JP2007098654A - Gas barrier film and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier film having good barrier properties against oxygen or steam. <P>SOLUTION: The gas barrier film comprises: a base material 2; the gas barrier layer 3 formed at least on one side of the base material 2 and comprising a vapor deposition film; and a sol-gel coating layer 4 formed on the gas barrier layer 3 and comprising a film containing a hydrolysate of an organometal compound or an alkali metal polysilicate represented by the formula M<SB>2</SB>O-nSiO<SB>2</SB>(wherein M is lithium or a plurality of alkali metals containing lithium and n is a molar ratio of 1-20) and sugars. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas barrier film mainly used as a packaging material such as a packaging material such as food or medicine or an electronic device, and a method for producing the same.

  The gas barrier film is mainly used as a packaging material for food and pharmaceuticals to prevent the influence of oxygen and water vapor, which cause the quality of the contents to change, and is formed on liquid crystal display panels and EL display panels. In order to avoid degradation of the performance of the element being exposed to oxygen or water vapor, it is used as a packaging material for electronic devices and the like. In recent years, gas barrier films are sometimes used for reasons such as imparting flexibility and impact resistance to portions where glass has been used conventionally.

  As such a gas barrier film, a base material made of a polyvinylidene chloride resin, a copolymer resin of vinylidene chloride and another polymer, or these vinylidene chloride resins are coated on a polypropylene resin, a polyester resin, or a polyamide resin. Those with gas barrier properties are widely used especially as packaging materials, but since chlorine-based gas is generated by incineration, it is currently a problem in terms of environmental protection, and the gas barrier properties are not always sufficient. In addition, there is a problem that it cannot be used for contents that require high barrier properties.

  Polyvinyl alcohol (PVA) and ethylene vinyl alcohol copolymer (EVOH) are also used as gas barrier films, but these show relatively good gas barrier properties under absolutely dry conditions, but the water vapor barrier properties are not sufficient. Moreover, since the oxygen barrier property deteriorates under humidity conditions, it cannot be said to be a sufficient gas barrier material under realistic conditions.

  Therefore, a method for depositing an inorganic oxide such as silicon oxide by a vacuum deposition method (for example, see Patent Document 1) has been proposed as a gas barrier film realizing high barrier properties. Such a gas barrier film has a significantly improved gas barrier property as compared with a gas barrier film made of a resin as described above. However, the deposited film formed by such a vacuum deposition method often has defects such as pinholes and cracks on the surface, and gases such as oxygen and water vapor escape from the defective parts such as pinholes and cracks. As a result, the gas barrier property of the gas barrier film is lowered.

JP-A-8-176326

  This invention is made | formed in view of the said problem, and it aims at providing the gas barrier film with favorable barrier property with respect to oxygen and water vapor | steam.

In order to achieve the above object, the present invention provides a base material, a gas barrier layer formed on at least one surface of the base material and made of a vapor deposition film, and formed on the gas barrier layer to hydrolyze an organometallic compound. Or an alkali metal polysilicate represented by M ₂ O.nSiO ₂ (M is lithium or a plurality of alkali metals including lithium, and n is within a range of 1 to 20 in a molar ratio), and a film containing a saccharide. A gas barrier film comprising a sol-gel coating layer is provided.

  According to the present invention, since the sol-gel coating layer is formed on the gas barrier layer, even if a defect such as a pinhole or a crack occurs on the surface of the gas barrier layer, the pinhole or crack or the like Can be filled with the sol-gel coat layer, and the gas barrier property of the gas barrier layer can be prevented from being lowered. Further, by incorporating saccharides into the sol-gel coat layer, it becomes possible to improve the adhesion with the gas barrier layer, and it is possible to impart good film formability and flexibility to the sol-gel coat layer. It is possible to prevent cracks and the like from occurring during curing shrinkage due to drying during layer formation.

  In the said invention, it is preferable that the weight average molecular weights of the said saccharide | sugar are in the range of 1-5 million. Thereby, the viscosity of the coating solution for forming a sol-gel coat layer used when forming the sol-gel coat layer can be made suitable for coating. Therefore, the sol-gel coat layer can be formed into a uniform film without uneven coating, the adhesion between the sol-gel coat layer and the gas barrier layer can be improved, and a gas barrier film with good gas barrier properties can be obtained.

  Moreover, in this invention, it is preferable that the film thickness of the said sol-gel coat layer exists in the range of 0.01 micrometer-50 micrometers. When the film thickness of the sol-gel coat layer is within the above range, it is possible to effectively prevent cracks and the like from being generated during the formation of the sol-gel coat layer, and to maintain good gas barrier properties. Because. In addition, when the film thickness of the sol-gel coat layer is within the above range, the quick-drying property of the sol-gel coat layer can be improved during film formation of the sol-gel coat layer, which is advantageous in the manufacturing process.

  Furthermore, in the present invention, an anchor layer may be formed between the base material and the gas barrier layer. This makes it possible to improve the adhesion between the base material and the gas barrier layer. For example, even when the gas barrier film of the present invention is used for a flexible packaging material, This is because problems such as peeling of the gas barrier layer do not occur, and good gas barrier properties can be maintained.

  In the present invention, an overcoat layer may be formed on the sol-gel coat layer. This is because the formation of an overcoat layer on the sol-gel coat layer can prevent the occurrence of heat, rubbing, and damage caused by tension during lamination and printing, and can improve moisture resistance.

