JP5970830B2 - Inorganic layered compound dispersion and method for producing multilayer structure - Google Patents

Description

  The present invention relates to an inorganic layered compound dispersion and a method for producing a multilayer structure.

  Conventionally, molded articles made of thermoplastic resins such as polypropylene, polyester, and polyamide have been used as packaging materials in the fields of food, cosmetics, agrochemicals, and medical. 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 gas barrier properties, for example, Patent Document 1 is obtained by applying a dispersion containing polyvinyl alcohol, synthetic hectorite, which is an inorganic layered compound, and water on a base film, and then drying. A multilayer film is described.

Japanese Patent Laid-Open No. 03-30944

  However, the film may have insufficient gas barrier properties under high humidity conditions.

  An object of the present invention is to provide an inorganic layered compound dispersion that provides a multilayer structure having excellent gas barrier properties under high humidity conditions. Another object of the present invention is to provide a method for producing a multilayer structure having excellent gas barrier properties under high humidity conditions.

That is, the present invention is an inorganic layered compound dispersion comprising one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids, an inorganic layered compound, and a liquid medium,
In the inorganic layered compound dispersion, the amount of sodium ions contained in the dispersion is 300 μmol or less per 1 g of the inorganic layered compound contained in the dispersion.
In another aspect, the present invention provides, in another aspect, at least one selected from the group consisting of an inorganic layered compound having hydrogen ions between layers, an inorganic layered compound having lithium ions between layers, and an inorganic layered compound having ammonium ions between layers. It is a manufacturing method of the multilayer structure containing the layer containing an inorganic stratiform compound, and a base material layer, Comprising: It is a manufacturing method of the multilayer structure containing the following processes (1) and processes (2).
Step (1): The inorganic layered compound dispersion is applied to the surface of the base material layer to form a coating film, and then dried under a temperature condition of 20 to 150 ° C. to remove the liquid medium from the coating film. Step (2) of manufacturing a preliminary structure including the base material layer and the inorganic layered compound layer (I): The preliminary structure is subjected to heat treatment, and the layer of the inorganic layered compound in the inorganic layered compound layer (I) The process of obtaining a multilayer structure by reducing the distance

  The multilayer structure produced using the inorganic layered compound dispersion of the present invention has excellent gas barrier properties under high humidity conditions.

The inorganic layered compound dispersion of the present invention contains at least one compound selected from the group consisting of oxo acids and metal salts of oxo acids, an inorganic layered compound, and a liquid medium.
As the inorganic layered compound used for obtaining the inorganic layered compound dispersion of the present invention, a clay mineral having swelling property and cleavage property to a liquid medium is preferably used. An inorganic layered compound refers to a product in which unit crystal layers are stacked to form a layered structure. 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.

  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-serpentine group clay minerals. Examples of the three-layer structure type clay mineral (ii) include clay minerals such as talc-pyrophyllite group, smectite group, vermiculite group, mica group, brittle mica group and chlorite group.

Specific examples of the kaolinite-serpentine group include kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, lizardite, amesite, burcherin, cronstedite, nepoite, keriaite, fraponite, blindriaite, etc. Can be mentioned.
Specific examples of the talc-pyrophyllite group include talc, willemsite, kerolite, pimelite, pyrophyllite, ferripyrophyllite and the like.
Specific examples of the smectite group include montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, hectorite, bolcon score, and swinolite.
Specific examples of the vermiculite family include 3 octahedral vermiculite, 2 octahedral vermiculite, and the like.
Specific examples of the mica group include tetrasilicic mica, sodium teniolite, muscovite, phlogopite, biotite, iron mica, eastnite, siderophyllite tetraferri iron mica, scale mica, polylithionite, celadonite. , Iron ceradonite, iron alumina ceradon stone, alumino ceradon stone, mica mica, paragonite, and lipidolite.
Specific examples of the brittle mica group include xanthophyllite, clintnite, bite mica, ananda stone, pearl mica, marguerite, and the like.
Specific examples of the chlorite group include clinochlore, chamosite, penanthite, nimite, bailicroa, donbasite, kukuite, and suedeite.
In addition, these clay minerals treated with organic substances such as ion exchange and improved dispersibility (see Asakura Shoten, “Encyclopedia of Clay”; hereinafter may be referred to as organically modified clay minerals) are also used as inorganic layered compounds. Can be used. As said organic substance which processes a clay mineral, well-known quaternary ammonium salts, such as a dimethyl distearyl ammonium salt and a trimethyl stearyl ammonium salt, a phosphonium salt, an imidazolium salt, etc. can be used.

Among the above clay minerals, the smectite group, vermiculite group and mica group clay minerals, which are the three-layer structure type clay mineral of (ii), are preferred, and the smectite group is particularly preferred. As the smectite group, montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, and hectorite are preferable, and montmorillonite is particularly preferably used from the viewpoint of swellability to a liquid medium and cleavage.
Two or more kinds of inorganic layered compounds may be used.

  The aspect ratio of the inorganic layered compound is preferably 20 to 10,000. When the aspect ratio of the inorganic layered compound is 20 or more, the gas barrier property of the multilayer structure produced using the inorganic layered compound dispersion of the present invention is excellent, which is preferable. When the aspect ratio is 10,000 or less, the inorganic layered compound can be easily swollen and cleaved, and the multilayer structure produced using the inorganic layered compound dispersion of the present invention is excellent in gas barrier properties, which is preferable. The aspect ratio of the inorganic layered compound is a value in an inorganic layered compound dispersion containing the inorganic layered compound and a liquid medium.

  The inorganic layered compound preferably has an average particle size of 10 μm or less. An average particle size of 10 μm or less is preferred because the multilayer structure produced using the inorganic layered compound dispersion of the present invention is excellent in gas barrier properties, transparency and film-forming properties, and is particularly 1 μm for applications where transparency is required. The following is preferable.

  In the present invention, the aspect ratio (Z) of the inorganic layered compound is defined by the formula: Z = L / a. In the formula, 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 the powder X-ray diffraction method (“instrumental analysis”). No. (a) "(1985, published by Kagaku Dojinsha, supervised by Jiro Shiokawa, p. 69).

  The average particle diameter of the inorganic layered compound is a particle diameter (volume-based median diameter) obtained by a diffraction / scattering method in a liquid medium. That is, it can be obtained by calculating the particle size distribution most consistent with the above diffraction / scattering pattern from the diffraction / scattering pattern obtained when light is passed through the dispersion of the inorganic layered compound by Mie scattering theory or the like. it can. Specifically, for example, 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 and calculated. A method is mentioned.

  Specifically, the inorganic layered compound preferably has a swelling value of 5 or more, more preferably a swelling value of 20 or more according to the following swellability test. 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 inorganic layered compound dispersion layer and the supernatant in the graduated cylinder. The larger this numerical value (cleavage value), the higher the cleavage property.

  The liquid medium contained in the inorganic layered compound dispersion of the present invention is not particularly limited, but it is preferable to use a liquid medium that swells and cleaves the inorganic layered compound described below.

  Examples of the liquid medium for swelling and cleaving the inorganic layered compound include water, alcohol, dimethylformamide, dimethyl sulfoxide, and acetone when the inorganic layered compound is a hydrophilic swellable clay mineral. Since it is easy, water, alcohol, and a water-alcohol mixture are preferable. Examples of the alcohol include methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol and the like.

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

In order for the amount of sodium ions contained in the inorganic layered compound dispersion to be 300 μmol or less per 1 g of the inorganic layered compound contained in the dispersion, the inorganic layered compound of the present invention comprises:
One or more inorganic layered compounds selected from the group consisting of an inorganic layered compound having hydrogen ions between layers, an inorganic layered compound having lithium ions between layers, and an inorganic layered compound having ammonium ions between layers are preferable. Inorganic layered compounds usually have cations between layers. As for the inorganic layered compound in which the cation is one or more cations selected from the group consisting of hydrogen ion, lithium ion, and ammonium ion, when a commercially available one is available, it can be used. Since the cation is mainly composed of sodium ions, it is preferable to exchange sodium ions with one or more cations selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions by the method described later.

