Laminated film

[Field of Use] The present invention relates to a laminated film having excellent gas barrier properties.

[0002] [Conventional Technology] Although various functions required for packaging are wide-ranging, various gas barrier properties as content protection are important properties that affect the storage stability of foods, and diversification of distribution forms and packaging technologies. The need for it is increasing due to the regulation of additives and changes in taste. The gas barrier property was also a weak point of general plastic materials. Examples of food deterioration factors include oxygen, light, heat, and moisture, and oxygen is particularly important as a causative substance thereof. The barrier material is an indispensable material for means to effectively block oxygen and at the same time control the deterioration of food such as gas filling and vacuum packaging. Not only oxygen gas but also various gases, organic solvent steam, aroma, etc. By having a barrier function, it can be used for rust prevention, deodorization, and sublimation prevention, and is used in many fields such as foods such as confectionery bags, bonito packs, retort pouches, and carbon dioxide gas beverage containers, cosmetics, pesticides, and medical care. ..

[0003] Among films made of thermoplastic resins, particularly oriented films such as polypropylene, polyester, and polyamide have excellent mechanical properties, heat resistance, transparency, and the like, and are widely used as packaging materials. There is. However, when these films are used for food packaging, the blocking properties of oxygen and other gases are insufficient, so that they are liable to cause oxidative deterioration and alteration of the contents by aerobic microorganisms, and aroma components permeate. This tends to cause various problems such as loss of flavor and moistening of the contents by the moisture of the outside world, which makes the mouthfeel unpleasant. Therefore, in many cases, a method such as laminating another film layer having a good gas barrier property is usually taken.

[0004] As a method for developing gas barrier properties, there is a method for dispersing a flat-form inorganic substance in a resin. For example, Japanese Patent Application Laid-Open No. 62-148532 describes a concentration of 1,6-hexanepolycarbonatediol at a concentration of 30. A coating liquid composition consisting of 25 parts by weight of mica fine powder and 60 parts by weight of dimethylformamide on 100 parts by weight of a polyurethane resin solution of% is coated on a releasable base material, dried, and then peeled off from the base material. The method is described. Further, in Japanese Patent Application Laid-Open No. 64-043554, an aqueous methanol solution of an ethylene / vinyl alcohol copolymer has an average length of 7 μm and an aspect ratio of 140. A method is described in which mica is added and injected into cold water to precipitate, filter, dry, pelletize, and then obtain a film. Further, in Japanese Patent Application Laid-Open No. 3-93542, a coating composition in which a silyl group-containing modified polyvinyl alcohol and synthetic hectorite have a weight ratio of 50:50 is applied onto biaxially stretched polyethylene terephthalate (OPET). A method of drying and heat treating (130 to 150 ° C) is described. However, the films obtained by these techniques are not yet sufficient in terms of gas barrier properties, and it cannot be said that they are always satisfactory.

[0005] Conventionally, as one of the important means for imparting gas barrier properties, a metal such as aluminum or an oxide such as silica or alumina is vapor-deposited on at least one of the films made of a thermoplastic resin. A method of forming a thin film and imparting a barrier property is known. However, there is a problem that pinholes are likely to occur in the process of thin film formation and the performance is greatly deteriorated due to the deformation of the film due to the lack of flexibility and mechanical strength of the thin film. It is not always satisfactory.

[0006] An object of the present invention is to provide a gas barrier molded article or film having a high level of gas barrier property.

[Means for Solving the Problems] As a result of diligent studies to solve the above problems, the present inventors have made a film in which a layer made of an inorganic layered compound and a resin is laminated on a metal or oxide thin film. We have found that a remarkably excellent gas barrier property is exhibited, and have arrived at the present invention.

[0008] The present invention includes an inorganic layered compound having a particle size of 5 μm or less and an aspect ratio of 50 or more and 5000 or less and a resin on a thin film layer of a metal or oxide formed on at least one surface of a resin film. The present invention relates to a laminated film formed by laminating at least one layer made of a resin composition characterized by the above. ..

