JP2012254585A - Laminate and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate that does not leach a foreign substance or residual solvent, and has superior gas barrier properties, light blocking effect, and strength.SOLUTION: In the laminate, a thermoplastic resin film, a thin film layer including oxidized aluminum or oxidized silicon provided on at least one side surface of the thermoplastic resin film, a barrier film including the gas barrier protective layer provided on the thin film layer, and a polyester resin film area laminated so that the gas barrier protective layer of the barrier film and the polyester resin film face to, each other. The laminate is bonded by forming a bond between an atom in the gas barrier protective layer and an atom in the polyester resin film the gas barrier protective layer on at least part of an interfacial surface of the gas barrier protective layer obtained by coating solution including water-soluble polymer having hydroxyl and alkoxysilane and the polyester resin film.

Description

  The present invention relates to a laminate, and more specifically, a barrier film in which a thin film layer and a gas barrier protective layer are provided on a thermoplastic resin film, and a polyester resin film. The present invention relates to a laminated body bonded without using an adhesive so as to face a polyester resin film and a method for producing the same.

  A package in which a film or the like is processed into a bag shape is used. In such a package, a multifunctional film in which various materials are laminated is used as a film to be used in order to develop a desired function depending on the contents to be filled. As such a multifunctional film, a polyester resin that has high strength and excellent gas barrier properties as a gas barrier film as a packaging material for foods and drinks, pharmaceuticals, electronic members, etc. A laminated film in which films are laminated is known.

  The package is generally performed by processing a long film, but in order to process it into a bag shape, the end portions of the films are overlapped and bonded. As a method of bonding films, a laminate resin (adhesive) is applied to the ends of the films to be bonded, and the films are pressed and sealed, or the two films are overlapped and heated at the ends. In general, a so-called heat sealing process is performed to add and fuse. Moreover, as for the laminated film used as the material of the package, two or more kinds of films are laminated by melt extrusion, or two or more kinds of films are laminated via a laminate resin.

  In the case of a package made by bonding films made of different materials through a laminate resin, the laminate resin component may gradually elute or volatilize in the package, which may alter the contents. In the medical field where importance is placed on the property, contamination of the contents by the laminate resin sometimes becomes a problem. In addition, the laminate resin itself may deteriorate due to long-term use of the package, and particularly in exterior applications that are used outdoors, the weather resistance of the laminated package may become a problem. In addition, in the laminating technique using an adhesive, since a resin component diluted in a solvent is generally applied, the solvent remains after laminating to form a final product such as a package. There was a case.

  By the way, surface modification of a material using radiation or an electron beam has been conventionally performed. For example, Japanese Patent Application Laid-Open No. 2003-119293 (Patent Document 1) proposes that a crosslinked composite fluororesin can be obtained by irradiating the fluororesin with radiation. In Journal of Photopolymer Science and Technology Vol.19, No. 1 (2006), pp123-127 (Non-patent Document 1), a polytetrafluoroethylene film and a polyimide film are laminated and an electron beam ( In the following, it has been proposed to bond each other by irradiating EB. In Material Transactions Vol.50, No.7 (2009), pp1859-1863 (Non-patent Document 2), the surface of the polycarbonate resin is covered with a nylon film, and an electron beam (hereinafter abbreviated as EB) may be applied from above. A technique for adhering a nylon film to a polycarbonate resin surface has been proposed. Furthermore, the Journal of the Japan Institute of Metals, Vol. 72, No. 7 (2008), pp 526-531 (Non-patent Document 3) can be bonded to each other by irradiating EB from a nylon film placed on silicone rubber. Is described.

JP 2003-119293 A

Journal of Photopolymer Science and Technology Vol.19, No. 1 (2006), pp123-127 Material Transactions Vol.50, No. 7 (2009), pp1859-1863 Journal of the Japan Institute of Metals, Vol. 72, No. 7 (2008), pp 526-531

  In the production of a laminate in which a barrier film having a thin film layer and a gas barrier protective layer and a polyester resin film are laminated on a thermoplastic resin film known as a gas barrier film, the present inventors have It has been found that by irradiating an electron beam to a conductive film and / or a polyester resin film, both films can be firmly bonded without using a laminate resin or the like. And even if it is a laminate that has been conventionally bonded to each other with an adhesive, such as a laminate in which a barrier film including a gas barrier protective layer and a polyester resin film are stacked, according to electron beam irradiation, Even without using an adhesive, it was found that a bond was formed between the atoms on the barrier film side and the atoms on the polyester resin film side so that they could be firmly bonded to each other. The present invention is based on this finding.

  Accordingly, an object of the present invention is a laminate in which a gas barrier film and a polyester resin film are bonded without using an adhesive, and foreign matter and residual solvent do not ooze out. It is providing the laminated body which is excellent in property and intensity | strength.

