JP2003170522A - Gas barrier laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier laminate having excellent gas barrier properties even if held in the atmosphere under a high humidity condition over a long period of time and suitable as a packaging material because a whitening phenomenon is prevented. <P>SOLUTION: In the gas barrier laminate wherein a gas barrier layer is formed on at least the single surface of a support, the gas barrier layer is formed by successively laminating two layers, that is, a first gas barrier layer (1) containing at least one silicic acid condensate selected from an alkali metal silicate and colloidal silica and a second gas barrier layer (2) containing a highly hydrogen-bondable resin and an acidic substance from a support side. <P>COPYRIGHT: (C)2003,JPO

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 provides a gas barrier laminate which is suitable as a packaging material and has excellent gas barrier properties even when left in the atmosphere for a long time under a high humidity condition. Is.

[0014]

The present invention adopts the following means in order to solve the above problems. That is, the first aspect of the present invention is a gas barrier laminate in which a gas barrier layer is formed on at least one surface of a support, and the gas barrier layer is formed by sequentially laminating the following two layers from the support side. It is a laminated body. (1) A first gas barrier layer containing at least one silicic acid condensate selected from alkali metal silicates or colloidal silica. (2) A second gas barrier layer containing a high hydrogen-bonding resin and an acidic substance.

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

A third aspect of the present invention is that the acidic substance is at least one selected from phosphoric acid compounds, sulfuric acid compounds, carbonic acid compounds, and boron compounds.
The gas barrier laminate according to any one of 1.

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 tabular pigment.

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

A sixth aspect of the present invention is that the first gas barrier layer comprises
The gas barrier laminate according to any one of the first to fifth aspects of the present invention, which contains an acidic substance other than silicic acid.

The seventh aspect of the present invention is that an acidic substance other than silicic acid is
Phosphoric acid compounds, sulfuric acid compounds, carbonic acid compounds, nitric acid compounds,
The gas barrier laminate according to the sixth aspect of the present invention, which is at least one kind selected from boron compounds.

The eighth aspect of the present invention is the gas barrier laminate according to any one of the first to seventh 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 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 anchor layer is present between the support and the gas barrier layer.

The tenth aspect of the present invention is the gas barrier laminate according to the ninth aspect of the present invention, wherein the anchor layer contains at least one selected from the group consisting of nitrogen-containing compounds and highly hydrogen-bonding resins.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The first gas barrier layer in the present invention contains at least one kind of silicic acid condensate selected from alkali metal silicates and colloidal silica.

Among 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.

Although a high molar ratio alkali metal silicate having a molar ratio of more than 10 is not generally commercially available, a method of adding various alkali metal hydroxides to amorphous silica or colloidal silica and dissolving them, It can be prepared by a method of dissolving amorphous silica or colloidal silica in a commercially available alkali metal silicate, and the alkali metal silicate thus prepared can also be used in the present invention. When using a high molar ratio alkali metal silicate, use a very thin tabular pigment with a specific shape or 0.5 μm
When the following ultra-thin film is formed so that the shrinkage in the thickness direction of the thin film is about 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 by 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.

[0030] 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 second gas barrier layer in the present invention contains a high hydrogen-bonding resin and an acidic substance. The high hydrogen-bonding resin that can be used for the second gas barrier layer is not particularly limited as long as it is a resin having film-forming properties. As an example of the high hydrogen-bonding resin, polyvinyl alcohol, ethylene vinyl alcohol copolymer, polycarboxylic acid, polyketone, polyacrylamide, polyamine, polyacrylonitrile, polyethylene glycol, polyhydric alcohol such as erythryl, starch, cellulose and so on.
In order to exhibit high hydrogen bondability, the resin may have a group having active hydrogen or a polar group capable of forming a hydrogen bond. As an example of a group having active hydrogen, a hydroxyl group (—O
H), amino group _(-NH 2), imino group (-NH-),
Carboxyl group (-COOH), amide group (-CONH
_2), sulfuric acid group _(-SO 3 H), phosphoric acid group _(-PO 4 H)
And so on. Further, as a polar group capable of forming a hydrogen bond, a carbonyl group (-C = O), a nitrile group (-C
N), ether group (-O-), thioether group (-S)
-) And the like.

Among the above-mentioned highly hydrogen-bonding resins having a polar group, a resin having a hydroxyl group is preferable from the viewpoint of gas barrier properties. For example, polyvinyl alcohol (PVA) and ethylene vinyl alcohol copolymer (EVOH) are preferable. When a high hydrogen-bonding resin such as PVA or EVOH is used as the second gas barrier layer, the second gas barrier layer may fill cracks, pinholes, etc. generated in the first gas barrier layer centered on the silicic acid condensate. Not only
It is possible to provide a gas barrier laminate that plays a role of protecting the first gas barrier layer and is excellent in flexibility and flexibility.

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 the PVA used in the present invention is preferably 70% or more in terms of molar percentage, and more preferably 8%.
5% or more is preferable, and 98% or more of so-called completely saponified product is particularly preferable. The degree of polymerization is 100 to 50.
00 is preferable, and 200 to 3000 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 modified products of the above PVA are also within the scope of the present invention. These modified products are vinyl esters, particularly vinyl acetate monomer, and other unsaturated monomer which can be copolymerized with them in the process of producing 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 include styrene, alkyl vinyl ethers, (meth) acrylamides, and the like.

