JP2002036417A - Gas barrier laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier laminate with superb gas barrier properties which is useful as a material for various kinds of packages and shows the high water resistance of a gas barrier layer and also high coating film strength. SOLUTION: In the gas barrier laminate having the gas barrier layer formed at least on one of the sides of a support, the gas barrier layer has the following three layers sequentially laminated and formed from the support side: (1) a first layer containing a nitrogen-containing compound which chemically reacts with a silicic acid condensate, (2) a second layer containing at least one kind of the silicic acid condensate selected from an alkali silicate metallic salt or colloidal silica, and a platelike pigment, and (3) a third layer containing a highly hydrogen-bonding resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier laminate which is suitable as various packaging materials, molded articles or molding materials.

[0002]

2. Description of the Related Art In the packaging of foods and the like, gas barrier properties, particularly barrier properties of oxygen, water vapor, carbon dioxide, and aroma (aroma, flavor) are important qualities from the viewpoint of protecting the quality of contents. Packaging materials using such barrier materials include confectionery bags, bonito packs, retort pouches, meat packaging such as ham and sausage, seafood packaging, dairy packaging, miso packaging, tea and coffee packaging. It is used in many fields, such as packaging of carbon dioxide beverage containers, cosmetics, agricultural chemicals and pharmaceuticals. On the other hand, polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyamide resins such as nylon 6 and nylon 66; A plastic resin is widely used as a packaging material because of its excellent strength, heat resistance, transparency, and the like. However, when a film made of these thermoplastic resins is used as a packaging material, the gas barrier property is insufficient, so that the film is laminated with a thermoplastic resin having gas barrier properties, an aluminum foil, an aluminum-deposited film, a silicon-deposited film, or the like. In general, a packaging material is used.

As thermoplastic resins having high gas barrier properties, polyvinyl alcohol (PVA), ethylene vinyl alcohol (EVOH, saponified product of ethylene-vinyl acetate copolymer), polyalcohol (reduced product of polyketone), vinylidene chloride ( PVDC) and the like, but a resin exhibiting a barrier property by a hydrogen bond due to a hydroxyl group such as PVA or EVOH has a sharp decrease in the barrier property at high humidity (for example, 20 ° C. and 80% RH or more). There's a problem. Also, since PVDC is a chlorine compound, problems such as the generation of dioxins may occur during incineration. In recent circumstances, it has been attempted to refrain from using it as a packaging material as much as possible in order to raise awareness of global environmental issues. is there.

On the other hand, as a method for improving the gas barrier property of a high hydrogen bonding resin, Japanese Patent Application Laid-Open No. 7-251489 discloses a gas barrier layer containing a high hydrogen bonding resin and an inorganic layered compound. However, the gas barrier film obtained in such a technique has a high hydrogen bonding resin generally having a hydrophilic polar group, and the polar group easily forms a hydrogen bond with a water molecule, so that the resin itself easily swells. . Since oxygen molecules easily pass through such swollen molecular chains, the gas barrier properties of the coating deteriorate, and although the inorganic layered compound is added, the gas barrier properties that are always satisfactory under high humidity conditions are not necessarily achieved. It is hard to say that it can be obtained.

In the prior art using an alkali metal silicate solution, an aqueous liquid comprising an alkali metal silicate solution and a coupling agent is applied to the surface of a polymer molded article to form a thin film and form a gas barrier layer. Method for obtaining body
238711) and a method of mixing an aqueous solution of sodium silicate, which is an alkali metal silicate, and an aqueous solution of lithium silicate to obtain a gas barrier material from the mixture (Japanese Patent Application Laid-Open No. 7-18202). The former has the advantage that it can be manufactured at low cost without performing operations such as vapor deposition, but it may still have insufficient gas barrier properties, and still has problems in terms of coating film strength and water resistance. In addition, it is difficult to say that the gas barrier film containing the alkali metal silicate as a main component completely solves the problems of insufficient water resistance and crack generation of the alkali metal silicate coating.

On the other hand, there is a conventional technique utilizing hydrolysis of a metal alkoxide. Japanese Patent No. 2,556,940 discloses a technique of polycondensing a composition containing an alkoxysilane, a silane coupling agent and polyvinyl alcohol to form a gas barrier laminate film from a composite polymer whose main component is a linear polymer. Has been described. However, even with this method, satisfactory results have not yet been obtained for gas barrier properties under high humidity.

Further, Japanese Patent Application Laid-Open No. 11-129379 discloses a gas barrier laminate comprising a hydrolyzate of an inorganic layer compound, a resin and a metal alkoxide.
In this method, a hydrolyzate of a metal alkoxide is further added to a coating mainly composed of an inorganic layered compound and a resin. However, in such a method, the hydrolyzate of the metal alkoxide added later rapidly condenses with the resin, and the reaction proceeds to form a random three-dimensional network structure. The gas barrier layer formed in this manner must be porous, and although an inorganic layered compound is added, a high barrier property cannot be expected.

[0008] Of the silicic acid condensates, the alkali metal silicate is also called water glass, and sodium silicate,
Examples include lithium silicate and ammonium silicate. The colloidal silica is typically a colloidal particle obtained by subjecting an alkali metal silicate to a dealkalization treatment using an ion exchange resin, followed by condensation.

Both alkali metal silicates and colloidal silicas are ultrafine particles whose primary particles are smaller than nanometers or nanometers. In a solution, monomers, dimers, trimers, octomers, and oligomers condensed with them are dispersed. Many particles are included, and the particles have reactive functional groups on the surface, and not only can each particle be spread at the time of film formation, but also have the advantage that when dried, a condensation reaction occurs and a uniform barrier film can be made .

The present inventors have conducted intensive studies on gas barrier films using these silicic acid condensates, and have disclosed in Japanese Patent Application Nos.
No. 6984 filed an application for a gas barrier laminate in which cracks were completely prevented by combining a silicic acid condensate and a tabular pigment. However, if only the silicic acid condensate and the tabular pigment are used for a long period of time at high temperature and high humidity, the water resistance will be insufficient, and they may peel off from the support or cracks may occur. The current situation was forced to do so.

As for this problem, as a result of repeated studies,
By using a nitrogen-containing compound that reacts with a silicic acid condensate to promote the condensation of the silicic acid condensate, a gas barrier laminate having excellent water resistance and adhesion has been obtained (Japanese Patent Application 2000
-067858). However, since the silicic acid condensate film is inorganic, it has the advantage of being hard and not easily scratched, but on the other hand, when used as a packaging material,
There is one aspect that the bending resistance is insufficient depending on the intended use. Further, when an alkali silicate is used as the silicic acid condensate, the alkali silicate is strongly alkaline, so that it has a disadvantage that it absorbs moisture or carbon dioxide gas in the air, causing the coating film to turn white and significantly impair the appearance. As described above, the gas barrier film containing the silicate condensate and the plate-like pigment has insufficient flex resistance depending on the intended use when it is used as a packaging material, and when an alkali silicate is used, the gas barrier film is liable to an alkali metal. The problem of efflorescence originating still remains, and its use as a packaging material has been limited.

[0012]

DISCLOSURE OF THE INVENTION The present invention relates to a gas barrier film comprising alkali metal silicate or colloidal silica, which has improved gasket resistance and suppresses the occurrence of efflorescence and is suitable as a packaging material. A laminate is provided.

