JP2790054B2 - Gas barrier laminate film and packaging material using this laminate film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier laminated film used in the field of packaging of foods, pharmaceuticals and the like, and a packaging material using the laminated film.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, pharmaceuticals, and the like have been used in order to suppress deterioration of contents, especially oxidation and deterioration of proteins and oils and fats in foods, and to maintain taste and freshness. In the case of medicines that need to be handled under aseptic conditions, the deterioration of the active ingredients is suppressed and the effects of oxygen, water vapor, and other gases that deteriorate the contents of the packaging material are prevented in order to maintain the efficacy. It is required to have a gas barrier property for blocking these gases.

For this reason, gas barrier properties such as polyvinyl alcohol (hereinafter referred to as PVA), ethylene vinyl alcohol copolymer (hereinafter referred to as EVOH), or polyvinylidene chloride resin (hereinafter referred to as PVDC) are generally relatively high. In general, a gas barrier film composed of a polymer resin composition referred to as "a" or a packaging film used for a packaging material as a gas barrier laminate by laminating or coating this polymer resin composition has been used. In addition, a suitable polymer resin composition (alone,
Vapor-deposited films in which a metal or metal compound such as Al is vapor-deposited on a film made of a film that does not have high gas barrier properties), for example, a silicon oxide (SiO _x ) thin film such as silicon monoxide (SiO), Magnesium oxide (Mg
O) A vapor-deposited film formed by forming a thin film on a substrate made of a polymer film having transparency by vapor deposition or the like, and has a gas barrier property superior to that of a gas barrier material composed of a polymer resin composition. The packaging film used for this packaging material has begun to be generally used, with little deterioration under high humidity.

[0004]

However, the above-mentioned PV
A, a film comprising an EVOH-based polymer resin composition,
Alternatively, a gas barrier laminate using a polymer resin composition has a large temperature dependency and a high humidity dependency, and thus has a reduced gas barrier property at high temperature or high humidity, and has no water vapor barrier property, and is not packaged. Depending on the use of, a gas barrier property may be significantly reduced when a boiling treatment or a retort treatment is performed. The gas barrier laminate using a PVDC-based polymer resin composition has low humidity dependency,
There is a problem that it is difficult to realize a high gas barrier material (high gas barrier material) having an oxygen barrier property of 1 cm ³ / m ² · day · atm or less. In addition, since the coating contains a large amount of chlorine, there is a problem in terms of waste disposal such as incineration and recycling.

Further, the above-mentioned metal vapor-deposited film, a silicon oxide thin film such as silicon monoxide (SiO), and a vapor-deposited film on which a magnesium oxide (MgO) thin film is vapor-deposited have a thin film of an inorganic compound used for a gas barrier layer. It is chipped, is susceptible to rubbing and bending, and has poor adhesion to the substrate, so care must be taken in handling, especially when printing, laminating, post-processing packaging materials such as bag making, cracking the thin film. There is a problem that the gas barrier property is generated and the gas barrier property is significantly reduced. In addition, a vacuum deposition method, a sputtering method,
Since it is formed using a vacuum process such as plasma enhanced chemical vapor deposition, the equipment is expensive, and the temperature is locally high during the formation process, causing damage to the base material or adding a low molecular weight part or a plasticizer. Defects, pinholes, etc. may be generated in the inorganic thin film due to decomposition and degassing of the agent part, etc., and high gas barrier properties cannot be achieved by processing of packaging materials, and the cost becomes expensive. have.

For this reason, Japanese Patent Application Laid-Open No.
As described in Japanese Patent No. 295931, a gas barrier material in which a metal alkoxide coating is directly formed on a substrate made of a plastic film has been proposed. Since this gas barrier material has a certain degree of flexibility and can be manufactured by a liquid phase coating method, the cost can be reduced.

However, the above-mentioned gas barrier material has improved gas barrier properties as compared with the case of a single plastic film substrate, but cannot be said to have sufficient gas barrier properties.

