JP2014073598A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film having a high gas barriering capacity and an excellent repeated reproducibility of the gas barriering capacity.SOLUTION: The provided gas barrier film is obtained by laminating, in proper order, the following [A] layer 2 and [B] layer 3 on at least one surface of a biaxially oriented polyester film 1 satisfying specified requisites: [A] layer: a cross-linked resin layer having a pencil hardness of H or higher and a surface free energy of 45 mN/m or below; [B] layer: a silicon-containing inorganic layer having a thickness of 10-1000 nm.

Description

  TECHNICAL FIELD The present invention relates to a gas barrier film used for food and pharmaceutical packaging applications requiring high gas barrier properties, and for electronic member applications such as solar cells, electronic paper, and organic electroluminescence (EL) displays.

  Physical vapor deposition methods such as vacuum deposition, sputtering, ion plating, etc. using inorganic materials (including inorganic oxides) such as aluminum oxide, silicon oxide, and magnesium oxide on the surface of the biaxially oriented polyester film ( PVD method) or chemical vapor deposition method (CVD method) such as plasma chemical vapor deposition method, thermal chemical vapor deposition method, photochemical vapor deposition method, etc. The gas barrier film thus formed is used as a packaging material for foods and pharmaceuticals and the like for electronic devices such as flat-screen TVs and solar cells that require blocking of various gases such as water vapor and oxygen.

  As a gas barrier property improving technique, for example, a gas containing an organic silicon compound vapor and oxygen is used to form a silicon oxide as a main component on a substrate by a plasma CVD method, and at least one kind of carbon, hydrogen, silicon and oxygen. A method of improving gas barrier properties while maintaining transparency by using a compound that has been contained is used (Patent Document 1). In addition, as a gas barrier property improving technique other than a film forming method such as a plasma CVD method, the purpose is a smooth base material or a surface smoothing with reduced protrusions and irregularities that cause generation of pinholes and cracks that deteriorate the gas barrier property. A base material provided with an anchor coat layer is used (Patent Document 2).

JP-A-8-142252 (Claims) JP 2002-113826 A (Claims)

  However, in the method of forming a gas barrier layer mainly composed of silicon oxide by the plasma CVD method, the surface of the substrate is affected by plasma emission heat, ion, radical collision, etc. The film quality of the formed gas barrier layer is different, and there is a problem that a stable gas barrier property cannot be obtained.

  On the other hand, the method using a smooth substrate or a substrate with an anchor coat for the purpose of smoothing the surface of the substrate that forms the gas barrier layer improves the reproducibility of gas barrier properties by preventing the occurrence of pinholes and cracks. However, since the film quality of the formed gas barrier layer is not improved, the performance has not been dramatically improved.

  In view of the background of such conventional technology, the present invention is intended to provide a gas barrier film that can dramatically improve gas barrier properties and develop stable gas barrier properties without selecting the type of base material. .

The present invention employs the following means in order to solve such problems. That is,
(1) A gas barrier film in which the following [A] layer and [B] layer are laminated in this order on at least one surface of a biaxially oriented polyester film satisfying any of the following [1] to [7].
[A] layer: a crosslinked resin layer having a pencil hardness of H or more and a surface free energy of 45 mN / m or less [B] layer: a silicon-containing inorganic layer having a thickness of 10 to 1000 nm [1] containing an ultraviolet absorber and having a wavelength The transmittance at 380 nm is 5% or less. [2] The amount of oligomer deposited on the surface on which the [A] layer is laminated after heat treatment at 180 ° C. for 30 minutes is 3.0 mg / m ² or less. [3] Length 5 mm The number of scratches with a maximum depth of 0.5 μm or more is 70 / m ² or less. [4] A polyester film having an easy-adhesion layer ([C] layer) on at least one surface, and the layer thickness of the [C] layer is 50. In the state where the [C] layer and the [A] layer are laminated in this order, the undulation amplitude of the spectral reflectance at the measurement wavelength of 400 to 600 nm on the [A] layer side is 2.0% or less [5] ] Film longitudinal direction at 190 ° C The elongation in the width direction is 180% or more, and the surface orientation coefficient (fn) on both surfaces of the polyester film is 0.14 or less. [6] Aging for 36 hours in an environment of temperature 120 ° C. and humidity 100%. Later elongation retention is 40-100%
[7] The linear expansion coefficient α, which is the average of the linear expansion coefficient (α-MD) of MD from 50 ° C. to 150 ° C. and the linear expansion coefficient (α-TD) of TD, is 22 ppm / ° C. or less. The layer is composed of a composition containing a zinc compound and a silicon oxide. (3) The [B] layer is one of the following [B1] layer or [B2] layer: B1] layer: a layer composed of a coexisting phase of zinc oxide, silicon dioxide and aluminum oxide [B2] layer: a layer composed of a coexisting phase of zinc sulfide and silicon dioxide (4) The [B] layer is a [B1] layer, The [B1] layer has a zinc (Zn) atom concentration of 20 to 40 atom%, a silicon (Si) atom concentration of 5 to 20 atom%, and an aluminum (Al) atom concentration of 0.5 as measured by ICP emission spectroscopy. ˜5 atom%, oxygen (O) atom concentration is 35 to 70 atom% (5) The [B] layer is a [B2] layer, and the [B2] layer has a molar fraction of zinc sulfide to the total of zinc sulfide and silicon dioxide of 0.7 to (6) The average surface roughness Ra of the [A] layer is 1 nm or less. (7) The average surface roughness Ra of the [B] layer is 1. (8) a transparent conductive layer is provided between the surface of the [B] layer or the biaxially oriented polyester film and the [A] layer. (9) the transparent conductive layer is indium tin oxide. Including (ITO), zinc oxide (ZnO), aluminum-containing zinc oxide (Al / ZnO), gallium-containing zinc oxide (Ga / ZnO), metal nanowires, or carbon nanotubes (10) (1) to (1) 9) And a preferred embodiment the display element with a gas-barrier film of any of the solar cell (11) (1) to (9) having a gas barrier film.

  A gas barrier film having a high gas barrier property against oxygen gas, water vapor and the like can be provided.

It is sectional drawing which showed an example of the gas barrier film of this invention. It is the schematic which shows typically the winding-type sputtering apparatus for manufacturing the gas barrier film of this invention. It is a schematic sectional drawing of the roll extending | stretching apparatus which concerns on one embodiment of this invention. It is an expansion schematic sectional drawing of the extending part between rolls in FIG. It is the wavelength / reflectance graph which showed the waviness amplitude of the reflectance of the hard coat film.

  The inventors have made extensive studies for the purpose of obtaining a gas barrier film having a good gas barrier property, and on at least one surface of the biaxially oriented polyester film, a crosslinked resin layer having a specific pencil hardness and surface free energy and a specific When the silicon-containing inorganic layer having a thickness is arranged in this order, it has been found that the above-mentioned problems can be solved all at once.

FIG. 1 is a cross-sectional view showing an example of the gas barrier film of the present invention. As shown in FIG. 1, the gas barrier film of the present invention has a cross-linked resin layer having a pencil hardness of H or more and a surface free energy of 45 mN / m or less as a [A] layer on the surface of a biaxially oriented polyester film. ] As a layer, a silicon-containing inorganic layer having a thickness of 10 to 1000 nm is laminated in this order.
[Biaxially oriented polyester film]
The polyester film of the present invention is formed into a film using a polyester resin.

  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 preferably 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 preferably 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 to contain a particle | grain with an average particle diameter of 0.01-5 micrometers from a viewpoint of workability, such as barrier property after vapor deposition, handleability, and a lamination and printing. The particles may be known particles for film addition, and for example, internal particles, inorganic particles, and organic particles are preferable.

  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.

  As a form of the biaxially oriented polyester film, a single layer film or a film formed by two or more layers, for example, a co-extrusion method may be used. The surface of the biaxially oriented polyester film on the side where the cross-linked resin layer and the silicon-containing inorganic layer are formed has a corona treatment, an ion bombardment treatment, a solvent treatment, a roughening treatment, and an organic or inorganic material to improve adhesion. Alternatively, a pretreatment such as an anchor coat layer forming treatment composed of a mixture thereof may be performed. In addition, a coating layer of an organic material, an inorganic material, or a mixture thereof may be applied to the opposite surface on the side on which the cross-linked resin layer and the gas barrier layer are formed for the purpose of improving the slipping property when winding the film. .

  The thickness of the biaxially oriented polyester film used in the present invention is not particularly limited, but is preferably 500 μm or less from the viewpoint of ensuring flexibility, and is preferably 5 μm or more from the viewpoint of securing strength against tension and impact. Furthermore, the lower limit is more preferably 10 μm or more and the upper limit is more preferably 200 μm or less because of the ease of film processing and handling.

The biaxially oriented polyester film used in the present invention needs to satisfy one of the following [1] to [7]. When the biaxially oriented polyester film used in the present invention satisfies any of the following [1] to [7], a film suitable for various display applications, solar cell applications, flexible device substrate applications, and the like is obtained.
[1] Contains an ultraviolet absorber and has a transmittance of 5% or less at a wavelength of 380 nm. [2] The amount of oligomer deposited on the surface on which the [A] layer is laminated after heat treatment at 180 ° C. for 30 minutes is 3 0.03 mg / m2 or less [3] 70 / m2 or less scratches having a length of 5 mm or more and a maximum depth of 0.5 μm or more [4] A polyester film having an easy-adhesion layer ([C] layer) on at least one side. The thickness of the [C] layer is 50 to 150 nm, and the [C] layer and the [A] layer are laminated in this order, and the spectral reflectance at the measurement wavelength of 400 to 600 nm on the [A] layer side is Waviness amplitude is 2.0% or less [5] The elongation in the film longitudinal direction and the width direction at 190 ° C. is 180% or more, and the plane orientation coefficient (fn) on both surfaces of the polyester film is 0.14 or less. [6] Warm 120 ° C., elongation retention ratio after the 36 hour aging treatment at 100% of the environment humidity is 40 to 100%
[7] The linear expansion coefficient α, which is the average of the linear expansion coefficient (α-MD) of MD from 50 ° C. to 150 ° C. and the linear expansion coefficient (α-TD) of TD, is 22 ppm / ° C. or less.

  The biaxially oriented polyester film used in the present invention preferably contains [1] a UV absorber and has a transmittance of 5% or less at a wavelength of 380 nm because it can be suitably used for various displays. More preferably, the transmittance at a wavelength of 380 nm is 3% or less, and most preferably, the transmittance at a wavelength of 380 nm is 1% or less. This applies to a display member, particularly an electronic paper member, and the transmittance at 380 nm is defined in the above range from the viewpoint of the ultraviolet protection function of other materials and other compounds. By controlling the properties, it can be suitably used as various display members such as liquid crystal displays, electronic paper, organic EL displays, and projection television members, particularly as plasma display members.

  In order to make the transmittance at a wavelength of 380 nm within the above-mentioned preferable range, it can be achieved by appropriately adjusting the type and content of the ultraviolet absorber contained in the biaxially oriented polyester film. Preferred examples of the ultraviolet absorber include salicylic acid compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, benzoxazinone compounds, and cyclic imino ester compounds. These compounds can be used alone or in combination of two or more. In addition, stabilizers such as HALS and antioxidants can be used in combination, and it is particularly preferable to use a phosphorus-based antioxidant in combination. Examples of the benzotriazole-based compound include 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol and 2- (2H-benzotriazole-2). -Yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4-methylphenol, 2- (2H-benzotriazol-2-yl) ) -4,6-di-t-butylphenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t-amylphenol, 2- (2H-benzotriazol-2-yl) -4 -T-butylphenol, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ' It can be exemplified 5'-di -t- butyl-phenyl) -5-chloro-benzotriazole, or the like.

  Examples of the benzophenone compounds include 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4 ′. -Tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and the like can be mentioned.

  Examples of the benzoxazinone compounds include 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2- (p-benzoylphenyl) -3,1-benzoxazin-4-one, 2- ( 2-naphthyl) -3,1-benzoxazin-4-one, 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2 '-(2,6-naphthylene) Bis (3,1-benzoxazin-4-one) and the like can be exemplified.

  When the biaxially oriented polyester film used in the present invention satisfies [2] the amount of oligomer deposited on the surface on which the [A] layer is laminated after heat treatment at 180 ° C. for 30 minutes, the gas barrier is 3.0 mg / m 2 or less. This is preferable because the property is improved. More preferably, it is 2.0 mg / m 2 or less, and most preferably 1.0 mg / m 2 or less. When the oligomer precipitation amount exceeds 3.0 mg / m 2, the gas barrier property is deteriorated. If oligomers are deposited on the biaxially oriented polyester film before laminating the gas barrier layer, the surface smoothness is impaired and the gas barrier layer is defective, so that the gas barrier property is deteriorated. Further, when the oligomer is deposited after the gas barrier layer is laminated, the gas barrier layer is pushed up to become a convex shape, stress is applied to the gas barrier layer, cracks are generated, and the gas barrier property is deteriorated. The method for bringing the oligomer precipitation amount into the above preferred range is not particularly limited, but the oligomer contained in the polyester resin used for producing the biaxially oriented polyester film should be 0.6 wt% or less, or It is preferable to provide an oligomer precipitation preventing layer on the axially oriented polyester film.

  Examples of the method for setting the amount of oligomer contained in the polyester resin to 0.6 wt% or less include a heat treatment method for specifically explaining the polyester obtained by the polycondensation reaction.

  The apparatus for performing the heat treatment is not particularly limited, such as a rotary drier or a fixed tank drier having a stirrer, but a rotary drier is suitable in terms of equipment reliability.

  The difference obtained by subtracting the intrinsic viscosity after the heat treatment from the intrinsic viscosity before the heat treatment is preferably in the range of -0.10 to 0.10 dl / g. By setting the difference in intrinsic viscosity to be −0.10 dl / g or more, the intrinsic viscosity is suitable for molding, and particularly suitable for maintaining the strength of the film. On the other hand, by making the difference in intrinsic viscosity smaller than 0.10 dl / g, it is possible to suppress an increase in the filtration pressure during extrusion molding, and it is possible to perform higher-performance filtration on the molded product, and to reduce defects due to foreign matters. Furthermore, setting the difference in intrinsic viscosity before and after heat treatment within the above range is used as an application that does not require heat treatment with a conventional general grade without providing a special grade as a polyester used for heat treatment. Since a part of the varieties can be used as they are, the economic effect is great, such as eliminating the need to install new stockpiling facilities and transfer facilities, or reducing losses that occur when changing varieties.

  As the conditions for the heat treatment of the present invention, the polyester obtained by the above-mentioned conventionally known method is heated at a temperature of 190 to 240 ° C, preferably 210 to 235 ° C, more preferably 220 to 230 ° C. By setting the temperature to 190 ° C. or higher, the cyclic trimer-based oligomer can be efficiently reduced, and by setting the temperature to 240 ° C. or lower, it is possible to avoid melting and fusing part of the polyester. This is preferable.

  The pressure at this time is in the range of 960 to 1160 hPa, preferably 980 to 1130 hPa, and more preferably 990 to 1100 hPa. By setting the pressure to 960 hPa or more, ethylene glycol is released from the polyester to increase the intrinsic viscosity, and it is possible to suppress an increase in the filtration pressure in the extrusion process at the time of molding. On the other hand, by setting the pressure to 1160 hPa or less, This is preferable in that it prevents retention of acetaldehyde and the like generated inside, suppresses a decrease in intrinsic viscosity due to thermal decomposition of polyester, and maintains the strength of the molded product.

  The heat treatment time is in the range of 0.5 to 60 hours, preferably 10 to 50 hours, and more preferably 15 to 40 hours. By setting the treatment time to 0.5 hours or longer, oligomers mainly composed of cyclic trimers can be stably reduced. On the other hand, it is preferable that the processing time is 60 hours or less to suppress deterioration of quality such as color tone and improve productivity.

  Furthermore, kneading a phosphate ester compound having no hydroxyl group using the polyester composition obtained by the above heat treatment suppresses the regeneration of the oligomer during extrusion molding, and has an intrinsic viscosity suitable as a molded body. A polyester composition can be obtained economically.

