JP2003071971A - Gas-barrier laminate and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-barrier laminate holding excellent gas barrier properties even when it passes a long period under the condition of high humidity, preventing a whitening phenomenon and being suitable for a material for packaging. SOLUTION: In the gas-barrier laminate having a gas-barrier layer provided at least on one side of a substrate, the gas-barrier layer contains at least one kind of silicic acid condensate selected from an alkali metal silicate and a colloidal silica, a flat-sheet-like pigment and a neutral salt formed of an alkali metal salt and an acid substance other than a silicic acid.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas barrier laminate suitable for various packaging materials and molding materials.

[0002]

2. Description of the Related Art In a packaging material used for packaging foods and the like, a gas barrier property, particularly a barrier property of oxygen, water vapor, carbon dioxide and aroma (aroma, flavor) is important from the viewpoint of protecting the quality of contents. It is quality. Packaging materials using such barrier materials are confectionery bags,
Skipjack packs, retort pouches, meat packaging such as ham and sausage, seafood packaging, dairy product packaging, miso packaging, tea / coffee packaging, carbon dioxide beverage container, cosmetics, pesticide and pharmaceutical packaging, etc. It is used in many fields. On the other hand, polyolefin resins such as polyethylene and polypropylene, polyethylene terephthalate (P
Polyester resins such as ET) and polyethylene naphthalate (PEN), polyamide resins such as nylon 6 and nylon 66, and thermoplastic resins such as polystyrene and ethylene vinyl acetate copolymer are excellent in strength, heat resistance and transparency. Therefore, it is widely used as a packaging material. However, when using a film made of these thermoplastic resins as a packaging material, the gas barrier property is insufficient,
A method of laminating a thermoplastic resin having a gas barrier property, an aluminum foil, an aluminum vapor deposition film, a silicon vapor deposition film, or the like into a packaging material is generally used.

Thermoplastic resins having a high gas barrier property include polyvinyl alcohol (hereinafter PVA), polyethylene vinyl alcohol (EVOH, saponification product of ethylene-vinyl acetate copolymer), polyalcohol (reduction product of polyketone), polychlorination. Vinylidene (PVDC) and the like can be mentioned, but a high hydrogen bonding resin that exhibits a barrier property by hydrogen bonding due to a hydroxyl group such as PVA or EVOH is a barrier at high humidity (for example, 20 ° C. and 80% RH or more). There is a problem that the sex drops sharply. Also, PVDC
Has excellent barrier properties under high humidity conditions, but shows a large decrease in barrier properties at high temperatures. Moreover, since PVDC is a chlorine compound, it may cause problems such as generation of dioxins when incinerated, and the recent situation is to refrain from using it as a packaging material as much as possible due to heightened awareness of global environmental issues. is there.

As a method of improving the gas barrier property of a high hydrogen-bonding resin under high humidity conditions, a gas barrier layer obtained by adding an inorganic layered compound to the high hydrogen-bonding resin (JP-A-7-251).
No. 489). However, in the gas barrier layer obtained by this technique, the high hydrogen-bonding resin has a hydrophilic polar group, and the polar group hydrogen bonds with water molecules, so that the resin itself is likely to swell. Since oxygen molecules easily pass through the swollen molecular chain, the gas barrier property deteriorates. Therefore, although the inorganic layered compound is added,
Satisfactory gas barrier properties under high humidity conditions cannot be obtained. Further, when the compounding amount of the inorganic layered compound is increased in order to improve the gas barrier property under high humidity conditions, the transparency of the gas barrier layer is reduced and the haze (haze) is decreased.
Becomes larger and can be used only in a limited field as a packaging material.

Further, there is a conventional technique for forming a gas barrier layer with an alkali metal silicate solution. For example, a method of obtaining a gas barrier laminate by applying an aqueous liquid comprising an alkali metal silicate solution and a coupling agent to the surface of a polymer molded article to form a thin film (JP-A-8-238711), A method of mixing a sodium silicate aqueous solution and a lithium silicate aqueous solution to obtain a gas barrier material from this mixture can be mentioned (JP-A-7-18202). The former has an advantage that a gas barrier laminate can be manufactured at low cost without performing an operation such as vapor deposition, but the gas barrier property may still be insufficient, and there is a problem that coating strength and water resistance are poor. Remain. Further, it is difficult to say that the latter gas barrier layer containing an alkali metal silicate as a main component completely solves the problems of insufficient water resistance of the alkali metal silicate coating and the occurrence of cracks.

On the other hand, there is a conventional technique for forming a gas barrier layer by hydrolysis of a metal alkoxide. For example, in Japanese Patent No. 2556940, a composition containing an alkoxysilane, a silane coupling agent and polyvinyl alcohol is polycondensed to form a gas barrier laminate film from a composite polymer whose main component is a linear polymer. The technology is described. However, even with this method, satisfactory results have not been obtained regarding gas barrier properties under high humidity conditions.

Further, JP-A-11-129379 discloses a gas barrier laminate comprising an inorganic layered compound, a resin and a hydrolyzate of a metal alkoxide.
In this method, a hydrolyzate of a metal alkoxide is further added to a paint mainly composed of an inorganic layered compound and a resin. Since the reaction proceeds so as to have a three-dimensional network structure, the gas barrier layer thus formed must be porous, and high barrier properties cannot be expected even if an inorganic layered compound is added.

The present inventors diligently studied a gas barrier layer using a silicic acid condensate. The silicic acid condensate refers to an alkali metal silicate or colloidal silica. The alkali metal silicate is also called water glass, and examples thereof include sodium silicate, lithium silicate, and ammonium silicate. Colloidal silica is typified by colloidal particles obtained by subjecting an alkali metal silicate to dealkalization using an ion exchange resin and then condensing it.

Alkali metal silicates and colloidal silica are ultrafine particles whose primary particles are nanometer or less or nanometer level, and in a solution, there are many monomers, dimers, trimers, octomers and oligomers condensed with them. In addition, these particles have a reactive functional group on the surface, and not only the particles are spread at the time of forming a film, but also a condensation reaction occurs when dried to form a uniform barrier film.

As a result of intensive studies, the inventors of the present invention have combined a silicic acid condensate and a tabular pigment to prevent a gas barrier layer from cracking (see Japanese Patent Application Laid-Open No. 20-58).
No. 01-336507). However, if the silicic acid condensate and the tabular pigment are used alone, the water resistance may be insufficient when they are kept at high temperature and high humidity for a long period of time, and peeling off from the support or cracks may occur. there were.

As a result of further study on this problem, as a result of using a nitrogen-containing compound that reacts with a silicic acid condensate to promote condensation,
A gas barrier laminate having improved water resistance of the gas barrier layer and adhesion to the support was obtained (Japanese Patent Application No. 2000-0678).
No. 58). However, since the film of the silicic acid condensate is inorganic, it has the advantage that it is hard and is not easily scratched. On the other hand, when it is used as a packaging material, it may have insufficient flex resistance depending on the intended use. When using a silicic acid alkali metal salt as a silicic acid condensate, since the silicic acid alkali metal salt is strongly alkaline, it absorbs moisture and carbon dioxide in the air and the coating film turns white (white flower phenomenon), resulting in an appearance. Has the drawback of being impaired.

Therefore, the present inventors provided an overcoat layer containing a high hydrogen-bonding resin on the gas barrier layer containing a silicic acid condensate to impart flexibility, and the white change of the coating film was reduced. Proposed a gas barrier laminate (Japanese Patent Application No. 200
0-220059). However, even in the above gas barrier laminate, the prevention of the white bloom phenomenon is not complete, and the gas barrier property under high humidity conditions is sufficient in a short time, but under a high humidity for a long time (24 It was inadequate after (more than time). As described above, when a gas barrier film containing a silicic acid condensate and a tabular pigment as a main material is used as a packaging material, the gas barrier property is significantly deteriorated when left in a high humidity condition for a long time. The range of use as a material was limited.

[0013]

DISCLOSURE OF THE INVENTION The present invention has a gas barrier property which is excellent even after a long period of time under high humidity conditions, and prevents the white bloom phenomenon, and is suitable as a packaging material. The present invention provides a laminated body.

[0014]

The present invention adopts the following method in order to solve the above problems. That is, the first of the present invention is
In a gas barrier laminate having a gas barrier layer provided on at least one surface of a support, the gas barrier layer is at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, tabular pigments, alkali metal salts and silicic acid. It is a gas barrier laminate including a neutralized salt formed by an acidic substance other than.

The second aspect of the present invention is that the silicic acid condensate has the general formula M
The gas barrier according to the first aspect of the present invention, which is at least one or more selected from sodium silicate, potassium silicate, and lithium silicate represented by ₂ O · nSiO ₂ (n> 0, M = Na, K, Li). It is a laminated body.

A third aspect of the present invention is described in the first and second aspects of the present invention, wherein the neutralizing salt is at least one selected from phosphoric acid compounds, sulfuric acid compounds, carbonic acid compounds, nitric acid compounds and boron compounds. Is a gas barrier laminate.

A fourth aspect of the present invention is the gas barrier laminate according to any one of the first to third aspects of the present invention, in which the gas barrier layer contains a hydrolyzed condensate of a metal alkoxide having an organic functional group.

The fifth aspect of the present invention is the gas barrier laminate according to the first aspect of the present invention, wherein the tabular pigment is at least one selected from the group consisting of smectite clay and mica.

The sixth aspect of the present invention is the gas barrier laminate according to any one of the first to fifth aspects of the present invention, in which an anchor layer containing a nitrogen-containing compound is present between the support and the gas barrier layer.

The seventh aspect of the present invention is the gas barrier laminate according to the sixth aspect of the present invention, wherein the nitrogen-containing compound is at least one selected from polyalkyleneimines and polyalkyleneamines.

The eighth aspect of the present invention is the gas barrier laminate according to any of the sixth to seventh aspects of the present invention, in which the anchor layer contains at least one selected from high hydrogen-bonding resins and water resistance improvers. is there.

The ninth aspect of the present invention is the gas barrier laminate according to any one of the first to eighth aspects of the present invention, wherein an overcoat layer containing a high hydrogen-bonding resin is provided on the gas barrier layer.

The tenth aspect of the present invention comprises at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, a tabular pigment, an ammonium salt of an inorganic acid, an ammonium salt of an organic acid, urea and boron oxide. A method for producing a gas barrier laminate, which comprises forming a gas barrier layer by coating a support with a gas barrier coating material containing at least one acidic substance selected from the group consisting of:

The eleventh aspect of the present invention is that the acidic substance in the gas barrier coating composition is 10 to 500 relative to the alkali metal ion.
The method for producing a gas-barrier laminate according to the tenth aspect of the present invention, wherein the gas barrier laminate is contained in an amount of 1 mol%.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The gas barrier layer in the present invention contains at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, a tabular pigment, and a neutralizing salt of an alkali metal salt and an acidic substance other than silicic acid.