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, among these copolymers, for the polyvinyl alcohol component,
A block copolymer in which a polycarboxylic acid component is copolymerized is particularly preferably used, and is particularly preferable when the polycarboxylic acid component is polymethacrylic acid. 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. It is preferable that the mass ratio (a) / (b) of the acid block component (b) is 50/50 to 95/5, and in the case of 60/40 to 90/10, particularly preferable gas barrier properties are completed. The bond properties with the substrate layer are outstandingly complete. Among the other modified products, one of the particularly preferred forms is a silyl group-modified PVA made of a saponified vinyl ester polymer modified with at least one compound having a silyl group in the molecule.
There are system resins.

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 for obtaining 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, and alkyl or allyl substitution products of vinylalkoxysilane, such as vinyltriisopropoxysilane. Further, a polyalkylene glycol vinyl silane in which a part or all of these alkoxy groups is substituted with a polyalkylene glycol such as polyethylene glycol, etc. may be mentioned. 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.

92 The suitability range of the modified PVA-based resin of the present invention varies depending on the modification degree, that is, the silyl group content, the saponification degree, etc. It becomes a factor. The content of silyl group is usually
The amount of the silyl group-containing monomer based on the vinyl alcohol unit in the polymer is 30 mol% or less, preferably 10 mol% or less, and particularly preferably 5 mol% or less. The lower limit is not particularly limited, but the effect is remarkably exhibited when it is 0.1 mol% or more.

The silylation rate is the same as the 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 made into 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. Above EV
The modification of OH is preferably modified so as to be self-crosslinkable. 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, for example, 3-isocyanatopropyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluoroorganohalosilane,
It is carried out by reacting a reactive silane compound with a hydroxyl group of EVOH, such as trimethylacetoxysilane.

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

Like the first gas barrier layer in the present invention, a gas barrier layer mainly composed of a silicic acid condensate has a gas barrier property which deteriorates with time under high humidity conditions. The cause was assumed as follows. That is, under high humidity, the alkali metal ions contained in the gas barrier layer gradually adsorb and absorb water, so that the aqueous solution of alkali metal ions moves in the first gas barrier layer and gradually becomes a silicic acid condensate or The siloxane bond (Si-O-Si bond) of colloidal silica 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 excess water is absorbed by the first 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 the coating and drying process 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 above gas barrier laminate 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. If 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, and moisture, oxygen, or the like may pass through.

The mechanism of the white bloom 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 the crystal grows to ¼ or more (100 nm or more) of the wavelength of visible light, and the number thereof increases, the film becomes white due to diffuse reflection of visible light. 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.

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 mainly composed of the silicic acid condensate has drawbacks such as the occurrence of a white flower phenomenon due to the adsorption of water and the deterioration of the gas barrier property.

Therefore, the inventors of the present invention have added an alkali metal ion contained in the first gas barrier layer containing at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, with a high hydrogen bondability. By forming a second gas barrier layer containing a resin and an acidic substance, the acidic substance contained therein neutralizes the alkali metal ions, and prevents the white sinter and the deterioration of the gas barrier property under high humidity conditions. Was successful. That is, the alkali metal ions contained in the first gas barrier layer are neutralized with the acidic substance of the second gas barrier layer to prevent adsorption of water by the alkali metal and the cleavage of the siloxane bond to prevent the gas barrier layer. It prevents the deterioration of sex.

In the present invention, the acidic substance used in the second gas barrier layer is not particularly limited as long as it can neutralize alkali metal ions. Specifically, inorganic acid compounds such as phosphoric acid, carbonic acid, hydrochloric acid, nitric acid and sulfuric acid, organic acids such as acetic acid, benzoic acid, formic acid, tartaric acid, maleic acid, malonic acid, phthalic acid and citric acid, boron oxide, tetraborane. Examples thereof include ammonium compounds, boron compounds such as sodium tetraborate, boric acid and boric anhydride, silicic acid, and metal oxides such as titanium and zirconium. In the case of a divalent or higher acid, an acidic substance partially neutralized with an alkali metal or an alkaline earth metal may be used. For example, lithium hydrogen sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, lithium hydrogen carbonate, lithium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, dilithium hydrogen phosphate, disodium hydrogen phosphate, phosphoric acid Examples include dipotassium hydrogen.

In the present invention, the acidic substance contained in the second gas barrier layer is preferably at least one selected from phosphoric acid compounds, carbonic acid compounds and boron compounds. Particularly, it is particularly preferable when the silicic acid condensate contained in the first gas barrier layer is lithium silicate. When the acidic substance contained in the second gas barrier layer neutralizes the alkali metal ions contained in the first gas barrier layer, an alkali metal salt is produced. However, since some alkali metal salts exhibit water solubility and hygroscopicity, the alkali metal salt neutralized by the second gas barrier layer acts to attract water, resulting in improved moisture gas barrier resistance. May not be performed. However, among the alkali metal salts,
Lithium carbonate (Li ₂ CO ₃ ) and lithium phosphate (Li
₃ PO ₄ ) has extremely low solubility in water and low hygroscopicity. When the silicic acid condensate contained in the first gas barrier layer is lithium silicate and the lithium ions are neutralized with the carbonate ions or phosphate ions contained in the second gas barrier layer, the gas barrier property is extremely strong A film is formed. In the present invention, in order to efficiently generate lithium carbonate or lithium phosphate by neutralization, as the acidic substance in the second gas barrier layer, lithium hydrogen carbonate partially neutralized with lithium ions in advance is used. It is particularly preferable to use dilithium hydrogen phosphate.
The existence of dilithium hydrogen phosphate as a simple substance is not known, but it can be produced by adding a necessary amount of lithium hydroxide to an aqueous solution of phosphoric acid or lithium dihydrogen phosphate.