The present invention also includes a gas barrier layer forming step of forming a gas barrier layer on a substrate by vapor deposition, and a hydrolyzate of an organometallic compound or M ₂ O.nSiO ₂ (M is lithium or Apply a coating solution for forming a sol-gel coating layer containing a plurality of alkali metals including lithium, n is within a range of 1 to 20 in terms of a molar ratio, and a saccharide, and is cured by a sol-gel reaction. A sol-gel coating layer forming step of forming a sol-gel coating layer, wherein the viscosity of the sol-gel coating layer forming coating liquid is in the range of 1 Pa · s to 1000 Pa · s at 25 ° C. A method for producing a gas barrier film is provided.

  According to the present invention, since the viscosity of the sol-gel coat layer forming coating solution is within the above range, the coating property of the sol-gel coat layer forming coating solution can be improved. . Therefore, a uniform film without uneven coating can be formed, and a gas barrier film having a good barrier property against oxygen and water vapor can be obtained.

  According to the present invention, even when a defect such as a pinhole or a crack occurs on the surface of the gas barrier layer, it becomes possible to compensate the defect by filling the pinhole or crack with the sol-gel coat layer. In addition, since the sol-gel coat layer contains saccharides, adhesion to the gas barrier layer is improved, good film formability and flexibility are imparted, and cracks and the like are prevented from occurring on the surface of the sol-gel coat layer. It becomes possible. Therefore, by providing the sol-gel coat layer on the gas barrier layer, the gas barrier property of the gas barrier film can be improved.

  Hereinafter, the gas barrier film of the present invention and the method for producing the gas barrier film will be described in detail.

A. Gas barrier film First, the gas barrier film of this invention is demonstrated. The gas barrier film of the present invention is formed on at least one surface of the base material, the gas barrier layer made of a vapor deposition film, and formed on the gas barrier layer. The hydrolyzate of organometallic compound or M ₂ O A sol-gel coat layer comprising an alkali metal polysilicate represented by nSiO ₂ (M is lithium or a plurality of alkali metals containing lithium, and n is in a range of 1 to 20 in a molar ratio), and a saccharide-containing film It is what you have.

  FIG. 1 is a schematic cross-sectional view showing an example of the gas barrier film of the present invention. As shown in FIG. 1, the gas barrier film 1 of the present invention includes a base material 2, a gas barrier layer 3 formed on at least one surface of the base material 2, and a sol-gel coat layer 4 formed on the gas barrier layer 3. It is what has.

  In the present invention, the gas barrier layer is composed of a vapor deposition film. In general, however, such a vapor deposition film is liable to cause defects such as pinholes and cracks on the surface in the formation process thereof, and oxygen or water vapor can be generated from the defects. In some cases, the gas barrier property is lowered and the gas barrier property is lowered. Therefore, in the present invention, by providing a sol-gel coat layer formed by a sol-gel reaction on the gas barrier layer made of such a deposited film, the gas barrier property is prevented from being lowered. According to the present invention, even when defects such as pinholes and cracks occur on the surface of the gas barrier layer, the pinholes and cracks are filled with the sol-gel coat layer by providing the sol-gel coat layer on the gas barrier layer. And it becomes possible to make up for defects. Therefore, a gas barrier film having good gas barrier properties can be obtained.

Moreover, in this invention, it becomes possible to improve adhesiveness with a gas barrier layer by containing saccharides in a sol-gel coat layer. Furthermore, by including saccharides in the sol-gel coat layer, it is possible to impart good film formability and flexibility, and cracks and the like occur during shrinkage due to drying during film formation of the sol-gel coat layer. It becomes possible to prevent. For example, when lithium polysilicate is used as the alkali metal polysilicate, conventionally, when lithium polysilicate alone is to be formed on a substrate, it may not be formed depending on the molar ratio of Li ₂ O and SiO _2. In some cases, cracks may occur and the gas barrier property may be lowered. However, in the present invention, by including a saccharide, film forming property and flexibility can be imparted, and thus the gas barrier property can be enhanced. It is. Thereby, high gas barrier property can be provided to a gas barrier film.

Further, the sol-gel coat layer in the present invention is represented by a hydrolyzate of an organometallic compound or M ₂ O.nSiO ₂ (M is lithium or a plurality of alkali metals containing lithium, and n is a molar ratio in the range of 1 to 20). Since it is a layer containing any one of the alkali metal polysilicates to be formed, the sol-gel coat layer forming coating liquid used for forming the sol-gel coat layer can have a high affinity for the gas barrier layer. . Therefore, it is possible to improve the coating property of the sol-gel coating layer forming coating liquid and the sol-gel coating layer forming property when forming the sol-gel coating layer. In addition, the adhesion between the sol-gel coat layer and the gas barrier layer can be improved.
Hereinafter, each structure of such a gas barrier film is demonstrated.

1. Sol-gel coating layer The sol-gel coating layer used in the present invention is formed on a gas barrier layer described later, and is a hydrolyzate of an organometallic compound or M ₂ O.nSiO ₂ (M is lithium or a plurality of alkali metals including lithium, n Is made of a film containing an alkali metal polysilicate represented by a molar ratio of 1 to 20) and a saccharide.

  Examples of the saccharide used in the present invention include amylouronic acid, seurouronic acid, glucose, galactose, fructose, mannose, fucose, rhamnose, glucuronic acid, glucosamine, sorbitol, arabinose, ribose, deoxyribose and other monosaccharides, maltose, lactose, Examples thereof include oligosaccharides such as sucrose, trehalose, maltotriose, meletose and stachyose, and polysaccharides such as starches, celluloses, pullulans, dextrins, chitins and chitosans. Of these, amylouronic acid and cellouronic acid are preferably used. This is because amylouronic acid and ceurouronic acid have a relatively high weight average molecular weight and are excellent in film forming properties. Moreover, it is because the sol-gel coat layer using amylouronic acid or seurouronic acid has high adhesion to a base material such as polyester such as polyethylene terephthalate.