Of the silicic acid condensates, the silicic acid alkali metal salt is a compound represented by M ₂ O.nSiO ₂ (M is an alkali metal, n> 0). It is usually handled as a concentrated aqueous solution. The alkali metal M is lithium, sodium, potassium or the like. Further, in the present invention, cationic ions such as ammonium are also included in the category of M. n is also called a molar ratio, and a range of about 0.5 to 10 is suitable. When the molar ratio is less than 0.5, the film-forming ability due to condensation of silicic acid is lowered, and the content of the alkali metal salt is too large, so that the water resistance and the moisture resistance are often lowered, and the white flower phenomenon easily occurs. Further, when the molar ratio exceeds 10, there is a possibility that defects such as cracks may occur on the coated surface.

A high molar ratio of alkali metal silicate having a molar ratio of more than 10 is not commercially available in general, however,
It is possible to prepare by a method of adding various alkali metal hydroxides to amorphous silica or colloidal silica to dissolve it, or to a commercially available alkali metal silicate salt, by dissolving amorphous silica or colloidal silica, The alkali metal silicate thus prepared can also be used in the present invention.
If a high molar ratio alkali metal silicate is used, a very thin tabular pigment having a specific shape may be used, or
By forming an ultrathin film having a thickness of 5 μm or less, if the shrinkage in the thickness direction of the thin film is made approximately the same as the shrinkage of the surface, cracks are less likely to occur.

Among the silicic acid condensates, colloidal silica can be obtained by neutralizing sodium silicate with an inorganic acid or hydrolyzing 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 heated to generate nuclei of colloidal silica, and the cation exchange resin layer is passed through the solution. It is obtained by slowly dropping the prepared sodium silicate solution. If the dropping speed is increased rapidly, the condensation will proceed rapidly and aggregation will occur, resulting in a porous structure, which is not preferable. By slowly dropping, the monomers are sequentially deposited on the silanol groups on the surface of the nucleus, and the particles grow. By appropriately adjusting the pH and slowing the dropping rate, colloidal silica can be grown to an arbitrary size of several nm to several μm. The particle diameter of the colloidal silica used in the present invention is preferably in the range of several nm to several hundred nm. In addition, the packing rate can be increased by using colloidal silica having different particle diameters in combination.

Colloidal silica may be inferior in film forming property and gas barrier property as compared with alkali metal silicate. In that case, the film-forming property and the gas barrier property can be improved by adding an alkali metal salt to the colloidal silica to cleave the siloxane bond on the surface of the colloidal silica.

As the silicic acid condensate used in the present invention, alkali metal silicates and colloidal silica are more preferably alkali metal silicates from the viewpoint of gas barrier properties. As the alkali metal silicate, when sodium silicate in which the alkali metal is sodium, a molar ratio of 0.
5 sodium orthosilicate (Na ₂ O · 1 / 2SiO ₂
Alternatively, Na ₄ SiO ₄ ) and sodium sesquisilicate (3Na ₂ O · 2SiO ₂ or Na ₆ ) having a molar ratio of 0.67.
Si ₂ O ₇ ), sodium metasilicate (Na ₂
O.SiO ₂ or Na ₂ SiO ₃ ), sodium disilicate (Na ₂ O.2SiO ₂ or Na ₂ ) with a molar ratio of ₂
Si ₂ O ₅ ), sodium tetrasilicate with a molar ratio of 4 (Na ₂ O
・ 4SiO ₂ or Na ₂ Si ₄ O ₉ , other name: sodium silicate No. 4), etc., and Japanese Industrial Standard JIS-K
Sodium silicate No. 1 (molar ratio 2) specified by -1408,
There are No. 2 (molar ratio 2.5), No. 3 (molar ratio 3), 1 type of sodium metasilicate and 2 types of sodium metasilicate.

[0031] Although even the composition in potassium silicate is an alkali metal potassium there is a variety, potassium metasilicate _(K 2 O · _SiO 2) as an example, potassium tetraborate silicate _{(K 2 O · 4SiO 2 ·} H 2 O, also known as potassium hydrogen disilicate). Lithium silicate in which the alkali metal is lithium is lithium orthosilicate (Li ₂ O.1 /
2SiO ₂ ), lithium metasilicate (Li ₂ O.Si
O ₂ ), 3.5 lithium silicate, 7.5 lithium silicate (L
i ₂ O · 7.5SiO ₂ ).

Further, for example, an ammonium salt such as ammonium silicate having tetramethylammonium ion as a counter ion is also included in the category of alkali metal silicate in the present invention.

These alkali metal silicates have different condensation degrees and particle sizes depending on the molar ratio. The size cannot be clearly determined because the solubility in the liquid increases as the molar ratio decreases, but by analogy with the dynamic light scattering method, most of them are several nm or less, and the gas barrier layer Can be packed as tightly.

Two or more kinds of these alkali metal silicates may be mixed and used, or two or more kinds of the alkali metal silicate and colloidal silica may be mixed and used. In addition, an alkali metal salt may be added for use in order to improve the film forming property.

The combined use of the silicic acid condensate and the tabular pigment as described above can improve the resistance to volume shrinkage (prevention of cracks). Such a concept is in the field of plastic molding. For example, a method has been adopted in which glass fibers are kneaded into a plastic to prevent the occurrence of crazes that would be destroyed when an impact is applied to the reinforced plastic. Also in the present invention, by mixing the tabular 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. It is difficult to obtain such an effect with a spherical pigment typified by calcium carbonate, and it is an effect peculiar to a tabular pigment. Further, since the tabular pigment has a large specific surface area and its surface is hydrophilic, the silanol group 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.

Further, the tabular pigment has not only an effect of preventing the generation of cracks due to shrinkage accompanying the condensation of the silicic acid condensate, but also a unique effect on the gas barrier property. The tabular pigment is a pigment having a generally tabularity, and has a major axis to thickness ratio (aspect ratio) of 5 or more. In the present invention, a silicic acid condensate and a tabular pigment are mixed in the gas barrier layer, and the tabular pigment is spread in a fish scale shape in the gas barrier layer to prevent gas from entering. The tabular pigment is an inorganic substance having crystallinity, and gas molecules do not permeate from the plane direction to the thickness direction.
In the present invention, such a tabular pigment is spread, by stacking the tabular pigment in multiple layers in the thickness direction of the layer, gas molecules to be permeated to bypass the tabular pigment and permeate, a so-called curved path effect. To be demonstrated. Therefore, it is possible to obtain a gas barrier property which is several times superior to the case where a pigment having a shape close to a sphere, such as calcium carbonate, which is a general-purpose pigment, is used.

Such a tabular pigment is preferably an inorganic layered compound in which unit crystal layers are stacked on each other to have a layered structure. "Layered compound" is a compound or substance having a layered structure, and "layered structure" means that the planes in which atoms are strongly bound by covalent bonds or the like and are densely arranged have weak bonding forces such as van der Waals force. It is a pigment with a high flatness, which is a structure in which they are stacked in parallel and which is bound by ions.

The first tabular pigment used in the present invention is
Include phyllosilicate minerals. Those belonging to the phyllosilicate mineral are plate-like or flaky and have a clear cleavage property, and they are mica, pyrophyllite, talc,
There are chlorite, septe chlorite, serpentine, stilpnomelene, and clay minerals. Among these, minerals that produce large particles when produced and have a large amount of production, for example, mica and talc are preferable. Mica includes muscovite, muscovite, sericite, phlogopite, biotite, fluorophlogopite (artificial mica), and red mica.
Examples include soda mica, vanadine mica, illite, chimica, paragonite, and brittle mica. Of course, synthetic products such as synthetic mica, which is 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 tabular crystals, but if one crystal is taken, the tabular portion is present, but the whole is granular. However, among kaolins, derami kaolin or the like, which is intentionally peeled off the crystal layer and cut into a flat plate, can be used in the present invention.
When using deramikaolin or the like as a pigment, it may be necessary to reduce the particle size of the pigment used for the gas barrier layer to correspond to the film thickness, and pulverize these pigments with a ball mill, sand grinder, covol mill, jet mill, etc. It is necessary to grind and classify with a machine to obtain the desired size.

The second of the tabular pigments used in the present invention is also effective as a so-called inorganic layered compound having a stacked structure and high tabularity bonded by ions. Specific examples of the inorganic layered compound include graphite, phosphate derivative type compounds (zirconium phosphate type compounds), and chalcogen compounds [dichalcogen compounds represented by the formula MX2. Here, M is an element of group IV (Ti, Zr, Hf), group V (V, Nb, Ta) or group VI (Mo, W),
X represents chalcogen (S, Se, Te). ] Is mentioned.

As the third tabular pigment used in the present invention,
Clay minerals such as the smectite group and the vermiculite group can be mentioned. More specifically, mention may be made of dickite, nacrite, smectite, halloysite, antigorite, chrysotile, pyrophyllite, tetrasilylic mica, sodium teniolite, margarite, vermiculite, xanthophyllite, chlorite, and the like. it can. Further, it is a layered polysilicate,
It can also include kanemite, macatite, islayite, macadiite, kenyaite and the like.

Of these, smectite clay is particularly preferable. The smectite viscosity is composed of crystals having a three-layer structure, and montmorillonite, beidellite, nontrolite, saponite, iron saponite, hectorite, sauconite, stipunsite, hectite and the like are known. Bentonite and acid clay, which are minerals containing montmorillonite as the main component and other components, also fall into the category of smectite clay.

These smectite clays are fine powders of pale yellow or white and have a size of several nm to several μm.
Then, it expands in water and makes a unique colloid 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 water between the flakes.

In general, smectite clay easily forms a colloidal dispersion, that is, a sol, when dispersed in water, but as the concentration increases, it tends to form a gel and exhibits a remarkable thixotropic property. Therefore, it is difficult to prepare a high-concentration smectite clay dispersion. In such a case, it is preferable to add a deflocculating agent because a stable fluid dispersion (sol) is formed and the viscosity of the coating composition is lowered. Examples of the deflocculant include polyvalent phosphates such as hexametaphosphate and polyphosphate (sodium pyrophosphate, etc.).
In particular, sodium pyrophosphate is preferable because of its excellent performance / price ratio.

The particle size of the tabular pigment is 10 nm to 5 μm.
Is preferred, and more preferably 10 nm.
To about 1 μm. When the thickness is less than 10 nm, the flatness does not work effectively, it is difficult to arrange the layers parallel to the support during the drying of the coating layer, and it is difficult to show the 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 deteriorated, which is not preferable.

The tabular compound usable in the present invention is not particularly limited as long as it has a particle size of 10 nm to 5 μm, but from the viewpoint of transparency of the gas barrier laminate, the particle size is 1 μm or less. Is preferred. Furthermore, when the gas barrier laminate is a film and is used for applications where transparency is particularly important (for example, food applications), the particle size is more preferably 0.5 μm or less. Further, this 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
It is preferably within the range of 0%. Such transparency can be obtained, for example, by using a commercially available spectrophotometer (Shimadzu Autograph Spectrophotometer U
V-3100PC type: manufactured by Shimadzu Corporation) can be preferably used for measurement.