  It is preferable that the phosphorus compound kneaded with the polyester of the present invention is a phosphate ester compound that does not contain a hydroxyl group. For example, phosphoric acid system such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, phosphorous acid system such as trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethylphosphine oxide, triethylphosphine oxide, Examples include phosphine oxides such as triphenylphosphine oxide, and phosphines such as triethylphosphine, phenylphosphine, diphenylphosphine, and triphenylphosphine, and any one or two of these are preferable. More preferably, triethylphosphonoacetate is preferable because it has excellent stability to the catalyst and heat, less corrosion of the apparatus, etc., low volatility and stable addition amount. When the phosphate compound to be added has a hydroxyl group, a large amount of foreign matter due to peeling of dirt from the barrel in the kneading apparatus or a foreign matter presumed to be a combination with the metal compound contained in the polyester composition is a problem. .

  A specific method for kneading the polyester of the present invention and a phosphate ester compound having no hydroxyl group is not particularly limited, and a known method can be used. However, it is preferable to knead and add them using a vent type extruder. . The method of kneading with a vent-type extruder is not particularly limited, but it is preferable to use a normal vent-type single-screw or twin-screw extruder.

  The kneading temperature is not less than the melting point of the polyester, the residence time is within 2 hours, preferably 1 minute to 1 hour, and the vent has a vacuum of 13330 Pa or less to remove decomposition gas components and low-volatile components and to suppress polyester degradation. , Preferably 1333 Pa or less, more preferably 266 Pa or less. Further, the method for supplying the phosphate ester compound and the polyester to the extruder is not particularly limited, but the phosphate ester compound not containing a hydroxyl group and the polyester may be mixed and supplied in advance. You may supply separately the phosphate ester compound and polyester which do not contain. In that case, it is preferable to supply the phosphoric acid ester compound which does not contain a hydroxyl group in the form of a solution or slurry appropriately mixed with water or a solvent such as alcohols.

  Although the compounding quantity of the phosphate ester compound of this invention is not specifically limited, It is 30-10000 ppm with respect to a polyester composition as a phosphorus element, Preferably it is 50-8000 ppm. If the amount of phosphorus element is 30 ppm or more, it is effective in suppressing the formation of oligomers. If it is 10000 ppm or less, the effect on the generation of foreign matters or the suppression of foaming during high temperature residence of the polyester composition is remarkable.

  Although it does not specifically limit as a method of providing an oligomer precipitation prevention layer, It is preferable to have a coating film layer containing a water-dispersible acrylic resin. This is because oligomer precipitation is easily blocked by the difference in surface energy between the acrylic resin coating layer and the film. Examples of the water-dispersible acrylic resin include acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-methylolacrylamide, N-butoxyacrylamide, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, and 12 to 25 carbon atoms. Examples include, but are not limited to, copolymers of monomers such as alkyl acrylate having an alkyl group in the side chain. In these water-dispersed acrylic resins, the average emulsion particle size is preferably 50 to 200 nm, and it is preferable to use one having a distribution as uniform as possible. In order to impart higher oligomer precipitation preventing properties, it is preferable to add a component having an oligomer precipitation preventing function to the coating layer. Examples of the component having an oligomer precipitation preventing function include, but are not limited to, a long-chain alkyl acrylate, a fluorine acrylate, a silicone compound, and a polyolefin compound. Since these components have a larger surface energy difference from the film than the water-dispersed acrylic resin, higher oligomer precipitation preventing properties can be obtained.

The biaxially oriented polyester film used in the present invention can be preferably used as a display member when [3] scratches having a length of 5 mm or more and a maximum depth of 0.5 μm or more satisfy 70 / m ² or less. More preferably, it is 50 or less / m ² , most preferably 30 / m ² or less. If the number of scratches having a length of 5 mm or more and a maximum depth of 0.5 μm or more exceeds 70 / m 2, the quality as a display member becomes insufficient and cannot be used as a display member. In order to make the number of scratches within the above preferable range, it is important that the film does not slip on the roll and does not stick to the roll. By setting the number of scratches within the above preferred range, it can be suitably used as a surface member for a display such as a liquid crystal display, electronic paper, or organic EL display.

  The method for preventing the film from slipping on the roll is not particularly limited, but it is preferable to perform a tension cut by niping the nip rolls 20 and 20 'between the low speed roll 19 and the high speed roll 19' as shown in FIG. .

  In addition, if the roll is in contact with the roll when the actual drawing process occurs, the film surface will be scratched, so the actual drawing process will be heated between the non-contact rolls above the glass transition temperature and stretched. It is preferable to make it occur. Therefore, it is preferable that preheating temperature shall be below the glass transition temperature of the thermoplastic resin which comprises a film. However, since efficient preheating cannot be performed at a very low temperature, the temperature should be high to some extent. Moreover, even if it is below a glass transition temperature, when the film surface adheres to a low-speed roll and a film peels from a roll, a fine crack may be generated. For this reason, the preheating temperature is preferably in the range of [film glass transition temperature −20] ° C. to [glass transition temperature of film] ° C., and more preferably [film glass transition temperature −15] ° C. The glass transition temperature of the film is in the range of −5] ° C. or lower.

  Furthermore, in order to heat the film to the glass transition temperature or higher in the actual stretching process, it is preferable to irradiate infrared rays from the upper and lower sides of the film with a condensing heater. A concentrating heater will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic cross-sectional view of the roll stretching apparatus 17 in the film longitudinal stretching method. The roll stretching device 17 arranges a low-speed roll 19 and a high-speed roll 19 ′ in order from the upstream side in the traveling direction (longitudinal direction) of the film 18, and a nip roll 20 for nipping the film 18 in each of the rolls 19 and 19 ′. , 20 ′, and a condensing heater and its casings 21, 21 ′ are disposed between the rolls 19, 19 ′ and above and below the film 18. FIG. 4 is an enlarged schematic cross-sectional view of a stretched portion between rolls. The irradiation length 22 in the longitudinal direction on the film surface by the infrared converging light irradiated from the condensing heater on the upper side of the film 18 in the inter-roll stretching section is the focal point 23 of the upper condensing heater, and the upper condensing heater. This is determined by the distance 24 from the lower end of the casing 21 to the upper surface of the film 18 before starting to stretch. Since these are in a similar relationship between two triangles with the focal point 23 as the apex, the irradiation length 22 and the irradiation width 25 at the lower end of the housing as the base, the irradiation length 22 is [irradiation length 22] = [irradiation width]. 25] × (1- [distance 24] / [distance from the lower end of the casing 21 to the focal point 23]). Similarly, the irradiation length 22 ′ in the longitudinal direction on the film surface by the infrared focused light irradiated from the condensing heater below the film 18 is the focal point 23 ′ of the lower condensing heater and the lower collecting light. It is determined by the distance 24 ′ from the upper end of the optical heater casing 21 ′ to the lower surface of the film 18 before starting to stretch. Since these are similar to two triangles with the focal point 23 ′ as the apex, the irradiation length 22 ′, and the irradiation width 25 ′ at the upper end of the housing as the base, the irradiation length 21 ′ is expressed as [irradiation length 21 ′. ] = [Irradiation width 25 ′] × (1- [distance 24 ′] / [distance from the upper end of the casing 21 ′ to the focal point 23 ′]). Further, there are portions where the irradiation lengths 22 and 22 'overlap on the film. In this case, the “overlapping portion” refers to a portion that overlaps with the light irradiated by the lower light collecting heater when the light irradiated on one surface of the film by the upper light collecting heater is projected onto the other surface as it is.

  The condensing heater used in the stretching method of the present invention has an infrared heater inside a casing made of metal or the like for the purpose of condensing or insulating, and the wavelength of the infrared heater ranges from a short wavelength to a medium wavelength (0 .8 μm or more and 3.0 μm or less) depending on the absorption efficiency and the required heat quantity of the thermoplastic resin constituting the film. Since light has energy corresponding to its frequency (reciprocal of wavelength), the shorter the wavelength, the higher the energy. Therefore, if the absorption efficiency of the thermoplastic resin does not change significantly in the range of the wavelength of 0.8 μm or more and 3.0 μm or less, it is possible to select a short wavelength (0.8 μm or more and 2.0 μm or less) to obtain higher energy Density can be obtained.

  The total output of the infrared heater is appropriately selected depending on the stretching conditions such as the infrared wavelength absorption efficiency of the thermoplastic resin constituting the film, the preheating temperature, and the stretching ratio. For example, an infrared heater having a wavelength of 1.1 μm (manufactured by Hibeck Co., Ltd.) is installed in the condensing heater housings on the upper and lower sides of the film, and the total electric energy of the infrared heater necessary for stretching the thermoplastic resin is as follows: It is preferably selected in the range of 10 W · h / kg to 23 W · h / kg, more preferably 12 W · h / kg to 21 W · h / kg, per unit weight (1 kg) of the plastic resin. If the total power of the infrared heater is less than 10 W · h / kg, the heat required for stretching will be insufficient unless the preheating temperature is set to the glass transition temperature or higher of the thermoplastic resin. Scratches such as scratches occur. If it is higher than 23 W · h / kg, even if it can be stretched, it will approach a so-called super-draw state that is substantially not accompanied by a change in molecular orientation, so that the required physical properties cannot be obtained.

  Each output of the upper and lower infrared heaters of the film is appropriately selected depending on the configuration of the roll stretching device, the film forming conditions, and the like. For example, when using a roll stretching apparatus composed of a pair of metal rolls provided with a nip roll coated with silicone rubber, as shown in FIGS. 3 and 4, the film surface on the lower side of the film is immediately before the stretch portion between the rolls. Therefore, the output of the infrared heater on the upper side of the film is preferably higher than the output of the infrared heater on the lower side of the film. Since the amount of heat received from both sides of the film becomes equal, uniform stretching can be achieved and thickness unevenness can be further reduced. Furthermore, since the transfer scratches of the surface shape by the roll are particularly likely to occur by the nip roll, in order to suppress the heating of the nip roll by the film transmitted light from the infrared heater on the lower side of the film, each output of the infrared heater on the upper side and the lower side of the film, It is preferable that the output of the infrared heater on the upper side of the film having the nip roll is 1.2 times to 3.0 times the output of the infrared heater on the lower side of the film. When the output ratio of the upper and lower infrared heaters of the film is larger than 3.0 times, the difference in the amount of heat received from both sides of the film becomes large, and thickness unevenness due to stretching tends to occur.

  The concentrating heater is arranged between the rolls and in the film width direction on the upper side and the lower side of the film, and the installation position in the film longitudinal direction is appropriately selected according to the longitudinal stretching process, but the actual stretching start position is set between the rolls. Therefore, the concentrating heater is preferably located near the center between the rolls. In order to stabilize the stretching start position, it is preferable to align the center positions in the film longitudinal direction of the condensing heaters on the upper and lower sides of the film.

  Further, when A is the distance from the lower end of the casing of the condensing heater on the upper side of the film to the film surface, and B is the distance from the upper end of the casing of the condensing heater on the lower side of the film to the film surface. Are preferably 10 mm or more and 30 mm or less, more preferably A and B are 10 mm or more and 30 mm or less and equal. When the distances A and B are narrower than 10 mm, the wrinkles and undulations occur in the longitudinal direction of the film, and the case and the film are easily brought into contact with each other. Resulting in. On the contrary, when the distances A and B are more than 30 mm, film scratches are caused by the film being adhered to the roll or thermally transferred due to heating of the peripheral roll or member due to leakage of infrared rays to the surroundings. End up. Moreover, when the distances A and B are equal, film heating by infrared rays from the upper side and the lower side of the film becomes uniform, and the stretching start position can be made more stable.

  The biaxially oriented polyester film used in the present invention is [4] a polyester film having an easy-adhesion layer ([C] layer) on at least one surface, and the [C] layer has a layer thickness of 50 to 150 nm, When the undulation amplitude of the spectral reflectance at the measurement wavelength of 400 to 600 nm on the [A] layer side is 2.0% or less with the [C] layer and the [A] layer laminated in this order, there is a difference in color unevenness. Since it becomes small, it is preferably used as a display member. More preferably, it is 1.5% or more. Within this range, the difference in color unevenness is small and inconspicuous, and the level is not detected by human eyes on the display.

  When the [A] layer is provided on the biaxially oriented polyester film, the spectral reflectance on the surface of the [A] layer is swelled. The average refractive index in the plane direction of the biaxially oriented polyester film is about 1.66, and the refractive index of the [A] layer is about 1.50. Therefore, the difference in refractive index between them is as large as about 0.16. The amplitude is large, and as a result, unevenness of reflectance, that is, color spots becomes remarkable. In particular, in the case of a three-wavelength fluorescent lamp that emits light in a specific narrow wavelength range, in such a narrow emission wavelength range, fluctuations in undulation caused by film thickness fluctuations in the [A] layer and deviations in the emission wavelength region increase, resulting in color spots. Is encouraged. Therefore, it is possible to reduce the amplitude of waviness by providing a laminated film having a refractive index intermediate between the refractive indexes of the biaxially oriented polyester film and the [A] layer, that is, the [C] layer. It is what. That is, the refractive index of the [C] layer is preferably 1.55 to 1.62, and more preferably 1.57 to 1.61. When it is smaller than 1.55, it becomes close to the refractive index of the [A] layer, and the refractive index difference from the biaxially oriented polyester film becomes large, so that the amplitude of waviness becomes large and the color spots become remarkable. On the contrary, when it is larger than 1.62, it becomes close to the refractive index of the biaxially oriented polyester film, and the difference in refractive index with the [A] layer becomes large, so that the amplitude of waviness becomes large and the color spots become remarkable. In addition, the thickness of the [C] layer is preferably 50 nm to 150 nm, more preferably 70 to 120 nm in order to allow a node with a large swell to exist in the visible light region (380 to 780 nm). If it is smaller than 50 nm, the node with a large swell shifts to the ultraviolet region, so the amplitude of the swell in the visible light region increases. If it is larger than 150 nm, the node with a large swell shifts to the infrared region. The amplitude of the undulation in the region becomes large, which is not preferable. In addition, a node with large undulation refers to a node in which the amplitude of undulation between the biaxially oriented polyester film and the [A] layer has wavelength dependency due to the presence of the [C] layer, and the amplitude of undulation is minimized.

  As a countermeasure against interference color unevenness, in order to set the refractive index of the [C] layer to 1.55 to 1.62, it is preferable to use polyester as the main resin of the [C] layer. Auxiliary acrylic resin or urethane resin may be used in combination. It is preferable that the ratio of a polyester resin is 50 weight% or more with respect to the whole [C] layer component. The polyester resin (a) for realizing a high refractive index is preferably a resin having a high glass transition point. The glass transition point Tg (a) is preferably 105 ° C. or higher and lower than 135 ° C., more preferably 110 ° C. or higher and lower than 130 ° C. If the glass transition point Tg (a) is less than 105 ° C., the refractive index cannot be increased, and if it is 135 ° C. or more, the amount of heat at the time of transverse stretching is lower than that, so that a coating film crack occurs, which is not preferable. As an example, an acid component using 2,6-naphthalenedicarboxylic acid is preferable.

  Moreover, it is also possible to use another kind of polyester resin (b) together for the purpose of water dispersibility, adhesiveness, moisture resistance and the like. The glass transition point Tg (b) of this polyester resin (b) is preferably 65 ° C. or higher and lower than 95 ° C., more preferably 70 ° C. or higher and lower than 90 ° C. As an example, it is preferable to use terephthalic acid as an acidic component in the polyester resin (b). The refractive index of the [C] layer depends on the mixing weight ratio of the polyester (a) to (b), but is preferably 2: 8 to 5: 5 in consideration of the refractive index, adhesiveness, and moisture resistance.

  The biaxially oriented polyester film used in the present invention has [5] elongation in the film longitudinal direction and width direction at 190 ° C. of 180% or more, and the plane orientation coefficient (fn) on both surfaces of the polyester film is 0. .14 or less is preferable because the moldability is improved. If the elongation of the polyester film is 180% or less, the gas barrier layer [B] is cracked by the stress that the film did not absorb at the same time as the tearing occurred during molding or the shape followability deteriorated, and the gas barrier layer cracked. Occurs, and the gas barrier property after molding is lowered, which is not preferable.

