JP2008200975A - Method for producing multilayer structure - Google Patents

Abstract

A multilayer structure in which a layer made of a resin composition containing an inorganic stratiform compound is laminated on a metal vapor-deposited layer, wherein the multilayer structure has excellent gas barrier properties, particularly gas barrier properties under high humidity conditions. A manufacturing method is provided.
A base material layer, a first layer made of metal and / or metal oxide formed on at least one surface of the base material layer, and adjacent to the first layer, a resin and The manufacturing method of a multilayer structure which has a 2nd layer formed from the resin composition containing an inorganic layered compound, Comprising: The manufacturing method of a multilayer structure which contains the following processes (1) and (2) in order.
(1) A step of forming a first layer on the base material layer by subjecting a metal and / or metal oxide to vapor deposition treatment (2) including a resin, an inorganic layered compound and a liquid medium, and having a pH of 7 to 14 A step of applying a coating liquid onto the first layer and then removing the liquid medium to form a second layer on the first layer.

Description

  The present invention relates to a method for producing a multilayer structure.

  Conventionally, molded articles made of thermoplastic resins such as polypropylene, polyester and polyamide are used in many fields such as food, cosmetics, agricultural chemicals and medical fields due to their excellent mechanical properties, heat resistance and transparency. Widely used as packaging material. In the case where a thermoplastic resin molded body is used as a packaging material, gas barrier properties are often required in order to prevent the contents from being deteriorated by oxygen. As a packaging material having such a gas barrier property, for example, Patent Document 1 discloses a gas barrier property in which an overcoat layer made of a resin composition containing an inorganic layered compound is laminated on a vapor deposition layer of a metal vapor deposition base film. A film is disclosed.

JP 2003-260750 A

  However, as described above, a gas barrier film in which a layer made of a resin composition containing an inorganic stratiform compound is laminated on a metal vapor deposition layer has insufficient gas barrier properties, particularly under high humidity conditions. It was.

  As a result of intensive studies, the present inventors can obtain a multilayer structure excellent in gas barrier properties, particularly gas barrier properties under high humidity conditions, by adjusting the pH of the coating liquid used for forming the overcoat layer. As a result, the inventors have reached the present invention.

That is, the present invention provides a base material layer, a first layer formed of metal and / or metal oxide formed on at least one surface of the base material layer, and adjacent to the first layer. And a second layer formed from a resin composition containing an inorganic layered compound, the method for producing a multilayer structure comprising the following steps (1) and (2) in order: is there.
(1) A step of forming a first layer on the base material layer by subjecting a metal and / or metal oxide to vapor deposition treatment (2) including a resin, an inorganic layered compound and a liquid medium, and having a pH of 7 to 14 Applying a coating liquid onto the first layer and then removing the liquid medium to form a second layer on the first layer;

  According to the method for producing a multilayer structure of the present invention, a multilayer structure having excellent gas barrier properties, particularly gas barrier properties under high humidity conditions can be produced.

  The present invention provides a multilayer structure comprising a base material layer, a first layer comprising a metal and / or a metal oxide, and a second layer formed from a resin composition containing a resin and an inorganic layered compound. Is the method.

The 1st layer in this invention is a layer formed on a base material layer by carrying out the vapor deposition process of a metal and / or a metal oxide. The metal and / or metal oxide in the first layer is not particularly limited, but examples of the metal include aluminum, silicon, titanium, and zinc. Examples of the metal oxide include oxidation of each metal described above. Of these, aluminum and / or aluminum oxide is preferably used. Two or more kinds of metal and / or metal oxide may be used in combination, and the oxidation state of the metal oxide may be various.

A method of forming the first layer on the base material layer is a method of vapor-depositing metal and / or metal oxide, and specifically includes a vacuum vapor deposition method, a CVD method, a sputtering method, and the like. The method for forming the first layer is preferably a vacuum deposition method or a CVD method.

The second layer in the present invention includes an inorganic layered compound, a resin and a liquid medium, and is formed by applying a coating liquid having a pH of 7 to 14 onto the first layer and then removing the liquid medium. Is done. The inorganic layered compound used in the present invention refers to a product in which unit crystal layers are stacked to form a layered structure before being dispersed in a liquid medium. A layered structure is a structure in which atoms that are strongly bonded by a covalent bond or the like and densely arranged are stacked almost in parallel by a weak binding force such as van der Waals.
Among inorganic layered compounds, clay minerals having swelling property to a solvent are particularly preferably used.

  Clay minerals generally include (i) a type having a two-layer structure having an octahedral layer with aluminum, magnesium, etc. as a central metal above the silica tetrahedral layer, and (ii) the silica tetrahedral layer is made of aluminum. And a type having a three-layer structure in which an octahedral layer having a central metal such as magnesium is sandwiched from both sides. Examples of the two-layer structure type clay mineral (i) include kaolinite group and antigolite group clay minerals. Examples of the clay mineral of the three-layer structure type (ii) include clay minerals such as smectite group, vermiculite group, and mica group depending on the number of interlayer cations.

