JPH07251489A - Humidity-proof laminated film - Google Patents

Abstract

PURPOSE:To obtain a laminated film applied to food wrapping for its high humidity proofness and gas barrier properties by laminating a layer consisting of a resin composition containing an inorganic layer-like chemical compound with a specific granular size and a specific aspect ratio and a resin between two polyolefin resin layers. CONSTITUTION:A humidity-proof laminated film consists of at least one layer 1 of a resin composition containing an inorganic layer-like chemical compound with a granular size of at most 5mum and an aspect ratio raging from 50 to 5000 and a resin, laminated between two polyolefin resin layers 2, 3. In this case, the inorganic layer-like chemical compound should be one which swells and cleaves in a solvent and a viscous mineral having swelling properties. In addition, the chemical compound should have the aspect ratio specified as ranging from 200 to 3000. Further, the volume ratio between the inorganic layer-like chemical compound and the resin should be specified as ranging from 5/95 to 90/10. The resin should be a high hydrogen bonding resin such as having the weight percentage of a hydrogen bond group or an inonic group per unit resin weight specified as ranging from 30 to 50%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film excellent in moisture resistance and other 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 large gas barrier property are also known. For example, although there are films made of polyvinyl alcohol, polyethylene vinyl alcohol copolymer and polyvinylidene chloride resin, etc., metal used for canning and bottling. While glass and glass materials have almost zero oxygen permeability, these plastic materials are still permeable to oxygen that cannot be ignored.

In addition, as a method of exhibiting gas barrier properties, there is a method of dispersing a flat inorganic material in a resin. For example, JP-A-62-148532 discloses 1,6-
100 parts by weight of a 30% polyurethane resin solution containing hexanepolycarbonate diol, 25 parts by weight of fine powder of mica and 60 parts by weight of dimethylformamide were coated on a releasable substrate and dried. Then, a manufacturing method of peeling from the substrate is described. In addition, JP-A-64-
No. 043554 discloses that an aqueous solution of ethylene / vinyl alcohol copolymer in methanol is added with mica having an average length of 7 μm and an aspect ratio of 140, which is poured into cold water to cause precipitation, filtration, drying and pelletization. And then a method for obtaining a film is described. Further, JP-A-3-
No. 93542 discloses a modified silyl group-containing polyvinyl alcohol and synthetic hectorite in a weight ratio of 50:50.
Is applied onto biaxially oriented polyethylene terephthalate (OPET), dried and heat treated (13
0 to 150 ° C.) is described. However, the films obtained by these techniques are not yet satisfactory in gas barrier properties, and it cannot be said that they are necessarily satisfactory.

[0005]

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

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a particle size of 5 μm or less and an aspect ratio of 50 or more and 5000 or less between the polyolefin resin layers A and B. It was found that a laminated film having at least one layer composed of a resin composition characterized by containing an inorganic layered compound and a resin described in (1) exhibits remarkably excellent moisture resistance and gas barrier property. .

That is, according to the present invention, the particle size is 5 μm or less and the aspect ratio is 5 between the polyolefin resin layers A and B.
The present invention relates to a moisture-proof laminated film having at least one layer made of a resin composition containing 0 to 5,000 inorganic layered compound and a resin.

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 represented by the formula MX2. Here, X represents chalcogen (S, Se, Te). ], Clay-based minerals and the like can be mentioned. 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,
There is no particular limitation as long as the particle size is 5 μm or less and the aspect ratio is 50 or more and 5000 or less. Regarding the gas barrier property, the aspect ratio is more preferably in the range of 200 to 3000. If the aspect ratio is less than 50, the gas barrier property is not sufficiently exhibited, and if it is more than 5000, it is technically difficult and economically expensive. Also,
When the particle size is 3 μm or less, the transparency is better, and when the particle size is 1 μm or less, the transparency is more preferable for applications where importance is attached to the transparency. Specific examples of the inorganic layered compound include:
Graphite, phosphate derivative compounds (zirconium phosphate compounds), chalcogenides [Group IV (Ti,
Zr, Hf), group V (V, Nb, Ta) and group VI (Mo, W) dichalcogenides, represented by the formula MX ₂ . Where X is chalcogen (S, Se, Te)
Indicates. ], 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 resin used in the present invention is not particularly limited, but for example, polyvinyl alcohol (PV
A), ethylene-vinyl alcohol copolymer (EVO
H), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), polysaccharides, polyacrylic acid and its esters, and the like.