  When the plane orientation coefficient (fn) on both surfaces of the polyester film is 0.14 or less, the elongation in the film longitudinal direction and the width direction at 190 ° C. can be 180% or less. In order to make the plane orientation coefficient (fn) on both surfaces of the polyester film 0.14 or less, the polyester resin used can be adjusted according to the film forming conditions in addition to the composition described later. The preferred draw ratio is 3 to 4.2 times, more preferably 3 to 4 times, and most preferably 3 to 3.8 times in both the longitudinal direction and the width direction. The stretching speed is desirably 1,000% / min or more and 200,000% / min or less. Further, the preferred stretching temperature in the longitudinal direction is preferably 70 ° C. or higher and 110 ° C. or lower, more preferably 75 ° C. or higher and 100 ° C. or lower, and most preferably 80 ° C. or higher and 90 ° C. or lower. Moreover, as a preferable range of the extending | stretching temperature of the width direction, they are 80 degreeC or more and 120 degrees C or less, More preferably, they are 85 degreeC or more and 110 degrees C or less, Most preferably, they are 90 degreeC or more and 105 degrees C or less. The stretching method is not particularly limited, but after stretching in the longitudinal direction, stretching in the width direction, or stretching in the width direction and then stretching in the longitudinal direction, or the longitudinal direction of the film, Examples thereof include a simultaneous biaxial stretching method in which the width direction is stretched almost simultaneously. Also, the heat treatment conditions of the film after biaxial stretching are important. The heat treatment can be performed by a method such as heating on a heated roll in an oven. However, the heat treatment can be performed at a high temperature to relax the orientation and reduce the plane orientation coefficient.

  In the biaxially oriented polyester film used in the present invention, from the viewpoint of moldability, 50 to 90 mol% of the glycol residue component constituting the polyester resin constituting the film is ethylene glycol residue, 10 to 30 mol% is 1, It is preferable that 4-butanediol residue, 0.1-10 mol% is another glycol residue component. The content of 1,4-butanediol residue is more preferably 15 to 25 mol%, and the other glycol residue components are more preferably 1 to 5 mol%. Here, each glycol residue component may be present by being copolymerized in the polyester, but if copolymerization is performed, the melting point may be lowered and the heat resistance may be deteriorated. Several polyester resins each having a glycol residue component alone may be blended and contained in the film, or blending and copolymerization may be used in combination. Other glycol residue components are not particularly limited, but include diethylene glycol residues, 1,4-cyclohexanedimethanol residues, neopentyl glycol residues, 1,3-propanediol residues, etc. Can be preferably mentioned. In addition, a plurality of glycol residue components may be included as other glycol residue components.

  Furthermore, from the viewpoint of moldability, the polyester film of the present invention has 95 to 99 mol% of the dicarboxylic acid residue component constituting the polyester resin constituting the film, and 1 to 5 mol% of the other is 1 to 5 mol%. The dicarboxylic acid residue component is preferred. The other dicarboxylic acid residue component is more preferably 1 to 3 mol%. The dicarboxylic acid residue component may be a dicarboxylic acid as a starting component or a dicarboxylic acid ester derivative as a starting component. Here, the terephthalic acid residue and the other dicarboxylic acid residue may be present by being copolymerized in the polyester, but if the copolymerization is performed, the melting point is lowered. A method of existing in the resin and blending the polyester resin in the film is preferable. Moreover, you may use copolymerization and a blend together. Other dicarboxylic acid residue components are not particularly limited, but 2,6-naphthalenedicarboxylic acid residue, isophthalic acid residue, 5-sodium sulfoisophthalic acid residue, adipic acid residue, sebacic acid residue Preferred examples include groups, dimer acid residues, 1,4-cyclohexanedicarboxylic acid residues and the like.

  The biaxially oriented polyester film used in the present invention is [6] hydrolysis resistant when the elongation retention is 40 to 100% after aging treatment for 36 hours in an environment of a temperature of 120 ° C. and a humidity of 100%. It is preferable because it can be suitably used as a thermoplastic resin sheet for solar cells. The aging treatment for 36 hours in an environment of a temperature of 120 ° C. and a humidity of 100% is one of the tests for examining hydrolytic properties corresponding to 20 years in an outdoor exposure state as a thermoplastic resin sheet for solar cells. In order to satisfy the above elongation retention, the polyester resin layer having a number average molecular weight of 18500 to 40,000 is provided, this layer is disposed as the outermost layer, and the layer thickness is 7% or more of the total thickness of the sheet. It is preferable. When the film layer is less than 7%, deterioration proceeds from the outermost layer, and the elongation retention may be less than 40%.

  In the biaxially oriented polyester film used in the present invention, the polyester resin sheet preferably has a polyester resin layer having a number average molecular weight of 18500 or more in order to satisfy hydrolysis resistance. The upper limit is preferably as high as possible. However, when the number average molecular weight exceeds 40,000, extrusion is practically impossible, and in view of melt moldability and biaxial stretchability, a molecular weight of 35,000 or less is more preferable. That is, the number average molecular weight is 18500 to 40000, more preferably 19000 to 35000, and still more preferably 20000 to 30000. Here, the number average molecular weight in the biaxially oriented polyester film used in the present invention is measured by gel permeation chromatography (GPC) described later, and the number average molecular weight is an index of the degree of polymerization. When the number average molecular weight is within the range of the present invention, even when the hydrolysis reaction of the polyester resin proceeds, the degree of polymerization at the reaction start point is high, so that deterioration over time is superior to the number average molecular weight lower than 18500. Can be reduced.

  In order to adjust the number average molecular weight within the scope of the present invention, in the polymerization of the thermoplastic resin, the temperature for high polymerization is changed, for example, 190 to 230 ° C., the polymerization time is changed for 10 to 23 hours, and different number average molecular weights are obtained. A polymer can be obtained.

  In the present invention, the thickness of the polyester resin layer having a number average molecular weight of 18500 or more is preferably 7 to 100% of the thickness of the entire polyester resin sheet. Preferably, it is 10% or more. More preferably, it is 15% or more. That is, the entire sheet need not have a number average molecular weight of 18500 to 40,000, and a high molecular weight polyester resin having a thickness of 7% or more in the thickness direction of the film and having a number average molecular weight of 18500 to 40,000 may be formed. It is a polyester resin layer having a thickness of 7% or more, more preferably 10% or more of the thickness of all layers, and having a number average molecular weight in the range of 18500 to 40,000. It is preferable to form the surface layer most in order to impart hydrolysis resistance. Even if it is a high molecular weight polyester resin layer having a number average molecular weight of 18500-40000 with a thickness of less than 7% in the layer thickness direction, it is inferior in hydrolysis resistance, resulting in a decrease in strong elongation retention and rapid deterioration. If it is laminated with a thickness of 7% or more, it is advantageous for delamination from the lamination interface.

  Moreover, in order to effectively express the hydrolysis degradation prevention of the polyester resin sheet for solar cells of the present invention, it is more preferable that the polyester resin layers having an average molecular weight of 18500 to 40,000 are laminated on both sides.

  The method for controlling the number average molecular weight of the polyester resin of the present invention to 18500 to 40,000 is the above method, after polymerizing a normal polyester resin having a number average molecular weight of 18000 level, a temperature of 190 ° C. to less than the melting point of the polyester resin. Thus, a so-called solid-phase polymerization method in which heating is performed under reduced pressure or a flow of an inert gas such as nitrogen gas is preferable. This method can increase the number average molecular weight without increasing the terminal carboxyl group amount of the polyester resin.

  The biaxially oriented polyester film used in the present invention has an average linear expansion coefficient α of [7] MD linear expansion coefficient (α-MD) and TD linear expansion coefficient (α-TD) from 50 ° C. to 150 ° C. of 22 ppm. When the temperature is below / ° C., the thermal dimensional stability is good, and it is used in combination with other materials such as flexible device substrates processed at high temperatures and metals with low coefficient of linear expansion, such as lithium ion battery exterior materials It is preferably used in the following applications. When the linear expansion coefficient exceeds 22 ppm / ° C., the thermal dimensional stability of the film deteriorates and the workability deteriorates, which is not preferable.

  In order to make a linear expansion coefficient into the said preferable range, it is preferable to form into a film by the method of including following process (1) to (3) in this order.

(1) At a temperature T1n that satisfies the following formula (a) (n represents the n-th stage temperature in this step), the area magnification is 13.5 in the film longitudinal direction (MD) and the film width direction (TD). Step of biaxial stretching more than double Tg ≦ T1n ≦ Tg + 40 ° C. (a)
Tg: Glass transition temperature (° C.) of a polyester film obtained by differential scanning calorimetry
(2) Gripping both ends of the film in the width direction with respect to a straight line connecting both ends of the film in the width direction so that the shift in the center of the film in the gravitational direction is 1 mm or more and 50 mm or less. First heat treatment step of performing heat treatment at a heat treatment temperature Th1 satisfying Tm−90 ° C. ≦ Th1 ≦ Tm−45 ° C. (b)
Tm: Melting point (° C.) of a polyester film obtained by differential scanning calorimetry
(3) Under the condition of the heat treatment temperature Th2 satisfying the following formula (c), both MD and TD contract by 1% to 10% by the following processing method (3-1) or (3-2), Heat treatment step 150 ° C. ≦ Th 2 ≦ Th 1 (c)
(3-1) A film is cut into a sheet, and a batch process is applied in a state where both MD and TD are loosened in a rectangular metal frame. (3-2) A film installed between a winding roll and a winding roll Using an oven having an inlet and an outlet, continuous treatment is performed in a state in which the tension due to the dimensional change of the shrinkage of the MD of the film is relaxed due to the difference in speed between the winding roll and the winding roll.

  Although the polyester film obtained by the above manufacturing method has high heat-and-moisture resistance, it can also have favorable thermal dimensional stability, but the mechanism is considered as follows. In general, a polyester film obtained by biaxial stretching has a portion where the polyester is crystallized by orientation of molecular chains in the stretching direction (hereinafter referred to as an oriented crystal portion) and a portion crystallized without undergoing such orientation. (Hereinafter simply referred to as a crystal part) and an amorphous part exist. The amorphous part is considered to be in a state where the density is lower than that of the crystal part and the oriented crystal part and the average intermolecular distance is large.

  When the polyester film is exposed to a moist heat atmosphere, moisture (water vapor) enters the interior through the molecular chains of the amorphous part having a low density, and plasticizes the amorphous part to increase the mobility of the molecular chain. . Polyester has a carboxyl group terminal derived from its raw material, but moisture that has entered the inside hydrolyzes the amorphous part with relatively high molecular chain mobility using the proton at the carboxyl group terminal as a reaction catalyst. To do. By hydrolyzing in this way, the mobility of the molecular chain is further increased as the molecular weight is lowered in the amorphous part, and the crystallization of the polyester having the lowered molecular weight is advanced in the amorphous part. Thus, it is considered that the amorphous part having high toughness has a low molecular weight and is changed to the crystalline part. As a result, the embrittlement of the film progresses, and finally, even a slight impact results in a state of breaking.

  In the present invention, the ratio of the oriented crystal part having a higher density than that of the amorphous part can be increased by biaxial stretching and heat treatment in the steps (1) and (2), and moisture is contained in the film. Intrusion can be prevented. Moreover, when the ratio of the oriented crystal part is increased, the rigidity of the film is increased and the film is hardly thermally expanded. On the other hand, when the number of oriented crystal parts increases, the distortion of the amorphous part increases in the orientation direction of the oriented crystal parts. This strain is released when heat is applied to the film and the film shrinks irreversibly. In order to remove this distortion and suppress thermal shrinkage of the film, the treatment is performed in the step (3).

  By forming the film by the method including the steps (1) to (3) in this order, a polyester film having excellent heat and moisture resistance and good thermal dimensional stability can be obtained.

  The polyester resin used in the present invention contains phosphoric acid and an alkali metal phosphate, the alkali metal phosphate content is 0.5 mol / t or more, and the phosphoric acid content is relative to the alkali metal phosphate. The molar ratio is preferably 0.25 to 1.5 times. By including phosphoric acid and an alkali metal phosphate in the polyester resin used in the present invention, the initial number of carboxyl group terminals can be further reduced, so that hydrolysis reaction in a humid heat environment can be suppressed. Moreover, the neutralization of protons acting as a catalyst for the hydrolysis reaction at the end of the carboxyl group newly generated by the hydrolysis reaction can further suppress the hydrolysis reaction, thereby further suppressing the wet heat degradation of the polyester film. It becomes possible.

  The alkali metal phosphate used in the present invention is preferably represented by the following formula from the viewpoint of polymerization reactivity of the polyester resin and heat resistance during melt molding, and the alkali metal is sodium, and / or Alternatively, potassium is preferable from the viewpoint of polymerization reactivity, heat resistance, and heat and humidity resistance, and phosphoric acid and sodium and / or potassium metal salts are particularly preferable from the viewpoint of polymerization reactivity and heat and heat resistance.

PO _x H _y M _z (I)
(Here, x is an integer of 2 to 4, y is 1 or 2, z is 1 or 2, and M is an alkali metal.)
Specific examples of the alkali metal phosphate include alkali metal salts with compounds such as phosphoric acid, phosphorous acid, and hypophosphorous acid. As the alkali metal element, potassium and sodium are preferable from the point that precipitates due to catalyst residues are difficult to be generated. Specifically, potassium hydrogen phthalate, sodium dihydrogen citrate, disodium hydrogen citrate, citric acid Potassium dihydrogen, dipotassium citrate, sodium carbonate, sodium tartrate, potassium tartrate, sodium lactate, potassium lactate, sodium bicarbonate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, diphosphate phosphate Examples thereof include sodium hydrogen, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium hypophosphite, potassium hypophosphite, and sodium polyacrylate.

  The polyester resin used in the present invention preferably contains 0.5 mol / t or more of an alkali metal phosphate. More preferably, it is 1 mol / t or more. If the content of the alkali metal phosphate is less than 0.5 mol / t, the hydrolysis resistance is reduced, and the obtained polyester film may not have sufficient wet heat resistance. By setting the alkali metal phosphate of the biaxially oriented polyester film used in the present invention to 0.5 mol / t or more, it becomes possible to develop high moisture and heat resistance without deteriorating the quality of the film. In addition, the upper limit of the content of alkali metal phosphate is preferably 3 mol / t or less, more preferably 2.5 mol, from the viewpoint that excessive alkali metal phosphate may precipitate and become foreign matters. / T or less.

  The polyester resin used in the present invention preferably contains phosphoric acid in a molar ratio of 0.25 to 1.5 times with respect to the alkali metal phosphate. More preferably, it is 0.3 times or more and 1.25 times or less. If it is less than 0.25 times, the buffering action is difficult to be exhibited, the hydrolysis resistance is reduced, and the obtained polyester film may not have sufficient wet heat resistance. If the ratio exceeds 1.5 times, excess phosphoric acid reacts with the polyester during the polymerization reaction, and the phosphate ester skeleton is formed in the molecular chain, which accelerates the hydrolysis reaction. May decrease. By containing phosphoric acid in the polyester resin used in the present invention in a molar ratio of 0.25 times or more and 1.5 times or less with respect to the alkali metal phosphate, the obtained polyester film is made to exhibit high moisture and heat resistance. It becomes possible.

  Phosphoric acid and alkali metal phosphate may be added at the time of polymerization of the polyester resin or at the time of melt molding, but from the viewpoint of uniform dispersion of phosphoric acid and alkali metal phosphate in the film. It is preferable to add at the time of polymerization. In the case of adding at the time of polymerization, the addition time can be any time as long as it is from the end of the esterification reaction or transesterification reaction of the polyester resin to the beginning of the polycondensation reaction (inherent viscosity is less than 0.3). Can be added. As a method for adding phosphoric acid and alkali metal phosphate, either adding powder directly or adjusting and adding a solution dissolved in a diol component such as ethylene glycol may be used. It is preferably added as a solution dissolved in the diol component. In this case, when the solution concentration is diluted to 10% by mass or less and added, there is little adhesion of phosphoric acid and alkali metal phosphate to the vicinity of the addition port, and the error of the addition amount becomes small, and the reactivity This is preferable.