[0009] The inorganic layered compound used in the present invention refers to an inorganic compound having a layered structure in which unit crystal layers are stacked on each other. In other words, the "layered compound" is a compound or substance having a layered structure, and the "layered structure" is a surface in which atoms are strongly bonded by covalent bonds or the like and are densely arranged, such as van der Waals force. It is a structure that is stacked in parallel due to the weak coupling force of. The "inorganic layered compound" that can be used in the present invention is not particularly limited as long as the aspect ratio measured by the method described later is 50 or more and 5000 or less and the particle size is 5 μm or less. From the viewpoint of gas barrier property, the aspect ratio is preferably 100 or more (particularly 200 or more). If the aspect ratio is less than 50, the expression of gas barrier property is insufficient. On the other hand, it is technically difficult to obtain an inorganic layered compound having an aspect ratio of more than 5000, and it is costly or economically expensive. From the viewpoint of ease of manufacture, this aspect ratio is preferably 2000 or less (further 1500 or less). From the viewpoint of the balance between gas barrier property and ease of manufacture, this aspect ratio is more preferably in the range of 200 to 3000. From the viewpoint of film-forming property or moldability when formed into a film, the "particle size" measured by the method described later is preferably 5 μm or less. If this particle size exceeds 5 μm, the film-forming property or moldability of the resin composition tends to decrease. From the viewpoint of transparency of the resin composition, this particle size is preferably 3 μm or less. When the film of the present invention is used in applications where transparency is important (for example, food applications), the particle size is particularly preferably 1 μm or less. Further, this transparency is preferably about 80% or more (further, 85% or more) in the total light transmittance at a wavelength of 500 nm. Such transparency can be suitably measured by, for example, a commercially available spectrophotometer (manufactured by Hitachi, Ltd., self-recording spectrophotometer 330 type). Specific examples of the inorganic layered compound include graphite, phosphate-based derivative compound (zirconium phosphate-based compound), chalcogenide [Group IV (Ti, Zr, Hf), Group V (V, Nb, Ta) and VI. It is a group (Mo, W) dicalcogenate, and the formula MX₂ It is represented by. Here, X indicates chalcogen (S, Se, Te). ],<u style="single">Clay minerals</u>And so on.

[0010] Since it is extremely difficult to measure the true particle size in the resin composition, the particle size of the inorganic layered compound used in the present invention is a value obtained by a dynamic light scattering method in a solvent. When sufficiently swollen with a solvent of the same type as the solvent used in the dynamic light scattering method and composited with the resin, the particle size of the inorganic layered compound in the resin can be considered to be close to the particle size in the solvent.

[0011] The aspect ratio (Z) of the inorganic layered compound used in the present invention is indicated by the relationship Z = L / a. [L is the particle size obtained by dynamic light scattering in a solvent, and a is the unit thickness of the inorganic layered compound (unit thickness a is the measurement of the inorganic layered compound alone by powder X-ray diffraction method or the like. It is a value determined by.)]. However, at Z = L / a, there is a plane spacing d obtained from the powder X-ray diffraction of the composition, and the relationship a &lt;d is satisfied. Here, it is necessary that the value of da is larger than the width of the resin single chain in the composition. Z is not necessarily the true aspect ratio of the inorganic layered compound in the resin composition, but it is quite valid for the following reasons.