Further, as described in JP-A-5-9317, as a method for producing a resin molded article provided with a gas barrier property, a vapor-deposited thin film of silicon oxide (SiO _x ) is formed on a plastic film substrate. , S on the deposited thin film
A method has been proposed in which a mixed solution of iO ₂ particles and a water-soluble resin or an aqueous emulsion is coated and then dried. Resin molded article according to this manufacturing method, when the deformation caused by external stress, suppressing the microcracks spread mixed layer of SiO ₂ particles and a resin coated on the SiO _x deposited on the thin film occurs SiO _x deposited film, cracks By protecting the portion, it is possible to suppress a decrease in gas barrier properties. However, a resin molded article comprising the structure, reducing the spread of micro-cracks occurring in the SiO _x deposited film, albeit the effect of suppressing the lowering of gas barrier properties, the effect is only to its role as a protective layer just deposited film Absent. The gas barrier property of the resin molded product having the above-described structure indicates the gas barrier property of a vapor-deposited film in which a vapor-deposited thin film is simply formed on a substrate because a coating layer formed on the vapor-deposited layer is simply a mixed film of SiO ₂ particles and a resin. And it was impossible to obtain a higher gas barrier property.

Accordingly, the present invention provides a gas barrier laminate film which is flexible, has excellent gas barrier properties against oxygen, water vapor, etc., has heat resistance, moisture resistance, water resistance, and is easy to manufacture, and a laminate film thereof. An object of the present invention is to provide a packaging material using the same.

[0010]

According to the first aspect of the present invention,
A vapor-deposited layer made of an inorganic compound is used as a first layer on a base material made of a polymer resin composition, and a water-soluble polymer and (a) one or more alkoxides and / or a hydrolyzate thereof or (b) chloride A gas barrier laminate film comprising a gas barrier coating film formed by applying a coating agent mainly composed of an aqueous solution containing at least one of tin or a water / alcohol mixed solution and drying by heating, as a second layer. It is.

According to a second aspect of the present invention, there is provided a gas barrier laminate according to the first aspect, wherein an anchor coat treatment is performed on a substrate made of a polymer resin composition to provide a vapor deposited layer made of an inorganic compound. Film.

According to a third aspect of the present invention, there is provided a gas barrier laminated film according to the first aspect of the present invention, wherein the water-soluble polymer is polyvinyl alcohol.

According to a fourth aspect of the present invention, based on any one of the first to third aspects, the alkoxide is tetraethoxysilane or triisopropoxyaluminum, or a mixture thereof. It is a characteristic gas barrier laminated film. According to a fifth aspect of the present invention, based on any one of the first to fourth aspects of the present invention, the inorganic compound forming the vapor deposition layer has a gas barrier property of one of aluminum oxide, magnesium oxide, and silicon oxide. It is a laminated film. According to a sixth aspect of the present invention, there is provided a packaging material characterized in that a heat-sealable thermoplastic resin is laminated on the surface of the gas barrier film according to any one of the first to fifth aspects. According to a seventh aspect of the present invention, there is provided a packaging material according to the sixth aspect, wherein a heat-sealable thermoplastic resin is laminated on the gas barrier coating surface via an adhesive layer. The invention according to claim 8 is the invention according to claim 6 or claim 7.
A packaging material used for packaging boil and food for sterilizing retorts, based on the invention described in (1).

[0014]

According to the present invention, a vapor-deposited layer made of an inorganic compound is used as a first layer on a substrate made of a polymer resin composition, and a water-soluble polymer and (a) one or more alkoxides and / or A gas barrier coating formed by applying an aqueous solution containing at least one of the hydrolyzate and (b) tin chloride or a water / alcohol mixed solution as a main component and drying by heating is laminated as a second layer. By doing
The second layer contains a highly reactive inorganic component, and since the composite coating with the water-soluble polymer has excellent gas barrier properties, a reaction layer of both layers is formed at the interface between the first layer and the second layer, or Second
The layer fills and reinforces defects or micropores such as pinholes, cracks, and grain boundaries that occur in the first layer, so that a dense structure is formed. Thus, the layer has high gas barrier properties, water resistance, moisture resistance, and deformation. It has the flexibility to endure.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail. FIG. 1 is a schematic diagram illustrating the configuration of the gas barrier laminate of the present invention.

In FIG. 1, reference numeral 1 denotes a gas barrier laminate, 2 denotes a substrate, 3 denotes a first inorganic vapor deposition layer, and 4 denotes a second gas barrier coating layer. The base material 2 is in the form of a sheet or a film, and is composed of polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (Neylon-6, nylon-66, etc.). , Polyvinyl chloride, polyimide, or a copolymer of these polymers, such as those commonly used as packaging materials can be used. The base material is appropriately selected from the above materials depending on the application.

