JP2001162716A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film excellent in transparency and disposal properties and reduced in the deterioration caused by humidity. SOLUTION: A gas barrier film 120 based on alkali metal polysilicate represented by M2O.nSi2 (wherein M is lithium or a plurality of alkali metals including lithium and n is a molar ratio of 1-20), a nitrogen compound and a water-soluble polymer is laminated on at least the single surface of a base material 110 and a protective layer 130 based on metal alkoxide, a silane coupling agent or hydrolysates of them is further provided on the film 120.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a gas barrier film. More specifically, the present invention relates to a gas barrier film suitable as a packaging film for preventing foods, pharmaceuticals, electronic members, electronic devices, optical members, and the like from being deteriorated or deteriorated by oxygen, water vapor, or the like.

[0002]

2. Description of the Related Art Various functions are required for packaging materials.
Deterioration and deterioration of the contents are promoted mainly by the influence of oxygen, moisture, light, heat and the like. In particular, the influence of oxygen and moisture is great, and it is important to block them from the viewpoint of protecting the contents. That is, the presence of a high-performance gas barrier film is required. In addition, under the circumstances where tastes are diversified and various additives are subject to laws and regulations as in today, not only shielding from the outside but also inert gas filling packaging, deterioration of flavor and aroma It is necessary to block transmission from inside to outside, such as prevention.

[0003] However, plastic films generally have poor gas barrier properties by themselves, and in particular, some plastic films that retain gas barrier properties even under high humidity are not excluded. Some examples include chlorine-containing polymers such as polyvinylidene chloride, which are suspected to generate harmful dioxins during incineration, etc., and are not always optimal. Hard to say. Therefore, a method of producing a gas barrier film by laminating another layer having excellent gas barrier properties has been adopted.

[0004] As a material of the gas barrier layer which is effective even under high humidity, there is an example of using silicon oxide derived from hydrolyzing tetraethoxysilane and then thermally condensing it. However, this method generally requires a high temperature. It is a great barrier for laminating on plastic film. Further, a gas barrier film derived from an alkali metal polysilicate has been devised as a material which can be manufactured by low-temperature drying, but humidity deterioration is inevitable. In addition, humidity degradation,
As a gas barrier film having no humidity dependency, a method of applying an emulsion of a chlorine-containing polymer may be mentioned.
As mentioned above, there is a major problem with disposability.

[0005]

A gas barrier film which is transparent, excellent in disposability, and has little deterioration in humidity or humidity is not manufactured at present. The present invention solves the above problems and provides a gas barrier film that is transparent, has excellent disposal properties, and has little humidity deterioration.

[0006]

Means for Solving the Problems The present invention is a result of intensive studies to solve the above-mentioned problems, and the first invention of the present invention comprises at least a substrate (110) as shown in FIG. On one surface, M ₂ O.nSiO ₂ (M is lithium or a plurality of alkali metals containing lithium, n is 1 to 20 in molar ratio)
A gas barrier coating (120) composed mainly of an alkali metal polysilicate represented by the formula (1), a nitrogen compound and a water-soluble polymer, and further thereon a metal alkoxide and / or a silane coupling agent or a silane coupling agent thereof. A gas barrier film (100) comprising a protective layer (130) containing a hydrolyzate as a main component.

Next, a second invention of the present invention is the gas barrier film according to the first invention, wherein the nitrogen compound is an amino group-containing silane coupling agent.

Next, a third invention of the present invention is characterized in that the water-soluble polymer is a saccharide, polyvinyl alcohol, polyethyleneimine or a derivative thereof.
The gas barrier film according to the first or second aspect of the present invention.

Next, according to a fourth aspect of the present invention, the weight ratio of SiO ₂ component / (nitrogen compound + water-soluble polymer) in the gas barrier coating is 50/50 to 99.99 / 0.01.
The gas barrier film according to any one of the first to third inventions, wherein

Next, a fifth invention of the present invention is characterized in that the metal of the metal alkoxide of the protective layer contains at least one of silicon, titanium, aluminum, zirconium and niobium. A gas barrier film according to a fourth aspect.

Next, a sixth invention of the present invention is characterized in that said metal alkoxide contains at least one of tetraethoxysilane, tetramethoxysilane and a polymer thereof. It is a gas barrier film as described in the invention of Claim 5.

Next, a seventh aspect of the present invention is the gas barrier film according to the first to sixth aspects, wherein the silane coupling agent of the protective layer has an epoxy group. It is.