  Examples of a method for exchanging sodium ions between layers of an inorganic layered compound with one or more cations selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions include, for example, hydrogen ions, lithium ions, and ammonium ions After contacting an ion exchange resin having at least one cation selected from the group with a dispersion containing an inorganic layered compound in which the cation between layers is a sodium ion and a liquid medium, the residue of the ion exchange resin is removed. One or more methods selected from the group consisting of a hydrogen ion, a lithium ion, and an ammonium ion through a semipermeable membrane, a dispersion containing a method, an inorganic layered compound in which an interlayer cation is sodium ion, and a liquid medium Ion exchange using pressure difference or electrodialysis by contacting with liquid containing cation That way, and the like. When a multilayer structure described later is produced using an inorganic layered compound dispersion having at least one cation selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions, the multilayer structure is a gas barrier. It can be made excellent in properties.

  The oxo acid of the present invention is a compound in which a hydroxyl group and an oxo group are bonded to a certain atom, and the hydroxyl group gives an acidic proton. The oxo acids of the present invention can be classified into inorganic oxo acids and organic oxo acids.

  The inorganic oxo acid of the present invention is an inorganic acid, and the central atom may be nonmetal or metal. Specific examples of the inorganic oxo acid having a non-metallic central atom include boric acid, phosphoric acid, sulfuric acid, nitric acid, silicic acid, and carbonic acid. Specific examples of the inorganic oxo acid having a metal central atom include tungstic acid, molybdic acid, chromic acid, vanadic acid, perrhenic acid and permanganic acid. Of these, boric acid, phosphoric acid, sulfuric acid, tungstic acid, molybdic acid, chromic acid, and vanadic acid are preferable, and phosphoric acid is more preferable because of easy handling.

The organic oxo acid of the present invention is an organic acid, usually a carboxylic acid. Examples of the carboxylic acid include monocarboxylic acid, dicarboxylic acid, and tricarboxylic acid.
Examples of the monocarboxylic acid include acetic acid, propionic acid, butyric acid, and the like.
Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, and the like.
Examples of the tricarboxylic acid include citric acid.
Further, it may be a chain carboxylic acid, an aromatic carboxylic acid, or an acid anhydride.
Among these, acetic acid, propionic acid, oxalic acid, and citric acid are preferable because of ease of handling, and acetic acid is more preferable.

  The oxo acid used in the present invention may be a polyacid, and the polyacid may be an isopolyacid or a heteropolyacid.

  In the metal salt of the oxo acid of the present invention, examples of the cation for forming the metal salt include ammonium ion, alkali metal ion, 1,2,3 or quaternary alkyl ammonium ion, phosphonium ion and sulfonium ion. Can be mentioned. Among these, when the inorganic layered compound dispersion of the present invention is produced by ion exchange according to the above-described method, alkali metal ions or ammonium ions are preferable from the viewpoint of ease of ion exchange, and sodium ions, lithium ions or ammonium ions are preferable. It is more preferably an ion, and further preferably a sodium ion.

  The oxo acid may be used alone or in combination of two or more. Similarly, the metal salt of oxo acid may be used alone or in combination of two or more. Moreover, you may use combining oxo acid and the metal salt of oxo acid.

  As the liquid medium of the present invention, it is preferable to use a liquid medium that swells and cleaves the aforementioned inorganic layered compound. Of these, water, alcohols, and water-alcohol mixtures are preferred from the viewpoint of the solubility of one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids.

The amount of sodium ions in the inorganic layered compound dispersion of the present invention is 300 μmol or less per 1 g of the inorganic layered compound contained in the dispersion. More preferably, it is 200 micromol or less, More preferably, it is 100 micromol or less.
The total amount of lithium ions, hydrogen ions, and ammonium ions in the inorganic layered compound dispersion of the present invention is preferably 500 μmol or more, and 600 μmol or more per 1 g of the inorganic layered compound in the dispersion. Is more preferably 700 μmol or more. In addition, when the total of lithium ions, hydrogen ions, and ammonium ions is 100%, the amount of hydrogen ions is more preferably 50% or more.
More preferably, the sodium ion concentration satisfies the above-described conditions, and the total concentration of lithium ions, hydrogen ions, and ammonium ions satisfies the above-described conditions.

  When a multilayer structure described later is manufactured using an inorganic layered compound dispersion that satisfies the requirements for sodium ion concentration, lithium ion concentration, hydrogen ion concentration, and ammonium ion concentration, the water resistance and gas barrier properties are excellent. A multilayer structure.

  The preparation method of each cation concentration can be performed using the above-mentioned ion exchange method.

  As for the qualitative and quantitative method of the cation in the inorganic layered compound dispersion, when the cation is a metal ion such as sodium ion or lithium ion, measurement is performed using an inductively coupled plasma emission spectrometer. Metal concentrations such as sodium concentration and lithium concentration measured using the inductively coupled plasma optical emission spectrometer are defined as sodium ion concentration and lithium ion concentration, respectively. Further, when the cation is a non-metallic ion such as an ammonium ion, it can be determined by capillary electrophoresis. Moreover, about hydrogen ion, it can obtain | require by the difference of the cation concentration in the inorganic layered compound before ion exchange, and the cation concentration in the inorganic layered compound after ion exchange. When an inorganic layered compound dispersion is available, each ion concentration can be measured using a sample obtained by removing the liquid medium from the inorganic layered compound dispersion. If the inorganic layered compound dispersion is not available, measure the ion concentration of the entire multilayer structure described later, and subtract the cation concentration contained in the layers other than the inorganic layered compound layer to obtain the ion concentration. Can be sought.

When the total weight of the inorganic layered compound and one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids contained in the inorganic layered compound dispersion of the present invention is 100% by weight, the oxoacid And the ratio of one or more compounds selected from the group consisting of metal salts of oxo acids is preferably 0.01 to 10% by weight, more preferably 0.01 to 5% by weight, More preferably, it is ˜2% by weight. When the ratio of one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids is within the above range, ion exchange is performed by the method described above to produce the inorganic layered compound dispersion of the present invention. When it becomes easy to reduce sodium ions and a multilayer structure described later is produced using the inorganic layered compound dispersion of the present invention, the multilayer structure can be excellent in gas barrier properties.
When the weight of the inorganic layered compound dispersion is 100% by weight, the ratio of the total weight of the inorganic layered compound and one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids is 0 0.1 to 20% by weight is preferable, 1 to 15% by weight is more preferable, and 3 to 10% by weight is even more preferable. By setting the ratio of the total weight of at least one compound selected from the group consisting of oxo acid and metal salt of oxo acid and the inorganic layered compound within the above range, the inorganic layered compound layer (I) in the multilayer structure described later It is excellent in film forming property when forming.
When the weight of the inorganic layered compound dispersion is 100% by weight, the proportion of the inorganic layered compound is preferably 0.1 to 20% by weight, more preferably 1 to 15% by weight, More preferably, it is 10% by weight.

Examples of the method for producing the inorganic layered compound dispersion include a method of mixing in the following order.
In the case of using an inorganic layered compound in which the cation between layers is sodium ion, the following methods (i) to (vi) may be mentioned.
(I) A dispersion (1) in which a liquid medium and an inorganic stratiform compound are mixed is prepared, and sodium ions that the inorganic stratiform compound in the dispersion (1) has between the layers are hydrogen ions, lithium ions, and ammonium ions. A method of preparing a dispersion (1 ′) ion-exchanged with one or more cations selected from the group consisting of, and then mixing one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids .
(Ii) The dispersion (1) is mixed with one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids to prepare the dispersion (2), and then the dispersion (2) A method of ion-exchanging sodium ions between layers of an inorganic layered compound with at least one cation selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions.
(Iii) One or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids and an inorganic layered compound are mixed in advance to prepare a mixture, and then the mixture and the liquid medium are further mixed and dispersed. A method of ion-exchanging sodium ions between the layers of the inorganic layered compound in dispersion (3) into at least one cation selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions. .
(Iv) One or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids are dissolved in a liquid medium, and then mixed with an inorganic layered compound to prepare a dispersion (4). 4) A method in which the sodium ion of the inorganic layered compound in the layer is ion-exchanged with at least one cation selected from the group consisting of hydrogen ion, lithium ion, and ammonium ion.
(V) The dispersion liquid (1) was mixed with a liquid obtained by dissolving one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids in a liquid medium to prepare a dispersion liquid (5). Then, the method of ion-exchanging the sodium ion which the inorganic stratiform compound in a dispersion liquid (5) has between layers to 1 or more types of cations chosen from the group which consists of a hydrogen ion, a lithium ion, and an ammonium ion.
(Vi) Dispersion liquid obtained by ion-exchange of sodium ions between the layers of the inorganic layered compound in dispersion liquid (1) with at least one cation selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions ( 1 ') and a solution prepared by dissolving one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids in a liquid medium.