The laminate according to the present invention includes a thermoplastic resin film, a thin film layer made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film, and a gas barrier protective layer provided on the thin film layer. A laminated body in which the barrier film and the polyester resin film are laminated so that the gas barrier protective layer of the barrier film and the polyester resin film face each other,
The gas barrier protective layer comprises a film obtained by applying a solution containing at least a water-soluble polymer having a hydroxyl group and alkoxysilane,
In at least a part of the interface between the gas barrier protective layer and the polyester resin film, a bond is formed between an atom in the gas barrier protective layer and an atom in the polyester resin film, and the gas barrier property The protective layer and the polyester resin film are bonded without using an adhesive.

  Further, as an aspect of the present invention, at least part of the interface between the gas barrier protective layer and the polyester resin film, oxygen between the atoms in the gas barrier protective layer and the atoms in the polyester resin film, A bond is preferably formed through an atom, nitrogen atom or hydroxyl group.

Further, as an aspect of the present invention, the alkoxysilane is represented by the following general formula:
R _1n Si (OR ₂ ) _m
(In the formula, R ₁ and R ₂ each independently represent an organic group having 1 to 8 carbon atoms, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents an Si atom. Represents the value.)
It is preferable that it is represented by these.

  In one embodiment of the present invention, the water-soluble polymer having a hydroxyl group is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, and an ethylene-vinyl alcohol copolymer. It is preferably a seed or a mixture of two or more.

  Moreover, as an aspect of the present invention, the polyester resin film is preferably a polyethylene terephthalate film.

Moreover, the production method as another aspect of the present invention is a method for producing a laminate in which a barrier film and a polyester resin film are laminated,
Gas barrier property of a barrier film comprising a thermoplastic resin film, a thin film layer made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film, and a gas barrier protective layer provided on the thin film layer Irradiating the protective layer surface and / or at least one surface of the polyester resin film with an electron beam,
The gas barrier protective layer surface and / or the polyester resin film surface irradiated with the electron beam are superposed and bonded to each other.

  Moreover, as an aspect of the present invention, it is preferable to perform electron beam irradiation before and / or after the barrier film and the polyester resin film are overlapped.

  Moreover, as another aspect of the present invention, the bonding is preferably performed by applying pressure, and the bonding is preferably performed by heating.

  According to the present invention, it comprises a thermoplastic resin film, a thin film layer made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film, and a gas barrier protective layer provided on the thin film layer. In the laminated body in which the barrier film and the polyester resin film are laminated so that the gas barrier protective layer of the barrier film and the polyester resin film face each other, the gas barrier protective layer and the polyester resin film Since at least a part of the interface has a bond formed between the atom in the gas barrier protective layer and the atom in the polyester resin film, the barrier property can be obtained even if it is not bonded via an adhesive. A laminate in which the film and the polyester resin film are firmly bonded is obtained. As a result, it is possible to realize a laminate that does not exude foreign matter, residual solvent, and the like and is excellent in gas barrier properties, light shielding properties, and strength.

It is the schematic sectional drawing which showed one Embodiment of the laminated body of this invention. It is the schematic cross section which expanded the interface (adhesion surface) of the laminated body. It is the schematic diagram which showed one Embodiment of the manufacturing method of the laminated body by this invention. It is the schematic schematic diagram which expanded a part of manufacturing process. It is the schematic diagram which showed another embodiment of the manufacturing method of the laminated body by this invention. It is the schematic diagram which showed another embodiment of the manufacturing method of the laminated body by this invention. It is the schematic diagram which showed another embodiment of the manufacturing method of the laminated body by this invention.

  Hereinafter, the laminated body by this invention is demonstrated, referring drawings. As shown in FIG. 1, the laminate according to the present invention has a structure in which a barrier film 1 and a polyester resin film 2 are laminated without using an adhesive. The barrier film 1 includes a thermoplastic resin film 11, a thin film layer 12 made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film 11, and a gas barrier protective layer 13 provided on the thin film layer 12. Thus, the laminate of the present invention is a laminate in which the gas barrier protective layer 13 of the barrier film 1 and the polyester resin film 2 are stacked so as to face each other.

  In the barrier film 1 constituting the laminate according to the present invention, the gas barrier protective layer 13 comprises a film obtained by applying a solution containing at least a water-soluble polymer having a hydroxyl group and alkoxysilane. In the present invention, a bond is formed between an atom in the gas barrier protective layer 13 and an atom in the polyester resin film 2 on at least a part of the adhesive surface between the gas barrier protective layer 13 and the polyester resin film 2. Thus, the barrier film 1 and the polyester resin film 2 are firmly bonded. A gas barrier protective layer obtained by applying a solution containing a water-soluble polymer having a hydroxyl group such as polyvinyl alcohol and an alkoxysilane does not have self-adhesiveness or heat-sealability, and therefore usually has barrier properties. Even if the polyester resin film 2 is laminated on the surface of the gas barrier protective layer 13 of the film 1, hydrogen bonds and covalent bonds are not formed between them, and therefore the two cannot be bonded without using an adhesive. In the present invention, as will be described later, the surface of the gas barrier protective layer 13 of the barrier film 1 and / or the surface of the polyester resin film 2 is irradiated with an electron beam to generate radicals. As shown in FIG. A bond is formed between an atom in the protective protective layer 13 and an atom on the surface of the polyester resin film 2, or an oxygen atom between an atom in the gas barrier protective layer 13 and an atom on the surface of the polyester resin film 2 By forming a bond via a nitrogen atom or a hydroxyl group, the barrier film 1 and the polyester resin film 2 are firmly bonded without using an adhesive. Further, radicals generated by electron beam irradiation and oxygen in the air are combined, and there may be OH groups on the surface of the gas barrier protective layer 13 and / or the polyester resin film 2 of the barrier film 1, In that case, a hydrogen bond may be formed between the gas barrier protective layer 13 and the polyester resin film 2. The generation of radicals by electron beam irradiation is confirmed by identifying the free radical species existing in the film after electron beam irradiation using an electron spin resonance apparatus (hereinafter also referred to as ESR). be able to.

