristics, so it can be used for industrial materials, magnetic recording materials, optical materials, information communication materials, and packaging. It is used in a wide range of fields such as materials.

  However, polyethylene terephthalate biaxially oriented film has a large gas permeability such as oxygen and water vapor, so when used for packaging products such as general foods, retort-treated foods and pharmaceuticals, it will be altered and deteriorated by long-term storage. May occur.

  Therefore, vapor deposition in which a vapor deposition film of an inorganic oxide such as aluminum oxide or silicon oxide is provided on one surface of a thermoplastic resin film such as a polyester resin film using a physical vapor deposition method such as a vacuum vapor deposition method. Films have also been proposed.

  These gas barrier films having an inorganic oxide vapor-deposited thin film layer have the advantage that they are transparent so that the contents are visible and can be used for cooking using a microwave oven. The property greatly depends on the surface roughness, heat shrinkability, etc. of the thermoplastic resin film as the base material and is unstable.

  Therefore, conventionally, it is widely known that a gas barrier film is produced by treating the surface of a base film with an anchor coating agent and then depositing a metal and / or a metal oxide.

  For example, Patent Document 1 discloses a urethane resin having gas barrier properties and is said to be able to be used as an anchor coating agent. However, there is no example used as an anchor coating agent, and gas barrier properties and water-resistant adhesion properties are disclosed. Is insufficient.

  Patent Document 2 discloses a gas barrier film in which a polyurethane-based resin layer and an inorganic oxide layer are formed in this order on at least one surface of a polyester-based resin film, but water-resistant adhesion is insufficient.

JP 2007-217642 A International Publication No. 2008/035557 Pamphlet

  An object of the present invention is to eliminate the above-described problems of the prior art. That is, an object of the present invention is to provide a biaxially oriented polyester film for vapor deposition and a gas barrier film which are excellent in gas barrier properties such as oxygen and water vapor and have excellent water-resistant adhesion.

The biaxially oriented polyester film for vapor deposition and gas barrier film of the present invention are:
(1) A biaxially oriented polyester film for vapor deposition comprising an anchor coat layer made of a polyurethane resin (A) on at least one side of the polyester film, the differential scanning of the biaxially oriented polyester film for vapor deposition The endothermic peak before crystal melting obtained by calorimeter measurement is 180 ° C. or higher and 220 ° C. or lower, and the polyurethane resin (A) is a resin comprising a polyisocyanate component (A1) and a polyol component (A2). The polyisocyanate component (A1) contains an araliphatic diisocyanate (A1A) and / or an alicyclic diisocyanate (A1B), and the polyol component (A2) contains at least a polyhydroxyalkanoic acid (A2C), Furthermore, the C2-C6 alkane polyol (A2A) and / or C2 Polyoxyalkylene glycol (A2B) deposited biaxially oriented polyester film comprising a 6, a.

As a more preferable aspect,
(2) The biaxially oriented polyester film for vapor deposition according to (1), wherein the polyisocyanate component (A1) contains xylylene diisocyanate (A1a1) and / or hydrogenated xylylene diisocyanate (A1b1),
(3) The biaxially oriented polyester film for vapor deposition according to (1) or (2), wherein the polyol component (A2) contains ethylene glycol (A2a1) and / or diethylene glycol (A2b1),
(4) A gas barrier film comprising a metal and / or metal oxide layer laminated on the anchor coat layer of the biaxially oriented polyester film for vapor deposition according to any one of (1) to (3),
It is.

  The biaxially oriented polyester film for vapor deposition of the present invention has not only excellent oxygen barrier property and water vapor barrier property but also water resistance by laminating a layer made of metal and / or metal oxide on the anchor coat layer. Since the gas barrier film which has it is obtained, it can be used conveniently as packaging materials, such as a general food, a retort processing food, and a pharmaceutical.

It is the schematic of peel strength measurement. It is an example of a minute endothermic peak before crystal melting.

  In the present invention, an anchor coat layer is provided on at least one surface of a polyester film (base film) made of a polyester resin to obtain a biaxially oriented polyester film for vapor deposition.

  Here, the polyester resin is a general term for polymer compounds in which the main bond in the main chain is an ester bond, and can usually be obtained by polycondensation reaction of a dicarboxylic acid component and a glycol component.

  The dicarboxylic acid component used here is mainly terephthalic acid. As long as the effects of the present invention are not impaired, other dicarboxylic acid components such as naphthalenedicarboxylic acid, isophthalic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodiumsulfoisophthalic acid, phthalic acid and the like Aromatic dicarboxylic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, fumaric acid and other aliphatic dicarboxylic acids, cyclohexyne dicarboxylic acid and other alicyclic dicarboxylic acids, p-oxybenzoic acid An oxycarboxylic acid such as can be used in combination.

  On the other hand, the glycol component is mainly ethanediol. As long as the effects of the present invention are not inhibited, other glycol components, for example, glycerides such as propanediol, pentanediol, hexanediol and neopentylglycol, alicyclic glycols such as cyclohexanedimethanol, bisphenol A and bisphenol S Aromatic glycols such as can be used in combination.

  Furthermore, polyethers such as polyethylene glycol and polytetramethylene glycol may be copolymerized. These dicarboxylic acid components and glycol components may be used in combination of two or more, or two or more polyesters may be blended and used. Further, two or more layers may be used as a co-extruded laminated film.

  Examples of polyester polymerization catalysts include alkali metal compounds, alkaline earth metal compounds, zinc compounds, lead compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, and titanium compounds, among which germanium compounds and antimony compounds. And titanium compounds are particularly preferably used. Moreover, when manufacturing polyester, coloring inhibitors, such as a phosphorus compound, can be used.

  The polyester subjected to the polycondensation reaction under high temperature and reduced pressure is further subjected to a solid phase polymerization reaction under reduced pressure or in an inert gas atmosphere at a temperature lower than its melting point to reduce the acetaldehyde content, The amount of carboxyl end groups can be adjusted.