  These clay minerals include kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, hectorite, tetrasilic mica, sodium tenio. Light, muscovite, margarite, talc, vermiculite, phlogopite, xanthophyllite, chlorite and the like. In addition, organically modified clay minerals obtained by treating these clay minerals with an organic agent such as ion exchange and improving dispersibility can also be used as alkali metal ion donating compounds (for types and production methods of organically modified clay minerals). For example, see Masahiro Maeno, “Science of Clay”, 174-181, 1993, Nikkan Kogyo Shimbun). Examples of the organic agent include quaternary ammonium salts such as dimethyl distearyl ammonium salt and trimethyl stearyl ammonium salt, phosphonium salts, imidazolium salts and the like.

  Among the clay minerals, smectite group, vermiculite group and mica group clay minerals are preferable, and smectite group is particularly preferable. Examples of the smectite group include montmorillonite, beidellite, nontronite, saponite, soconite, stevensite, and hectorite. The inorganic layered compound in the present invention is most preferably montmorillonite. Two or more kinds of inorganic layered compounds may be used.

  The aspect ratio of the inorganic stratiform compound used for forming the second layer is preferably in the range of 200 to 10,000, and more preferably in the range of 200 to 5000. By using an inorganic layered compound having such an aspect ratio, a multilayer structure having more excellent gas barrier properties can be obtained.

  The average particle size of the inorganic layered compound is preferably 30 μm or less. The multilayer structure having the second layer containing the inorganic layered compound having such an average particle diameter is excellent in gas barrier properties. Moreover, it is excellent also in film forming property by using the inorganic layered compound of such an average particle diameter. In the case where the multilayer structure obtained in the present invention is used for an application in which transparency is particularly required, the average particle size of the inorganic layered compound contained in the second layer is preferably 1 μm or less.

  The aspect ratio (Z) of the inorganic layered compound described above is a value defined by Z = L / a. Here, L is the average particle diameter of the inorganic layered compound, a is the unit thickness of the inorganic layered compound, that is, the thickness of the unit crystal layer of the inorganic layered compound, and is determined by powder X-ray diffraction (“instrumental analysis”). No. (a) "(1985, published by Kagaku Dojinsha, supervised by Jiro Shiokawa, p. 69).

  The average particle diameter of the inorganic layered compound in the present invention is the particle diameter (volume-based median diameter) obtained by diffracting / scattering the inorganic layered compound in the same liquid medium as the liquid medium contained in the coating liquid. It is. Specifically, 30 g of the inorganic layered compound is gradually added to 1,500 ml of the liquid medium, and a disperser (manufactured by Asada Tekko Co., Ltd., Despa MH-L, blade diameter 52 mm, rotation speed 3,100 rpm, container capacity 3 L, bottom surface -From the diffraction / scattering pattern obtained when light is passed through a dispersion liquid dispersed at a peripheral speed of 8.5 m / min and a temperature of 90 ° C. for 90 minutes at a distance of 28 mm between blades, The average particle size of the inorganic layered compound can be determined by calculating the particle size distribution that is most consistent with the diffraction / scattering pattern. For example, there is a method in which the measurement range of the particle size distribution is divided into appropriate sections, the representative particle diameter is determined for each section, and the particle size distribution, which is originally a continuous quantity, is converted into a discrete quantity for calculation.

  As the inorganic layered compound used for forming the second layer, those having a swelling value of 5 or more and more preferably 20 or more by the following swellability test are more preferred. Further, those having a cleavage value of 5 or more by cleavage test described below are preferred, and those having a cleavage value of 20 or more are more preferred.

(Swellability test)
Into a 100 ml graduated cylinder, 100 ml of liquid medium is added, and 2 g of inorganic layered compound is gradually added thereto. After standing at 23 ° C. for 24 hours, the volume (ml) of the inorganic layered compound dispersion layer is read from the scale of the interface between the inorganic layered compound dispersion layer and the supernatant in the graduated cylinder. It shows that swelling property is so high that this numerical value (swelling value) is large.

[Cleavage test]
Gradually add 30 g of inorganic layered compound into 1,500 ml of liquid medium, disperser (Asada Tekko Co., Ltd., Despa MH-L, blade diameter 52 mm, rotation speed 3,100 rpm, container volume 3 L, distance between bottom surface and blades 28 mm) at a peripheral speed of 8.5 m / min and at 23 ° C. for 90 minutes, 100 ml of this dispersion is collected in a graduated cylinder. After standing for 60 minutes, the volume (ml) of the inorganic layered compound dispersion layer is read from the scale of the interface between the layered compound dispersion layer and the supernatant in the graduated cylinder. The larger this numerical value (cleavage value), the higher the cleavage property.

The coating liquid used for forming the second layer in the present invention contains a resin. Examples of the resin include ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), polysaccharides, polyacrylic acid and esters thereof, and urethane resins.
The resin is preferably a resin having a hydroxyl group from the viewpoint of easy dissolution in an aqueous liquid medium, easy handling, and gas barrier properties of the resulting multilayer structure. Examples of such a resin include PVA, EVOH, and cellulose.