The polymer resin material used for the substrate 2 includes, for example, an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant,
Known additives such as a coloring agent can be added, and are appropriately added as needed.

Further, the surface of the substrate 2 may be subjected to a surface modification such as a corona treatment or an anchor coating treatment to improve the adhesion of the coating.

The inorganic vapor-deposited layer 3, which is the first layer, is made of an oxide, nitride, or fluoride such as silicon, aluminum, titanium, zirconium, tin, or magnesium, or a composite thereof, and is formed by a vacuum vapor deposition method. It is formed by a vacuum process such as a sputtering method and a plasma vapor deposition method (CVD method). In particular, aluminum oxide is colorless and transparent,
It has excellent properties such as boil and retort resistance and can be used for a wide range of applications.

The thickness of the inorganic vapor-deposited layer 3 varies depending on the application and the thickness of the second layer, but is preferably in the range of several tens of degrees to 5000 degrees. However, if it is less than 50 degrees, there is a problem in the continuity of the thin film.
On the other hand, if it exceeds 3000 °, cracks are liable to occur and the flexibility is lowered.

The gas barrier coating layer 4 as the second layer contains a water-soluble polymer and at least one of (a) an alkoxide of at least one metal or the like and / or a hydrolyzate thereof or (b) tin chloride. It consists of a coating agent whose main component is an aqueous solution or a water / alcohol mixed solution. A solution prepared by dissolving a water-soluble polymer and tin chloride in an aqueous (water or water / alcohol mixture) solvent, or a solution prepared by directly or preliminarily hydrolyzing an alkoxide such as a metal into the solution. It is formed by coating, heating and drying the inorganic thin film layer 3 on the base material 2. Each component contained in the coating agent will be described in detail below.

The water-soluble polymer used for the coating agent in the present invention includes polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate and the like. In particular, polyvinyl alcohol (hereinafter referred to as PVA) of the present invention is used. When used as a coating agent for a gas barrier laminate, the gas barrier properties are most excellent. PVA here is
Generally obtained by saponifying polyvinyl acetate, so-called partially saponified PVA in which acetic acid groups remain for several tens%.
Completely saponified PVA with only a few percent of acetic acid groups remaining
, Including but not limited to

Tin chloride is stannous chloride (SnCl ₂ ),
Stannic chloride (SnCl ₄ ) or a mixture thereof may be used, and either anhydrous or hydrated can be used.

The alkoxide is an alkoxide of a metal or the like, tetraethoxysilane [Si (OC ₂ H ₅ )].
₄ ], triisopropoxy aluminum [Al (O-
2′-C ₃ H ₇ ) ₃ ]; M (OR) n (M: metal such as Si Ti Ai Zr); R: CH
₃ , alkyl groups such as C ₂ H ₅ ). Among them, tetraethoxysilane and triisopropoxyaluminum are preferable since they are relatively stable in an aqueous solvent after hydrolysis.

Each of the above-mentioned components can be added to the coating agent alone or in combination of several components. Further, as long as the barrier properties of the coating agent are not impaired, isocyanate compounds, silane coupling agents, dispersants, and stabilizers Known additives such as a viscosity modifier and a colorant can be added.

For example, an isocyanate compound added to a coating agent has two or more isocyanate groups (NCO groups) in its molecule. For example, tolylene diisocyanate (hereinafter referred to as TDI), triphenylmethane triisocyanate (Hereinafter, referred to as TTI), tetramethylxylene diisocyanate (hereinafter, referred to as TTI)
TMXDI), and polymers and derivatives thereof.

As a method for applying the coating agent, conventionally known means such as a dipping method, a roll coating method, a screen printing method, and a spray method, which are usually used, are used. The thickness of the film varies depending on the type of the coating agent, but the thickness after drying may be in the range of about 0.01 to 100 μm. When the thickness is 50 μm or more, cracks are easily generated in the film. It is desirable that the thickness be 50 μm.