[0012] The aspect ratio of the inorganic layered compound in the resin composition is extremely difficult to measure directly. There is a relationship a &lt;d between the interplanar spacing d obtained by the powder X-ray diffraction method of the composition and the unit thickness a determined by the powder X-ray diffraction measurement of the inorganic layered compound alone, and the value of da is the composition. If it is equal to or larger than the width of the single chain of the resin inside, it means that the resin is inserted between the layers of the inorganic layered compound in the resin composition, and therefore the thickness of the inorganic layered compound is a unit thickness a. Is clear. Further, although it is extremely difficult to measure the true particle size in the resin composition, considering the case where the solvent is sufficiently swollen with the same solvent as the solvent used in the dynamic light scattering method and compounded with the resin, the resin is contained. It can be considered that the particle size of the inorganic layered compound in the above is considerably close to that in the solvent (however, the particle size L obtained by the dynamic light scattering method does not exceed the major axis Lmax of the inorganic layered compound. Therefore, it is theoretically impossible for the true aspect ratio Lmax / a to fall below the definition Z of the aspect ratio in the present invention). From the above two points, it is considered that the definition of the aspect ratio of the present invention is relatively valid. In the present invention, the aspect ratio or particle size means the aspect ratio or particle size defined above. For details on how to obtain a and d, refer to, for example, Shuichi Iwao et al., Clay Encyclopedia, pages 35 and below and 271 and below, 1985, Asakura Shoten Co., Ltd. (Furthermore, Figure). See 5-11). The width of the single resin chain in the composition can be obtained by simulation calculation, etc. (see, for example, Okamura et al., Introduction to Polymer Chemistry, pp. 103-110, 1981, Kagaku-Dojin). In the case of alcohol, it is 4 to 5 angstroms (in the case of water molecules, it is 2 to 3 angstroms). In this way, the integrated intensity of the diffraction peaks (corresponding to the surface spacing d) observed in the powder X-ray diffraction of the resin composition is 2 or more as a relative ratio to the integrated intensity of the reference diffraction peak (corresponding to the surface spacing a). (Furthermore, 10 or more) is preferable. FIG. 5 is a graph schematically showing the relationship between the X-ray diffraction peak of the inorganic layered compound and the unit thickness a of the compound. FIG. 6 is a graph schematically showing the relationship between the X-ray diffraction peak of the resin composition containing the inorganic layered compound and the plane spacing d of the composition. FIG. 7 shows the relationship between the X-ray diffraction peak of the resin composition and the surface spacing d of the composition when the peak corresponding to the surface spacing d overlaps with the halo (or background) and is difficult to detect. It is a graph which shows typically. In this figure, 2θd The area of the portion excluding the baseline on the lower angle side is the peak corresponding to the surface spacing d (θd is the diffraction angle corresponding to "unit thickness a + width of resin single chain"). FIG. 8 is a graph showing the X-ray diffraction peak of the polyvinyl alcohol PVA117H / Kunipia F composition and a graph showing the X-ray diffraction peak of Kunipia F (montmorillonite). FIG. 9 is a graph showing the X-ray diffraction peak (pattern of FIG. 6) of the composition having a plane spacing d = 19.62 angstrom. FIG. 10 is a graph showing the X-ray diffraction peaks (patterns of FIGS. 6 and 7) of the composition having a plane spacing of d = 32.94 angstroms. FIG. 11 is a graph showing the X-ray diffraction peaks (pattern of FIG. 7) of the composition having a plane spacing d of 44.13 angstroms or more.

[0013] As an inorganic layered compound having a large aspect ratio, it swells in a solvent.<u style="single">and</u>Cleavable inorganic layered compounds are preferably used. "Swelling" of the inorganic layered compound used in the present invention into a solvent<u style="single">and</u>The degree of cleavage is as follows<u style="single">Swelling test and cleavage test</u>Can be evaluated by. The swellability of the inorganic layered compound is preferably about 5 or more (further, about 20 or more) in the swellability test described below. On the other hand, the cleavage property of the inorganic layered compound is preferably about 5 or more (further, about 20 or more) in the cleavage property test below. In these cases, as the solvent, a solvent having a density smaller than the density of the inorganic layered compound is used. When the inorganic layered compound is a natural swellable clay mineral, it is preferable to use water as the solvent. &lt;Swellability test&gt;: Slowly add 2 g of the inorganic layered compound to 100 mL of the solvent (using a 100 mL graduated cylinder as a container). Read the volume of the former (inorganic layered compound dispersion layer) from the scale of the interface between the inorganic layered compound dispersion layer and the supernatant 24 hours after mixing and standing at 23 ° C. The larger this value, the higher the swelling property. &lt;Cleavage test&gt;: Slowly add 30 g of the inorganic layered compound to 1500 mL of the solvent, and use a disperser (manufactured by Asada Iron Works Co., Ltd., Desper MH-L, blade diameter 52 mm, rotation speed 3100 rpm, container capacity 3 L, bottom-blade distance 28 mm) to achieve peripheral speed. After dispersing at 8.5 m / sec for 90 minutes (23 ° C), take 100 mL of the dispersion, put it in a 100 mL graduated cylinder and let stand for 60 minutes, then read the volume of the inorganic layered compound dispersion layer from the scale at the interface with the supernatant. The larger this value, the higher the cleavage. Swelling in solvent<u style="single">and</u>As an inorganic layered compound that cleaves, it swells in a solvent.<u style="single">and</u>Cleavable clay minerals can be preferably used.<u style="single">Clay minerals</u>Is generally a type consisting of a two-layer structure having an octahedral layer with aluminum, magnesium, etc. as the central metal above the tetrahedral layer of silica, and a tetrahedral layer of silica with aluminum, magnesium, etc. as the central metal. It is classified into a type consisting of a three-layer structure in which the octahedral layer is sandwiched from both sides. Examples of the former include kaolinites and antigolites, and examples of the latter include smectites, vermiculites and mica depending on the number of interlayer cations. Specifically, kaolinite, dickite, chlorite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, hectorite, tetrasilic mica, sodium teniolite, muscovite, margarite, talc, vermiculite, phlogopite. , Phlogopite, chlorite, etc.