  In this invention, it is preferable that a base film contains a particle | grain with an average particle diameter of 0.01-5 micrometers from a viewpoint of workability, such as handleability and lamination, printing, etc. The particles may be known particles for film addition. For example, internal particles, inorganic particles, and organic particles are preferable. Preferably it is 0.01 to 3 weight%, More preferably, 0.03 to 3 weight% is contained.

  Examples of inorganic particles include wet and dry silica, colloidal silica, aluminum silicate, titanium oxide, calcium carbonate, calcium phosphate, barium sulfate, aluminum oxide, mica, kaolin, clay, and organic particles include styrene, silicone, acrylic Particles containing as constituents acids, methacrylic acids, polyesters, divinyl compounds and the like can be used. Among them, it is preferable to use inorganic particles such as wet and dry silica and alumina, and particles containing styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene and the like as constituent components. Furthermore, these internal particles, inorganic particles, and organic particles may be used in combination of two or more.

In addition, the base film contains, for example, an antistatic agent, a heat stabilizer, an antioxidant, a crystal nucleating agent, a weathering agent, an ultraviolet absorber, a pigment, and a dye as long as the effects of the present invention are not hindered. It is possible.
In the film for vapor deposition of the present invention, it is necessary that an anchor coat layer made of a polyurethane resin is formed on at least one surface of the polyester film (base film). The polyurethane resin (A) is generally composed of a polyisocyanate component (A1) and a polyol component (A2), wherein the isocyanate group of the polyisocyanate component (A1) is based on the hydroxyl group of the polyol component (A2). It is possible to use those obtained by reacting at an excess ratio and obtained by carrying out a chain extension reaction or a crosslinking reaction with an amine component.

  Examples of the polyisocyanate component (A1) include aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates.

  Aromatic polyisocyanates include, for example, 4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate or mixtures thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or mixtures thereof (TDI), 4,4'-toluidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or mixtures thereof, 4,4'-diphenyl diisocyanate, 4,4'-diphenyl ether Aromatic diisocyanates such as diisocyanates are mentioned.

  Examples of the araliphatic polyisocyanate include araliphatic diisocyanate (A1A). Moreover, as araliphatic diisocyanate (A1A), xylene diisocyanate (A1a1) is mentioned, for example. Further, examples of xylene diisocyanate (A1a1) include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI). ), Ω, ω′-diisocyanate-1,4-diethylbenzene and the like.

  Examples of the alicyclic polyisocyanate include alicyclic diisocyanate (A1B). Examples of the alicyclic diisocyanate (A1B) include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4′-, 2,4′- or 2, 2'-dicyclohexylmethane diisocyanate or a mixture thereof (H12MDI), 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or a mixture thereof (hydrogenated xylylene diisocyanate, H6XDI), bis (isocyanatomethyl) norbornane ( NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexanedii Cyanate and the like. Especially, in order to fully express the effect of this invention, it is preferable to use hydrogenated xylylene diisocyanate (A1b1).

  Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,2-, 2,3- or 1,3-butylene diisocyanate, 2,4,4. -Or aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate.

  In addition, as the polyisocyanate component, a multimer (for example, dimer, trimer, pentamer, heptamer, etc.) of the above polyisocyanate component, for example, the above polyisocyanate component or multimer, Biuret modified product produced by reaction with water, allophanate modified product produced by reaction with monool or polyhydric alcohol (described later), oxadiazine trione modified product produced by reaction with carbon dioxide, and low molecular weight Examples include polyol modified products produced by reaction with polyol (described later).

  These polyisocyanate components can be used alone or in combination of two or more.

  In this invention, it is preferable that a polyisocyanate component (A1) uses an araliphatic diisocyanate (A1A) and / or an alicyclic diisocyanate (A1B). More preferably, xylene diisocyanate (A1a1) and / or hydrogenated xylylene diisocyanate (A1b1) is preferably used.

  A polyurethane-based resin containing an aromatic ring in its structure can cause a π-electron interaction between aromatic rings. Moreover, since a nitrogen atom with high electronegativity is contained, a hydrogen bond can be formed between polymer chains. Furthermore, the aromatic ring typified by XDI and the aliphatic ring typified by H6XDI have a structure with a relatively hard molecular chain, and the polyurethane resin containing the structure has a high glass transition temperature and thermal dimensional stability. Is excellent.

  The polyurethane resin containing an aromatic ring and an aliphatic ring skeleton in the structure has the above-mentioned characteristics, and these characteristics are preferred embodiments in the present invention from the following viewpoints. As a factor for determining the gas barrier property of a film in which an anchor coat layer made of a polyurethane resin is formed on at least one surface of a polyester film and a metal and / or metal oxide layer is formed on the surface, a metal and / or metal oxide is used. The surface on which the layer is formed, that is, the surface roughness of the polyurethane resin layer, the thermal dimensional stability, the crystallinity, the surface free energy, and the like can be mentioned. These factors are not low in proportion due to the polymer structure forming the polyurethane resin layer. For example, thermal dimensional stability and crystallinity are due to the cohesive strength and skeletal structure of the polymer. That is, polymer chains containing functional groups capable of intermolecular interaction such as hydrogen bonding, π-electron interaction, or electrostatic interaction, aromatic rings, or atoms in the structure will strongly aggregate using the interaction force as a driving force. And As a result, the cohesive energy density and orientation are increased, and the thermal dimensional stability and crystallinity are improved. For these reasons, alicyclic compounds and aromatic compounds are preferred as the polyurethane-based resin.