[0013]

For this purpose, the present invention has the following structure. 1. A gas barrier laminate having a gas barrier layer formed on at least one surface of a support, wherein the gas barrier layer is formed by sequentially laminating the following three layers from the support side. (1) A first layer containing a nitrogen-containing compound that reacts with a silicic acid condensate. (2) A second layer containing at least one silicic acid condensate selected from alkali metal silicate or colloidal silica, and a tabular pigment. (3) A third layer containing a high hydrogen bonding resin. 2. 2. The gas barrier laminate according to 1, wherein the high hydrogen bonding resin is a resin selected from one of polyvinyl alcohol and an ethylene-vinyl alcohol copolymer. 3. When the silicic acid condensate has the general formula M ₂ O.nSiO ₂ (provided that
In the formula, n is a number of 0 or more, and M represents Na or Li)
3. The gas barrier laminate according to any one of 1 to 2, which is at least one selected from sodium silicate and lithium silicate represented by: 4. 4. The gas barrier laminate according to any one of 1 to 3, wherein the first layer contains a water resistance improver. 5. 5. The gas barrier laminate according to any one of 1 to 4, wherein the nitrogen-containing compound is at least one compound selected from polyalkyleneimines and polyalkyleneamines. 6. 6. The gas barrier laminate according to any one of 1 to 5, wherein the tabular pigment is one or more pigments selected from smectite clay and mica.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
A first aspect of the present invention relates to a gas barrier laminate having a gas barrier layer formed on at least one surface of a support. The support in the present invention refers to a film or a plastic molded product made of a thermoplastic resin such as polyolefin such as polyethylene and polypropylene, polyester, polyamide, polycarbonate and polynaphthalene. Further, the gas barrier layer formed on the support may be a first layer containing a nitrogen-containing compound that reacts with the silicic acid condensate, and at least one silicic acid condensate selected from alkali metal silicate and colloidal silica. It is formed by sequentially laminating a second layer containing a pigment-like pigment and a third layer containing a high hydrogen bonding resin.

Conventionally, when a functional layer is formed on a support made of a thermoplastic resin or the like, in order to improve the adhesion to the support, a treatment with a mixed acid solution of a black acid, a corona discharge treatment,
There is known a method of imparting a polar group to a support surface by a physical treatment such as a flame treatment, a silane coupling agent treatment, a titanium coupling agent treatment, an ionomer layer forming treatment, a polycation treatment, or a chemical treatment.

In the present invention, the above-mentioned physical treatment or chemical treatment is applied to a support, and a hydrophilic polar group such as a hydroxyl group, a carbonyl group, a carboxyl group, or an amino group is imparted to the surface of the support. A layer containing a nitrogen-containing compound that reacts with the substance is formed as a first layer on the surface of the support. The nitrogen-containing compound in the first layer adheres firmly to the hydrophilic polar group on the surface of the support by hydrogen bonding. In particular, when the polar group on the surface of the support is anionic, the nitrogen-containing compound has cationicity. Therefore, the anionic polar group on the support surface and the cationic group of the nitrogen-containing compound are strongly ion-bonded, and the second Since the anionic silicate condensate and the anionic tabular pigment contained in the layer are firmly adhered by ionic bonding or dehydration condensation, the adhesion between the support and the gas barrier layer is greatly improved. Further, it is preferable that the first layer containing the nitrogen-containing compound and the second layer containing the silicic acid condensate have a gradient structure in which the concentrations are continuously changed by mixing. When the nitrogen-containing compound is an organic compound, the organic / inorganic composition has a gradient structure, so that not only the organic layer improves the adhesion to the support and the gas barrier property of the inorganic layer is compatible, but also the stress strain is increased. To some extent. However, it is difficult to say that only the first and second layers have sufficient bending resistance. The inventors of the present invention have conducted intensive studies and have found that the provision of the third layer containing a high hydrogen bonding resin on the second layer dramatically improves the bending resistance. This is because not only the third layer acts as a simple protective layer, but also the silanol groups of the silicic acid condensate of the second layer and the hydroxyl groups of the high hydrogen bonding resin of the third layer form hydrogen bonds or covalent bonds. so,
It is thought that it is to form a strong network.

The provision of the third layer made of a highly hydrogen-bonding resin is advantageous in forming an alkali silicate coating film.
It has been found that it is also effective for the efflorescence phenomenon, which is always a problem. This is considered to be because the high hydrogen bonding resin suppresses bleeding of the alkali metal contained in the alkali silicate onto the surface of the coating film, thereby preventing crystal growth on the surface of the coating film.

The nitrogen-containing compound in the first layer not only improves the adhesion between the support and the gas barrier layer, but also reacts with the silicic acid condensate to promote the condensation of the silicic acid condensate, thereby reducing the silicic acid condensate. High water resistance and good gas barrier properties to the gas barrier layer containing the substance. Considering this in more detail,
Nitrogen-containing compounds that react with such silicic acid condensates not only form complexes with the silanol groups on the surface of the silicic acid condensates, but also form hydroxyl ions to form silanol groups that do not form complexes. It is thought that the water resistance is improved by promoting condensation and expanding the network of siloxane bonds newly.
As another mechanism, it is considered that the interface between the silicic acid condensate and the tabular pigment is filled with the nitrogen-containing compound, and the nitrogen-containing compound and the tabular pigment are connected by an ionic bond, thereby improving the water resistance. Further, since the surface of the flat pigment is generally hydrophilic and anionic, it is considered that the surface of the flat pigment is reacted with the cationic nitrogen-containing compound to make the surface of the flat pigment hydrophobic.

The silicic acid condensate shows ionicity in water, and exists as a dissolved monomer, dimer, trimer, tetramer or an oligomer obtained by condensing them. When these silicic acid condensates are dried to form a film, the silanol groups condense to form siloxane bonds. For this reason, the coating usually shrinks in volume and peels off between the support and the coating, and the coating is apt to fall off or cracks frequently, so that only a very fragile coating is obtained.

The present inventors have also conducted intensive studies on this point, and as a result, they have found that the combined use of a silicate condensate and a platy pigment enables the platy pigment to exhibit resistance to volume shrinkage. A similar concept is in the field of plastic molding. For example, a method has been adopted in which a glass fiber is kneaded with a plastic to thereby prevent the occurrence of craze that may lead to destruction when an impact is applied, thereby obtaining a reinforced plastic. Also in the present invention, by mixing a plate-like pigment, it is possible to prevent the occurrence of cracks due to the condensation of the silicic acid condensate and increase the strength of the film made of the silicic acid condensate. Such effects are difficult to obtain with spherical pigments typified by calcium carbonate, and are effects unique to tabular pigments.
Moreover, since the tabular pigment has a large specific surface area and its surface is hydrophilic, the silanol groups of the silicic acid condensate in contact with the surface of the tabular pigment cannot be condensed. As a result, it is considered that the tabular pigment having a large specific surface area inhibits the condensation of silicic acid to prevent cracks.