Further, in the present invention, the ammonium salt of an acidic substance obtained by neutralizing the above acidic substance with ammonia and urea are also included in the acidic substance. Since ammonium salts of acidic substances release ammonia by heating and evaporation of water, neutralization does not occur immediately after coating the second gas barrier layer on the first gas barrier layer, but the second gas barrier layer Since ammonia is generated in the process of drying the layer, alkali metal ions in the first gas barrier layer can be neutralized. Further, since urea decomposes into ammonia and carbon dioxide when heated, it can be similarly used as an acidic substance. Examples of acidic substances neutralized with ammonia include ammonium aluminum sulfate, ammonium sulfate, ammonium hydrogen carbonate, ammonium carbonate, ammonium acetate, ammonium tartrate,
Examples thereof include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and ammonium phosphate.

Further, as the acidic substance, a boron compound or a silicic acid compound is also preferable. Boric acid and silicic acid are weak acids themselves and can neutralize alkali metal ions, but boric acid and silicic acid themselves undergo condensation dehydration reaction. Therefore,
It not only neutralizes the alkali metal ions, but also has the function of confining the alkali metal ions in the boric acid or silicic acid network. Therefore, the use of boric acid or silicic acid as an acidic substance has the effect of improving the water resistance of the gas barrier layer. Silicic acid cannot be used as an aqueous solution because it is unstable in water, but it is preferably used as an alcohol solution of alkoxide silane (tetraethoxysilane, tetramethoxysilane, etc.) (which may contain water, acid, alkali, etc.). .. For example, tetraethoxysilane decomposes with heating and evaporation of the solvent in the drying process to generate silicic acid. By utilizing this property, it can be used as an acidic substance.

Among the above acidic substances, phosphoric acid or phosphoric acid compounds such as partially neutralized products of phosphoric acid with lithium ions or ammonia, sulfuric acid or sulfuric acid compounds such as partially neutralized products of sulfuric acid with lithium ions or ammonia, carbonic acid or Carbonic acid compounds such as partially neutralized products of carbonic acid with lithium ions and ammonia, and boron compounds such as boric acid, boric oxide, and ammonium tetraborate are particularly preferable because of excellent moisture resistance.

The amount of acidic substance in the second gas barrier layer used in the present invention is determined by the amount of alkali metal ions contained in the first gas barrier layer. That is, with respect to the amount of alkali metal ions in the first gas barrier layer, it is preferable that the second gas barrier layer contains 10 to 500 mol% of an acidic substance, and more preferably 20 to 400 mol%. Most preferably, it is 50 to 200 equivalent%. When the amount of the acidic substance is less than 10 mol%, the effect of neutralizing alkali metal ions to improve the moisture barrier property and the effect of preventing white fluff are small.
If the amount exceeds 00 equivalent mol%, not only the effect reaches the ceiling but also it is not economical.

In the present invention, it is more preferable that the gas barrier layer (first gas barrier layer and / or second gas barrier layer) contains a tabular pigment. It is further preferred that the first gas barrier layer contains a tabular pigment. When the first gas barrier layer contains a tabular pigment, the silicic acid condensate and the tabular pigment can be used in combination to improve the resistance to volume shrinkage (crack prevention). 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 brings not only the effect of preventing the generation of cracks due to the shrinkage accompanying the condensation of the silicic acid condensate, but also the unique effect of the gas barrier property. The tabular pigment is a pigment having a generally tabularity, and in the present invention, it particularly refers to a pigment having a ratio of major axis to thickness (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. Incidentally, such an effect becomes more remarkable when the tabular pigment is contained in the second gas barrier layer.

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. Smectite clay is composed of three-layered crystals, and montmorillonite, beidellite, nontrolite, saponite, iron saponite, hectorite, sauconite, stipunsite, hectite, etc. 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 pale yellow or white fine powder, and their size is 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 from 10 nm to 10 μm.
Those between m are preferable, and more preferably 10n.
It is about 5 to 5 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 10 μm, it may cause an appearance defect such as an increase in haze,
It is not preferable because the film forming property of the silicic acid condensate is lowered.

The tabular pigment usable in the present invention is
From the viewpoint of transparency of the gas barrier laminate, the particle size is 1 μm.
The following is preferable. Furthermore, when the gas barrier laminate is a film and is used for applications where transparency is particularly important (for example, food applications), this particle size is 0.5 μm.
It is more preferably m or less. The transparency is preferably 80% or more (more preferably 85% or more) and the haze is in the range of 0.5 to 10% in terms of the total light transmittance at a wavelength of 500 nm. Such transparency can be obtained, for example, by using a commercially available spectrophotometer (Shimadzu Autograph UV-3
100PC type: manufactured by Shimadzu Corporation) can be preferably used for measurement.

The tabular pigment in the present invention may optionally have an aspect ratio of 5 or more obtained by dividing the average particle diameter by the thickness, but an aspect ratio of 20 or more is more preferable 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.