The tabular pigment preferably has an aspect ratio of 5 or more obtained by dividing the average particle diameter by the thickness, and more preferably 20 or more from the viewpoint of gas barrier. When the aspect ratio is less than 20, the curved path effect may be small and the gas barrier property may be insufficiently expressed depending on the application. On the other hand, it is technically difficult to obtain a tabular pigment having an aspect ratio of more than 5000, and it is economically expensive. From the viewpoint of ease of manufacturing, the aspect ratio is preferably 5000 or less. To measure the particle size of such a tabular pigment, it is also possible to use a light scattering measuring device, but in the present invention, the average particle by direct observation using a transmission electron microscope or a scanning electron microscope. The diameter was calculated. For the aspect, a rod-shaped object other than scales in the field of view of the electron microscope was searched for and the thickness was determined.

The ratio of the silicic acid condensate to the pigment is 99/1 to 1/99 by mass. In the case of a tabular pigment, smectite clay such as montmorillonite can easily form a film because of its tabularity and surface charge. Of course, the strength of the coating is weak and the water resistance is low, so it is necessary to reinforce with a silicic acid condensate. On the other hand, when the silicic acid condensate is used alone, the coating film is likely to be cracked due to the condensation, but by adding the tabular pigment, the generation of cracks can be significantly reduced. As described above, the silicic acid condensate and the tabular pigment mutually function to compensate for their defects. Therefore, the ratio of the silicic acid condensate to the tabular pigment can be in a wide range as described above. The mass ratio of the silicic acid condensate to the tabular pigment is preferably about 99/1 to 10/90, more preferably 99/2 to 20/80, and even more preferably 99/3 to 30/70. If the ratio of the tabular pigment is less than 1% by mass, the effect of preventing cracks becomes small. If the ratio of the tabular pigment exceeds 90% by mass, the gas barrier property will be deteriorated.

The present inventors hypothesized the cause of the deterioration over time of the gas barrier property of a gas barrier layer containing a silicic acid condensate selected from alkali metal silicates or colloidal silica under high humidity conditions. That is, under high humidity, the alkali metal ions contained in the gas barrier layer gradually adsorb and absorb water, whereby the aqueous solution of alkali metal ions moves through the gas barrier layer and gradually condenses silicic acid or colloidal silica. Siloxane bond (Si-O
-Si bond) is cleaved. This cleavage has little effect on gas barrier properties, at the very least. However, the number of cleavage increases with time. Cleavage of a siloxane bond means that one water molecule causes a hydrolysis reaction with a siloxane bond to generate two silanol groups (—SiOH). Further, it is known that the hydrolysis reaction of the siloxane bond is accelerated by the presence of alkali metal ions. The silanol group generated by the cleavage adsorbs water under high humidity conditions.

As described above, due to the presence of the alkali metal ion, water is first adsorbed, the adsorbed water cleaves the siloxane bond, and the silanol group generated by the cleavage is
It also absorbs water. It is considered that by repeating this, cracks are generated in the coating film, and excessive moisture is absorbed by the gas barrier layer containing the silicic acid condensate or colloidal silica, and the gas barrier property is deteriorated.

When the gas barrier layer contains an alkali metal ion, the silanol groups around the ion are not sufficiently condensed during coating and drying of the gas barrier layer,
A silanol group surrounds the alkali metal salt. Therefore, when left for a long time under high humidity conditions, the alkali gradually adsorbs water. The gas barrier property is not affected at the initial stage of adsorption, but when the amount of adsorbed water increases with time, the siloxane bond is cleaved or the coating film is cracked as described above, and the gas barrier property is deteriorated. Will end up.

When the gas barrier laminate as described above is left under high humidity conditions such as 40 ° C. and 90%,
The alkali metal in the gas barrier layer reacts with carbon dioxide in the air to form an alkali metal carbonate salt. The coating changes to white due to the formation of this alkali metal carbonate (white flower)
Or the gas barrier property is greatly reduced. This white flower and the deterioration of the gas barrier property due to the white flower are promoted under higher humidity conditions. When the humidity is high, moisture is adsorbed on the coating film in the gas barrier layer. The adsorption of water is mainly due to alkali metal salts and silanol groups. When the amount of adsorbed water becomes large, the coating film may be cracked, or continuous defects may be generated in the coating film due to the adsorption of water, so that water, oxygen, or the like may permeate.

The mechanism of the white flower phenomenon will be explained in more detail as follows. Carbon dioxide dissolves in the adsorbed water. Carbon dioxide dissolved in water reacts with the alkali metal salt in the film to become an alkali metal carbonate. For example, among the alkali metal carbonates, lithium carbonate has low solubility in water, and therefore most of it grows as crystals. When crystals grow beyond the size of the wavelength of visible light and the number of crystals increases, diffuse reflection of visible light causes the film to appear white. In addition, highly water-soluble alkali metal carbonates such as sodium carbonate and potassium carbonate dissolve in water at high humidity and the white metal phenomenon does not appear visibly, but under low humidity conditions. When exposed to, the water evaporates and alkali metal carbonate crystals and powders are produced, which appear white. Further, the alkali metal ions in the gas barrier layer bleed out (precipitate) on the surface when the water content in the gas barrier layer increases. The deposited alkali metal ions react with carbon dioxide in the air to form an alkali metal carbonate. If this reaction continues, the film may appear white or the alkali metal carbonate powder may drop off the surface. Further, when a minute crack is formed in the coating film due to moisture absorption, moisture and carbon dioxide enter from the cross section of the crack to promote white flower, or alkali metal ions are deposited on the cross section,
White flowers are generated there. When such white fluff occurs, the gas barrier property also deteriorates significantly. Further, the adsorbed water facilitates the cleavage (hydrolysis reaction) of the siloxane bond in which the silanol groups are condensed. The presence of alkali metal ions promotes the cleavage of the siloxane bond.
When the siloxane bond is cleaved to generate a silanol group, it becomes easier to adsorb water. The larger the amount of water adsorbed, the more likely it is to react with carbon dioxide in the air. As described above, the gas barrier layer made of an alkali metal silicate has drawbacks that a white swell phenomenon occurs due to adsorption of water and the gas barrier property is deteriorated.

Accordingly, the present inventors prevent alkali metal ions in the gas barrier layer from being neutralized with an acidic substance other than silanol to prevent white sinter and prevent deterioration of the gas barrier property under high humidity conditions. I succeeded in doing so. That is, by using an alkali metal ion as a neutralizing salt, the adsorption of water by the alkali metal salt and the cleavage of the siloxane bond are prevented, and the deterioration of the gas barrier property is prevented.

In the present invention, the acidic substance having an alkali metal ion as a neutralizing salt is not particularly limited as long as it is an acidic substance other than silicic acid. Specifically, inorganic acid compounds such as phosphoric acid, carbonic acid, hydrochloric acid, nitric acid, sulfuric acid, acetic acid, benzoic acid, formic acid,
Organic acids such as tartaric acid, maleic acid, malonic acid, phthalic acid and citric acid, boron oxide, ammonium tetraborate, sodium tetraborate, boric acid, boron compounds such as anhydrous boric acid, metal oxides such as titanium and zirconium And so on. These acidic substances are present in the gas barrier layer in the form of a neutralized salt partially or completely neutralized with the alkali metal ions in the coating film. For example, as an example of a neutralized salt of lithium ion as the alkali metal ion and the above acidic substance, trilithium phosphate, lithium dihydrogen phosphate, lithium hydrogen phosphate, lithium carbonate, lithium sulfate, lithium borate salt, etc. There is. When sodium ion and potassium ion are present as alkali metal ions, they are present in the form of sodium salt and potassium salt, respectively. When an ammonium silicate salt is used instead of the alkali metal silicate salt, it becomes an ammonium salt. Also,
A neutralizing salt with an alkali (for example, calcium or magnesium) other than an alkali metal salt such as an alkaline earth metal may be present.

Among the above-mentioned neutralized salts, considering the stability of the gas barrier layer and the water resistance, alkali metal phosphate, alkali metal carbonate, alkali metal sulfate, alkali metal nitrate, alkali metal borate, etc. Is preferred. Among these, alkali metal phosphates, alkali metal carbonates, and borate alkali metal salts are particularly preferable. These neutralized salts are particularly preferable in terms of water resistance.

In order to improve the flexibility of the gas barrier coating, the gas barrier coating may contain a hydrolyzed condensate of a metal alkoxide having an organic functional group. The hydrolysis-condensation product of a metal alkoxide having an organic functional group can be obtained by hydrolyzing a metal alkoxide having an organic functional group with a metal compound such as an organoalkoxysilane, an organotitanate, an organoaluminium union, or a zirconium compound. Here, the metal alkoxide also includes a metal alkylate (an esterified product of a metal and an alkyl group). The hydrolyzed metal alkoxide having an organic functional group causes a condensation reaction with the alkali silicate or the tabular pigment in the paint, or the metal alkoxides cause a condensation reaction. This hydrolysis-condensation reaction also occurs in the coating material, but after coating the coating material on the support and then heating and drying, more condensation occurs. The metal alkoxide having an organic functional group is surrounded by the tabular pigment and the alkali silicate in the gas barrier coating film, and the organic functional group exists in an isolated form inside the gas barrier layer. Therefore, in the vicinity of the organic functional group, condensation of alkali silicate does not proceed and it takes a form in which voids are formed at the molecular level. Therefore, it gives flexibility to the coating film. Since the voids are at the molecular level, the adverse effect on the gas barrier is extremely small. Further, when the organic functional group is a reactive functional group such as epoxy, silanol and epoxy react with each other to improve not only flexibility but also water resistance.

The organoalkoxysilane compound used in the present invention has a hydrophilic portion containing a Si atom, and is, for example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloro. Propylmethyldimethoxysilane, γ-
Glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-mercapto Examples include propyltrimethoxysilane, methyltrimethoxysilane phenyltriethoxysilane, γ-fluoropropyltrimethoxysilane, and N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane. In general, these organoalkoxysilane compounds are often used as a silane coupling agent. Among these organoalkoxysilanes, a silane coupling agent having an epoxy group is preferable in terms of a moisture resistant gas barrier. Also, a relatively compact organic functional group such as a methyl or vinyl group is preferable in terms of flexibility.

The organoalkoxy metal compound used in the present invention contains a polyvalent metal atom (for example, Ti, Al, etc.) in its hydrophilic portion, and is, for example, isopropyltriisostearoyl titanate or isopropyltrioctano. Includes titanate compounds such as iltitanol, isopropylisostearoyl diacrylic titanate, isopropyltricumylphenyl titanate, and isopropyltri (N-amidoethylaminoethyl) titanate, and aluminum compounds such as acetoalkoxyaluminum diisopropylate.