When the cation between the layers of the inorganic layered compound used for the production of the inorganic layered compound dispersion is an inorganic layered compound having one or more cations selected from the group consisting of hydrogen ions, lithium ions, and ammonium ions. The following methods (vii) to (x) are mentioned.
(Vii) A method of mixing one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids in a dispersion (6) in which a liquid medium and an inorganic layered compound are mixed.
(Viii) A method in which one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids and an inorganic layered compound are mixed in advance to prepare a mixture, and then the mixture and the liquid medium are further mixed .
(Ix) A method of mixing an inorganic layered compound after mixing one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids with a liquid medium.
(X) A liquid obtained by mixing a liquid (3) prepared by mixing a liquid medium and an inorganic layered compound, one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids, and the liquid medium And how to mix.

  From the viewpoint of dispersibility of the inorganic layered compound, the method (iv) or (ix) is preferably used.

When preparing a liquid containing an inorganic layered compound such as the inorganic layered compound dispersion of the present invention, the above dispersions (1) to (6), or the dispersion (1 ′), the viewpoint of dispersibility of the inorganic layered compound Therefore, it is preferable to perform high-pressure dispersion treatment using a high-pressure dispersion apparatus. 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. High-pressure dispersion treatment means that a liquid containing an inorganic layered compound is passed through a plurality of thin tubes at a high speed, and then combined to cause the liquids containing the inorganic layered compound to collide with each other or the liquid containing the inorganic layered compound and the inner wall of the thin tube. Thus, a high shear and / or high pressure is applied to the liquid containing the inorganic layered compound. In the high-pressure dispersion treatment, it is preferable that the liquid containing the inorganic stratiform compound is passed through a thin 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. Further, when the liquid containing the inorganic layered compound passes through the narrow tube, the maximum arrival speed of the liquid containing the inorganic layered compound is preferably 100 m / second or more, and the heat transfer rate due to pressure loss is 100 kcal / hour or more. It is preferable.
The inorganic layered compound dispersion of the present invention may contain a resin as a component other than one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids, inorganic layered compounds, and liquid media. When the inorganic layered compound dispersion of the present invention contains a resin, the layer containing the inorganic layered compound of the multilayer structure obtained by the production method described later has flexibility.

  Examples of the resin include polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride, polyacrylonitrile, polysaccharides, polyacrylic acid and esters thereof, polymethacrylic acid and esters thereof, An amide resin, an imide resin, an ester resin, a resin having two or more kinds of functional groups in one molecule, and a urethane resin are exemplified, and a resin that is dissolved or dispersed in water, alcohol, or a water-alcohol mixture is preferable.

Polyvinyl alcohol is a polymer having a monomer unit based on vinyl alcohol as a main component. Examples of such polyvinyl alcohol include a polymer obtained by hydrolyzing the ester portion of a vinyl ester compound polymer and a polymer obtained by hydrolyzing the ether portion of a vinyl ether compound polymer. Examples of the vinyl ester compound include vinyl acetate, vinyl trifluoroacetate, vinyl formate, and vinyl pivalate. Examples of the vinyl ether compound include t-butyl vinyl ether, trimethylsilyl vinyl ether and the like (for details of “polyvinyl alcohol”, for example, edited by Poval Society, “World of PVA”, 1992, Kobunshi Publishing Co., Ltd. Nagano et al., “Poval”, 1981, can be referred to Kobunshi Publishing Co., Ltd.). The degree of hydrolysis (saponification) of the vinyl ester compound polymer and the vinyl ether compound polymer is preferably 70 mol% or more, more preferably 85 mol% or more, and 98% mol or more of a so-called completely saponified product. Further preferred. For example, when the degree of hydrolysis (saponification) of the vinyl acetate polymer is less than 100 mol%, the hydrolyzed polymer is a polymer having monomer units based on vinyl acetate and monomer units based on vinyl alcohol. It is.
The degree of polymerization is more preferably from 100 to 5000, and more preferably from 200 to 3000.

Also, as the polyvinyl alcohol, so-called polyvinyl alcohol derivatives having a functional group other than a hydroxyl group can be used. Examples of the functional group other than a hydroxyl group include an amino group, a thiol group, a carboxyl group, a sulfone group, a phosphate group, a carboxylate group, and a sulfone group. Examples thereof include an acid ion group, a phosphate ion group, an ammonium group, a phosphonium group, a silyl group, a siloxane group, an alkyl group, an allyl group, a fluoroalkyl group, an alkoxy group, a carbonyl group, and a halogen group. A part of hydroxyl groups in PVA may be replaced with one or more of these functional groups.

  Polysaccharides are biopolymers synthesized in biological systems by polycondensation of various monosaccharides, and here include those chemically modified based on them. For example, cellulose and cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, amylose, amylopectin, pullulan, curdlan, xanthan, chitin, chitosan, and the like can be given.

  An imide resin is a resin having an imide bond in a repeating unit in the molecule, and refers to an aromatic polyimide in which an aromatic compound is directly linked by an imide bond. Specifically, polyamic acid is dehydrated and cyclized. The resulting resin.

  The amide resin is a resin having an amide bond in a repeating unit in the molecule, and examples thereof include an aliphatic polyamide having an aliphatic skeleton or an aromatic polyamide having an aromatic skeleton. Examples of the aliphatic polyamide include a polycondensation reaction product of ε-caprolactam and a copolycondensation product of hexamethylenediamine and adipic acid. Examples of the aromatic polyamide include a copolycondensation product of p-phenylenediamine and terephthalic acid chloride, a copolycondensation product of m-phenylenediamine and isophthalic acid chloride, and the like.

As a resin containing two or more functional groups in one molecule, one molecule of two or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a sulfonic acid group, a carboxylate group, and an ammonium group is used. A resin contained therein is preferable. Moreover, it is preferable that the two or more types of functional groups are functional groups capable of covalent bonding or ionic bonding. Specifically, vinyl alcohol-acrylic acid copolymer, vinyl alcohol-methacrylic acid copolymer, vinyl alcohol-vinylamine copolymer, acrylic acid-vinylamine copolymer, methacrylic acid-vinylamine copolymer, etc. Among the copolymers and the polyvinyl alcohol derivatives or polysaccharides, there may be mentioned resins having a functional group selected from the group consisting of carboxyl group, amino group, sulfonic acid group, carboxylate group, and ammonium group.
From the viewpoint of gas barrier properties of a film that can be easily dissolved in an aqueous liquid medium and that is easy to handle and that is obtained using the dispersion obtained by the production method of the present invention, It is preferable that it is resin containing a carboxyl group, and it is preferable that they are a vinyl alcohol-acrylic acid copolymer and a vinyl alcohol-methacrylic acid copolymer.

Two or more kinds of the above resins may be used in combination. When two or more kinds of resins are used in combination, each resin is preferably a resin containing functional groups different from each other, and the functional group contained in each resin is a functional group capable of covalent bonding or ionic bonding. It is preferable that It is preferable to use a resin containing a functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a sulfonic acid group, a carboxylate group, and an ammonium group. Specifically, combinations of two or more of polyvinyl alcohol, polysaccharides, polyacrylic acid, polymethacrylic acid, polyacrylic acid partial neutralized product, polymethacrylic acid partial neutralized product, polyvinylamine, and the like can be mentioned. It is done.
From the viewpoint of gas barrier properties of a film that can be easily dissolved in an aqueous liquid medium, is easy to handle, and is obtained using the dispersion obtained by the production method of the present invention, It is preferable to use a resin containing a carboxyl group in combination. In this case, polyvinyl alcohol is preferably used as the resin containing a hydroxyl group, and polyacrylic acid, polymethacrylic acid, a polyacrylic acid partial neutralized product, or a polymethacrylic acid partial neutralized product is preferably used as the resin containing a carboxyl group.