  Moreover, the laminated body which bonded and bonded the barrier film 1 and the polyester resin film 2 by electron beam irradiation, as shown in FIG. 2, the atoms of the gas barrier protective layer of the barrier film and the surface of the polyester resin film 2 Since a bond is formed between the atoms, a laminate that does not peel can be obtained without using any adhesive. The presence of hydrogen bonds can be confirmed by immersing the laminate in water or an alcohol solution and confirming the presence or absence of peeling. When both films are bonded to each other only by hydrogen bonds, when the laminate is immersed in water or an alcohol solution, the hydrogen bonds formed between the two films are broken and water or alcohol hydrogen atoms or oxygen atoms are destroyed. And the hydrogen bond is re-formed, the adhesive force disappears and the two peel off. Therefore, it can be confirmed whether the adhesion is due to bonding as shown in FIG. 2 or only due to hydrogen bonding.

  Hereinafter, the barrier film and the polyester resin film constituting the laminate according to the present invention will be described.

<Barrier film>
As shown in FIG. 1, the barrier film 1 is provided on a thermoplastic resin film 11, a thin film layer 12 made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film 11, and a thin film layer 12. A gas barrier protective layer 13. Although the barrier film 1 is not shown, the thin film layer 12 and the gas barrier protective layer 13 may be provided not only on one surface of the thermoplastic resin film 11 but also on both surfaces thereof.

  In the barrier film 1 used in the laminate according to the present invention, the thin film layer 12 and the gas barrier protective film 13 form, for example, a chemical bond, a hydrogen bond, or a coordinate bond by a hydrolysis / co-condensation reaction. The adhesion between the thin film layer 12 and the gas barrier protective layer 13 is improved, and a better gas barrier effect can be exhibited by the synergistic effect of the two layers.

  As the thermoplastic resin film, any plastic film that can support a thin film layer made of aluminum oxide or silicon oxide can be used. For example, polyolefin resin such as polyethylene, polypropylene, polybutene, ( (Meth) acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinylidene chloride resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, polycarbonate resin, fluorine resin, polyvinyl acetate resin, acetal Polyester resin such as polyethylene resin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyamide resin such as nylon 6 and nylon 66, etc. You It is possible. Among these, polyethylene terephthalate (PET) is preferable, and transparent one is more preferable.

  The thermoplastic resin film may be uniaxially or biaxially stretched, and the thickness is preferably about 10 to 200 μm, particularly about 10 to 100 μm. If necessary, the surface may be coated with an anchor coating agent or the like to be subjected to a surface smoothing treatment or the like.

The thin film layer is a thin film of aluminum oxide represented by a general formula: AlO _x (wherein x represents a number of 0.5 to 1.5), or a general formula: SiO _x (where, x Represents a number of 0 to 2), and is formed on the surface of a thermoplastic resin film. As the aluminum oxide thin film represented by the above general formula, an aluminum oxide thin film in which the value of x increases in the depth direction from the film surface toward the inner surface can also be used. In the above, as the value of x, basically, x = 0.5 or more can be used. However, when x = less than 1.0, it is easy to be colored, and transparency, microwave oven Since it is inferior in suitability, it is preferable to use x = 1.0 or more. As the upper limit, those up to x = 1.5 in which aluminum and oxygen are completely oxidized can be used.

Moreover, as a thin film of silicon oxide represented by the above general formula, the value of x is preferably 1.3 to 1.9. The silicon oxide thin film may be mainly composed of silicon oxide, and may further contain at least one kind of compound composed of one kind of carbon, hydrogen, silicon, or oxygen, or two or more kinds of elements by a chemical bond or the like. For example, when a compound having a C—H bond, a compound having a Si—H bond, or a carbon unit is in the form of graphite, diamond, fullerene, or the like, the raw material organosilicon compound or a derivative thereof is further added. It may be contained by a chemical bond or the like. For example, hydrocarbons having a CH 3 site, hydrosilica such as SiH ₃ silyl, SiH ₂ silylene, and hydroxyl derivatives such as SiH ₂ OH silanol can be used. As content which said compound contains in the vapor deposition film | membrane of a silicon oxide, it is 0.1-50 mass%, Preferably it is 5-20 mass%. Moreover, when a silicon oxide thin film contains the said compound, it is preferable that content of a compound is reducing toward the depth direction from the surface of the vapor deposition film | membrane of a silicon oxide. As a result, the impact resistance and the like are enhanced by the above compound on the surface of the silicon oxide vapor deposition film, and on the other hand, since the content of the above compound is small at the interface with the base film, the vapor deposition of the base film and the silicon oxide The tight adhesion with the film becomes strong.