Although the details are not clear in many places, any reaction layer is formed between the inorganic vapor-deposited layer 3 as the first layer and the coating made of the coating agent as the second layer, or The second layer fills and reinforces defects or micropores such as pinholes, cracks and grain boundaries generated in the first layer, thereby forming a dense structure, which improves gas barrier properties and is the first layer of the deposited thin film layer. Plays a role as a protective layer. Further, since the composition of the coating agent is mainly composed of an inorganic component such as an alkoxide such as a metal or tin chloride and a water-soluble polymer such as PVA, gas barrier properties can be improved. That is, an inorganic component such as an alkoxide such as a metal or tin chloride is hydrolyzed and polycondensed in a solution to form a chain or three-dimensional dendritic polymer, and the polymerization proceeds further by evaporating the solvent upon drying and heating. , A highly reactive inorganic component,
It is considered that a water-soluble polymer forms a complex at the molecular level. Therefore, they are different from fine particles such as silica (SiO ₂ ) having a specific particle diameter or silica sol (colloidal silica) obtained from sodium silicate (water glass) in which fine particles are simply dispersed.

Further, on the gas barrier laminate film of the present invention, if necessary, a thermoplastic resin layer and a printing layer which can be heat-sealed are laminated on the gas barrier coating layer or the base material 2 to form a packaging material. It is also possible to laminate a plurality of resins via an adhesive layer to form a packaging material.

The gas barrier laminate film of the present invention and a packaging material using the laminate film will be described with reference to specific examples.

Example 1 A 12 μm-thick polyethylene terephthalate (hereinafter referred to as P
ET) as a base material, a thin film layer having a thickness of 400 mm is formed on the upper surface thereof by a vacuum deposition method using an electron beam heating method with a deposition source of SiO (silicon oxide), The coating agent mixed in the above ratio was applied by a bar coater and dried at 120 ° C. for 1 minute with a drier to form a film having a thickness of about 0.3 μm, thereby obtaining a gas barrier laminated film.

(Components of Coating Agent) (A) Tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ :
Hereinafter, referred to as TEOS] 10.4 g of hydrochloric acid (0.1 N)
89.6 g was added, and the mixture was stirred for 30 minutes and hydrolyzed to obtain a hydrolyzed solution having a solid content of 3 wt% (in terms of SiO2). (B) Triisopropoxy aluminum [Al (O-
2′-C ₃ H ₇ ) ₃ : hereinafter referred to as TPA] after dissolving 6.0 g in 90 g of hot water at 80 ° C., and then adding 4 g of hydrochloric acid (5N).
3 wt% solid content (calculated as Al ₂ O ₃ )
(C) 3 wt% water / ethanol solution of stannous chloride (anhydride) (50:50 by weight ratio of water: ethanol) (D) 3 wt% aqueous solution of stannic chloride (anhydride) (E) 3.0 wt% water / isopropyl alcohol solution of polyvinyl alcohol (90:10 in water: isopropyl alcohol weight ratio) (F) 3 wt% water / ethanol solution of polyvinyl pyrrolidone (50:50 in water: ethanol weight ratio) (G) Water-based gravure ink (acrylic) Use only water-based vehicle. Acrylic resin solid content 10 wt% water / ethanol solution (water: ethanol weight ratio 50:50) (H) 3.0 w of silica fine particles (average particle size 0.1 μm)
t% aqueous dispersion (I) 3.0 wt% silica sol solution obtained by diluting silica sol (trade name: Snowtex, manufactured by Nissan Chemical Industries, Ltd.) with water

(Composition of Coating Agent) 1 (A) / (E) Mixing ratio (wt%) 60/40 2 (A) / (B) / (F) compounding ratio (wt%) 50/10/40 3 (C) / (E) Compounding ratio (wt%) 60/40 4 (A) / (C) / (E) compounding ratio (wt%) 40/30/30 No. 5 (A) / (D) / (E) compounding ratio (wt%) 40/30/30 Comparative Example No. 5 6 No coating Compounding ratio (wt%) Comparative Example No. 7 (E) Compounding ratio (wt%) 100 Comparative Example No. 8 (F) Compounding ratio (wt%) 100 Comparative Example No. 9 (G) Compounding ratio (wt%) 100 Comparative Example No. 9 10 (H) / (E) Compounding ratio (wt%) 60/40 Comparative Example No. 11 (I) / (E) compounding ratio (wt%) 60/40