Next, an eighth invention of the present invention is characterized in that a Lewis acid is added to a mixture containing a metal alkoxide or a hydrolyzate thereof when forming the above-mentioned protective layer. It is a gas barrier film as described in 7th invention.

Next, a ninth aspect of the present invention is the first to eighth aspects, wherein the Lewis acid contains at least one compound selected from the group consisting of tin, titanium, aluminum, boron and zinc. It is a gas barrier film according to the invention.

Next, a tenth aspect of the present invention is the gas barrier film according to the first to sixth aspects, wherein the silane coupling agent of the protective layer has an isocyanate group. It is.

In an eleventh aspect of the present invention, the base material is a plastic film made of a plastic material or a plastic material subjected to a surface modification treatment. It is a gas barrier film according to the invention.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail.
First, the gas barrier coating layer will be described. The term “alkali metal polysilicate” used herein means particularly lithium polysilicate Li ₂ O.
nSiO ₂ is an essential component, but it is also possible to combine inexpensive sodium polysilicate or water-resistant potassium silicate, and to reduce the price, improve water resistance and improve stability over time without impairing the gas barrier function of lithium polysilicate. It is possible to obtain an alkali metal polysilicate having such characteristics as described above. When an alkali metal other than lithium is added, Li ₂₀ / M ′ ₂ O (m ′: alkali metal other than lithium) is preferably 0.5 (molar ratio) or more in consideration of maintaining gas barrier properties. However, the present invention is not limited to this.

It has long been known that lithium polysilicate is useful as a gas barrier material, particularly as a material for improving oxygen barrier properties. However, when a film is formed on a plastic film using only lithium polysilicate, the molar ratio represented by Li ₂ 0 · nSiO ₂ becomes n
If it is not within the range of ≦ 5, a film cannot be formed, and n ≦ 5
Lithium polysilicate coatings formed in the above range also have a sudden shrinkage due to drying during film formation and the coating itself lacks flexibility, so it cannot follow a flexible plastic substrate unless it is dried slowly at low temperature for a long time. In addition, damages such as cracks (cracks) occur, and the oxygen barrier property is reduced.

Further, even if lithium polysilicate is used alone, a further improvement in gas barrier properties can be expected if drying is performed at a high temperature of 120 ° C. or higher, as in other sol-gel methods. However, the plastic material as a base material is limited.
Since the shrinkage of the dry film itself is very large, it is practically difficult. By introducing sodium, potassium, calcium, magnesium, sulfur, phosphorus, nitrogen, etc. as a method of imparting a water vapor barrier property by drying at a low temperature, the densification of the silicon oxide film is promoted and the water vapor barrier property is improved. Since the base material is a plastic material, nitrogen is introduced by nitrogen compounds such as amines, which are organic components, because of problems such as adhesion, flexibility, safety in the case of scattering, and prevention of elution in the case of moisture absorption. Is most preferred.

As a method for introducing nitrogen into the lithium polysilicate, a gas introduction method in which dry nitrogen gas or ammonia gas is substituted and the solution is permeated into an aqueous solution by heating, pressurizing, or the like, or a solid or liquid material at room temperature which is directly alkali silicate. Although there is a method of dissolving in an aqueous solution, the latter is characterized in that it can be dissolved and diffused with a simple stirring device, and that the amount of nitrogen introduced can be easily controlled. The nitrogen compound includes ammonia, halogenoamine, dihalogenoamine,
Nitrogen halide, metal amide, metal imide, metal nitride, amines, ammonium salt, alkyl ammonium salt, dialkyl ammonium salt, trialkyl ammonium salt, tetraalkyl ammonium salt, hydrogen azide,
Metal azide, hydrazine, hydradium salt, hydroxylamine, hydroxylammonium salt, nitrate, hyponitrite, nitroxylate, nitrite, peroxonitrite, peroxonitrate, nitrogen halide, nitrosyl halide, nitrile halide, halogen nitrate , Cyanide, cyanate, thiocyanate, phosphorus nitride, nitrogen sulfide or their derivatives, etc., but they have stability, safety, environmental friendliness, price, compatibility with alkali silicate aqueous solution, film strength, Considering flexibility, prevention of shrinkage, etc., amines that can be easily dissolved in an alkaline aqueous solution and can introduce a highly flexible hydrocarbon residue are more preferable,
Further considering the interaction with lithium silicate,
It preferably has an alkoxysilyl group.