As a preferred example, the weight percentage of hydrogen bonding groups or ionic groups per unit weight of resin is 20% to 20%.
A high hydrogen-bonding resin satisfying the ratio of 60% can be mentioned. A more preferable example is one in which the weight percentage of hydrogen-bonding groups or ionic groups per unit weight of the resin 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 sulfonate ion group, and a phosphoric acid group. Ionic groups, ammonium groups, phosphonium groups and the like can be mentioned. Among the hydrogen-bonding groups or ionic groups of the high hydrogen-bonding resin, more preferable examples include a hydroxyl group, amino group, carboxyl group, sulfonic acid group, carboxylate group, sulfonate ion group, ammonium group, and the like. To be

Specific examples include polyvinyl alcohol, ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 41 mol% or more, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, amylose, amylopectin, pullulan, curdlan, xanthan. Polysaccharides such as chitin, chitosan, cellulose, pullulan, chitosan, etc., polyacrylic acid, sodium polyacrylate, polybenzenesulfonic acid, sodium polybenzenesulfonate, polyethyleneimine, polyallylamine, its ammonium salt polyvinylthiol, poly Glycerin, etc. are mentioned.

Further preferable examples of the high hydrogen bond resin include polyvinyl alcohol and polysaccharides.
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). 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 (“polyvinyl alcohol”).
For more details, refer to, for example, "The 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 in terms of molar percentage, and 85
% Or more, more preferably 98% or more, a so-called completely saponified product. The degree of polymerization is 100.
Or more and 5000 or less (more preferably 200 or more and 3
000 or less is preferable).

The term "polysaccharide" as used herein refers to a biopolymer synthesized in a biological system by polycondensation of various monosaccharides, and herein includes those chemically modified based on them. For example, cellulose and cellulose derivatives such as hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, amylose, amylopectin, pullulan, curdlan, xanthan, chitin,
Examples include chitosan.

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 barrier property after a water resistance environment test). it can.

The crosslinking agent for hydrogen-bonding group is not particularly limited, but examples thereof include titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, isocyanate coupling agents,
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 bromide and other halogenated zirconium, 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 the hydrogen-bonding group added is the ratio (K) of the number of moles (CN) of the cross-linking group of the cross-linking agent to the number of moles (HN) of the hydrogen-bonding group 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 not particularly limited,
Generally, the volume ratio of (inorganic layered compound / resin) is 5/95.
To 90/10, and more preferably the volume ratio is 5/95 to 50/50. Also, 5/95 to 30/70
In the range of 7, the flexibility of the film is improved, and 7/93 to 17/8
In the range of 3, there are advantages that the deterioration of the barrier property due to bending is small and the peel strength is strong. Also,
When the volume fraction of the inorganic layered compound is smaller than 5/95,
The barrier performance is not sufficient, and if it exceeds 90/10, the film-forming property is not good.

The method of blending the composition comprising the inorganic layered compound and the resin is not particularly limited, but, for example, a solution in which the resin is dissolved and a dispersion in which the inorganic layered compound is swollen and cleaved in advance are mixed and then the solvent is used. , A method of removing the swelling / cleavage of the inorganic layered compound is added to the resin, a method of removing the solvent, the inorganic layered compound is added to the solution in which the resin is dissolved, and a swelled / cleaved dispersion is prepared. Examples thereof include a method of removing, a method of thermally kneading a resin and an 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 two 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. In addition, the water resistance effect here is remarkably high when the resin is a high hydrogen-bonding resin, and when the inorganic layered compound is a clay mineral having a swelling property.

The polyolefin-based resin layers A and B used in the present invention refer to films obtained by extrusion-molding methods such as inflation-molding method and T-die molding method, and may be a single layer or multiple layers. The film thickness is not particularly limited, but is preferably 1 μm or more. Moreover, each layer may be stretched.

The resin used in the polyolefin resin layers A and B of the present invention is a homopolymer or copolymer containing an alpha olefin, such as polypropylene, polyethylene (high density, low density), ethylene-vinyl acetate copolymer. ,
Ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-butene copolymer, ethylene-hexene copolymer , Ethylene-4-methyl-1-pentene copolymer, ethylene-octene copolymer, ethylene-propylene copolymer, and the like.