  The film thickness of the thin film layer is preferably selected and formed arbitrarily within a range of, for example, about 10 to 3000 mm, particularly about 60 to 1000 mm. The thin film layer may be crystalline or non-crystalline.

  In the present invention, when the total light transmittance of the thermoplastic resin film constituting the barrier film is 100%, aluminum oxide or silicon oxide is deposited so that the total light transmittance after deposition is less than 90%. It is particularly preferable to deposit aluminum oxide or silicon oxide so that the total light transmittance after deposition is 85% or more and less than 90% when the total light transmittance of the base film is 100%. . When the total light transmittance after vapor deposition is 90% or more after vapor deposition, although the transparency is sufficient, the gas barrier property, particularly the gas barrier property against water vapor, may not be sufficiently high. Moreover, when the total light transmittance after vapor deposition is less than 85%, although the gas barrier property is excellent, the final transparency may not reach the total light transmittance of the thermoplastic resin film.

  Next, a method for forming a thin film layer on a thermoplastic resin film will be described. As a method for forming the thin film layer, for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum deposition method, a sputtering method, or an ion plating method, a plasma chemical vapor deposition method, a thermochemistry, or the like. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a vapor deposition method or a photochemical vapor deposition method can be given. In addition, when manufacturing the film which consists of a transparent laminated body used for the packaging material, a vacuum vapor deposition method is mainly used and a plasma chemical vapor deposition method is also used partially.

In addition, for example, a composite film composed of two or more vapor-deposited films of different kinds of inorganic oxides can be formed by using both physical vapor deposition and chemical vapor deposition. In the case of forming an aluminum oxide thin film in which the value of x increases in the depth direction from the film surface to the inner surface, the aluminum oxide thin film is disclosed in Japanese Patent Application Laid-Open No. 10-226011 by the present applicant. It can be manufactured by the method. The degree of vacuum deposition chamber, before ^introduction of oxygen 10 ^-2 to 10 -8 mbar approximately, in ^particular, is preferably about 10 ^-3 to 10 -7 mbar, in the post-oxygen ^{introduction,} 10 -1 to 10 ^{- About 6} mbar, especially about 10 ⁻² to 10 ⁻⁵ mbar is preferable. The amount of oxygen introduced varies depending on the size of the vapor deposition machine. For the oxygen to be introduced, an inert gas such as argon gas, helium gas, nitrogen gas or the like may be used as a carrier gas within a range where there is no problem. As a conveyance speed of the thermoplastic resin film used as a base material, about 10-800 m / min, especially about 50-600 m / min are preferable. Moreover, the silicon oxide thin film layer in which the content of the compound as described above decreases from the surface of the deposited silicon oxide film in the depth direction is described in Japanese Patent Application Laid-Open No. 2008-143097 by the applicant. It can be formed by such a method.

  In the present invention, the surface of the thin film layer formed as described above may be subjected to oxygen plasma treatment. The amount of oxygen introduced for the oxygen plasma treatment varies depending on the size of the vapor deposition apparatus and the like, but is usually about 50 sccm to 2000 sccm, and particularly preferably about 300 sccm to 800 sccm. Here, sccm means the average amount of oxygen introduced (cc) per minute in the standard state (STP: 0 ° C., 1 atm). For the oxygen to be introduced, an inert gas such as argon gas, helium gas, nitrogen gas or the like may be used as a carrier gas within a range where there is no problem. As described above, the method for forming a thin film made of aluminum oxide or silicon oxide on the thermoplastic resin film and the method for subjecting the surface of the thin film made of aluminum oxide or silicon oxide to oxygen plasma treatment as required have been described. Thus, the present invention is not limited to those obtained by these methods.

  Next, the gas barrier protective layer provided on the thin film layer formed as described above will be described. The gas barrier protective layer can be formed by coating with a solution containing at least a water-soluble polymer having a hydroxyl group and alkoxysilane. Examples of the water-soluble polymer having at least a hydroxyl group include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, an ethylene-vinyl alcohol copolymer, and the like. Polyvinyl alcohol is preferred. These resins may be commercially available. For example, as an ethylene / vinyl alcohol copolymer, Kuraray Co., Ltd., Eval EP-F101 (ethylene content: 32 mol%), Nippon Synthetic Chemical Industry Co., Ltd., Soarnol D2908 (ethylene content; 29 mol%) and the like can be used. Also, as polyvinyl alcohol, RS-110 (degree of saponification = 99%, degree of polymerization = 1,000) manufactured by Kuraray Co., Ltd., Kuraray Poval LM-20SO (degree of saponification = 40%) manufactured by the same company. Degree of polymerization = 2,000), Gohsenol NM-14 (degree of saponification = 99%, degree of polymerization = 1,400) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. can be used.