  From the viewpoint of the gas barrier property of the multilayer structure, the resin used for forming the second layer is (i) a resin having a hydroxyl group and a second functional group capable of reacting with the hydroxyl group in one molecule; Or (ii) It is preferable that it is a mixture of resin which has a hydroxyl group, and resin which has the 2nd functional group which can react with a hydroxyl group. Hereinafter, the case of (i) and the case of (ii) may be collectively referred to as “resin component having a hydroxyl group and a second functional group”.

  The second functional group capable of reacting with the hydroxyl group is preferably a polar group such as a carboxyl group, an amino group, a sulfonic acid group, a carboxylate group, or an ammonium group, and the hydroxyl group and the second functional group are shared with each other. It is preferable that a bond or an ionic bond can be formed.

Examples of the resin containing a hydroxyl group and a second functional group in one molecule include vinyl alcohol-acrylic acid copolymer, vinyl alcohol-methacrylic acid copolymer, vinyl alcohol-vinylamine copolymer, acrylic acid-vinylamine copolymer. And a methacrylic acid-vinylamine copolymer.

Examples of the resin having a second functional group capable of reacting with a hydroxyl group include polyacrylic acid, polymethacrylic acid, polyvinylamine, acrylic acid-methacrylic acid copolymer, vinylamine- (meth) acrylic acid copolymer, and the like. Can be mentioned.

When the resin used to form the second layer is a mixture of a resin having a hydroxyl group and a resin having a second functional group capable of reacting with the hydroxyl group, the resin having a hydroxyl group is polyvinyl alcohol. The resin having a second functional group capable of reacting with a hydroxyl group is preferably polyacrylic acid and / or polymethacrylic acid.

Polyvinyl alcohol is a polymer having a monomer unit of vinyl alcohol as a main component. Such “polyvinyl alcohol” includes, for example, a polymer obtained by hydrolyzing the acetate portion of a vinyl acetate polymer (exactly a copolymer of vinyl alcohol and vinyl acetate, trifluoroacetic acid Examples include polymers obtained by hydrolyzing vinyl polymers, vinyl formate polymers, vinyl pivalate polymers, tert-butyl vinyl ether polymers, trimethylsilyl vinyl ether polymers, etc. (For details of “polyvinyl alcohol”, for example, Edited by Poval Association, “World of PVA”, 1992, Kobunshi Publishing Co., Ltd .; Nagano et al., “Poval”, 1981, Kobunshi Publishing Co., Ltd. can be referred to.) “Polyvinyl alcohol” The degree of saponification is preferably 70 mol% or more, more preferably 85 mol% or more. Properly, further 98% molar or more so-called completely saponified products preferred. The polymerization degree of 100 to 5000, more preferably 200 to 3,000.

  The polyacrylic acid in the present invention includes a partially neutralized polyacrylic acid. Polymethacrylic acid includes a partially neutralized polymethacrylic acid. The weight average molecular weights of polyacrylic acid and polymethacrylic acid are each preferably in the range of 2,000 to 10,000,000, more preferably 100,000 to 5,000,000.

The partially neutralized polyacrylic acid can be usually obtained by adding an alkali to an aqueous solution of polyacrylic acid. A desired degree of neutralization can be achieved by adjusting the amount ratio of polyacrylic acid and alkali. Here, the degree of neutralization of polyacrylic acid is defined by the following equation. The partially neutralized polyacrylic acid preferably has a degree of neutralization of 0.1% to 20% from the viewpoint of gas barrier properties and transparency of the multilayer structure.
Degree of neutralization = (A / B) × 100
A: Number of moles of neutralized carboxyl group contained in 1 g of polyacrylic acid B: Number of moles of carboxyl group before neutralization contained in 1 g of polyacrylic acid The same applies to neutralized polymethacrylic acid It is.

  When the resin used to form the second layer is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the hydroxyl group and carboxyl contained in the resin component The molar ratio of the groups is preferably hydroxyl group: carboxyl group = 30: 70 to 95: 5, more preferably 70:30 to 95: 5. From the viewpoint of gas barrier properties under high humidity conditions of the obtained multilayer structure, when the weight of the resin component is 100%, the total weight of hydroxyl groups and carboxyl groups contained in the resin component is 30 to 60%. It is preferable that it is 35 to 55%.

  The molar ratio of the hydroxyl group to the carboxyl group in the resin component can be determined by NMR method, IR method or the like. For example, in the case of the IR method, a calibration curve is obtained using a sample having a known molar ratio of hydroxyl group to carboxyl group, and the number ratio between the hydroxyl group and carboxyl group of the measurement sample can be calculated using this. When using vinyl alcohol homopolymer and acrylic acid monopolymer and / or methacrylic acid monopolymer, the number of moles of hydroxyl group and carboxyl group is obtained in advance from the weight, and the number ratio of hydroxyl group to carboxyl group is calculated. can do. Further, the total weight measurement of the hydroxyl group and carboxyl group contained in the resin component can be determined by NMR method, IR method, etc., as in the molar ratio. For example, in the IR method, a calibration curve is obtained for a polyol polymer having a known number of polyol units and a polycarboxylic acid polymer having a known number of polycarboxylic acid units, and using these calibration curves, a hydroxyl group in a measurement sample is obtained. And the total weight of carboxyl groups can be calculated. Moreover, when using a vinyl alcohol single polymer and an acrylic acid single polymer and / or a methacrylic acid single polymer, the weight of a hydroxyl group and a carboxyl group can be calculated | required from the weight previously, and this total amount can be calculated | required.

