JPH07251487A - Laminated film - Google Patents

Abstract

PURPOSE:To provide a laminated film having high-level gas barrier properties. CONSTITUTION:A laminated film consists of at least one layer of a resin composition which contains an inorganic layer-like chemical compound with a granular size of at most 5mum and an aspect ratio of at least 50 to at most 5000 and poly(vinyl alcohol), and also with the volume ratio of [inorganic layer-like chemical compound/poly(vinyl alcohol)] being within a range of (5/95)-(30/70), on a base layer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated film having excellent gas barrier properties.

[0002]

BACKGROUND OF THE INVENTION Although various functions are required for packaging, various gas barrier properties for protecting contents are important properties that affect the storability of foods. Distribution forms, diversification of packaging technology, regulation of additives However, due to changes in tastes and the like, the need for it is increasing. The gas barrier property was also a weak point of general plastic materials. Degradation factors of food include oxygen, light, heat, water, etc., and oxygen is particularly important as a substance causing it. The barrier material is a material that is indispensable for effectively blocking oxygen and at the same time controlling the deterioration of foods such as gas filling and vacuum packaging.In addition to oxygen gas, various gases, organic solvent vapors, fragrances, 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 confectionery bags, skipjack packs, retort pouches, carbon dioxide beverage containers, and other food products, cosmetics, agricultural chemicals, medical care, and the like.

Among the films made of thermoplastic resin, particularly oriented films of polypropylene, polyester, polyamide and the like have excellent mechanical properties, heat resistance and transparency and are widely used as packaging materials. There is. However, when these films are used for food packaging, they have insufficient oxygen and other gas barrier properties,
Various problems such as oxidative deterioration and alteration of contents due to aerobic microbes, permeation of aroma components, loss of flavor, and moistening of contents by external moisture, resulting in poor mouthfeel. Tend to occur. Therefore, a method such as stacking another film layer having a good gas barrier property is usually adopted.

Conventionally, various transparent plastic materials having a small gas barrier property are also known. For example, although there are films made of polyvinyl alcohol, polyethylene vinyl alcohol copolymer and polyvinylidene chloride resin, they can be bottled or bottled. While the metal and glass materials used have almost zero oxygen permeability, these plastic materials are still permeable to oxygen that cannot be ignored.

In addition to the above, as a method of exhibiting gas barrier properties, there is a method of dispersing a flat inorganic material in a resin. In JP-A-3-30944, polyvinyl alcohol and synthetic hectorite have a weight ratio of 20:80. The coating composition, which is the ratio, is applied onto biaxially oriented polyethylene terephthalate (OPET) and dried to form a coated film. However, the film obtained by this technique is still insufficient in gas barrier property, and cannot be said to be necessarily satisfactory.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a film having a high level of gas barrier property.

[0007]

Means for Solving the Problems As a result of extensive studies to solve the above problems, a base layer contains 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 polyvinyl alcohol, The volume ratio of the inorganic layered compound / polyvinyl alcohol) is (5/95) to (30 /
It was found that a laminated film having at least one layer composed of the resin composition in the range of 70) exhibits remarkably excellent gas barrier properties, and has reached the present invention.

That is, according to the present invention, the base layer has a particle size of 5 μm.
Including an inorganic layered compound having an aspect ratio of 50 or more and 5000 or less and polyvinyl alcohol, the volume ratio of (inorganic layered compound / polyvinyl alcohol) is (5/95).
The invention relates to a laminated film having at least one layer composed of a resin composition in the range of (30/70).