As described above, the tabular pigment not only has an effect of preventing the occurrence of cracks due to shrinkage accompanying the condensation of the silicic acid condensate, but also has an effect unique to gas barrier properties. The tabular pigment is a pigment having a substantially flat property and a ratio of the major axis to the thickness (aspect ratio) of 5 or more. In the present invention, a gas condensate and a plate-like pigment are blended in the gas barrier layer, and the plate-like pigment is spread like a fish scale in the gas barrier layer to prevent gas from entering. The tabular pigment is an inorganic substance having crystallinity,
No gas molecules permeate from the plane direction to the thickness direction. In the present invention, such a flat pigment is spread,
When the tabular pigments are stacked in layers in the thickness direction of the layer, a so-called curved-path effect is exhibited in which gas molecules to be permeated pass around the tabular pigment. Therefore,
As compared with the case where a pigment having a shape close to a sphere, such as calcium carbonate, which is a general-purpose pigment, is used, gas barrier properties that are several times better can be obtained.

Such a plate-like pigment is preferably an inorganic layer compound having a layer structure in which unit crystal layers are stacked on each other. A “layered compound” is a compound or substance having a layered structure. A “layered structure” refers to a surface in which atoms are strongly bonded by covalent bonds or the like and are densely arranged, and a weak binding force such as van der Waals force. Refers to pigments having a high flatness and a structure stacked in parallel with each other or bonded with ions.

The silicic acid condensate used in the present invention contains at least one selected from alkali metal silicate and colloidal silica.

The alkali metal silicate is M ₂ O.nSiO ₂
(M is an alkali metal, n> 0). The alkali metal M of the alkali metal silicate is lithium,
It is an alkali metal such as sodium or potassium or a cationic ion such as ammonium. The alkali metal silicate is usually handled as a concentrated aqueous solution. n is also called a molar ratio and is usually a value of about 0.5 to 10. If the molar ratio is less than 0.5, the amount of the alkali metal is too large, which often results in a decrease in the water resistance, and the efflorescence phenomenon easily occurs. Those with more than 10 are not generally commercially available.

However, the alkali metal silicate having a high molar ratio exceeding 10 can be obtained by adding various alkali metal hydroxides to amorphous silica or colloidal silica and dissolving the same, or by adding amorphous metal silicate to a commercially available alkali metal silicate. It can be prepared by a method of dissolving silica or colloidal silica. A high molar ratio alkali metal silicate prepared by such a method is also within the scope of the present invention. When a high molar ratio alkali metal silicate is used, a very thin plate-like pigment having a specific shape is used, or an ultra-thin film of 0.5 μm or less is formed. Cracks are less likely to occur when the degree of shrinkage is set to the same level.

Colloidal silica can be obtained by neutralizing sodium silicate with an inorganic acid at room temperature or hydrolyzing a silicon ester or silicon halide. Further, after passing an alkali metal silicate such as sodium silicate through the cation ion exchange resin layer, the pH is adjusted with an alkali, and then the mixture is heated to generate a core of colloidal silica, and the solution is further passed through the cation exchange resin layer. It can be obtained by slowly dropping the obtained sodium silicate solution. In this case, if the dropping speed is increased rapidly, the condensation proceeds rapidly, and aggregation occurs, resulting in a porous structure, which is not preferable. By slowly dropping the monomers, the monomers are sequentially deposited on the silanol groups on the nucleus surface, and the particles grow. Colloidal silica can be arbitrarily grown from several nm to several μm in size by appropriately adjusting the pH and slowing the dropping rate.
The particle diameter of such colloidal silica is preferably several nm to several hundred nm. Further, the packing ratio can be increased by combining colloidal silicas having different particle diameters.

Of the alkali metal silicates and colloidal silica, alkali metal silicates are preferred from the viewpoint of gas barrier properties only. As the alkali metal silicate, when the alkali metal is sodium silicate,
Sodium orthosilicate (Na ₂ O · 1 /
2SiO ₂ or Na ₄ SiO ₄ ), sodium sesquisilicate with a molar ratio of 0.67 (3Na ₂ O · 2SiO ₂ or Na ₆ Si ₂ O ₇ ), sodium metasilicate with a molar ratio of 1 (N
a ₂ O.SiO ₂ or Na ₂ SiO ₃ ), sodium disilicate (Na ₂ O.2SiO ₂ or Na ₂ S) having a molar ratio of 2
i ₂ O ₅ ), sodium tetrasilicate (Na ₂ O · 4
SiO ₂ or Na ₂ Si ₄ O ₉ , also known as sodium silicate 4
No.) and Japanese Industrial Standard JIS-K-14
Sodium silicate No. 1 (molar ratio 2), No. 2 (molar ratio 2.5), No. 3 (molar ratio 3), one kind of sodium metasilicate, and two kinds of sodium metasilicate specified in 08.

Potassium silicate in which the alkali metal is potassium
The composition of the system also varies, but as an example
Potassium metasilicate (K_TwoO ・ SiO_Two), Potassium tetrasilicate
(K _TwoO ・ 4SiO_Two・ H_TwoO, also known as potassium disilicate
). Silicic acid whose alkali metal is lithium
Lithium is lithium orthosilicate (Li_TwoO1 / 2Si
O_Two), Lithium metasilicate (Li_TwoO ・ SiO_Two), 3.
5 lithium silicate, 7.5 lithium silicate (Li_TwoO.7.
5SiO_Two)and so on.

Further, ammonium salts such as ammonium silicate having tetramethylammonium ion as a counter ion are also included in the scope of the present invention.

These alkali metal silicates have different degrees of condensation and different particle sizes depending on the molar ratio. The size cannot be clearly determined as the molar ratio decreases as the solubility in the liquid increases. However, by analogy with the dynamic light scattering method, most of them have a size of several nm or less. As can be densely packed.

The paint containing the alkali metal silicate of the present invention may be mainly composed of the aqueous solution of the alkali metal silicate. Further, an aqueous solution obtained by mixing two or more kinds of alkali metal silicates may be mainly used.

Next, as the flat pigment used in the present invention, firstly, a phyllosilicate mineral can be mentioned. Those belonging to phyllosilicate minerals are plate-like or flaky and have distinct cleavage properties, mica, pyrophyllite, talc, chlorite, septe chlorite, serpentine, stilp-nomelane, There are clay minerals and the like. Among these, minerals having a large particle size and a large amount of output, such as mica and talc, are preferred. Mica includes muscovite (muscovite), sericite (sericite), biotite (flokopite), biotite (biotite), fluorophlogopite (artificial mica), red mica, soda mica, vanadin mica, illite, Chin mica, paragonite, brittle mica and the like. Of course, synthetic products such as synthetic mica similar in composition to talc are also included in the scope of the present invention.

Clay minerals such as kaolin are also generally referred to as flat crystals, but if one crystal is taken, there is a flat portion but the whole is granular. However, among kaolins, delamikaolin, which is intentionally separated from the crystal layer and cut into a flat plate, can be used in the present invention.
When delamikaolin or the like is used as a pigment, the particle diameter of the pigment used in the gas barrier layer may need to be reduced according to the film thickness, and these pigments may be pulverized by a ball mill, sand grinder, cobol mill, jet mill, or the like. It is necessary to classify by pulverization and classification with a machine to a desired size.

Secondly, the so-called inorganic layered compound having a high tabularity, which is a stacked structure or bonded with ions, is also effective as the tabular pigment used in the present invention. Specific examples of the inorganic layer compound include graphite, phosphoric acid salt derivative type compounds (zirconium phosphate compound), chalcogen compound [dichalcogen compound represented by the formula MX ₂ is illustrated. Here, M represents an element belonging to Group IV (Ti, Zr, Hf), Group V (V, Nb, Ta) or Group VI (Mo, W), and X represents a chalcogen (S, Se, Te). ].