The above-mentioned amines are compounds in which a hydrogen atom of ammonia is substituted with a hydrocarbon residue, and the amino group (N
There are a primary amine having H ₂ —), a secondary amine having an imino group (—NH—), a tertiary amine and a quaternary ammonium salt in which all hydrogens are substituted, and a polyamine having many of these functional groups. Also included are ethyleneimine-based polymers such as polyethyleneimine, aminoethylated resins, and aziridinyl group-containing compounds. As an amino group-containing silane coupling agent which is a monoamine or a diamine having an alkoxysilyl group, N- (2-aminoethyl) 3
-Aminopropylmethyldimethoxysilane, N- (2-
Aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and the like. Before introduction, they may be hydrolyzed and silanolized in an aqueous solution before introduction.

The above-mentioned water-soluble polymer is a polymer having a hydroxyl group, a carboxyl group, an amino group or a polyether bond, and needs to be water-soluble in consideration of compatibility with an aqueous alkali metal polysilicate solution. . For example, polyvinyl alcohol or its derivatives, polyethyleneimine or its derivatives, ethylene-vinyl alcohol copolymer, polysaccharides (including oligosaccharides and oligosaccharides) represented by amylose and cellulose, polyacrylic acid and polymethacrylic acid Alternatively, a copolymer thereof, polyethylene glycol, polyoxyethylene, or the like can be used. Further, in consideration of compatibility with alkali metal silicate, gas barrier properties, it is preferable to have a weakly acidic to strongly alkaline property, and polysaccharides, polyvinyl alcohol, polyethyleneimine, polyethylene glycol, polyoxyethylene and the like, or derivatives thereof. However, the present invention is not limited to this example. In addition, regarding the water-soluble polymer, for saccharides, in consideration of the film-forming properties and flexibility of the gas barrier film, amylose and cellulose belonging to the polysaccharide in which glucose is polymerized, and their derivatives. preferable. The polyvinyl alcohol refers to a polymer obtained by polymerizing and saponifying a carboxylic acid vinyl ester (particularly, vinyl acetate in general), which is a main raw material. The polyvinyl alcohol used in the present invention includes a gas barrier coating film. In consideration of the composition, flexibility, water resistance, mechanical strength, water solubility with alkali metal polysilicate, etc., those having a degree of polymerization of 300 to 3000 and a degree of saponification of 95 mol% or more are more preferable. In addition, polyvinyl alcohol derivatives include:
Modified polyvinyl alcohol in which silanol groups, carboxyl groups, amino groups, sulfonic acid groups, acetoacetyl groups, etc. are introduced at 10 mol% or less by copolymerizing and modifying hydroxyl groups and hydroxyl groups at 10 mol% or less, formalization, acetalization, butyral Although modified polyvinyl alcohols and the like are included, these can be selected or mixed in two or more types depending on the compatibility with the alkali metal polysilicate, the adhesion to the plastic substrate, and the like. The above-mentioned polyethyleneimine is a polyamine having a branched structure with primary, secondary and tertiary amino groups using ethyleneimine as a starting material. Particularly, those having a molecular weight of 300 to 100,000 are suitable for use in the present invention. .

The method of mixing (A) the alkali metal polysilicate with (B) the nitrogen compound and (B) the water-soluble polymer can be a known method, and is not particularly limited.
The mixing ratio is determined by considering the gas barrier properties, flexibility, water resistance, etc., and the SiO ₂ component in (A) / (B) = 50/5.
It is preferably in the range of 0 to 99.99 / 0.01 (weight ratio). When (B) is 50% by weight or more, the gas barrier property is reduced due to moisture absorption of a nitrogen compound or a water-soluble polymer, and when it is 0.01% by weight or less, an effect of suppressing shrinkage during formation of an alkali metal polysilicate coating is obtained. Also, even if a film is formed, it is not excellent in mechanical strength.

As a method for forming the gas barrier film, a usual wet coating method can be used. For example, dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, gravure offset, and the like can be used. The coating is applied to one or both surfaces of the substrate by using these coating methods. A drying method for drying may be a known and commonly used drying method such as hot air drying, hot roll drying, and infrared irradiation, and is not particularly limited.