The inorganic layered compound used in the present invention is
An inorganic compound in which unit crystal layers are stacked on each other to have a layered structure. In other words, "layered compound" means
A compound or substance having a layered structure, and a "layered structure" is a structure in which atoms are strongly bonded by covalent bonds or the like and the densely arranged faces are stacked in parallel by weak bonding forces such as van der Waals forces. Say. The “inorganic layered compound” that can be used in the present invention has an aspect ratio of 50 or more and 5000 or less and a particle size of 5 μm as measured by the method described below.
The following are not particularly limited. From the viewpoint of gas barrier properties, the aspect ratio is preferably 100 or more (particularly 200 or more). When the aspect ratio is less than 50, the gas barrier property is insufficiently expressed. On the other hand, it is technically difficult to obtain an inorganic layered compound having an aspect ratio of more than 5,000, and it is expensive in terms of cost or economy. From the viewpoint of ease of manufacturing, the aspect ratio is preferably 2000 or less (further 1500 or less). From the viewpoint of the balance between gas barrier properties and easiness of production, the aspect ratio is more preferably in the range of 200 to 3000. From the viewpoint of film formability or moldability when formed into a film, the “particle size” measured by the method described below is preferably 5 μm or less. If the particle size exceeds 5 μm, the film-forming property or moldability of the resin composition tends to deteriorate. From the viewpoint of transparency of the resin composition, the particle size is preferably 3 μm or less. When the film of the present invention is used for applications where transparency is important (for example, food applications), it is particularly preferable that the particle size is 1 μm or less. Also, this transparency is
The total light transmittance at a wavelength of 500 nm is preferably about 80% or more (more preferably 85% or more). Such transparency can be suitably measured with, for example, a commercially available spectrophotometer (manufactured by Hitachi, Ltd., self-recording spectrophotometer Model 330). Specific examples of the inorganic layered compound include graphite, phosphate-based derivative-type compounds (zirconium phosphate-based compounds), chalcogenides [Group IV (Ti, Zr,
Hf), group V (V, Nb, Ta) and group VI (Mo,
W) is a dichalcogenide and is represented by the formula MX ₂ . Here, X represents chalcogen (S, Se, Te). ], Clay-based minerals and the like can be mentioned.

Since it is extremely difficult to measure the true particle size in a resin composition, the particle size of the inorganic layered compound used in the present invention is a value determined by a dynamic light scattering method in a solvent.
When sufficiently swelling with a solvent of the same kind as the solvent used in the dynamic light scattering method to form a composite 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.

The aspect ratio (Z) of the inorganic layered compound used in the present invention is represented by the relationship Z = L / a.
[L is a particle size obtained by a dynamic light scattering method in a solvent, and a is a unit thickness of the inorganic layered compound (unit thickness a is a measurement of the inorganic layered compound alone by a powder X-ray diffraction method or the like. It is a value determined by.)]. However, Z = L / a
, The interplanar spacing d obtained from powder X-ray diffraction of the composition
Exists and satisfies the relationship of a <d. Here, it is necessary that the value of da is larger than the width of the resin single chain in the composition. Z cannot necessarily be said to be the true aspect ratio of the inorganic layered compound in the resin composition, but for the following reasons,
It is quite valid.

Direct measurement of the aspect ratio of the inorganic layered compound in the resin composition is extremely difficult. Composition powder X
Between the interplanar spacing d obtained by the line diffraction method and the unit thickness a determined by the powder X-ray diffraction measurement of the inorganic layered compound alone, a <d
If the value of da is equal to or more than the width of the resin single chain in the composition, it means that the resin is inserted between the layers of the inorganic layered compound in the resin composition. It is clear that the thickness of the layered compound is the unit thickness a. In addition, it is extremely difficult to measure the true particle size in the resin composition, but in the case of swelling sufficiently with a solvent of the same kind as the solvent used in the dynamic light scattering method to form a composite with the resin, It can be considered that the particle size of the inorganic layered compound in is very close to that in the solvent (however, the particle size L determined by the dynamic light scattering method is the major axis Lma of the inorganic layered compound).
Since it is considered that x does not exceed x, the true aspect ratio Lmax / a cannot theoretically fall below the definition Z of the aspect ratio in the present invention. ). From the above two points, the definition of the aspect ratio of the present invention is considered to be relatively valid. In the present invention, the aspect ratio or particle size means the aspect ratio and particle size defined above. For details of how to obtain a and d, refer to, for example, Shu Iwao et al., Encyclopedia of Clay, pages 35 and below and pages 271 and below, 1985, Asakura Shoten Co., Ltd. 5-11).
The width of the resin single chain in the composition can be determined by simulation calculation or the like (for example, Okamura et al., Introduction to Polymer Chemistry, pages 103 to 110, 1981).
Years, Kagaku Dojin), 4-5 angstroms for polyvinyl alcohol (2-3 angstroms for water molecules). Thus, the diffraction peak (corresponding to the surface spacing d) observed in the powder X-ray diffraction of the resin composition
The integrated intensity of is a relative ratio of the reference diffraction peak (corresponding to the surface spacing a) to the integrated intensity of 2 or more (further 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 interplanar spacing d of the composition when the peak corresponding to the interplanar spacing d overlaps with the halo (or background) and is difficult to detect. It is a graph which shows typically. In this figure, 2
The area excluding the base line on the lower angle side than θd is defined as the peak corresponding to the surface spacing d (θd is the diffraction angle corresponding to “unit thickness a + width of single resin chain”). FIG. 8 shows polyvinyl alcohol PVA117H /
3 is a graph showing an X-ray diffraction peak of a Kunipia F composition and a graph showing an X-ray diffraction peak of Kunipia F (montmorillonite). FIG. 9 is a graph showing an X-ray diffraction peak (pattern of FIG. 6) of the composition having the interplanar spacing d = 19.62 angstrom. In FIG. 10, the surface spacing d = 32.
X-ray diffraction peak of the 94 Å composition (Fig. 6).
And the pattern of FIG. 7). FIG. 11 shows
8 is a graph showing X-ray diffraction peaks (pattern of FIG. 7) of a composition having a surface spacing d of 44.13 Å or more.