As a third of the tabular pigments used in the present invention,
Examples include clay minerals such as smectites and vermiculites. More specifically, mention may be made of dickite, nacrite, smectite, halloysite, antigorite, chrysotile, pyrophyllite, tetrasilyl mica, sodium teniolite, margarite, vermiculite, zansophyllite, chlorite, etc. it can. Also, a layered polysilicate,
Kanemite, macatite, islayite, makadiite, kenyaite and the like can also be mentioned.

Of these, smectite clay is particularly preferred. The smectite viscosity is composed of crystals having a three-layer structure, and montmorillonite, beidellite, nontrolite, saponite, iron saponite, hectorite, sauconite, stippnsite, hectite and the like are known.

These smectite clays are light yellow or white fine powders having a size of several nm to several μm.
It swells in water to create a unique colloidal structure. For example,
Montmorillonite has a three-layer structure in which an alumina layer is sandwiched between two silicas as one unit, and the flakes are connected via water. In an aqueous solution, the flakes are separated because of the water between the flakes.

In general, when smectite clay is dispersed in water, a colloidal dispersion, that is, a sol is easily formed. However, as the concentration increases, a gel is easily formed, and remarkable thixotropic properties are exhibited. For this reason, it is difficult to prepare a smectite clay dispersion having a high concentration. In such a case, it is preferable to add a deflocculant since a stable fluid dispersion (sol) is obtained and the viscosity of the coating material is reduced. Examples of the deflocculant include polyvalent phosphates such as hexametaphosphate and polyphosphate (such as sodium pyrophosphate).
In particular, sodium pyrophosphate is preferable because of its excellent performance / price ratio.

The particle size of the tabular pigment is from 10 nm to 5 μm
Are preferred, more preferably 10 nm
From about 1 μm. If it is less than 10 nm, the flatness does not work effectively, it is difficult to arrange the coating layer in parallel with the support during drying, and it is difficult to exhibit a curved path effect. On the other hand, if it exceeds 5 μm, the appearance is poor and the film forming property of the silicic acid condensate is undesirably reduced.

The tabular compound that can be used in the present invention is not particularly limited as long as it has a particle size of 10 nm to 5 μm or less. From the viewpoint of the transparency of the gas barrier laminate, the particle size is 1 μm or less. Is preferred. Further, when the gas barrier laminate is a film, particularly when used for applications where transparency is important (for example, food applications), the particle size is more preferably 0.5 μm or less. The transparency is 80% or more (more preferably 85% or more) in total light transmittance at a wavelength of 500 nm and haze is 0.5 to 1%.
Preferably, it is within the range of 0%. Such transparency can be measured, for example, by using a commercially available spectrophotometer (Shimadzu self-recording spectrophotometer U
V-3100PC: manufactured by Shimadzu Corporation).

Next, from the viewpoint of gas barrier properties, the tabular pigment has an aspect ratio of the average particle size divided by the thickness of 2 or more.
More preferably, it is 0 or more. If the aspect ratio is less than 20, the curved road effect may be small and the gas barrier properties may be insufficiently developed depending on the application. On the other hand, it is technically difficult to obtain an inorganic layered compound having an aspect ratio exceeding 1000, and it is economically expensive. From the viewpoint of manufacturability, the aspect ratio is preferably 1000 or less. For the measurement of the particle size of such a plate-like pigment, a measuring device of a light scattering method can be used, but in the present invention, the average particle size is determined by direct observation using a transmission electron microscope or a scanning electron microscope. The diameter was determined. The aspect was determined by searching for a rod-shaped material other than scales in the field of view of the electron microscope and setting the thickness.

The ratio of the silicic acid condensate to the pigment is 9 by mass.
It is in the range of 5/5 to 5/95. For tabular pigments,
For example, smectite clay such as montmorillonite can easily form a coating due to its flatness and surface charge.
Of course, since the strength of the coating is low and the water resistance is low, it is necessary to reinforce with a silicic acid condensate. On the other hand, if the silicic acid condensate alone is used, the coating is liable to crack with the condensation, but the addition of a tabular pigment can significantly reduce the occurrence of cracks. As described above, the silicic acid condensate and the tabular pigment work to compensate for each other. For this reason, the ratio of the silicic acid condensate to the tabular pigment can be in a wide range as described above. However, from the viewpoint of the strength of the gas barrier film, the greater the proportion of the silicic acid condensate, the higher the practicality, and the ratio of the silicic acid condensate to the tabular pigment is preferably about 90/10 to 30/70 by mass.

Examples of the nitrogen-containing compound that reacts with the alkali metal silicate or colloidal silica used in the present invention include cationic organic compounds. Silicic acid condensates such as alkali metal silicates have both silanol groups and dissociated silanol ions in the alkaline region, and these functional groups condense to form siloxane bonds. As a result of repeated studies by the present inventors, when a cationic organic compound is used, the cationic organic compound not only causes a reaction such as an ionic bond or a covalent bond with a silicic acid condensate, but also generates a hydroxyl compound generated by the cationic organic compound. It has been found that the ion promotes the condensation reaction of the silicic acid condensate. When showing a case cationic organic compound is a polyamine as an example, the cation ion reaction of a silanol ion and the polyamine silicate condensate (~SiO ^- ... N ⁺ ~) or covalent bonds (~
Gelation by SiO-N ~). On the other hand the, OH by the action of an amine ^- ... H: OH produced by N ⁺ form of ~ ^- what is prompted condensation of silanol groups of the silicate condensate, to expand the network of siloxane bonds to generate new siloxane bonds it is conceivable that.

Representative of these nitrogen-containing compounds are those referred to as imine compounds and amine compounds. Among these, polyalkylene imines are typical examples of imine compounds, such as polyethylene imine, alkyl or cyclopentyl-modified polyethylene imine, imine adduct of ethylene urea, ethylene imine adduct of poly (ethylene imine-urea) and polyamine polyamide, or There is a polyimine-based compound selected from the group consisting of these alkyl-modified, alkenyl-modified, benzyl-modified or aliphatic cyclic hydrocarbon-modified, polyamideimide, and polyimide varnish.

As the amine compound, there is a polyalkylene polyamine. For example, polyethylene polyamine,
Compounds such as ethylenediamine, diethylenetriamine, and triethylenetetramine. Examples of the same effect include polyamides such as polyamide imide adducts of polyamides, hydrazine compounds,
Epichlorohydrin adduct of polyamine polyamide (a water-soluble, cationic thermosetting resin obtained by reacting a polyamide with epichlorohydrin from a saturated dibasic carboxylic acid having 3 to 10 carbon atoms and a polyalkylene polyamine), etc. And quaternary nitrogen-containing acrylic polymers, quaternary nitrogen-containing benzyl polymers, urethanes, compounds having an amine carboxylate group, compounds such as methylolated melamine, and cationic polyurethanes. Further, cationic resins such as a cation-modified polyurethane resin, polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer, and a tertiary nitrogen-containing acrylic resin can be used (for the cationic resin, JP-A-8-90898, 63-1
62275 and JP-A-62-148292). Further, urea compounds such as urea, thiourea, guanylurea, methylurea, and dimethylurea, and dicyandiamide derivatives are also included in the scope of the present invention.