  The resin containing a carboxyl group is preferably at least one resin selected from polyacrylic acid, polymethacrylic acid, a polyacrylic acid partial neutralized product, and a polymethacrylic acid partial neutralized product. A copolymer of acrylic acid and methacrylic acid can also be used. The average molecular weight of the resin containing a carboxyl group is preferably in the range of 2,000 to 1,000,000, more preferably 100,000 to 1,000,000.

The partially neutralized polyacrylic acid or the partially neutralized polymethacrylic acid can be usually obtained by adding an alkali to an aqueous solution of polyacrylic acid or polymethacrylic acid. By adjusting the amount ratio of polyacrylic acid or polymethacrylic acid and alkali, a desired degree of neutralization can be achieved. The neutralized polyacrylic acid and the partially neutralized polymethacrylic acid preferably have a neutralization degree of 0.1% to 20% calculated from the following formula from the viewpoint of gas barrier properties and transparency.
Degree of neutralization = (A / B) × 100
A: Total number of moles of neutralized carboxyl groups contained in 1 g of polyacrylic acid or polymethacrylic acid B: Total number of moles of carboxyl groups before neutralization contained in 1 g of polyacrylic acid or polymethacrylic acid

  When a resin containing a hydroxyl group and a carboxyl group is used in one molecule, or when a resin containing a hydroxyl group and a resin containing a carboxyl group are used in combination, a resin containing a hydroxyl group and a resin containing a carboxyl group is used in one molecule. The molar ratio of the hydroxyl group to the carboxyl group in the mixture is preferably hydroxyl group: carboxyl group = 30: 70 to 95: 5, more preferably 70:30 to 95: 5. In addition, in order to make the film obtained by using the dispersion obtained by the production method of the present invention excellent in gas barrier properties particularly under high humidity conditions, a resin containing a hydroxyl group and a carboxyl group in one molecule, Or it is preferable that the total weight of the hydroxyl group and carboxyl group contained in the mixture of resin containing a hydroxyl group and resin containing a carboxyl group is 30 to 60 weight%, More preferably, it is 35 to 55 weight%. The total weight of the hydroxyl group and the carboxyl group is a value when the weight of the resin containing the hydroxyl group and the carboxyl group in one molecule or the weight of the mixture of the resin containing the hydroxyl group and the resin containing the carboxyl group is 100% by weight. It is.

  When a resin containing a hydroxyl group and a carboxyl group in one molecule is used, or when a resin containing a hydroxyl group and a resin containing a carboxyl group are used in combination, the molar ratio of the hydroxyl group to the carboxyl group is determined by a known NMR method or IR method. Etc. can be obtained. For example, in the case of the IR method, a calibration curve can be obtained and calculated using a sample having a known molar ratio of hydroxyl group to carboxyl group. Moreover, when using polyvinyl alcohol, which is a completely saponified product, and acrylic acid homopolymer and / or methacrylic acid homopolymer, the number of moles of hydroxyl groups and carboxyl groups can be obtained from the weight in advance to calculate the molar ratio. it can. About the total weight measurement of a hydroxyl group and a carboxyl group, it can obtain | require by well-known NMR method, IR method, etc. similarly to molar ratio. For example, in the case of the IR method, a calibration curve can be obtained and calculated for a polyol polymer having a known number of polyol units and a polycarboxylic acid polymer having a known number of polycarboxylic acid units. Moreover, when using polyvinyl alcohol which is a completely saponified product, and acrylic acid homopolymer and / or methacrylic acid homopolymer, the weight of hydroxyl group and carboxyl group is obtained from the weight in advance, and this total amount can be used. .

  When a resin containing a hydroxyl group and a carboxyl group in one molecule is used, or when a resin containing a hydroxyl group and a resin containing a carboxyl group are used in combination, the film obtained using the dispersion obtained by the production method of the present invention From the viewpoint of water resistance, it is preferable to contain an alkali metal ion. Examples of alkali metal ions include sodium ions, lithium ions, and potassium ions. When the weight of the resin used is 100%, it is preferably 2000 to 50000 ppm, more preferably 2000 to 20000 ppm.

  The alkali metal ion is derived from an alkali metal ion donating compound. That is, when a resin containing a hydroxyl group and a carboxyl group in one molecule is used, or when a resin containing a hydroxyl group and a resin containing a carboxyl group are used in combination, an alkali metal ion donating compound is preferably contained. Examples of the alkali metal ion donating compound include sodium hydroxide, sodium hypophosphite, lithium hydroxide, potassium hydroxide, alkali metal salts of the above oxo acids, and the like. When montmorillonite is used as the inorganic layered compound, montmorillonite acts as an alkali metal ion donating compound because sodium ions are contained between the montmorillonite layers. Therefore, it is particularly preferable to use montmorillonite as the inorganic layered compound. Two or more kinds of alkali metal ion donor compounds may be used in combination.

  When the inorganic layered compound dispersion of the present invention contains the resin, the total volume of the inorganic layered compound and the resin is 100 from the viewpoint of gas barrier properties of the multilayer structure obtained using the dispersion obtained in the present invention. When setting it as volume%, it is preferable that the ratio of resin is 1-20 volume%, It is more preferable that it is 1-10 volume%, It is further more preferable that it is 1-5 volume%. Moreover, from the point of the softness | flexibility of the inorganic layered compound layer in this multilayer structure, when the total volume of the said inorganic layered compound and the said resin shall be 100 volume%, the ratio of resin is 50-90 volume%. It is preferably 60 to 80% by volume, more preferably 70 to 80% by volume.

  A surfactant may be added to the inorganic layered compound dispersion. By applying an inorganic layered compound dispersion containing a surfactant to form an inorganic layered compound layer described later, the adhesion between the layer and the adjacent layer can be improved. The content of the surfactant is usually 0.001 to 5% by weight in 100% by weight of the inorganic layered compound dispersion. When the addition amount of the surfactant is 0.001% by weight or more, the adhesion is easily improved, and when the addition amount of the surfactant is 5% by weight or less, the gas barrier property is favorable, which is preferable.

  As the surfactant, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant, a nonionic surfactant, or the like 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) ) Or a fluorine-type nonionic surfactant (fluorine-based nonionic surfactant) such as a perfluoroalkylethylene oxide compound is preferable from the viewpoint of improving adhesion.

A layer containing one or more inorganic layered compounds selected from the group consisting of an inorganic layered compound having hydrogen ions between layers, an inorganic layered compound having lithium ions between layers, and an inorganic layered compound having ammonium ions between layers; The method for producing a multilayer structure including a base material layer includes the following steps (1) and (2).
(1) The inorganic layered compound dispersion is applied to the surface of the base material layer to form a coating film, and then dried under a temperature condition of 20 to 150 ° C. to remove the liquid medium from the coating film. (2) A step of producing a preliminary structure including the base material layer and the inorganic layered compound layer (I) (2) The preliminary structure is heat-treated to reduce the interlayer distance of the inorganic layered compound in the inorganic layered compound layer (I). And obtaining a multilayer structure

