JP2007098646A - Gas barrier film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier film improved in gas barrier properties against oxygen or steam. <P>SOLUTION: The gas barrier film comprises: a base material; the gas barrier layer, which comprises a vapor deposition film, formed at least on one side of the base material; and sol-gel coating layer formed on the gas barrier layer and comprising a film containing a hydrolysate of an organometal compound or an alkali metal polysilicate represented by 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 an inorganic layered compound. The thickness of the sol-gel coating layer is 0.01-50 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas barrier film mainly used as a packaging material for foods, pharmaceuticals and the like and a packaging material for electronic devices, for example.

  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 during 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 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, as a gas barrier film realizing high barrier properties, a method of depositing an inorganic oxide such as silicon oxide by a vacuum deposition method (for example, see Patent Document 1) has been proposed. 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 containing lithium, and n is in a molar ratio of 1 to 20), and a film containing an inorganic layered compound The gas barrier film is characterized in that the film thickness of the sol-gel coat layer is in the range of 0.01 μm to 50 μm.

  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 a sol-gel coating layer, and defects can be compensated. Therefore, it is possible to prevent the gas barrier property of the gas barrier layer from being lowered due to the influence of the defects. According to the invention, since the sol-gel coat layer contains a hydrolyzate of an organometallic compound or an alkali metal polysilicate, the gas barrier layer of the sol-gel coat layer forming coating solution used for forming the sol-gel coat layer is used. The affinity for can be increased. Accordingly, it becomes possible to improve the coating property of the coating solution for forming the sol-gel coating layer and the film-forming property of the sol-gel coating layer when forming the sol-gel coating layer, and the adhesion between the sol-gel coating layer and the gas barrier layer. Can be improved. Furthermore, according to the present invention, the sol-gel coat layer contains an inorganic layered compound, and since this inorganic layered compound has a layered structure in which the layers overlap each other, it allows permeation of gases such as oxygen and water vapor. It becomes possible to block. Therefore, in the sol-gel coat layer, gas passes through so as to avoid the inorganic layered compound, so that a maze effect can be expected and gas barrier properties can be improved. Moreover, when the film thickness of the sol-gel coat layer is within the above range, it is possible to prevent cracks and the like from being generated during the formation of the sol-gel coat layer, and to suppress a decrease in gas barrier properties. Thus, in this invention, it becomes possible to improve the gas barrier property of a gas barrier film by providing a sol-gel coat layer on a gas barrier layer. 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 increased during film formation of the sol-gel coat layer, which is advantageous in the manufacturing process. In general, since the inorganic layered compound is a colored compound such as white like a clay mineral, the sol-gel coat layer can be colored by adding the inorganic layered compound to the sol-gel coat layer. There is also an advantage that the gas barrier film can be concealed. In addition, the inorganic layered compound often has a hydrophilic surface, and is compatible with the hydrolyzate of the organometallic compound and the alkali metal polysilicate. For this reason, the hydrolyzate of the organometallic compound and the alkali metal polysilicate enter between the layers of the inorganic layered compound, and the layers of the inorganic layered compound are filled. Thereby, the effect of the inorganic layered compound blocking the gas is enhanced, and as a result, the gas barrier property of the gas barrier film can be improved.

  In the present invention, the sol-gel coating layer may contain a water-soluble polymer. This is because by incorporating the water-soluble polymer in the sol-gel coat layer, the adhesion with the gas barrier layer can be improved. Also, by including a water-soluble polymer, good film formability and flexibility can be imparted, and cracks and the like can be prevented from occurring during curing shrinkage due to drying during film formation of the sol-gel coat layer. Is possible. Thereby, very high gas barrier property can be provided to a gas barrier film.

  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.

  Furthermore, 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.

  According to the present invention, the defects derived from micropores such as cracks and pinholes possessed by the gas barrier layer made of the vapor-deposited film are eliminated by coating with a sol-gel coat layer containing an inorganic layered compound, which is conventionally difficult to reach. The gas barrier film having a high level of gas barrier properties can be obtained.

  Hereinafter, the gas barrier film of the present invention will be described in detail.

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 a film containing 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 molar ratio), and an inorganic layered compound The film thickness of the sol-gel coat layer is within a predetermined range.

  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 has a base material 2, a gas barrier layer 3 formed on the base material 2, and a sol-gel coat layer 4 formed so as to be in contact with the gas barrier layer 3. Is.

  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.

  Further, since the sol-gel coat layer in the present invention is a layer containing a hydrolyzate of an organometallic compound or an alkali metal polysilicate, the above gas barrier layer of the sol-gel coat layer forming coating liquid used for forming the sol-gel coat layer The affinity for can be increased. 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.

