JP2012139888A - Laminated body and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated body which prevents the leaking of foreign substances and residual solvent and the like, and exhibits excellent gas barrier property, chemical resistance and aroma retention property.SOLUTION: The laminated body is obtained by piling up a thermoplastic resin film, a laminated film, which includes a membraneous layer comprising an aluminum oxide or a silicon oxide formed on at least one surface of the thermoplastic resin film and a gas barrier protective layer formed on the membraneous layer, and a polyacrylonitrile resin film so that the gas barrier protective layer and the polyacrylonitrile resin film are piled up to face with each other. The gas barrier protective layer includes a coating including a water soluble polymer compound having at least a hydroxyl group and alkoxysilane, wherein bond is formed between atoms in the gas barrier protective layer and atoms in the polyacrylonitrile resin film, allowing the gas barrier protective layer to be adhered to the polyacrylonitrile resin film with no adhesive agent.

Description

  The present invention relates to a laminate, and more specifically, a thermoplastic resin film, a laminate film provided with a thin film layer made of aluminum oxide or silicon oxide, and a gas barrier protective layer in this order are bonded to a polyacrylonitrile resin film. The present invention relates to a laminated body bonded without using an agent 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. For example, in order to prevent deterioration of the contents due to ultraviolet rays, etc., a film having an ultraviolet absorption function is used, or in order to prevent the contents from being altered by oxygen, a gas-impermeable film or oxygen absorption is used. A film having a function is used.

  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.

  Since heat sealing does not use a laminate resin or the like when bonding the films, the films can be bonded easily and simply. However, the heat sealing process is a method in which the films are partially melted or semi-melted, and the films are bonded to each other, so that different films, for example, a polyolefin film and a polyester film are bonded to each other. It cannot be bonded by heat sealing. In addition, in heat seal processing, it is necessary to use a film made of a resin that can be fused at a relatively low temperature. Therefore, a multilayer film in which a heat sealable resin layer such as polyolefin resin is provided on the outermost surface layer is used. (For example, JP-A-55-107428).

  On the other hand, when films are bonded together by laminating, the components of the laminating resin are appropriately selected according to the type of film to be used (type of resin). For example, when processing into a bag shape by bonding a polyester film and a nylon film, a urethane adhesive has been used (for example, JP-A-52-82594).

  However, 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, and the contents may be altered. In the medical field where cleanliness is important, contamination of the contents by the laminate resin may be 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 3) 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-A-55-107428 JP 52-82594 A 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

  The present inventors are now able to firmly adhere to each other without using a laminate resin or the like by irradiating the film with an electron beam even when films made of different materials are adhered to each other. I found it. And even if it is a laminate that has been conventionally bonded to each other with an adhesive, such as a laminate of a laminated film including a gas barrier protective layer and a polyacrylonitrile resin film, according to electron beam irradiation, the adhesive Even if it is not used, the knowledge that a covalent bond or a hydrogen bond was formed between the atom by the side of a lamination | stacking film and the atom by the side of a polyacrylonitrile resin film, and it mutually adhere | attached was acquired. The present invention is based on this finding.

  Therefore, the object of the present invention is a laminate in which a laminated film including a gas barrier protective layer and a polyacrylonitrile resin film are bonded without using an adhesive, and foreign matter, residual solvent, and the like are not leached. And it is providing the laminated body excellent also in gas-barrier property, chemical-resistance, and aroma retention.

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. The laminated film and the polyacrylonitrile resin film are laminated so that the gas barrier protective layer and the polyacrylonitrile resin film are opposed to 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 gas barrier protective layer and the polyacrylonitrile resin film, a covalent bond is formed between an atom in the gas barrier protective layer and an atom in the polyacrylonitrile resin film, and the gas barrier property The protective layer and the polyacrylonitrile resin film are bonded without using an adhesive.

  Further, as an aspect of the present invention, an oxygen atom or a hydroxyl group is covalently bonded to a carbon atom in the polyacrylonitrile resin film, and the oxygen atom and / or hydroxyl group in the gas barrier protective layer and the polyacrylonitrile resin film It is preferable that a hydrogen bond is formed between the oxygen atom or the hydroxyl group therein.

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 to be represented by

  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 thermoplastic 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 laminate film and a polyacrylonitrile resin film are laminated,
Gas barrier protection of a laminated 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 layer surface and / or at least one surface of the polyacrylonitrile resin film with an electron beam,
The gas barrier protective layer surface irradiated with the electron beam of the laminated film and the polyacrylonitrile resin film surface are superposed and bonded together.