The multilayer structure obtained by the production method of the present invention has a base material layer. Examples of the material constituting the base material layer include metals, resins, wood, ceramics, and glass. Examples of the form of the base material layer include paper, cloth, nonwoven fabric, and film.
Examples of the metal include copper, iron, silver, aluminum and the like, and alloys thereof are also included.
Examples of ceramics include alumina, silica, zirconia, and titanium oxide.
As the resin, a thermoplastic resin, a thermosetting resin, a photocurable resin, or the like can be used.
Thermoplastic resins include olefin resins, ethylene copolymers, ester resins, amide resins, polyarylate, acrylic resins, polystyrene, styrene resins, hydrophobic cellulose resins, chlorine resins, fluorine resins. , Hydrogen bonding resin, carbonate resin, sulfone resin, ether sulfone resin, ether ether ketone resin, phenylene oxide resin, methylene oxide resin, imide resin and the like.
Examples of the olefin resin include polyethylene, ethylene-α-olefin copolymer, polypropylene, polybutene-1, poly-4-methylpentene-1.
Examples of the ethylene copolymer include an ethylene-vinyl acetate copolymer or a saponified product thereof, an ethylene-α / β unsaturated carboxylic acid ester copolymer, an ethylene-α / β unsaturated carboxylic acid copolymer, and the like. .
Examples of the ester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.
Examples of amide resins include nylon-6 (Ny-6), nylon-6,6, metaxylenediamine-adipic acid condensation polymer, polymethylmethacrylamide, polymetaxylylene adipamide (MXD6-Ny), and the like. It is done.
Examples of the acrylic resin include polymethyl methacrylate.
Examples of the styrenic resin include AS resin and ABS resin.
Examples of the hydrophobic cellulose resin include cellulose triacetate and cellulose diacetate.
Examples of the chlorine-based resin include polyvinyl chloride and polyvinylidene chloride.
Examples of the fluorine-based resin include polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and the like.
Examples of the hydrogen bonding resin include polyvinyl alcohol, ethylene-vinyl alcohol copolymer (EVOH), cellulose derivatives, and the like. Among these, the weight fraction of hydroxyl groups per unit weight of the resin satisfies a ratio of 20 to 60%. Polymers are preferred.
Examples of the thermosetting resin include a phenol resin, a melamine resin, a urea resin, an ethyleneimine resin, and a resin obtained by reacting a thermoreactive composition described later.
Examples of the photocurable resin include an epoxy resin and an acrylic resin obtained by polymerizing an epoxy compound or an acrylic compound using a photopolymerization initiator.

When the multilayer structure obtained by the production method of 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.
Further, the base material layer may be a multilayer film such as Ny-6 layer / MXD6-Ny layer / Ny-6 layer or polypropylene layer / ethylene-vinyl alcohol copolymer layer / polypropylene layer, aluminum, alumina, A film on which silica is deposited may be used.

  In laminating the substrate layer with other layers, surface treatment such as corona treatment, ozone treatment, electron beam treatment, ion treatment, flame treatment using gas such as silane, atmospheric pressure or reduced pressure plasma treatment, etc. It may be given in advance. An anchor coat layer may be provided on the surface of the base material layer. The anchor coat layer can be formed using an ethyleneimine-based, two-component curable urethane-based anchor coat agent or the like. Moreover, you may perform the said surface treatment also about an inorganic layered compound layer (I), the below-mentioned heat-reactive composition layer, and a resin layer.

  As a method for forming a coating film by coating an inorganic layered compound dispersion on the surface of a base material layer, a gravure method such as a direct gravure method or a reverse gravure method, a two-roll beat coat method, a bottom feed three-reverse coat method Roll coating methods such as doctor coating, die coating, bar coating, dipping, spray coating, and spin coating. When the multilayer structure obtained by the production method of the present invention is a film, it is preferable to employ a gravure method, a spin coating method or a die coating method since a layer having a uniform thickness can be provided. In addition, a coating film may be formed in a part of base material layer surface, and may be formed in the whole surface. The same method can also be applied when an anchor coat layer or a heat-reactive composition layer described later is provided.

The coating film is dried under a temperature condition of 20 to 150 ° C., the liquid medium is removed from the coating film, and the inorganic layered compound layer (I) is formed. The temperature condition is preferably 30 to 140 ° C, more preferably 40 to 130 ° C, and still more preferably 50 to 120 ° C. The drying time is usually 1 second to 24 hours. The water vapor concentration during the heat treatment is preferably 0 to 40 g / m ³ . The heat source used for the 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. What is necessary is just to dry the drying process in a process (1) to such an extent that a bubble etc. do not generate | occur | produce in an inorganic layered compound layer (I) in the heat processing in the below-mentioned process (2).

Step (2) in the method for producing a multilayer structure of the present invention is a step of heating the preliminary structure to reduce the interlayer distance of the inorganic layered compound in the inorganic layered compound layer (I) to obtain a multilayer structure. .
As conditions for heat-treating a preliminary structure in a process (2), it is preferable that it is 160-350 degreeC, It is more preferable that it is 170-320 degreeC, It is further more preferable that it is 200-300 degreeC. The heat treatment is preferably carried out in an atmosphere having a water vapor concentration of less than 50 g / m ³ . The time for the heat treatment is usually 1 second to 24 hours. The heat source used for the heat treatment is not particularly limited, and the same method as the drying treatment in step (1) can be applied.
As described above, after the drying treatment is performed under the above-described conditions, the inorganic layered compound layer (I) is free of bubbles and the like, and the liquid medium can be almost completely removed by performing the heat treatment. An inorganic layered compound having a narrow distance can be obtained.

The multilayer structure obtained by the production method of the present invention may have a layer other than the inorganic layered compound layer and the base material layer. Moreover, you may have multiple layers of the same composition as an inorganic layered compound layer, respectively. As the configuration of the multilayer structure obtained by the production method of the present invention, for example, base layer / inorganic layered compound layer / additional layer A (configuration 1),
Base layer / inorganic layered compound layer / additional layer B / additional layer C (configuration 2),
Base layer / inorganic layered compound layer / additional layer D / additional layer E / additional layer F (configuration 3),
Base material layer / additional layer G / inorganic layered compound layer (configuration 4),
Base layer / additional layer H / inorganic layered compound layer / additional layer I (configuration 5),
Base layer / additional layer J / inorganic layered compound layer / additional layer K / additional layer L (configuration 6),
Is mentioned.
Here, the additional layers C, E, and L may have the same composition as the inorganic layered compound layer, and the additional layers A, B, D, F, G, H, I, J, and K are, for example, thermal reactions described later. The resin layer which a reactive composition reacts may be sufficient.
The heat-reactive composition is a relatively low molecular weight substance that is liquid, semi-solid or solid at room temperature and exhibits fluidity at room temperature or under heating. It is a composition capable of forming a network-like three-dimensional structure while causing a reaction to increase the molecular weight. The heat-reactive composition used in the present invention is preferably soluble in a solvent before the heat treatment described above, and the resin layer formed by the heat treatment is insoluble in the solvent.

Examples of the thermally reactive composition include a composition containing two or more types of monomers that react with each other, a composition containing a monomer that is polymerized by heating to form a polymer, and a polymerization initiator. Examples of the composition containing two or more kinds of monomers that react with each other include a composition containing a monomer containing a hydroxyl group and a monomer containing a carboxyl group. Examples of the monomer that polymerizes by heating to form a polymer include epoxy compounds, (meth) acryloyl compounds, allyl compounds, and vinyl compounds.
The heat-reactive composition is preferably a composition containing an epoxy compound and a polymerization initiator, or a composition containing a monomer containing a hydroxyl group and a monomer containing a carboxyl group.

  The epoxy compound refers to a compound having at least one epoxy group. The number of epoxy groups in the epoxy compound is preferably 1 or more per molecule, and more preferably 2 or more per molecule. Here, the number of epoxy groups per molecule is obtained by dividing the total number of epoxy groups in the epoxy compound by the total number of molecules in the epoxy compound.

  As the epoxy compound, a compound having a known epoxy group can be used, for example, a bisphenol type epoxy compound, a novolac type epoxy compound, a glycidyl ester type epoxy compound, a glycidyl amine type epoxy compound, a fluorene type epoxy. Examples of the compound are epoxy compounds having an aromatic ring in the molecule. An epoxy compound having a siloxane bond in the molecule such as a silsesquioxane unit can also be used. The heat-reactive composition may contain two or more types of epoxy compounds.

  Examples of polymerization initiators for epoxy compounds include amines such as bis (4-aminocyclohexyl), methanediaminodiphenylsulfone, 1,5-azabicyclo- (4,3,0) -nonene-7, and salts thereof. Acid anhydrides such as phthalic anhydride and dodecenyl succinic anhydride; polyhydric phenols such as bisphenol F and phenol novolak; imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole BF3 complex compounds of amines as described above; Bronsted acid salts such as aromatic sulfonium salts, iodonium salts and phosphonium salts; organic acid hydrazides such as adipic acid dihydrazide and phthalic acid dihydrazide; dicyandiamides; adipic acid and sebacic acid , Terephthalic acid, trimellitic acid and carboxy Polycarboxylic acids such as group-containing polyester. Ionic thermal latent cations such as benzylsulfonium salt, benzylammonium salt, benzylpyridinium salt, and benzylphosphonium salt with antimony hexafluoride, phosphorous hexafluoride, and boron fluoride as counter anions from the viewpoint of reaction rate Polymerization initiator: It is preferable to use a nonionic thermal latent cationic polymerization initiator such as N-benzylphthalimide and aromatic sulfonate ester. The polymerization initiator preferably has a polyimide skeleton in the molecule. The polyimide skeleton here refers to a structure in which aromatic compounds are directly linked by an imide bond. Two or more kinds of polymerization initiators may be used.