More specifically, the polyalkyleneimine used in the present invention is preferably polyethyleneimine or polypropyleneimine, and particularly preferably polyethyleneimine. These polyalkyleneimines may be used alone or may be used after forming a salt with acetic acid, p-toluenesulfonic acid, sulfuric acid, hydrochloric acid or the like.

The organic amine compound may be any of a primary amine compound, a secondary amine compound, a tertiary amine compound, and a quaternary ammonium salt compound.
Further, any of an organic monoamine and an organic polyamine may be used. Further, the organic amine compound includes those having a different functional group other than the amino group, for example, an epoxy group, a hydroxyl group, a carboxylic acid group, a nitrile group and the like.

Examples of the modified organic amine compound include an adduct of an amine compound with a compound having an epoxy group such as a monoepoxy compound and a diepoxy compound, an adduct of an amine compound with a compound having a hydroxyl group such as ethylene oxide and propylene oxide, and an acrylic compound. Examples include a Michael adduct of a nitrile and an amine compound, and an adduct obtained by a Mannich reaction of a phenol compound, an aldehyde compound, and an amine compound.

The above-mentioned modifications include 1) reducing the toxicity of the amine compound, such as irritating odor and skin irritation, 2) reducing the viscosity of the amine compound, and 3) increasing the molecular weight and weighing. There are effects such as reducing the error. The degree of modification of the amine compound is not particularly limited.

The following are examples of the organic amine compound used in the present invention. 1) Aliphatic polyamine (polyalkylene polyamine) or monoamine: ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine,
Tetraethylenepentamine, pentaethylenehexamine, iminobis-propylamine, bis (hexamethylene) triamine, dimethylaminopropylamine, diethylaminopropylamine, aminoethylethanolamine, methyliminobispropylamine, menthanediamine-3, N-aminoethyl Piperazine, 1,3-diaminocyclohexane, isophoronediamine, triethylenediamine, polyvinylamine, stearylamine, laurylamine and the like. 2) Aromatic polyamine or monoamine: m-phenylenediamine, 4,4'-methylenedianiline, benzidine, diaminodiphenyl ether, 4,4'-thiodianiline, dianisidine, 2,4-toluenediamine, diaminodiphenylsulfone, 4,4 '-(O-toluidine), o-phenylenediamine, methylenebis (o-chloroaniline), m-aminobenzylamine, aniline and the like. 3) Aliphatic polyamine or monoamine having an aromatic ring group: metaxylylenediamine, tetrachloroxylenediamine, trimethylaminomethylphenol, benzyldimethylamine, α-methylbenzyldimethylamine and the like. 4) Secondary amine: N-methylpiperazine, piperidine, hydroxyethylpiperazine, pyrrolidine, morpholine and the like. 5) Tertiary amines: tetramethylguanidine, triethanolamine, N, N'-dimethylpiperazine, N-methylmorpholine, hexamethylenetetramine, triethylenediamine, 1-hydroxyethyl-2-heptadecylglyoxalidine, pyridine, Pyrazine, quinoline, etc. 6) Quaternary ammonium salts: diallyldimethylammonium chloride, hexyltrimethylammonium chloride, cyclohexyltrimethylammonium chloride, octyltrimethylammonium bromide, 2
-Ethylhexyltrimethylammonium bromide,
1,3-bis (trimethylammoniomethyl) cyclohexane dichloride, lauryldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, tetradecyldimethylbenzylammonium chloride and the like. Examples of the amines include amines described in JP-A-10-226989.

The nitrogen-containing compound which reacts with the above-mentioned silicic acid condensate used as the first layer in the present invention is preferably water-soluble, but even if it is water-insoluble, it is used after emulsification or dispersion treatment. You can also. Two or more of the above nitrogen-containing compounds may be used as a mixture.

The coating solution of the nitrogen-containing compound which reacts with the silicic acid condensate can be appropriately diluted with water, an organic solvent such as isopropyl alcohol / methanol, or a mixture thereof depending on the type of the nitrogen-containing compound. The coating solution concentration is 0.0
It is about 1 to 20%, preferably about 0.1 to 5%, and the thickness is preferably 0.005 to 5 μm, more preferably 0.01 to 2 μm.

Next, the concentration of the coating liquid containing the silicic acid condensate and the tabular pigment to be the second layer is 0.1 to 20%, preferably about 1 to 10%, and is appropriately selected depending on the coating method. can do. The thickness of the second layer is 0.01 to 5 μm.
Is preferable, and 0.03 to 2 μm is more preferable.
5 to 1 μm is more preferred. If it is less than 0.01 μm, it cannot catch up with the smoothness of the support surface and pinholes are easily generated in the gas barrier film due to unevenness of the support. If it exceeds 5 μm, not only cracks are easily generated but also the gas barrier film falls off. This is unfavorable because it tends to occur economically disadvantageously.

The second aspect of the present invention is that the highly hydrogenated resin used in the third layer is made of polyvinyl alcohol or ethylene-
It is a resin selected from any one of vinyl alcohol copolymers.

The polyvinyl alcohol is, for example, a polymer obtained by hydrolyzing or transesterifying (saponifying) an acetic ester portion of a vinyl acetate polymer (that is, a copolymer of vinyl alcohol and vinyl acetate), trifluoroacetic acid, or the like. Polymers obtained by saponifying vinyl polymers, vinyl formate polymers, vinyl pivalate polymers, t-butyl vinyl ether polymers, trimethylsilyl vinyl ether polymers, etc. (For details of polyvinyl alcohol, see, for example, , "The World of PVA", 1992, Polymer Publishing Association; Nagano et al., "Poval", 1981, Polymer Publishing Association).

"Saponification" in polyvinyl alcohol
Is preferably 70% or more in terms of molar percentage, more preferably 85% or more, and particularly preferably 98% or more, a so-called fully saponified product. The degree of polymerization of polyvinyl alcohol is preferably from 100 to 5,000, more preferably from 200 to 3,000. Furthermore,
The PVA referred to in the present invention may be modified with a small amount of a copolymer monomer as long as the object of the present invention is not hindered.

Modified products of the above-mentioned polyvinyl alcohol are also included in the scope of the present invention. These modified products are, in the production process of polyvinyl alcohol, a vinyl ester, particularly a vinyl acetate monomer, and another unsaturated copolymerizable therewith. It is obtained by copolymerizing with a monomer. As the other unsaturated monomers, for example, ethylene, propylene, α-hexene,
Olefins such as α-octene, unsaturated acids such as (meth) acrylic acid, crotonic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid, and their alkyl esters and alkali salts, vinylsulfonic acid, styrenesulfonic acid Sulfonic acid-containing monomers such as 2-acrylamide-2-methylpropanesulfonic acid and alkali salts thereof,
Dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, trimethyl-2
-(-1- (meth) acrylamide-1,1-dimethylethyl) ammonium chloride, trimethyl-3- (1
-(Meth) acrylamidopropyl) ammonium chloride, 1-vinyl-2-ethylimidazole, other quaternizable cationic monomers, styrene, alkyl vinyl ether, (meth) acrylamide, and others.

The ratio of these copolymer components is not particularly limited, but is 5 to vinyl alcohol units.
0 mol% or less, preferably 30 mol% or less is preferable, and various forms obtained by any method such as random copolymerization, block copolymerization, and graft copolymerization are used as the form of copolymerization. .