  In this invention, it is preferable that the polyester resin contains 0.005 mol% or more and 1.5 mol% or less of a component having three or more carboxylic acid groups and / or hydroxyl groups as copolymerization components with respect to all components. Here, the structural component having 3 or more carboxylic acid groups and / or hydroxyl groups refers to the following components.

  Examples of carboxylic acid components having three or more carboxylic acid groups include trifunctional aromatic carboxylic acid components such as trimesic acid, trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, and anthracentricarboxylic acid. Examples of aromatic carboxylic acid constituents include methanetricarboxylic acid, ethanetricarboxylic acid, propanetricarboxylic acid, butanetricarboxylic acid, and tetrafunctional aromatic carboxylic acid constituents such as benzenetetracarboxylic acid, benzophenonetetracarboxylic acid, naphthalenetetracarboxylic acid, Anthracene tetracarboxylic acid, berylene tetracarboxylic acid, etc. are tetrafunctional aliphatic carboxylic acid constituents such as ethanetetracarboxylic acid, ethylenetetracarboxylic acid, butanetetracarboxylic acid, cyclopentanetetracarboxylic acid, Hexanetetracarboxylic acid, adamantanetetracarboxylic acid, etc. are pentafunctional or higher functional aromatic carboxylic acid constituents such as benzenepentacarboxylic acid, benzenehexacarboxylic acid, naphthalenepentacarboxylic acid, naphthalenehexacarboxylic acid, naphthaleneheptacarboxylic acid, naphthalene. Octacarboxylic acid, anthracenepentacarboxylic acid, anthracenehexacarboxylic acid, anthraceneheptacarboxylic acid, anthraceneoctacarboxylic acid, etc. are penta- or higher functional aliphatic carboxylic acid constituents such as ethanepentacarboxylic acid, ethaneheptacarboxylic acid, butanepentapentane. Carboxylic acid, butaneheptacarboxylic acid, cyclopentanepentacarboxylic acid, cyclohexanepentacarboxylic acid, cyclohexanehexacarboxylic acid, adamantanepentacarboxylic acid, adama Tan hexacarboxylic acid and the, and the like These ester derivatives and acid anhydrides thereof as examples without limitation. Also preferred are those obtained by adding oxyacids such as l-lactide, d-lactide, hydroxybenzoic acid and the like, or a combination of a plurality of the oxyacids to the carboxy terminal of the carboxylic acid component. Used. Moreover, these may be used independently or may be used in multiple types as needed.

  Examples of components having 3 or more acid groups include trifunctional aromatic components such as trihydroxybenzene, trihydroxynaphthalene, trihydroxyanthracene, trihydroxychalcone, trihydroxyflavone, trihydroxycoumarin, and trifunctional fat. As an aliphatic alcohol constituent, glycerin, trimethylolpropane, propanetriol, a tetrafunctional aliphatic alcohol constituent, a compound such as pentaerythritol, and a constituent obtained by adding a diol to the hydroxyl terminal of the above compound are also preferable. Used. Moreover, these may be used independently or may be used in multiple types as needed.

  The component having three or more carboxylic acid groups and hydroxyl groups is an oxyacid having both a hydroxyl group and a carboxylic acid group in one molecule, and the total of the number of carboxylic acid groups and the number of hydroxyl groups is 3 or more. Specific examples include hydroxyisophthalic acid, hydroxyterephthalic acid, dihydroxyterephthalic acid, dihydroxyterephthalic acid, and the like.

  In addition, the above-described constituent components may be used alone, or a plurality of types may be used as necessary.

In this invention, it is preferable that content of this structural component is 0.005 mol% or more and 1.5 mol% or less. More preferably, they are 0.020 mol% or more and 1.0 mol% or less, More preferably, they are 0.025 mol% or more and 1.0 mol% or less, More preferably, they are 0.035 mol% or more and 0.5 mol% or less. If the content is 0.005 mol% or less, the effect of improving the moisture and heat resistance of the polyester film obtained by the production method of the present invention may be insufficient, and if it exceeds 1.5 mol%, the resin is gelled. In such a case, the gel exists as a foreign substance, and the biaxial stretchability when it is made into a film decreases or the film obtained by stretching has many foreign substance defects There is.
[Crosslinked resin layer]
Next, the [A] layer, which is a cross-linked resin layer having a pencil hardness of H or more and a surface free energy of 45 mN / m or less, will be described in detail.

  The thickness of the [A] layer used in the present invention is preferably 0.5 μm or more and 10 μm or less. If the thickness of the [A] layer is less than 0.5 μm, the film quality of the [B] layer is not uniform due to the unevenness of the biaxially oriented polyester film, and the gas barrier property may be deteriorated. When the thickness of the [A] layer is larger than 10 μm, the stress remaining in the [A] layer is increased, the biaxially oriented polyester film is warped, and cracks are generated in the [B] layer, so that the gas barrier property is lowered. There is a case. Therefore, the thickness of the [A] layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less from the viewpoint of ensuring flexibility. The thickness of the [A] layer can be measured from a cross-sectional observation image by a transmission electron microscope (TEM).

In the present invention, the pencil hardness of the [A] layer contributes to the effect that enables stable gas barrier properties to be exhibited. In addition, when forming a silicon-containing inorganic layer, it is possible to prevent damage caused by collision of plasma emission heat, ions, and radicals, resulting in stable gas barrier reproducibility. I guess it is. Therefore, the pencil hardness of the [A] layer is preferably H or higher, more preferably 2H or higher. On the other hand, when the upper limit of the pencil hardness of the [A] layer exceeds 5H, the flexibility is lowered, which may cause deterioration of gas barrier properties due to cracks in handling and post-processing after formation of the silicon-containing inorganic layer. Therefore, it is preferably 5H or less. (Pencil hardness is (soft) 10B-B, HB, F, H-9H (hard))
The pencil hardness test of the [A] layer in the present invention is carried out according to JIS K5600 (1999). The test is performed under a load of 0.5 kg using pencils having different hardnesses, and the determination is made based on the presence or absence of scratches. [A] When an inorganic layer or a resin layer is laminated on the surface of the layer [A], it is possible to evaluate the pencil hardness by performing a pencil hardness test after removing the layer by ion etching or chemical treatment as necessary. it can.

  Further, in the present invention, the contribution of the surface free energy of the [A] layer to the effect of dramatically improving the gas barrier property is that when the [B] layer is formed by setting the surface free energy to 45 mN / m or less. However, in the initial growth process of the silicon-containing inorganic compound, the atoms and particles that become the growth nuclei of the film are likely to move and diffuse, so the film quality near the [B] layer is densified. As a result, the entire layer is dense. It is estimated that the structure is improved and the permeation of oxygen and water vapor is suppressed. Therefore, the surface free energy of the [A] layer is preferably 45 mN / m or less, more preferably 40 mN / m or less.

  The surface free energy of the [A] layer in the present invention is obtained by using four types of measurement liquids (water, formamide, ethylene glycol, methylene iodide) with known components (dispersion force, polar force, hydrogen bonding force), The contact angle of each measurement solution is measured, and each component can be calculated using the following formula (1) introduced from the extended Fowkes formula and Young's formula.

  In addition, when the inorganic layer and the resin layer are laminated | stacked on the [A] layer surface, in the gas barrier film of this invention, the contact angle of said 4 types of measurement liquids is [A] layer thickness of [A] layer. It measures after grind | polishing by ion etching or a chemical | medical solution process in 30 to 70% of range. [A] The layer is located between the silicon-containing inorganic layer and the biaxially oriented polyester film layer. After removing one of the layers by ion etching or chemical treatment as necessary, the measurement method described above is used. By doing so, pencil hardness and surface free energy can be evaluated.

  When the average surface roughness Ra of the surface of the [A] layer in the present invention (the boundary surface with the [B] layer in the gas barrier film) is 1 nm or less, the occurrence of pinholes and cracks in the [B] layer to be laminated is further increased. Therefore, it is preferable because the reproducibility of gas barrier properties is improved. When the average surface roughness Ra of the surface of the [A] layer is larger than 1 nm, in the convex portion, pinholes are likely to occur after the lamination of the [B] layer, and cracks are generated in a portion with more unevenness. In some cases, the repetitive reproducibility of gas barrier properties may be deteriorated. Therefore, in the present invention, the average surface roughness Ra of the surface of the [A] layer is preferably 1 nm or less, from the viewpoint of suppressing the occurrence of fine defects such as microcracks during bending and improving flexibility. More preferably, it is 0.6 nm or less.

  The average surface roughness Ra of the [A] layer in the present invention can be measured using an atomic force microscope. In addition, when an inorganic layer or a resin layer is laminated on the surface of the [A] layer, the X-ray reflectivity method (“X-ray reflectivity introduction” (edited by Kenji Sakurai) Kodansha p.51-78, 2009) is used. The value obtained in this manner is defined as the average surface roughness Ra of the [A] layer.

  The material of the [A] layer used in the present invention is not particularly limited as long as the pencil hardness is H or more and the surface free energy is 45 mN / m or less, and various cross-linked resins can be used. The cross-linked resin here is defined as having one or more cross-linking points per 20000 number average molecular weight. Examples of the crosslinked resin that can be applied to the crosslinked resin layer in the present invention include acrylic, urethane, organic silicate compounds, silicone-based crosslinked resins, and the like. Among these, a thermosetting acrylic resin and an actinic ray curable acrylic resin are preferable from the viewpoint of durability of plasma heat and pencil hardness.

  Preferred examples of the thermosetting acrylic resin and the actinic ray curable acrylic resin include those containing a polyfunctional acrylate, an acrylic oligomer, and a reactive diluent, and other photoinitiators and photosensitizers as necessary. An agent, a thermal polymerization initiator or a modifier may be added.

  Examples of the polyfunctional acrylate suitably used for the acrylic resin described above include compounds having 3 or more (meth) acryloyloxy groups in one molecule. Examples of such compounds include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Examples include dipentaerythritol hexa (meth) acrylate and trimethylolpropane tri (meth) acrylate. These polyfunctional acrylates can be used alone or in combination of two or more. In the present invention, the polyfunctional acrylate may include a modified polymer of polyfunctional acrylate.

  The acrylic oligomer has a number average molecular weight of 100 to 5000 and has at least one reactive acrylic group bonded in the molecule. Examples of the skeleton include polyacrylic resins, polyester resins, polyurethane resins, polyepoxy resins, and polyether resins. The skeleton may be a rigid skeleton such as melamine or isocyanuric acid.

  The reactive diluent has a function of a solvent in the coating process as a coating medium, and has a group that itself reacts with a monofunctional or polyfunctional acrylic oligomer. It will be.

  In particular, in the case of cross-linking with ultraviolet rays, since light energy is small, a photopolymerization initiator and / or a photosensitizer should be added in order to convert the light energy and promote the reaction. Is preferred.

  The use ratio of the polyfunctional acrylate in the blending of the material of the [A] layer used in the present invention is preferably 20 to 90% by mass with respect to the total amount of the [A] layer, from the viewpoint of making the pencil hardness H or more. Preferably it is 40-70 mass%. When this ratio is greater than 90% by mass, the shrinkage of curing is large and the biaxially oriented polyester film may be warped. In such a case, cracks are generated in the silicon-containing inorganic layer, and the gas barrier property is deteriorated. May occur. Moreover, when the ratio of a monomer becomes smaller than 20 mass%, the adhesive strength of a base material and an [A] layer falls, and problems, such as peeling, may generate | occur | produce.

  As a method of crosslinking the [A] layer in the present invention, it is preferable to add a photopolymerization initiator when applying curing by light. Examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4,4. '-Bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoylfomate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2,2-dimethoxy -2-phenylacetophenone, carbonyl compounds such as 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfate De, tetramethyl thiuram disulfide, thioxanthone, 2 - chloro thioxanthone, 2 - sulfur compounds such as methyl thioxanthone, benzoyl peroxide, di - t - peroxide compounds such as butyl peroxide, and the like.

  The amount of the photopolymerization initiator used is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the polymerizable composition, and remains as an unreacted product during polymerization and does not affect the gas barrier property. 05 to 5 parts by weight are preferred.

  The coating liquid containing the resin forming the [A] cross-linked resin layer used in the present invention loses the effect of the present invention for the purpose of improving workability during coating and controlling the coating film thickness. In such a range, it is preferable to add an organic solvent. A preferred range for blending the organic solvent is 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 80% by mass or less.

  Examples of the organic solvent include alcohol solvents such as methanol, ethanol and isopropyl alcohol, acetate solvents such as methyl acetate, ethyl acetate and butyl acetate, ketone solvents such as acetone and methyl ethyl ketone, and aromatic solvents such as toluene. Etc. can be used. These solvents may be used alone or in combination of two or more.

  In addition, the coating liquid containing a resin that forms the crosslinked resin layer of the [A] layer used in the present invention includes inorganic substances such as silica, alumina, and zinc oxide for the purpose of improving adhesion with the [B] layer. It is preferable to blend particles. Among these, silica-based inorganic particles that strongly adhere to the silicon-containing inorganic layer are preferable, and silica-based inorganic particles obtained by hydrolysis with a silane compound or the like are more preferable. A preferred range for blending the inorganic particles is 0.1% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less.

  In the present invention, various additives can be blended as necessary within the range where the effects of the present invention are not impaired. For example, stabilizers such as antioxidants, light stabilizers, ultraviolet absorbers, surfactants, leveling agents, antistatic agents, and the like can be used.

  As a method of setting the surface free energy of the [A] layer used in the present invention to 45 mN / m or less, dimethylpolysiloxane, as long as the adhesion and gas barrier properties between the [A] layer and the [B] layer are not deteriorated, Examples thereof include a method of adding a silicone having a low surface tension such as methylphenylpolysiloxane, or a monomer having a long chain alkyl group such as n-stearyl acrylate which is lipophilic.

  [A] As a means for applying a coating liquid comprising a resin forming the layer, for example, a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a die coating method, a spray coating method, or the like can be used. Among these, a gravure coating method is preferable as a method suitable for coating of 0.5 μm or more and 10 μm or less, which is the thickness of the [A] layer in the present invention.

The active rays used when the [A] layer is crosslinked include ultraviolet rays, electron beams, radiation (α rays, β rays, γ rays), and ultraviolet rays are preferred as a practically simple method. The heat source used for crosslinking by heat includes a steam heater, an electric heater, an infrared heater and the like, and an infrared heater is preferable from the viewpoint of temperature control stability.
[Silicon-containing inorganic layer]
Next, the silicon-containing inorganic layer having a thickness of 10 to 1000 nm which is the [B] layer will be described in detail. In the present invention, the silicon-containing inorganic layer [B] has a thickness of 10 to 1000 nm, and is disposed on the cross-linked resin layer having a pencil hardness of H or more and a surface free energy of 45 mN / m or less as the [A] layer. .

  As a result of the study by the inventors, it was found that the gas barrier property can be dramatically improved by laminating the [B] layer on the [A] layer.

As a material suitably used for the [B] layer in the present invention, silicon dioxide having an amorphous and dense film quality and excellent gas barrier properties is preferable. “Silicon dioxide” may be abbreviated as “SiO ₂ ”. Also, silicon (SiO ₂₎ dioxide, the generation time of the condition, those slightly deviated from the composition ratio of silicon and oxygen on the left formula (SiO~SiO ₂₎ although it is possible to produce silicon dioxide or SiO ₂ It shall be written as

  By laminating the [B] layer on the [A] layer, the [A] layer is a cross-linked resin layer having a pencil hardness of H or more, so the heat resistance and thermal dimensionality of the biaxially oriented polyester film are improved. To do. Then, by forming a silicon dioxide layer on the [A] layer, when forming the silicon dioxide layer, compared to forming the silicon dioxide layer directly on the biaxially oriented polyester film, Since the biaxially oriented polyester film can be prevented from being damaged by the plasma ions and radicals, a stable and dense silicon dioxide layer can be formed. Furthermore, since the surface free energy of the [A] layer is in the range of 45 mN / m or less, the sputtered particles of the silicon dioxide layer on the surface of the biaxially oriented polyester film are more likely to diffuse, and the surface of the biaxially oriented polyester film is more than conventional. It is speculated that the gas barrier properties can be improved because the film quality in the vicinity becomes finer and denser.