  In addition, when a metal and / or metal oxide layer is formed by vapor deposition, the site where the vapor deposited molecules adsorb is high in free energy, and functional groups and aromatics capable of intermolecular interaction with the metal and / or metal oxide. It is considered a ring. By synthesizing a urethane-based resin using a polyol having a carbon number of 6 or less and a diamine component, which will be described later, a urethane bond site, a urea bond site, an aromatic ring, and an aliphatic ring, which are considered to be vapor-deposited molecule adsorption sites, are spaced at regular short intervals. Since they can be arranged, a dense metal and / or metal oxide layer can be formed. For this reason, the polyisocyanate component has a narrow interval between isocyanate groups, an aromatic ring and / or an aliphatic ring exists between the isocyanate groups, and XDI and / Alternatively, it is preferable to use H6XDI.

  Examples of the polyol component (A2) include ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 2-methyl-1,3-propanediol, 1, 5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, alkane (carbon number 7 to 22) diol, Diethylene glycol, trioxyethylene glycol, tetraoxyethylene glycol, pentaoxyethylene glycol, hexaoxyethylene glycol, dipropylene glycol, trioxypropylene glycol, tetraoxypropylene glycol, pentaoxypropylene glycol , Low molecular weight diols, such as hexa-oxypropylene glycol, such as polyhydroxy acids such as dimethylolpropionic acid. These polyol components can be used alone or in combination of two or more. In the present invention, the polyol component (A2) is preferably a low molecular weight polyol. Here, the low molecular weight polyol refers to a polyol having a number average molecular weight of less than 400.

  In the present invention, the polyol component (A2) contains at least a polyhydroxyalkanoic acid (A2C), and further contains an alkane polyol having 2 to 6 carbon atoms (A2A) and / or a polyoxyalkylene glycol having 2 to 6 carbon atoms (A2B). ) Is particularly preferred.

  Specifically, as the alkane polyol having 2 to 6 carbon atoms (A2A), for example, ethylene glycol (A2a1), 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3 -Butylene glycol, 1,2-butylene glycol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol Etc. Preferably, ethylene glycol (A2a1), 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol and the like can be mentioned. Particularly preferred is ethylene glycol (A2a1).

Examples of the polyoxyalkylene glycol (A2B) having 2 to 6 carbon atoms include diethylene glycol (A2b1), trioxyethylene glycol, tetraoxyethylene glycol, pentaoxyethylene glycol, hexaoxyethylene glycol, dipropylene glycol, and trioxypropylene glycol. , Tetraoxypropylene glycol, pentaoxypropylene glycol, hexaoxypropylene glycol and the like. Preferably, diethylene glycol, trioxyethylene glycol, dipropylene glycol, and trioxypropylene glycol are used. Preferably, it is diethylene glycol (A2b1).
Examples of the polyhydroxyalkanoic acid (A2C) include dimethylolacetic acid, dimethylollactic acid, dimethylolpropionic acid, and dimethylolbutanoic acid. Preferably, dimethylolpropionic acid is used.

  In the present invention, the polyol component (A2) preferably contains polyhydroxyalkanoic acid (A2C), and further contains ethylene glycol (A2a1) and / or diethylene glycol (A2b1).

  As described above, when a metal and / or metal oxide layer is formed by vapor deposition, the sites where the vapor deposition molecules adsorb are considered to be functional groups and aromatic rings. By synthesizing a urethane-based resin using a polyol having 6 or less carbon atoms and a diamine component, which will be described later, a urethane bond site, a urea bond site, an aromatic ring, and an aliphatic ring, which are considered as vapor-deposited molecule adsorption sites, are arranged at a constant short interval. Since they can be arranged, a dense metal and / or metal oxide layer can be formed. For these reasons, the polyol component and the diamine component described below are preferably polyol components having 6 or less carbon atoms, more preferably 4 or less carbon atoms, and most preferably 2 or less carbon atoms.

  In particular, when a urethane resin is synthesized using ethylene glycol (A2a1) and / or diethylene glycol (A2b1) as a polyol component and xylene diisocyanate (A1a1) and / or hydrogenated xylylene diisocyanate (A1b1) as a polyisocyanate component, a urethane group, Since the intervals between the aromatic ring and the aliphatic ring are arranged at almost equal intervals at the atomic level, the densest metal and / or metal oxide layer can be formed.

  Moreover, a diamine component can be used as a chain extender or a crosslinking agent as needed. Examples of the diamine include hydrazine and aliphatic diamines (for example, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethyl). Hexamethylenediamine and octamethylenediamine, etc.), aromatic amines (eg m- or p-phenylenediamine, 1,3- or 1,4-xylylenediamine or mixtures thereof), alicyclic diamines [eg water Added xylylenediamine, bis (4-aminocyclohexyl) methane, isophoronediamine and bis (4-amino-3-methylcyclohexyl) methane, etc.], and others, 2-hydrazinoethanol, 2-[(2-amino Ethyl) amino] Diamine having a hydroxyl group of Nord and the like can be used as well.

  Among these diamine components, from the viewpoints of orientation, thermal dimensional stability, and crystallinity, the low molecular weight diamine component having 8 or less carbon atoms, preferably a diamine having 6 or less carbon atoms, particularly hydrazine, ethylenediamine, tetra Methylenediamine, pentamethylenediamine, hexamethylenediamine, 2-hydrazinoethanol, 2-[(2-aminoethyl) amino] ethanol and the like are used. These diamine components can be used alone or in combination of two or more. Furthermore, if necessary, a triamine or higher polyamine component can be used in combination.

  The number average molecular weight of the polyurethane-based resin synthesized using the above raw materials is preferably selected from the range of about 800 to 1,000,000, more preferably 800 to 200,000, still more preferably about 800 to 100,000. can do. By setting the molecular weight to 800 or more, the coating film formed from the polyurethane resin exhibits sufficient strength. Further, when coating on a polyester film, the polyurethane resin itself has a cohesive force, which facilitates film formation. On the other hand, by setting the molecular weight to 1,000,000 or less, the resin viscosity of the polyurethane-based resin can be kept low even in a solvent, and the workability at the time of coating on a polyester film becomes good.