The thickness of the gas barrier coating is generally preferably in the range of 0.01 to 100 μm, more preferably 0.01 to 10 μm, after drying. . When the thickness is less than 0.01 μm, it is difficult to obtain a uniform film. On the other hand, when the thickness exceeds 10 μm, cracks tend to occur in the film, which is not economically preferable.

Next, the protective layer will be described. Here, the metal alkoxide is a substance represented by the general formula M ″ (OR) _M , where R is a general alkyl group. M ″ is a variety of metals having a valence of m, but is not limited to those used in a general sol-gel method, and silicon, aluminum, titanium, zirconium, niobium and the like are particularly preferable.

The silane coupling agent is the same as the above-mentioned one.
General formula R₁R_TwoR_Three..R_n(OR) _mnSubstance represented by
And R₁R_TwoR_Three.. is an alkyl group or various functional groups
It is a hydrocarbon group having a group. Especially with epoxy group
Are preferred, especially 2- (3,4-epoxy)
(Cyclohexyl) trimethoxysilane, 2- (3,4
-Epoxycyclohexyl) triethoxysilane, 5,
6-epoxyhexyltriethoxysilane, 3-glyci
Doxypropyltrimethoxysilane, 3-glycidoxy
Propyltriethoxysilane, 3-glycidoxypropyl
Such as methyldimethoxysilane is good,
It is not limited.

Various Lewis acid catalysts may be added as catalysts capable of contributing to the ring opening reaction of the epoxy group. Tin chloride, dibutyltin dilaurate, titanium chloride, titanium tetraisopropoxide, aluminum chloride, trichloride Known compounds such as boron, boron trifluoride, and zinc chloride can be used, and tin chloride is particularly preferable, but is not limited thereto.

Further, those having an isocyanate group are also preferable. In particular, terminal isocyanate alkyl trialkoxysilanes represented by γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, etc. are easily available and are good. But,
It is not limited to this.

It is also preferable to add a resin or other silane coupling agent for the purpose of improving the mechanical strength of the protective layer, preventing cracks, and improving flexibility, but the present invention is not limited thereto.

As a method for forming the protective layer, a usual wet coating method can be used similarly to the gas barrier coating layer. For example, dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, gravure offset, and the like can be used. The coating is applied to one or both surfaces of the substrate by using these coating methods. The drying method for drying is a known and commonly used drying method such as hot air drying, hot roll drying, and infrared irradiation, and is not particularly limited.

When the coating layer is formed on one side of the substrate, the thickness of the coating layer after drying is about 0.01 to 100.
It is preferable to coat so as to have a thickness of μm, and more desirably 0.01 to 50 μm. If it is thinner than this, a coating film is hardly formed, and even if formed, it is unstable. If it is too thick, it is uneconomical.

Next, the base material will be described. The plastic material mentioned here is, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN)
Polyester films such as polyethylene and polypropylene, polystyrene films, polystyrene films, polyamide films such as 6-nylon, polycarbonate films, engineering plastic films such as polyimide films, and the like were used, and these materials were formed by co-extrusion. Also included are composite multilayer films. Since the gas barrier composite coating of the present invention can be dried at a low temperature, it can be applied regardless of stretching or unstretching, but stable coating properties, film strength, dimensional stability, printability, price, disposal In consideration of the properties, transparency, hygiene, etc., a biaxially stretched single-layer film or a co-extruded composite multilayer film containing polypropylene, polyamide, or polyester as a main material is more preferable.

Further, the components of the substrate include printability,
From post-processing suitability, filling and packaging suitability, suitability as a packaging material such as suitability for contents, suitability for film formation, etc., various known additives and stabilizers such as antistatic agents, plasticizers,
Lubricants, antioxidants and the like may be added.

The term “surface modification treatment” as used herein refers to the purpose of enhancing the gas barrier function by facilitating the formation of a gas barrier coating, and to perform corona discharge treatment, low-temperature plasma treatment on one or both surfaces of the substrate surface, Improve the polarity of the surface by flame treatment, etc., wet-coat polyethyleneimine or its derivatives, silane coupling agents and organic titanates, polyacrylic, polyester, polyurethane, epoxy, isocyanate, polyamide resins, polyolefins It is to provide an anchor coat layer containing a system emulsion, a surfactant, or the like, or to provide a ceramic vapor deposition layer such as silicon oxide or aluminum oxide. In addition, gas due to the synergistic effect with the ceramic deposition layer It is intended to improve the barrier function.