  [B] If the layer contains silicon oxide, oxide, nitride, sulfide, or a mixture of elements such as Zn, Al, Ti, Zr, Sn, In, Nb, Mo, Ta, etc. May be included. For example, a layer comprising a coexisting phase of [B1] zinc oxide-silicon dioxide-aluminum oxide (hereinafter abbreviated as [B1] layer) or [B2] a coexisting phase of zinc sulfide and silicon dioxide is obtained as a high gas barrier property. A layer consisting of (hereinafter abbreviated as [B2] layer) is preferably used. Details of the [B1] layer and the [B2] layer will be described later.

  Further, on the [B] layer in the present invention, a hard coat layer for the purpose of improving scratch resistance may be formed within a range in which the gas barrier property is not deteriorated, or a film made of an organic polymer compound is laminated. It is good also as a laminated structure.

  The thickness of the [B] layer used in the present invention is preferably 10 nm or more and 1000 nm or less as the thickness of the layer exhibiting gas barrier properties. When the thickness of the layer is less than 10 nm, there may be a portion where the gas barrier property cannot be sufficiently secured, and there may be a problem that the gas barrier property varies in the biaxially oriented polyester film surface. In addition, when the thickness of the layer is greater than 1000 nm, the stress remaining in the layer increases, so that the [B] layer is liable to be cracked by bending or external impact, and the gas barrier property decreases with use. There is. Therefore, the thickness of the [B] layer is preferably 10 nm or more and 1000 nm or less, and more preferably 100 nm or more and 500 nm or less from the viewpoint of ensuring flexibility. [B] The thickness of the layer can usually be measured by cross-sectional observation with a transmission electron microscope (TEM).

  The average surface roughness Ra of the [B] layer used in the present invention is preferably 1.5 nm or less as the surface roughness that exhibits gas barrier properties. When the average surface roughness is larger than 1.5 nm, the uneven shape on the surface of the [B] layer becomes large, and a gap is formed between the sputtered particles to be laminated, so that the film quality is difficult to be dense and the film thickness is increased. However, the effect of improving the gas barrier property is difficult to obtain. Therefore, the average surface roughness Ra of the [B] layer is preferably 1.5 nm or less, and more preferably 0.8 nm or less.

  The average surface roughness Ra of the [B] layer in the present invention can be measured using an atomic force microscope. In addition, when the inorganic layer and the resin layer are laminated | stacked on the [B] layer surface, the value obtained using the X-ray reflectivity method (above) is made into the average surface roughness Ra of a [B] layer. .

  The method for forming the [B] layer is not particularly limited, and can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a CVD method, or the like. Among these methods, the sputtering method is preferable as a method for forming the [B] layer easily and inexpensively.

[Layer consisting of a coexisting phase of zinc oxide-silicon dioxide-aluminum oxide]
Next, as the [B1] layer suitably used as the silicon-containing inorganic layer in the present invention, a layer composed of a coexisting phase of zinc oxide-silicon dioxide-aluminum oxide will be described in detail. The “coexisting phase of zinc oxide-silicon dioxide-aluminum oxide” may be abbreviated as “ZnO—SiO ₂ —Al ₂ O ₃ ”. Also, silicon (SiO ₂₎ dioxide, the generation time of the condition, those slightly deviated from the composition ratio of silicon and oxygen on the left formula (SiO~SiO ₂₎ although it is possible to produce silicon dioxide or SiO ₂ It shall be written as Regarding the deviation of the composition ratio from the chemical formula, the same applies to zinc oxide and aluminum oxide, and zinc oxide or ZnO, aluminum oxide or Al ₂ , regardless of the composition ratio deviation depending on the conditions at the time of formation. It shall be written as O ₃ .

  The reason why the gas barrier property is improved by applying the [B1] layer in the gas barrier film of the present invention is that, in the coexisting phase of zinc oxide-silicon dioxide-aluminum oxide, the crystalline component contained in zinc oxide and silicon dioxide Presuming that by coexisting with the amorphous component, crystal growth of zinc oxide, which tends to generate microcrystals, is suppressed and the particle size is reduced, so that the layer is densified and the permeation of oxygen and water vapor is suppressed. Yes.

  In addition, the coexistence of aluminum oxide can suppress the crystal growth more than the coexistence of zinc oxide and silicon dioxide, so it is considered that the gas barrier property deterioration due to the generation of cracks can be suppressed. It is done.

  The composition of the [B1] layer can be measured by ICP emission spectroscopy as described later. The Zn atom concentration measured by ICP emission spectroscopy is 20 to 40 atom%, the Si atom concentration is 5 to 20 atom%, the Al atom concentration is 0.5 to 5 atom%, and the O atom concentration is 35 to 70 atom%. ,preferable. When the Zn atom concentration is higher than 40 atom% or the Si atom concentration is lower than 5 atom%, the oxide that suppresses the crystal growth of zinc oxide is insufficient, resulting in an increase in voids and defects, and sufficient gas barrier properties. It may not be obtained. When the Zn atom concentration is lower than 20 atom% or the Si atom concentration is higher than 20 atom%, the amorphous component of silicon dioxide inside the layer may increase and the flexibility of the layer may be lowered. Also, when the Al atom concentration is higher than 5 atom%, the affinity between zinc oxide and silicon dioxide becomes excessively high, and the pencil hardness of the film increases, and cracks are likely to occur due to heat and external stress. is there. When the Al atom concentration is less than 0.5 atom%, the affinity between zinc oxide and silicon dioxide becomes insufficient, and the bonding force between the particles forming the layer cannot be improved, so that the flexibility may be lowered. Further, when the O atom concentration is higher than 70 atom%, the amount of defects in the [A] layer increases, so that a predetermined gas barrier property may not be obtained. When the O atom concentration is less than 35 atom%, the oxidation state of zinc, silicon, and aluminum becomes insufficient, the crystal growth cannot be suppressed, and the particle diameter increases, so that the gas barrier property may be deteriorated. From this viewpoint, it is more preferable that the Zn atom concentration is 25 to 35 atom%, the Si atom concentration is 10 to 15 atom%, the Al atom concentration is 1 to 3 atom%, and the O atom concentration is 50 to 64 atom%.

  The component contained in the [B1] layer is not particularly limited as long as zinc oxide, silicon dioxide and aluminum oxide are in the above composition and are the main components. For example, Al, Ti, Zr, Sn, In, Nb, Mo, A metal oxide formed of Ta, Pd, or the like may be included. Here, the main component usually means 60% by mass or more of the composition of the [B1] layer, and preferably 80% by mass or more.

  The composition of the [B1] layer is formed with the same composition as the mixed sintered material used at the time of forming the layer. Therefore, by using a mixed sintered material having a composition that matches the composition of the target layer [B1 It is possible to adjust the composition of the layer.

The composition analysis of the [B1] layer uses ICP emission spectroscopy to quantitatively analyze each element of zinc, silicon, and aluminum, and determine the composition ratio of zinc oxide, silicon dioxide, aluminum oxide, and the inorganic oxide contained. I can know. The oxygen atoms are calculated on the assumption that zinc atoms, silicon atoms, and aluminum atoms exist as zinc oxide (ZnO), silicon dioxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ), respectively. The ICP emission spectroscopic analysis is an analysis method capable of simultaneously measuring multiple elements from an emission spectrum generated when a sample is introduced into a plasma light source unit together with argon gas, and can be applied to composition analysis. When an inorganic layer or a resin layer is laminated on the [B] layer, ICP emission spectroscopic analysis can be performed after removing the layer by ion etching or chemical treatment as necessary.

  The method for forming the [B1] layer on the biaxially oriented polyester film is not particularly limited, and uses a mixed sintered material of zinc oxide, silicon dioxide and aluminum oxide, vacuum deposition method, sputtering method, ion plating method. Etc. can be formed. When using a single material of zinc oxide, silicon dioxide, and aluminum oxide, form a film of zinc oxide, silicon dioxide, and aluminum oxide simultaneously from separate vapor deposition sources or sputter electrodes, and mix them to the desired composition. Can be formed. Among these methods, the [B1] layer forming method used in the present invention is more preferably a sputtering method using a mixed sintered material from the viewpoint of gas barrier properties and composition reproducibility of the formed layer.

[Layer consisting of a coexisting phase of zinc sulfide and silicon dioxide]
Next, the details of the layer made of a coexisting phase of zinc sulfide and silicon dioxide will be described as the [B2] layer. The “zinc sulfide-silicon dioxide coexisting phase” is sometimes abbreviated as “ZnS—SiO ₂ ”. Further, silicon dioxide (SiO _2), depending on the conditions at the time of generation, those slightly deviated from the composition ratio of silicon and oxygen on the left formula (SiO~SiO ₂₎ although it is possible to produce silicon dioxide or SiO Indicated as ₂ .

  The reason why the gas barrier property is improved by applying the [B2] layer in the gas barrier film of the present invention is that the crystalline component contained in the zinc sulfide and the amorphous component of silicon dioxide in the zinc sulfide-silicon dioxide coexisting phase. It is presumed that the crystal growth of zinc sulfide, which tends to generate microcrystals, is suppressed and the particle size is reduced, so that the layer is densified and the permeation of oxygen and water vapor is suppressed. In addition, the zinc sulfide-silicon dioxide coexisting phase containing zinc sulfide with suppressed crystal growth is more flexible than a layer formed only of inorganic oxides or metal oxides. Therefore, it is considered that the deterioration of the gas barrier property due to the generation of cracks could be suppressed by applying such a [B2] layer.

  The composition of the [B2] layer is preferably such that the molar fraction of zinc sulfide relative to the total of zinc sulfide and silicon dioxide is 0.7 to 0.9. If the molar fraction of zinc sulfide with respect to the total of zinc sulfide and silicon dioxide is greater than 0.9, there will be insufficient oxide that suppresses crystal growth of zinc sulfide, resulting in an increase in voids and defects, resulting in a predetermined gas barrier property. May not be obtained. Further, when the molar fraction of zinc sulfide with respect to the total of zinc sulfide and silicon dioxide is less than 0.7, the amorphous component of silicon dioxide inside the [B2] layer increases and the flexibility of the layer decreases, The flexibility of the gas barrier film with respect to mechanical bending may be reduced. More preferably, it is the range of 0.75-0.85.

  The components contained in the [B2] layer are not particularly limited as long as zinc sulfide and silicon dioxide are in the above composition and are the main components. For example, Al, Ti, Zr, Sn, In, Nb, Mo, Ta, Pd Or a metal oxide such as Here, the main component usually means 60% by mass or more of the composition of the [B2] layer, and preferably 80% by mass or more.

  Since the composition of the [B2] layer is formed with the same composition as the mixed sintered material used at the time of forming the layer, the composition of the [B2] layer can be changed by using a mixed sintered material having a composition suitable for the purpose. It is possible to adjust.

  In the composition analysis of the [B2] layer, first, the composition ratio of zinc and silicon is obtained by ICP emission spectroscopic analysis. Based on this value, each element is quantitatively analyzed by using Rutherford backscattering method, and zinc sulfide, silicon dioxide and The composition ratio of other inorganic oxides contained can be known. The ICP emission spectroscopic analysis is an analysis method capable of simultaneously measuring multiple elements from an emission spectrum generated when a sample is introduced into a plasma light source unit together with argon gas, and can be applied to composition analysis. In Rutherford backscattering method, a charged particle accelerated by a high voltage is irradiated on a sample, and the number of charged particles bounced from the sample and the element are identified and quantified from the energy, and the composition ratio of each element can be known. Since the [B2] layer is a composite layer of sulfide and oxide, analysis by Rutherford backscattering method capable of analyzing the composition ratio of sulfur and oxygen is performed. [B2] When an inorganic layer or a resin layer is laminated on the layer, the layer may be removed by ion etching or chemical treatment as necessary, and then analyzed by ICP emission spectroscopic analysis or Rutherford backscattering method. it can.

  The method for forming the [B2] layer on the transparent biaxially oriented polyester film is not particularly limited. By using a mixed sintered material of zinc sulfide and silicon dioxide, a vacuum deposition method, a sputtering method, an ion plating method, etc. Can be formed. When a single material of zinc sulfide and silicon dioxide is used, it can be formed by simultaneously forming films of zinc sulfide and silicon dioxide from different vapor deposition sources or sputtering electrodes, and mixing them to obtain a desired composition. Among these methods, the [B2] layer forming method used in the present invention is more preferably a sputtering method using a mixed sintered material from the viewpoint of gas barrier properties and composition reproducibility of the formed layer.

[Transparent conductive layer]
Since the gas barrier film of the present invention has excellent gas barrier properties such as oxygen and water vapor, it is mainly used for packaging materials such as foods and pharmaceuticals, display elements such as electronic paper and organic EL television, and electronic devices such as solar cells. It can be used as a member. That is, by providing a transparent conductive layer between the surface of the [B] layer or between the biaxially oriented polyester film and the [A] layer and sealing the display element and the electronic device, oxygen, water vapor from the outside High durability can be imparted with little change in electrical resistance due to.

  Examples of the transparent conductive layer used in the present invention include indium tin oxide (ITO), zinc oxide (ZnO), aluminum-containing zinc oxide (Al / ZnO), gallium-containing zinc oxide (Ga / ZnO), metal nanowires, It is preferable to include any of carbon nanotubes. As a thickness of a transparent conductive layer, the range of 0.1-500 nm is preferable, and 5-300 nm is more preferable as a range with favorable transparency.

  The methods for forming the transparent conductive layer include dry coating methods such as vacuum deposition, EB deposition, and sputtering deposition, casting, spin coating, dip coating, bar coating, spraying, blade coating, slit die coating, gravure coating, reverse coating, and screen. General methods such as wet coating methods such as printing, mold coating, printing transfer, and ink jet can be listed.

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

  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.

  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 3 to 7 times in the MD (film longitudinal) direction with a group of rolls heated to a glass transition temperature of the polyester resin or higher, for example, 70 to 130 ° C., to obtain a uniaxially oriented film (uniaxially stretched film). Next, the film is stretched 3 to 7 times at 70 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 used for this invention is obtained.

  Further, it is preferable that the film thus obtained is subsequently heat-set in-line and / or off-line. Furthermore, you may extend | stretch in MD and / or TD direction again before or after performing heat setting as needed. The heat setting temperature is 180 to 250 ° C., preferably 190 to 240 ° C., and the heat treatment time is usually 1 second to 5 minutes.

  Further, in this heat setting step, the heat shrinkage characteristics can be adjusted. The cooling rate of the film after heat setting also affects the heat shrinkage characteristics. For example, the heat shrinkage stress can be adjusted by rapidly or slowly cooling the film after heat setting or by providing an intermediate cooling zone. In particular, in order to give specific heat shrinkage characteristics, it is preferable to relax in the MD direction and / or the TD direction at the time of heat setting or in the subsequent cooling zone under the above-described conditions.

  The film can be coated as necessary. In the case of the present invention, the adhesiveness with the [A] layer can be improved by providing a coating layer on the film. As the coating solution, a solution which is dissolved in water, emulsified or suspended in view of explosion proof and environmental pollution is used. The coating layer may be applied to a biaxially stretched film after completion of crystal orientation, or may be stretched after being applied to a film before completion of crystal orientation, but the latter method is used in order to exhibit the effects of the present invention more remarkably. Is particularly preferred. The method of applying is not particularly limited, but it is preferable to apply using a roll coater, gravure coater, reverse coater, kiss coater, bar coater or the like. Moreover, you may corona-discharge-process in the air | atmosphere other various atmosphere before application | coating as needed before apply | coating.

  In the coating layer in the present invention, an antifoaming agent, a coating crosslinker, a thickener, an organic lubricant, inorganic particles, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, and a pigment are used as necessary. Etc. may be included.

Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited to the following examples. In the examples, “parts” means “parts by weight” unless otherwise noted.
[Evaluation method]
First, an evaluation method in each example and comparative example will be described. The number of evaluation n was n = 5 and the average value was obtained unless otherwise specified.