Examples of the composition containing a monomer containing a hydroxyl group and a monomer containing a carboxyl group include a composition containing an aromatic alcohol and an aromatic carboxylic acid.
Specifically, a combination of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol, a plurality of types of aromatic hydroxycarboxylic acids, a combination of an aromatic dicarboxylic acid and an aromatic diol, Can be used in which a part of the aromatic hydroxycarboxylic acid is replaced with an aromatic aminocarboxylic acid, and a part of the aromatic diol is replaced with an aromatic amine and / or an aromatic diamine having a phenolic hydroxyl group. (1) aromatic hydroxycarboxylic acid, (2) aromatic dicarboxylic acid and (3) aromatic diamine, aromatic amine having a hydroxyl group or aromatic amino acid, It is preferable to contain.

Examples of the aromatic hydroxycarboxylic acid represented by the above (1) include p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4′-biphenylcarboxylic acid, and the like. It preferably contains hydroxy-6-naphthoic acid. Two or more of these may be used.
Examples of the aromatic dicarboxylic acid represented by the above (2) include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like, and preferably includes isophthalic acid. Two or more of these may be used.
Examples of the aromatic diamine represented by the above (3), the aromatic amine having a hydroxyl group or the aromatic amino acid include 3-aminophenol, 4-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, An aminobenzoic acid etc. are mentioned, However, It is preferable that 4-aminophenol is included. Two or more of these may be used.

  In the above (1) to (3), an ester-forming derivative may be used. Examples of ester-forming derivatives of carboxylic acids include those in which the carboxyl group is a derivative having a high reaction activity such as an acid chloride or an acid anhydride that promotes the reaction to form a polyester. And those that form esters with alcohols, ethylene glycol, or the like that form polyesters by transesterification. Examples of the ester-forming derivative of a phenolic hydroxyl group include those in which a phenolic hydroxyl group forms an ester with a carboxylic acid so that a polyester is produced by a transesterification reaction. Examples of the ester-forming derivative of an amino group include those in which an amino group forms an ester with a carboxylic acid so that a polyester is produced by a transesterification reaction.

When the heat-reactive composition is a composition containing an aromatic alcohol and an aromatic carboxylic acid, use a prepolymerized part thereof in a range soluble in the aprotic solvent shown below. It doesn't matter.
Examples of the aprotic solvent include halogen solvents such as 1-chlorobutane, chlorobenzene, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, 1,1,2,2-tetrachloroethane, diethyl ether, tetrahydrofuran , Ether solvents such as 1,4-dioxane, ketone solvents such as acetone and cyclohexanone, ester solvents such as ethyl acetate, lactone solvents such as γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, triethylamine Amide solvents such as pyridine, amine solvents such as acetonitrile and succinonitrile, amide solvents such as N, N′-dimethylformamide, N, N′-dimethylacetamide, tetramethylurea and N-methylpyrrolidone Nitro solvents such as nitromethane and nitrobenzene, sulfide solvents such as dimethyl sulfoxide and sulfolane, and phosphoric acid solvents such as hexamethylphosphoric acid amide and tri-n-butylphosphoric acid.

  As a method for forming the heat-reactive composition layer, a coating solution in which the heat-reactive composition is dissolved or dispersed in a liquid medium is applied onto the substrate layer or the inorganic layered compound layer (I) to form a coating film. And a method of removing the liquid medium from the coating film. Since it is preferable that the heat-reactive composition layer undergoes the reaction in the heat treatment in the step (2), when removing the liquid medium, the reaction of the monomer contained in the heat-reactive composition layer should be suppressed as much as possible. It is preferable to dry at a low temperature. The temperature is usually 20 to 150 ° C., and the drying time is usually 0.1 seconds to 1 hour.

  The liquid medium contained in the coating liquid used for forming the heat-reactive composition layer is not particularly limited as long as it is a liquid medium in which the heat-reactive composition dissolves or disperses. Examples thereof include a liquid medium that swells and cleaves, and the above aprotic solvent. A surfactant may be added to the coating solution from the viewpoint of improving adhesion. The content of the surfactant is usually 0.001 to 5% by weight in 100% by weight of the coating solution.

As a method for forming the heat-reactive composition layer on the base material layer or the inorganic layered compound layer (I), the same method as the method for forming the inorganic layered compound layer (I) on the base material layer described above is used. it can.
In the step (2) in the method for producing a multilayer structure of the present invention, by performing heat treatment, the interlayer distance of the inorganic layered compound in the inorganic layered compound layer (I) is narrowed, and at the same time, in the thermally reactive composition layer It is preferable to proceed with the reaction of the components to form the resin layer. Thereby, the multilayer structure excellent in the adhesiveness of an inorganic layered compound layer and a resin layer can be obtained.

When the resin formed by reacting the components in the thermally reactive composition layer is a thermal reaction product of a composition containing an aromatic alcohol and an aromatic carboxylic acid, a structural unit derived from an aromatic diamine, a hydroxyl group It is preferable to contain 10 to 35 mol% of a structural unit derived from an aromatic amine, a structural unit derived from an aromatic amino acid, or two or more of the above structural units. The resin includes structural units represented by the following formulas (1) to (3) as structural units, the structural unit represented by the formula (1) is 30 to 80 mol%, and the structure represented by the formula (2). The unit is preferably 35 to 10 mol%, and the structural unit represented by the formula (3) is preferably 35 to 10 mol%.
Formula (1) -O-Ar1-CO-
Formula (2) -CO-Ar2-CO-
Formula (3) -X-Ar3-Y-
Here, Ar1 represents 1,4-phenylene, 2,6-naphthalene, or 4,4′-biphenylene. Ar2 represents 1,4-phenylene, 1,3-phenylene, or 2,6-naphthalene. Ar3 represents 1,4-phenylene or 1,3-phenylene. X represents —NH—, and Y represents —O— or —NH—.

  The thickness of each layer which comprises the multilayer structure obtained with the manufacturing method of this invention is not specifically limited. The thickness of the inorganic layered compound layer and the resin layer is usually 0.01 μm to 50 μm when the multilayer structure obtained in the present invention is used as a gas barrier material. From the viewpoint of bending resistance, the thickness of the inorganic layered compound layer is preferably thinner than the thickness of the resin layer. The thickness of the additional layer is usually 0.01 μm to 50 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.

Moreover, when the multilayer structure obtained by the production method of the present invention has a resin containing a hydroxyl group and a carboxyl group in one molecule, or a resin containing a hydroxyl group and a resin containing a carboxyl group, after the heat treatment, It is preferable to perform a wet heat treatment. 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 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. Moreover, in the case of the process hold | maintained in 80 degreeC or more water, it is preferable that the temperature of water is 100 degreeC or more, and the inside of the range of 120-200 degreeC is more preferable.

  Each layer which comprises the multilayer structure of this invention may contain various additives, such as a ultraviolet absorber, a coloring agent, and antioxidant, as needed.