As alkoxysilane, the general formula:
R _1n Si (OR ₂ ) _m
(In the formula, R ₁ and R ₂ each independently represent an organic group having 1 to 8 carbon atoms, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents an Si atom. Can be suitably used. In the above formula, specific examples of the organic group represented by R ₁ include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group. , T-butyl group, n-hexyl group, n-octyl group, and other alkyl groups. Specific examples of the alkoxysilane include, for example, tetramethoxysilane: Si (OCH ₃ ) ₄ , tetraethoxysilane: Si (OC ₂ H ₅ ) ₄ , tetrapropoxysilane: Si (OC ₃ H ₇ ) ₄ , tetrabutoxysilane. : Si (OC ₄ H ₉ ) ₄ or the like can be used.

  The above-mentioned water-soluble polymer and alkoxysilane are mixed, and if desired, a solution to which a sol-gel method catalyst, water, and an organic solvent are added is applied to the surface of a thin film made of aluminum oxide or silicon oxide. A gas barrier protective layer can be formed by condensation. In the present invention, a composite polymer layer in which two or more of the above-mentioned coating films are stacked can be formed on a thin film made of aluminum oxide or silicon oxide.

  Moreover, in this invention, a silane coupling agent can be added to said coating liquid for gas barrier property protective layer formation, and the gas barrier property protective layer obtained by this is especially preferable. As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used. In particular, an organoalkoxysilane having an epoxy group is suitable, for example, γ-glycidoxypropyltrimethoxy. Silane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, or the like can be used. The above silane coupling agents may be used alone or in combination of two or more. In this invention, the usage-amount of the above silane coupling agents can be used within the range of about 1-20 mass parts with respect to 100 mass parts of said alkoxysilane.

  As a coating method of the coating solution for forming the gas barrier protective layer, conventionally known means such as roll coating such as gravure roll coater, spray coating, spin coating, dipping, brush, bar code, applicator and the like are used. . Although the thickness of the coating film varies depending on the type of the coating solution, the thickness after drying may be in the range of about 0.01 to 100 μm. However, if the thickness is 50 μm or more, cracks are likely to occur in the film. It is preferable to set it to -50 micrometers.

  As a sol-gel method catalyst for polycondensation with a coating solution, a tertiary amine that is substantially insoluble in water and soluble in an organic solvent is used. Specifically, for example, N, N-dimethylbenzylamine, tripropylamine, tributylamine, tripentylamine and the like can be used. In particular, N, N-dimethylbenzylamine is suitable, and 0.01 to 1.0 part by weight, particularly about 0.03 part by weight is used per 100 parts by weight of the total amount of alkoxysilane and silane coupling agent. It is preferable to do.

  Moreover, an acid can also be used as a catalyst of a sol-gel method, for example, mineral acids, such as a sulfuric acid, hydrochloric acid, nitric acid, organic acids, such as an acetic acid and tartaric acid, and others can be used. The amount of the acid used is preferably about 0.001 to 0.05 mol, particularly about 0.01 mol, relative to the total molar amount of alkoxysilane and the alkoxysilane content (for example, silicate moiety) of the silane coupling agent.

  Water contained in the coating solution is added in a proportion of 0.1 to 100 mol, preferably 0.8 to 2 mol, per 1 mol of the total molar amount of the solution alkoxide. Moreover, it is preferable that the polyvinyl alcohol and the ethylene-vinyl alcohol copolymer contained in the coating liquid for forming a gas barrier protective layer are in a state dissolved in a coating liquid containing the above-described alkoxysilane, silane coupling agent, etc. Therefore, an organic solvent may be appropriately selected and added. For example, as the organic solvent, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol and the like can be used.

<Polyester resin film>
As the polyester resin film constituting the laminate of the present invention, a film made of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc. can be used, among these, A film made of polyethylene terephthalate, which is a versatile film, can be preferably used. Moreover, the polyester laminated film in which the surface facing the gas barrier protective layer of the barrier film described above is polyester may be used. Although the thickness of a film can be suitably determined according to a use application, it is about 10-300 micrometers in general.

  Various conventionally known additives such as a light stabilizer, an ultraviolet absorber, an antioxidant, a filler, a lubricant and the like can be appropriately added to the polyester resin film as necessary. Conventionally known light stabilizers and ultraviolet absorbers can be used. For example, phenol-based, phosphorus-based, hindered amine-based light absorbers, benzotriazole-based, benzophenone-based, and salicylic acid ester-based ultraviolet absorbers are used. it can.

<Method for producing laminate>
Next, a method for producing the laminate as described above will be described with reference to the drawings. First, the barrier film 1 and the polyester resin film 2 described above are prepared (FIG. 3 (1)), and either or both of the two films are irradiated with an electron beam (FIG. 3 ( 2)). As a result, as shown in FIG. 3 (3), the barrier film 1 and the polyester resin film 2 are bonded only to the portion irradiated with the electron beam.