(1) Layer thickness Samples for cross-sectional observation were obtained by the FIB method using a microsampling system (Hitachi FB-2000A) (specifically, “Polymer Surface Processing” (by Satoshi Iwamori) p. 118-119). (Based on the method described in 1). Using a transmission electron microscope (H-9000UHRII manufactured by Hitachi), the cross section of the observation sample was observed at an acceleration voltage of 300 kV, and the thicknesses of the [A] layer and the [B] layer were measured. The interface of the substrate and the [B] layer, [A] layer and [B] layer was judged by a cross-sectional observation photograph using a transmission electron microscope.

(2) Pencil hardness test [A] The pencil hardness of the layer surface is set to n = 1 according to JIS K5600-5-4 (1999) using a pencil hardness tester HEIDON-14 (Shinto Kagaku Co., Ltd.). The pencil hardness was measured.

(3) Surface Free Energy [A] Four types of measurement liquids (water, formamide, ethylene glycol, methylene iodide) whose surface free energy and its components (dispersion force, polarity force, hydrogen bonding force) are known on the surface of the layer [A] The contact angle of each liquid on the laminated film was measured with a contact angle meter CA-D type (manufactured by Kyowa Interface Science Co., Ltd.) under the conditions of a temperature of 23 ° C. and a relative humidity of 65%. The average value of 5 pieces was used for the measurement. Each component was calculated from this value using the following formula (1) introduced from the extended Fowkes formula and Young's formula.

(4) Average surface roughness Ra
Using an atomic force microscope, the surface of the crosslinked resin layer as the [A] layer was measured under the following conditions.
System: NanoScopeIII / MMAFM (manufactured by Digital Instruments)
Scanner: AS-130 (J-Scanner)
Probe: NCH-W type, single crystal silicon (manufactured by Nanoworld)
Scanning mode: Tapping mode Scanning range: 10 μm × 10 μm
Scanning speed: 0.5Hz
Measurement environment: temperature 23 ° C., relative humidity 65%, in air.

(5) Water vapor transmission rate (g / (m ² · d))
Measurement was performed using a water vapor transmission rate measuring device (model name: DELTAPERRM (registered trademark)) manufactured by Technolox, UK, under conditions of a temperature of 40 ° C., a humidity of 90% RH, and a measurement area of 50 cm ² . . The number of samples was 2 samples per level, the number of measurements was 5 times for each sample, and the average value of 10 points obtained was the water vapor transmission rate (g / (m ² · d)).

(6) Composition of [B1] layer The composition analysis of the [B1] layer was performed by ICP emission spectroscopic analysis (manufactured by SII Nanotechnology Inc., SPS4000). The sample was thermally decomposed with nitric acid and sulfuric acid, heated and dissolved with dilute nitric acid, and filtered. The insoluble matter was ashed by heating, melted with sodium carbonate, dissolved with dilute nitric acid, and made up to a constant volume with the previous filtrate. About this solution, content of a zinc atom, a silicon atom, and an aluminum atom was measured, and it converted into atomic ratio. The oxygen atoms were calculated values assuming that zinc atoms, silicon atoms, and aluminum atoms exist as zinc oxide (ZnO), silicon dioxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ), respectively.

(7) Composition of [B2] layer The composition analysis of the [B2] layer was performed by ICP emission spectroscopic analysis (manufactured by SII Nanotechnology Inc., SPS4000). The sample was thermally decomposed with nitric acid and sulfuric acid, heated and dissolved with dilute nitric acid, and filtered. The insoluble matter was ashed by heating, melted with sodium carbonate, dissolved with dilute nitric acid, and made up to a constant volume with the previous filtrate. About this solution, content of a zinc atom and a silicon atom was measured. Next, based on this value, further using Rutherford backscattering method (AN-2500 manufactured by Nissin High Voltage Co., Ltd.), quantitative analysis of zinc atom, silicon atom, sulfur atom, oxygen atom and zinc sulfide The composition ratio of silicon dioxide was determined.

(8) Composition X-ray photoelectron spectroscopy (XPS method) of the [B3] layer was used to measure the atomic ratio (O / Al ratio) of oxygen atoms to aluminum atoms. The measurement conditions were as follows.
・ Device: Quantera SXM (manufactured by PHI)
Excitation X-ray: monochromic AlKα1,2
X-ray diameter 100 μm Photoelectron escape angle: 10 °

(9) Transmittance at a wavelength of 380 nm
The biaxially oriented polyester film before laminating the [A] layer and the [B] layer was placed on a spectrophotometer U-3410 (Hitachi Ltd.) with a φ60 integrating sphere 130-063 (Hitachi Ltd.) and 10 °. The transmittance at 380 nm was measured with the inclined spacer attached.

(10) Determination of oligomer precipitation amount The biaxially oriented polyester film before laminating the [A] layer and the [B] layer was heat-treated in an oven at 180 ° C. for 30 minutes. Thereafter, with the surface on which the [A] layer was laminated facing outward, a film was attached to a 50 mm × 50 mm surface of a 50 mm × 50 mm × 30 mm cuboid aluminum jig, and the end was bent and fixed along the jig. The jig was immersed in a dimethylformamide solvent for 3 minutes with the film side down to a depth of 5 mm to extract surface precipitated oligomers.
Next, as a standard solution, 11.2 mg of a polyethylene terephthalate cyclic oligomer (trimer purity 89%) was placed in a 100 mL volumetric flask and mixed with 1,1,1,3,3,3-hexafluoro-2-propanol / chloroform solvent. (= 1/1) After dissolving in 2 mL, the standard stock solution (trimer concentration 100 μg / mL) was diluted to 100 mL with chloroform. This solution was sequentially diluted with dimethylformamide to prepare standard solutions having trimer concentrations of 10 μg / mL, 1 μg / mL, and 0.1 μg / mL.
The surface oligomer extraction solvent and the standard solution were analyzed by high performance liquid chromatography (HPLC) under the following conditions, the amount of cyclic trimer was measured, and the amount of oligomer precipitation was determined.
Equipment: Shimadzu LC-10A
Column: Inertsil ODS-3
Mobile phase: acetonitrile / water = 70/30
Flow rate: 1.5 mL / min
Detector: UV242nm
Injection volume: 10 μL
(11) Measurement of film scratches Video light ("VL-G301" manufactured by LPL), which is a powerful light source, in a dark room with a biaxially oriented polyester film before laminating the [A] and [B] layers The scratches are detected by visually observing 10 m in the longitudinal direction using. The detected scratches were measured for length and depth under the following conditions using a non-contact optical interference type three-dimensional surface roughness meter (manufactured by ZYGO, New View 200).
・ Number of pixels: 320 × 240 pixels ・ Scanning speed: 2 μm / second ・ Magnification: 20 times ・ Measurement area: 0.352 mm × 0.264 mm
・ Correction: cylinder correction ・ Cutoff wavelength: 0.44 mm, 4.4 μm
-Filter trimming: ON
-Filter type: FFT FIXED
・ Filter: Band Reject
・ FDARes: High
(12) Biaxially oriented polyester before laminating the dried and solidified film of the resin used for the water-based coating applied to one or both sides of the refractive index biaxially oriented polyester film, or the [A] layer and the [B] layer For the film, the Abbe refractometer (Atago Co., Ltd. Abbe refractometer) was used as the light source sodium lamp (Na-D line), the mount solution was methylene iodide, 23 ° C., 65% relative humidity, The refractive index of the film (two directions orthogonal to each other, or the longitudinal direction and the width direction were measured, and the average value of the values) was measured.

(13) Amplitude of waviness of spectral reflectance at 400 to 600 nm after lamination of [A] layer [B] Using [A] layer laminated biaxially oriented polyester film before layer lamination, opposite to [A] layer A black glossy tape with a width of 50 mm (vinyl tape No. 200-50-21: black, manufactured by Yamato Co., Ltd.) was bonded to the surface of the surface so as not to bite the air bubbles, and then cut into about 4 cm square sample pieces. , A spectrophotometer (U3410, manufactured by Hitachi, Ltd.) with a φ60 integrating sphere (130-0632, manufactured by Hitachi, Ltd.) and a 10 ° tilt spacer, and [A] at an incident angle of 10 ° at a wavelength of 400 to 600 nm. The spectral reflectance on the layer side was measured. With respect to the line connecting the peaks of the undulations (mountain line) and the lines connecting the valleys of the undulations (valley line), each wavelength (11 locations, wavelengths are (400 + 20 × i (i = 0 to 0)) The difference (mountain line-valley line) in the place where the integer is 10) nm) was determined, and the average was taken as the undulation amplitude. FIG. 5 shows a measurement schematic diagram of the undulation amplitude.
In order to standardize the reflectance, an attached Al ₂ O ₃ plate was used as a standard reflecting plate.

(14) Evaluation of interference fringes Using a biaxially oriented polyester film obtained by laminating the [A] layer before laminating the [B] layer, a sample having a size of 10 cm × 10 cm was cut out, and on the opposite side of the [A] layer A black glossy tape (Yamato Co., Ltd., vinyl tape No. 200-50-21: black) was bonded so as not to bite the bubbles. Place this sample in a dark room 30 cm directly under a 3-wavelength fluorescent lamp (3-wave daylight white (F · L15EX-N15W) manufactured by Matsushita Electric Industrial Co., Ltd.), and visually observe the degree of interference fringes while changing the viewing angle. The following evaluation was performed. A practical level was marked as △, and a grade above ○ was marked as good.
◎: Interference fringes are almost invisible ○: Interference fringes are slightly visible ×: Interference fringes are strong (15) Plane orientation coefficient (fn)
The biaxially oriented polyester film before laminating the [A] layer and the [B] layer using sodium D-line (wavelength 589 nm) as a light source, methylene iodide as a mounting liquid, and using an Abbe refractometer at 25 ° C. MD, TD, and refractive indexes in the thickness direction (nMD, nTD, and nZD, respectively) were determined. The plane orientation coefficient (fn) was calculated from the obtained refractive index according to the following formula. In addition, the measurement evaluated by the average of the measured value in three arbitrary places.
fn = (nMD + nTD) / 2−nZD
(16) Breaking elongation at 190 ° C. The biaxially oriented polyester film before laminating the [A] layer and the [B] layer was cut into a short shape having a length of 150 mm × width of 10 mm in the longitudinal direction and the width direction, did. Using a tensile tester (Orientec Tensilon UCT-100), an initial tensile chuck distance was set to 50 mm, and a tensile speed was set to 300 mm / min. In the measurement, a film sample was set in a constant temperature layer set in advance to a temperature of 190 ° C., and a tensile test was performed after 90 seconds of preheating. The elongation at break in each direction was determined from the obtained load-strain curve. In addition, the measurement was performed 5 for each sample and each direction, and the evaluation was performed with an average value of 3 points excluding the calculated maximum value and the minimum value.

(17) Water vapor permeability after molding The gas barrier film after laminating the layers [A] and [B] is heated using a far infrared heater at 450 ° C. so that the surface temperature becomes 150 ° C. Vacuum / pressure forming (pressure: 0.2 MPa) was performed along a cylindrical mold (bottom diameter: 50 mm, height: 20 mm) at a mold temperature of 70 ° C. The cylindrical mold was vacuum-formed with the edge portion R being 2 mm. Next, sampling was performed with the center point of the bottom surface after molding as the center, and the water vapor transmission rate after molding was measured by the method described in (5) Water vapor transmission rate.

(18) Elongation retention rate The elongation at break of the biaxially oriented polyester film before laminating the [A] layer and the [B] layer is 1 cm × 20 cm based on ASTM-D882 (1999). And the elongation at break was measured when pulled at 5 cm between chucks and at a pulling speed of 300 mm / min. The measurement was performed on five samples, and the elongation at break was defined as the average value. In addition, the elongation retention is obtained by cutting a sample into the shape of a measurement piece (1 cm × 20 cm) and then treating with a pressure cooker manufactured by Tabai Espec Co., Ltd. for 36 hours under conditions of a temperature of 120 ° C. and a humidity of 100% RH. After the treatment, the breaking elongation of the treated sample was measured based on ASTM-D882 (1999), when the breaking elongation was 5 cm between chucks and pulled at a pulling speed of 300 mm / min. The measurement was performed on five samples, and the elongation at break was defined as the average value. Using the obtained breaking elongations E0 and E1, the breaking elongation retention was calculated according to the following formula.
・ Elongation at break (%) = E1 / E0 × 100
(19) Linear expansion coefficient (α)
Using a thermomechanical measuring device TMA / SS6100 (manufactured by Seiko Instruments Inc.) for a biaxially oriented polyester film before laminating the [A] layer and the [B] layer, a sample width of 4 mm and a sample length (distance between chucks) of 20 mm A load of 3 g was applied to the sample. The temperature was raised from room temperature to 170 ° C. at a rate of temperature rise of 10 ° C./min and held for 10 minutes. Thereafter, the temperature was lowered to 20 ° C. at 10 ° C./min. At that time, the coefficient of thermal expansion was determined from the following equation from the dimensional change from 150 ° C. to 50 ° C. in the temperature-decreasing portion. The thermal expansion coefficient was an average value of the thermal expansion coefficient in the film longitudinal direction and the thermal expansion coefficient in the width direction, and the n number was evaluated as 3.
Thermal expansion coefficient α (ppm / ° C.) = {(L150−L50) / L0} / ΔT × 1000000
L0: Length of film at 23 ° C. (mm)
L150: length of the film at 150 ° C. when the temperature is lowered (mm)
L50: Length of film (mm) at 50 ° C. when the temperature is lowered
ΔT: temperature change (150−50 = 100)
[Production of polyester]
A polyester resin as a thermoplastic resin constituting the biaxially oriented polyester film was prepared as follows.

(1) Polyester resin A
To a mixture of 100 parts by weight of dimethyl terephthalate and 61 parts by weight of ethylene glycol, 0.04 part by weight of magnesium acetate and 0.02 part by weight of antimony trioxide are added, and the temperature is gradually raised. 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 heated, and a polycondensation reaction was performed at 290 ° C. under a reduced pressure of 1 hPa. The carboxyl group concentration was 34 eq / t, the intrinsic viscosity was 0.65 dl / g, oligomer A polyester resin A having a content of 1.1 wt% and a diethylene glycol content of 2.0 wt% was obtained.

(2) Polyester resin B
Polyester resin A and 2,2′-p-phenylenebis (3,1-benzoxazin-4-one) as an ultraviolet absorber were added to a 2,2′-p-phenylenebis (3 1-benzoxazin-4-one) was compounded to 10% by weight. This was designated as polyester resin B.

(3) Polyester resin C
The polyester resin A was put into a 7.5 m ³ conical tumbler dryer for 3 tons, dried at 150 ° C. for 3 hours, introduced with nitrogen at 101 × 10 ³ Pa, and maintained at 101 × 10 ³ Pa. Flowing at a flow rate of 05 liters / hr · kg, heating at 225 ° C. for 25 hours, polyester resin C having a carboxyl group concentration of 36 eq / t, an intrinsic viscosity of 0.64, and an oligomer content of 0.30% by weight Obtained.

(4) Polyester resin D
A mixture of 100 parts by weight of terephthalic acid and 110 parts by weight of 1,4-butanediol was heated to 140 ° C. under a nitrogen atmosphere to obtain a homogeneous solution, and then 0.054 parts by weight of tetra-n-butyl orthotitanate. Then, 0.054 part by weight of monohydroxybutyltin oxide was added, and esterification reaction was performed by a conventional method. Next, 0.066 part by weight of tetra-n-butyl orthotitanate was added, and a polycondensation reaction was performed under reduced pressure to produce a polybutylene terephthalate resin having an intrinsic viscosity of 0.84. Thereafter, crystallization was performed at 140 ° C. in a nitrogen atmosphere, followed by solid state polymerization at 200 ° C. for 6 hours in a nitrogen atmosphere to obtain a polyester resin D having an intrinsic viscosity of 1.20.