When a tabular pigment is added to the first gas barrier layer, the ratio of the silicic acid condensate to the tabular pigment can be arbitrarily determined depending on the situation. 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, preferably 99/2 to 20/80, more preferably 99/3 to.
It is 30/70. If the ratio of the tabular pigment is less than 1% by mass, the effect of preventing cracks becomes small. If the proportion of the tabular pigment exceeds 90% by mass, the gas barrier property may deteriorate.

When a tabular pigment is added to the second gas barrier layer, the ratio of the high hydrogen-bonding resin to the tabular pigment can be arbitrarily determined depending on the situation. If a tabular pigment having an aspect ratio of several hundreds or more is used, the gas barrier property is improved even if the amount of the tabular pigment used is several percent or less. But,
When the amount of the tabular pigment used is large, the effect of filling the defects of the first gas barrier layer by the resin and improving the flexibility becomes small. Therefore, the ratio of the high hydrogen-bonding resin to the tabular pigment is 99.9 / 0.1 to 30 in terms of mass blending ratio.
/ 70 is preferable, and more preferably 99.5 / 0.5 to
35/65, more preferably 99/1 to 40/60. Further, the tabular pigment used in the second gas barrier layer is surface treated with a silane coupling agent, a titanate coupling agent, or the like, or a surface treatment with a quaternary ammonium salt compound is a resin. This is preferable because the adhesion of the tabular pigment is improved. Further, a crosslinking agent that reacts with the resin may be added to improve water resistance.

In order to further improve the moisture gas barrier resistance, various acidic substances defined above can be added to the first gas barrier layer in addition to silicic acid. Specifically, inorganic acid compounds such as phosphoric acid, carbonic acid, hydrochloric acid, nitric acid, sulfuric acid,
Organic acid compounds such as acetic acid, benzoic acid, formic acid, tartaric acid, maleic acid, malonic acid, phthalic acid and citric acid, boron oxide, ammonium tetraborate, sodium tetraborate, boric acid, boron compounds such as boric anhydride, Examples thereof include oxides of metals such as titanium and zirconium. These acidic substances are present in the first 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 neutralized salts, alkali metal phosphates, alkali metal carbonates, alkali metal sulfates, alkali metal nitrates, and borate alkali metal salts are preferable in consideration of stability of the gas barrier layer and water resistance. 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 produce the gas barrier laminate of the present invention, at least one silicic acid condensate selected from alkali metal silicates or colloidal silica, a tabular pigment, and a gas barrier coating containing an acidic substance other than silicic acid. Is preferably applied to a support to form a gas barrier laminate.

However, depending on the kind of the 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 specifically, phosphoric acid, carbonic acid, hydrochloric acid,
Examples thereof include ammonium salts of acidic substances such as sulfuric acid and boric acid, urea, and boron oxide.

For example, when ammonium phosphate is used as the acidic substance, the gas barrier coating composition has a phosphoric acid neutralized with ammonia in the coating composition. Does not cause neutralization reaction rapidly. 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. This neutralization reaction occurs because the coating film formation and the neutralization reaction occur simultaneously.
The alkali metal ions in the coating film can be neutralized (trapped) with an acidic substance while maintaining the film forming property of the coating material.
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 to add the above substances as a coating material for forming the first gas barrier layer (first gas barrier coating material) and apply the coating material to a support to form the first gas barrier layer.

The ammonium salt of the acidic substance added to the first gas barrier coating is ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium sulfate, ammonium hydrogen sulfate, ammonium carbonate, ammonium hydrogen carbonate, ammonium nitrate. , Ammonium salts of inorganic acids such as ammonium tetraborate, acetic acid, benzoic acid, formic acid, tartaric acid, maleic acid, malonic acid,
Examples thereof include ammonium salts of organic acids such as phthalic acid and citric acid. The ammonium salt as described above decomposes and releases ammonia by heating and drying during the formation of the gas barrier layer when the first gas barrier coating material is applied to the support and dried to form the gas barrier layer. At the same time, it causes a neutralization reaction with 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.

Further, a substance which releases ammonia and carbon dioxide by heating, such as urea, may be used. In this case, an alkali metal carbonate is formed as a neutralizing salt in the first gas barrier layer. Boric acid can also be used when an acidic substance containing boron is added to the first gas barrier coating, but in this case, the gelation rate of the coating due to reaction with alkali metal ions in the coating is compared. Since it is relatively fast, it is preferable to use ammonium tetraborate, potassium tetraborate, boron oxide or the like from the viewpoint of stability of the coating material. Ammonium tetraborate does not cause a neutralization reaction with the alkali metal ion of the alkali metal silicate even if added to the first gas barrier coating. Applying paint, ammonium tetraborate decomposes in the process of heating and drying,
Boric acid is generated by releasing ammonia, which causes a neutralization reaction with alkali metal ions 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 or boric acid such as a dimer or trimer. Is generated. The boric acid then undergoes a neutralization reaction with the alkali metal ions to form a neutralized salt.

Ideally, the amount of the acidic substance other than silicic acid added to the first gas barrier coating composition of the present invention is neutralized with respect to the alkali metal ions contained in the coating composition. 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,
Since silicic acid and boric acid are condensed and the B—OH bond becomes a B—O—B bond or a B—O—Si 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 first gas barrier coating does not necessarily have to be the neutralization amount, and 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.