  In the present invention, it is preferable to press the laminated films 1 and 2 using a roller 6 or the like as shown in FIG. 4 immediately after irradiating both films or one of the films with an electron beam. Since the surfaces of the films 1 and 2 are uneven at a micro level as shown in FIG. 4, even if the films are overlapped, they are not completely adhered to each other, and the contact area at the contact interface between the two films is small. In this invention, since the contact area in the adhesion surface of both films increases by pressing the films 1 and 2 with the roller 6 etc. immediately after irradiating an electron beam, adhesiveness improves.

  After the barrier film 1 and the polyester resin film 2 are overlaid, when pressing both the films 1 and 2, it is preferable to press both the films 1 and 2 while heating. By pressing while heating, the flexibility of the barrier film 1 and the polyester resin film 2 is improved, and the contact area at the interface (adhesive surface) between the barrier film 1 and the polyester resin film 2 can be further increased. Since it can do, adhesiveness improves more. The heating temperature may be any temperature at which the film can be thermally deformed, although it depends on the type of film to be used. For example, the heating can be performed at a temperature higher than the glass transition temperature of the resin constituting the film. For example, when a polyethylene terephthalate (PET) film is used as the polyester resin film, the heating temperature is 80 to 180 ° C, preferably 100 to 160 ° C. If the heating temperature is too high, the generated radicals are deactivated, and a strong bond cannot be realized. The pressing force (contact pressure) may be increased, and the heating temperature can be lowered by increasing the contact pressure.

  In order to overlap and press the barrier film 1 and the polyester resin film 2, the heat roller 6 or the like can be suitably used as described above. In addition, as shown in FIG. 4, the support roller 7 may be placed at a position facing the heat roller 6 so that the superposed film can be pressed between the heat roller 6 and the support roller 7. . In this way, by placing the support roller 7 at a position facing the heat roller 6, the contact between the laminate (the laminate of the film 1 and the film 2) and the heat roller 6 is brought close to the line contact, and the heat roller 6. It is possible to minimize the deformation that occurs in the laminated body due to the heat from the.

  FIG. 5 is a schematic view showing another embodiment of the manufacturing method according to the present invention. In the process of laminating and adhering the barrier film 1 and the polyester resin film 2, after both the films 1 and 2 are guided to the electron beam irradiation position 3 by the guide rollers, respectively, and both the films 1 and 2 are irradiated. The process of pressing both the films 1 and 2 with the heat roller 6 is performed continuously. Each film 1, 2 may be supplied in roll form.

  When irradiating each film 1 and 2 with the electron beam 4 from the electron beam irradiation apparatus 3, it is preferable to irradiate the electron beam 4 from the film side with smaller thickness. Since the electron beam has the property that its transmission power increases as the acceleration voltage increases, depending on the thickness of the film, the electron beam may reach the other film when irradiated with the electron beam from one of the film sides. May not arrive. In that case, the electron beam can reach the deep part of the other film by increasing the acceleration voltage of the electron beam, but unnecessary irradiation is performed on the film itself as the electron beam energy increases. It will deteriorate. Therefore, when a thick film and a thin film are laminated and bonded, it is preferable to irradiate an electron beam from the thin film side without increasing the electron beam energy so much. For example, when the thickness of the barrier film is 25 μm or less and the thickness of the polyester resin film is 50 μm or more, the electron beam is irradiated from the barrier film 1 side. By adopting such an electron beam irradiation method, deterioration of the film can be minimized.

  When the films 1 and 2 to be overlapped are both thick, another electron is placed at a position facing the electron beam irradiation device 3 so that an electron beam can be irradiated from both film sides as shown in FIG. A line irradiation device 3 ′ may be provided. According to this aspect, since the irradiation energy of an electron beam can be adjusted according to the thickness of a film, both films can be adhere | attached, without deteriorating a film.

  FIG. 6 is a schematic view showing an embodiment of another manufacturing method according to the present invention. In this embodiment, the electron beam irradiation is performed before the barrier film 1 and the polyester resin film 2 are overlapped. First, a pair of supplied films (the barrier film 1 and the polyester resin film 2) are transferred to the film 1 (2) by the electron beam irradiation device 3 (3 ′) before the films 1 and 2 are overlapped. The electron beam 4 (4 ′) is irradiated. In the embodiment shown in FIG. 5, both the films 1 and 2 are overlapped so that the surfaces opposite to the electron beam irradiation side of the films 1 and 2 face each other, whereas in the embodiment shown in FIG. The difference is that the two films 1 and 2 are overlapped so that the surfaces of the two films 1 and 2 on the electron beam irradiation side face each other. Thus, by superimposing the other film 2 on the surface of the film 1 irradiated with the electron beam, the irradiation energy of the electron beam can be made smaller regardless of the thickness of the film. As a result, the film Degradation due to electron beam irradiation can be further reduced.

  Also in the embodiment shown in FIG. 6, a pair of electron beam irradiation devices 3 and 3 ′ are provided, and in the same manner as the embodiment shown in FIG. 5, electrons are transferred to each of the barrier film 1 and the polyester resin film 2. Lines 4 and 4 'may be irradiated. By these combinations, the deterioration of the film can be further reduced and the adhesive strength can be improved.