(5) Polyester resin E
To a mixture of 100 parts by weight of dimethyl terephthalate, 70 parts by weight of ethylene glycol, and 7 parts by weight of 1,4-cyclohexanedimethanol, 0.04 part by weight of manganese acetate is added, and the temperature is gradually raised. The transesterification was performed while distilling methanol. Next, 0.045 parts by weight of 85% aqueous phosphoric acid solution and 0.01 parts by weight of germanium dioxide are added, and the temperature is gradually raised and reduced. Finally, the temperature is raised to 275 ° C. and 1 hPa, and the intrinsic viscosity is reduced. The polycondensation reaction was carried out until 0.67, and then discharged into a strand, cooled, and cut to obtain a polyethylene terephthalate resin copolymerized with 4 mol% of 1,4-cyclohexanedimethanol. The polymer was cut into cubes having a diameter of 3 mm, and solid phase polymerization was performed using a rotary vacuum polymerization apparatus under a reduced pressure of 1 hPa at 225 ° C. until the intrinsic viscosity was 0.8, whereby polyester resin E was obtained.

(6) Polyester resin F
Polyester resin A is placed in a rotary vacuum device (rotary vacuum dryer) having a high polymerization temperature of 190 to 230 ° C. and a vacuum degree of 0.5 mmHg, heated with stirring for 12 hours, and has an intrinsic viscosity of 0.66. A polyester resin F having an average molecular weight of 19,800 was obtained.

(7) Polyester resin G
Polyester resin A is placed in a rotary vacuum device (rotary vacuum dryer) having a high polymerization temperature of 190 to 230 ° C. and a vacuum degree of 0.5 mmHg, and heated with stirring for 16 hours. A polyester resin G having an average molecular weight of 27000 was obtained.

(8) Polyester resin H
Polyester resin A is placed in a rotary vacuum device (rotary vacuum dryer) having a high polymerization temperature of 190 to 230 ° C. and a vacuum degree of 0.5 mmHg, and heated with stirring for 20 hours. A polyester resin H having an average molecular weight of 35,000 was obtained.

(9) Polyester resin I
After melting 100 parts by weight of dimethyl terephthalate, 57.5 parts by weight of ethylene glycol, 0.06 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide in a nitrogen atmosphere at 150 ° C., the mixture is stirred for 3 hours up to 230 ° C. for 3 hours. The methanol is distilled off and the ester exchange reaction is carried out. Subsequently, the polymerization reaction was performed at a final temperature of 285 ° C. and a degree of vacuum of 0.1 Torr to obtain a polyester resin having an intrinsic viscosity of 0.54 and a carboxyl group concentration of 13 eq / t. Next, the obtained polyester resin was dried and crystallized at 160 ° C. for 6 hours, followed by solid phase polymerization at 220 ° C. and a vacuum degree of 0.3 Torr for 9 hours. The intrinsic viscosity was 0.90 and the carboxyl group concentration was A polyester resin I having 15 eq / t, a melting point of 255 ° C., and a glass transition temperature (Tg) of 83 ° C. was obtained.

(10) Polyester resin J
100 parts by weight of dimethyl terephthalate, trimethyl trimellitic acid (added so as to have a molar ratio of dimethyl terephthalate / trimethyl trimellitic acid = 99.9 / 0.1), 57.5 parts by weight of ethylene glycol, 0. After melting 06 parts by weight and 0.03 parts by weight of antimony trioxide at 150 ° C. in a nitrogen atmosphere, the temperature is raised to 230 ° C. over 3 hours with stirring, methanol is distilled off, and a transesterification reaction is performed. After the transesterification reaction, 0.015 parts by mass of phosphoric acid (equivalent to 1.4 mol / t) and 0.031 parts by mass of sodium dihydrogen phosphate dihydrate (equivalent to 1.7 mol / t) were added to ethylene glycol 0 Add ethylene glycol solution (pH 5.0) dissolved in 5 parts by mass and transfer to polycondensation reaction kettle. Thereafter, polymerization and solid phase polymerization were carried out in the same manner as for polyester resin I. Polyester resin J having an intrinsic viscosity of 0.90, a carboxyl group concentration of 15 eq / t, a melting point of 255 ° C., and a glass transition temperature (Tg) of 83 ° C. Got.

(11) Polyester resin K
When the polyester resin A is produced, the aggregated silica particles having a median diameter (average particle diameter) of 2.1 μm measured by a laser diffraction / scattering particle size distribution measuring apparatus LA-700 (manufactured by Horiba, Ltd.) after the transesterification reaction. After adding the ethylene glycol slurry, a polycondensation reaction was performed to obtain a particle master having a particle concentration of 2.0% by weight.
[Composition and formulation of water-based coatings]
An aqueous coating material for forming a [C] layer by coating on a uniaxially oriented film after longitudinal stretching was prepared as follows.

(1) Coating agent A
1. Raw material <1> As an aqueous dispersion / acid component of polyester resin,
Terephthalic acid: 25 mol%
Isophthalic acid: 24 mol%
Sebacic acid: 1 mol%
・ As glycol component,
Ethylene glycol: 27 mol%
Neopentyl glycol: 22 mol%
1,4-butanediol: 1 mol%
A water dispersion of a polyester resin, which is a water-dispersible resin comprising: Here, the solid content concentration (polyester resin concentration) of the aqueous dispersion is 25% by weight, and the remaining 75% by weight is water. The polyester resin has an acid value of 41 KOHmg / g, a glass transition temperature (Tg) of 20 ° C., and a refractive index of 1.52.
In addition, said "mol%" means the mol 100 fraction when the acid component and glycol component of the polyester resin which comprise an easily bonding layer are made into 100 mol% in total.

<2> As an aqueous dispersion of melamine compound / melamine compound,
An aqueous dispersion of an N-methylolated melamine compound (Nicalac MW-12LF (manufactured by Sanwa Chemical Co., Ltd.)), which is a water dispersible resin, was used. The solid content concentration (melamine compound concentration) of the aqueous dispersion is 70% by weight, and the remaining 30% by weight is water.

2. Preparation method of coating liquid It prepared with the following method using the aqueous dispersion of said polyester resin, the aqueous dispersion of a melamine compound, and pure water.

  <1> It mixed so that 5 weight part of melamine compounds (solid content) might be added with respect to 95 weight part of polyester resins (solid content). That is, 380 parts by weight of an aqueous dispersion of polyester resin (of which solid content: 95 parts by weight, water: 285 parts) and 7.14 parts by weight of an aqueous dispersion of melamine compound (of which solid content: 5 parts by weight, water: 2. 14 parts by weight) was blended to obtain a stock solution.

  <2> Pure water was blended so that the solid content of the stock solution (the total solid content of the polyester resin and the melamine compound) was 1.5% by weight.

(2) Coating liquid B
1. Raw material <1> As an aqueous dispersion / acid component of polyester resin,
Terephthalic acid: 28 mol%
Isophthalic acid: 9 mol%
Trimellitic acid: 10 mol%
Sebacic acid: 3 mol%
・ As glycol component,
Ethylene glycol: 15 mol%
Neopentyl glycol: 18 mol%
1,4-butanediol: 17 mol%
A water dispersion of a polyester resin, which is a water-dispersible resin comprising: Here, the solid content concentration (polyester resin concentration) of the aqueous dispersion is 25% by weight, and the remaining 75% by weight is water. The polyester resin has an acid value of 41 KOH mg / g, a glass transition temperature (Tg) of 20 ° C., and a refractive index of 1.58.

<2> As an aqueous dispersion of melamine compound / melamine compound,
An aqueous dispersion of an N-methylolated melamine compound (Nicalac MW-12LF (manufactured by Sanwa Chemical Co., Ltd.)), which is a water dispersible resin, was used. The solid content concentration (melamine compound concentration) of the aqueous dispersion is 70% by weight, and the remaining 30% by weight is water.

<3> Aqueous dispersion of oxazoline compound An aqueous dispersion of an oxazoline-based reactive polymer (Epocross WS-500 (manufactured by Nippon Shokubai Co., Ltd.)) was used as the oxazoline compound as the oxazoline compound. Further, the solid content concentration (oxazoline compound concentration) of the aqueous dispersion is 39% by weight, and the remaining 61% by weight is water.

2. Preparation method of coating liquid The following method was prepared using an aqueous dispersion of the above polyester resin, an aqueous dispersion of a melamine compound, an aqueous dispersion of an oxazoline compound, and pure water.

  <1> To 100 parts by weight of the polyester resin (solid content), 25 parts by weight of the melamine compound (solid content) and 20 parts by weight of the oxazoline compound (solid content) were added. That is, 400 parts by weight of an aqueous dispersion of polyester resin (of which solid content: 100 parts by weight, water: 300 parts) and 35.7 parts by weight of an aqueous dispersion of melamine compound (of which solid content: 25 parts by weight, water: 10. 7 parts by weight) and 66.6 parts by weight of an aqueous dispersion of an oxazoline compound (solid content: 20 parts by weight, 46.6 parts by weight of water) were blended to obtain a stock solution.

<2> Pure water is blended so that the solid content of the stock solution (the solid content of the polyester resin, the solid content of the melamine compound, and the oxazoline compound) is 3.0% by weight. did.
[Formation of [B] layer]
([B1] layer)
A sputter target, which is a mixed sintered material formed of zinc oxide, silicon dioxide, and aluminum oxide, is placed on the sputter electrode 12 using a winding type sputtering apparatus having the structure shown in FIG. Sputtering is performed on the surface of the biaxially oriented polyester film 4 on the sputter electrode 12 side (when the [A] layer is formed, on the [A] layer or when the [A] layer is not formed) [B1] layer was provided on the biaxially oriented polyester film).

The specific operation is as follows. First, in a winding chamber 6 of a winding type sputtering apparatus 5 in which a sputtering target sintered with a composition ratio of zinc oxide / silicon dioxide / aluminum oxide of 77/20/3 is installed on the sputtering electrode 12, The biaxially oriented polyester film 4 is set on the take-out roll 7 so that the surface on which the [B1] layer is provided faces the sputter electrode 12, unwinds, and passes through the guide rolls 8, 9, 10, and the cooling drum 11. Passed through. Argon gas and oxygen gas are introduced at a partial pressure of oxygen of 10% so that the degree of decompression is 2 × 10 ⁻¹ Pa, and an argon / oxygen gas plasma is generated by applying an input power of 4000 W from a DC power source, and sputtering is performed. Thus, a [B1] layer was formed on the surface of the biaxially oriented polyester film 4. The thickness was adjusted by the film transport speed. Then, it wound up on the winding roll 16 through the guide rolls 13, 14, and 15.

([B2] layer)
A sputter target, which is a mixed sintered material formed of zinc oxide, silicon dioxide, and aluminum oxide, is placed on the sputter electrode 12 using a winding type sputtering apparatus having the structure shown in FIG. Sputtering is performed on the surface of the biaxially oriented polyester film 4 on the sputter electrode 12 side (when the [A] layer is formed, on the [A] layer or when the [A] layer is not formed) [B2] layer was provided on the biaxially oriented polyester film).

The specific operation is as follows. First, in the take-up roll 6 of the take-up type sputtering apparatus 5 in which the sputter target 12 having the zinc sulfide / silicon dioxide molar composition ratio sintered at 80/20 is installed on the sputter electrode 12, The biaxially oriented polyester film 4 was set, unwound, and passed through the cooling drum 11 through the guide rolls 8, 9 and 10. Argon gas was introduced so that the degree of decompression was 2 × 10 ⁻¹ Pa, and by applying an input power of 500 W from a high frequency power source, argon gas plasma was generated, and on the surface of the biaxially oriented polyester film 4 by sputtering. A [B2] layer was formed. The thickness was adjusted by the film transport speed. Then, it wound up on the winding roll 16 through the guide rolls 13, 14, and 15.

([B3] layer)
A sputter target, which is a mixed sintered material formed of zinc oxide, silicon dioxide, and aluminum oxide, is placed on the sputter electrode 12 using a winding type sputtering apparatus having the structure shown in FIG. Sputtering is performed on the surface of the biaxially oriented polyester film 4 on the sputter electrode 12 side (when the [A] layer is formed, on the [A] layer or when the [A] layer is not formed) Provided a [B3] layer on the biaxially oriented polyester film).

The specific operation is as follows. First, in the take-up chamber 6 of the take-up type sputtering apparatus 5 in which a sputter target sintered with a sputter electrode 12 having an oxygen atom to oxygen atom ratio (O / Al ratio) of 1.5 is installed. The biaxially oriented polyester film 4 was set on the unwinding roll 7, unwound and passed through the cooling drum 11 through the guide rolls 8, 9 and 10. Argon gas was introduced so that the degree of decompression was 2 × 10 ⁻¹ Pa, and by applying an input power of 500 W from a high frequency power source, argon gas plasma was generated, and on the surface of the biaxially oriented polyester film 4 by sputtering. A [B3] layer was formed. The thickness was adjusted by the film transport speed. Then, it wound up on the winding roll 16 through the guide rolls 13, 14, and 15.
(Comparative Example 1)
After sufficiently drying polyester resin A in a vacuum, it is supplied to an extruder, melted at 285 ° C., filtered through a 3 μm cut filter, extruded into a sheet from a T-shaped base, and a surface temperature of 25 ° C. using an electrostatic application casting method. It was wound around a mirror casting drum and allowed to cool and solidify. This unstretched film was preheated at 85 ° C., then heated to 90 ° C. and stretched 3.4 times in the longitudinal direction to obtain a uniaxially oriented (uniaxially stretched) film. This film was subjected to corona discharge treatment on both sides in air. Subsequently, in order to form [C] layer, the coating agent A which added the easy-lubricant (colloidal silica with a particle size of 150 nm) by the solid content ratio of 2.0 wt% was apply | coated to both said film both surfaces. The coating thickness was set to 150 nm after completion of oriented crystal of the polyester film, that is, after heat treatment.

  Next, the uniaxially stretched film coated with the coating is held by a clip and guided to a preheating zone, dried and preheated at an atmospheric temperature of 120 ° C., and then continuously stretched at a stretching zone of 120 ° C. in the width direction of 3.5. The film was stretched twice, subsequently subjected to a relaxation treatment of 7% for 10 seconds in a heating zone at 230 ° C., and finely stretched again for 0.5% for 10 seconds in a cooling zone at 160 ° C. A biaxially oriented polyester film in which a [C] layer having a thickness of 150 nm was laminated by the above method was obtained.

  The biaxially oriented polyester film had a TD heat shrinkage of 0.3% at 150 ° C. for 30 minutes and a TD heat shrinkage of 0.1% at 190 ° C. for 30 minutes. The laminated polyester film had a thickness of 100 μm.

[A] A coating solution 1 was prepared by diluting 100 parts by weight of urethane acrylate (Forseed 420C manufactured by China Paint Co., Ltd.) with 70 parts by weight of toluene. Next, coating liquid 1 was applied to one side of the biaxially oriented polyester film with a micro gravure coater (gravure wire number 200UR, gravure rotation ratio 100%), dried at 60 ° C. for 1 minute, and then irradiated with ultraviolet rays at 1 J / cm ² . After curing, an [A] layer (denoted as A1) having a thickness of 3 μm was provided.

  A test piece having a length of 100 mm and a width of 100 mm was cut out from the film on which the [A] layer was formed, and the pencil hardness test, surface free energy, and average surface roughness of the [A] layer were evaluated. The results are shown in Table 1.

  Next, a [B1] layer having a thickness of 200 nm was formed on the [A] layer to obtain a gas barrier film. The composition of the [B1] layer was such that the Zn atom concentration was 27.5 atom%, the Si atom concentration was 13.1 atom%, the Al atom concentration was 2.3 atom%, and the O atom concentration was 57.1 atom%.

A test piece having a length of 100 mm and a width of 140 mm was cut out from the obtained gas barrier film, and the water vapor transmission rate was evaluated. The results are shown in Table 1.
(Comparative Example 2)
[A] As a coating liquid for layer formation, instead of urethane acrylate, 100 parts by weight of polyester acrylate (Nippon Kayaku Co., Ltd. FOP-1740) and silicone oil (Toray Dow Corning Co., Ltd. SH190) 0 Add 2 parts by weight, prepare coating liquid 2 diluted with 50 parts by weight of toluene and 50 parts by weight of MEK, and apply coating liquid 2 with a micro gravure coater (gravure wire number 200UR, gravure rotation ratio 100%), After drying at 60 ° C. for 1 minute, a gas barrier film was obtained in the same manner as in Comparative Example 1 except that an ultraviolet ray was irradiated and cured at 1 J / cm ² and a [A] layer (referred to as A2) having a thickness of 5 μm was provided.
(Comparative Example 3)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the [B2] layer was provided to a thickness of 200 nm in place of the [B1] layer.