The metal alkoxide having an organic functional group is
In its molecular structure, it contains Si, Ti, Zr or Al atoms and has a high reactivity or affinity for inorganic substances (SiOH, TiO, ZrOH, AlOH).
And a metallic hydroxyl group = highly hydrophilic) and an organic moiety having high reactivity or affinity for an organic compound. The metal alkoxide having an organic functional group is preferably 1 to 100 parts by mass, more preferably 2 to 75 parts by mass, when the total amount of alkali metal silicate, colloidal silica, and tabular pigment is 100 parts by mass. It is more preferably 5 to 50 parts by mass. When the amount of the metal alkoxide having an organic functional group is less than 1 part by mass, the effect of improving flexibility by the metal alkoxide having an organic functional group may be insufficient, and when it exceeds 100 parts by mass, The gas barrier property may be deteriorated.

The thickness of the gas barrier layer is not particularly limited, but 1 nm to 5 μm is preferable. Gas barrier layer is 1n
When it is less than m, the gas barrier property is deteriorated. 5 μm
If the thickness becomes thicker, the effect of gas barrier property will reach a ceiling, which is uneconomical. The more preferable range of the gas barrier layer is 10
nm to 1 μm, and 50 nm to 500 nm is a more preferable range.

The support that can be used in the present invention can be appropriately selected from synthetic resin films, sheets and molded products. Specific examples of the synthetic resin include polyethylene, polypropylene, polyisoprene, polyolefin resin such as polyolefin having an alicyclic structure, polyethylene terephthalate, polyethylene naphthalate, polysuccinic acid ester, polylactic acid ester, polyester resin such as polybutyric acid ester, Examples include polyamide resins such as nylon 6 and nylon 66, acrylic resins such as polymethylmethacrylate, ethylene vinyl acetate copolymer, polyvinyl alcohol, ethylene vinyl alcohol, polystyrene, and polysulfane. Further, a film, a sheet, a molded body or the like in which these resins are laminated by an arbitrary method can also be used. Among these resins, films and sheets of polypropylene, polyethylene terephthalate, nylon 66, etc. are preferably used. Further, as the film, a uniaxially stretched film or a biaxially stretched film can be used.

The above-mentioned support includes an antioxidant, a weather resistance 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, talc. , Kaolin, clay, zeolite, mica, carbon black, glass fiber and the like may be contained.

When the gas barrier layer is laminated on these synthetic resin films or the like, it may be directly laminated on the synthetic resin film, or the synthetic resin film may be surface-treated and used to improve the adhesion. As the method for activating the synthetic resin surface, corona discharge treatment, plasma discharge treatment, chlorinated acid solution treatment, fuming sulfuric acid treatment, sulfuric acid solution treatment, etc. are applied to the surface of the synthetic resin film such as a hydroxyl group, a carbonyl group, an ester group, A hydrophilic component such as a carboxylic acid group, an ether bond, an amino group, an imino group, an amide group, a sulfuric acid group or an amide group can be introduced. Applying a gas barrier coating to the surface of a synthetic resin film or the like treated by such a method has the effects of preventing cissing and spotting and improving the adhesion between the gas barrier layer and the substrate.

When sufficient adhesion cannot be obtained only by such surface treatment (for example, when the base material is a polyolefin resin), an anchor layer is provided on the surface of the base material or the surface-treated base material is further coated. An anchor layer can be provided.
The nitrogen-containing compound firmly adheres to the hydrophilic polar group on the surface of the support by hydrogen bond. Especially when the polar group on the surface of the support is anionic, the nitrogen-containing compound has a cationic property, so that the anionic polar group on the surface of the support and the cationic group of the nitrogen-containing compound are strongly ionic-bonded, and the gas barrier layer is further formed. Since the anionic silicic acid condensate and the anionic tabular pigment contained in (3) firmly adhere to each other by the ionic bond and the dehydration condensation reaction, the adhesion between the support and the gas barrier layer is significantly improved. Further, it is preferable that the anchor layer containing the nitrogen-containing compound and the gas barrier layer containing the silicic acid condensate are mixed to have a graded structure in which the concentration continuously changes. When the nitrogen-containing compound is an organic compound, the organic / inorganic composition has a graded structure, so that not only the improvement of the adhesion of the organic layer to the support and the gas barrier property of the inorganic layer are compatible, but also the water resistance. It also has some resistance to stress and strain. (Japanese Patent Application No. 2000-067858).

Examples of the nitrogen-containing compound used in the anchor layer of the present invention include cationic organic compounds. A silicic acid condensate such as an alkali metal silicate has both silanol groups and dissociated silanol ions in the alkaline region, and these functional groups condense to form a siloxane bond. 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 the silicic acid condensate,
It has been found that the hydroxide ion generated by the cationic organic compound accelerates the condensation reaction of the silicic acid condensate. By way of an example a case where the cationic organic compound is a polyamine, a silanol ions and polyamine cationic ion reaction silicate condensate ^{(~SiO - ... N + ~)} ~
SiO ^- HN ⁺ ~ or covalent bond (~SiO ^- N~) ~
SiON causes gelation. On the other hand, it is considered that OH ⁻ generated by the action of the amine promotes the condensation of silanol groups of the silicic acid condensate to generate new siloxane bonds and expand the siloxane bond network.

Typical of these nitrogen-containing compounds are those called imine compounds and amine compounds. Of these, polyalkyleneimine is a typical example of the imine compound, and polyethyleneimine, an alkyl or cyclopentyl-modified polyethyleneimine, an imine adduct of ethyleneurea, an ethyleneimine adduct of poly (ethyleneimine-urea) and a polyaminepolyamide, or There is a polyimine compound selected from the group consisting of these alkyl modified products, alkenyl modified products, benzyl modified products, or aliphatic cyclic hydrocarbon modified products, polyamide imides, and polyimide varnishes.

As the amine compound, there is polyalkylene polyamine. For example polyethylene polyamine,
Compounds such as ethylenediamine, diethylenetriamine and triethylenetetramine. Further, as those showing similar effects, polyamides such as compounds such as polyethylene imide adducts of polyamides, hydrazine compounds,
Epichlorohydrin adduct of polyamine polyamide (water-soluble and cationic thermosetting resin obtained by reacting polyamide with epichlorohydrin from saturated dibasic carboxylic acid having 3 to 10 carbon atoms and polyalkylene polyamine), etc. The polyamine amide compound, the quaternary nitrogen-containing acrylic polymer, the quaternary nitrogen-containing benzyl polymer, the urethane, the compound having a carboxylic acid amine group, the methylolated melamine, the cationic polyurethane, and the like nitrogen-containing quaternary salt compounds. Further, cationic resins such as cation-modified polyurethane resin, polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer, and tertiary nitrogen-containing acrylic resin can be mentioned (for cationic resin, JP-A-8-90898, JP-A-8-90898). 63-1
No. 62275, JP-A No. 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 polyalkyleneimines used in the present invention are preferably polyethyleneimine and polypropyleneimine, and particularly preferably polyethyleneimine. These polyalkyleneimines may be used alone or in the form of 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, it may be either an organic monoamine or an organic polyamine. Further, the organic amine compound includes a compound having a heterofunctional group other than an amino group, such as an epoxy group, a hydroxyl group, a carboxylic acid group or a nitrile group.

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

For the modification as described above, 1) the toxicity of the amine compound such as irritating odor and skin irritation is reduced, 2) the viscosity of the amine compound is reduced, and 3) the molecular weight is increased to be weighed. There are effects such as reducing the error. The degree of modification of the amine compound is not particularly limited.

Examples of the organic amine compound used in the present invention are as follows. 1) Aliphatic polyamine (polyalkylene polyamine) or monoamine: ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine,
Tetraethylene pentamine, pentaethylene hexamine, 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 salt: diallyldimethylammonium chloride, hexyltrimethylammonium chloride, cyclohexyltrimethylammonium chloride, octyltrimethylammonium bromide, 2
-Ethylhexyl trimethyl ammonium bromide,
1,3-bis (trimethylammoniomethyl) cyclohexanedichloride, lauryldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, tetradecyldimethylbenzylammonium chloride and the like. Further, examples of the amines include amines described in JP-A-10-226989.

The nitrogen-containing compound that reacts with the silicic acid condensate as described above used as the anchor layer in the present invention is preferably water-soluble, but even if it is water-insoluble, it should be emulsified or dispersed for use. Can also You may use the said nitrogen-containing compound in mixture of 2 or more types.

In the present invention, it is possible to further improve the water resistance by adding at least one selected from a high hydrogen bonding resin and a water resistance improver to the anchor layer containing the nitrogen-containing compound as described above. is there.

In the present invention, the water resistance improver is firstly 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, Examples include lauryl alcohol polyethylene glycol glycidyl ether.

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-epihalohydrin or formaldehyde condensation reaction product, and polyamidoamine polyurea-epihalohydrin or formaldehyde condensation reaction product, alone or in combination. Can also be used.

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, and generally has the following components: (i) polyalkylene polyamine and (ii) urea. (Iii) dibasic carboxylic acids, (iv) epihalohydrins or formaldehyde can be reacted to synthesize (for example,
Japanese Patent Publication No. 52-22928, Japanese Patent Publication No. 60-31948
Japanese Patent Publication No. 61-39435, Japanese Patent Laid-Open No. 55-1274.
23).

Other water-proofing agents include acids (for example, hydrochloric acid, sulfuric acid, borofluoric acid, acetic acid, glycolic acid, maleic acid, lactic acid, citric acid, tartaric acid, oxalic acid, etc.), metal salts (for example, chloride, etc.). There are magnesium, 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 coating liquid of the nitrogen-containing compound used in the anchor layer may 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. Coating solution concentration is 0.01-2
0%, preferably 0.1 to 5%, and the film thickness is 0.
005 to 5 μm is preferable, and 0.01 to 2 μm is more preferable.

The compounding ratio of the nitrogen-containing compound and the water resistance improver is 99.9 / 0.1 to 5/95 by mass ratio, preferably about 99/1 to 20/80. The preferred ratio varies greatly depending on the reactivity of each nitrogen-containing compound and the molar ratio of nitrogen atoms in the case of copolymerization.

The highly hydrogen-bonding resin used in the anchor layer together with the nitrogen-containing compound in the present invention is a functional group capable of hydrogen bonding such as a hydroxyl group, a carboxylic acid group, a carbonyl group, an amino group or an amide group in the resin. Refers to a resin having Such a functional group is preferably contained in the resin in an amount of 1% by mass or more. Examples of the high hydrogen bond resin include polyvinyl alcohol (completely saponified and partially saponified), ethylene vinyl alcohol copolymer, polycarboxylic acid, olefin-unsaturated carboxylic acid copolymer, polyvinylamine, polyketone, polyacrylamide, Examples thereof include polyacrylonitrile. Among these, polyvinyl alcohol (hereinafter PVA) and ethylene vinyl alcohol (hereinafter EVOH) are preferable in terms of barrier properties. When PVA is used for the anchor layer, there is an advantage that the anchor layer has excellent compatibility with a nitrogen-containing compound such as polyethyleneimine. When the gas barrier layer contains a substance that reacts with PVA such as boric acid,
There is also an effect that the PVA in the anchor layer reacts with the barrier layer to make the anchor layer water resistant. When PVA is used for the overcoat layer, the PVA layer of the overcoat not only fills cracks and pinholes in the barrier layer, but also plays a role of protecting the gas barrier layer and is excellent in flexibility and flexibility. Can provide the body.