Among these copolymers, a block copolymer obtained by copolymerizing a polycarboxylic acid component with a polyvinyl alcohol component is particularly preferably used, and when the polycarboxylic acid component is polymethacrylic acid, Particularly preferred. Further, it is particularly preferable that the block copolymer is an AB block copolymer in which a polyacrylic acid chain is extended at one end of a polyvinyl alcohol chain. Weight ratio (a) / (b) of acrylic acid block component (b)
Is preferably 50/50 to 95/5, and 60 /
In the case of 40 to 90/10, particularly preferable gas barrier properties are completed, and the bonding characteristics with the base material layer are remarkably completed. Further, among other modified forms, one particularly preferred form is a silyl group-modified polyvinyl alcohol resin composed of a saponified vinyl ester polymer modified with at least one compound having a silyl group in the molecule. is there.

The method for obtaining the modified polymer having such a composition is not particularly limited, but a silyl group is added to a vinyl alcohol polymer such as polyvinyl alcohol or modified polyvinyl acetate obtained by a conventional method. Reacting a compound having a silyl group into the polymer, or activating the terminal of polyvinyl alcohol or a modified product thereof, and introducing an unsaturated monomer having a silyl group in the molecule to the terminal of the polymer. Various modification methods such as graft copolymerization of the unsaturated monomer to a vinyl alcohol polymer molecular chain, a copolymer comprising a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule. And saponifying it, or polymerizing a vinyl ester in the presence of a silyl group-containing mercaptan or the like and saponifying it. Introducing silyl groups into Runado end,
Various methods such as are effectively used.

As the modified polyvinyl alcohol-based resin obtained by such various methods, any resin may be used as long as it has a silyl group in the molecule, but the silyl group contained in the molecule is an alkoxyl group or Those having a reactive substituent such as an acyloxyl group and a silanol group which is a hydrolyzate thereof or a salt thereof are preferable,
Among them, a case of a silanol group is particularly preferred.

Compounds having a silyl group in the molecule used for obtaining these modified polyvinyl alcohol resins include trimethylchlorosilane, dimethylchlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluorosilane. Organohalosilanes such as silane, organosilicon esters such as trimethylacetoxysilane and dimethyldiacetoxysilane, organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane,
Examples include organosilanols such as trimethylsilanol and diethylsilanediol, aminoalkylsilanes such as N-amiethyltrimethoxysilane, and organosilicon isocyanates such as trimethylsiliconisocyanate. The degree of modification by these silylating agents can be arbitrarily adjusted depending on the type, amount and reaction conditions of the silylating agent used.

The unsaturated monomer used in the method for saponifying a copolymer of a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule is vinyltrimethoxysilane. Many vinylsilane-based compounds such as vinylalkoxysilane and vinylmethyldimethoxysilane represented by vinyltriethoxysilane, and alkyl- or allyl-substituted vinylalkoxysilane represented by vinyltriisopropoxysilane; Further, polyalkylene glycol-modified vinyl silanes in which a part or all of these alkoxy groups are substituted with a polyalkylene glycol such as polyethylene glycol can be given. Furthermore, 3- (meta)
Acrylamino-propyltrimethoxysilane, 3-
(Meth) acrylamide-alkylsilane represented by (meth) acrylamide-propyltriethoxysilane and the like can also be preferably used.

On the other hand, a method for polymerizing a vinyl ester in the presence of a mercaptan having a silyl group and then saponifying the silyl group to introduce a silyl group into the terminal includes an alkoxysilylalkyl such as 3- (trimethoxysilyl) -propylmercaptan. Mercaptan is preferably used.

The suitability range of the modified polyvinyl alcohol-based resin of the present invention varies depending on the degree of modification, that is, the content of the silyl group, the degree of saponification, etc., but is important for the gas barrier property which is the object of the present invention. It becomes a factor. The content of the silyl group is usually 30 mol% or less, preferably 10 mol% or less, particularly preferably 5 mol% or less, as a monomer containing a silyl group, based on the vinyl alcohol unit in the polymer. Used. Although the lower limit is not particularly limited, the effect is particularly remarkably exhibited when it is 0.1 mol% or more.

The silylation rate indicates the ratio of the silyl groups introduced after the silylation to the amount of hydroxyl groups contained in the polyvinyl alcohol resin before the silylation.

These various polyvinyl alcohol-based resins may of course be used alone. However, as long as the object of the present invention is not impaired, they may be used as copolymers with other copolymerizable monomers or mixed with other monomers. It can be used in combination with other possible resin compounds. Examples of such a resin include polyacrylic acid or esters thereof, a polyester resin,
Polyurethane resins, polyamide resins, epoxy resins, melamine resins, and others can be used.

The ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) used in the present invention is:
EVOH having a vinyl alcohol fraction of 40 mol% or more and 80 mol% or less, more preferably 45 mol% to 75 mol%. Further, these EVOHs may be modified with a small amount of a comonomer as long as the object of the present invention is not hindered.

The above-mentioned modified EVOH is modified to be crosslinked, and preferably modified to be soluble in alcohol. In order to impart such properties, a silyl group is introduced into EVOH.

The introduction of the silyl group can be performed, for example, by using 3-isocyanatopropyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluoroorganohalosilane, trimethylacetoxysilane. The reaction is performed by reacting a reactive silane compound with a hydroxyl group of EVOH like silane.

The introduction of the silyl group, that is, the silylation, must be carried out so that at least EVOH becomes soluble in alcohol. Specifically, it is preferable that the silylation rate is 0.2 mol% or more. The upper limit of the silylation ratio is not particularly limited from the viewpoint of alcohol solubility, but is preferably 5 mol% or less, more preferably 2 mol% or less, from the viewpoint of the arrangement of the inorganic layered compound in the present invention. The silylation rate indicates the ratio of the introduced silyl group after the silylation to the amount of the hydroxyl group contained in the EVOH resin before the silylation.

The above modified silyl group-introduced modified EVOH
Is dissolved in an alcohol-based solvent due to the presence of the introduced silyl group by heating and dissolving with an alcohol or a mixed solvent of alcohol / water. Then, the modified EVOH dissolved in the solvent, on the other hand, a part of the introduced silyl group reacts by a dealcoholization reaction and a dehydration reaction,
Crosslink. The reaction requires the presence of water,
It is preferable to use a mixed solvent of alcohol / water.

A third aspect of the present invention is that the silicic acid condensate used for the gas barrier layer is sodium silicate represented by a general formula M ₂ O.nSiO ₂ (n is a number of 0 or more, M is Na or Li),
It is at least any one selected from lithium silicate. Among alkali metal silicate salts, sodium silicate is preferable because it has a high film-forming property, hardly causes cracks, and is very inexpensive. Lithium silicate has a lithium ion ionic radius smaller than the sodium and potassium ionic radii of sodium silicate and potassium silicate, so that when silica is condensed, lithium ions are easily incorporated into the silicate condensation network. Lithium ions are trapped in the object, and the ions are hard to move. For this reason, when lithium silicate is used as the silicic acid condensate, the water resistance of the gas barrier layer is much higher and more preferable than when sodium silicate or potassium silicate is used. Further, it is more preferable to use a mixture of sodium silicate and lithium silicate since a coating film having particularly excellent film-forming properties and water resistance can be obtained.