The composition of the [B2] layer had a zinc sulfide molar fraction of 0.80.
(Comparative Example 4)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that the [B2] layer was provided to a thickness of 200 nm instead of the [B1] layer.

The composition of the [B2] layer had a zinc sulfide molar fraction of 0.80.
(Comparative Example 5)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the [B1] layer was provided to have a thickness of 850 nm.
(Comparative Example 6)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that the [B1] layer was provided to have a thickness of 950 nm.
(Comparative Example 7)
A biaxially oriented polyester film was obtained in the same manner as in Comparative Example 1 except that a uniaxially oriented film was formed after longitudinal stretching, and then one side was subjected to corona treatment and the [C] layer was laminated only on the corona-treated surface. Thereafter, the gas barrier properties were the same as in Comparative Example 1 except that the [B1] layer was formed to a thickness of 100 nm directly on the non-laminated surface of the [C] layer of the biaxially oriented polyester film without forming the [A] layer. A film was obtained.
(Comparative Example 8)
A gas barrier film was obtained in the same manner as in Comparative Example 7 except that the [B2] layer was formed to a thickness of 100 nm.
(Comparative Example 9)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the thickness of the [B1] layer was 1200 nm.
(Comparative Example 10)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the thickness of the [B2] layer was 1200 nm.
(Comparative Example 11)
[A] 10 parts by weight of “Separjon” (registered trademark) VH100 manufactured by Sumitomo Seika Co., Ltd., which is a coating agent in which an EVOH resin is dispersed in water, instead of urethane acrylate, is used as a coating liquid for layer formation. (Solid content concentration: 15% by mass) Weighed out, added 1.9 parts by weight of water and 0.6 parts by weight of isopropanol as a diluent solvent, and stirred for 30 minutes to prepare a coating liquid 3 having a solid content concentration of 12%. . Next, a gas barrier film was obtained in the same manner as in Comparative Example 1 except that coating was performed using a wire bar, drying was performed at a temperature of 120 ° C. for 40 seconds, and an [A] layer having a thickness of 1 μm (referred to as A3) was provided. It was.
(Comparative Example 12)
A gas barrier film was obtained in the same manner as in Comparative Example 11 except that the [B2] layer was provided to a thickness of 200 nm instead of the [B1] layer.
(Comparative Example 13)
[A] A gas barrier film was obtained in the same manner as in Comparative Example 2 except that 0.2 parts by weight of silicone oil (SH190 manufactured by Toray Dow Corning Co., Ltd.) was not added to the coating liquid for layer formation.
(Comparative Example 14)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the [B3] layer was provided to a thickness of 200 nm instead of the [B2] layer.

Regarding the composition of the Al ₂ O ₃ layer, the atomic ratio of oxygen atoms to aluminum atoms (O / Al ratio) was 1.65.
(Example 1-1)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.
(Example 1-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.
(Example 1-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that 96 parts by weight of polyester resin A and 4 parts by weight of polyester resin B were mixed and used.
(Example 1-4)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.
(Example 1-5)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that 92 parts by weight of polyester resin A and 8 parts by weight of polyester resin B were mixed and used.
(Example 1-6)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.
(Example 1-7)
A gas barrier film was obtained in the same manner as in Comparative Example 5 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.
(Example 1-8)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that 94 parts by weight of polyester resin A and 6 parts by weight of polyester resin B were mixed and used.

In Examples 1-1 to 1-8 and Comparative Examples 1 to 14, the water vapor permeability of the gas barrier film and the transmittance of the biaxially oriented polyester film before laminating the [A] layer and the [B] layer at a wavelength of 380 nm Evaluated. The results are shown in Table 1.
(Example 2-1)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the polyester resin C was used.
(Example 2-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that the polyester resin C was used.
(Example 2-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the polyester resin C was used.
(Example 2-4)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that the polyester resin C was used.
(Example 2-5)
A gas barrier film was obtained in the same manner as in Comparative Example 5 except that the polyester resin C was used.
(Example 2-6)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that the polyester resin C was used.

Examples 2-1 to 2-6 and Comparative Examples 1 to 14 evaluated the water vapor transmission rate of the gas barrier film and the oligomer precipitation amount of the biaxially oriented polyester film before the [A] layer and [B] layer were laminated. . The results are shown in Table 2.
(Example 3-1)
An unstretched film was obtained in the same manner as in Comparative Example 1. Next, an infrared heater having a wavelength of 1.1 μm between a pair of rolls made of a metal roll of φ250 mm provided with a nip roll coated with silicone rubber of φ250 mm (rubber hardness 60 degrees) as shown in FIGS. 3 and 4 (600V, 24kW / m) and a condensing heater (“Near-Infrared Line Heater: HYL-1000” manufactured by Hibeck Co., Ltd.) equipped with an infrared reflector, the center position in the longitudinal direction of the film on the upper and lower sides of the film The lengths a and b in the longitudinal direction on the film surface by the infrared focused light are both 30 mm and 30 mm, and the distances A and B between the condensing heater housing and the film surface are 20 mm. A roll stretching apparatus adjusted as described above was used. After the film is preheated at a roll temperature of 70 ° C. in a roll group consisting of 10 φ250 mm metal rolls at a conveyance speed of 10 m / min before stretching, the upper and lower condenser heaters of the film according to the present invention A gas barrier film was obtained in the same manner as in Comparative Example 1 except that a uniaxially oriented film was obtained by longitudinally stretching 3.0 times in the longitudinal direction while applying a total power of 20 kW (upper side 13 kW, lower side 7 kW).
(Example 3-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1.
(Example 3-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1.
(Example 3-4)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1, except that the preheating was set at 78 ° C.
(Example 3-5)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1.
(Example 3-6)
A gas barrier film was obtained in the same manner as in Comparative Example 5 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1.
(Example 3-7)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that a uniaxially oriented film was obtained in the same manner as in Example 3-1.

Examples 3-1 to 3-7 and Comparative Examples 1 to 14 evaluated the water vapor permeability of the gas barrier film and the number of scratches on the biaxially oriented polyester film before the [A] layer and [B] layer were laminated. The results are shown in Table 3.
(Example 4-1)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 70 nm.
(Example 4-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 70 nm.
(Example 4-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was set to 70 nm.
(Example 4-4)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 150 nm.
(Example 4-5)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 70 nm.
(Example 4-6)
A gas barrier film was obtained in the same manner as in Comparative Example 5 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 70 nm.
(Example 4-7)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that the coating agent B was used for forming the [C] layer and the thickness of the [C] layer was 70 nm.

Examples 4-1 to 4-7 and Comparative Examples 1 to 14 evaluated the water vapor permeability of the gas barrier film, the waviness amplitude and interference fringes of the [A] layer-laminated biaxially oriented polyester film before the [B] layer was laminated. . The results are shown in Table 4.
(Example 5-1)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.
(Example 5-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.
(Example 5-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.
(Example 5-4)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.
(Example 5-5)
A gas barrier film was obtained in the same manner as in Comparative Example 5, except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.
(Example 5-6)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that 65 parts by weight of polyester resin A, 10 parts by weight of polyester resin D, and 25 parts by weight of polyester resin E were mixed and used.

Examples 5-1 to 5-6 and Comparative Examples 1 to 14 are the pre-molding / post-molding water vapor transmission rate, the degree of plane orientation of the biaxially oriented polyester film before laminating the [A] layer and the [B] layer, 190 The elongation at break at 0 ° C. was evaluated. The results are shown in Table 5.
(Example 6-1)
A gas barrier film was obtained in the same manner as in Comparative Example 1 except that the polyester resin G was used.
(Example 6-2)
A gas barrier film was obtained in the same manner as in Comparative Example 2 except that the polyester resin G was used.
(Example 6-3)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the polyester resin G was used.
(Example 6-4)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the polyester resin F was used.
(Example 6-5)
A gas barrier film was obtained in the same manner as in Comparative Example 3 except that the polyester resin H was used.
(Example 6-6)
A gas barrier film was obtained in the same manner as in Comparative Example 4 except that the polyester resin G was used.
(Example 6-7)
A gas barrier film was obtained in the same manner as in Comparative Example 5 except that the polyester resin G was used.
(Example 6-8)
A gas barrier film was obtained in the same manner as in Comparative Example 6 except that the polyester resin G was used.

Examples 6-1 to 6-8 and Comparative Examples 1 to 14 evaluate the water vapor permeability of the gas barrier film and the elongation retention of the biaxially oriented polyester film before the [A] layer and [B] layer are laminated. did. The results are shown in Table 6.
(Example 7-1)
After sufficiently drying polyester resin I in a vacuum, it is supplied to an extruder, melted at 285 ° C., filtered through a 3 μm cut filter, extruded into a sheet from a T-shaped base, and a surface temperature of 25 ° C. using an electrostatic application casting method. It was wound around a mirror casting drum and allowed to cool and solidify. This unstretched film was preheated at 80 ° C., then heated to 85 ° C. and stretched 3.8 times in the longitudinal direction to obtain a uniaxially oriented (uniaxially stretched) film. This film was subjected to corona discharge treatment on both sides in air. Next, a coating agent A to which a lubricant (colloidal silica having a particle size of 150 nm) was added at a solid content ratio of 2.0 wt% was applied to both sides of the above film for forming the [C] layer. The coating thickness was set to 150 nm after completion of oriented crystal of the polyester film, that is, after heat treatment.

Next, the uniaxially stretched film coated with the coating is held by a clip and guided to a preheating zone, dried and preheated at an atmospheric temperature of 120 ° C., and then continuously stretched in the width direction by 4.5 at a stretching zone of 120 ° C. The film was stretched twice, subsequently subjected to a relaxation treatment of 7% for 20 seconds in a heating zone at 170 ° C., and subjected to 0.5% fine stretching again for 10 seconds in a cooling zone at 160 ° C. A biaxially oriented polyester film in which a [C] layer having a thickness of 150 nm was laminated by the above method was obtained. Subsequently, the film unwound from the film roll was heated at 160 ° C., and an oven having an inlet and an outlet was used. The film was wound at the outlet of the oven so that the tension applied to the film was 50 N / m. And 5% for TD and 8% for TD. Subsequently, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 1 to obtain a gas barrier film.
(Example 7-2)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 2 to obtain a gas barrier film.
(Example 7-3)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 3 to obtain a gas barrier film.
(Example 7-4)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1 except that the polyester resin J was used. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 3 to obtain a gas barrier film.
(Example 7-5)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1 except that the heating zone after stretching in the transverse direction was set to 210 ° C. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 3 to obtain a gas barrier film.
(Example 7-6)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 4 to obtain a gas barrier film.
(Example 7-7)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 5 to obtain a gas barrier film.
(Example 7-8)
A film roll heat-treated in an oven was obtained in the same manner as in Example 7-1. Next, the [A] layer and the [B] layer were laminated in the same manner as in Comparative Example 6 to obtain a gas barrier film.

  Examples 7-1 to 7-8 and Comparative Examples 1 to 14 are the water vapor permeability of the gas barrier film, the linear expansion coefficient and the elongation of the biaxially oriented polyester film before the [A] layer and [B] layer are laminated. Retention was evaluated. The results are shown in Table 7.

  Since the gas barrier film of the present invention is excellent in gas barrier properties against oxygen gas, water vapor and the like, it can be usefully used, for example, as a packaging material for foods, pharmaceuticals, etc., and as an electronic device member for thin televisions, solar cells, etc. The application is not limited to these.

1: Biaxially oriented polyester film 2: [A] layer 3: [B] layer 4: Biaxially oriented polyester film 5: Winding type sputtering device 6: Winding chamber 7: Winding rolls 8, 9, 10: Winding Delivery side guide roll 11: Cooling drum 12: Sputtering electrodes 13, 14, 15: Winding side guide roll 16: Winding roll 17: Roll stretching device 18: Film 19: Low speed roll 19 ': High speed roll 20: Nip roll 20' : Nip roll 21: Condensing heater on the upper side of the film and its housing 21 ′: Condensing heater on the lower side of the film and its housing 22: A portion 22 ′ of the irradiation length a on the film surface by the upper condensing heater : The portion 23 of the irradiation length b on the film surface by the lower light collecting heater 23: The focal point 23 'of the upper light collecting heater 23: The focus 24 of the lower light collecting heater 24: Distance A from the housing bottom side and condensing heater to the film plane
24 ': Distance B from the upper end of the casing of the lower condenser heater to the film surface
25: Irradiation width at the lower end of the casing of the upper condensing heater 25 ': Irradiation width of the upper end of the casing of the lower condensing heater

Claims (11)

A gas barrier film in which the following [A] layer and [B] layer are laminated in this order on at least one surface of a biaxially oriented polyester film satisfying any of the following [1] to [7].
[A] layer: a crosslinked resin layer having a pencil hardness of H or more and a surface free energy of 45 mN / m or less [B] layer: a silicon-containing inorganic layer having a thickness of 10 to 1000 nm [1] containing an ultraviolet absorber and having a wavelength The transmittance at 380 nm is 5% or less. [2] The amount of oligomer precipitation on the [A] layer lamination surface after heat treatment at 180 ° C. for 30 minutes is 3.0 mg / m ² or less. [3] The length is 5 mm or more and the maximum depth. a polyester film having an easy adhesion layer ([C] layer) on at least one surface is 0.5μm or more flaws 70 / ^{m 2} or less [4], met 50~150nm a layer thickness of [C] layer In the state where the [C] layer and the [A] layer are laminated in this order, the undulation amplitude of the spectral reflectance at the measurement wavelength of 400 to 600 nm on the [A] layer side is 2.0% or less [5] at 190 ° C. Film length direction and width direction The direction elongation coefficient (fn) on both surfaces of the polyester film is 0.14 or less. [6] Aging treatment is performed for 36 hours in an environment of a temperature of 120 ° C. and a humidity of 100%. 40-100% elongation retention after performing
[7] The linear expansion coefficient α which is the average of the linear expansion coefficient (α-MD) of MD from 50 ° C. to 150 ° C. and the linear expansion coefficient (α-TD) of TD is 22 ppm / ° C. or less. The gas barrier film according to claim 1, wherein the [B] layer is composed of a composition containing a zinc compound and a silicon oxide. The gas barrier film according to claim 2, wherein the [B] layer is any of the following [B1] layer or [B2] layer.
[B1] layer: a layer composed of a coexisting phase of zinc oxide, silicon dioxide and aluminum oxide [B2] layer: a layer composed of a coexisting phase of zinc sulfide and silicon dioxide The [B] layer is a [B1] layer, and the [B1] layer has a zinc (Zn) atom concentration of 20 to 40 atom% and a silicon (Si) atom concentration of 5 to 5 as measured by ICP emission spectroscopy. 4. The gas barrier film according to claim 3, wherein the gas barrier film has a composition of 20 atom%, aluminum (Al) atom concentration of 0.5 to 5 atom%, and oxygen (O) atom concentration of 35 to 70 atom%. The [B] layer is a [B2] layer, and the [B2] layer has a composition in which the molar fraction of zinc sulfide with respect to the total of zinc sulfide and silicon dioxide is 0.7 to 0.9. The gas barrier film according to claim 3. 6. The gas barrier film according to claim 1, wherein the [A] layer has an average surface roughness Ra of 1 nm or less. The gas barrier film according to claim 1, wherein the [B] layer has an average surface roughness Ra of 1.5 nm or less. The gas barrier film according to any one of claims 1 to 7, further comprising a transparent conductive layer between the surface of the [B] layer or the biaxially oriented polyester film and the [A] layer. The transparent conductive layer includes any of indium tin oxide (ITO), zinc oxide (ZnO), aluminum-containing zinc oxide (Al / ZnO), gallium-containing zinc oxide (Ga / ZnO), metal nanowires, and carbon nanotubes. The gas-barrier film in any one of Claims 1-8. The solar cell which has a gas-barrier film in any one of Claims 1-9. A display element having the gas barrier film according to claim 1.

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