In order to improve the flexibility of the gas barrier layered product and the adhesion between the gas barrier layer and the support or between the gas barrier layers, the hydrolytic condensation product of the metal alkoxide having an organic functional group is used as the gas barrier layer ( It may be contained in the first gas barrier layer and / or the second gas barrier layer). 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 metal alkoxide is contained in the first gas barrier layer.
If included, a metal group containing a hydrolyzed organic functional group.
Lucoxide condenses with silicic acid condensates and flat pigments in paints.
A reaction occurs, or metal alkoxides condense with each other.
Cause a reaction. This hydrolysis-condensation reaction occurs even in paint.
However, when the paint is applied to the support and then dried by heating, it becomes more condensed.
Is more likely to occur. Metal alkoxy having organic functional group
Is used as a flat pigment or silicic acid condensate in the gas barrier coating.
Surrounded by gas, the organic functional groups were isolated inside the gas barrier layer.
Exists in shape. Therefore, silicic acid condensation occurs around organic functional groups.
A shape with voids at the molecular level without further condensation of the product
Take Therefore, it gives flexibility to the coating film. The voids are molecular
Since it is a bell, the adverse effect on the gas barrier is extremely small.
Sai. In addition, the organic functional group is a reactive functional group such as epoxy.
If it is a group, it reacts with silanol and epoxy and is flexible
It has the effect of improving not only the water resistance but also the water resistance. On the other hand, the
When the two gas barrier layer contains a metal alkoxide,
The metal alkoxide having a hydrolyzed organic functional group is
Compatible with high hydrogen bonding resins. In addition, crosslinkable organic functional
If there is a group, it will undergo a crosslinking reaction with the high hydrogen bonding resin.
You The hydrolyzed metal alkoxide is silanol.
Since it has a group, silicic acid condensation contained in the first gas barrier layer
It causes a condensation reaction with the silanol group of the compound. Therefore,
Improved adhesion between the first gas barrier layer and the second gas barrier layer
To do.

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 has a polyvalent metal atom (T
i, Al, etc.), for example, isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tricumyl phenyl titanate, and isopropyl tri (N-amidoethyl aminoethyl). It includes titanate compounds such as titanates, as well as aluminum compounds such as acetoalkoxyaluminium 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, and further preferably 5 to 50 parts by mass, when the alkali silicate condensate or the resin is 100 parts by mass. Is. The amount of metal alkoxide having an organic functional group is 1
If the amount is less than 100 parts by mass, the effect of improving the flexibility or the adhesion by the metal alkoxide having an organic functional group may be insufficient, and if it exceeds 100 parts by mass, the gas barrier property may be deteriorated. There is a nature.

The thickness of the first and second gas barrier layers is not particularly limited, but is preferably 1 nm to 5 μm. When the gas barrier layer has a thickness of less than 1 nm, the gas barrier property becomes poor. On the other hand, when the thickness is more than 5 μm, the effect of the gas barrier property reaches the ceiling and it is uneconomical. The more preferable range of the gas barrier layer is 10 nm to 1 μm, and 50 nm to 5 μm.
00 nm is a more preferable range.

The support which 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 first 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. Absent. As a method of activating the synthetic resin surface, corona discharge treatment, plasma discharge treatment, black mixed acid solution treatment, fuming sulfuric acid treatment, sulfuric acid solution treatment,
Hydrophilic hydroxyl groups, carbonyl groups, ester groups, carboxylic acid groups, ether bonds, amino groups, imino groups, amide groups, sulfate groups, amide groups, etc. on the surface of synthetic resin films, etc. A sex component 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 by such surface treatment alone (when the base material is a polyolefin resin, etc.), 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, these are preferred as the polyalkyleneimine used in the present invention are polyethyleneimine and polypropyleneimine, and particularly preferred is 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 a compound having an epoxy group such as a monoepoxy compound or a diepoxy compound with an amine compound, an adduct of a compound having a hydroxyl group such as ethylene oxide or propylene oxide with an amine compound, 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 above-mentioned modification, 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 which reacts with the silicic acid condensate as described above, which is 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 before use. You can also You may use the said nitrogen-containing compound in mixture of 2 or more types.

In the present invention, by adding a high hydrogen-bonding resin to the anchor layer containing the nitrogen-containing compound as described above, the anchor layer can be provided with a gas barrier property and the gas barrier property can be improved. The high water-bonding resin that can be used is preferably the same as the high hydrogen-bonding resin that is preferably used for the second gas barrier layer described above. Further, when a high hydrogen-bonding resin is used for the anchor layer, the high hydrogen-bonding resin and the first gas barrier layer are mixed with each other to form an organic / inorganic (high hydrogen-bonding resin and silicic acid condensate) composite (organic). It is ideal to have a tilted structure composed of an inorganic compound) and the flexibility of the gas barrier laminate can be improved.

Further, a water resistance improver may be added to the anchor layer for the purpose of improving water resistance. The water resistance improver is primarily an epoxy compound. The epoxy compound is an epoxy compound containing several epoxy groups such as mono, 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.

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 mixed liquid thereof depending on the type of the nitrogen-containing compound. Coating solution concentration is 0.01-2
It is 0%, preferably about 0.1 to 5%.

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 thickness of the anchor layer of the present invention is preferably 1 nm to 5 μm. If it is less than 1 nm, the adhesion and water resistance, which are the effects of the anchor layer, deteriorate. Also, 5
If the thickness is more than μm, the effect of the anchor layer reaches the ceiling and it is uneconomical.