A fourth aspect of the present invention is the first aspect including a nitrogen-containing compound.
Is a layer further containing a water resistance improver. The first layer containing the nitrogen-containing compound that reacts with the silicic acid condensate dissolves when the temperature and humidity environment used is severe, and the second and third layers are dissolved.
Layer may peel off from the support in some cases. In such a case, it is preferable to use a water resistance improver in combination. By doing so, the water resistance of the first layer containing the nitrogen-containing compound is improved, and elution under severe temperature and humidity environments can be prevented.

In the present invention, the water resistance improver is primarily an epoxy compound. Epoxy compounds are mono,
It is an epoxy compound containing several epoxy groups such as di and tri. This epoxy compound includes an aliphatic epoxy compound and an aromatic epoxy compound, for example, butylene oxide, octylene oxide, butyl glycidyl ether, styrene oxide, phenyl glycidyl ether, glycidyl methacrylate, allyl glycidyl ether, phenol polyethylene glycol glycidyl ether, Lauryl alcohol polyethylene glycol glycidyl ether and the like.

Further, polyamidoamine-epihalohydrin or formaldehyde condensation reaction product, polyamine-epihalohydrin or formaldehyde condensation reaction product, polyamide polyurea-epihalohydrin or formaldehyde condensation reaction product, polyamine polyurea-
The epihalohydrin or formaldehyde condensation reaction product and the polyamidoamine polyurea-epihalohydrin or formaldehyde condensation reaction product can be used alone or in combination.

The above condensation reaction product contains an amino group in its molecular skeleton and has an epoxy ring or a methylol group in its side chain. Generally, the following components: (i) polyalkylene polyamine, (ii) urea , (Iii) dibasic carboxylic acids, (iv) epihalohydrins or formaldehyde to react (for example, Japanese Patent Publication No. 52-22982, Japanese Patent Publication No. 60-3194).
No. 8, JP-B-61-39435, JP-A-55-127
423).

The mixing ratio of the nitrogen-containing compound to the water resistance improver is from 99.9 / 0.1 to 5/95 by mass, preferably from about 99/1 to 20/80. Since the preferred ratio greatly varies depending on the reactivity of each nitrogen-containing compound and the molar ratio of the nitrogen atom when copolymerized, it is most preferable to use the ratio appropriately ascertained.

Examples of the water-resistant agent added to make the organic layer water-resistant include acids (eg, hydrochloric acid, sulfuric acid, borofluoric acid, acetic acid, glycolic acid, maleic acid, lactic acid, citric acid, tartaric acid, oxalic acid) And the like, metal salts (eg, magnesium chloride, magnesium nitrate, magnesium borofluoride, zinc borofluoride, zinc chloride, zinc nitrate, sodium bisulfate), ammonium chloride, and the like, and these are used alone or in combination.

The fifth aspect of the present invention is to use at least one of polyalkyleneimine and polyalkyleneamine as the nitrogen-containing compound which reacts with the silicic acid condensate. Polyalkyleneimine is in the main chain skeleton of the molecule,
Alternatively, a basic compound containing a nitrogen atom in the branched chain skeleton and having a high nitrogen content and a molecular weight of about 10,000 is known. The polyalkyleneamine is an amine having a primary amine, a secondary amine, and a tertiary amine in a side chain, and has a molecular weight of about 300 to about 50,000. When these have a molecular weight of tens of thousands, they do not readily dissolve themselves, but oligomers are easily dissolved in water, and thus are preferably used in combination with a water resistance improver.

A sixth aspect of the present invention is that the tabular pigment used in the present invention is at least one pigment selected from smectite clay and mica. Each of these pigments has high flatness, and not only prevents the shrinkage of the film due to the condensation reaction of the silicic acid condensate, but also increases the permeation distance of oxygen molecules by the curved effect, thereby increasing the effective film thickness. And particularly preferred.

The gas barrier laminate of the present invention has a temperature of 23 ° C.
Oxygen permeability at 90% RH is 30 cc / m ² · da
It is preferably at most y · atm, more preferably 10 cc / m ² · day · atm. When the oxygen permeability is 30 cc / m ² · day · atm or less, the oxygen permeability is low enough to be practically used as a gas barrier laminate, and 10 cc / m ² · day · a
If it is tm or less, the usable applications are expanded. The oxygen permeability was measured using OX-TRAN / 100 model of MOCON.

In the present invention, in the second layer, a layer of at least one kind of silicic acid condensate selected from an alkali metal silicate and colloidal silica and a layer of a tabular pigment;
In the high hydrogen bonding resin layer which is a layer of the above, a color adjusting agent, a viscosity adjusting agent, an inorganic pigment, an organic pigment (plastic pigment), various curing agents for alkali metal silicate (carbonate, sulfate, hydrochloride, nitrate) Inorganic salts such as phosphates and silicates; mineral acids such as nitric acid, phosphoric acid, hydrochloric acid and sulfuric acid; organic acids such as lactic acid, humic acid and oxalic acid; polyaluminum chloride and aluminum dihydrogen polyphosphate; Phosphoric acid compounds such as sodium hexametaphosphate, metal oxides such as zinc oxide and titanium oxide, and metal hydroxides such as aluminum hydroxide and magnesium hydroxide) can be added as necessary. Further, for example, a compound such as a titanium coupling agent, a silane coupling agent, a melamine coupling agent, an epoxy coupling agent, an isocyanate coupling agent, a copper compound, and a zirconia compound may be added as a crosslinking agent. it can.

Further, a resin may be added to the second layer of the present invention as long as its properties are not impaired. Although the resin used in the present invention is not particularly limited, for example, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), polysaccharide, polyacryl Acids and esters thereof.

Further, the support of the present invention includes an antioxidant, a weather stabilizer, a light stabilizer, an antistatic agent, a pigment, a dye, a plasticizer, a flame retardant, an inorganic filler such as silica, alumina, calcium carbonate, It may contain talc, kaolin, clay, zeolite, mica, carbon black, glass fiber, and the like.

The application of the gas barrier laminate of the present invention is mainly used for packaging, and the food applications include miso, pickles, side dishes, baby food, boiled tsukudani,
Konjac, Chikuwa, Kamaboko, processed fishery products, meatballs, hamburgers, seasoned meat for Genghis Khan, ham, sausage, other processed meat products, green tea, coffee, tea, bonito flakes, oily confectionery such as toro kombu, potato chips, butter peanuts, rice It can be widely used for confectionery, biscuits, cookies, cakes, buns, castella, cheese, butter, cut rice cakes, soups, sauces, ramen and the like. Furthermore, it can be used for a wide range of uses such as pet food, agricultural chemicals, fertilizers, infusion packs, semiconductor packaging, oxidizing chemical packaging, precision material packaging, and other industrial material packaging for medical, electronic, chemical, and mechanical applications.

The gas barrier laminate of the present invention is obtained by applying a coating containing a silicic acid condensate and a plate-like pigment to the surface of the support or the molded product, followed by drying. Coating methods include a direct gravure method, a reverse gravure method, a microgravure method, a roll coating method such as a two roll beat coating method, a bottom feed three reverse coating method, and a doctor knife method, a die coating method, a dip coating method, and a bar coating method. Coating methods include kiss coating, lip coating, blade coating, air knife coating, dipping, and brush coating. In addition, a method such as a coating method in which these are combined may be mentioned, but it is not limited to these methods.