  The anchor coat layer can be formed by coating a polyurethane resin on the polyester film. Examples of the solvent for the coating liquid for forming the polyurethane resin layer of the present invention include toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dimethylformamide, dimethylacetamide, and methanol. Ethanol, water and the like can be exemplified, and the properties of the coating liquid may be either an emulsion type or a dissolution type.

  In the coating liquid used in the present invention, a heat stabilizer, an antioxidant, a reinforcing agent, a pigment, a deterioration preventing agent, a weathering agent, a flame retardant, a plasticizer, a release agent, a lubricant, etc. May be added.

  Examples of the heat stabilizer, antioxidant and deterioration inhibitor include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds and alkali metal halides or mixtures thereof.

  Examples of the reinforcing agent include clay, talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, Examples include zinc oxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate whisker, boron nitride, graphite, glass fiber, and carbon fiber.

  An inorganic layered compound may be mixed in the coating solution used in the present invention. Preferable examples of inorganic layered compounds include montmorillonite, beidellite, saponite, hectorite, saconite, vermiculite, fluoric mica, muscovite, paragonite, phlogopite, leoprite, margarite, clintonite, and anandite. Swellable fluorine mica or montmorillonite is particularly preferably used.

  These inorganic layered compounds may be naturally occurring, artificially synthesized or modified, and those treated with an organic substance such as an onium salt. .

  Examples of the method for laminating the anchor coat layer on the polyester film include a hot melt coating method, an in-line coating method, and an offline coating method. When using the in-line coating method or offline coating method, create a coating solution in which the resin or compound constituting the anchor coating layer is dissolved and / or dispersed in water or an organic solvent, and apply the coating solution to the polyester film. It is preferable to do.

  In addition, an anchor coating layer may be provided by applying a coating solution on a biaxially oriented polyester film after completion of orientation by an off-line coating method or the like, but at least one side of the polyester film before orientation crystallization is completed is anchor-coated. An in-line coating method in which a coating liquid for forming a layer is applied and heat-treated to complete orientation crystallization of the polyester film and to form an anchor coat layer is preferable in that the anchor coat layer can be formed uniformly. The in-line coating method can be performed according to a known method. However, the crystal orientation is different in that it prevents ink or vapor deposition film pinholes due to adhesion of dust in the process, or forms a thin anchor coat layer uniformly. A method of applying a coating solution for forming an anchor coat layer on a polyester film before completion, followed by drying, stretching, and heat treatment to complete oriented crystals of the polyester film, that is, anchor coating in the manufacturing process of the biaxially oriented polyester film An in-line coating method for forming a layer is more preferable. When the anchor coat layer is formed by an in-line coating method, it is preferable to use a water-soluble and / or water-dispersible resin or compound that is advantageous in terms of explosion-proof equipment and environmental pollution, and the urethane resin is also water-soluble. It is preferable to use a water-dispersible resin or compound. Thereby, water can be used as a solvent for the coating agent, which is preferable.

  A water-soluble organic compound, a surfactant or the like may be added to the coating solution, and any coating material produced by a conventionally known method can be used. When the anchor coat layer is formed by the in-line coating method, the adhesion with the metal and / or metal oxide layer, the gloss of the coating film, and the adhesion with the printing ink are excellent.

  The polyester film of the present invention has an anchor coat layer formed on at least one surface thereof, and the surface free energy of the polyester film on the surface on which the anchor coat layer is formed is preferably 45 to 60 mN / m. Also, on the surface where the anchor coat layer is not provided, the polyester on the surface can be easily applied to the film surface by bonding with other materials as a packaging material, coating such as an adhesive, printing or vapor deposition of a metal compound, etc. The surface free energy of the film is preferably 45 to 60 mN / m.

  Examples of the method for setting the surface free energy to such a preferable range include a method of performing a surface treatment by corona discharge or the like on the film surface in air or a nitrogen gas atmosphere, a method of performing a surface treatment by a flame, and the like.

  The thickness of the anchor coat layer is not particularly limited, but is usually 0.001 μm to 1 μm, preferably 0.005 μm to 0.3 μm, more preferably 0.01 μm to 0.1 μm, and particularly preferably 0.02 μm. It is desirable that it is 0.07 μm or less. If the anchor coat layer is too thick, the deposited film may be whitened when receiving heat of about 200 ° C. and the gloss may be reduced. If it is too thin, the adhesion between the metal and / or metal oxide layer and the anchor coat layer may be reduced. May be inferior.

  In addition, various additives such as inorganic and organic particles, lubricants, antistatic agents, weathering agents, heat resistance agents, dyes, pigments and the like may be added to the anchor coat layer within a range that does not impair the effects of the present invention. Good.

  In the biaxially oriented polyester film for vapor deposition of the present invention, it is essential that a minute endothermic peak (hereinafter sometimes referred to as Tmeta) before crystal melting obtained by differential scanning calorimetry is 180 ° C. or higher and 220 ° C. or lower. When Tmeta is less than 180 ° C., the strength of the film is insufficient or the flatness is deteriorated, so that handling in the processing step becomes difficult. If it exceeds 220 ° C., the structure of the polyurethane-based resin of the anchor coat layer changes, and the water-resistant adhesion (described later) between the anchor coat layer and the metal and / or metal oxide layer decreases.

  This minute endothermic peak Tmeta is observed as a minute endothermic peak at the temperature corresponding to the heat treatment temperature of the film (when it overlaps with the melting endothermic curve of the film, it may be a ladder peak), and in order to make Tmeta within the above preferred range Can be achieved by changing the heat treatment temperature during film formation. The heat treatment temperature is preferably 180 ° C. or more and 225 ° C. or less, although it varies depending on the thickness of the film and the film forming speed. The details of the film forming method and the heat treatment step of the film of the present invention will be described later.