[0014] The solvent for swelling the inorganic layered compound is not particularly limited, and examples thereof include water, alcohols such as methanol, dimethylformamide, dimethyl sulfoxide, and acetone in the case of natural swellable clay minerals, and water and Alcohols such as methanol are more preferred.

[0015] The resin used in the present invention is not particularly limited, and is, for example, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), and polysaccharides. , Polyacrylic acid and its esters and the like.

[0016] A preferred example is a highly hydrogen-bonding resin in which the weight percentage of the hydrogen-bonding group or the ionic group per unit weight of the resin satisfies a ratio of 20% to 60%. A more preferable example is one in which the weight percentage of the hydrogen-bonding group or the ionic group per unit weight of the high-hydrogen-bonding resin satisfies the ratio of 30% to 50%. Examples of the hydrogen-bonding group of the high hydrogen-bonding resin include a hydroxyl group, an amino group, a thiol group, a carboxyl group, a sulfonic acid group and a phosphoric acid group, and examples of the ionic group include a carboxylate group, a sulfonic acid ionic group and a phosphoric acid. Examples thereof include an ionic group, an ammonium group and a phosphonium group. Among the hydrogen-bonding groups or ionic groups of the high hydrogen-bonding resin, more preferable ones include a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonic acid ion group, an ammonium group and the like. Be done.

[0017] Specific examples include, for example, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 41 mol% or more, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, amylose, amylopectin, pullulan, curdran, and zantane. , Polysaccharides such as chitosan, chitosan, cellulose, pullulan, chitosan, polyacrylic acid, sodium polyacrylate, polybenzenesulfonic acid, sodium polybenzenesulfonate, polyethyleneimine, polyallylamine, its ammonium salt polyvinylthiol, poly Glycerin, etc. can be mentioned.

[0018] Further preferable of the highly hydrogen-bonding resin are polyvinyl alcohol and polysaccharides. The polyvinyl alcohol used in the inorganic layered compound-containing layer of the present invention is a polymer having a monomer unit of vinyl alcohol as a main component. Such "polyvinyl alcohol" is, for example, a polymer obtained by hydrolyzing or exchanging (saponking) the acetate portion of a vinyl acetate polymer (to be exact, a copolymer of vinyl alcohol and vinyl acetate). , A polymer obtained by saponifying a trifluorovinyl acetate polymer, a vinyl formate polymer, a vinyl pivalate polymer, a t-butyl vinyl ether polymer, a trimethylsilyl vinyl ether polymer, etc. (of "polyvinyl alcohol"). For details, see, for example, Poval Society, "The World of PVA", 1992, Polymer Publishing Association; Nagano et al., Poval, 1981, Polymer Publishing Association Co., Ltd.). The degree of "saponification" in polyvinyl alcohol is preferably 70% or more in molar percentage, more preferably 85% or more, and even more preferably 98% or more so-called completely saponified products. The degree of polymerization is preferably 100 or more and 5000 or less (further, 200 or more and 3000 or less is preferable).

[0019] The polysaccharide referred to here is a biopolymer synthesized in a biological system by polycondensation of various monosaccharides, and here, a chemical modification based on them is also included. For example, cellulose and cellulose derivatives such as hydroxymethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose, amylose, amylopectin, pullulan, curdlan, zantane, chitin, chitosan and the like can be mentioned.

[0020] When the resin used in the present invention is a high hydrogen-bonding resin, a hydrogen-bonding group cross-linking agent may be used for the purpose of improving its water resistance (meaning of barrier property after water resistance environment test). it can.

[0021] The cross-linking agent for a hydrogen-bonding group is not particularly limited, and for example, a titanium-based coupling agent, a silane-based coupling agent, a melamine-based coupling agent, an epoxy-based coupling agent, an isocyanate-based coupling agent, and copper. Compound,<u style="single">zirconium</u>Compounds and the like can be mentioned, and more preferably<u style="single">zirconium</u>Compounds are mentioned.