Examples of the drying method include drying with hot air, drying with dry air, drying with infrared rays, drying with microwaves, drying with a gas burner, and drying with a combination of two or more of these methods. It is not limited. The drying temperature is not particularly limited, but is preferably 50 ° C to 300 ° C, more preferably 70 ° C.
C. to 200C, more preferably 90C to 150C. When a thermoplastic resin is used for the support, it is necessary to dry at a temperature lower than its melting point, so that low-temperature drying is desirable, and the drying temperature is preferably 70 ° C to 120 ° C. The second layer is
If the drying temperature is less than 50 ° C., the condensation of silicic acid will be insufficient, and the water resistance and barrier properties will be insufficient. If the temperature exceeds 120 ° C., the strength of the support deteriorates and the color tone changes, which is not preferable.

[0089]

The present invention will be specifically described below with reference to examples. Numerical values indicating the composition, concentration, amount of addition, etc. are numerical values based on the mass of the solid content or the active ingredient.

<Example 1> On a biaxially oriented polypropylene film (OPP) 25 μm having a corona treatment on one side,
Polyethyleneimine (trade name; Epomin P-1000,
An aqueous solution of 30% polyethyleneimine resin was diluted to 1% with isopropyl alcohol, molecular weight 70,000, specific gravity 1.04, amine value 18 (mgeq / g · soli).
d), amine ratio primary / secondary / tertiary = 25/50/25;
Nippon Shokubai Co., Ltd.) was applied so that the film thickness after drying was 0.04 μm, and dried with a hot-air dryer at 80 ° C. for 2 minutes to form an organic first layer. Next, a lithium silicate solution having a molar ratio of 3.5 (trade name: lithium silicate 35, solid content: 23% as Li ₂ O · SiO ₂ , Nippon Chemical Industry Co., Ltd.)
(Manufactured by Coop Chemical Co., Ltd.) and synthetic smectite (trade name: Lucentite SWN, solid content: 91%, manufactured by Corp Chemical Co., Ltd.) dispersed in water using a homomixer (solid content: 2%). ) Was mixed at a solid content ratio of 50/50 to prepare a 5% dispersion. The obtained dispersion was applied using a Mayer bar so that the film thickness after drying was 0.4 μm, and dried at 110 ° C. for 1 minute. Further, 4% polyvinyl alcohol (trade name: NH-26, fully saponified, degree of polymerization: 2600, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was applied thereon so that the film thickness after drying was 0.2 μm. Work, 130
The resultant was dried at a temperature of 2 ° C. for 2 minutes to obtain a gas barrier laminate having a three-layer structure.

Example 2 A biaxially stretched polypropylene film (OPP) having a corona treatment on one side was placed on 25 μm,
Polyamine having a molecular weight of 20,000 (trade name: Polyment NK-1)
00PM, aminoethylated resin, diluted to 2% with methanol, Nippon Shokubai Co., Ltd.)
m and dried with a hot air drier at 80 ° C. for 2 minutes to form an organic first layer. Then, a molar ratio of 3.5
Of montmorillonite (trade name; Kunipia F, solid content: 520 nm) in a lithium silicate salt solution (trade name: lithium silicate 35, solid content: 23% as Li ₂ O.SiO ₂ , manufactured by Nippon Chemical Industry Co., Ltd.) 90%, Kunimine Industry Co., Ltd.
(Manufactured by K.K.) was dispersed in water using a homomixer (solid content: 2%) to prepare a 5% aqueous dispersion obtained by mixing at a solid content ratio of 70/30. The resulting aqueous dispersion was applied using a Meyer bar so that the film thickness after drying was 0.3 μm,
It was dried at 110 ° C. for 1 minute. Further, an ethylene-vinyl alcohol copolymer (trade name: Soarnol 16D, water /
(Isopropyl alcohol = 50/50, 4% concentration, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is applied so that the film thickness after drying is 0.2 μm, and dried at 130 ° C. for 2 minutes to form three layers. A gas barrier laminate having a structure was obtained.

Comparative Example 1 A gas barrier laminate was obtained in the same manner as in Example 1 except that the third layer of polyvinyl alcohol was not provided.

<Comparative Example 2> A laminate was produced in the same manner as in Example 1 except that the first layer made of a nitrogen-containing compound was not provided on the support. The membrane has detached from the support.

Comparative Example 3 One side of a biaxially stretched polypropylene film (OPP) 25 μm was subjected to corona treatment, and the corona treated surface was treated with polyvinyl alcohol (trade name: PVA1).
20, completely saponified type, polymerization degree 2000, manufactured by Kuraray Co., Ltd.) and synthetic mica (trade name: NTS-5, manufactured by Topy Industries, Ltd.) at a solid content ratio of 70/30, and solid content concentration A 1% gas barrier coating was prepared. The obtained gas barrier paint is applied using a Mayer bar so that the film thickness after drying becomes 0.8 μm, and dried at 120 ° C. for 1 minute using a hot air drier to obtain a gas barrier laminate. Was prepared.

<Test Method> 1) Oxygen permeability: 23 ° C./60% RH with the coated surface facing the oxygen detector by JIS-K-7126 B method (isobaric method)
The measurement was performed under the conditions of 23 ° C. and 90% RH (oxygen permeability measuring apparatus: OX-TRAN100, manufactured by MOCON). 2) Flex resistance test: Angle 440 with gelbo flex tester (manufactured by Tester Sangyo Co., Ltd.) with the coated surface inside.
C., 10 strokes at a linear stroke of +63.5 mm, and the oxygen permeability of the sample after the test was measured at 23.degree. C. and 60% RH (JIS-K-7126 B).
Method (isobaric method), oxygen permeability measuring device: OX-TRAN1
00 type, manufactured by MOCON). 3) Efflorescence test: Gas barrier laminate at 40 ° C / 90%
It was left for two weeks in an RH environment, and the haze (haze value) of the coating film before and after being left was compared. Haze was calculated from diffuse transmittance (Td) / total light transmittance (Tt) (reflection / transmittance meter: H
R-100, MURAKAMI COLOR RESERCH LABORATORY
Made). The rise in haze is calculated by (haze after standing) − (haze before standing).
% Was exceeded.

[0096]

[Table 1]

[0097]

According to the present invention, gas barrier properties are excellent,
It is possible to provide a gas-barrier laminate that is useful as various packaging materials, and that is resistant to flexing and preventing the phenomenon of efflorescence.

Claims (6)

[Claims] 1. A gas barrier laminate having a gas barrier layer formed on at least one surface of a support, wherein the gas barrier layer is formed by sequentially laminating the following three layers from the support side. Laminate. (1) A first layer containing a nitrogen-containing compound that reacts with a silicic acid condensate. (2) A second layer containing at least one silicic acid condensate selected from alkali metal silicate or colloidal silica, and a tabular pigment. (3) A third layer containing a high hydrogen bonding resin. 2. The gas barrier laminate according to claim 1, wherein the high hydrogen bonding resin is a resin selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer. 3. The silicic acid condensate has a general formula of M ₂ O.nSiO.
₂ (wherein, n is a number greater than or equal to 0, and M represents Na or Li), and is at least one selected from sodium silicate and lithium silicate. 3. The gas barrier laminate according to any one of 2. 4. The gas barrier laminate according to claim 1, wherein the first layer contains a water resistance improver. 5. The gas barrier laminate according to claim 1, wherein the nitrogen-containing compound is at least one compound selected from polyalkyleneimines and polyalkyleneamines. 6. The gas barrier laminate according to claim 1, wherein the tabular pigment is at least one pigment selected from smectite clay and mica.