As the inorganic layered compound having a large aspect ratio, an inorganic layered compound which swells and cleaves in a solvent is preferably used. The degree of "swelling / cleavage" of the inorganic layered compound used in the present invention in a solvent is as follows.
It can be evaluated by the "cleavage" test. The swelling property of the inorganic layered compound is preferably about 5 or more (more preferably about 20 or more) in the following swelling test.
On the other hand, the cleavage property of the inorganic layered compound is preferably about 5 or more (more preferably about 20 or more) in the following cleavage property test. In these cases, a solvent having a density lower than that of the inorganic layered compound is used as the solvent. When the inorganic layered compound is a natural swelling clay mineral, it is preferable to use water as the solvent. <Swelling test>: Inorganic layered compound 2 g, solvent 100 mL
Slowly add to the container (contain a 100 mL graduated cylinder). After shaking and standing, the volume of the former (inorganic layered compound dispersed layer) is read from the scale of the interface between the inorganic layered compound dispersed layer and the supernatant after 24 hours at 23 ° C. The larger this value, the higher the swelling property. <Cleavability test>: 30 g of the inorganic layered compound is used as the solvent 150
Add slowly to 0 mL, disperser (manufactured by Asada Tekko KK, Despar MH-L, blade diameter 52 mm, rotation speed 3100 rp)
m, container volume 3 L, bottom-blade distance 28 mm), and dispersed at a peripheral speed of 8.5 m / sec for 90 minutes (23
℃), take 100 mL of the dispersion liquid, 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 of the interface with the supernatant. The larger this value, the higher the cleavability. As the inorganic layered compound that swells and cleaves in a solvent, a clay mineral that has a swelling and cleaving property in a solvent can be preferably used. Clay-based minerals are generally
A type having a two-layer structure having an octahedron layer having a central metal such as aluminum or magnesium on a tetrahedral layer of silica, and a tetrahedral layer of silica having an octahedron layer having a central metal such as aluminum or magnesium. It is classified as a type consisting of a three-layer structure in which is sandwiched from both sides. Examples of the former include kaolinites and antigorites, and examples of the latter include smectites, vermiculites and mica depending on the number of interlayer cations. Specifically, kaolinite, dickite,
Nacrite, halloysite, antigorite, chrysotile, pyrophyllite, montmorillonite, hectorite, tetrasilylic mica, sodium teniolite, muscovite, margarite, talc, vermiculite, phlogopite, xanthophyllite, chlorite, etc. be able to.

The solvent for swelling the present inorganic layered compound is not particularly limited. For example, in the case of a natural swelling clay mineral, water, alcohols such as methanol, dimethylformamide, dimethylsulfoxide, acetone and the like can be mentioned. Alcohols such as methanol are more preferred.

The polyvinyl alcohol used in the layer containing the inorganic layered compound of the present invention is a polymer having a monomer unit of vinyl alcohol as a main component. Examples of such "polyvinyl alcohol" include, for example, a polymer obtained by hydrolyzing or transesterifying (saponifying) the acetic ester portion of a vinyl acetate polymer (precisely, it is a copolymer of vinyl alcohol and vinyl acetate). thing)
And 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. (for details of "polyvinyl alcohol") Can be referred to, for example, "World of PVA", edited by Poval Society, 1992, Polymer Publishing Co., Ltd .; Nagano et al., Poval, 1981, Polymer Publishing Co., Ltd.). The degree of "saponification" in polyvinyl alcohol is preferably 70% or more, more preferably 85% or more, and more preferably 98% or more so-called completely saponified product in terms of molar percentage. The degree of polymerization is preferably 100 or more and 5000 or less (further,
200 or more and 3000 or less are preferable).