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.

In the gas barrier laminate of the present invention, when the support is a transparent (haze 6% or less) film, the haze is preferably 8% or less, more preferably 6% or less. 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.

Coating the first and second gas barrier coatings,
In the step of drying, heating at 30 ° C. or higher, maintaining the state for a certain period of time, and aging treatment further accelerates the condensation of silicic acid and further improves the gas barrier property of the formed gas barrier layer. 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 can shorten the heating aging time. 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. Further, 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 4 hours.
8 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, the heat treatment may be carried out by a method in which the gas barrier layer does not come into direct contact with 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. preferable. The second gas barrier layer may be formed after heat aging the first gas barrier layer, or the heat aging treatment may be performed after forming the second gas barrier layer.

In the present invention, the first 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 other water-soluble resin. By adding such a resin to the gas barrier layer, the flexibility of the gas barrier layer can be improved. However, since the gas barrier property tends to be lowered by adding the above resin, the addition amount is determined by the balance between the required flexibility and the gas barrier property.

In the present invention, each of the first and second gas barrier layers and the anchor layer has a tint adjusting agent,
Additives such as a viscosity modifier, an inorganic pigment, an organic pigment, a curing agent and a crosslinking agent can be optionally added.

The gas barrier laminate of the present invention has the above-mentioned first and second gas barrier paints applied on the surface of a support,
It is obtained by drying. The coating method includes a direct gravure method, a reverse gravure method, a micro gravure method, a roll coating method such as a two roll beat coating method and a bottom feed three reverse coating method, a doctor knife method, a die coating method, a dip coating method, and a bar coating method. A 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.

[0122]

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 a sodium silicate salt solution with a molar ratio of 3.2 (sodium silicate No. 3, solid content Na ₂ O · S)
38% as iO ₂ (manufactured by Tokuyama Corp.) was diluted with ion-exchanged water to obtain a sodium silicate aqueous solution (solid content Na).
4% as ₂ O / SiO ₂ ) 1 in terms of solid content
00/50 (lithium silicate / sodium silicate) were mixed to prepare an aqueous liquid having a solid content of 4% to be the first gas barrier coating material. The obtained first gas barrier coating was applied to a corona-treated surface of a polyethylene terephthalate film (thickness: 12 μm) using a Meyer bar to obtain a gas barrier layer having a thickness of 0.2 μm (the coating amount was about 10 μm). 0.4 g / m ² ) so that 1
After drying at 00 ° C for 2 minutes to form a first gas barrier layer, polyvinyl alcohol (PVA 117, saponification degree 99%, fully saponified PVA,
A 3% aqueous solution having a polymerization degree of 1700 and manufactured by Kuraray Co., Ltd. was prepared. Separately, phosphoric acid (special grade, Wako Pure Chemical Industries, Ltd.) was diluted with ion-exchanged water to a phosphoric acid concentration of 3%, and a 3% lithium hydroxide aqueous solution (lithium hydroxide reagent diluted with ion-exchanged water) Were mixed so that the molar ratio of phosphoric acid and lithium hydroxide was 1: 2 to prepare a 3% aqueous solution of dilithium hydrogen phosphate. A 3% aqueous solution of PVA 117 and a 3% aqueous solution of dilithium hydrogen phosphate were mixed so that each solid content was 100/20 (PVA / dilithium hydrogen phosphate) to prepare a second gas barrier coating composition. .
The thickness of the gas barrier layer after drying the second gas barrier coating composition on the first gas barrier layer using a Meyer bar is 0.
It was applied so as to have a thickness of 2 μm (applied amount of about 0.3 g / m ² ) and dried at 100 ° C. for 2 minutes to form a second gas barrier layer to obtain a gas barrier laminate.