  When the resin used to form the second layer is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, from the viewpoint of water resistance of the multilayer structure, The second layer preferably contains alkali metal ions. Examples of alkali metal ions include sodium ions, lithium ions, and potassium ions. The weight of the alkali metal ions contained in the second layer is preferably 0.2 to 5 parts with respect to 100 parts by weight of the resin when the weight of the resin contained in the second layer is 100 parts. More preferably, it is 0.2-2 parts.

The alkali metal ion is usually derived from an alkali metal ion donating compound. That is, when the resin contained in the second layer is a resin component having a hydroxyl group and a second functional group, and the second functional group is a carboxyl group, the second layer contains an alkali metal ion donating compound. Is preferred. Examples of the alkali metal ion donating compound include sodium hydroxide, sodium hypophosphite, lithium hydroxide, potassium hydroxide and the like. Further, when the inorganic layered compound contained in the second layer is montmorillonite, sodium ions are contained between the montmorillonite layers, so that montmorillonite acts as an alkali metal ion donating compound. Therefore, the inorganic layered compound contained in the second layer is particularly preferably montmorillonite. Two or more alkali metal ion donor compounds may be used in combination.

  The liquid medium contained in the coating liquid used for forming the second layer is preferably a liquid medium that swells and cleaves the inorganic layered compound to be used. When the inorganic layered compound is a hydrophilic swellable clay mineral, water, alcohols (methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, etc.), dimethylformamide, dimethyl sulfoxide, acetone, etc. Water, alcohol and water-alcohol mixtures are preferred.

  When the inorganic layered compound is an organically modified clay mineral, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as ethyl ether and tetrahydrofuran, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, n -Aliphatic hydrocarbons such as pentane, n-hexane, n-octane, halogenated hydrocarbons such as chlorobenzene, carbon tetrachloride, chloroform, dichloromethane, 1,2-dichloroethane, perchloroethylene, ethyl acetate, methacrylic acid Methyl, dioctyl phthalate, dimethylformamide, dimethyl sulfoxide, methyl cellosolve, silicone oil, and the like can be used as the liquid medium of the coating liquid.

  The coating liquid used for forming the second layer includes a resin, an inorganic layered compound, and a liquid medium. The coating solution can be adjusted by the following method. For example, a method of mixing a resin solution obtained by dissolving a resin in a liquid medium and a dispersion of the inorganic layered compound that has been previously swollen and cleaved with the inorganic layered compound, or a method in which the inorganic layered compound is previously swollen and cleaved into the liquid medium. Examples thereof include a method in which a resin is directly mixed into the dispersion liquid of the inorganic layered compound and a method in which the resin solution and the inorganic layered compound are mixed. When preparing the coating liquid, the liquid containing the resin and the inorganic layered compound may be subjected to a high-pressure dispersion treatment as described later, or the inorganic layered compound dispersion previously subjected to the high-pressure dispersion treatment and the resin. You may mix by the above-mentioned method.

When adjusting the coating liquid which forms a 2nd layer, it is preferable to carry out a high voltage | pressure dispersion process using a high voltage | pressure dispersion apparatus from the viewpoint of the dispersibility. Examples of the high-pressure dispersing device include an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation, a nanomizer manufactured by Nanomizer, a Manton Gorin type high-pressure dispersing device, and a homogenizer manufactured by Izumi Food Machinery. The high-pressure dispersion treatment is a method in which a liquid containing an inorganic layered compound is passed through a plurality of thin tubes at a high speed and then merged to collide the liquids containing the inorganic layered compound with each other or the liquid and the inner wall of the thin tube. This is a processing method of applying high shear and / or high pressure to a liquid containing a layered compound. In the high-pressure dispersion treatment, it is preferable that the coating liquid is passed through a narrow tube having a tube diameter of about 1 μm to 1000 μm, and at this time, treatment is performed so that a maximum pressure of 100 kgf / cm ² or more is applied. Maximum pressure is more preferably at 500 kgf / cm ² or more, and particularly preferably 1000 kgf / cm ² or more. When the liquid containing the inorganic layered compound passes through the narrow tube, the maximum arrival speed of the liquid is preferably 100 m / s or more, and the heat transfer speed due to pressure loss is preferably 100 kcal / hr or more.

  The pH of the coating solution used for forming the second layer is 7 to 14, preferably 7 to 13, and more preferably 8 to 13. By setting the pH of the coating solution within this range, a multilayer structure excellent in gas barrier properties, particularly gas barrier properties under high humidity conditions can be obtained.