The hydrogen-bonding group crosslinking agent used in the present invention is not particularly limited, but examples thereof include titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, and isocyanate coupling agents. A coupling agent, a copper compound, a zirconia compound, etc. are mentioned, More preferably, a zirconia compound is mentioned.

Specific examples of zirconia compounds include zirconium oxychloride, zirconium hydroxychloride, zirconium tetrachloride, zirconium halides such as zirconium bromide, zirconium sulfate, basic zirconium sulfate, zirconium nitrate and other mineral acids. Zirconium salts of organic acids such as salts, zirconium formate, zirconium acetate, zirconium propionate, zirconium caprylate, zirconium stearate, ammonium zirconium carbonate, sodium zirconium sulfate, ammonium zirconium acetate, sodium zirconium oxalate, sodium zirconium citrate, citric acid Zirconium complex salts such as zirconium ammonium,
And so on.

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

The composition ratio (volume ratio) of the inorganic layered compound and the resin used in the present invention is (inorganic layered compound / resin) in the range of 5/95 to 30/70,
The film has good flexibility, and deterioration of the barrier property due to peeling from the base material or bending is suppressed. Furthermore, 7 / 93-17 / 83
Within the range, there is an advantage that the barrier property is hardly reduced by bending and a high barrier property is obtained.

The method of blending the composition comprising the inorganic layered compound and polyvinyl alcohol is not particularly limited, but, for example, after mixing the liquid in which polyvinyl alcohol is dissolved and the dispersion in which the inorganic layered compound is swollen and cleaved in advance, , The method of removing the solvent, the dispersion of swollen and cleaved the inorganic layered compound is added to the polyvinyl alcohol, the method of removing the solvent, the inorganic layered compound is added to the solution in which the polyvinyl alcohol is dissolved, the swollen and cleaved dispersion And a method of removing the solvent, a method of thermally kneading the polyvinyl alcohol and the inorganic layered compound, and the like. The former three methods are preferably used as a method for easily obtaining a particularly large aspect ratio.

In the former three methods, the solvent is removed from the system and then heat-aged at 110 ° C. or higher and 220 ° C. or lower to improve the water resistance of the film (meaning the barrier property after the water resistance environment test). To do. Although the aging time is not limited, it is necessary that the film reaches at least the set temperature, and in the case of a method using a heating medium contact such as a hot air dryer, it is preferably 1 second or more and 100 minutes or less. The heat source is also not particularly limited, and includes heat roll contact, heat medium contact (air, oil, etc.), infrared heating, microwave heating,
Various other types can be applied.

The base material used in the base material layer of the present invention is not particularly limited, and examples thereof include general base materials such as resin, paper, aluminum foil, wood, cloth and non-woven fabric. As the resin used as the base material, polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, ethylene- Polyvinyl terephthalate, polybutylene terephthalate, polyethylene naphthalate, and other polyester resins, including vinyl acetate copolymers, ethylene-methyl methacrylate copolymers, ionomer resins, and other polyolefin resins, nylon-6, nylon-6,6 , Methaxylenediamine-adipic acid condensation polymer, amide resin such as polymethylmethacrylimide, acrylic resin such as polymethylmethacrylate, polystyrene, styrene-acrylonitrile copolymer, styrene-acryloni Ryl-butadiene copolymer, styrene such as polyacrylonitrile, acrylonitrile resin, cellulose triacetate, hydrophobized cellulose resin such as cellulose diacetate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, halogen-containing resin such as Teflon , Polyvinyl alcohol, ethylene-vinyl alcohol copolymer, hydrogen bonding resin such as cellulose derivative, polycarbonate resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyphenylene oxide resin, polymethylene oxide resin, liquid crystal resin Such as engineering plastic resin.

As the resin layer used in the base material layer of the present invention, a film which has been stretched, particularly biaxially stretched, in terms of strength and gloss is used. For example, a biaxially oriented polypropylene film, a biaxially oriented polyamide film, a biaxially oriented polyethylene terephthalate film and the like can be mentioned.