【0022】<u style="single">zirconium</u>Specific examples of the compound include zirconium halides such as zirconium oxychloride, zirconium hydroxychloride, zirconium tetrachloride, and zirconium bromide, zirconium salts of mineral acids such as zirconium sulfate, basic zirconium sulfate, and zirconium nitrate, and zirconium formate. , Zirconium acetate, zirconium propionate, zirconium caprylate, zirconium salts of organic acids such as zirconium stearate, zirconium carbonate ammonium carbonate, sodium zirconium sulfate, zirconium ammonium acetate, sodium zirconium oxalate, sodium zirconium citrate, zirconium ammonium citrate, etc. Examples include zirconium complex salt.

[0023] The amount of the cross-linking agent added for the hydrogen-bonding group is the ratio (K) of the number of moles (CN) of the cross-linking forming groups of the cross-linking agent to the number of moles (HN) of the hydrogen-bonding groups of the high hydrogen-bonding resin. That is, as long as K = CN / HN] is in the range of 0.001 or more and 10 or less, the range is not particularly limited, but is preferably 0.01 or more and 1 or less.

[0024] The composition ratio (volume ratio) of the inorganic layered compound used in the present invention to the resin is not particularly limited, but in general, the volume ratio of (inorganic layered compound / resin) is 5/95 to 90 /. It is in the range of 10, and the volume ratio is more preferably in the range of 5/95 to 50/50. In addition, in the range of 5/95 to 30/70, the flexibility of the film is improved, and in the range of 7/93 to 17/83, the decrease in barrier property due to bending is small, and the peel strength is increased. Have. Further, when the volume fraction of the inorganic layered compound is smaller than 5/95, the barrier performance is not sufficient, and when it is larger than 90/10, the film forming property is not good.

[0025] The method for blending the composition composed of the inorganic layered compound and the resin is not particularly limited, but for example, the liquid in which the resin is dissolved and the inorganic layered compound are swollen in advance.<u style="single">and</u>After mixing with the cleaved dispersion, remove the solvent and swell the inorganic layered compound.<u style="single">and</u>Cleavage dispersion is added to the resin and the solvent is removed, and the inorganic layered compound is added to the solution in which the resin is dissolved to swell.<u style="single">and</u>Examples thereof include a method of removing the solvent after cleavage and a method of heat-kneading the resin and the inorganic layered compound. The former three are preferably used as a method for easily obtaining a particularly large aspect ratio.

[0026] In the above three methods, the solvent is removed from the system and then heat-aged at 110 ° C. or higher and 220 ° C. or lower to achieve water resistance of the film (meaning of barrier property after water resistance environment test). Is improved. Although the aging time is not limited, the film must reach at least a set temperature, and in the case of a method using a heat medium contact such as a hot air dryer, it is preferably 1 second or more and 100 minutes or less. The heat source is not particularly limited, and various heat sources such as heat roll contact, heat medium contact (air, oil, etc.), infrared heating, microwave heating, and the like can be applied. Further, the water resistance effect referred to here is remarkably high when the resin is a highly hydrogen-bonding resin and when the inorganic layered compound is a clay mineral having swelling property.

[0027] The metal or oxide thin film used in the present invention is not particularly limited as a metal, but is preferably one that is stable in air, and preferably aluminum or the like in which the film surface is oxidatively stabilized after thin film formation. .. As the oxide, aluminum oxide, silicon oxide, titanium oxide, zinc oxide and the like are preferable, and the oxidation state thereof may be various.

[0028] The film thickness of the thin film of metal or oxide used in the present invention is preferably 1 nm or more and 1000 nm or less. More preferably, it is 10 nm or more and 300 nm or less.

[0029] The method for forming a thin film of a metal or oxide used in the present invention is not particularly limited, and in addition to the general vacuum deposition method, a CVD method, a sputtering method, a sol-gel method, or the like is used. The metal is not particularly limited, but a metal that is stable in air is preferable, and aluminum or the like in which the film surface is oxidatively stabilized after thin film formation is preferably used. As the oxide, aluminum oxide, silicon oxide, titanium oxide, zinc oxide and the like are preferable, and the oxidation state thereof may be various.