The thickness of the base material is not particularly limited, but is practically in the range of 3 to 200 μm in consideration of suitability as a packaging material and the case of laminating another resin layer.
It is more preferable that the thickness be in the range of 3 to 30 μm depending on the price and the application.

Further, a practical laminated structure as a packaging material can be provided on the gas barrier coating surface or on the opposite surface. For example, it is a printing layer or a heat sealing layer such as a thermoplastic resin.

The printed layer is used for the purpose of merchantability, cosmetics, display display effect, etc. of the contents to be packaged, and is made of urethane, acrylic, nitrocellulose, polyamide,
A layer composed of a printing ink in which additives such as a pigment, a vehicle, a plasticizer, a drying agent, and a stabilizer are added to an ink binder resin such as a polyvinyl chloride-based resin, and characters, pictures, and the like are formed. ing. As a forming method, for example, a well-known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a well-known coating method such as a roll coat, a knife edge coat, or a gravure coat can be used. The thickness is appropriately selected in the range of 0.1 to 2.0 μm.

When a multi-color gravure printing machine or the like is used for laminating the printing layers, the gas barrier coating layer may be provided first, and then the printing layers may be provided in-line using the same printing machine. .

The heat seal layer is used for an adhesive portion when forming a bag-like package, for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer. Resins such as ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer and metal cross-linked products thereof are used. The thickness is determined according to the purpose, but is generally 15 to 200 μm.
Is appropriately selected within the range.

As a method for forming the heat seal layer, a dry laminating method in which a film-like material made of the above-mentioned resin is bonded using a two-component curable urethane-based adhesive, and a non-solvent type in which a film-shaped resin-based adhesive is bonded using a solventless adhesive are used. Any of a dry lamination method, an extrusion lamination method in which the above-described resin is heated and melted, and extruded in a curtain shape, and the like can be formed by a known lamination method.

[0042]

EXAMPLES The gas barrier film of the present invention will be further described with reference to specific examples. However, this example does not limit the present invention.

<Preparation of Gas Barrier Coating Solution> Composite solution A: Lithium silicate aqueous solution (Li ₂ O.nS)
iO ₂ , n = about 5 molar ratio)
An aqueous solution in which a silane coupling agent N- (2-aminoethyl) 3-aminopropyltrimethoxysilane is dissolved as a nitrogen compound, polyvinyl alcohol (Kuraray ^{TM ™} “PVA117”, a saponification degree of about 9) as a water-soluble polymer
9mol%, degree of polymerization of about 1700)
Complex liquid A was obtained by adding iO ₂ (derived from lithium silicate) / hydrolyzate of silane coupling agent / polyvinyl alcohol so as to be 90/10/10 in terms of solid content weight and stirring.

Composite liquid B: lithium silicate aqueous solution (L
_{i 2 O · nSiO 2, n} = about the aqueous solution solids Preparation of 5 molar ratio), nitrogen compound as the silane coupling agent 3
Aqueous solution of aminopropyltrimethoxysilane, polyvinyl alcohol (water-soluble polymer)
Kuraray ^TM "PVA117", saponification degree about 99mol
%, The degree of polymerization of about 1700)
₂ (derived from lithium silicate) / hydrolyzate of silane coupling agent / polyvinyl alcohol so as to be 90/10/10 in terms of solid content weight, and stirred.
I got

Composite liquid C: lithium silicate aqueous solution (L
_{i 2 O · nSiO 2, n} = the aqueous solution solids prepared from about 5 mole ratio), a silane coupling as nitrogen compound agent N
An aqueous solution in which-(2-aminoethyl) 3-aminopropyltrimethoxysilane is dissolved, and a silanol group-modified polyvinyl alcohol as a water-soluble polymer (Kuraray Co., Ltd.)
An aqueous solution in which ^TM “R-1130”, a degree of saponification of about 99 mol%) is dissolved becomes 90/10/10 in terms of solid content weight of SiO ₂ (derived from lithium silicate) / silane coupling agent hydrolyzate / polyvinyl alcohol. And the mixture was stirred to obtain a composite liquid C.

Complex liquid D: lithium silicate aqueous solution (L
_{i 2 O · nSiO 2, n} = the aqueous solution solids prepared from about 5 mole ratio), a silane coupling as nitrogen compound agent N
- (2-aminoethyl) 3-aminopropyltrimethoxysilane aqueous solution prepared by dissolving cellulose (Tokyo Kasei Kogyo Co., Ltd. hydroxyethyl cellulose, 4500~6500cps2% water) as a water-soluble polymer SiO ₂ an aqueous solution prepared by dissolving ( (From lithium silicate) / silane coupling agent hydrolyzate / cellulose in a solid content of 90/10/10 in terms of weight and stirred.
A composite liquid D was obtained.