The method for laminating the laminated film of the present invention is not particularly limited. In order to stack a layer containing an inorganic layered compound on a base material layer, a coating method of applying a coating liquid of a composition containing an inorganic layered compound and a resin on the surface of a base material, drying and heat treatment, a layer containing an inorganic layered compound. Is preferably laminated on a substrate later, or a method of extruding and laminating a resin on a layer containing an inorganic layered compound is preferable. Further, the interface between the both may be treated with corona treatment or anchor coating agent. As a coating method, a direct gravure method, a reverse gravure method, a micro gravure method, a roll coating method such as a two roll beat coating method, a bottom feed three reverse coating method, a doctor knife method, a die coating method, a dip coating method, and a bar coating method. Examples thereof include a coating method and a coating method combining these methods.

The thickness of the layer containing the inorganic layered compound is not particularly limited, but is preferably 10 μm or less in dry thickness, more preferably 1 μm or less (the advantage that the transparency of the laminate is remarkably high when it is 1 μm or less is also taken into consideration. Therefore, it is more preferable for applications requiring transparency). The lower limit is not particularly limited, but is preferably 1 nm or more in order to obtain an effective gas barrier effect.

The laminated film of the present invention may be laminated with other base materials depending on the purpose. The base material is not particularly limited, and examples thereof include general base materials such as the resin, paper, aluminum foil, wood, cloth, and non-woven fabric described above.

Further, in the present invention, various additives such as an ultraviolet absorber, a colorant, an antioxidant and the like may be mixed within a range that does not impair the effect.

[0028]

According to the present invention, the particle size is 5 on the substrate layer.
Including an inorganic layered compound having an aspect ratio of 50 or more and 5000 or less and polyvinyl alcohol, the volume ratio of (inorganic layered compound / polyvinyl alcohol) is (5/9).
By using a laminated film having at least one layer composed of the resin composition in the range of 5) to (30/70), it becomes possible to obtain a high level of gas barrier property which has never been obtained. As shown in Examples, the inorganic layered compound having a small aspect ratio has a small gas barrier property-imparting effect, and the smaller the volume fraction of the inorganic layered compound, the more difficult it is to form pinholes against bending. That is, it can be seen that the film is removed and the peel strength when another substrate is laminated on the layer containing the inorganic stratiform compound is greatly improved.

The film of the present invention is used as a packaging material for foods, such as miso, pickles, side dishes, baby food, Tsukudani, konjac, chikuwa, kamaboko, seafood products, meatballs, hamburgers, Genghis Khan, ham, sausages,
Other processed meat products, green tea, coffee, black tea, bonito flakes, grated kelp, potato chips, butter peanuts and other oil confectionery, rice crackers, biscuits, cookies, cakes, buns, castella, cheese, butter, mochi, soup, sauce, ramen Widely used for, such as pet food, agricultural chemicals / fertilizers, infusion packs, etc., as well as semiconductor packaging, oxidizing chemical packaging, precision material packaging, etc. Medical, electronic, chemical, mechanical industrial material packaging, etc. In addition, it is used for a wide range of purposes.

[0030]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

The methods for measuring various physical properties are described below. [Oxygen permeability] Oxygen permeability measuring device (OX-TRAN 1
0 / 50A, made by MOCON), temperature 30 ° C (humidity control thermostat 2
It was measured at 0 ° C. (relative humidity showed about 60%). [Bending test] A non-stretched polypropylene film (Toyobo: Pyrene film CT thickness 50 μm) was dry-laminated on the side of the layered film containing the inorganic layered compound using a urethane adhesive (Sanyo Kasei: Eunoflex J3). The film thus obtained was sampled, bent in a lattice pattern at 1 cm intervals, and the oxygen permeability measurement was performed on the film. If bending causes bending to form pinholes in the layered inorganic compound-containing layer, the oxygen permeability will increase. [Film Strength Test] Cellophane tape was attached to the side of the layered film containing the inorganic layered compound, and a 90 ° peel test was conducted. The one in which the layer containing the inorganic layered compound was destroyed was represented by x, and the one without was represented by o. [Thickness measurement] A thickness of 0.5 μm or more was measured by a digital thickness meter. When the thickness is less than 0.5 μm, a 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 of the present invention and a substrate, , Elemental analysis method (a method for obtaining the ratio of the resin composition layer of the present invention to the base material from the ratio of the specific inorganic element analysis value (derived from the composition layer) of the laminate and the specific element fraction of the inorganic layered compound alone) It was [Measurement of Particle Size] Ultrafine particle size analyzer (BI-90, manufactured by Brookhaven Co., Ltd.) was used under the conditions of a temperature of 25 ° C. and a water solvent. The central diameter determined by the photon correlation method by the dynamic light scattering method was defined as the particle diameter L. [Aspect ratio calculation] X-ray diffractometer (XD-5A,
Diffraction measurement was performed on the inorganic layered compound alone and the resin composition by a powder method using Shimadzu Corporation. Thus, the interplanar spacing (unit thickness) a of the inorganic layered compound was determined, and it was further confirmed from the diffraction measurement of the resin composition that the interplanar spacing of the inorganic layered compound was wide. Using the particle size L obtained by the above method, the aspect ratio Z is Z = L /
It was determined by the formula a.