Either one of the polyolefin resin layers A and B (layer B) of the present invention is preferably a non-stretched layer for the purpose of imparting heat-sealing property during bag making. When the other layer (A layer) is an outer layer, it is preferably a polyolefin resin layer that has been stretched, especially biaxially stretched, such as biaxially oriented polypropylene, from the viewpoint of strength and gloss.

The method for laminating the laminated film of the present invention is not particularly limited. In order to laminate a layer containing an inorganic layered compound on a polyolefin resin layer, a coating method of applying a coating liquid of a composition containing an inorganic layered compound and a resin on a substrate surface, drying, and heat treatment, including an inorganic layered compound A method of laminating a layer later, a method of extruding and laminating a polyolefin resin layer on a layer containing an inorganic layered compound, and the like are 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 film thickness of the layer containing the inorganic stratiform compound is not particularly limited, but is preferably 10 μm or less in dry thickness, more preferably 1 μm or less (when 1 μm or less, the transparency of the laminate is remarkably high). 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 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.

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 thereof.

[0033]

According to the present invention, a resin and an inorganic layered compound are provided between the polyolefin resin layers A and B.
The particle size of the inorganic layered compound is 5 μm or less, and the aspect ratio is 5
By stacking layers using 0 or more and 5000 or less, it becomes possible to obtain a laminated film having unprecedented high level moisture resistance and gas barrier property.

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, processed fish 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. , Is used for a wide range of purposes.

[0035]

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
10 / 50A, manufactured by MOCON Co., Ltd., and measured at a temperature of 30 ° C. (humidity-controlled thermostat 20 ° C.) (relative humidity showed about 60%). [Moisture vapor transmission rate]: Performed by the cup method under the conditions of 40 ° C. and relative humidity difference of 90% RH (JIS Z0208). [Thickness measurement]: 0.5 μm or more was measured with 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 [Particle size measurement]: Measured under the conditions of ultrafine particle size analyzer (BI-90, manufactured by Brookhaven Co., Ltd.), temperature of 25 ° C., and 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] Synthetic mica (Tetrasilicic mica (NA-TS); manufactured by Topy Industries, Ltd.) was dispersed in ion-exchanged water (0.7 µS / cm or less) at 0.65 wt%, This is referred to as an inorganic layered compound dispersion liquid (liquid A). The particle size of the synthetic mica (NA-TS) is 977n.
m, the a value obtained from powder X-ray diffraction is 0.9557 nm, and the aspect ratio Z is 1043. In addition, polyvinyl alcohol (PVA117H; manufactured by Kuraray Co., Ltd., saponification degree; 99.6%, degree of polymerization 1700) was added to ion-exchanged water (0.7 μS / cm).
The following) is dissolved to 0.325 wt% and this is used as a resin solution (solution B). Liquid A and liquid B were mixed so that the solid component ratio (volume ratio) was inorganic layered compound / resin = 3/7, and this was used as a coating liquid. 20 μm thickness
After the corona treatment of the biaxially stretched polypropylene film (Pyrene film OT manufactured by Toyobo), the composition liquid was gravure coated (test coater; Yasui Seiki Co., Ltd .: micro gravure coating method, coating speed 3 m / min, Drying temperature 80 ℃
(Inlet side heater) 100 ° C. (Outlet side heater)). The dry thickness of the coating layer was 0.8 μm. Furthermore, a urethane-based adhesive (Sanyo Kasei: Eunoflex J3) was used in the layer containing the inorganic layered compound of the obtained film to obtain an unstretched polypropylene film (Toyobo: Pyrene film CT thickness).
60 μm) was dry-laminated to obtain the laminated film of the present invention. The oxygen permeability of this laminated film at 30 ° C. and 60% RH was 0.1 cc / m ² / day or less, and the moisture permeability was good.

[Examples 2 to 6] Polyolefin resin layers A, B, inorganic layered compound, resin of inorganic layered compound layer, ratio of inorganic layered compound to resin, crosslinking agent for hydrogen bonding group, heat treatment after film formation A laminated film was produced by the method of Example 1 under the conditions shown in Table 1 and the oxygen permeability test was conducted. As shown in Table 1, the results were excellent in oxygen barrier properties and moisture resistance.

Example 7 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 the 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. An oxygen permeability test was conducted in the same manner as in Example 1 except that the other configurations were as shown in Table 1. The results were excellent in oxygen barrier properties and moisture resistance as shown in Table 1.