Single solution E: Lithium silicate aqueous solution (L
An aqueous solution having a solid content of i ₂ O · nSiO ₂ (n = about 5 mole ratio) was prepared to obtain a single solution E.

Mixtures F and G: A mixture of tetraethoxysilane and 2- (3,4-epoxycyclohexyl) trimethoxysilane in a 5/1 (molar ratio) mixture f, 3/1 (mo)
l ratio) A mixed solution g was prepared. Subsequently, a mixed solution of 0.1N hydrochloric acid / methanol (1/1 weight ratio) was added to these with water / Si = 1.
6/1 (mol ratio) and stirred for 1 hour,
Mixtures F and G were obtained, respectively.

Mixed solution H: The concentration of γ-isocyanatopropyltrimethoxysilane was adjusted to obtain a mixed solution H of an ethyl acetate solution.

Mixture I: tetraethoxysilane and 2-
A 5/1 (molar ratio) mixed solution of (3,4-epoxycyclohexyl) trimethoxysilane was prepared, and then a 0.1N hydrochloric acid / methanol (1/1 weight ratio) mixed solution was added thereto with water / Si = 16. / 1 (mol ratio)
After stirring for an hour and adjusting the concentration with ethyl acetate, H was added to obtain a mixed solution I.

Example 1 A composite liquid A was applied as a gas barrier coating to one side of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm provided with a urethane undercoat layer by a gravure coating method and dried in an oven at 80 ° C. To form a coating film having a thickness of about 1 μm, and further apply a mixed solution F by a gravure coating method in the same procedure.
By drying in an oven at ℃, a coating having a thickness of about 1 μm was formed to obtain a gas barrier film.

<Example 2> A gas barrier film was obtained in the same manner as in Example 1 except that the composite solution B was used in forming the barrier film.

Example 3 A gas barrier film was obtained in the same manner as in Example 1 except that the composite solution C was used in forming the barrier film.

<Example 4> A gas barrier film was obtained in the same manner as in Example 1 except that the composite liquid D was used in forming the barrier film.

<Example 5> A gas barrier film was obtained in the same manner as in Example 1 except that the mixed solution G was used in forming the protective film.

Example 6 A composite liquid A was applied as a gas barrier coating to one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm provided with a urethane undercoat layer by a gravure coating method and dried in an oven at 80 ° C. To form a coating film having a thickness of about 1 μm.
By drying in an oven at ℃, a coating having a thickness of about 1 μm was formed to obtain a gas barrier film.

Example 7 A gas barrier film was obtained in the same manner as in Example 6, except that the composite solution B was used in forming the barrier film.

Example 8 A gas barrier film was obtained in the same manner as in Example 6, except that the composite solution C was used in forming the barrier film.

Example 9 A gas barrier film was obtained in the same manner as in Example 6, except that the composite solution D was used in forming the barrier film.

Comparative Example 1 A gas barrier film was obtained in the same manner as in Example 1 except that no protective film was formed.

Comparative Example 2 A gas barrier film was obtained in the same manner as in Example 2 except that no protective film was formed.

Comparative Example 3 A gas barrier film was obtained in the same manner as in Example 3 except that no protective film was formed.

Comparative Example 4 A gas barrier film was obtained in the same manner as in Example 4 except that no protective film was formed.

<Comparative Example 5> A gas barrier film was obtained in the same manner as in Example 1 except that the simple solution E was used for forming the barrier film and the protective film was not formed.

Comparative Example 6 A gas barrier film was obtained in the same manner as in Example 6, except that no protective film was formed.

Comparative Example 7 A gas barrier film was obtained in the same manner as in Example 7, except that the protective film was not formed.

Comparative Example 8 A gas barrier film was obtained in the same manner as in Example 8 except that no protective film was formed.

Comparative Example 9 A gas barrier film was obtained in the same manner as in Example 9 except that no protective film was formed.

<Comparative Example 10> A single solution E was used for forming a barrier film.
And a gas barrier film was obtained in the same manner as in Example 6, except that no protective film was formed.