PVA is, for example, a polymer obtained by hydrolyzing or transesterifying (saponifying) the acetic ester portion of a vinyl acetate polymer (that is, a copolymer of vinyl alcohol and vinyl acetate) or trifluorovinyl acetate. Polymer, vinyl formate polymer, vinyl pivalate polymer, t
-A polymer obtained by saponifying a butyl vinyl ether polymer, a trimethylsilyl vinyl ether polymer, or the like can be used. (For details of PVA, see PVA, "PVA".
World ", 1992, Polymer Publishing Co .; Nagano et al.
"Poval", 1981, see Polymer Publishing Co., Ltd.). The degree of "saponification" of PVA used in the present invention is
The molar percentage is preferably 70% or more, more preferably 85% or more, particularly preferably 98% or more so-called completely saponified product. The degree of polymerization is 100 or more and 5000
The following is preferable, and 200 or more and 3000 or less is more preferable. Further, the PVA used in the present invention may be modified with a small amount of a comonomer as long as the object of the present invention is not impaired.

The above modified products of PVA are also included in the scope of the present invention. These modified products mean vinyl esters, particularly vinyl acetate monomer, and other unsaturated monomer which can be copolymerized therewith in the production process of PVA. It is a copolymer of the body.
Examples of the other unsaturated monomer include olefins such as ethylene, propylene, α-hexene, and α-octene, and (meth) acrylic acid, crotonic acid, (anhydrous) maleic acid, fumaric acid, and itaconic acid. Unsaturated acids such as, and their alkyl esters and alkali salts, vinyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-
Sulfonic acid-containing monomers such as methylpropanesulfonic acid and their alkali salts, 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 and other quaternizable cationic monomers,
Examples thereof include styrene, alkyl vinyl ether, (meth) acrylamide, and others.

The ratio of these copolymerization components is not particularly limited, but is 5 relative to the vinyl alcohol unit.
It is preferably 0 mol% or less, preferably about 30 mol% or less, and various copolymerization forms such as random copolymerization, block copolymerization and graft copolymerization can be used. .

Among these copolymers, a block copolymer in which a polycarboxylic acid component is copolymerized with a polyvinyl alcohol component is particularly preferably used, and when the polycarboxylic acid component is polymethacrylic acid. Particularly preferred. Further, the block copolymer is particularly preferably an AB type block copolymer in which a polyacrylic acid chain is extended at one end of the PVA chain, and the polyvinyl alcohol block component (a) and the polyacrylic acid block copolymer are preferred. The mass ratio (a) / (b) of the acid block component (b) is 50/50 to
It is preferably 95/5, 60/40 to 90/1
When it is 0, the particularly preferable gas barrier property is completed, and the bonding property with the base material layer is remarkably completed. In addition, among the other modified products, one of the particularly preferable forms is a silyl group-modified PVA-based resin which is a saponified vinyl ester polymer modified with at least one compound having a silyl group in the molecule. .

The method for obtaining the modified polymer having such a composition is not particularly limited, but P obtained by a conventional method is used.
VA or a vinyl alcohol polymer such as modified polyvinyl acetate is reacted with a compound having a silyl group in the molecule to introduce a silyl group into the polymer, or the terminal of PVA or its modified product is activated to Introducing an unsaturated monomer having a silyl group at the polymer terminal, further graft-copolymerizing the unsaturated monomer with the vinyl alcohol polymer molecular chain, various modification methods, vinyl ester-based monomer A copolymer is obtained from a monomer and an unsaturated monomer having a silyl group in the molecule, a method of saponifying this, or a vinyl ester is polymerized in the presence of a mercaptan having a silyl group. Various methods such as introducing a silyl group at the terminal such as saponification are effectively used.

Modified PV obtained by such various methods
As the A-based resin, any resin may be used as long as it has a silyl group in the molecule as a result, but the silyl group contained in the molecule is an alkoxyl group or an acyloxyl group and a silanol group or a hydrolyzate thereof. Those having a reactive substituent such as a salt are preferable, and a silanol group is particularly preferable.

Examples of the compound having a silyl group in the molecule used to obtain these modified PVA-based resins include trimethylchlorosilane, dimethylchlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane and triethylfluorosilane. Organohalosilanes such as, trimethylacetoxysilane, dimethyldiacetoxysilane and other organosilicon esters, trimethylmethoxysilane, dimethyldimethoxysilane and other organoalkoxysilanes, trimethylsilanol, diethylsilanediol and other organosilanols, N-amiethyltrimethoxy Examples include aminoalkylsilanes such as silanes, organosilicon isocyanates such as trimethylsilicon isocyanate, and others. The degree of modification with these silylating agents can be arbitrarily adjusted depending on the type and amount of the silylating agent used and the reaction conditions.

The unsaturated monomer used in the method of saponifying a copolymer of a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule is vinyltrimethoxysilane. , Vinyltriethoxysilane, and many vinylsilane compounds such as vinylalkoxysilane and vinylmethyldimethoxysilane represented by vinyltrioxypropoxysilane, and alkyl or allyl substitution products of vinylalkoxysilane represented by vinyltriisopropoxysilane. Furthermore, 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 cited. Furthermore, a (meth) acrylamido-alkylsilane represented by 3- (meth) acrylamino-propyltrimethoxysilane and 3- (meth) acrylamido-propyltriethoxysilane can be preferably used.

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

The suitability range of the modified PVA-based resin of the present invention varies depending on the degree of modification, that is, the silyl group content, the degree of saponification, etc. It becomes a factor. The content of the silyl group is usually 30 mol% or less as a monomer containing the silyl group based on the vinyl alcohol unit in the polymer, and 1
It is preferably 0 mol% or less, and particularly preferably 5 mol% or less. The lower limit is not particularly limited,
When the amount is 0.1 mol% or more, the effect is particularly remarkable.

The silylation rate is the same as PV before silylation.
It shows the ratio of the silyl groups introduced after silylation to the amount of hydroxyl groups contained in the A-based resin.

Of course, these various PVA-based resins may be used alone, but as long as the objects of the present invention are not impaired, they can be used as a copolymer with other copolymerizable monomers or can be mixed. It can be used in combination with other resin compounds. Examples of such resins include polyacrylic acid or its esters, polyester resins, polyurethane resins, polyamide resins, epoxy resins, melamine resins, and others.

The EVOH used in the present invention preferably has a vinyl alcohol content of 40 to 80 mol% or less, more preferably 45 to 75 mol%. Further, these EVOH may be modified with a small amount of a copolymerization monomer as long as the object of the present invention is not impaired.

The EVOH is preferably modified so that it can be self-crosslinked. Further, it is preferably modified to be soluble in alcohol. A silyl group is introduced into EVOH in order to impart such properties.

The introduction of the silyl group is carried out by, for example, 3-isocyanatopropyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluoroorganohalosilane, trimethylacetoxy. Like silane, it is carried out by reacting a reactive silane compound with the hydroxyl group of EVOH.

The introduction of the silyl group, that is, the silylation needs to be carried out at least so that 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 rate is not particularly limited from the viewpoint of alcohol solubility, but it 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 silyl groups introduced after silylation to the amount of hydroxyl groups contained in the EVOH resin before silylation.

Modified EVOH having the silyl group introduced
Is dissolved in an alcohol solvent by the presence of the introduced silyl group by heating and dissolving it in alcohol or a mixed solvent of alcohol / water. In the modified EVOH dissolved in the solvent, on the other hand, a part of the introduced silyl group reacts by dealcoholization reaction and dehydration reaction to crosslink. The presence of water is essential for the above reaction, and it is preferable to use a mixed solvent of alcohol / water.

The anchor layer of the present invention has a thickness of 1 nm to 5 μm.
m is preferred. If it is less than 1 nm, the adhesion and water resistance, which are the effects of the anchor layer, deteriorate. On the other hand, if the thickness exceeds 5 μm, the effect of the anchor layer reaches the ceiling and it is uneconomical.

In the present invention, it is more preferable to provide an overcoat layer further containing a high hydrogen-bonding resin on the gas barrier layer. As the high hydrogen-bonding resin that can be used as the overcoat layer, the same resin as the high hydrogen-bonding resin that can be used in the anchor layer can be used.

The thickness of the overcoat layer is 1 nm to 5 μm.
Is preferred. If it is less than 1 nm, the effect of the overcoat layer on flexibility, bending resistance, and barrier property is small, and if it exceeds 5 μm, the effect reaches its ceiling and it is uneconomical. A more preferable thickness of the anchor layer and the overcoat layer is 10 nm to 1 μm, and a further preferable range is 50 to
It is 500 nm.

In order to further improve the gas barrier property, a tabular pigment used in the gas barrier layer can be added to the anchor layer or the overcoat layer. In particular, when the anchor layer or the overcoat layer contains a high hydrogen-bonding resin, the effect of improving the gas barrier property when the tabular pigment is used together is remarkable. For example, when a 25 μm film of biaxially oriented polypropylene is used as the substrate, the oxygen permeation rate of the film itself is 2000 to 3000 cc / m ² · 24 hr. PVA / polyethyleneimine as the anchor layer,
The gas barrier layer and the overcoat layer are sequentially laminated with PVA to form a gas barrier laminate. in this case,
Since the anchor layer and the overcoat layer are mainly composed of PVA which is a high hydrogen-bonding resin, they exhibit a high gas barrier property at low humidity. However, when the relative humidity exceeds 80%, the layer made of PVA has a poor gas barrier property and exhibits an oxygen permeability of only about 1000 cc / m ² · 24 hr. Further, the gas barrier layer has a good gas barrier property even under high humidity conditions, but minute cracks and pinholes are generated in the gas barrier layer due to bending and stretching of the gas barrier laminate. When a crack or a pinhole occurs, as described above, the gas barrier property of the base material, the anchor layer, and the overcoat layer is low under high humidity conditions, so that the gas barrier property is rapidly lowered. Conventionally, a method of obtaining a gas barrier laminate by mixing a tabular pigment with a highly hydrogen-bonding resin such as PVA (JP-A-7-251475, JP-A-7-251871)
Is known. However, in these methods, the high gas barrier property under high humidity conditions as in the present invention could not be realized unless a large amount of tabular pigment having a large particle size was added to the high hydrogen-bonding resin. Therefore, transparency (haze), which is an important quality when used as a packaging film
We could only manufacture the ones with bad quality. However, in the present invention, for example, when the tabular pigment is added to PVA to the extent that the transparency is not impaired to form the overcoat layer, 23
Oxygen permeability ° C. 90% RH is 100~200cc / ^{m 2} · 24
An overcoat layer of about hr can be obtained. In this case, even if pinholes or cracks occur in the gas barrier layer, the barrier property can be maintained as compared with the case where the overcoat layer contains no tabular pigment. More specifically,
When a crease is made with the Gelbo Flex Tester and the tabular pigment is not contained in the overcoat layer, the oxygen permeability shows a level of about 100 cc / m ² · 24 hr. The oxygen permeability becomes 1/10. Further, since the amount of the tabular pigment added is small, the transparency of the obtained gas barrier laminate is not impaired. The degree of not impairing the transparency as used herein means that the increase in haze by adding the tabular pigment to the overcoat layer is 8% or less.