Example 2 Polyethyleneimine (Epomin P-1000, an aqueous solution of 30% polyethyleneimine resin diluted to 3% with water) was added to the corona-treated surface of a biaxially stretched polypropylene film (thickness: 25 μm) to obtain a molecular weight. 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 (PVA
117, saponification degree 99%, completely saponified PVA, polymerization degree 1
Membrane after drying a paint for anchor (solid content 3%) obtained by mixing 3% aqueous solution of 700, manufactured by Kuraray Co., Ltd. so that the solid content mass ratio of polyethyleneimine and PVA is 10/90. The coating was applied so that the thickness was 0.2 μm, and the coating was dried with a hot air dryer at 80 ° C. for 2 minutes to form an anchor layer. Example 1
Lithium silicate salt aqueous solution (solid content Li ₂
O.SiO ₂ (4%), synthetic smectite (Lucentite SWN, solid content 91%, average particle size 30 to 5)
Synthetic smectite aqueous dispersion (solid content 2%) obtained by dispersing 0 nm, manufactured by Coop Chemical Co., Ltd. in ion-exchanged water with a homomixer for 30 minutes or more has a solid content ratio of 75 /.
Mix so as to be 25, and then add ion-exchanged water to obtain a solid content of 3 including lithium silicate salt and synthetic smectite.
% Aqueous solution was prepared. 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 solid content of boron oxide solid content and solid content of lithium silicate and synthetic smectite is 15
/ 100 (the solid content of boron oxide is 15 parts by mass, the total solid content of lithium silicate and synthetic smectite is 100 parts by mass), the above-mentioned aqueous solution of 3% boron oxide is added to an aqueous system containing 3% of solid content of lithium silicate and synthetic smectite. It was added to the liquid with stirring, and further stirred for 30 minutes to obtain a first gas barrier coating material. The obtained first gas barrier coating composition was applied onto the above-mentioned anchor layer using a Meyer bar so that the thickness of the gas barrier layer after drying would be 0.2 μm.
It dried at 2 degreeC for 2 minutes, and obtained the 1st gas barrier layer. Then, using polyvinyl alcohol (PV
A 3% aqueous solution of A117, saponification degree 99%, completely saponified PVA, polymerization degree 1700, manufactured by Kuraray Co., Ltd. was prepared.
Separately, phosphoric acid (special grade, Wako Pure Chemical Industries, Ltd.) was diluted with ion-exchanged water to a phosphoric acid concentration of 3%, and a 3% aqueous lithium hydroxide solution (lithium hydroxide reagent was diluted with ion-exchanged water). Were mixed so that the molar ratio of phosphoric acid and lithium hydroxide was 1: 2 to prepare a 3% aqueous solution of dilithium hydrogen phosphate. A 3% aqueous solution of PVA 117 and a 3% aqueous solution of dilithium hydrogen phosphate were mixed so that each solid content was 100/20 (PVA / dilithium hydrogen phosphate) to prepare a second gas barrier coating composition. .
The thickness of the gas barrier layer after drying the second gas barrier coating composition on the first gas barrier layer using a Meyer bar is 0.
It was applied so as to have a thickness of 2 μm (applied amount of about 0.3 g / m ² ) and dried at 100 ° C. for 2 minutes to form a second gas barrier layer to obtain a gas barrier laminate.

Example 3 Polyethyleneimine (Epomin P-1000, an aqueous solution of 30% polyethyleneimine resin diluted to 3% with water) was added to the corona-treated surface of a biaxially stretched polypropylene film (thickness: 25 μm) to obtain a molecular weight. 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 (PVA
117, saponification degree 99%, completely saponified PVA, polymerization degree 1
A 3% aqueous solution of 700, manufactured by Kuraray Co., Ltd. was mixed so that the solid content mass ratio of polyethyleneimine and PVA was 10/90, and the resulting anchor paint (solid content 3%) was dried. The coating was applied so that the film thickness was 0.2 μm, and the coating was dried with a hot air dryer at 80 ° C. for 2 minutes to form an anchor layer. Then, the lithium silicate salt aqueous solution (solid content of Li ₂ O.SiO ₂ 4%) prepared in the same manner as in Example 1 was added to Example 2.
Synthetic smectite aqueous dispersion (solid content 2
%) Were 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. Aqueous ammonium tetraborate solution (solid content 3
%) Was prepared. The ratio of the solid content of ammonium tetraborate to the solid content of lithium silicate and synthetic smectite is 15/100 (the solid content of ammonium tetraborate is 15 parts by mass, the total solid content of lithium silicate and synthetic smectite is 1).
The above aqueous solution of ammonium tetraborate was added to a 3% aqueous solution of lithium silicate and synthetic smectite with stirring so that the amount became 100 parts by mass), and the mixture was further stirred for 30 minutes. Epoxy silane coupling agent (KB
M403, γ-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted with ion-exchanged water to obtain a 3% aqueous solution, and the solid content of the epoxy silane coupling agent, lithium silicate, and synthetic smectite Solids ratio is 2
It was added to 0/100 and further stirred to obtain a 3% aqueous solution to obtain a first gas barrier coating material. The first gas barrier coating composition was applied onto the anchor layer using a Meyer bar so that the thickness of the gas barrier layer after drying was 0.2 μm, and the coating was dried at 100 ° C. for 2 minutes. One gas barrier layer was formed. The second gas barrier coating composition of Example 1 was applied on the first gas barrier layer by a Meyer bar so that the film thickness after drying was 0.2 μm, and dried at 100 ° C. for 1 minute using a hot air dryer. did. The obtained OPP / anchor layer / first gas barrier layer / second gas barrier layer laminate was placed in a polypropylene bag and sealed, and the temperature was 40 ° C.
The mixture was heat-aged for 24 hours to obtain a gas barrier laminate.

<Example 4> An anchor layer and a first gas barrier layer were formed in the same manner as in Example 2. Using ion-exchanged water, polyvinyl alcohol (PVA 117, saponification degree 99
%, Completely saponified PVA, polymerization degree 1700, manufactured by Kuraray Co., Ltd.) was prepared. Separately, urea (H ₂ NCO
NH _2, molecular weight 60.1, melting point 132-136 ° C., diluted Wako Pure Chemical Co., Ltd., Ltd.) with ion-exchanged water to prepare a 3% aqueous urea solution. 3% aqueous solution of PVA 117 and 3 of urea
% Aqueous solution at each solid content of 100/20 (PVA /
Urea) to prepare a second gas barrier coating composition. The second gas barrier coating is applied on the first gas barrier layer using a Meyer bar so that the thickness of the gas barrier layer after drying is 0.2 μm (applied amount is about 0.3 g / m ² ). And dried at 100 ° C. for 2 minutes. The obtained OPP / anchor layer / first gas barrier layer / second gas barrier layer was placed in a polypropylene bag, sealed, and heat aged at 40 ° C. for 24 hours to obtain a gas barrier layered product. .