  FIG. 7 is a schematic view showing another embodiment of the manufacturing method according to the present invention. In this embodiment, the barrier film 1 and the polyester resin film 2 are overlapped and pressed by the heat roller 6 and then irradiated with an electron beam. First, the pair of supplied films 1 and 2 are led to a guide roller and overlapped. Subsequently, both the films 1 and 2 are pressed by the heat roller 6 and the support roller 7, and heating is performed by the heat roller 6. Thereafter, the electron beam irradiation device 3 irradiates the surface of the barrier film 1 and the polyester resin film 2 with the electron beam 4 so that the bonding of the two is continued. In the embodiment shown in FIG. 7, a pair of electron beam irradiation devices 3 and 3 ′ are provided, and the electron beams 4 and 4 are respectively applied to both films 1 and 2 similarly to the embodiment shown in FIGS. 4 'may be irradiated. By these combinations, the deterioration of the film can be further reduced and the adhesive strength can be improved.

  The irradiation energy of the electron beam needs to be appropriately adjusted according to the film thickness and the like as described above. In the present invention, the electron beam is irradiated in an irradiation energy range of about 20 to 750 kV, preferably 25 to 400 kV, and more preferably about 30 to 300 kV. However, the irradiation energy is preferably lower, and 40 to 200 kV. Can do. Thus, by setting it as low irradiation energy, not only deterioration of a film can be suppressed, but since radical generation | occurrence | production of a film surface occurs more efficiently, stronger bond can be implement | achieved. The absorbed dose of the electron beam is 5 to 800 kGy, preferably 25 to 600 kGy.

  As such an electron beam irradiation apparatus, conventionally known ones can be used. For example, a curtain type electron irradiation apparatus (LB1023, manufactured by I. Electron Beam Co., Ltd.) or a line irradiation type low energy electron beam irradiation apparatus (EB-ENGINE). , Manufactured by Hamamatsu Photonics Co., Ltd.) can be preferably used.

  When irradiating with an electron beam, the oxygen concentration is preferably 100 ppm or less. This is because irradiation with an electron beam in the presence of oxygen generates ozone and may adversely affect the environment. In order to reduce the oxygen concentration to 100 ppm or less, the film may be irradiated with an electron beam in a vacuum or in an inert gas atmosphere such as nitrogen or argon. For example, by filling the electron beam irradiation apparatus with nitrogen, A concentration of 100 ppm or less can be achieved.

  The laminate obtained by laminating the barrier film and the polyester resin film obtained by the above-described adhesion method can realize an adhesive strength equal to or higher than that obtained by using a conventional laminate resin. In addition, since no laminate resin or the like is used, foreign matter or residual solvent does not bleed out even when the laminate is used, and the gas barrier property, light shielding property, and strength are excellent.

<Preparation of barrier film>
A biaxially stretched polyethylene terephthalate film having a thickness of 12 μm was used, and a silicon oxide thin film was formed on one surface of the film so as to have a film thickness of 20 nm using a vapor deposition apparatus under the following conditions.
Deposition conditions:
Degree of vacuum in the deposition chamber (after introducing oxygen): 2 × 10 ⁻⁴ mbar
Vacuum degree in the winding chamber: 5 × 10 ⁻³ mbar
Electron beam power: 25kW

Next, a hydrolyzed liquid having the following composition II is added to a mixed liquid containing a polyvinyl alcohol solution having the following composition I, isopropyl alcohol and ion-exchanged water, and the mixture is sufficiently stirred to form a coating solution for forming a gas barrier protective layer. And prepared.
Composition I:
Polyvinyl alcohol 2.33 (mass%)
Isopropyl alcohol 2.70 (mass%)
Water 51.75 (mass%)

Composition II (hydrolyzed solution):
Ethyl silicate 16.60 (mass%)
Silane coupling agent 1.66 (mass%)
Isopropyl alcohol 3.90 (mass%)
0.5N hydrochloric acid aqueous solution 0.53 (mass%)
Water 20.53 (mass%)
Total 100.00 (mass%)

  The above coating solution is coated on the silicon oxide thin film by a gravure roll coating method, and then heat-treated at 180 ° C. for 60 seconds to form a gas barrier protective layer having a thickness of 0.2 μm (dry operation state). Thus, a barrier film 1 was obtained.

  Moreover, it replaced with the silicon oxide thin film and produced the barrier film 2 like the above except having formed the aluminum oxide thin film.

<Preparation of polyester resin film>
A polyester resin film having a thickness of 25 μm (Espet, manufactured by Toyobo Co., Ltd.) was prepared as a polyester resin film.

Example 1
<Production of laminate>
Samples prepared by cutting the prepared barrier film 1 and polyester resin film into a size of 150 mm × 75 mm were prepared, and an electron beam irradiation device (line irradiation type low energy electron beam irradiation device EES-L-DP01, Hamamatsu Photonics Co., Ltd.) Placed side by side on a sample stand. At this time, in order to provide a portion where the sample is not irradiated with the electron beam, masking is performed on one end portion of both samples of about 5 to 10 mm.