  Examples of the saccharide used in the present invention include water-soluble polysaccharides containing uronic acid residues. Examples of the water-soluble polysaccharide containing a uronic acid residue include a polyuronic acid composed of one or more uronic acid residues and a uronic acid residue such as a mucopolysaccharide and other sugar residues. Mention may be made of polysaccharides. The carboxylic acid of the uronic acid residue may be a carboxylic acid or a carboxylate.

Examples of such a water-soluble polysaccharide containing a uronic acid residue include pectinic acid, alginic acid, hyaluronic acid, or metal salts thereof.
Examples of the water-soluble polysaccharide containing a uronic acid residue include an α- or β-glucoside-linked glucuronic acid or a polysaccharide containing glucuronic acid salt. In the case of a polysaccharide composed of glucuronic acid and glucose, the glucuronic acid content in the polysaccharide is preferably 60% or more, and more preferably 90% or more.

Furthermore, as the water-soluble polysaccharide containing the uronic acid residue, for example, natural polysaccharides such as starch and cellulose are oxidized, and the 6-position hydroxyl group of the pyranose ring (glucose) is selectively carboxyl group (or its). Mention may be made of polysaccharides converted into (metal salts). Examples of such polysaccharides include polysaccharides having a uronic acid residue content of 60% or more in the total sugar residues of polysaccharides, and amylouronic acid obtained by converting almost all 6-position hydroxyl groups to carboxyl groups. , Polyglucuronic acid such as celouronic acid, or metal salts thereof. Amilouronic acid, seurouronic acid, or a metal salt thereof preferably has a pullulan conversion degree measured by GPC in the range of DPw = 25 or more, and more preferably in the range of DPw = 100 or more. This is because the crystallinity can be increased and the water resistance and moisture resistance can be improved.
Further, as the polysaccharide, fine cellulose containing glucuronic acid residues and glucose residues obtained by oxidizing cellulose and selectively converting the carbon 6 position of the glucopyranose ring to a carboxyl group may be used. In this case, the amount of the carboxyl group is preferably in the range of 1% to 60%, more preferably in the range of 1% to 30% with respect to the total number of moles of monosaccharides constituting the cellulose. Fine cellulose in this range is insoluble in water, but is very familiar and dispersible. Furthermore, high gas barrier properties can be imparted to the gas barrier film by introducing carboxyl groups having higher polarity and higher hydrogen bonding ability than the hydroxyl groups originally present in cellulose.

The weight average molecular weight of such saccharides varies depending on the type of saccharide to be used, but specifically it is preferably in the range of 1 to 5 million, particularly in the range of 500 to 1 million, especially 500 It is preferable to be within a range of ˜500,000. When the weight average molecular weight of the saccharide exceeds the above range, the viscosity of the sol-gel coat layer forming coating solution becomes too high, and thus when the sol-gel coat layer is formed, coating unevenness occurs and good gas barrier properties are obtained. This is because there is a possibility that it will be difficult to be made. Moreover, it is because favorable film-forming property is acquired because the weight average molecular weight of saccharides is the said range.
The weight average molecular weight can be measured by a gel permeation chromatography (GPC) method, and is a high-speed GPC device manufactured by Tosoh Corporation. The column is Tosoh Corporation TSK-gelPW (trade name), and the organic solvent is A value measured using THF at a flow rate of 0.5 cc / min can be used.

  Moreover, as content of such saccharides, in a sol-gel coat layer, it exists in the range of 0.01 mass%-50 mass%, especially in the range of 0.05 mass%-25 mass%, especially 0.1 mass%. It is preferable to be within the range of -10% by mass. When the saccharide content exceeds the above range, when forming the sol-gel coat layer, it is difficult to obtain a good coating property of the sol-gel coat layer forming coating solution, and the film forming property of the sol-gel coat layer becomes insufficient. This is because it may be difficult to form a uniform film. Moreover, it is because it becomes difficult to obtain favorable adhesiveness when the saccharide content is less than the above range.

The sol-gel coat layer is represented by a hydrolyzate of an organometallic compound, or M ₂ O · nSiO ₂ (M is lithium or a plurality of alkali metals including lithium, and n is in a molar ratio of 1 to 20). One of the alkali metal polysilicates to be produced.

In the present invention, the “hydrolyzate of an organometallic compound” refers to an organometallic compound or a hydrolyzate of an organometallic compound, and includes an organometallic compound.
The hydrolyzate of the organometallic compound used in the present invention is not particularly limited. For example, the general formula A _m M (OR) _nm (wherein A is carbon having 1 to 10 carbons) Composed of one or more main chains, M is a metal element, R is an alkyl group, n is an oxidation number of the metal element, m is a substitution number (0 ≦ m <n), Or it is preferable to consist of a polymer of the said organometallic compound. The substituent of the organometallic compound represented by the above general formula may have a vinyl group, an epoxy group, an alkyl group, or an amino group. By adding one or more of these organometallic compounds, Functions, particularly water resistance and moisture resistance can be imparted.

  The metal element M represented by the above general formula is preferably silicon (Si), aluminum (Al), or titanium (Ti).