Example 5 Exactly the same as Example 4 except that ammonium carbonate ((NH ₄ ) ₂ CO ₃ , molecular weight 96.1, manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of urea. Then, a gas barrier laminate was obtained.

<Example 6> An anchor layer and a first gas barrier layer were formed in the same manner as in Example 2. Using ion-exchanged water, polyvinyl alcohol (PVA105, saponification degree 99
%, Completely saponified PVA, polymerization degree 500, manufactured by Kuraray Co., Ltd.) to prepare a 3% aqueous solution. Separately, boron oxide (B ₂
A 3% aqueous solution of boron oxide was prepared using O ₃ and Wako Pure Chemical Industries, Ltd. and ion-exchanged water. 3% of PVA105
A second gas barrier coating composition was prepared by mixing an aqueous solution and a 3% aqueous solution of boron oxide so that each solid content was 100/10 (PVA / boron oxide). The second gas barrier coating is applied on the first gas barrier layer using a Meyer bar so that the thickness of the gas barrier layer after drying is 0.2 μm (applied amount is about 0.3 g / m ² ). Work 10
It was dried at 0 ° C. for 2 minutes. Obtained OPP / anchor layer /
The laminated body composed of the first gas barrier layer / the second gas barrier layer is put in a polypropylene bag and sealed, and the mixture is kept at 40 ° C. for 24 hours.
It was heated and aged for a time 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 the second gas barrier layer was not provided.

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

<Comparative Example 3> A gas barrier laminate was obtained in exactly the same manner as in Example 2 except that the second gas barrier layer was not provided.

<Test Method> 1) Oxygen Permeability Measured under JIS-K-7126 B method (isobaric method) with the coated surface being the 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. Oxygen permeability is 50cc / ^{m 2} · 24
The time is preferably hr or less, more preferably 40 cc / m ² · 24 hr or less, still more preferably 30 cc / m ² · 24 hr or less. Further, the gas barrier laminate was allowed to stand for 72 hours under the conditions of 40 ° C. and 90% RH, and then the oxygen permeability was measured as described above (oxygen permeability after being left under high humidity conditions in the air). The oxygen permeability after being left under high humidity conditions is preferably 4 times or less than the oxygen permeability when not being left or 100 cc / m ² · 24 hr or less.

[0133]

[Table 1]

[0134]

EFFECTS OF THE INVENTION According to the present invention, a gas barrier having an excellent gas barrier property even under a high humidity condition in the atmosphere for a long period of time, preventing the white bloom phenomenon and being suitable as a packaging material. It has become possible to provide a functional laminate.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AA03B AA04B AA04C AA04H                       AA07B AA07C AA07H AA08B                       AA08C AA08H AA14B AA14C                       AA14H AA17 AA20B AC10B                       AC10C AH00C AK01C AK08B                       AK21 AK41 AK52B AR00B                       AR00C AT00A BA03 BA04                       BA07 BA10A BA10B BA10C                       CA13 EH46 EH462 EJ55                       EJ551 EJ86 EJ862 GB15                       JD02 JD02B JM01B JM02D                 4J002 AA001 AB011 AB041 BB221                       BE021 BE031 BG101 BG131                       CA001 CH021 CM011 DD017                       DE167 DF027 DG037 DH047                       DJ006 DJ007 DJ016 DK007                       EF037 EF077 EF097 EF117                       FD206 FD207 GF00 GG02                       GT00

Claims (10)

[Claims] 1. A gas barrier laminate having a gas barrier layer formed on at least one surface of a support, wherein the gas barrier layer is formed by sequentially laminating the following two layers from the support side. Barrier laminate. (1) A first gas barrier layer containing at least one silicic acid condensate selected from alkali metal silicates or colloidal silica. (2) A second gas barrier layer containing a high hydrogen-bonding resin and an acidic substance. 2. The silicic acid condensate has the general formula M ₂ O.nSiO.
The gas barrier property according to claim 1, wherein the gas barrier property is at least one selected from sodium silicate, potassium silicate, and lithium silicate represented by ₂ (n> 0, M = Na, K, Li). Laminate. 3. The acidic substance is at least one selected from a phosphoric acid compound, a sulfuric acid compound, a carbonic acid compound, and a boron compound.
The gas barrier laminate according to any one of 1. 4. The gas barrier laminate according to claim 1, wherein the gas barrier layer contains a tabular pigment. 5. The gas barrier laminate according to claim 4, wherein the tabular pigment is at least one selected from smectite clay and mica. 6. The gas barrier laminate according to claim 1, wherein the first gas barrier layer contains an acidic substance other than silicic acid. 7. The acidic substance other than silicic acid is a phosphoric acid compound,
The gas barrier laminate according to claim 6, which is at least one selected from a sulfuric acid compound, a carbonic acid compound, a nitric acid compound, and a boron compound. 8. The gas barrier laminate according to claim 1, wherein the gas barrier layer contains a hydrolysis-condensation product of a metal alkoxide having an organic functional group. 9. The gas barrier laminate according to any one of claims 1 to 8, wherein an anchor layer is present between the support and the gas barrier layer. 10. The gas barrier laminate according to claim 9, wherein the anchor layer contains at least one selected from a nitrogen-containing compound and a high hydrogen-bonding resin.