The obtained gas-barrier laminated film was treated with 40
The samples were stored for 4 weeks under a constant temperature and humidity of 90 ° C.-90% RH, and gas barrier properties before and after the storage were evaluated by measuring oxygen permeability and water vapor permeability. The oxygen barrier property is measured using an oxygen permeability measuring device (MOCON OXTRAN 10 / 40A manufactured by Modern Control Co., Ltd.) in a 25 ° C.-100% RH atmosphere, and the water vapor barrier property is measured in a 40 ° C.-90 RH atmosphere. Equipment (PE manufactured by Modern Control)
RMATRAN W6), and the results are shown in Table 1. As a comparative example, a laminated film composed of a film of only a vapor-deposited film without a coating, a film of only a water-soluble polymer, and a film of only an aqueous ink, mixed with a water-soluble resin using silica fine particles or silica sol instead of metal alkoxide. A laminated film composed of a coating was prepared and similarly measured and evaluated.

[0035]

[Table 1]

From these, those obtained by applying a coating agent to a vapor-deposited film (Nos. 1 to 5) have the oxygen barrier property and the water vapor barrier property both of No. 1 having no coating. 6 and showed high gas barrier properties. The water-soluble polymers (Nos. 7 and 8) and the aqueous inks (No. 9) of Comparative Examples slightly improved gas barrier properties, but showed a decrease in gas barrier properties after storage under high humidity. Further, a mixed coating with a water-soluble resin using silica fine particles or silica sol (No. 1)
Nos. 0 and 11) are Nos. Without coating. No improvement in gas barrier properties was observed as compared with No. 6, which was inferior to the case where the alkoxide of the gas barrier laminate film of the present invention was used, and clearly shows a difference due to the constitution.

[Second embodiment] 1, No. 4, no. 6, no. The laminated surface of the laminated film No. 9 was bonded to an unstretched polypropylene (CPP, 30 μm) film with a polyol-isocyanate-based adhesive using the coated surface of the laminated film as an adhesive surface to produce a laminated film, thereby obtaining a gas barrier laminated film. The measurement of oxygen permeability and water vapor permeability and the measurement of adhesive strength were performed and evaluated. The measurement of the adhesive strength is 15 mm width, T-peel, 3
The test was performed under the condition of 00 mm / min. Table 2 shows the results. As a comparative example, PET without a deposited film was used.
The same measurement and evaluation were performed on a laminated film formed by coating a film and forming a film having a thickness of 0.3 μm.

[0038]

[Table 2]

According to this, while the packaging material of the present invention has a high oxygen barrier property and a high water vapor barrier property, a film made of the coating agent used for the second layer of the present invention was directly formed on a substrate. Although the packaging material has excellent oxygen barrier properties, it has low water vapor barrier properties. By providing a vapor-deposited film on the substrate, it was possible to obtain a high oxygen barrier property and a high water vapor barrier property that could not be obtained individually. In addition, the adhesive strength was remarkably improved as compared with the film without the deposited film.

[Third Embodiment] In the second embodiment, as shown in FIG. 13, No. 16, No. CP to 18
After performing a predetermined elongation tensile test on the laminated film obtained by laminating P using a tensile tester, measurement of oxygen permeability and water vapor permeability and evaluation of flexibility were performed. Table 3 shows the results.
Shown in

[0041]

[Table 3]

The film of the comparative example having only the vapor-deposited film (No. 1)
6) is a few percent elongation, cannot withstand deformation due to tension, causes cracks in the film, and gas barrier properties are significantly reduced.
The gas barrier laminate film of the present invention (No. 13)
Deterioration is hardly recognized up to about 0%, and the deterioration is small even by deformation due to subsequent pulling, and has considerable flexibility as compared with the laminated film of the vapor deposition film alone of the comparative example. Further, the laminated film (No. 18) of the water-based gravure ink of the comparative example also starts to be deformed by stretching at several percent elongation, and the effect is slight, although some suppression of deterioration is recognized.

Example 4 A PET film (12 μm) was used as a base material, and on one side thereof, Al ₂ O ₃ , SnO ₂ , and MgO were used as vapor deposition sources, and a film thickness of 400 Å was formed by a vacuum vapor deposition method using an electron beam heating method.
Is formed, and the N layer of Example 1 is formed on the thin film layer.
o. Using the coating agent No. 4, a coating film was formed in the same manner as in Example 1, and the measurement and evaluation of oxygen permeability and water vapor permeability were performed. As a comparative example, a sample having only the thin film layer and no coating was similarly measured and evaluated. Table 4 shows the results.