In addition, as an alkali metal polysilicate represented by M ₂ O · nSiO ₂ (M is lithium or a plurality of alkali metals containing lithium, n is in a range of 1 to 20 in molar ratio) used in the present invention, Li _The lithium silicate represented by ₂ O.nSiO ₂ (n is a molar ratio) is an essential component. This is because when a film containing an alkali metal polysilicate composed of one or more alkali metals not containing lithium cannot achieve a stable and high gas barrier property under high temperature and high humidity when laminated with a gas barrier layer. Because there is.
In the present invention, since the gas barrier property is improved by laminating the gas barrier layer and the sol-gel coat layer, the sol-gel coat layer itself may not have the gas barrier property. Therefore, the alkali metal polysilicate may contain an alkali metal silicate other than lithium, for example, sodium silicate or potassium silicate. Sodium silicate is inexpensive and advantageous in terms of cost, and potassium silicate has good water resistance.
As the alkali metal polysilicate solution, an aqueous alkali silicate solution generally known as water glass (commonly called sodium silicate aqueous solution) using water as a solvent is used.

  The blending ratio of the hydrolyzate or alkali metal polysilicate of the organometallic compound and the saccharide is appropriately adjusted in consideration of film strength, water resistance and the like.

  In the present invention, the sol-gel coat layer may contain additives such as inorganic layered compounds and nitrogen compounds.

An inorganic layered compound refers to a crystalline inorganic compound having a layered structure. Since the inorganic layered compound can block the permeation of gases such as oxygen and water vapor, if the sol-gel coat layer contains an inorganic layered compound, the gas will pass through the sol-gel coat layer to avoid the inorganic layered compound. , Gas barrier properties can be improved. Examples of the inorganic layered compound include kaolinite group, smectite group, mica group and other clay minerals. In general, examples of the smectite group inorganic layered compound include montmorillonite, hectorite, saponite, and the like. Among these, in the sol-gel coat layer forming coating solution used when forming the sol-gel coat layer. Montmorillonite is preferable from the standpoints of stability and coating properties.
When the inorganic stratified compound is contained in the sol-gel coat layer, the weight ratio of the inorganic stratified compound to the saccharide can be in the range of 1:99 to 99: 1.

  Moreover, when the sol-gel coat layer contains a nitrogen compound, densification of the sol-gel coat layer can be promoted. As the nitrogen compound, amines containing an amino group-containing silane coupling agent are preferably used in consideration of compatibility with the hydrolyzate of an organometallic compound and alkali metal polysilicate and flexibility. This is because a high barrier property against water vapor can be realized by containing an amine containing an amino group-containing silane coupling agent in the sol-gel coat layer.

  Further, when the alkali metal polysilicate is used, the sol-gel coat layer may contain an organosilicon compound as an additive. This is because the organosilicon compound can improve film formability and adhesion, and can prevent occurrence of cracks in the sol-gel coat layer. As the organosilicon compound, those having a lower alkoxyl group having 1 to 3 carbon atoms such as methoxy group or ethoxy group, alkoxysilane, dialkoxysilane, and trialkoxysilane terminal hydrolyzable are particularly preferably used. This is because such an organosilicon compound has good compatibility and dispersibility with the alkali metal polysilicate.

  Here, the film thickness of such a sol-gel coating layer is preferably in the range of 0.01 μm to 50 μm, more preferably in the range of 0.1 μm to 10 μm, and particularly in the range of 0.5 μm to 5 μm. Is preferred. As a result, it is possible to prevent cracks and the like from occurring during curing shrinkage due to drying during film formation of the sol-gel coat layer, and to suppress a decrease in gas barrier properties. Moreover, when the film thickness of the sol-gel coat layer is within the above range, the quick-drying property of the sol-gel coat layer can be enhanced, which is advantageous in the production process. Furthermore, if the film thickness of the gas barrier layer is within the above range, it is sufficiently possible to compensate for defects by filling pinholes, cracks, and the like of the gas barrier layer.

  The method for forming the sol-gel coat layer will be described in detail in the section “B. Method for producing gas barrier film” described later, and will not be described here.

2. Gas barrier layer The gas barrier layer used in the present invention is not particularly limited as long as it is a vapor deposition film formed on a base material in order to impart gas barrier properties, and even if it is a transparent film, it is an opaque film. Also good.

Examples of the material when the deposited film is a transparent film include silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, aluminum oxide, calcium oxide, magnesium oxide, zirconium oxide, titanium oxide, and titanium nitride. it can.
In addition to silicon and oxygen, which are the main constituent elements, the deposited film made of silicon oxide is made of metals such as aluminum, magnesium, calcium, potassium, sodium, titanium, zirconium, yttrium, carbon, boron, nitrogen, fluorine, etc. The nonmetallic element may be included.
On the other hand, examples of the material for forming the opaque film include aluminum, titanium, and silicon.

  In the present invention, silicon oxide is preferably used among the above materials. This is because the deposited film formed using silicon oxide has good adhesion to the sol-gel coat layer, the base material, and an anchor layer described later.

  The gas barrier layer may be a single layer, or a plurality of gas barrier layers may be laminated in order to improve barrier properties. Moreover, as a combination in the case of stacking, the same kind or different kinds may be used.

  Further, the gas barrier layer is formed on at least one surface of the base material described later, and may be formed on one surface of the base material, or formed on both surfaces of the base material. It may be.

  The thickness of such a gas barrier layer is not particularly limited as long as it has a barrier property against water vapor and oxygen, and is appropriately selected depending on the above-described materials. Usually, it is in the range of 5 nm to 5000 nm, preferably in the range of 50 nm to 1000 nm, particularly preferably in the range of 100 nm to 500 nm. Further, when aluminum oxide or silicon oxide is used, it is more preferably in the range of 10 nm to 300 nm. This is because if the thickness of the gas barrier layer is too thin, the barrier property is deteriorated. On the other hand, if the thickness of the gas barrier layer is too thick, cracks or the like may occur when the gas barrier layer is formed.