2 of the gas barrier laminate of the present invention
The oxygen permeability at 3 ° C / 90% RH is 72 after the start of measurement.
After time, it is preferably 50 cc / m ² · day · atm or less, more preferably 30 cc / m ² · day · atm,
More preferably, it is 15 cc / m ² · 24 hr or less. When the oxygen permeability is 50 cc / m ² · day · atm or less, the oxygen permeability is sufficiently low that it can be put to practical use as a gas barrier laminate, and if it is 30 cc / m ² · day · atm or less. Wider range of applications that can be used. Oxygen permeability is MOC
It is a value measured by OX-TRAN / 100 type manufactured by ON company. The oxygen permeability of the gas barrier laminate of the present invention changes with time, but is almost stable after about 72 hours.

The gas barrier laminate of the present invention preferably has a haze of 8% or less, more preferably 6% or less when the support is a transparent (haze 6% or less) film. In other words, it is preferable that the haze increase value due to the provision of the gas barrier layer, the anchor layer, and the overcoat layer is closer to zero. When the haze of the laminate is higher than 8%, the film is clearly clouded, which limits its use as a packaging film. When the haze is 6% or less, the use as a packaging film is expanded. The haze is the diffuse transmittance (T
d) / calculated from total light transmittance (Tt) (reflection / transmittance meter: HR-100, MURAKAMI COLOR
RESERCH LABORATORY) value,
The smaller the haze, the better the transparency.

In order to produce the gas barrier laminate of the present invention, a gas containing at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, a tabular pigment and an acidic substance other than silicic acid. It is preferable to coat the support with a barrier coating to form a gas barrier laminate. However, depending on the type of acidic substance to be added, the alkali metal ions in the gas barrier coating and the acidic substance may cause a rapid neutralization reaction. When the neutralization reaction occurs in the paint, the viscosity of the paint increases, and when the neutralization reaction is vigorous, the paint may gel, which is not preferable. In addition, when a neutralization reaction occurs in the paint, the condensation reaction between the silicic acid condensates progresses, and the film forming property of the paint may deteriorate, resulting in deterioration of the barrier property of the coating film. It is preferable to use a paint that does not undergo a hydration reaction or has a very slow rate even if a neutralization reaction occurs. Therefore, it is preferable to add an acidic substance that does not cause a neutralization reaction in the state of being added to the coating material, but causes a neutralization reaction in the steps such as drying and heating after being applied to the base material. Such acidic substance is preferably an acidic substance composed of at least one selected from the group consisting of ammonium salts of inorganic acids, ammonium salts of organic acids, urea and boron oxide. More specific examples include ammonium salts of acidic substances such as phosphoric acid, carbonic acid, hydrochloric acid, sulfuric acid, boric acid, urea, and boron oxide. For example,
For example, when ammonium phosphate is used as the acidic substance, gas barrier paints have a rapid neutralization reaction with alkali metal ions contained in the paint because phosphoric acid is neutralized with ammonia in the paint. It doesn't happen.
However, when the gas barrier layer is formed by coating and drying, ammonia is evaporated by the heat of drying and evaporation of water to generate phosphoric acid. This phosphoric acid causes a neutralization reaction with the alkali metal ions in the gas barrier coating film to trap the alkali metal ions. Since this neutralization reaction occurs simultaneously with the coating film formation and the neutralization reaction, the alkali metal ions in the coating film can be neutralized (trapped) with an acidic substance while maintaining the coating film formation property. Therefore, water resistance and moisture gas barrier resistance are improved. Neutralizing the alkali metal ions also has the effect of promoting the dehydration condensation reaction of silicic acid (silanol groups). The water resistance is further improved as the condensation of silanol groups progresses, and the addition of an acidic substance promotes the neutralization (trap) of alkali metal ions and the dehydration condensation reaction (formation of siloxane bonds) of silanol groups. Moreover, since the alkali metal ion is neutralized by the acidic substance in the coating film, it is considered that the ability to accelerate the hydrolysis of the siloxane bond is weakened. As described above, in the present invention, the silicic acid condensate (at least one selected from alkali metal silicate or colloidal silica) and the tabular pigment include at least one composition selected from ammonium salts of acidic substances, urea, and boron oxide. It is preferable that the gas barrier coating is formed by adding the above substances to a gas barrier coating, and the coating is applied to a support to form a gas barrier layer.

Ammonium salts of acidic substances added to gas barrier coatings include ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium sulfate, ammonium hydrogen sulfate, ammonium carbonate,
Examples thereof include ammonium salts of inorganic acids such as ammonium hydrogen carbonate, ammonium nitrate and ammonium tetraborate, and ammonium salts of organic acids such as acetic acid, benzoic acid, formic acid, tartaric acid, maleic acid, malonic acid, phthalic acid and citric acid. Ammonium salt as described above, when a gas barrier coating is applied to a support and dried to form a gas barrier layer, it decomposes due to heating during heating and evaporation of water to release ammonia, and at the same time, A neutralization reaction occurs with the alkali metal ions in the gas barrier layer to form an alkali metal salt. The ammonium salt used in the present invention may be partially neutralized with an alkali metal ion such as sodium, potassium or lithium. Moreover, you may use what releases ammonia and carbon dioxide by heating like urea. In this case, an alkali metal carbonate is produced as a neutralizing salt in the gas barrier layer. Boric acid can also be used when an acidic substance containing boron is added to the gas barrier paint, but in this case the gelation rate of the paint due to the reaction with alkali metal ions in the paint is relatively fast. From the viewpoint of the stability of the paint, it is preferable to use ammonium tetraborate, potassium tetraborate or boron oxide. Ammonium tetraborate does not cause a neutralization reaction with the alkali metal ion of the alkali metal silicate even if it is added to the gas barrier paint. Ammonium tetraborate is decomposed in the process of applying a paint and heating and drying, and boric acid is generated by releasing ammonia, which causes a neutralization reaction with an alkali metal ion to form a neutralized salt.
Boron oxide exists as a dimer, trimer, or a condensate of more than a powder as a powder, and as it is, it has a weak function as an acid. However, by dissolving boron oxide in a gas barrier coating, coating the gas barrier coating and heating and drying, boron oxide is hydrolyzed by heat to form boric acid as a monomer and boric acid such as dimer and trimer. Is generated. The boric acid then undergoes a neutralization reaction with the alkali metal ions to form a neutralized salt.

The addition amount of the acidic substance other than silicic acid in the present invention is ideally the neutralization amount with respect to the alkali metal ions contained in the gas barrier coating. For example, since the phosphoric acid compound is trivalent, 1 mol of phosphoric acid is required for 3 mol of the alkali metal ion. Similarly, carbonic acid and sulfuric acid are calculated as divalent, and nitric acid is calculated as monovalent. The boric acid compound is theoretically a trivalent acid, but boric acid itself is a weak acid, boric acid itself is condensed, or silicic acid and boric acid are condensed, and the B-OH bond is B-O-B. Bonding and BOS
Because of the i-bond, not all B-OH can neutralize alkali metal ions. The inventors of the present invention have found that boric acid may be regarded as monovalent.

The amount of the acidic substance other than silicic acid added to the above-mentioned gas barrier coating does not necessarily have to be the neutralization amount, but is 10 to 500 relative to the alkali metal ion in the coating.
The molar equivalent is preferably 20 to 400 molar equivalents, more preferably 30 to 300 molar equivalents. If it is less than 10 molar equivalents, the alkali metal ions are not sufficiently neutralized,
In some cases, the effect of improving the gas barrier property under high humidity conditions may not be sufficiently obtained. On the other hand, when it exceeds 500 molar equivalents, unreacted acidic substances remain in the coating film, which hinders the film formation between the silicic acid condensates and deteriorates the gas barrier property.

The gas barrier layer obtained in the present invention is characterized by neutralizing alkali metal ions in the gas barrier layer with an acidic substance to promote the reaction of the silicic acid condensate, thereby enhancing the water resistance and the moisture resistance. Is. However, a method of applying a gas barrier coating containing an acidic substance (ammonium salt of organic acid or organic acid, boron oxide, urea) to a support and drying it, and activating the acidic substance in the drying process to neutralize the alkali Therefore, the neutralization reaction and the condensation reaction of the silicic acid in the gas barrier layer occur simultaneously. Therefore, normal drying alone may result in incomplete neutralization of alkali metal ions or insufficient condensation of silicic acid. In that case, the gas barrier property is improved by performing a humidification treatment or an aging treatment by heating in the drying step. The humidification treatment is a method in which steam is brought into direct or indirect contact with the surface of the gas barrier layer once formed. This is to hydrolyze the condensation of silicic acid formed in the gas barrier layer by humidification. If the silicic acid is condensed in a state where the silicic acid is completely packed, such humidification treatment is not necessary. However, when the coating film of the gas barrier paint is rapidly dried by increasing the drying temperature or shortening the drying time to increase productivity, silicic acids condense in the form with voids or pinholes. There is a possibility that it will end up.
In this case, the gas barrier layer cannot exhibit sufficient gas barrier properties. Then, vapor is applied to the surface of the gas barrier coating film, and the water molecules adsorbed on the surface re-open the siloxane bond formed by condensation of silicic acid. In this state, the gas barrier coating film is plasticized by water. By plasticizing, rearrangement of silicic acid condensate is promoted. If the humidification treatment is stopped in this plasticized state and the gas barrier laminate is left as it is or subjected to heat treatment, the adsorbed water is desorbed and the silicic acid condensates cause a condensation reaction. Therefore, water resistance and gas barrier properties are improved. Further, since it plays a role of promoting the neutralization reaction of the unreacted acidic substance and the alkali metal ion in the coating film of the gas barrier paint, the water resistance is further improved. As the humidifying method, any method such as a resistance heating type, an ultrasonic type, and a spraying type can be adopted. The vapor may be brought into direct contact with the gas barrier layer, or may be humidified in a high humidity atmosphere. High humidity means 70 to 100% RH, and 85 to 100% RH is more preferable. In the step of drying the gas barrier layer, the drying zone in the latter stage of the drying step may be set to high humidity or steam may be sprayed. The degree of humidification should be controlled by the condition of the gas barrier coating film. If the degree of humidification is too low, a series of reactions of cleavage, rearrangement and condensation of the silicic acid condensate will not occur easily, and the effect of improving water resistance and gas barrier property will be small. If the degree of humidification is too large, the gas barrier coating film will approach the dissolved state from the plasticized state, and the alignment will be further disturbed rather than the rearrangement of the silicic acid condensate, and the gas barrier property will decrease, which is not preferable. .