[0044]

[Table 4]

From these results, it was found that Al ₂ O ₃ , SnO ₂ , M
Since a gas barrier property is significantly improved by a coating (coating) using a coating agent formed on a vapor-deposited thin film layer made of gO, the effect of the coating of the gas barrier laminated film having the configuration of the present invention is apparent.

Example 5 A PET film (12 μm) was used as a base material, and in the same manner as in Examples 1 and 4, SiO and Al ₂ O ₃ were used as an evaporation source on one side by a vacuum evaporation method using an electron beam heating method. A thin film layer having a thickness of 400 ° was formed, and No. 1 of Example 1 was formed on this thin film layer. Using the coating agent No. 4, a coating was formed in the same manner as in Example 1. Further, a CCP film (60 μm) is formed through an adhesive layer made of a polyol-isocyanate-based adhesive.
m) was adhered and laminated to obtain a packaging material. Using this packaging material, a 200 mm × 150 mm pouch was produced, and 200 cc of water was enclosed as the contents. This was subjected to a retort treatment (120 ° C. for 20 minutes), and an oxygen permeability before and after the treatment was measured and a laminate strength was evaluated. In addition, as a comparative example, a sample having only a thin film layer and no coating was similarly measured and evaluated. Table 5 shows the results.

[0047]

[Table 5]

From these results, it is found that the packaging material using the gas barrier laminate film of the present invention in which a coating using a coating agent is formed on a vapor-deposited thin film layer is prevented from being deteriorated in gas barrier properties and deterioration in adhesive strength due to retort treatment. You.

[0049]

As described above, the gas barrier laminate film of the present invention and the packaging material using this laminate film are obtained by forming a vapor-deposited layer made of an inorganic compound on a base material made of a polymer resin composition. And a water-soluble polymer and (a) 1
A gas barrier coating obtained by applying a coating agent mainly composed of an aqueous solution containing at least one or more alkoxides and / or hydrolysates thereof or (b) tin chloride or a mixed solution of water / alcohol, and drying by heating. Are laminated as a second layer, thereby having high gas barrier properties and excellent flexibility, lamination strength, water resistance and moisture resistance. Further, the packaging material using the gas barrier laminated film has excellent resistance to boiling and retort, and even if laminated with another resin, the strength is sufficiently enduring practical use. That is, even under a high-temperature and high-humidity atmosphere, long-term storage is possible without impairing the gas barrier properties and without deteriorating contents such as foods and pharmaceuticals. Further, the present invention has an effect that gas barrier properties are not impaired even in post-processing such as printing, laminating, and bag making as a packaging material.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating the configuration of a gas barrier laminate film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas barrier laminated film 2 Substrate 3 Inorganic vapor deposition layer 4 Gas barrier coating layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-295931 (JP, A) JP-A-1-184127 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 C08J 7/04-7/06

Claims (8)

(57) [Claims] 1. A method according to claim 1, wherein a vapor-deposited layer made of an inorganic compound is used as a first layer on a substrate made of a polymer resin composition,
An aqueous solution containing at least one of (a) one or more alkoxides and / or a hydrolyzate thereof and (b) tin chloride, or a coating agent mainly containing a water / alcohol mixed solution is applied and dried by heating. A gas-barrier laminated film characterized in that a gas-barrier coating is laminated as a second layer. 2. The gas barrier laminate film according to claim 1, wherein an anchor coat treatment is performed on the substrate made of the polymer resin composition to provide a vapor deposited layer made of an inorganic compound. 3. The gas barrier laminate film according to claim 1, wherein the water-soluble polymer is polyvinyl alcohol. 4. The gas barrier laminate film according to claim 1, wherein the alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof. 5. The gas barrier laminate film according to claim 1, wherein the inorganic compound forming the vapor deposition layer comprises one of aluminum oxide, magnesium oxide and silicon oxide. 6. A packaging material, wherein a heat-sealable thermoplastic resin is laminated on the gas-barrier coating surface according to any one of claims 1 to 5. 7. The packaging material according to claim 6, wherein a heat-sealable thermoplastic resin is laminated on the gas barrier coating surface via an adhesive layer. 8. The packaging material according to claim 6, which is used for packaging foods for sterilizing boil and retort.