[Example 1] Natural montmorillonite (Kunimine Industries Co., Ltd .: Kunipia F) was deionized water (0.7).
μS / cm or less) so as to be 1 wt%, and this is used as an inorganic layered compound dispersion liquid (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 (PVA1
17H; manufactured by Kuraray Co., Ltd., saponification degree: 99.6%, polymerization degree: 170
0) is dissolved in ion-exchanged water (0.7 μS / cm or less) to 1 wt%, and this is used as a resin solution (solution B). A
The liquid and the liquid B were mixed so that the ratio of solid components (volume ratio) was inorganic layered compound / resin = 5.3 / 94.7, and this was used as a coating liquid. After a corona treatment of a 20 μm thick biaxially oriented polypropylene film (Toyobo: Pyrene film OT), the composition liquid was gravure coated (test coater; Yasui Seiki Co., Ltd .: micro gravure coating method, coating speed 3 m). / Min, the drying temperature was 80 ° C (heater on the inlet side) and 100 ° C (heater on the outlet side). The dry thickness of the coating layer was 0.8 μm. The oxygen permeability, bending test, and film strength test were performed on the obtained laminated film. The results were excellent as shown in Table 2. (Table 2) [Examples 2 to 7] An inorganic layered compound and a ratio of the inorganic layered compound and polyvinyl alcohol are shown in Table 1, respectively. A transmittance, a bending test, and a film strength test were performed respectively. The results were excellent as shown in Table 2.
(Table 2) [Example 8] Ammonium zirconium carbonate (Zircosol AC7 manufactured by Daiichi Rare Elements Industry (15 wt% zirconium oxide-containing aqueous solution)) was added to 15 mol of hydroxyl groups of polyvinyl alcohol as a cross-linking agent for hydrogen-bonding groups. On the other hand, the zirconium element was added to the mixed solution of the liquid A and liquid B in a ratio of 1 mol. Other than the above, except that the base material was a biaxially-stretched polyethylene terephthalate film (manufactured by Toray: Lumirror), the constitution was as shown in Table 1 and in the same manner as in Example 1,
The oxygen permeability and the film strength test were conducted respectively. The results were excellent as shown in Table 2. (Table 2) [Example 9] As a hydrogen-bonding group-crosslinking agent, zirconium ammonium carbonate (Zircozol AC7 manufactured by Daiichi Rare Elements Industry Co., Ltd. (15 wt% zirconium oxide-containing aqueous solution)) was used as a hydroxyl group of polyvinyl alcohol (15 mol). With respect to the zirconium element, 1 mol of zirconium was added to the mixed solution of solution A and solution B. After forming a film in the same manner as in Example 7 except that the constitution was as shown in Table 1, the film was heat-treated at 180 ° C. for 5 minutes to obtain a laminated film. The results of the oxygen permeability and the film strength test, respectively, were excellent as shown in Table 2. (Table 2) [Comparative Examples 1 and 2] A film having the constitution shown in Table 1 was obtained in the same manner as in Example 1 except that an inorganic layered compound having a small aspect ratio was used. Oxygen permeability, bending test, film Each strength test was performed. The results are as shown in Table 2,
The gas barrier property was greatly inferior. (Table 2) [Comparative Example 3] A laminated film was prepared by the method of Example 1 with the composition shown in Table 1 for the ratio of the inorganic layered compound and polyvinyl alcohol, and the oxygen permeability, bending test, and film were prepared. Each strength test was performed. As the results are shown in Table 2, the bendability was remarkably inferior and the film strength was weak. (Table 2) [Comparative Example 4] A laminated film was prepared by the method of Example 1 with the composition shown in Table 1 for the ratio of the inorganic layered compound and polyvinyl alcohol, and the oxygen permeability, bending test, and film were prepared. Each strength test was performed. As the results are shown in Table 2, the bendability was remarkably inferior and the film strength was weak. (Table 2) [Comparative Example 5] A ratio of an inorganic layered compound to polyvinyl alcohol and a cross-linking agent for a hydrogen-bonding group are shown in Table 1,
A laminated film was prepared by the method of Example 9, and the oxygen permeability and the film strength test were respectively performed. As the result is shown in Table 2, the film strength was weak. (Table 2) [Comparative Example 6] A 20 μm thick biaxially stretched polypropylene film (Toyobo: Pyrene film OT) has an oxygen permeability of 1000 cc / m ² · day · atm or more, which is extremely inferior in gas barrier property. there were.