  The gas barrier layer can be formed by, for example, physical vapor deposition (PVD) such as sputtering, vapor deposition, or ion plating, or chemical vapor deposition (CVD). Among these, the chemical vapor deposition method is advantageous in that the influence of heat on the base material and the anchor layer described later can be relatively reduced at the time of forming the gas barrier layer, the production rate is high, and a uniform thin film is easily obtained. (CVD) is preferred.

3. Base material The base material used in the present invention is not particularly limited as long as it can hold the gas barrier layer composed of the above-described vapor-deposited film, and various commonly used sheets or films. The shaped substrate can be appropriately selected and used according to the application of the gas barrier film of the present invention.

  Examples of such a base material include biodegradable plastics such as paper, paperboard and polylactic acid, polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6). , Nylon-66, etc.), polyvinyl chloride, polyimide, polystyrene, polycarbonate, polyacrylonitrile, etc., or copolymers of these polymers. The plastic material may be either stretched or unstretched, and preferably has mechanical strength and dimensional stability.

  As this base material, those containing known additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant and a colorant can be used. Moreover, what improved the adhesiveness with the film formed in the surface by performing surface modification | reformation, such as corona treatment, ozone treatment, and plasma treatment, on the surface can also be used.

  The thickness of the substrate is not particularly limited, and is different depending on the use of the gas barrier film of the present invention, the layer configuration such as laminating other layers besides the gas barrier layer, etc. Practically, it is in the range of 3 to 200 μm, and more preferably 3 to 30 μm depending on the price and usage. Especially in packaging applications, the thickness is often about 12 μm.

4). Anchor Layer In the gas barrier film of the present invention, for example, as shown in FIG. 2, an anchor layer 6 may be formed between the substrate 2 and the gas barrier layer 3. By forming the anchor layer in this way, it becomes possible to improve the adhesion between the base material and the gas barrier layer. For example, the gas barrier film of the present invention is used for a flexible packaging material. Even in such a case, problems such as peeling of the gas barrier layer do not occur, and good gas barrier properties can be maintained.
As will be described later, when the gas barrier layer and the sol-gel coat layer are alternately and repeatedly laminated, the anchor is provided between the layer formed on the most substrate side of the laminated gas barrier layer and sol-gel coat layer and the substrate. A layer is formed.

  Materials used for the anchor layer include polyethyleneimine and derivatives thereof, silane coupling agents, organic titanates, polyacrylic resins, polyurethane resins, epoxy resins, polyurea resins, polyamide resins, polyolefin emulsions, interfaces. What contains an activator etc. can be used. In addition, an isocyanate compound or a mixture of an isocyanate compound and an acrylic resin can also be used.

  In the present invention, it is preferable that the material used for the anchor layer includes a urethane bond and a urea bond that are excellent in alkali resistance among the above-described materials.

  As a forming method when the anchor layer is provided, a normal coating method can be used. For example, dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing method, spray coating, gravure offset method and the like can be used. It apply | coats on a base material using these coating systems. The drying method is not particularly limited, such as hot air drying, hot roll drying, and infrared irradiation.

5. Overcoat layer In the gas barrier film of the present invention, an overcoat layer 7 may be formed on a sol-gel coat layer 4 as shown in FIG. By forming the overcoat layer in this way, heat, rubbing, and damage (cracks) caused by pulling during lamination and printing are prevented by the overcoat layer serving as a cushion, and moisture resistance is improved. It becomes possible.
As will be described later, when the gas barrier layer and the sol-gel coat layer are alternately and repeatedly laminated, an overcoat layer is formed on the outermost surface on which the gas barrier layer and the sol-gel coat layer are laminated.

  As the material of the overcoat layer, it can have a urethane bond and a urea bond excellent in alkali resistance, and specifically includes an isocyanate compound or a mixture of an isocyanate compound and an acrylic resin. Can do.

  As a formation method when the overcoat layer is formed using such a material, a formation method similar to the anchor layer described above can be used.

  As the thickness of the overcoat layer, if the thickness is 0.001 μm or less, adhesion and film-forming property cannot be obtained, and if it is 1 μm or more, it is not preferable. In general, the range of 0.1 μm to 1 μm is practical and preferable.

6). Other Layers The gas barrier film of the present invention may be provided with other layers in addition to the above-described layers. For example, a print layer, a heat seal layer, or the like may be provided.

  The printing layer is formed in order to practically use the gas barrier film of the present invention as a packaging bag, etc., and has been conventionally used inks such as urethane, acrylic, nitrocellulose, and rubber. Characters, pictures, and the like are formed by a layer composed of an ink obtained by adding various pigments, weatherable pigments, and additives such as plasticizers, drying agents, and stabilizers to the binder resin. As a forming method, for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as a roll coating or a gravure coating can be used. The thickness is appropriately selected within the range of 0.1 to 2.0 μm.

  Moreover, when using a multi-color printing machine when laminating a printing layer, after providing a sol-gel coat layer and / or an overcoat layer previously, you may provide a printing layer using the same printing machine as it is.

  Further, the heat seal layer is used for an adhesive part or the like when the gas barrier film of the present invention is used as a bag-like package, such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer. Resins such as coalescence, 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 in the range of 15 to 200 μm.

  As a method for forming the heat seal layer, a dry laminating method in which a film made of the above-described resin is bonded using a two-component curable urethane adhesive, a non-solvent dry laminating method in which a non-solvent adhesive is bonded, Any of the above-described extrusion laminating methods in which the above-described resin is heated and melted and extruded and pasted into a curtain shape can be formed by a known laminating method.