  The biaxially oriented polyester film for vapor deposition of the present invention preferably has a water-resistant adhesive force between the anchor coat layer and the metal and / or metal oxide layer of 1 N / 15 mm or more and 10 N / 15 mm or less. The biaxially oriented polyester film for vapor deposition of the present invention can be suitably used as a gas barrier film in which a layer comprising a metal and / or a metal oxide is laminated on the anchor coat layer. When the peel strength between the layers is less than 1 N / 15 mm, in the package using the gas barrier film, when the contents are actually filled or transported, the layers made of metal and / or metal oxide are deposited. Delamination is likely to occur between the layers of the biaxially oriented polyester film for use, and when such delamination occurs, it leads to deterioration of the appearance and gas barrier properties, which causes a problem. In order to increase the peel strength to more than 10 N / 15 mm, an ion sputtering deposition method or the like that can apply a large energy to the metal and / or metal oxide when laminating a layer made of metal and / or metal oxide is used. Although it is necessary to adopt this, the production speed is slow, which may increase the cost. Further, in order to prevent delamination when filling heavy contents, the peel strength is more preferably 1.5 N / 15 mm or more and 10 N / 15 mm or less, and 2.0 N / 15 mm or more and 10 N / More preferably, it is 15 mm or less.

  Although the manufacturing method of the biaxially-oriented polyester film for packaging of this invention is demonstrated concretely below, this invention is not limited to the following manufacturing methods. First, the polyester resin using the polyethylene terephthalate used in the polyester film of the present invention can be a commercially available polyethylene terephthalate resin as it is, but it is produced through a polycondensation reaction as follows. Also good.

  To a mixture of 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol, 0.09 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide are added and gradually heated, finally at 220 ° C. Transesterification is performed while distilling methanol to synthesize a polyethylene terephthalate precursor. Next, 0.02 part by weight of an 85% aqueous solution of phosphoric acid is added to the precursor, and the mixture is transferred to a polycondensation reaction kettle. The reaction system is gradually depressurized while being heated and heated in a polycondensation reaction kettle, and a polycondensation reaction is performed at 290 ° C. under a reduced pressure of 1 hPa to obtain a polyethylene terephthalate resin having a desired molecular weight. In addition, when adding particles, it is preferable to add a slurry in which particles are dispersed in ethylene glycol to a polycondensation reaction kettle so as to have a predetermined particle concentration to perform a polycondensation reaction.

  To reduce the amount of diethylene glycol in the polyester resin, shorten the polymerization time or limit the amount of antimony compound, germanium compound, titanium compound, etc. used as a polymerization catalyst, and combine liquid phase polymerization and solid phase polymerization. Examples thereof include a method and a method of containing an alkali component, but are not particularly limited. For example, when the amount of DEG is adjusted by containing potassium hydroxide, the amount of DEG is 0.01 by adding 0.01 to 0.10 parts by weight with respect to 100 parts by weight of dimethyl terephthalate. A polyethylene terephthalate resin having a weight percent of 1.5% or less can be obtained.

  Next, although the manufacturing method of the polyester film which concerns on this invention is demonstrated, it is not limited to this example. The dried polyester resin chip is supplied to an extruder, heated to a temperature equal to or higher than the melting point of the polyester resin, and melted. Next, the molten polyester resin is extruded as a molten sheet from a T-die having slit-like discharge ports, and is tightly solidified on a cooling roll to obtain a cast film (unoriented film (unstretched film)). In order to improve the adhesion between the molten sheet and the cooling roll, it is usually preferable to employ an electrostatic application adhesion method and / or a liquid surface application adhesion method.

  The cast film is further stretched biaxially.

  First, it is preferably stretched 2.3 to 7 times in the MD (film longitudinal) direction with a group of rolls heated to a glass transition temperature or higher, for example, 40 to 130 ° C., to obtain a uniaxially oriented film (uniaxially stretched film). .

Next, a coating liquid using a water-soluble and / or water-dispersible resin mainly composed of a polyurethane-based resin forming the anchor coat layer is applied to at least one surface of the uniaxially oriented film.
Next, the film is stretched 3 to 7 times at 45 to 130 ° C. in the TD (film width) direction. In addition, although the method of extending | stretching one direction in two steps or more can be used, it is preferable that the final draw ratio also falls in the said range also in that case. The cast film can be simultaneously biaxially stretched so that the area magnification is 6 to 30 times. Here, the area ratio means a value obtained by multiplying the MD stretch ratio by the TD stretch ratio. In this case, it is preferable to apply the coating liquid for forming the easy-adhesion layer before simultaneous biaxial stretching (that is, to apply to a cast film).

  Thereby, the biaxially oriented polyester film for vapor deposition (biaxially stretched film) of the present invention is obtained.

  Further, the film thus obtained may be subsequently heat-treated in-line and / or offline. Furthermore, you may extend | stretch in MD and / or TD direction again before or after performing heat processing as needed. The heat treatment temperature is 180 to 225 ° C, preferably 190 to 215 ° C, and the heat treatment time is usually 1 second to 5 minutes. The heat shrinkage characteristics can be adjusted under these heat treatment conditions. In addition, the cooling rate of the film after heat treatment also affects the heat shrink characteristics. For example, after the heat treatment, the heat shrinkage stress can be adjusted by providing the film with rapid cooling or slow cooling, or by providing an intermediate cooling zone. Further, in particular, in order to impart specific heat shrinkage characteristics, relaxation may be performed in the MD direction and / or TD direction during the heat treatment or in the subsequent slow cooling zone.

  Further, the biaxially oriented polyester film for vapor deposition of the present invention is also one of preferred usage modes in which a layer made of metal and / or metal oxide is laminated on an anchor layer and used as a gas barrier film for packaging. Examples of metals or metal oxides include magnesium, calcium, barium, group 4, titanium, zirconium, group 13, aluminum, indium, group 14, silicon, germanium, tin, and oxides thereof, which are group 2 of the periodic table. Can be mentioned. Among these, aluminum, silicon and oxides thereof are particularly preferable. These metals and oxides thereof may be combined to form a layer made of metal and / or metal oxide.