[0033]

[Table 1]

[Table 2] Abbreviation CPP: Polypropylene film (Toyobo: product name Pyrene film CT) OPP: Biaxially oriented polypropylene film (Toyobo:
Product name Pyrene film OT) OPET: Biaxially oriented polyethylene terephthalate film (Toray: product name Lumirror) NA: Tetrasilicic mica micronized product (Topy Industries:
Product name NaTs) Particle size / a value / Z = 977 nm / 0.95
57 nm / 1043 F: Natural montmorillonite (Kunimine Industries: product name Kunipia F) Particle size / a value / Z = 560 nm / 1.2156 nm
/ 461 L: Synthetic hectorite (Nippon Silica Industry: product name Laponite XLS) Particle size / a value / Z = 35 nm / about 1 nm (diffraction peak broad) / about 35 H: Polyvinyl alcohol (Kuraray: Poval 117
H, degree of polymerization 1700, degree of saponification 99.6 mol%) 117: polyvinyl alcohol (manufactured by Kuraray: Poval 1
17, degree of polymerization 1700, degree of saponification 98.5 mol%) Z: ammonium zirconium carbonate aqueous solution (manufactured by Daiichi Rare Element Industry: Zircosol AC7) A: 180 ° C., heat treatment for 5 minutes

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a film structure of a cross section of a laminated film of the present invention.

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

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

FIG. 4 is a conceptual diagram of a film 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 interplanar spacing d of the composition.

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

FIG. 8 shows polyvinyl alcohol PVA117.
It is a graph which shows the X-ray diffraction peak of H / Kunipia F composition, and the graph which shows the X-ray diffraction peak of Kunipia F (montmorillonite).

FIG. 9 is a graph showing an X-ray diffraction peak (pattern of FIG. 6) of a composition having an interplanar spacing d = 19.62 angstroms.

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

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

[Explanation of symbols]

 1 Layer containing an inorganic layered compound 2 Base material layer 3 Other base material layers

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C09C 1/42 PBC (72) Inventor Toshiya Kuroda 2-10-1 Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Gaku Kogyo Co., Ltd.

Claims (10)

[Claims] 1. The substrate layer contains 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 polyvinyl alcohol, and the volume ratio of (inorganic layered compound / polyvinyl alcohol) is (5/95). A laminated film having at least one layer of the resin composition in the range of (30/70). 2. The laminated film according to claim 1, wherein the inorganic layered compound swells and cleaves in a solvent. 3. The laminated film according to claim 2, wherein the inorganic layered compound is a swelling clay mineral. 4. The aspect ratio of the inorganic layered compound is 200.
It is-3000, The laminated film of Claim 1, 2 or 3 characterized by the above-mentioned. 5. The volume ratio of (inorganic layered compound / resin) is (7
/ 93) to (17/83). The laminated film according to any one of claims 1 to 4, wherein 6. The laminated film according to any one of claims 1 to 5, wherein the inorganic layered compound layer contains a crosslinking agent for hydrogen-bonding groups. 7. The laminated film according to claim 6, wherein the crosslinking agent for hydrogen-bonding group is a zirconia compound. 8. The method according to claim 1, wherein the inorganic layered compound is obtained by dispersing it in a resin or a resin solution in a state of being swollen and cleaved in a solvent, and removing the solvent from the system while maintaining the state. 2. The method for producing a laminated film according to item 1. 9. A laminated film or a laminate having at least one layer of the laminated film according to any one of claims 1 to 7. 10. The oxygen permeability at 30 ° C. and 60% RH is 0.2 cc / m ² · day · atm or less, according to claim 9 or any one of claims 1 to 7. The laminated film or laminated body according to.