[0030] The resin film on which the metal or oxide thin film used in the present invention is formed is not particularly limited, but biaxially stretched polyethylene terephthalate, biaxially stretched nylon, biaxially stretched polypropylene and the like are preferably used.

[0031] Further, the method of laminating a layer containing an inorganic layered compound on a thin film layer of a metal or an oxide is not particularly limited. A coating method in which the coating liquid of the composition is applied to the surface of the substrate, dried, and heat-treated on the thin film layer of the metal or oxide, or a method in which a layer containing the inorganic layered compound is later laminated is preferable. Further, the interface between the two may be treated with a corona treatment or an anchor coating agent. As coating methods, roll coating methods such as direct gravure method, reverse gravure method and micro gravure method, 2-roll beat coat method, bottom feed 3-reverse coat method, doctor knife method, die coat method, dip coat method, bar Examples include a coating method and a coating method that combines these methods.

[0032] The coating thickness of the layer containing the inorganic layered compound is not particularly limited, but the dry thickness is preferably 10 μm or less, more preferably 1 μm or less (the advantage is that the transparency of the laminate is remarkably high at 1 μm or less). It is even more preferable for applications that require transparency because it has a combination.) The lower limit is not particularly limited, but it is preferably 1 nm or more in order to obtain an effective gas barrier effect.

[0033] Further, the base material of the laminated film is not particularly limited, and general base materials such as resin, paper, aluminum foil, wood, cloth, and non-woven fabric can be mentioned. Resins used as the base material include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, ethylene- Vinyl acetate copolymer, ethylene-methylmethacrylate copolymer, polyolefin resin such as ionomer resin, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, nylon-6, nylon-6,6, metaxylene Diamine-adipic acid-condensed polymer, amide resin such as polymethylmethacrylimide, acrylic resin such as polymethylmethacrylate, polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, polyacrylonitrile, etc. Hydrophobic cellulose-based resins such as styrene, acrylonitrile-based resins, cellulose triacetate, cellulose diacetate, halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and Teflon, polyvinyl alcohol, ethylene-vinyl alcohol copolymers. , Hydrogen-binding resin such as cellulose derivative, polycarbonate resin, polysulfone resin, polyether sulfone resin, polyether ether ketone resin, polyphenylene oxide resin, polymer oxide resin, engineering plastic resin such as liquid crystal resin, and the like.

[0034] Among these, in the laminated body in the form of a film, as the outer layer, biaxially stretched polypropylene, polyethylene terephthalate, or biaxially stretched polypropylene coated with polyvinylidene chloride called nylon or K coat, Polyethylene terephthalate, nylon, etc. are preferably arranged, and the inner layer generally has good heat-sealing properties. Therefore, polyolefin resins such as polyethylene (low density, high density), ethylene-propylene copolymer, and ethylene-butene are used. copolymers, ethylene - hexene copolymer, an ethylene - octene copolymer, polypropylene, ethylene-vinyl acetate copolymer, ethylene - Mechirumeta acrylate copolymer, and ionomer resins are preferably used.

[0035] Further, in the present invention, various additives such as an ultraviolet absorber, a colorant, and an antioxidant may be mixed as long as the effect is not impaired. The present invention includes a laminated film and a laminated body having at least one laminated film layer described above.

[Effect of the Invention] According to the present invention, the particle size of the inorganic layered compound, which is a resin and an inorganic layered compound, is formed on a thin film layer of a metal or oxide formed on at least one surface of the resin film. By laminating layers using those having an aspect ratio of 50 or more and 5000 or less of 5 μm or less, it is possible to obtain a gas barrier laminated film having an unprecedented high level of gas barrier property.

That is, the film of the present invention can be used as a packaging material for foods such as miso, pickles, prepared foods, baby food, tsukudani, konjac, chikuwa, dried bonito, processed marine products, meat balls, hamburgers, Genghis Khan, and ham. Sausage, other processed meat products, green tea, coffee, tea, dried bonito, sardine kelp, potato chips, butter peanuts, etc. Oil confectionery, rice cakes, biscuits, cookies, cakes, buns, castella, cheese, butter, cut rice cakes, soups, sauces Widely used in ramen, etc., and in addition to pet food, pesticides / fertilizers, infusion packs, etc., industrial materials such as semiconductor packaging, oxidizing chemical packaging, precision material packaging, etc. It is used for a wide range of purposes such as packaging.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0039] The measuring methods of various physical properties are described below.