7). Gas barrier film In the present invention, by providing a sol-gel coat layer directly on the gas barrier layer, good gas barrier properties can be obtained, so if the gas barrier layer and the sol-gel coat layer are laminated directly from the substrate side, For example, the gas barrier layer and the sol-gel coat layer may be alternately and repeatedly laminated.

  For example, as shown in FIG. 3, a three-layer configuration in which a gas barrier layer 3, a sol-gel coat layer 4, and a gas barrier layer 3 are laminated in this order from the base material 2 side may be employed. With such a three-layer structure, pinholes and cracks of the gas barrier layer formed on the substrate are supplemented by the sol-gel coat layer formed thereon, and a gas barrier layer is further formed on the sol-gel coat layer. This is because the gas barrier property of the gas barrier film can be improved.

  For example, as illustrated in FIG. 4, a three-layer configuration in which a sol-gel coat layer 4, a gas barrier layer 3, and a sol-gel coat layer 4 are laminated in this order from the substrate 2 side may be employed. Since the sol-gel coat layer in the present invention contains saccharides, the layer structure as described above can improve the adhesion between the base material and the gas barrier layer, and obtain good gas barrier properties. be able to. Here, generally, when a vapor deposition film is formed directly on a substrate having high flexibility or the like, a crack or the like may easily occur in the vapor deposition film. In general, the sol-gel coat layer is often softer than the deposited film and harder than the substrate having high flexibility. For this reason, by laminating the sol-gel coat layer on the substrate as described above, the hardness of the surface on which the vapor deposition film is formed is increased, and the hardness suitable for forming the vapor deposition film can be obtained. Therefore, with the above-described configuration, it is possible to prevent cracks from being generated in the gas barrier layer when the gas barrier is formed on the sol-gel coat layer.

  Furthermore, for example, as shown in FIG. 5, a four-layer structure in which the gas barrier layer 3, the sol-gel coat layer 4, the gas barrier layer 3, and the sol-gel coat layer 4 are laminated in this order from the substrate 2 side may be used. There may be. This is because a further excellent barrier property can be obtained.

When the gas barrier layer and the sol-gel coat layer are alternately and repeatedly laminated as described above, the adhesion between the layers is good, so that the gas barrier layer is formed thick or stacked in order to improve the gas barrier property as in the past. Unlike the above, there is an advantage that peeling and cracking hardly occur. In the present invention, since the gas barrier property is improved by directly laminating the gas barrier layer and the sol-gel coat layer, it is not necessary to increase the thickness of each layer, and the gas barrier layer and the sol-gel coat layer are alternately and repeatedly laminated. And even if it is set as a multilayer structure, the thickness of the whole gas barrier film can be suppressed.
In the case where the gas barrier layer and the sol-gel coat layer are provided in an overlapping manner, the number of layers may be two or more. However, considering the total thickness of the gas barrier film, it is preferable that the number is about eight.

As the gas barrier property of the gas barrier film of the present invention, the oxygen permeability (OTR) is preferably 1 cc / m ² / day / atm or less, more preferably 0.5 cc / m ² / day / atm or less, particularly 0. It is preferably 1 cc / m ² / day / atm or less. The water vapor transmission rate (WVTR) is preferably 1 g / m ² / day or less, more preferably 0.5 g / m ² / day or less, and particularly preferably 0.1 g / m ² / day or less. .
The oxygen permeability is measured using an oxygen gas permeability measuring device (manufactured by Modern Control Co., Ltd., OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a humidity of 90% Rh. It is the value. The water vapor transmission rate was measured using a water vapor transmission rate measuring device (manufactured by Modern Control Co., Ltd., PERMATRAN-W 3/31: trade name) under the conditions of a measurement temperature of 37.8 ° C. and a humidity of 100% Rh. It is a measured value.

  The gas barrier film of the present invention hardly permeates oxygen and water vapor that cause changes in the quality of the contents, and therefore uses for which high gas barrier properties are required, for example, packaging materials such as foods and pharmaceuticals, and packaging materials such as electronic devices Can be preferably used. Moreover, from the point which has the high gas barrier property and impact resistance, it can be used as a base material for various displays, for example. It can also be used for solar cell cover films and the like.

B. Next, a method for producing the gas barrier film of the present invention will be described. The method for producing a gas barrier film of the present invention includes a gas barrier layer forming step of forming a gas barrier layer on a substrate by vapor deposition, and a hydrolyzate of an organometallic compound or M ₂ O.nSiO ₂ (on the gas barrier layer. M is a lithium or a plurality of alkali metals containing lithium, n is an alkali metal polysilicate represented by a molar ratio in the range of 1 to 20, and a sol-gel coating layer forming coating solution containing a saccharide, And a sol-gel coat layer forming step of forming a sol-gel coat layer by curing by a sol-gel reaction, wherein the viscosity of the sol-gel coat layer forming coating liquid is 1 Pa · s to 1000 Pa at 25 ° C. -It is characterized by being within the range of s.

  Generally, when the sol-gel coat layer forming coating solution is applied onto a substrate, if the viscosity of the sol-gel coat layer forming coating solution is too high, uneven coating tends to occur and a uniform film can be formed. It becomes difficult. Therefore, in the present invention, the viscosity of the sol-gel coating layer forming coating solution is set within the above range. Thereby, it becomes possible to make the coating property of the said sol-gel coat layer forming coating liquid favorable. Therefore, a uniform film without uneven coating can be formed, and a gas barrier film having good barrier properties against oxygen and water vapor can be obtained.

  In addition, about the gas barrier layer formation process, since the formation method of the gas barrier layer was described in the term of the gas barrier layer of "A. gas barrier film" mentioned above, description here is abbreviate | omitted. Hereinafter, the sol-gel coat layer forming step will be described.