<Evaluation 1> For the ten types of gas barrier films of Examples 1 to 5 and Comparative Examples 1 to 5 described above,
MOCON- manufactured by Modern Control Co., Ltd.
It was measured using OXTRAN 10 / 50A. The measurement conditions were 30 ° C. and 90 RH, and the results are shown in Table 1. In addition, the oxygen permeability after exposure at 40 ° C. and 90% RH for 2 weeks was measured. Table 1 also shows the results.

[0071]

[Table 1]

<Evaluation 2> The oxygen permeability of each of the ten types of gas barrier films of Examples 6 to 10 and Comparative Examples 6 to 10 was measured using MOCO manufactured by Modern Control.
It measured using N-OXTRAN10 / 50A. The measurement conditions were 30 ° C. and 90 RH, and the results are shown in Table 1. In addition, the oxygen permeability after exposure at 40 ° C. and 90% RH for 2 weeks was measured. Table 2 also shows the results. At the same time, a cellophane tape was stuck on each of the film formation surfaces, and when the cellophane tape was peeled off, it was visually observed whether or not the film was peeled. Table 2 also shows the results.

[0073]

[Table 2]

<Evaluation Results> From the results of Evaluation 1 and Evaluation 2, on the barrier layer having lithium polysilicate, an amino group-containing silane coupling agent and polyvinyl alcohol as components, tetraethoxysilane and / or 2- (3,
It has been found that a gas barrier film provided with a protective layer having a hydrolyzate of 4-epoxycyclohexyl) trimethoxysilane as a component has high gas barrier properties even when exposed under high humidity conditions. It was also found that the cellophage tape adhesion was good.

[0075]

According to the present invention, a gas barrier film having low oxygen permeability and excellent storage suitability can be obtained at a lower temperature condition than before.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a gas barrier film of the present invention.

[Explanation of symbols]

 100 gas barrier film 110 substrate 120 gas barrier film 130 protective layer

Continuing from the front page (72) Inventor Kenji Hayashi 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Risato Kitahara 1-15-1 Taito, Taito-ku, Tokyo Letterpress stamp (72) Inventor: Tomonori Komori 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. F-term (reference) BA10A BA10C EH46 EJ38 EJ67B EJ67C EJ91 GB15 JB09B JD02B JD03 JK06 JL00 JL09 JL11 JN01

Claims (11)

[Claims] (1) M ₂ O · nSiO is provided on at least one surface of a substrate.
₂ (M is lithium or a plurality of alkali metals containing lithium, n is a molar ratio in the range of 1 to 20) Gas barrier coating mainly composed of an alkali metal polysilicate, a nitrogen compound and a water-soluble polymer , And a protective layer mainly comprising a metal alkoxide and / or a silane coupling agent or a hydrolyzate thereof is provided thereon. 2. The gas barrier film according to claim 1, wherein said nitrogen compound is an amino group-containing silane coupling agent. 3. The gas barrier film according to claim 1, wherein the water-soluble polymer is a saccharide, polyvinyl alcohol, polyethyleneimine or a derivative thereof. 4. The composition of claim ₂ , wherein said SiO ₂ component in said gas barrier coating is
The weight ratio of (nitrogen compound + water-soluble polymer) is 50/50
The gas barrier film according to any one of claims 1 to 3, wherein the gas barrier film is in a range of from 99.99 / 0.01. 5. The gas barrier film according to claim 1, wherein the metal of the metal alkoxide of the protective layer contains at least one of silicon, titanium, aluminum, zirconium and niobium. 6. The gas barrier film according to claim 1, wherein the metal alkoxide of the protective layer contains at least one of tetraethoxysilane, tetramethoxysilane and a polymer thereof. 7. The gas barrier film according to claim 1, wherein the silane coupling agent of the protective layer has an epoxy group. 8. The gas barrier film according to claim 1, wherein a Lewis acid is added to a mixture containing a metal alkoxide or a hydrolyzate thereof in forming the protective layer. 9. The gas barrier film according to claim 1, wherein the Lewis acid contains at least one compound of tin, titanium, aluminum, boron and zinc. 10. The method according to claim 1, wherein the silane coupling agent in the protective layer has an isocyanate group.
7. The gas barrier film for lamination according to any one of items 1 to 6. 11. The method according to claim 1, wherein the base material is a plastic film made of a plastic material or a plastic material subjected to a surface modification treatment.
0. A gas barrier film described in 0.