  In addition, the sol-gel coat layer in the present invention contains an inorganic layered compound, and this inorganic layered compound has a layer in which atoms and atomic groups are arranged in a plane and overlaps in a direction perpendicular to the plane. It has a layered structure. A schematic diagram of a sol-gel coat layer containing such an inorganic layered compound is shown in FIG. As shown in FIG. 2, the presence of the inorganic layered compound L in the sol-gel coat layer 4 allows the inorganic layered compound L to block the transmission of gases such as oxygen and water vapor. Gas passes through so as to avoid the inorganic layered compound L. Therefore, in this invention, the gas barrier property of a gas barrier film can be improved by containing an inorganic layered compound in a sol-gel coat layer.

  In general, when the film thickness of the sol-gel coat layer formed by the sol-gel reaction is too thick, cracks and the like are likely to occur during curing shrinkage due to drying when forming the sol-gel coat layer. Since the film thickness of the sol-gel coat layer in the invention is within the above range, it is possible to prevent the occurrence of such cracks and the like and to suppress the deterioration of gas barrier properties. Furthermore, 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, since the inorganic layered compound contained in the sol-gel coat layer in the present invention is often a white or other colored compound such as a clay mineral, the sol-gel coat layer contains the sol-gel coat layer. Can be colored. Further, by changing the film thickness of the sol-gel coating layer, it is possible to appropriately adjust from a transparent material to a material having high whiteness. Therefore, by including an inorganic layered compound in the sol-gel coat layer, it can be used as a gas barrier film having design properties and concealing properties.

In general, the inorganic layered compound often has a hydrophilic surface, and is compatible with the hydrolyzate of the organometallic compound and the alkali metal polysilicate. For this reason, the hydrolyzate of the organometallic compound and the alkali metal polysilicate enter between the layers of the inorganic layered compound, and the layers of the inorganic layered compound are filled. Thereby, the effect of the inorganic layered compound blocking the gas is enhanced, and as a result, the gas barrier property of the gas barrier film 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 a film containing an alkali metal polysilicate represented by a molar ratio of 1 to 20 and an inorganic layered compound.

  The inorganic layered compound refers to a crystalline inorganic compound having a layered structure, and examples thereof include kaolinite group, smectite group, mica group and other clay minerals. As long as it is an inorganic layered compound, its type, particle size, aspect ratio and the like can be appropriately selected according to the purpose of use of the gas barrier film, and are not particularly limited. In general, examples of the smectite group inorganic layered compound include montmorillonite, hectorite, and saponite, and examples of the inorganic layered compound mainly composed of montmorillonite include bentonite. Among these, processing to nanosize is easier than other compounds, industrialization has been carried out, and because of cost advantages, montmorillonite, bentonite, etc. are preferably used, especially montmorillonite, It is preferably used from the viewpoints of stability in the sol-gel coating layer forming coating solution used when forming the sol-gel coating layer, coating properties, and the like.

  The content of such an inorganic layered compound is in the range of 0.1% by mass to 30% by mass in the sol-gel coat layer, in particular in the range of 1% by mass to 20% by mass, particularly 5% by mass to 15% by mass. It is preferable to be within the range. Thereby, a gas barrier film having good gas barrier properties can be obtained. In addition, when content of an inorganic stratiform compound is less than the said range, the improvement of gas barrier property and the concealment effect may not be expectable. When the content of the inorganic layered compound exceeds the above range, it is difficult to obtain a good coating property of the sol-gel coating layer forming liquid when forming the sol-gel coating layer, and the sol-gel coating layer has a film forming property. This is because it may become insufficient and it may be difficult to form a uniform film.

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.

  In the present invention, the sol-gel coat layer may contain a water-soluble polymer. It is because it becomes possible to improve adhesiveness with a gas barrier layer by containing a water-soluble polymer. Also, by including a water-soluble polymer, good film formability and flexibility can be imparted, and cracks and the like can be prevented from occurring during curing shrinkage due to drying during film formation of the sol-gel coat layer. Is possible. Thereby, very high gas barrier property can be provided to a gas barrier film.

  Examples of such water-soluble polymers include polyvinyl alcohol or derivatives thereof, polyethyleneimine or derivatives thereof, ethylene-vinyl alcohol copolymers, starch, sugars of celluloses, polyacrylic acid, polymethacrylic acid, or copolymers thereof. A coalescence etc. can be mentioned. Among these, polyvinyl alcohol is widely used as a water-soluble polymer, and is preferably used because it can realize high gas barrier properties.

  Here, the film thickness of such a sol-gel coating layer is in the range of 0.01 μm to 50 μm. In the present invention, the film thickness is in the range of 0.1 μm to 10 μm, particularly 0.5 μm to 5 μm. It is preferable to be within the range. 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.

  As the method for forming the sol-gel coat layer, a sol-gel coat layer-forming coating solution (sol solution) is prepared from the above-described materials, the sol-gel coat layer-forming coating solution is applied onto the gas barrier layer, and dried by heating. Can be formed. At this time, the applied coating liquid for forming a sol-gel coating layer is formed by dehydration polycondensation by a sol-gel reaction. As a coating method, 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, bar coating and the like can be used. The heat drying method is not particularly limited, such as hot air drying, hot roll drying, and infrared irradiation.