As a method of adjusting the pH of the coating solution, a known method can be used, but a method of adding a basic additive such as sodium hydroxide or a method of using an ion exchange resin is preferable.

  The resin contained in the coating solution is a crosslinkable reaction such as hydroxyl group, amino group, thiol group, carboxyl group, sulfonic acid group, phosphoric acid group, carboxylate group, sulfonic acid ion group, phosphate ion group, ammonium group, phosphonium group, etc. In the case of a resin having a group, a crosslinking agent may be added to the coating solution. Examples of crosslinking agents used include titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, isocyanate coupling agents, carbodiimide coupling agents, copper compounds, and zirconium compounds. Can be mentioned. Only one kind of these crosslinking agents may be used, or two or more kinds may be appropriately mixed and used.

When a crosslinking agent is added to the coating solution, it is usually adjusted by a method in which a crosslinking agent solution in which 10 to 90% by weight of a crosslinking agent is previously dissolved in a solvent such as alcohol is added to the coating solution. .

  It is preferable to add a surfactant to the coating solution. By applying the coating solution containing a surfactant to form a layer, adhesion between the layer and a layer adjacent to the layer can be improved. The content of the surfactant is usually 0.001 to 5% by weight in 100% by weight of the coating liquid.

  As the surfactant, a known surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be used. In particular, an alkali metal salt of a carboxylic acid having an alkyl chain of 6 to 24 carbon atoms, an ether type nonionic surfactant such as a polydimethylsiloxane-polyoxyethylene copolymer (silicone-based nonionic surfactant) Agent) and fluorine-type nonionic surfactants (fluorine-based nonionic surfactants) such as perfluoroalkylethylene oxide compounds are preferable from the viewpoint of improving adhesion between layers.

  Each layer constituting the multilayer structure obtained in the present invention may contain various additives such as an ultraviolet absorber, a colorant, an antioxidant, and the like as long as the effects of the present invention are not impaired. .

  The ratio of the inorganic layered compound and the resin contained in the coating solution is preferably 5 to 95% when the total volume of the inorganic layered compound and the resin is 100%. % Is more preferable, 10 to 50% is more preferable, and 20 to 50% is most preferable. The proportion of the resin is preferably 5 to 95%, more preferably 50 to 95%, more preferably 50 to 90%, and most preferably 50 to 80%.

  The material which comprises the base material layer in this invention is not specifically limited, A metal, resin, wood, ceramic, glass, etc. are mentioned. The form of the base material layer is not particularly limited, and examples thereof include paper, cloth, nonwoven fabric, and film. As the resin, a thermoplastic resin or a thermosetting resin can be used. When using the multilayer structure obtained by this invention as a packaging material, it is preferable that a base material layer is comprised from a thermoplastic resin. The thermoplastic resin used is low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer. Polypropylene (PP), ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, polyolefin resin such as ionomer resin, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, nylon-6 ( Ny-6), nylon-6,6, polyxylenediamine-adipic acid condensation polymer, amide resins such as polymethylmethacrylamide, acrylic resins such as polymethylmethacrylate, polystyrene, styrene-acrylonitrile Copolymers, styrene-acrylonitrile-butadiene copolymers, styrene-acrylonitrile resins such as polyacrylonitrile, hydrophobized cellulose resins such as cellulose triacetate and cellulose diacetate, halogens such as polyvinyl chloride, polyvinylidene chloride, and polyvinylidene fluoride -Containing resin, 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, etc. Is given. Examples of the thermosetting resin include known phenol resins, melamine resins, urea resins and the like. When the multilayer structure obtained in the present invention is a film, the base material layer may be any of an unstretched film, a uniaxially stretched film, and a biaxially stretched film. It is preferable that it is a biaxially stretched film which consists of either. The base material layer may be a multilayer film such as Ny-6 / MXD6-Ny / Ny-6 or PP / EVOH / PP.

  The base material layer may be laminated adjacent to the first layer, or may be laminated via another layer such as an adhesive layer. The first layer may be provided on one surface or both surfaces of the base material layer, or may be provided on a part or the entire surface of the base material layer.

  As a method of providing the anchor coat layer and the second layer by coating, a gravure method such as a direct gravure method and a reverse gravure method, a roll coating method such as a two roll beat coat method, a bottom feed three reverse coat method, a doctor knife Method, die coating method, bar coating method, dipping method, spray coating method. Further, an additional layer and a resin layer to be described later can be provided by the same method. When the multilayer structure is a film, it is preferable to employ a gravure method because a layer having a uniform thickness can be provided.

  The thickness of each layer which comprises the multilayer structure obtained by this invention is not specifically limited. The thicknesses of the first layer and the second layer are usually 1 nm to 10 μm, preferably 1 nm to 1 μm, and more preferably 1 nm to 500 nm from the viewpoint of gas barrier properties and cost. The multilayer structure obtained by the present invention has sufficient gas barrier properties even when the first layer and the second layer are thin as described above. From the viewpoint of bending resistance, the thickness of the second layer is preferably equal to the thickness of the first layer or thicker than the first layer. The thicknesses of the additional layer and resin layer described later are also usually 1 nm to 10 μm. When the anchor coat layer is provided on the base material layer, the thickness of the anchor coat layer is usually 0.01 to 5 μm.