  As a method for laminating layers made of such metal and / or metal oxide, it can be formed by vapor deposition, sputtering, ion plating, plasma vapor deposition (CVD), or the like. However, in view of productivity, the vacuum deposition method is the best at present. As the heating means of the vacuum deposition apparatus by the vacuum deposition method, an electron beam heating method, a resistance heating method and an induction heating method are preferable. The thickness of the layer made of metal and / or metal oxide is generally preferably in the range of 2 to 300 nm, more preferably in the range of 3 to 100 nm, and still more preferably in the range of 5 to 50 nm. It is a range. If the film thickness exceeds 300 nm, the flexibility (flexibility) of the vapor-deposited thin film is reduced, and cracks or pinholes may occur in the thin film due to external forces such as bending and pulling after film formation (in post-processing steps, etc.) Gas barrier properties may be significantly impaired. Further, not only the transparency is lowered and the color is deteriorated, but also the productivity is remarkably lowered. On the other hand, when the film thickness is less than 2 nm, it is difficult to obtain a uniform film with good transparency, the film thickness may not be sufficient, and the gas barrier function may not be sufficiently exhibited.

  The biaxially oriented polyester film for vapor deposition and gas barrier film of the present invention are suitably used for packaging materials and industrial materials such as foods, pharmaceuticals and electronic parts. In particular, a film having low oxygen permeability and water vapor permeability and excellent water-resistant adhesion is preferably used for food and pharmaceutical packaging materials in order to prevent deterioration of the contents. Axial oriented polyester films and gas barrier films are useful.

Next, an Example is given and the biaxially-oriented polyester film for vapor deposition and gas barrier film of this invention are demonstrated concretely. In the examples, “parts” means “parts by weight” unless otherwise noted.
<Evaluation method of characteristics>
The characteristic evaluation method used in the present invention is as follows.

(1) Oxygen permeability (O2TR)
The oxygen permeability of the gas barrier film is 23 ° C. and the humidity is 0% RH. The oxygen permeability measuring device (model name “Oxytran” (registered trademark) (“OXTRAN” 2 / 20)) and measured based on the method B (isobaric method) described in JIS K7126 (2000 version). Moreover, the measurement was performed twice and the average value of the two measured values was used as the value of oxygen permeability in each of the examples and the comparative examples. About each Example and the comparative example, the result of having performed with two test pieces was made into the value of oxygen permeability.

(2) Water vapor transmission rate (MVTR)
Under the conditions of a gas barrier film having a water vapor transmission rate of 40 ° C. and a humidity of 90% RH, a water vapor transmission rate measuring device (model name, “Permatran” (registered trademark) W3 / 31) was used and measured based on the method B (infrared sensor method) described in JIS K7129 (2000 version). Moreover, the measurement was performed twice and the average value of the two measured values was used as the value of the water vapor transmission rate in each example and comparative example. About each Example and the comparative example, the result performed with two test pieces was made into the value of the water-vapor-permeation rate.

(3) The mass of 10 rectangular biaxially oriented polyester films for vapor deposition cut into a film thickness of 300 × 200 mm was measured, and the specific gravity of the film was set to 1.4 × 10 −3 (g / mm 3). The film thickness was determined as the mass average thickness by the formula:
T = W / (1.4 × 10−3 × 300 × 200 × 10)
However, T: Film thickness (mm), W: Mass of 10 films (g).

(4) Aluminum oxide was vapor-deposited on the anchor coat layer side of the biaxially oriented polyester film for water-resistant adhesion vapor deposition with a continuous vacuum vapor deposition machine so as to have a vapor deposition layer thickness of 15 nm to obtain a gas barrier film. An unstretched polypropylene film (CPP) using a polyurethane adhesive (AD503 / CAT-10 = 20 parts by weight / 1 part by weight, solvent: ethyl acetate 20 parts by weight, manufactured by Toyo Morton Co., Ltd.) on the vapor deposition layer side of the gas barrier film. ) (Toray Synthetic Film Co., Ltd. T3501, 50 μm) pasted together, left standing at 40 ° C. for 48 hours, cut into strips of length 150 mm × width 15 mm, and the gas barrier film and CPP were folded at 90 ° CPP and gas barrier film are gripped so that the release port is wetted with water droplets, and a wet 90 ° peel test is performed at 25 ° C. using an Instron type tensile tester (Tensilon UCT-100 manufactured by Orientec Co., Ltd.). Pulling in the direction of the arrow in FIG. 1 at a peeling rate (CHS) of 300 mm / min in an atmosphere of% RH It was of measurement. The average value of the strength between the measurement lengths of 50 mm and 100 mm was defined as the water-resistant adhesion.

(5) Micro endothermic peak (Tmeta) before crystal melting
In accordance with JIS K7122 (1999), measurement was performed using a differential scanning calorimeter (TA Instruments, Q100), and TA Instruments Universal Analysis 2000 was used for data analysis. A sample in which 10 mg of a polyester film was sealed in an aluminum sample pan was used, and the endothermic peak temperature when the temperature was raised from 30 ° C. to 300 ° C. at 20 ° C./min was defined as the melting point (crystal melting point). When a plurality of endothermic peaks existed, the peak temperature of the endothermic peak on the highest temperature side was taken as the melting point. A minute endothermic peak (peak temperature) having an endothermic amount of 0.2 to 5.0 J / g existing in a temperature range below the melting point was read and used as a minute endothermic peak (Tmeta) before crystal melting.