The multilayer structure obtained by the production method of the present invention includes an optical component member such as a tire or screw, a substrate for liquid crystal display, a substrate for flexible display such as an organic EL substrate or a sealing material, a silicon solar cell or a dye-sensitized solar. Examples include substrates such as batteries, electronic component members such as sealing materials, and vacuum heat insulating material panels.
When the multilayer structure is used, for example, as a display substrate, it can meet the demands for weight reduction and enlargement compared to a glass substrate that is heavy, easily broken, and difficult to enlarge, and has a high degree of freedom in shape. Curved surface display is possible. Furthermore, since a roll-to-roll system is possible, the productivity is better than glass and it is advantageous in terms of cost reduction. In addition, the gas barrier property of water vapor or air is higher than that of a substrate using a conventional plastic or the like. For example, the problem of deteriorating the liquid crystal in the liquid crystal cell, resulting in a display defect and degrading the display quality can be solved. .
When used as a substrate for silicon-type or dye-sensitized solar cells, if the multilayer structure obtained in the present invention is used as a back sheet or a front plate, gas such as water vapor or oxygen is transferred to electrodes, semiconductors, dyes, electrolytes. It is possible to suppress deterioration of photoelectric conversion characteristics caused by acting on the liquid crystal. Moreover, since it is excellent also in heat resistance, it can be used suitably also when forming a silicon layer etc. with a thin film. Further, when used as an electronic component member, it is suitable for use as a printed wiring board because it is excellent in heat resistance and excellent in alkali resistance and acid resistance during etching.
When the multilayer structure obtained by the production method of the present invention is used for an exterior as a vacuum heat insulating material panel application, it has excellent gas barrier properties, so that the internal vacuum can be maintained over a long period of time, and heat is higher than that of aluminum foil or the like. Excellent resistance to thermal insulation because bridges are unlikely to occur.
Further, by using the multilayer structure obtained by the production method of the present invention as a packaging material, it is possible to prevent oxygen and water vapor deterioration of the contents packaged with the packaging material. When the multilayer structure is used as a packaging material, examples of its shape include a film, a bag, a bottle, a bottle cap, a box shape, a cup, a dish, a tray, a tank, and a tube. The contents packed by the multilayer structure obtained by the production method of the present invention include cakes, pastries such as castella, Japanese sweets such as Daifuku and mochi, snacks such as potato chips, and fishery products such as bamboo rings and rice cakes. Examples include processed products, miso, pickles, rice cakes, meatballs, hamburger, ham, sausage and other foods, beverages such as coffee, tea and juice, milk 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 coating liquids (1) to (7) and (9) described below are diluted, and the average particle diameter of the inorganic layered compound in the diluted liquid is measured at an optical path length of 4 mm with a flow cell. The average particle size L of the inorganic layered compound was considered.
In addition, without diluting these coating liquids (1) to (7) and (9), the average particle diameter of the inorganic layered compound in the coating liquid was measured at an optical path length of 50 μm with a paste cell. When the average particle size L obtained with the diluent almost coincided, the inorganic layered compound was determined to be sufficiently swollen and cleaved in the dispersion.

[Aspect ratio calculation]
Using an X-ray diffractometer (XD-5A, manufactured by Shimadzu Corporation), the inorganic layered compound itself was subjected to diffraction measurement by a powder method. As a result, the unit thickness a of the inorganic stratiform compound was determined, and the aspect ratio Z was calculated from the equation Z = L / a using the particle size L determined by the above-described method.

[Distance between inorganic layered compounds]
Using an X-ray diffractometer (XD-5A, manufactured by Shimadzu Corporation), diffraction measurement is performed by a powder method to determine the interlayer distance of the inorganic layered compound in the inorganic layered compound layer included in the preliminary structure and the multilayer structure. Asked.
In each of the examples and comparative examples, the same heat treatment as the drying treatment and heat treatment performed until the preliminary structure was obtained was performed on the coating liquids (1) to (7) and (9) containing the inorganic layered compound, and the above method Thus, the interlayer distance 1 was obtained. The interlayer distance 1 was considered as the interlayer distance of the inorganic layered compound in the inorganic layered compound layer in the preliminary structure.
Further, in each of the examples and comparative examples, the same heat treatment as the drying treatment and the heat treatment performed before obtaining the multilayer structure is performed on the coating liquids (1) to (7) and (9) containing the inorganic layered compound, The interlayer distance 2 was determined by the above method. The interlayer distance 2 was regarded as the interlayer distance of the inorganic layered compound in the inorganic layered compound layer in the multilayer structure.

[Measurement of cation concentration of inorganic layered compounds]
About the below-mentioned coating liquid (1)-(7), (9), the sodium ion and lithium ion density | concentration were measured using the inductively coupled plasma emission spectrometer (VISTA-PRO, Agilent Technologies). The sample preparation method is as follows. After 0.5 g of sample was collected in an evaporating dish, it was dry ashed (500 ° C.) with an electric furnace to remove organic substances. A residue obtained by dissolving the residue on the evaporating dish with 0.4 mL of 36% high-purity hydrochloric acid and diluting to 10 mL with ultrapure water was used as a measurement test solution, and sodium in the coating solutions (1) to (7) and (9) and The lithium concentration was measured. Thereafter, the sodium concentration and lithium ion concentration per 1 g of the inorganic layered compound are calculated from the solid content concentration of the inorganic layered compound dispersed in the coating liquids (1) to (7) and (9), Ion and lithium ion concentrations were used. For the coating solution (9), the ammonium ion concentration was measured using a capillary electrophoresis apparatus (capillary electrophoresis system, manufactured by Agilent Technologies). The sample preparation method is as follows. 1 mL of a sample was diluted with 1 mL of electrophoresis solution for capillary electrophoresis (20 mM imidazole / 5 mM lactic acid / 0.5 mM 18-crown-6-ether (pH 4.5)), and then an ultrafiltration filter (Ultrafree-MC30000 NMWL Filter Unit, MILLIPORE). The diluted sample was filtered using The solution was subjected to a capillary electrophoresis apparatus, and the ammonium ion concentration in the coating liquid (9) was measured. Thereafter, the ammonium ion concentration per gram of the inorganic layered compound was calculated from the solid content concentration of the inorganic layered compound dispersed in the coating liquid (9). Regarding the hydrogen ion concentration in the inorganic layered compound in the coating liquids (1), (2), (3), (4), (6), (7), the inorganic layered compound in the preliminary dispersion (6) The value was obtained by subtracting the sodium ion concentration in the inorganic layered compound formed using each coating solution from the sodium ion concentration inside.

(Appearance evaluation)
About the 50 mm x 50 mm size preliminary structure, the state of the coating film was visually confirmed and evaluated.
○ ・ ・ ・ Good. It is applied evenly.
X: Defect. It is applied unevenly. There is unevenness.

(Water resistance evaluation)
A multilayer structure having a size of 50 mm × 50 mm was immersed in water at 23 ° C. for 1 hour. Thereafter, peeling of the coating film was visually confirmed and evaluated.
○ ・ ・ ・ No peeling △ ・ ・ ・ Partial peeling × ・ ・ ・ Fully peeling

(Oxygen permeability measurement)
Based on JIS K7126, measurement was performed under conditions of 23 ° C. and 90% RH with an oxygen transmission rate measuring device (OX-TRANML, manufactured by MOCON).