The multilayer structure obtained in the present invention may have a layer other than the first layer, the second layer, and the base material layer, and each of the layers having the same composition as the first layer and the second layer. You may have multiple layers. As the configuration of the multilayer structure, for example, base material layer / first layer / second layer (configuration 1),
Base layer / first layer / second layer / additional layer A (Configuration 2),
Base layer / first layer / second layer / additional layer B / additional layer C (Configuration 3),
Base layer / first layer / second layer / additional layer D / additional layer E / additional layer F (configuration 4),
Base material layer / first layer / second layer / resin layer (Configuration 5),
Base layer / first layer / second layer / additional layer B / additional layer C / resin layer (configuration 6),
Base material layer / first layer / second layer / addition layer D / addition layer E / addition layer F / resin layer (Configuration 7)
Is mentioned.
Here, the additional layers A, B, C, D, and E may have the same composition as the first layer or the second layer, respectively. For example, in the configuration 2, the additional layer A may have the same composition as the first layer, and in the configuration 3, the additional layer B may have the same composition as the first layer and the additional layer C may have the same composition as the second layer. . In the configuration 4, the additional layers D and F may have the same composition as the first layer, and the additional layer E may have the same composition as the second layer.

The multilayer structure obtained by the present invention is preferably subjected to a dry heat treatment in which the water vapor concentration is kept in an atmosphere having a water vapor concentration of less than 50 g / m ³ at a temperature of 100 ° C. or higher before use from the viewpoint of improving gas barrier properties. The dry heat treatment temperature is preferably 120 ° C. or higher and 200 ° C. or lower. The time for the dry heat treatment is usually 1 second to 1 hour. The water vapor concentration during the dry heat treatment is preferably 0 to 40 g / m ³ . The heat source used for the dry heat treatment is not particularly limited, and various methods such as hot roll contact, heat medium contact (air, etc.), infrared heating, microwave heating and the like can be applied.

In the multilayer structure obtained by the present invention, when the resin contained in the second layer is a resin component containing a hydroxyl group and a carboxyl group, it is preferable to perform a wet heat treatment after the dry heat treatment, and further dry the resin. . The wet heat treatment is a treatment of holding in an atmosphere having a water vapor concentration of more than 290 g / m ³ at a temperature of 100 ° C. or higher or in water having a temperature of 80 ° C. or higher. The time for the wet heat treatment is usually 1 second to 1 hour. If the water vapor concentration at 100 ° C. above the temperature of the treatment in an atmosphere of 290 g / m ³ greater, the temperature is preferably in the range of 120 to 200 [° C., the water vapor concentration is preferably in the range of 500~20000g / m ^3. Before the wet heat treatment, the dry heat-treated resin film may be aged, for example, at 23 ° C. and 50% RH. Specific treatment methods for the wet heat treatment include a method of aging in a water vapor atmosphere and a method of immersing the multilayer structure in hot water. The time for the wet heat treatment is usually 1 second to 1 hour. The drying treatment after the wet heat treatment is performed to remove moisture given to the multilayer structure by the wet heat treatment. Usually, the resin film is held at a humidity of 50% RH or less and a temperature of 20 to 100 ° C. for 1 second to 24 hours. Further, the multilayer structure subjected to the dry heat treatment may be aged, for example, under a condition of 23 ° C. and 50% RH before the heat treatment.

Examples of the multilayer structure obtained by the present invention include tires and screws, optical component members such as flexible display substrates or sealing materials for liquid crystal displays, organic EL, substrates such as solar cells or dye-sensitized solar cells, sealing Examples thereof include electronic component members such as materials. For example, a coated screw obtained by laminating a first layer and a second layer on a metal screw is not easily deteriorated by oxygen. Thus, by stacking the first layer and the second layer on various conventional products that do not have the first layer and the second layer, a multilayer structure obtained in the present invention can be obtained. It is possible to suppress oxygen deterioration of a product that has been deteriorated due to the above. It can also be used as a vacuum insulation panel.
Further, by using the multilayer structure obtained in the present invention as a packaging material, it is possible to prevent oxygen deterioration of the contents packaged with the packaging material. When the multilayer structure is used as a packaging material, examples of the shape include a film, a bag, a pouch, a bottle, a bottle cap, a carton container, a cup, a plate, a tray, a tank, and a tube. Since the multilayer structure is excellent in barrier properties after retorting, it is particularly preferably used as a packaging material for retort. The contents packaged by the multilayer structure include cakes, pastries such as castella, Japanese sweets such as Daifuku and mochi, confectionery such as snacks such as potato chips, marine products such as bamboo rings and rice cakes, miso, pickles, Examples include foods such as rice cakes, meatballs, hamburgers, hams and sausages, beverages such as coffee, tea and juice, dairy products such as milk and yogurt, cooked rice and curry. In addition to food products, toiletries such as detergents, baths, and cosmetics, fuels such as gasoline and hydrogen gas, pharmaceuticals and medical devices such as powders, tablets, eye drops, and infusion bags, electronic components such as hard disks and silicon wafers, It can also be used as a packaging material for electronic devices.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Measurement methods for various physical properties are described below.