1. Sol gel coat layer forming step In the sol gel coat layer forming step of the present invention, an organometallic compound hydrolyzate or M ₂ O · nSiO ₂ (M is a lithium or a plurality of lithium containing lithium) is formed on a gas barrier layer formed on a substrate. A coating solution for forming a sol-gel coating layer containing an alkali metal polysilicate represented by a molar ratio of 1 to 20 and a saccharide, and a saccharide, and cured by a sol-gel reaction to form a sol-gel coating It is a process of forming a layer.

In the present invention, the viscosity of the coating solution for forming a sol-gel coating layer is in the range of 1 Pa · s to 1000 Pa · s at 25 ° C., particularly in the range of 5 Pa · s to 800 Pa · s, particularly 10 Pa · s. It is preferable to be within a range of ˜500 Pa · s. If the viscosity of the sol-gel coat layer forming coating solution exceeds the above range, there will be a problem in coating properties, and it may be difficult to form a uniform film and a gas barrier film having good gas barrier properties may not be obtained. Because there is. On the other hand, if the viscosity of the sol-gel coat layer forming coating solution is less than the above range, it may not be possible to expect an improvement in the adhesion between the formed sol-gel coat layer and the gas barrier layer.
The viscosity of the sol-gel coat layer forming coating solution may be a value measured at a temperature of 25 ° C. using a B-type viscometer (visco-mate model DD-1 manufactured by Yamaichi Denki).

  The sol-gel coating layer forming coating solution contains a hydrolyzate of the organometallic compound or the alkali metal polysilicate, and the saccharide, and is prepared by diluting these with a solvent. is there. Examples of such solvents include water; alcohols such as isopropyl alcohol, methanol and ethanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; toluene and xylene. Aromatic hydrocarbons such as, etc .; or mixtures thereof are preferably used.

  The solid content concentration of the sol-gel coat layer forming coating solution is prepared such that the viscosity is within the above range. Specifically, the solid content concentration of the coating liquid for forming the sol-gel coat layer is specifically within a range of 0.01% by mass to 50% by mass, particularly within a range of 0.05% by mass to 25% by mass, particularly 0.1%. It is preferable to be in the range of 10% by mass to 10% by mass.

  Furthermore, the sol-gel coat layer forming coating liquid of the present invention is a filler, a mold release agent, a surface treatment agent, a flame retardant, a plasticizer, an antibacterial agent, as long as the effect of the present invention is not impaired. It may contain an antifungal agent, a leveling agent, an antifoaming agent, a colorant, a stabilizer, a coupling agent and the like.

  When preparing the coating solution for forming the sol-gel coat layer, for example, an aqueous solution of saccharide and an aqueous solution of alkali silicate, an aqueous solution of saccharide and an organic metal compound, or an aqueous solution of saccharide and an organic metal compound are mixed. Can be mixed with those hydrolyzed in advance.

  The application method of the coating solution for forming the sol-gel coat layer is not particularly limited as long as it can be applied on the gas barrier layer. For example, bar coating, dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, A die coating, a screen printing method, a spray coating, a gravure offset method, or the like can be used. Among the above, for example, when applied to a film-like substrate, bar coating, gravure coating, die coating, and gravure offset method are preferably used, and gravure coating is preferably used particularly considering production efficiency and cost. It is done.

After the sol-gel coating layer forming coating solution is applied, it is cured by dehydration polycondensation by a sol-gel reaction to form a film. The applied coating solution for forming a sol-gel coat layer can be cured by heating and drying. The method for heating and drying the sol-gel coating layer forming coating liquid is not particularly limited as long as it is a method capable of curing the sol-gel coating layer forming coating liquid applied on the substrate. Examples thereof include a method using hot air drying, hot roll drying, infrared irradiation and the like.
In addition, the temperature at this time is not particularly limited as long as it is a temperature at which the sol-gel coating layer forming coating solution can be cured, and the heat drying method, the type of solvent, the alkali metal polysilicate used, and the like Although it varies depending on the kind and content of the sol-gel reaction component, it is usually in the range of 80 ° C to 200 ° C, preferably 100 ° C to 150 ° C. The heating time is not particularly limited as long as it can cure the sol-gel coat layer forming coating solution in the same manner as described above, and the heating drying method, the type of solvent, and the alkali metal polymer used. Although it varies depending on the kind and content of the sol-gel reaction component such as silicate, it can be set in about 1 to 120 minutes, and preferably in the range of 5 to 60 minutes.
The sol-gel coat layer can be formed by curing the sol-gel coat layer-forming coating solution under such reaction conditions.

  The hydrolyzate of the organometallic compound, the alkali metal polysilicate, and the saccharide are described in the above-mentioned section “A. Gas barrier film”, and thus the description thereof is omitted here.

2. Other Steps In the present invention, the step is not particularly limited as long as it has the gas barrier layer forming step and the sol-gel coat layer forming step. For example, an anchor layer forming step for forming an anchor layer on a substrate, Other steps may be appropriately included as necessary, such as an overcoat layer forming step of forming an overcoat layer on the sol-gel coat layer.

  About such an anchor layer formation process and an overcoat layer formation process, since the formation method of an anchor layer and the formation method of an overcoat layer were described in the above-mentioned item of "A. gas barrier film", explanation here is omitted. To do.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described using examples and comparative examples.