  As an aspect of the present invention, it is preferable to perform electron beam irradiation before and / or after the laminated film and the polyacrylonitrile resin film are overlaid.

  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. Since covalent bonds and / or hydrogen bonds are formed between the atoms in the laminated film and the atoms in the polyacrylonitrile resin film, the laminated film and the polyacrylonitrile resin can be used without being bonded via an adhesive. A laminate in which the film is 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, chemical resistance, and aroma retention.

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 1 according to the present invention has a structure in which a laminate film 20 and a polyacrylonitrile resin film 10 are laminated without using an adhesive. The laminated film 20 includes a thermoplastic resin film 21, a thin film layer 22 made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film 20, and a gas barrier protective layer 23 provided on the thin film layer 22. .

  The gas barrier protective layer 23 corresponding to the adhesive surface of the laminated film 20 with the polyacrylonitrile resin film 10 is made of a coating obtained by applying a solution containing at least a water-soluble polymer having a hydroxyl group and alkoxysilane. In the present invention, a laminated film and a polyacrylonitrile resin film are formed by forming a covalent bond between an atom in the gas barrier protective layer and an atom in the polyacrylonitrile resin film on at least a part of the adhesive surface. Are firmly bonded. Usually, the surface of the gas barrier protective layer obtained by applying a solution containing a water-soluble polymer having a hydroxyl group such as polyvinyl alcohol and alkoxysilane is hydrophilic, while the surface of the polyacrylonitrile resin film is hydrophobic. Therefore, it is usually impossible to bond the two without using an adhesive. In the present invention, as will be described later, the surface of the gas barrier protective layer and / or the polyacrylonitrile resin film is irradiated with an electron beam to generate radicals. And the atom in the polyacrylonitrile resin film 10 form a covalent bond, and the laminated film 20 and the polyacrylonitrile resin film 10 are firmly bonded without using an adhesive. 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.

  The fact that a covalent bond is formed between atoms between the laminated film and the polyacrylonitrile resin film means that an X-ray photoelectron analyzer (hereinafter also referred to as XPS) and a Fourier transform infrared spectrometer (hereinafter also referred to as FTIR). Can be confirmed. For example, before bonding the laminated film and the polyacrylonitrile resin film, by measuring the surface condition of each film by XPS, confirm what atoms exist on the surface of each film before bonding. Then, both films were bonded by electron beam irradiation to form a laminate, and the laminate was forcibly separated to separate it into a laminate film and a polyacrylonitrile resin film, and the surface state of each film was again measured by XPS. Then, what atoms are present on the surface of each film is confirmed. As a result, by confirming that there is an atom derived from the polyacrylonitrile resin film on the laminated film side or an atom derived from the laminated film on the polyacrylonitrile resin film side, a covalent bond is formed between both films. You can check whether Moreover, you may confirm whether a CN bond exists in the surface by the side of the laminated | multilayer film after peeling using FTIR.

  Moreover, the laminated body which adhere | attached the laminated | multilayer film 20 and the polyacrylonitrile resin film 10 by electron beam irradiation has an oxygen atom or a hydroxyl group covalently bonded to the carbon atom in a polyacrylonitrile resin film, as shown in FIG. Hydrogen bonds are formed between oxygen atoms and / or hydroxyl groups in the gas barrier protective layer 23 and oxygen atoms or hydroxyl groups in the polyacrylonitrile resin film 10. The laminate according to the present invention is such that the laminate film and the polyacrylonitrile resin film are bonded to each other by such a hydrogen bond or the above-described covalent bond, so that the laminate does not peel even if no adhesive is used. It can be. 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 only by hydrogen bonds, when the laminate is immersed in water or an alcohol solution, hydrogen bonds formed between the atoms of both films are broken, and hydrogen atoms or oxygen of water or alcohol Since the atoms and hydrogen bonds are re-formed, the adhesive force is lost and both films are peeled off.

  Hereinafter, the laminated film and the polyacrylonitrile resin film constituting the laminated body according to the present invention will be described.

<Laminated film>
As shown in FIG. 1, the laminated film 20 is provided on the thermoplastic resin film 21, the thin film layer 22 made of aluminum oxide or silicon oxide provided on at least one surface of the thermoplastic resin film 21, and the thin film layer 22. A gas barrier protective layer 23 is included. Although the laminated film 20 is not shown, the thin film layer 22 and the gas barrier protective layer 23 may be provided not only on one surface of the thermoplastic resin film 21 but also on both surfaces thereof.