In the step of applying and drying the gas barrier coating, heating to 30 ° C. or more and holding in that state for a certain period of time and aging treatment further accelerates the condensation of silicic acid to form the formed gas. The gas barrier property of the barrier layer is further improved. Condensation of silicic acid proceeds even when dried at room temperature, but the reaction requires a long time. If this heat treatment is performed after the above-mentioned humidification treatment, it is more effective in improving the gas barrier property, and the heating aging time can be shortened. Of course, the heat aging treatment may be performed without performing the humidification treatment. The heating temperature during the aging treatment is preferably 30 to 100 ° C, more preferably 35 to 90 ° C, and most preferably 40 to 80 ° C. If the aging temperature is lower than 30 ° C, the aging time may be required for one month or longer, which makes industrial production difficult. Further, even if the aging temperature is 100 ° C. or higher, the effect of accelerating the condensation reaction reaches the ceiling, which is uneconomical. The longer the aging time, the greater the effect of improving the gas barrier property, but it is preferably 3 hours to 1 week, more preferably 12 to 72 hours, and further preferably 24 to 48 hours. If the aging time is less than 3 hours, the effect of aging is small, which is not preferable. If the aging time exceeds one week, the effect of aging will reach the ceiling and it is uneconomical. During the heat treatment, it is preferable to perform the heat treatment by a method in which the gas barrier layer does not come into direct contact with the air in order to prevent white sinter due to the reaction between the alkali metal in the gas barrier layer and carbon dioxide in the air. When the overcoat layer is formed on the gas barrier layer, the gas barrier layer may be heat-aged before the overcoat layer is formed, or the heat-aging treatment may be performed after the overcoat is formed.

In the present invention, the gas barrier layer may contain a high hydrogen-bonding resin, an aqueous emulsion of styrene-butadiene latex, acrylic ester, acrylic styrene, polyester or the like, or another water-soluble resin. The flexibility of the gas barrier layer is improved by adding such a resin to the gas barrier layer. However, since the gas barrier property tends to decrease, the addition amount is determined by the balance between the required flexibility and the gas barrier property.

Further, in the present invention, a gas barrier layer,
Additives such as a hue adjusting agent, a viscosity adjusting agent, an inorganic pigment, an organic pigment, a curing agent and a crosslinking agent can be optionally added to each of the anchor layer and the overcoat layer.

The gas barrier layered product of the present invention is obtained by coating the surface of the support with the above gas barrier coating composition and drying. Coating methods include direct gravure method, reverse gravure method, micro gravure method, roll coating method such as two roll beat coating method, bottom feed three reverse coating method, doctor knife method, die coating method, dip coating method, bar coating method. Coating method,
Kiss coating, lip coating, blade coating, air knife coating, dipping, brush coating and the like can be optionally used depending on the situation. Further, these coating methods can be used in combination. Further, the method is not limited to these methods.

As the drying method, a drying method using hot air, dry air, infrared rays, microwaves, gas burners or the like can be arbitrarily used. A drying method in which two or more of these are combined can also be used, but the method is not limited to these methods. The drying temperature is not particularly limited, but is preferably 50 to 300 ° C, more preferably 70 to 200.
C, most preferably 90-150C. If the drying temperature is lower than 50 ° C, the condensation reaction of silicic acid may not sufficiently occur. On the other hand, when the temperature exceeds 300 ° C., the reaction may proceed only in the surface layer of the gas barrier layer to form a film, which may cause a blister phenomenon. The blister phenomenon means that only the surface of the coating film is formed, and the inside of the coating film is in an undried state. It is a phenomenon. When a thermoplastic resin is used for the support, it needs to be dried at a temperature below the melting point of the resin. For example, when an OPP film is selected as the support, the drying temperature is preferably 70 to 120 ° C.
If the temperature exceeds 120 ° C, the OPP film may deteriorate in strength and change in color tone, which is not preferable.

[0116]

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

Example 1 A lithium silicate salt solution having a molar ratio of 3.5 (lithium silicate 35, solid content Li ₂ O.SiO ₂
23%, manufactured by Nippon Kagaku Kogyo Co., Ltd., diluted with ion-exchanged water to obtain a lithium silicate salt aqueous solution (solid content Li ₂ O).
・ 4% as SiO ₂ ) and synthetic smectite (Lucentite SWN, solid content 91%, average particle size 30 to 50)
nm, Co-op Chemical Co., Ltd.) was dispersed in ion-exchanged water for 30 minutes or more with a homomixer to obtain a synthetic smectite aqueous dispersion (solid content 2%), and the solid content ratio was 70/30.
And mixed with ion-exchanged water to prepare an aqueous liquid having a solid content of 3%, which is a combination of lithium silicate salt and synthetic smectite. Tetraborate ammonium tetrahydrate _{((NH 4) 2B 4 O} 7 · 4H 2 O, molecular weight 263.3
8. An aqueous solution of ammonium tetraborate (solid content: 3%) was prepared by using Wako Pure Chemical Industries, Ltd. and ion-exchanged water. Ratio of solid content of ammonium tetraborate to solid content of lithium silicate and smectite is 30/100 (solid content of ammonium tetraborate is 30 parts by mass, total solid content of lithium silicate and synthetic smectite is 100 parts by mass) As described above, the ammonium tetraborate aqueous solution was added to a 3% solid content aqueous solution of lithium silicate and synthetic smectite while stirring, and further stirred for 30 minutes to obtain a gas barrier coating.
At this time, the amount of ammonium tetraborate added was 0.82 mol in terms of boric acid with respect to 1 mol of lithium ions in the gas barrier coating. Assuming that one molecule of boric acid can neutralize one lithium ion, it means that 82 molar equivalents of ammonium tetraborate are added to the lithium ion. The obtained gas barrier coating composition was applied to the corona-treated surface of a polyethylene terephthalate film (thickness 12 μm) using a Meyer bar so that the thickness of the gas barrier layer after drying would be 0.5 μm, 2 at 100 ° C
It was dried for a minute to obtain a gas barrier laminate.

Example 2 Polyethyleneimine (Epomine P-1000, 30% aqueous solution of polyethyleneimine resin) was added to 1% of isopropyl alcohol on a corona-treated surface of a biaxially oriented polypropylene film (thickness: 25 μm).
Diluted, molecular weight 70,000, specific gravity 1.04, amine value 18 (mgeq / g.solid), amine ratio 1st / 2nd / 3rd = 25/50/25, manufactured by Nippon Shokubai Co., Ltd. % Solution is applied so that the film thickness after drying may be 0.03 μm, 80
It was dried for 2 minutes with a hot air dryer at ℃ to form an anchor layer.
Then, to a lithium silicate aqueous solution (solid content: Li ₂ O.SiO ₂ 4%) prepared in the same manner as in Example 1, the synthetic smectite aqueous dispersion (solid content: 2%) prepared in the same manner as in Example 1 was added. Each solid content ratio was mixed to be 80/20, and ion-exchanged water was further added to prepare an aqueous liquid having a solid content of 3%, which is a combination of lithium silicate salt and synthetic smectite. Boron oxide (B ₂ O ₃ , manufactured by Wako Pure Chemical Industries, Ltd.) and ion-exchanged water were used to prepare a 3% aqueous solution of boron oxide. The ratio of the solid content of boron oxide solid content and the solid content of lithium silicate and synthetic smectite is 30/100 (solid content of boron oxide is 30 parts by mass, total solid content of lithium silicate and synthetic smectite is 100 parts by mass). The above 3% aqueous solution of boron oxide was added to an aqueous solution of lithium silicate and synthetic smectite with a solid content of 3% with stirring, and further stirred for 30 minutes to obtain a gas barrier coating composition. The amount of boron oxide added at this time is 100 molar equivalent% with respect to lithium ions. The obtained gas barrier coating composition was applied onto the above anchor layer using a Meyer bar so that the thickness of the gas barrier layer after drying would be 0.3 μm, and the temperature was 100 ° C.
And dried for 2 minutes to obtain a gas barrier laminate.

Example 3 Polyethyleneimine (Epomin P-1000, an aqueous solution of 30% polyethyleneimine resin was diluted with water to 3% on a corona-treated surface of a biaxially stretched polypropylene film (thickness: 25 μm). 70,000, specific gravity 1.04, amine value 18 (mgeq /
g ・ solid), amine ratio 1st / 2nd / 3rd grade = 25/50
/ 25, an aqueous solution of Nippon Shokubai Co., Ltd. and PVA (PV
A117, a saponification degree of 99%, a completely saponified PVA, a polymerization degree of 1700, manufactured by Kuraray Co., Ltd.) was obtained by mixing a 3% aqueous solution so that the solid content mass ratio of polyethyleneimine and PVA was 10/90. Anchor coating (solid content 3%) was applied so that the film thickness after drying was 0.2 μm, and dried for 2 minutes with a hot air dryer at 80 ° C. to form an anchor layer. Then
An aqueous lithium silicate solution prepared in the same manner as in Example 1 (4% solid content Li ₂ O.SiO ₂ ) was added to a synthetic smectite aqueous dispersion prepared in the same manner as in Example 1 (solid content 2%).
Was mixed at a solid content ratio of 90/10, and ion-exchanged water was further added to prepare an aqueous liquid having a solid content of 3%, which is a combination of lithium silicate and synthetic smectite. Ammonium tetraborate aqueous solution (solid content 3%) in the same manner as in Example 1.
Was produced. The ratio of the solid content of ammonium tetraborate to the solid content of lithium silicate and synthetic smectite is 30.
/ 100 (20 parts by mass of ammonium tetraborate solid content,
The total solid content of lithium silicate and synthetic smectite is 100
(Parts by mass), the above ammonium tetraborate aqueous solution was added to a 3% aqueous solution of lithium silicate and synthetic smectite while stirring, and further stirred for 30 minutes. At this time, the addition amount of ammonium tetraborate is 70 molar equivalent% with respect to lithium ions. Epoxy silane coupling agent (KBM403, γ-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd.) in the above 3% aqueous solution
3% aqueous solution obtained by diluting) with ion-exchanged water so that the ratio of the solid content of the epoxy silane coupling agent to the solid content of lithium silicate and synthetic smectite is 30/100, and further stirred. A 3% aqueous solution was prepared to obtain a gas barrier paint. The obtained gas barrier coating composition was applied onto the anchor layer using a Meyer bar so that the dried gas barrier layer had a thickness of 0.3 μm.
It dried at 00 degreeC for 2 minutes, and formed the gas barrier layer. Using a humidifier (National steam fan type humidifier, product number FE-05KTP) on the surface of the gas barrier layer, keep the gas barrier layer surface 30 cm away from the steam generation port, and keep the vapor evenly on the surface of the gas barrier layer for 5 seconds. It was humidified. A 3% aqueous solution of PVA (PVA 117, saponification degree 99%, completely saponified PVA, degree of polymerization 1700, manufactured by Kuraray Co., Ltd.) was applied on the gas barrier layer which had been subjected to the humidification treatment,
It was coated with a Meyer bar so that the film thickness after drying was 0.3 μm, and dried using a hot air dryer at 100 ° C. for 1 minute.
The obtained OPP / anchor layer / gas barrier layer / overcoat layer laminate was placed in a polypropylene bag, sealed, and heat-aged at 40 ° C. for 24 hours to obtain a gas barrier laminate.