[Thickness measurement]
The thickness of 0.5 μm or more was measured using a commercially available digital thickness gauge (contact thickness gauge, trade name: ultra-high precision deci-micro head MH-15M, manufactured by Nippon Optical Co., Ltd.). The thickness of less than 0.5 μm was determined by cross-sectional observation with a transmission electron microscope (TEM).

(Particle size measurement)
Measurement was performed using a laser diffraction / scattering particle size distribution analyzer (LA910, manufactured by Horiba, Ltd.). The average particle size of the inorganic layered compound in the coating solution described later is measured with a paste cell at an optical path length of 50 μm, and the average particle size in the diluted solution of only the inorganic layered compound is measured with a flow cell method at an optical path length of 4 mm. did. In either case, the value of the average particle diameter did not change, and it was confirmed that the inorganic layered compound was sufficiently swollen and cleaved in the coating solution.

[Aspect ratio calculation]
Using an X-ray diffractometer (XD-5A, manufactured by Shimadzu Corporation), diffraction measurement of the inorganic layered compound was performed by the powder method, and the unit thickness a of the inorganic layered compound was determined. Using the average particle diameter L obtained by the above method, the aspect ratio Z of the inorganic layered compound was calculated by the formula Z = L / a. In addition, about the thing which dried the coating liquid, the X-ray-diffraction measurement was performed, and it was confirmed that the surface interval of an inorganic layered compound has spread.

(Oxygen permeability measurement)
Based on JIS K7126, measurement was carried out under the conditions of 30 ° C. 60% RH and 23 ° C. 90% RH with an ultrasensitive oxygen permeability measuring device (OX-TRANML, manufactured by MOCON).

[Preparation of coating solution]
Preparation of coating liquid (1) In a dispersion kettle (trade name: Despa MH-L, manufactured by Asada Tekko Co., Ltd.), 1300 g of ion-exchanged water (specific electric conductivity 0.7 μs / cm or less) and polyvinyl alcohol (PVA117H) Manufactured by Kuraray Co., Ltd., saponification degree: 99.6%, polymerization degree 1,700) and 130 g were mixed and heated to 95 ° C. under low speed stirring (1500 rpm, peripheral speed 4.1 m / min). The mixed system was stirred at the same temperature for 30 minutes to dissolve the polyvinyl alcohol, and then cooled to 60 ° C. to obtain an aqueous polyvinyl alcohol solution. While stirring the polyvinyl alcohol aqueous solution (60 ° C.) under the same conditions as described above, an alcohol aqueous solution obtained by mixing 122 g of 1-butanol, 122 g of isopropyl alcohol and 520 g of ion-exchanged water was added dropwise over 5 minutes. After completion of the dropping, switching to high-speed stirring (3,000 rpm, peripheral speed = 8.2 m / min), 65 g of high-purity montmorillonite (trade name: Kunipia G; manufactured by Kunimine Industries Co., Ltd.) was gradually added to the stirring system, After completion of the addition, stirring was continued at 60 ° C. for 60 minutes. Thereafter, 243 g of isopropanol was further added over 15 minutes, and then the mixed system was cooled to room temperature to obtain an inorganic layered compound-containing liquid (A). Non-ionic surfactant (polydimethylsiloxane-polyoxyethylene copolymer, trade name: SH3746, manufactured by Toray Dow Corning Co., Ltd.) 0.1% by weight based on the inorganic layered compound-containing liquid (A) ( Based on the weight of the containing liquid) was added to obtain an inorganic layered compound-containing liquid (B). Furthermore, this was processed on the conditions of 1100 kgf / cm < ² > using the high voltage | pressure dispersion apparatus (Brand name: Super high pressure homogenizer M110-E / H, Microfluidics Corporation make), and the inorganic layered compound dispersion liquid (1) was obtained. The cleaved montmorillonite average particle diameter in the inorganic layered compound dispersion (1) was 560 nm, the a value obtained from powder X-ray diffraction was 1.2156 nm, and the aspect ratio was 460. Moreover, the pH of the inorganic layered compound dispersion (1) was 6.
By slowly adding the inorganic layered compound dispersion (1) while adjusting with sodium hydroxide so that the pH of the system becomes 10 under low speed stirring (1500 rpm, peripheral speed 4.1 m / min). A coating liquid (1) was prepared. When the total volume of polyvinyl alcohol and the inorganic layered compound in the coating liquid (1) was 100%, the volume fraction of the inorganic layered compound was 20 vol%.

Preparation of coating liquid (2) A coating liquid (2) was prepared in the same manner as the coating liquid (1) except that the pH of the first dispersion was set to 8.

Preparation of coating liquid (3) A coating liquid (3) was prepared in the same manner as the coating liquid (1) except that the pH of the first dispersion was set to 2.