  In the laminated film 20 used in the laminate according to the present invention, the thin film layer 22 and the gas barrier protective film 23 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 22 and the gas barrier protective layer 23 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. In addition, the silicon oxide thin film is 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 laminated 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.

<Polyacrylonitrile resin film>
The polyacrylonitrile resin film used in the laminate of the present invention has performances excellent in oxygen impermeability, chemical resistance, fragrance retention and the like. The polyacrylonitrile resin may be not only an acrylonitrile homopolymer but also a copolymer obtained by copolymerizing one or more compounds copolymerizable with acrylonitrile. Such a compound is not particularly limited, and examples thereof include rubber components such as nitrile rubber (NBR), acrylic acid esters such as methyl acrylate and ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Examples include methacrylic acid esters, haloolefins such as vinyl chloride, vinyl fluoride, and vinylidene chloride, vinylamides such as acrylamide and vinylpyrrolidone, vinyl aromatic compounds such as styrene, vinyl carboxylic acids, and vinyl sulfonic acids. The proportion of the compound to be copolymerized is preferably 30 mol% or less, and more preferably 15 mol% or less.

  In the present invention, the thickness of the laminated polyacrylonitrile resin film is approximately 20 to 300 μm.

  The laminated body in which the laminated film and the polyacrylonitrile resin film as described above are bonded to each other does not exude foreign matter or residual solvent even when the laminated body is used, and has gas barrier properties and chemical resistance. In addition, it has excellent fragrance retention and heat sealability. Therefore, it can be suitably used for a package used in the medical field, for example, a syringe package bag or a package for filling and packaging a powder or granular pharmaceutical product, not to mention the food field.

<Method for producing laminate>
Next, a method for producing the laminate as described above will be described with reference to the drawings. First, the laminated film 20 and the polyacrylonitrile resin film 10 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), only the portions irradiated with the electron beam are bonded to each other.

  In the present invention, it is preferable to press the stacked films 10 and 20 using a roller 6 or the like as shown in FIG. 4 immediately after irradiating the film with an electron beam. Since the surfaces of the films 10 and 20 are uneven at the 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 films is small. In this invention, since the contact area in the adhesive surface of both films increases by pressing the films 10 and 20 with the roller 6 etc. immediately after irradiating an electron beam, adhesiveness improves.

  After the laminated film 20 and the polyacrylonitrile resin film 20 are overlapped, when the laminated body 1 is pressed, it is preferable to press both the films 10 and 20 while heating. By pressing while heating, the flexibility of the films 10 and 20 is improved, and the contact area at the interface (adhesion surface) of the films 10 and 20 can be further increased, so that the adhesion is further improved. 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 laminated film based on polyethylene terephthalate and a polyacrylonitrile resin film are overlaid, the heating temperature is 80 to 180 ° C, preferably 130 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 press the laminated body 1 which laminated | stacked the laminated | multilayer film 20 and the polyacrylonitrile resin film 10, the heat roller 6 grade | etc., Can be used conveniently as mentioned above. Further, 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 laminated body (10, 20) and the heat roller 6 is brought close to the line contact, and the heat roller 6 is laminated by heat. Deformation occurring in the body (10, 20) can be minimized.

  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 laminated film 20 and the polyacrylonitrile resin film 10, each film 10, 20 is guided to the electron beam irradiation position 3 by a guide roller, and after both the films 10, 20 are irradiated with the electron beam 4 The process of pressing the films 10 and 20 with the heat roller 6 is continuously performed. Each film 10, 20 may be supplied in roll form.

  When irradiating each film 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 a 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 laminated film is 25 μm or less and the thickness of the polyacrylonitrile resin film is 50 μm or more, the electron beam is irradiated from the laminated film side. By adopting such an electron beam irradiation method, deterioration of the film can be minimized.

  When the films 10 and 20 to be superimposed 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 laminated film 20 and the polyacrylonitrile resin film 10 are overlaid. First, a pair of supplied films (laminated film 20 and polyacrylonitrile resin film 10) are transferred to film 10 (20) by electron beam irradiation device 3 (3 ′) before both films 10 and 20 are overlaid. The electron beam 4 (4 ′) is irradiated. In the embodiment shown in FIG. 7, both the films 10 and 20 are overlapped so that the surfaces opposite to the electron beam irradiation side of the films 10 and 20 face each other, whereas in the embodiment shown in FIG. The difference is that the films 10 and 20 are overlapped so that the surfaces of the films 10 and 20 on the electron beam irradiation side face each other. Thus, by superimposing the other film 20 on the surface of the film 10 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.