  In the method of reading the graph of the minute endothermic peak, first, a straight line is drawn with the value of 150 ° C. and the value of 170 ° C., and the area on the endothermic side of the graph curve is obtained. Similarly, 155 ° C and 175 ° C, 160 ° C and 180 ° C, 165 ° C and 185 ° C, 170 ° C and 190 ° C, 175 ° C and 195 ° C, 180 ° C and 200 ° C, 185 ° C and 205 ° C, 190 ° C and 210 ° C, The area is also obtained for 14 points of 195 ° C. and 215 ° C., 200 ° C. and 220 ° C., 205 ° C. and 225 ° C., 210 ° C. and 230 ° C., 215 ° C. and 235 ° C., 220 ° C. and 240 ° C. Since the endothermic amount of the minute peak is usually 0.2 to 5.0 J / g, only data having an area of 0.2 J / g or more and 5.0 J / g or less is handled as effective data. Of the total 15 pieces of area data, the peak temperature of the endothermic peak in the temperature region of the data that is effective data and indicates the largest area is defined as Tmeta. If there is no valid data, Tmeta is assumed to be none. An example chart is shown in FIG.

(6) Flatness The film was cut into A2 plates, and the film was spread and placed on a horizontal plate. One thread was stretched in a sufficiently long straight state on the top of the film (20 cm above the film surface). The yarn is stretched so as to be a straight line connecting the midpoint of one short side of the film to the midpoint of the other short side when the film is viewed from directly above. While observing the reflected image of the yarn reflected on the film, the viewing angle is changed to observe how the reflected image of the yarn passes through the entire film surface. The flatness was evaluated based on the degree of occurrence of the curved state exhibited by the reflected yarn. The evaluation criteria were as follows.

  Those having two or less curved portions on the entire surface were evaluated as “good” and indicated by “◯” in the table described later. In addition, a sample having three or less curved portions on the entire surface was evaluated as “slightly defective” and indicated by “Δ” in the table. In addition, a sample having four or more curved portions on the entire surface was evaluated as “defective” and indicated by “x” in the table.

[Coating solution adjustment]
(Coating solution 1)
429.1 parts of 1,3-xylylene diisocyanate, 35.4 parts of dimethylolpropionic acid, 61.5 parts of ethylene glycol and 140 parts of acetonitrile as a solvent were mixed and reacted at a temperature of 70 ° C. for 3 hours in a nitrogen atmosphere. A carboxylic acid group-containing polyurethane prepolymer solution was obtained. The carboxylic acid group-containing polyurethane prepolymer solution was then neutralized with 24.0 parts of triethylamine at a temperature of 50 ° C. 267.9 parts of this polyurethane prepolymer solution is dispersed in 750 parts of water with a homodisper and subjected to chain extension reaction with 35.7 parts of 2-[(2-aminoethyl) amino] ethanol to distill off acetonitrile. As a result, an aqueous dispersion of polyurethane resin 1 having a solid content of 25% by weight was obtained. 35 parts of water and 5 parts of methanol were added as dilution solvents to the aqueous dispersion 1 (10 parts) of the polyurethane resin thus obtained, and stirred for 30 minutes to obtain a coating liquid 1 having a solid content concentration of 5%. It was.

(Coating liquid 2-6)
Coating solutions 2 to 6 were prepared in the same manner as the coating solution 1 except that the reaction was carried out according to the formulation shown in Table 1.
Table 1 shows the formulation of coating liquids 1-6.
In the coating liquid 6, since a water dispersion was not obtained at the stage of dispersing with a homodisper, the preparation was interrupted.

The abbreviations and product names in Table 1 are shown below.
H6XDI: 1,3-bis (isocyanatomethyl) cyclohexane (hydrogenated xylylene diisocyanate)
XDI: 1,3-xylylene diisocyanate EG: ethylene glycol DEG: diethylene glycol OG: 1,8-octanediol
DMPA: dimethylolpropionic acid TEA: triethylamine AN: acetonitrile HDI: hexamethylene diisocyanate.

[Production of polyester]
A polyester resin as a thermoplastic resin constituting the base film was prepared as follows.

(1) To a mixture of 100 parts by weight of polyester resin dimethyl terephthalate and 61 parts by weight of ethylene glycol, 0.04 parts by weight of magnesium acetate and 0.02 parts by weight of antimony trioxide are added, and the temperature is gradually raised. Finally, transesterification is carried out while distilling methanol at 220 ° C. Next, 0.020 part by weight of an 85% aqueous solution of phosphoric acid is added to the transesterification reaction product, and then transferred to a polycondensation reaction kettle. Further, the reaction system was gradually depressurized while being heated, and a polycondensation reaction was performed at 290 ° C. under a reduced pressure of 1 hPa by a conventional method. The amount of diethylene glycol was 1.2% by weight and the intrinsic viscosity was 0.65. A polyethylene terephthalate resin (hereinafter sometimes referred to as “PET”) in which 95 mol% or more of the component is made of terephthalic acid and 95 mol% or more of the glycol component is made of ethylene glycol was prepared.

(2) Particle master When producing the polyester of (1) above, an ethylene glycol slurry of agglomerated silica particles having an average particle size of 2.4 μm is added after the transesterification reaction, and then a polycondensation reaction is carried out to obtain a particle concentration of 2 mass% A particle master was obtained.

  Next, the present invention will be described based on examples, but is not necessarily limited thereto.

Example 1
Polyethylene terephthalate resin and particle master were mixed at a mass ratio of 98: 2.
The mixture of polyethylene terephthalate resin and particle master is vacuum dried, then supplied to an extruder, melt extruded at 280 ° C., filtered through an 8 μm cut stainless steel fiber sintered filter (FSS), and then sheet-shaped from a T-shaped die. This was cooled and solidified on a cooling drum having a surface temperature of 25 ° C. by an electrostatic contact method. The unstretched (unoriented) PET film thus obtained was heated to 105 ° C. for 2 seconds and then stretched 3.7 times at 115 ° C. in the MD direction to obtain a uniaxially oriented film. In order to form an anchor coat layer on one side of the uniaxially oriented film, corona discharge treatment was performed in air. Subsequently, the coating liquid 1 was apply | coated to the electric discharge process surface side with the rod coater. The coating thickness was set to 0.1 μm after completion of oriented crystal of the polyester film, that is, after heat treatment.