Example 4 The gas barrier layer of the gas barrier laminate obtained in Example 2 was humidified in the same manner as in Example 3, and PVA (PVA 117, saponification degree 99%, Fully saponified PVA, degree of polymerization 1700,
A 3% aqueous solution of Kuraray Co., Ltd. has a film thickness after drying of 0.
It was coated with a Mayer bar so as to have a thickness of 3 μm and dried at 100 ° C. for 1 minute using a hot air dryer. The obtained OPP / anchor layer / gas barrier layer / overcoat layer laminate was placed in a polypropylene bag, sealed, and heat-aged at 40 ° C. for 72 hours to obtain a gas barrier laminate.

Example 5 Instead of boron oxide, urea (H ₂ NCONH ₂ , molecular weight 60.1, melting point 132 to 1)
A gas barrier laminate was obtained in exactly the same manner as in Example 2 except that 36 ° C. and Wako Pure Chemical Industries, Ltd. were used. The amount of urea added at this time is 180 with respect to lithium ions.
It was a molar equivalent%.

Example 6 Ammonium carbonate ((NH ₄ ) 2CO ₃ , molecular weight 96.1, manufactured by Wako Pure Chemical Industries, Ltd.) was used in place of boron oxide, and the solid content of ammonium carbonate, lithium silicate and synthetic smectite were used. The ratio of combined solids is 16/100 (30 parts by mass of ammonium carbonate solids,
The total solid content of lithium silicate and synthetic smectite is 100
A gas barrier layered product was obtained in exactly the same manner as in Example 2 except that the gas barrier coating material was prepared so that the amount of the gas barrier layer coating material was adjusted to 10 parts by weight. The addition amount of ammonium carbonate at this time was 50 molar equivalent% with respect to lithium ions (ammonium carbonate was calculated as a divalent acid).

<Example 7> The ratio of the solid content of boron oxide to the solid content of lithium silicate and synthetic smectite was 1.
0/100 (solid content of boron oxide 30 parts by mass, total solid content of lithium silicate and synthetic smectite 100 parts by mass)
A gas barrier laminate was obtained in the same manner as in Example 2 except that the gas barrier coating composition was prepared so that The amount of boron oxide added at this time was 33 molar equivalent% based on lithium ions.

Example 8 The ratio of the solid content of boron oxide to the combined solid content of lithium silicate and smectite was 100.
/ 100 (solid content of boron oxide 30 parts by mass, total solid content of lithium silicate and synthetic smectite is 100 parts by mass), except that the gas barrier coating composition was prepared.
A gas barrier laminate was obtained in the same manner as in Example 2. The amount of boron oxide added at this time was 335 molar equivalent% based on the lithium ions.

Example 9 On the gas barrier layer of the gas barrier laminate obtained in Example 2, PVA (PVA117,
Saponification degree 99%, fully saponified PVA, degree of polymerization 1700,
Kuraray Co., Ltd.) and synthetic mica (NTS-5, manufactured by Topy Industries, Ltd.) were mixed at a solid content ratio of 93/7 to prepare a coating material for overcoat (solid content concentration 3%). The film thickness of the overcoat paint after drying with a Meyer bar is 0.8μ.
It is coated so that it becomes m, and it is 100 ℃ 1 using a hot air dryer.
Dry for minutes. The obtained OPP / anchor layer / gas barrier layer / overcoat layer laminate was placed in a polypropylene bag, sealed and heat aged at 40 ° C. for 72 hours to obtain a gas barrier laminate.

<Comparative Example 1> A gas barrier laminate was obtained in the same manner as in Example 1 except that ammonium tetraborate was not added.

Comparative Example 2 A gas barrier laminate was obtained in exactly the same manner as in Example 2 except that boron oxide was not added.

Comparative Example 3 Polyethyleneimine (Epomin P-1000, an aqueous solution of 30% polyethyleneimine resin was diluted to 1% with isopropyl alcohol on a corona-treated surface of a biaxially oriented polypropylene film (25 μm), and the molecular weight was 70,000. , Specific gravity 1.04, amine value 18
(Mgeq / g ・ solid), amine ratio 1st / 2nd / 3rd = 2
5/50/25; 1% solution of Nippon Shokubai Co., Ltd. was applied so that the film thickness after drying would be 0.03 μm, and dried for 2 minutes with a hot air dryer at 80 ° C. to form an anchor layer. did. PVA (PVA120, complete saponification type, degree of polymerization 2000, manufactured by Kuraray Co., Ltd.) and synthetic mica (NTS-) on the anchor layer.
No. 5, manufactured by Topy Industries, Ltd., was mixed at a solid content ratio of 93/7 to prepare a gas barrier coating material (solid content concentration 3%). The obtained gas barrier coating composition was applied with a Meyer bar so that the film thickness after drying would be 0.8 μm, and dried with a hot air dryer at 100 ° C. for 2 minutes to obtain a gas barrier layered product. It was

Comparative Example 4 PVA (PVA120, complete saponification type, degree of polymerization 2000, manufactured by Kuraray Co., Ltd.) and synthetic mica (NTS-5, Topy Industries, Ltd.) were formed on the anchor layer formed in the same manner as in Comparative Example 3. (Manufactured by KK) with a solid content ratio of 70 /
Mixing was carried out at 30 to prepare a gas barrier paint having a solid content concentration of 3%. The gas barrier coating was applied by a Meyer bar so that the film thickness after drying was 0.8 μm, and dried at 100 ° C. for 2 minutes using a hot air dryer to obtain a gas barrier laminate.

<Test Method> 1) Oxygen Permeability According to JIS-K-7126 B method (isobaric method), the coated surface was measured with an oxygen detector side at 23 ° C. and 90% RH (oxygen permeability measuring device: OX -TRAN100 type, MOCON
Made by). Regarding the oxygen permeability, the value 72 hours after the sample was set was defined as the oxygen permeability. 2) Flex resistance test Gelbo flex tester (manufactured by Tester Sangyo Co., Ltd.)
Wrinkle was performed 10 times at an angle of 440 ° C. and a linear stroke of +63.5 mm with the coated surface inside, and the oxygen permeability of the sample after the test was measured under the conditions of 23 ° C. and 90% RH (JIS- K-7126 B method (isobaric method), oxygen permeability measuring device: OX-TRAN100 type, MOCON
Made by). The oxygen permeability was a value 72 hours after the sample was set. Oxygen permeability after flex resistance test is 200cc /
m ² · 24hr or less is preferable, more preferably 100cc / m
It is less than ² / 24hr, and if 50cc / m ² · 24hr or less, the application will be expanded. 3) Haze Haze was calculated from diffuse transmittance (Td) / total light transmittance (Tt) (reflection / transmittance meter: HR-100, MURA).
KAMI COLOR RESERCH LABORA
Made by TORY). The haze (cloudiness) is preferably 8% or less, more preferably 6% or less. When the haze is higher than 8%, it is clear that the film is cloudy, and the use as a packaging film is limited, so the haze is 8%.
The following are preferred. If the haze is 6% or less, the application will be further expanded.

[0131]

[Table 1]

[0132]

According to the present invention, it has an excellent gas barrier property even after a long period of time under high humidity conditions,
It has become possible to provide a gas barrier laminate which is suitable as a packaging material and a method for producing the same, by preventing the white bloom phenomenon.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3E067 AA03 AA05 AA11 AB05 AB06                       AB23 AB26 BA12A BB15A                       BB16A BB18A BB25A BB26A                       BC03A CA06 FC01 GD01                 3E086 AD01 BA04 BA15 BA24 BA33                       BB02 BB03 BB05 BB15 CA04                       CA11 CA23 DA08                 4F100 AA02B AA02C AA03B AA03C                       AA04B AA04C AA07B AA07C                       AA08B AA08C AA31B AA31C                       AC03B AC03C AC10B AC10C                       AH02D AH02E AH03D AH03E                       AH08B AH08C AK01D AK07                       AK21D AK21E AK31D AK31E                       AK42 AR00B AR00C AR00D                       AR00E AT00A BA02 BA03                       BA04 BA05 BA06 BA07 BA10B                       BA10C BA10D BA10E BA13                       CA13B CA13C DE02B DE02C                       EH46 EH462 EJ25E EJ38                       EJ55 EJ65D GB15 GB23                       JA02B JA02C JB07D JB07E                       JD03 JD04 JK04 JN01 YY00B                       YY00C

Claims (11)

[Claims] 1. A gas barrier laminate having a gas barrier layer provided on at least one surface of a support, wherein the gas barrier layer is at least one silicic acid condensate selected from alkali metal silicate salts or colloidal silica, a tabular pigment,
A gas barrier laminate comprising a neutral salt formed of an alkali metal salt and an acidic substance other than silicic acid. 2. A silicic acid condensate has the general formula M ₂ O.nSiO ₂
2. At least one selected from sodium silicate, potassium silicate, and lithium silicate represented by (n> 0, M = Na, K, Li).
The gas barrier laminate described. 3. The gas according to claim 1, wherein the neutralized salt is at least one selected from phosphoric acid compounds, sulfuric acid compounds, carbonic acid compounds, nitric acid compounds and boron compounds. Barrier laminate. 4. The gas barrier laminate according to claim 1, wherein the gas barrier layer contains a hydrolyzed condensate of a metal alkoxide having an organic functional group. 5. The gas barrier laminate according to claim 1, wherein the tabular pigment is at least one selected from smectite clay and mica group. 6. The gas barrier laminate according to claim 1, wherein an anchor layer containing a nitrogen-containing compound is present between the support and the gas barrier layer. 7. The gas barrier laminate according to claim 6, wherein the nitrogen-containing compound is at least one selected from polyalkyleneimine and polyalkyleneamine. 8. The gas barrier laminate according to claim 6, wherein the anchor layer contains at least one selected from high hydrogen-bonding resins and water resistance improvers. 9. An overcoat layer containing a high hydrogen-bonding resin is provided on the gas barrier layer.
9. The gas barrier laminate according to any one of to 8. 10. At least one silicic acid condensate selected from alkali metal silicates or colloidal silica, a tabular pigment, an ammonium salt of an inorganic acid, an ammonium salt of an organic acid, urea, and boron oxide. A method for producing a gas barrier laminate, which comprises applying a gas barrier coating material containing at least one or more acidic substances to a support to form a gas barrier layer. 11. The method for producing a gas barrier laminate according to claim 10, wherein the gas barrier coating material contains an acidic substance in an amount of 10 to 500 equivalent mol% with respect to the alkali metal ion.