  In the embodiment shown in FIG. 6, a pair of electron beam irradiation devices 3 and 3 ′ are provided, and electrons are respectively applied to the laminated film 20 and the polyacrylonitrile resin film 10 as in the embodiment shown in FIG. 5. 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 laminated film 20 and the polyacrylonitrile resin film 10 are overlapped and pressed by the heat roller 6 and then irradiated with an electron beam. First, the pair of supplied films 10 and 20 are led to a guide roller and overlapped. Subsequently, both the films 10 and 20 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 surfaces of the films 10 and 20 with the electron beam 4 so that the films 10 and 20 are continuously bonded. In the embodiment shown in FIG. 7, a pair of electron beam irradiation devices 3 and 3 ′ are provided, and both the electron beams 4 and 20 are respectively applied to both films 10 and 20 similarly to the embodiment shown in FIGS. 5 and 6. 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 10 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 laminated body obtained by laminating the laminated film and the polyacrylonitrile 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 laminated resin. In addition, since no laminate resin or the like is used, foreign matter or residual solvent does not ooze out when using a laminate, and gas barrier properties, chemical resistance, and fragrance retention are excellent. .

<Preparation of film>
Using a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, an aluminum 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 liquid is coated on the aluminum 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). As a result, a laminated film was obtained.

  In addition, a polyacrylonitrile resin film (Hitron BX, manufactured by Tamapoly) having a thickness of 30 μm was prepared as a polyacrylonitrile resin film.

Example 1
<Production of laminate>
Samples obtained by cutting each of the above-mentioned two types of films into a size of 150 mm × 75 mm were prepared, and an electron beam irradiation apparatus (line irradiation type low energy electron beam irradiation apparatus EES-L-DP01, manufactured by Hamamatsu Photonics Co., Ltd.) It was placed side by side on the sample stage. 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.
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.

Examples 2 and 3
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.

Comparative Example 1
A laminate was obtained in the same manner as in Example 1 except that electron irradiation was not performed. However, in the obtained laminate, the laminate film and the polyacrylonitrile resin film were not adhered.

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.). However, in the obtained laminate, the laminate film and the polyacrylonitrile resin film were not adhered.

<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. Note that, as described above, in the laminate of Comparative Example 1, the laminate film and the polyacrylonitrile resin film were not adhered, and the adhesion 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 laminate of Example 1 is due to a covalent bond, the obtained laminate was stored in water, and then the adhesion strength of the laminate was measured in the same manner as described above. did. The evaluation results were as shown in Table 1 below.

  As is clear from the evaluation results in Table 1, the laminate of Example 1 has the same adhesive strength as that measured in air even after storage in water. From this result, it can be seen that in the laminate of Example 1, the laminate film and the polyacrylonitrile resin film are not bonded only by hydrogen bonds or intermolecular forces. Therefore, although indirectly, it can be inferred that a covalent bond is formed between the silicon atom of the laminated film and the carbon atom of the polyacrylonitrile resin film, which is about the same as a conventional laminated body laminated with an adhesive. It has the adhesive strength.

DESCRIPTION OF SYMBOLS 1 Laminated body 10 Polyacrylonitrile resin film 20 Laminated film 21 Thermoplastic resin film 22 Thin film layer 23 Gas barrier property protective layer 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 laminated 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 polyacrylonitrile The resin film is a laminate in which the gas barrier protective layer and the polyacrylonitrile resin film are laminated so as to 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 gas barrier protective layer and the polyacrylonitrile resin film, a covalent bond is formed between an atom in the gas barrier protective layer and an atom in the polyacrylonitrile resin film, and the gas barrier property A laminate, wherein the protective layer and the polyacrylonitrile resin film are bonded without using an adhesive.   An oxygen atom or a hydroxyl group is covalently bonded to a carbon atom in the polyacrylonitrile resin film, and an oxygen atom and / or a hydroxyl group in the gas barrier protective layer and an oxygen atom or a hydroxyl group in the polyacrylonitrile resin film The laminated body of Claim 1 in which the hydrogen bond is formed between. 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 thermoplastic resin film is a polyethylene terephthalate film. A method for producing a laminate in which a laminate film and a polyacrylonitrile resin film according to any one of claims 1 to 5 are laminated,
Gas barrier protection of a laminated 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 layer surface and / or at least one surface of the polyacrylonitrile resin film with an electron beam,
A method comprising: superposing and adhering a gas barrier protective layer surface irradiated with an electron beam of the laminated film and the polyacrylonitrile resin film surface.   The method according to claim 6, wherein the electron beam irradiation is performed before and / or before superposing the laminated film and the polyacrylonitrile resin film.   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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