  This uniaxially oriented film was preheated at 105 ° C. for 2 seconds and then stretched 3.7 times in the TD direction while being heated to 115 ° C. This film was introduced into hot air at 183 ° C., heat-treated for 2 seconds without relaxing in the MD direction and TD direction, and then relaxed at 170 ° C. to 2.4% of the film width after TD stretching in the width direction. And cooled. After finally cooling to room temperature, the surface opposite to the anchor coat layer was subjected to corona discharge treatment with a treatment strength of 20 W · min / m 2, and this was guided to a winder and wound up to obtain a mill roll. Thus, a biaxially oriented polyester film for vapor deposition having a thickness of 12 μm and finally provided with an anchor coat layer having a thickness of 0.1 μm was obtained.

  Next, aluminum oxide was deposited on the anchor coat layer side of the polyester film with a continuous vacuum deposition machine to a deposition layer thickness of 15 nm to obtain a gas barrier film.

(Example 2)
The heat treatment temperature was 193 ° C., and other conditions were the same as in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

Example 3
The heat treatment temperature was set to 203 ° C., and other conditions were the same as those in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

Example 4
The heat treatment temperature was 213 ° C., and other conditions were the same as in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

(Example 5)
The heat treatment temperature was 223 ° C., and other conditions were the same as in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

(Example 6)
The coating liquid was used as the coating liquid 2, and the other conditions were the same as those in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

(Example 7)
The coating liquid was used as the coating liquid 3, and other conditions were the same as those in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

(Comparative Example 1)
The heat treatment temperature was 228 ° C., and other conditions were the same as those in Example 1, and a biaxially oriented polyester film for vapor deposition having a thickness of 12 μm was obtained.

(Comparative Example 2)
The coating liquid was used as the coating liquid 4, and other conditions were the same as those in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

(Comparative Example 3)
The coating liquid was used as the coating liquid 5 and other conditions were the same as those in Example 1, and a biaxially oriented polyester film for vapor deposition having a thickness of 12 μm was obtained.

(Comparative Example 4)
The heat treatment temperature was 178 ° C., and other conditions were the same as those in Example 1, and a 12 μm thick biaxially oriented polyester film for vapor deposition was obtained.

  The characteristics of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 2.

The abbreviations and product names in Table 2 are shown below.
H6XDI: 1,3-bis (isocyanatomethyl) cyclohexane (hydrogenated xylylene diisocyanate)
XDI: 1,3-xylylene diisocyanate EG: ethylene glycol DEG: diethylene glycol OG: 1,8-octanediol
DMPA: dimethylolpropionic acid TEA: triethylamine AN: acetonitrile HDI: hexamethylene diisocyanate.

  The biaxially oriented polyester film for vapor deposition and gas barrier film of the present invention are useful because they can be applied to various barrier films for packaging such as gas barrier films used for food packaging.

1: CPP film 2: polyurethane adhesive 3: gas barrier film 4: melting point peak 5: minute endothermic peak (Tmeta) before crystal melting

Claims (5)

A layer made of a metal and / or a metal oxide is formed on the anchor coat layer of a biaxially oriented polyester film for vapor deposition having an anchor coat layer made of polyurethane-based resin (A) on at least one side of the polyester film. A laminated gas barrier film,
There is a minute endothermic peak before crystal melting obtained by differential scanning calorimetry measurement of the biaxially oriented polyester film for vapor deposition at 180 ° C. or more and 220 ° C. or less,
The polyurethane resin (A) is a resin comprising a polyisocyanate component (A1) and a polyol component (A2),
The polyisocyanate component (A1) contains an araliphatic diisocyanate (A1A) and / or an alicyclic diisocyanate (A1B),
The polyol component (A2) includes at least a polyhydroxyalkanoic acid (A2C), and further includes an alkane polyol having 2 to 6 carbon atoms (A2A) and / or a polyoxyalkylene glycol having 2 to 6 carbon atoms (A2B),
Ri der waterproof adhesive force 1N / 15 mm or more 4.3 N / 15 mm or less between the anchor coat layer and the metal and / or metal oxide layer,
The oxygen transmission rate at a temperature of 23 ° C. and a humidity of 0% RH is 0.5 cc / m ² . day. water vapor permeability at a temperature of 40 ° C. and a humidity of 90% RH is 0.6 g / m ² . A gas barrier film which is not more than day . The gas barrier film according to claim 1, wherein the polyisocyanate component (A1) contains xylylene diisocyanate (A1a1) and / or hydrogenated xylylene diisocyanate (A1b1). The gas barrier film according to claim 1 or 2, wherein the polyol component (A2) contains ethylene glycol (A2a1) and / or diethylene glycol (A2b1). The gas barrier film according to any one of claims 1 to 3, which is used for packaging materials. After extruding a polyester resin as a molten sheet and solidifying it tightly on a cooling roll to obtain an unstretched film, after stretching 2.3 to 7 times in the MD (film longitudinal) direction at 40 to 130 ° C. to obtain a uniaxially oriented film A coating liquid comprising a water-soluble and / or water-dispersible resin mainly composed of the polyurethane resin (A) for forming the anchor coat layer is applied to at least one surface of the uniaxially oriented film, and the TD (film width) direction is applied. It is made of a metal and / or a metal oxide on an anchor coat layer of a biaxially oriented polyester film for vapor deposition obtained by stretching 3 to 7 times at 45 to 130 ° C and performing a heat treatment temperature at 180 to 225 ° C. A method for producing a gas barrier film obtained by laminating layers, wherein the polyurethane resin (A) comprises a polyisocyanate component (A1) and a polyol. Wherein the polyisocyanate component (A1) contains an araliphatic diisocyanate (A1A) and / or an alicyclic diisocyanate (A1B), and the polyol component (A2) contains at least include polyhydroxyalkanoate (A2C), further, according to claim 1 comprising an alkane polyol having 2 to 6 carbon atoms (A2A) and / or polyoxyalkylene glycols having 2 to 6 carbon atoms (A2B) Of manufacturing a gas barrier film.

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