[Example 8] As a hydrogen-bonding group-crosslinking agent, zirconium ammonium carbonate (Zircozol AC7 manufactured by Daiichi Rare Element Industry Co., Ltd. (aqueous solution containing 15 wt% in terms of zirconium oxide)) was used as the hydroxyl group of polyvinyl alcohol in an amount of 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 the film was formed in the same manner as in Example 1 except that the constitution was as shown in Table 1, the film was heat-treated at 120 ° C. for 1 minute. As a result of the oxygen permeability test, as shown in Table 1, it was excellent in oxygen barrier property and moisture resistance.

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that the layer containing the inorganic stratiform compound was not used, and the oxygen permeability test and moisture permeability were measured. The result is 30 ℃, 60%
Oxygen permeability in RH is over 500cc / m ² / day,
The oxygen permeability was extremely poor.

[Comparative Example 2] Polyolefin resin layer A,
The same procedure as in Example 1 was carried out except that a biaxially stretched polyethylene terephthalate film (manufactured by Toray: Lumirror) having a thickness of 25 μm was used instead of B, and a biaxially stretched nylon film (manufactured by Unitika: Emblem) was 25 μm. As a result, the water vapor permeability was 20 g / m ² · day, and the moisture resistance was poor.

[0043]

[Table 1] Abbreviation CPP: Polypropylene film (Toyobo: product name Pyrene film CT) LL: Ethylene-butene copolymer film (Kite Chemical Industry: product name Kaitramimate L) HM: Ionomer film (Tama Poly: product name Tamapoly ionomer film HM) EVA : Ethylene-vinyl acetate copolymer film (manufactured by Kite Chemical Co., Ltd .: product name Kaitramimate E) LD: low-density polyethylene film (manufactured by Kite Chemical Industry: product name Kaitramimate S) OPP: biaxially oriented polypropylene film (manufactured by Toyobo:
Product name Pyrene film OT) NA: Tetrasilylic mica micronized product (Topy Industries:
Product name NaTs) F: Natural montmorillonite (Kunimine Industries: Product name Kunipia F) Particle size / a value / Z = 560 nm / 1.2156 nm
/ 461 H: Polyvinyl alcohol (Kuraray: Poval 117
H, degree of polymerization 1700, degree of saponification 99.6 mol%) Z: ammonium zirconium carbonate aqueous solution (manufactured by Daiichi Rare Element Industry: Zircosol AC7) A: heat treatment of laminated film (after drying) at 120 ° C. for 1 minute

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a layer structure of a moisture-proof laminated film of the present invention.

FIG. 2 is a conceptual diagram showing the layer structure of the moisture-proof laminated film of the present invention.

FIG. 3 is a conceptual diagram showing the layer structure of the moisture-proof laminated film of the present invention.

FIG. 4 is a conceptual diagram showing the layer structure of the moisture-proof 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. 6) of a composition having an interplanar spacing d of 44.13 Å or more.

[Explanation of symbols]

 1 Layer Containing Inorganic Layered Compound 2 Polyolefin Resin Layer A 3 Polyolefin Resin Layer B 4 Other Laminating Substrate

─────────────────────────────────────────────────── ─── 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 (12)

[Claims] 1. At least a layer comprising a resin composition characterized by containing 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 between polyolefin resin layers A and B. A moisture-proof laminated film having one layer. 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 (5
/ 95) to (90/10). 5. The laminated film according to claim 1, wherein the laminated film is in the range of / 95) to (90/10). 6. The laminated film according to claim 1, wherein the resin is a high hydrogen-bonding resin. 7. The laminated film according to claim 6, wherein the high hydrogen-bonding resin has a weight percentage of hydrogen-bonding groups or ionic groups per unit weight of resin of 30% or more and 50% or less. . 8. The laminated film according to claim 6, wherein the high hydrogen-bonding resin is polyvinyl alcohol or polysaccharide. 9. The laminated film according to claim 6, wherein the resin composition containing the inorganic layered compound contains a crosslinking agent for hydrogen-bonding groups. 10. The laminated film according to claim 9, wherein the crosslinking agent for hydrogen-bonding groups is a zirconia compound. 11. A laminate having at least one layer of the laminated film according to any one of claims 1 to 10. 12. The laminate according to claim 1, which has an oxygen permeability of 0.2 cc / m ² · day · atm or less at 30 ° C. and 60% RH. Film or laminate.