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 film 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 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. 3, 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. 4, a three-layer configuration in which the gas barrier layer 3, the sol-gel coat layer 4, and the 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.

  Further, for example, as shown in FIG. 5, 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. Generally, when a vapor deposition film is formed directly on a substrate having high flexibility or the like, cracks 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. 6, a four-layer configuration 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 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 laminated repeatedly. Even if a multilayer structure is used, the thickness of the entire 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. .
Here, the oxygen permeability was measured using an oxygen gas permeability measuring apparatus (manufactured by Modern Control Co., Ltd., OXTRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a humidity of 90% Rh. 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 both the high gas barrier property and impact resistance, it can be used, for example as a base material for various displays and various displays. It can also be used for solar cell cover films and the like.

  When the gas barrier film of the present invention is used for covering a display, the gas barrier film may be laminated on one side of the display, may be laminated on both sides, or the entire circumference of two gas barrier films laminated on both sides is sealed. And may be sealed. When the gas barrier film is laminated on one side of the display, it is possible to provide a display with improved gas barrier properties on the side where the gas barrier film of the display is laminated. Further, when the gas barrier film is laminated on both sides of the display, a display having improved gas barrier properties on both sides of the display can be provided. Furthermore, when the entire periphery of the two gas barrier films laminated on both sides of the display is sealed and sealed, a display capable of maintaining high gas barrier properties can be provided.

  When the gas barrier film of the present invention is used as a display substrate, the gas barrier film can be used as a substrate on at least the viewing side of the display element. Thereby, although the layer for exhibiting gas barrier property increases, the display which can maintain gas barrier property highly can be provided, without accompanying the substantial increase in thickness.

  A display on which the gas barrier film of the present invention as described above is laminated or a display using the gas barrier film of the present invention as a base material can be used as a liquid crystal display panel or an organic EL element. When the display is used as a liquid crystal display panel, a display element capable of stably maintaining the characteristics of the liquid crystal display for a long period can be provided. Further, when the display is used as an organic EL element, it is possible to provide a display that can stably maintain the characteristics of the organic EL element for a long period of time and can suppress generation and growth of dark spots.

  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, and the sol-gel coating solution was added. Was prepared.
(Preparation of inorganic layered compound-containing coating solution)
Unitika Chemical's polyvinyl alcohol UF040G (saponification degree 99%, average polymerization degree 400) was dissolved in pure water to obtain a 20% aqueous solution. To this aqueous solution, montmorillonite (manufactured by Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was added so as to be 10 wt% with respect to the total amount of solid content, and stirred to prepare an inorganic layered compound-containing coating solution.

[Example 1]
(Formation of gas barrier layer)
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.
(Formation of sol-gel coating layer)
Using the sol-gel coating solution and the inorganic layered compound-containing coating solution, the sol-gel coating solution: inorganic layered compound-containing coating solution was prepared to have a ratio of 5: 5 (weight ratio). Obtained. 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 gas barrier layer was formed in the same manner as in Example 1 except that the ratio of the sol-gel coating solution and the inorganic layered compound-containing coating solution was sol-gel coating solution: inorganic layered compound-containing coating solution = 2: 8 (weight ratio). A sol-gel coating layer was formed on top 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 gas barrier layer was formed in the same manner as in Example 1 except that the ratio of the sol-gel coating solution and the inorganic layered compound-containing coating solution was sol-gel coating solution: inorganic layered compound-containing coating solution = 8: 2 (weight ratio). A sol-gel coating layer was formed on top to obtain a gas barrier film.

[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 (sol-gel coating solution: inorganic layered compound-containing coating solution = 0: 10 (weight ratio)) was prepared without using a sol-gel coating solution, and in the same manner as in Example 1, A sol-gel coat layer was formed on the gas barrier layer 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 coating solution for forming a sol-gel coating layer (sol-gel coating solution: inorganic layered compound-containing coating solution = 10: 0 (weight ratio)) was prepared without using the inorganic layered compound-containing coating solution. Thus, a sol-gel coat layer was formed on the gas barrier layer 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 permeability is measured using an oxygen gas permeability measuring device (Modern Control Co., Ltd., OXTRAN 2/20), and the water vapor permeability is measured using a water vapor gas permeability measuring device (Modern Control Co., Ltd., PERMATRAN-W 3/31). Moreover, the total light transmittance was taken as 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 diagram for demonstrating the sol-gel coat layer in 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 (4)

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 a sol-gel coating layer made of a film containing an alkali metal polysilicate represented by a molar ratio of 1 to 20) and an inorganic layered compound, and the sol-gel A gas barrier film, wherein the coating layer has a thickness in the range of 0.01 μm to 50 μm.   The gas barrier film according to claim 1, wherein the sol-gel coat layer contains a water-soluble polymer.   The gas barrier film according to claim 1, 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 3, wherein an overcoat layer is formed on the sol-gel coat layer.

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