(Preparation of sol-gel coating solution)
To 10 g of a lithium silicate aqueous solution (Li ₂ O.nSiO ₂ , n = about 5 mol ratio) adjusted to a solid content of 10 wt%, tetraethyl orthosilicate (Si (OC ₂ H ₅ ) ₄ : abbreviated as TEOS) 8.3 g (0. 04 mol), 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (Sisso Siler Ace S530) (9.9 g, 0.04 mol) and 0.1 N hydrochloric acid (18 g) were added and stirred for 18 hours. A coating solution was prepared.
(Preparation of sugar solution)
A 5% aqueous solution of amylouronic acid was prepared and used as a saccharide solution.

[Example 1]
(Gas barrier layer formation process)
As a substrate, a biaxially stretched polyester film (manufactured by Unitika Ltd., Emblet PET12, thickness 12 μm) was used. Next, after evacuating until the ultimate vacuum of the chamber reaches 3.0 × 10 ⁻⁵ torr (4.0 × 10 ⁻³ Pa) using a wind-up type vacuum vapor deposition apparatus, oxygen gas is removed from the coating drum. In the vicinity, the pressure inside the chamber is introduced at 3.0 × 10 ⁻⁴ torr (4.0 × 10 ⁻² Pa), and the silicon monoxide of the evaporation source is supplied with a power of about 10 kw by a pierce-type electron gun. A silicon oxide gas barrier layer having a thickness of 500 mm was formed on a polyester film that was heated and evaporated to run on a coating drum at a speed of 120 m / min.
(Sol-gel coat layer forming process)
The sol-gel coat solution and the saccharide solution were mixed at a weight ratio of 5: 5 to prepare a sol-gel coat layer forming coating solution. This sol-gel coating layer forming coating solution is bar-coated on the gas barrier layer so that the thickness of the dried film becomes about 1 μm, and heat-treated at 100 ° C. for 30 minutes to form a sol-gel coating layer. Got.

[Example 2]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coat layer was formed on the gas barrier layer in the same manner as in Example 1 except that the weight ratio of the sol-gel coat solution and the saccharide solution was set to 2: 8 to obtain a gas barrier film.

[Example 3]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coating layer was formed on the gas barrier layer in the same manner as in Example 1 except that the weight ratio of the sol-gel coating solution and the saccharide solution was 8: 2, and a gas barrier film was obtained.

[Example 4]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coating layer forming coating solution was prepared in the same manner as in Example 1. A gas barrier film was obtained in the same manner as in Example 1 except that this sol-gel coating layer forming coating solution was bar-coated on the gas barrier layer so that the thickness of the dried film was about 0.01 μm. .

[Example 5]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coating layer forming coating solution was prepared in the same manner as in Example 1. A gas barrier film was obtained in the same manner as in Example 1 except that this sol-gel coating layer-forming coating solution was bar-coated on the gas barrier layer so that the thickness of the dried film was about 20 μm.

[Comparative Example 1]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coating layer forming coating solution was prepared using only a saccharide solution, and a sol-gel coating layer was formed on the gas barrier layer in the same manner as in Example 1 to obtain a gas barrier film.

[Comparative Example 2]
In the same manner as in Example 1, a gas barrier layer was formed on the substrate.
Next, a sol-gel coating layer forming coating solution was prepared using only the sol-gel coating solution, and a sol-gel coating layer was formed on the gas barrier layer in the same manner as in Example 1 to obtain a gas barrier film.

[Evaluation]
The results of evaluating the properties of the obtained gas barrier film are shown in Table 1 below. The oxygen transmission rate and water vapor transmission rate were measured by the methods described above. Moreover, the total light transmittance was made into the average value of the value measured using Nippon Denshoku Co., Ltd. haze meter NDH2000.

It is a schematic sectional drawing which shows an example of the gas barrier film of this invention. It is a schematic sectional drawing which shows the other example of the gas barrier film of this invention. It is a schematic sectional drawing which shows the other example of the gas barrier film of this invention. It is a schematic sectional drawing which shows the other example of the gas barrier film of this invention. It is a schematic sectional drawing which shows the other example of the gas barrier film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas barrier film 2 ... Base material 3 ... Gas barrier layer 4 ... Sol gel coating layer 6 ... Anchor layer 7 ... Overcoat layer

Claims (6)

A base material, a gas barrier layer formed on at least one surface of the base material and made of a vapor deposition film, and a hydrolyzate of an organometallic compound or M ₂ O.nSiO ₂ (M is lithium Or a plurality of alkali metals including lithium, n is an alkali metal polysilicate represented by a molar ratio in the range of 1 to 20, and a sol-gel coat layer formed of a saccharide-containing film. the film.   2. The gas barrier film according to claim 1, wherein a weight average molecular weight of the saccharide is in a range of 1 to 5 million.   3. The gas barrier film according to claim 1, wherein a film thickness of the sol-gel coat layer is in a range of 0.01 μm to 50 μm.   The gas barrier film according to any one of claims 1 to 3, wherein an anchor layer is formed between the base material and the gas barrier layer.   The gas barrier film according to any one of claims 1 to 4, wherein an overcoat layer is formed on the sol-gel coat layer. A gas barrier layer forming step of forming a gas barrier layer on the substrate by vapor deposition;
On the gas barrier layer, an alkali metal compound hydrolyzate or an alkali represented by M ₂ O.nSiO ₂ (M is lithium or a plurality of alkali metals containing lithium, and n is in a molar ratio of 1 to 20). A method for producing a gas barrier film, comprising: applying a coating solution for forming a sol-gel coat layer containing a metal polysilicate and a saccharide, and curing the sol-gel coat layer by forming a sol-gel coat layer by sol-gel reaction,
The method for producing a gas barrier film, wherein the sol-gel coating layer forming coating solution has a viscosity of 1 Pa · s to 1000 Pa · s at 25 ° C.

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