[Oxygen permeability] Measured with an oxygen permeability measuring device (OX-TRAN 10 / 50A, manufactured by MOCON) and a temperature of 31 ° C (humidity control constant temperature bath 21 ° C) (relative humidity showed about 61%). ..

[Thickness measurement] 0.5 μm or more was measured with a digital thickness meter. If it is less than 0.5 μm, the weight analysis method (the weight measurement value of a film having a certain area is divided by the area and further divided by the specific gravity of the composition), or in the case of a laminate of the composition and the base material of the present invention, etc. An element analysis method (a method of obtaining the ratio of the resin composition layer to the base material of the present invention from the ratio of the specific inorganic element analysis value (derived from the composition layer) of the laminate to the specific element fraction of the inorganic layered compound alone) was used. ..

[Measurement of particle size] Measurement was performed under the conditions of an ultrafine particle size analyzer (BI-90, manufactured by Brookhaven), a temperature of 25 ° C, and an aqueous solvent. The center diameter obtained by the photon correlation method by the dynamic light scattering method was defined as the particle size L.

[Aspect ratio calculation] Using an X-ray diffractometer (XD-5A, manufactured by Shimadzu Corporation), diffraction measurement was performed by the powder method of the inorganic layered compound alone and the resin composition. As a result, the surface spacing (unit thickness) a of the inorganic layered compound was determined, and further, it was confirmed from the diffraction measurement of the resin composition that there was a portion where the surface spacing of the inorganic layered compound was widened. Using the particle size L obtained by the above method, the aspect ratio Z was determined by the formula Z = L / a.

[Example 1] Natural montmorillonite (Kunipia F; manufactured by Kunimine Kogyo Co., Ltd.) was dispersed in ion-exchanged water (0.7 μS / cm or less) so as to be 2 wt%, and this was dispersed in an inorganic layered compound dispersion (inorganic layered compound dispersion). Liquid A). The particle size of the natural montmorillonite is 560 nm, the a value obtained from powder X-ray diffraction is 1.2156 nm, and the aspect ratio Z is 461. In addition, polyvinyl alcohol (PVA117H; manufactured by Kuraray Co., Ltd., degree of saponification; 99.6%, degree of polymerization 1700) was dissolved in ion-exchanged water (0.7 μS / cm or less) so as to be 2 wt%, and this was dissolved in a resin solution (B). Liquid). Liquid A and liquid B were mixed so that the solid component ratio (volume ratio) of each was inorganic layered compound / resin = 3/7, and this was used as a coating liquid. Gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed 3 m / min,) on the vapor-deposited surface of a 12 μm-thick silicon oxide vapor-deposited film (MOS; manufactured by Oike Kogyo). The drying temperature was 80 ° C (inlet side heater) and 100 ° C (outlet side heater)) to obtain a laminated film. The dry thickness of the coating layer is 0.3 It was μm. The oxygen permeability of this laminated film at 30 ° C and 60% RH was 0.1 cc / m 2 / day or less. (Table 1) [Examples 2 to 6] Table 1 shows the substrate, the inorganic layered compound, the resin, the ratio of the inorganic layered compound to the resin, the cross-linking agent for the hydrogen-bonding group, and the heat treatment conditions after film formation. With this configuration, a laminated film was prepared by the method of Example 1 and an oxygen permeability test was performed. As shown in Table 1, the results were excellent in gas barrier properties.

[Example 7] As a cross-linking agent for a hydrogen-bonding group, zirconium ammonium carbonate (first rare element industry zircozole AC7 (aqueous solution containing 15 wt% in terms of zirconium oxide)) is added to 1 mol of zirconium element with respect to 15 mol of hydroxyl groups of polyvinyl alcohol. It was added to the mixed solution of solution A and solution B so as to have the ratio of. The oxygen permeability test was carried out in the same manner as in Example 1 except that the other configurations are as shown in Table 1. The results were excellent in gas barrier properties as shown in Table 1.

[Example 8] As a cross-linking agent for a hydrogen-bonding group, zirconium ammonium carbonate (zircozole AC7 (an aqueous solution containing 15 wt% in terms of zirconium oxide) manufactured by Daiichi Rare Element Industry Co., Ltd.) is added to 15 mol of hydroxyl groups of polyvinyl alcohol. It was added to the mixed solution of solution A and solution B so as to have a molar ratio. Other than the configurations shown in Table 1, the film was formed in the same manner as in Example 1, and then the film was heat-treated at 140 ° C. for 10 minutes. As a result of the oxygen permeability test, the gas barrier property was excellent as shown in Table 1.