Next, after purging with nitrogen gas so that the oxygen concentration in the chamber of the electron irradiation apparatus becomes 100 ppm or less, the surface of the sample was irradiated with an electron beam under the following electron beam irradiation conditions. In addition, about the barrier film, the electron barrier was irradiated to the gas barrier protective layer formation surface.
Voltage: 40 kV
Absorbed dose: 200kGy
In-device oxygen concentration: 100 ppm or less

  After irradiating the electron beam, the sample was taken out from the apparatus and immediately laminated so that the electron beam irradiation surface sides of both films were opposed to each other, and both films were bonded by a thermal laminating method to obtain a laminate.

Example 2
In Example 1, a laminate was obtained in the same manner as in Example 1 except that the electron beam irradiation conditions were changed as shown in Table 1 below.

Example 3
In Example 1, the barrier film 2 was used in place of the barrier film 1, and a laminate was obtained in the same manner as in Example 1 except that the electron beam irradiation conditions and adhesion conditions shown in Table 1 were used.

Comparative Example 1
A laminate was obtained in the same manner as in Example 1 except that electron irradiation was not performed. However, the obtained laminate was not bonded to the barrier film 1 and the polyester resin film.

Comparative Example 2
A laminate was obtained by a dry laminating method in which the two types of resin films used in Example 1 were bonded together via a two-component curable aromatic ester adhesive (Takelac A-3, manufactured by Mitsui Chemicals, Inc.).

<Evaluation of adhesive strength of laminate>
The obtained laminate was cut into a strip shape with a width of 15 mm, and a 90 ° peel test was performed at a rate of 50 mm / min using a tensile tester (Tensilon Universal Material Tester RTC-1310A, manufactured by ORIENTEC). went. As described above, in the laminate of Comparative Example 1, the barrier film 1 and the resin film were not adhered, and the adhesive strength of the laminate could not be measured. The evaluation results were as shown in Table 1 below.

  In addition, in order to indirectly check whether the adhesion of the laminates of Examples 1 to 3 is due to a covalent bond, the obtained laminate was stored in water, and then the adhesive strength of the laminate in the same manner as described above. Was measured. The evaluation results were as shown in Table 1 below.

  As is clear from the evaluation results in Table 1, the laminates of Examples 1 to 3 maintain adhesiveness even after storage in water. From this result, it can be seen that in the laminates of Examples 1 to 3, the barrier film and the polyester resin film are not bonded only by hydrogen bonding or intermolecular force. Therefore, although indirectly, it can be inferred that a covalent bond is formed between the atoms in the gas barrier protective layer of the barrier film and the atoms in the polyester resin film. It has the same adhesive strength as the laminate.

DESCRIPTION OF SYMBOLS 1 Barrier film 11 Thermoplastic resin film 12 Thin film layer 13 Gas barrier property protective layer 2 Polyester resin film 3, 3 'Electron beam irradiation apparatus 4, 4' Electron beam 5 Film base material contact interface 6 Heat roller 7 Support roller

Claims (9)

A barrier film comprising a thermoplastic resin film, a thin film layer made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film, and a gas barrier protective layer provided on the thin film layer; and polyester The resin film is a laminated body laminated so that the gas barrier protective layer of the barrier film and the polyester resin film face each other,
The gas barrier protective layer comprises a film obtained by applying a solution containing at least a water-soluble polymer having a hydroxyl group and alkoxysilane,
In at least a part of the interface between the gas barrier protective layer and the polyester resin film, a bond is formed between an atom in the gas barrier protective layer and an atom in the polyester resin film, and the gas barrier property A laminate comprising a protective layer and the polyester resin film bonded to each other without an adhesive.   At least part of the interface between the gas barrier protective layer and the polyester resin film, between an atom in the gas barrier protective layer and an atom in the polyester resin film, via an oxygen atom, a nitrogen atom or a hydroxyl group The laminate according to claim 1, wherein a bond is formed. The alkoxysilane is represented by the following general formula:
R _1n Si (OR ₂ ) _m
(In the formula, R ₁ and R ₂ each independently represent an organic group having 1 to 8 carbon atoms, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents an Si atom. Represents the value.)
The laminated body of Claim 1 or 2 represented by these.   The water-soluble polymer having a hydroxyl group is selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, and an ethylene-vinyl alcohol copolymer, or a mixture of two or more. The laminate according to any one of claims 1 to 3, wherein   The laminated body as described in any one of Claims 1-4 whose said polyester resin film is a polyethylene terephthalate film. A method for producing a laminate obtained by laminating a barrier film and a polyester resin film according to any one of claims 1 to 5,
Gas barrier property of a barrier film comprising a thermoplastic resin film, a thin film layer made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film, and a gas barrier protective layer provided on the thin film layer Irradiating the protective layer surface and / or at least one surface of the polyester resin film with an electron beam,
A method comprising superimposing and adhering the gas barrier protective layer surface and / or the polyester resin film surface irradiated with the electron beam.   The method according to claim 6, wherein the electron beam irradiation is performed before and / or after the barrier film and the polyester resin film are overlapped.   The method according to claim 6 or 7, wherein the adhesion is performed under pressure.   The method according to claim 6, wherein the adhesion is performed by heating.

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