Preparation of coating liquid (4) A coating liquid (4) was prepared in the same manner as the coating liquid (1) except that 130 g of polyvinyl alcohol was used instead of 65 g of high-purity montmorillonite.

Preparation of coating liquid (5) An inorganic layered compound-containing liquid (C) was prepared in the same manner as the inorganic layered compound-containing liquid (B) except that 82 g of high-purity montmorillonite was used.
Furthermore, another dispersion kettle (trade name: Despa MH-L, manufactured by Asada Tekko Co., Ltd.), 1067 g of ion-exchanged water (specific electric conductivity 0.7 μs / cm or less) and polyacrylic acid (Wako Pure Chemical Industries, Ltd. (Made by Co., Ltd., average molecular weight 100,0000) was mixed with 33 g, and a resin component solution was prepared at room temperature under low speed stirring (1500 rpm, peripheral speed 4.1 m / min).
2519 g of the inorganic layered compound-containing liquid (C) and 1100 g of the resin component solution are gradually mixed under low speed stirring (1500 rpm, peripheral speed 4.1 m / min) to form a mixed liquid, and the mixed liquid is further mixed with a high-pressure dispersion device (product) Name: An ultra-high pressure homogenizer M110-E / H (manufactured by Microfluidics Corporation) was used under the condition of 1100 kgf / cm ² to obtain an inorganic layered compound dispersion (2). The pH of the inorganic layered compound dispersion (2) was 6.
The pH of the system was adjusted with an ion exchange resin so as to be 10, and a coating liquid (5) was obtained. When the total volume of polyvinyl alcohol, polyacrylic acid and the inorganic layered compound in the coating liquid (5) was 100%, the volume fraction of the inorganic layered compound was 20 vol%.

[Example 1]
The above-mentioned coating is applied to the vapor-deposited surface of an alumina-deposited polyethylene terephthalate film (BARRIALOX VM-PET1011HG; manufactured by Toyo Metallizing Co., Ltd., hereinafter referred to as VM-PET) having a vapor-deposited layer on the base material layer. Using a test coater (manufactured by Yasui Seiki), the working liquid (1) was gravure coated at a coating speed of 3 m / min by a microgravure coating method (number of gravure roll lines 150, #: GM), and 100 ° C. The multilayer structure of 3 layers (base material layer / deposition layer / A layer) including the base material layer was obtained. The thickness of the A layer was 0.2 μm. The results of measuring the oxygen permeability of the multilayer structure are shown in Table 1.

[Example 2]
A multilayer of 3 layers (base material layer / deposition layer / B layer) including the base material layer in the same manner as in Example 1 except that the coating liquid (2) was used instead of the coating liquid (1). A structure was obtained. The thickness of the B layer was 0.2 μm. The results of measuring the oxygen permeability of the multilayer structure are shown in Table 1.

Example 3
A multilayer of 3 layers (base material layer / evaporation layer / C layer) including the base material layer in the same manner as in Example 1, except that the coating liquid (5) was used instead of the coating liquid (1). A structure was obtained. The thickness of the C layer was 0.2 μm. After heat-treating the obtained multilayer structure, the multilayer structure was then subjected to wet heat treatment and further subjected to drying treatment. The results of measuring the oxygen permeability of the multilayer structure are shown in Table 1.

[Comparative Example 1]
A multilayer of 3 layers (base material layer / deposition layer / D layer) including the base material layer in the same manner as in Example 1 except that the coating liquid (3) was used instead of the coating liquid (1). A structure was obtained. The thickness of the D layer was 0.2 μm. The results of measuring the oxygen permeability of the multilayer structure are shown in Table 1.

[Comparative Example 2]
A multilayer of 3 layers (base material layer / evaporation layer / E layer) including the base material layer in the same manner as in Example 1 except that the coating liquid (4) was used instead of the coating liquid (1). A structure was obtained. The thickness of the E layer was 0.2 μm. The results of measuring the oxygen permeability of the multilayer structure are shown in Table 1.

Claims (4)

A base layer, a first layer made of a metal and / or metal oxide formed on at least one surface of the base layer, and a resin and an inorganic layered compound formed adjacent to the first layer. The manufacturing method of the multilayer structure which has the 2nd layer formed from the resin composition containing it, Comprising: The manufacturing method of the multilayer structure which contains the following processes (1) and (2) in order.
(1) A step of forming a first layer on the base material layer by subjecting a metal and / or metal oxide to vapor deposition treatment (2) including a resin, an inorganic layered compound and a liquid medium, and having a pH of 7 to 14 Applying a coating liquid onto the first layer and then removing the liquid medium to form a second layer on the first layer; The method for producing a multilayer structure according to claim 1, wherein the metal in the first layer is aluminum and the metal oxide is aluminum oxide. When the sum of the volume of the inorganic layered compound and the resin in the resin composition forming the second layer is 100%, the proportion of the inorganic layered compound is 5 to 95%, and the proportion of the resin is 5 to 95%. The multilayer structure according to claim 1 or 2. The method for producing a multilayer structure according to claim 1, wherein the resin contained in the resin composition forming the second layer is a resin containing a hydroxyl group.