[Example 9] An unstretched polypropylene film (Toyobo: Pyrene film CT) is used as a urethane-based adhesive (Sanyo Kasei: Eunoflex J3) on the inorganic layered compound-containing layer of the laminated film obtained in Example 1. A thickness of 60 μm) was dry-laminated to obtain a laminated film. The oxygen permeability of this laminated film at 30 ° C and 60% RH was 0.1 cc / m 2 / day or less, and it was also excellent in heat sealability and transparency.

[Comparative Example 1] Without using the inorganic layered compound dispersion (solution A), it was dissolved in polyvinyl alcohol (PVA117H; manufactured by Kuraray Co., Ltd., degree of saponification; 99.6%, degree of polymerization 1700) to 2 wt%. A film was obtained in the same manner as in Example 1 except that this was used as a resin solution (solution B), and an oxygen permeability test was conducted. The results were inferior in gas barrier properties as shown in Table 1.

[Comparative Examples 2 to 4] The oxygen permeability test of the metal and oxide vapor deposition films shown in Table 1 was performed. The results were inferior in gas barrier properties as shown in Table 1.

[Comparative Example 5] A film was produced in the same manner as in Example 1 except that the resin solution (Liquid B) was not used, but the synthetic mica powder was peeled off from the laminated film, and scratches were conspicuous on the film surface, resulting in good lamination. No film was obtained.

[0041] [Table 1]<img file="JP3681426B2_D0001.tif" />Abbreviation MOS: Silicon oxide vapor-deposited polyethylene terephthalate film (Oike Kogyo: product name MOS) VMPET: Aluminum oxide-deposited polyethylene terephthalate film (Toyo Aluminum: product name VMPET) AL: Aluminum-deposited polyethylene terephthalate film (Oike Kogyo: product name Tetraite) F: Natural montmorillonite (Kunimine Industry: Product name Kunipia F) H: Polyvinyl alcohol (Kurare: Poval 117H, Degree of polymerization 1700, Degree of saponification 99.6 mol%) Z: Zyrosine ammonium carbonate aqueous solution (Manufactured by Daiichi Rare Element Industry: Zircosol AC7) A: Laminated film (after drying) is heat-treated at 140 ° C for 10 minutes [Brief description of drawings] [Fig. 1] Fig. 1 is a conceptual diagram of the layer structure of the cross section of the laminated film of the present invention.

FIG. 2 is a conceptual diagram of a layer structure of a cross section of the laminated film of the present invention.

FIG. 3 is a conceptual diagram of a layer structure of a cross section of the laminated film of the present invention.

FIG. 4 is a conceptual diagram of a layer structure of a cross section of the laminated film of the present invention.

FIG. 5 is a graph schematically showing the relationship between the X-ray diffraction peak of an inorganic layered compound and the unit thickness a of the compound.

FIG. 6 is a graph schematically showing the relationship between the X-ray diffraction peak of a resin composition containing an inorganic layered compound and the plane spacing d of the composition.

FIG. 7 shows the X-ray diffraction peak of the resin composition when the peak corresponding to the surface spacing d overlaps with the halo (or background) and is difficult to detect, and the surface spacing of the composition. It is a graph which shows the relationship with d schematically.

FIG. 8 is a graph showing an X-ray diffraction peak of polyvinyl alcohol PVA117H / Kunipia F composition and a graph showing an X-ray diffraction peak of Kunipia F (montmorillonite).

FIG. 9 is a graph showing the X-ray diffraction peaks (pattern of FIG. 6) of the composition with a plane spacing d = 19.62 angstroms.

FIG. 10 is a graph showing X-ray diffraction peaks (patterns of FIGS. 6 and 7) of a composition having a plane spacing of d = 32.94 angstroms.

FIG. 11 is a graph showing an X-ray diffraction peak (pattern of FIG. 7) of a composition having a surface spacing d of 44.13 angstroms or more.

[Code description] 1 Layer containing an inorganic layered compound 2 Metal or oxide thin film layer 3 Resin film 4 Laminating base material