[Preparation of coating solution]
(1) Preparation of coating liquid (1) With a stirrer, 1000 g of ion-exchanged water was stirred at high speed (3,000 rpm, peripheral speed = 8.2 m / min) at room temperature, and sodium pyrophosphate ( 0.75 g of Wako Pure Chemical Industries, Ltd.) is gradually added, and 60 g of high-purity montmorillonite (trade name: Kunipia G; manufactured by Kunimine Industries Co., Ltd.) is gradually added. Stirring was continued for a minute to obtain a preliminary dispersion (1).
60 g of H ⁺ type ion exchange resin (Duolite C255LFH; manufactured by Rohm & Haas) was added to the preliminary dispersion (1), and then stirred for 30 minutes to obtain a mixed liquid (1). Thereafter, the mixture (1) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin to obtain a coating solution (1). The cleaved montmorillonite average particle diameter L in the coating solution (1) was 560 nm, the value a obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (1) was 70 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the hydrogen ion concentration was 730 μmol / g.
(2) Preparation of coating liquid (2) In the preliminary dispersion liquid (1), the preliminary dispersion liquid (1) was prepared except that pyrophosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium pyrophosphate. 2) was obtained. 60 g of H ⁺ type ion exchange resin was added to the preliminary dispersion (2), and then stirred for 30 minutes to obtain a mixed liquid (2). Thereafter, the mixture (2) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin, thereby obtaining a coating solution (2). The cleaved montmorillonite average particle diameter L in the coating liquid (2) was 560 nm, the a value obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (2) was 50 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the hydrogen ion concentration was 750 μmol / g.
(3) Preparation of coating liquid (3) In the preliminary dispersion liquid (1), the preliminary dispersion liquid (1) was prepared in the same manner except that sodium sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium pyrophosphate. 3) was obtained. 60 g of H ⁺ -type ion exchange resin was added to the preliminary dispersion (3), followed by stirring for 30 minutes to obtain a mixed liquid (3). Thereafter, the mixture (3) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin to obtain a coating solution (3). The cleaved montmorillonite average particle diameter L in the coating solution (3) was 560 nm, the value a obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (3) was 170 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the hydrogen ion concentration was 630 μmol / g.
(4) Preparation of coating liquid (4) In the preliminary dispersion liquid (1), the preliminary dispersion liquid (1) was prepared in the same manner except that sodium acetate (manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium pyrophosphate. 4) was obtained. 60 g of H ⁺ type ion exchange resin was added to the preliminary dispersion (4), and then stirred for 30 minutes to obtain a mixed liquid (4). Thereafter, the mixture (4) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin to obtain a coating solution (4). The cleaved montmorillonite average particle diameter L in the coating solution (4) was 560 nm, the a value obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (4) was 60 μmol / g, the lithium ion concentration was below the measurement limit value, and the hydrogen ion concentration was 740 μmol / g.
(5) Preparation of coating solution (5) 50 cc of ion exchange resin (Duolite C-20LF; manufactured by Rohm & Haas Co.) and 500 g of 10% lithium chloride aqueous solution were mixed, followed by high-speed stirring (3,000 rpm, circumference) Speed = 8.2 m / min), and then the ion exchange resin was recovered to produce a Li ⁺ type ion exchange resin.
A coating liquid (5) was obtained in the same manner as the coating liquid (1) except that the Li ⁺ type ion exchange resin was used instead of the H ⁺ type ion exchange resin. The cleaved montmorillonite average particle diameter L in the coating solution (5) was 560 nm, the a value obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (5) was 80 μmol / g, and the lithium ion concentration was 740 μmol / g.
(6) Preparation of coating liquid (6) Preliminary dispersion liquid (6) was obtained in the same manner as in preliminary dispersion liquid (1) except that sodium pyrophosphate was not added. 60 g of H ⁺ -type ion exchange resin was added to the preliminary dispersion (6), followed by stirring for 30 minutes to obtain a mixed liquid (6). Thereafter, the mixture (6) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin to obtain a coating solution (6). The cleaved montmorillonite average particle diameter L in the coating solution (6) was 560 nm, the value a obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (6) was 320 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the hydrogen ion concentration was 480 μmol / g.
(7) Preparation of coating liquid (7) In the preliminary dispersion liquid (1), the preliminary dispersion liquid (1) was prepared except that ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium pyrophosphate. 7) was obtained. 60 g of H ⁺ type ion exchange resin was added to the preliminary dispersion (7), followed by stirring for 30 minutes to obtain a mixed liquid (7). Thereafter, the mixture (7) was filtered using a filter (fluid aperture of 297 μm) to remove the residue of the ion exchange resin to obtain a coating solution (7). The cleaved montmorillonite average particle diameter L in the coating solution (7) was 560 nm, the a value obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (7) was 80 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the hydrogen ion concentration was 720 μmol / g.
(8) Preparation of coating liquid (8) In a dispersion kettle (trade name: Despa MH-L, manufactured by Asada Tekko Co., Ltd.), 206 g of cyclohexanone and a cresol novolac-type epoxy compound (manufactured by Unidic V8000C1 DIC Corporation) 25.8 g and 100 g of polyimide skeleton-containing compound (Unidic V8000 DIC Co., Ltd.) are mixed, stirred at high speed (3000 rpm, peripheral speed = 8.2 m / min), and dissolved by stirring for 30 minutes at room temperature. The coating liquid (8) used in order to form a heat-reactive composition layer was obtained.
(9) Preparation of coating liquid (9) 50 cc of ion exchange resin (Duolite C-20LF; manufactured by Rohm & Haas) and 500 g of 10% aqueous ammonium chloride solution were mixed, and then stirred at high speed for 30 minutes (3,000 rpm, circumference (Speed = 8.2 m / min), and then the ion exchange resin was recovered to produce an NH 4 ⁺ type ion exchange resin.
A coating liquid (9) was obtained in the same manner as the coating liquid (1) except that the NH4 ⁺ type ion exchange resin was used instead of the H ⁺ type ion exchange resin. The cleaved montmorillonite average particle diameter L in the coating liquid (9) was 560 nm, the a value obtained from powder X-ray diffraction was 1.22 nm, and the aspect ratio Z was 460. The sodium ion concentration per gram of the inorganic layered compound contained in the coating solution (9) was 150 μmol / g, the lithium ion concentration was not more than the lower limit of measurement, and the ammonium ion concentration was 500 μmol / g.

[Example 1]
A polyimide film having a thickness of 50 μm (Kapton 200H / V, manufactured by Toray DuPont Co., Ltd .: PI) was used for the base material layer. The substrate layer is subjected to a corona treatment, and the above-mentioned coating solution (8) is applied to the corona-treated surface with a bar coater (number: 8), followed by a drying treatment (80 ° C., 20 minutes). A heat-reactive composition layer (I) was formed thereon. Thereafter, the coating solution (1) was applied on the heat-reactive composition layer (I) with a bar coater (count: 28) and dried (80 ° C., 20 minutes) in the same manner as described above. The inorganic layered compound layer (I) was formed to obtain a preliminary structure (1). The preliminary structure (1) was heat-treated at 200 ° C. for 3 hours in an air atmosphere to obtain a multilayer structure (1) composed of a base material layer, a resin layer, and an inorganic layered compound layer. The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (1) was evaluated. The results are shown in Table 1.

[Example 2]
A multilayer structure (2) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (2) was used instead of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (2) was evaluated. The results are shown in Table 1.

[Example 3]
A multilayer structure (3) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (3) was used instead of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (3) was evaluated. The results are shown in Table 1.

[Example 4]
A multilayer structure (4) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (4) was used in place of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (4) was evaluated. The results are shown in Table 1.

[Example 5]
A multilayer structure (5) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (5) was used instead of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (5) was evaluated. The results are shown in Table 1.

[Comparative Example 1]
A multilayer structure (6) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (6) was used instead of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (6) was evaluated. The results are shown in Table 1.

[Comparative Example 2]
A multilayer structure (7) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (7) was used instead of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (7) was evaluated. The results are shown in Table 1.
[Example 6]
A multilayer structure (8) composed of a base material layer, an inorganic layered compound layer and a resin layer was obtained in the same manner as in Example 1 except that the coating liquid (9) was used in place of the coating liquid (1). The resin layer had a thickness of 0.5 μm, and the inorganic layered compound layer had a thickness of 2 μm. Thereafter, the multilayer structure (8) was evaluated. The results are shown in Table 1.

Claims (4)

An inorganic layered compound dispersion comprising one or more compounds selected from the group consisting of oxoacids and metal salts of oxoacids, an inorganic layered compound, and a liquid medium,
An inorganic layered compound dispersion in which the amount of sodium ions contained in the dispersion is 300 μmol or less per 1 g of the inorganic layered compound contained in the dispersion.   The inorganic layered material according to claim 1, wherein the one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids are one or more compounds selected from the group consisting of oxo acids and sodium salts of oxo acids. Compound dispersion.   When the total weight of one or more compounds selected from the group consisting of oxo acids and metal salts of oxo acids contained in the dispersion and the inorganic layered compound is 100% by weight, the metal salts of oxo acids and oxo acids The inorganic layered compound dispersion according to claim 1 or 2, wherein the ratio of one or more compounds selected from the group consisting of 0.01 to 10% by weight. A layer containing at least one inorganic layered compound selected from the group consisting of an inorganic layered compound having hydrogen ions between layers, an inorganic layered compound having lithium ions between layers, and an inorganic layered compound having ammonium ions between layers; A method for producing a multilayer structure including a layer, comprising the following steps (1) and (2).
Step (1): The inorganic layered compound dispersion according to any one of claims 1 to 3 is applied to the surface of the base material layer to form a coating film, and then dried under temperature conditions of 20 to 150 ° C. A step of producing a preliminary structure including the base material layer and the inorganic layered compound layer (I) by removing the liquid medium from the coating film.
Step (2): a step of heat-treating the preliminary structure to reduce the interlayer distance of the inorganic layered compound in the inorganic layered compound layer (I) to obtain a multilayer structure.