JP2022000333A - Transparent gas barrier film - Google Patents

Abstract

To provide a transparent gas barrier film that has an excellent oxygen barrier property not only before bending but also after bending and has a high water-wetting adhesion strength, a laminated material using the same, a bag-shaped container, and a paper container.SOLUTION: There is provided a transparent gas barrier film that is a laminate having an inorganic compound layer and a protective layer on at least one side of a base film in this order from the base film side, in which the protective layer contains a vinyl alcohol-based resin containing a cyclic compound structure having a carbonyl group in the cyclic structure, and a linear polysiloxane, a ratio between vinyl alcohol resin and polysiloxane on a solid content mass is 15/85 to 85/15, a ratio (A/B) on an acid permeability before and after bending between an oxygen permeability (B) before bending and an oxygen permeability (A) after bending is 1.0 to 2.0, and a water-wetting adhesion strength is 2 N/15 mm or more.SELECTED DRAWING: None

Description

In the present invention, a transparent gas barrier film having a small increase in oxygen permeability due to bending, an excellent oxygen barrier property even after bending, and a high water-wet adhesion strength, a laminated material using the transparent gas barrier film, and a bag using the laminated material are used. Regarding shaped containers and paper containers.

Various packaging materials have been used for packaging foods and drinks, pharmaceuticals, etc., and these packaging materials are required to have an oxygen barrier property in order to prevent deterioration of the contents due to oxidation. In particular, having an excellent gas barrier property can contribute to extending the expiration date and improving food safety. Aluminum foil can be mentioned as a packaging material having excellent gas barrier properties. However, since aluminum foil is not transparent, discoloration due to oxidation of the contents and contamination of foreign substances cannot be visually recognized, and a metal detector cannot be used. If metal is mixed in the contents, it cannot be detected, and if foreign matter is mixed between the aluminum foil and the bonding material, it cannot be confirmed by the defect detector in the bonding process. There are drawbacks.

In order to solve these problems, a vapor deposition film in which a vapor deposition film of an inorganic oxide such as aluminum oxide or silicon oxide is provided on a film such as polyester by a vacuum vapor deposition method or the like has been proposed. Since these inorganic oxides are transparent, they are transparent and the state of the contents can be visually recognized. However, since the inorganic oxide layer is hard, there is a problem that cracks and pinholes are generated due to bending, and the gas barrier property is remarkably lowered.

Therefore, by providing an inorganic compound layer such as silicon oxide or aluminum oxide on a resin film such as polyester and further polymer-coating the gas barrier layer on the resin film, both oxygen barrier property and water vapor barrier property are achieved. Barrier films are disclosed. As one of them, as a barrier film that reduces barrier deterioration due to high temperature humidification conditions or retort sterilization treatment, a vapor deposition film of an inorganic oxide such as aluminum oxide or silicon oxide is applied on a plastic base film by a vacuum vapor deposition method or the like. Further, a method for producing a transparent barrier laminated film by applying a coating agent containing a metal alkoxide and a polyvinyl alcohol-based resin and / or an ethylene / vinyl alcohol copolymer is disclosed.

Further, in the laminated material for paper containers, the barrier film and the paper base material in the laminated material or the resin layer resulting from the punching of the laminated material for paper containers into a blank plate in the box making process and the embossing of the ruled line molding for bending are performed. In the system of in-line box making from the laminated material for roll-shaped paper containers, the problem of peeling occurs, and in the processes such as bending, embossing, and cutting, interlayer adhesion and gas barrier property are provided against the same peeling problem. As the barrier film to have, a film in which an inorganic oxide vapor deposition layer, a barrier coat layer, an inorganic oxide vapor deposition layer, a base film, and an inorganic oxide vapor deposition layer are laminated in this order is disclosed (Patent Document 1).

In order to prevent cracks from occurring in the vapor-deposited film of inorganic oxides such as silicon oxide and aluminum oxide that make up the transparent barrier film as a barrier material, the surface of the protective film that makes up the barrier layer is paper. An outermost layer, a paper base material, an adhesive layer composed of a melt-extruded resin layer, and a vapor-deposited inorganic oxide film, a gas barrier coating film, and a polyolefin-based film on one surface of the base film so as to face the surface of the base material. Disclosed is a liquid paper container in which a barrier layer having a structure provided with a protective film and an innermost layer are sequentially laminated to form a laminated material, and the laminated material is used to manufacture a box. (Patent Document 2)
As a gas barrier film with excellent gas barrier properties, bending resistance, and long-term storage stability that can meet the required levels for electronic component applications, the main components are a metal oxide vapor-deposited layer on a film substrate and a polymer based on a silazane skeleton. A gas barrier film in which a first barrier coating layer and a second barrier coating layer containing a metal oxide polymer composed of a metal alkoxide as a main component are provided in this order and a method for producing the same are disclosed (Patent Documents). 3).

As a laminated material for gusset bags, standing pouches, inner bags of bag-in-box containers, paper liquid containers, cup-shaped containers, and tubular containers that must be formed by bending the gas barrier laminated material, an inorganic compound vapor deposition layer is used on the base material. Disclosed is a laminated material provided with a coating layer composed of a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof, or a coating layer composed of a water-soluble polymer and tin chloride, and laminated with a heat-sealing resin. (Patent Document 4).

As a method of suppressing deterioration of adhesion and gas barrier property when heat treatment such as retort sterilization and retort cooking is performed, metal vapor deposition having an average film thickness of 0.001 to 1.0 nm is performed on at least one surface of the base film surface. A layer is laminated, and a thin-film deposition layer made of an inorganic oxide having an average film thickness of 5 to 100 nm is laminated on the layer, and a water-soluble silicon-based resin having a thickness of 0.01 to 5 μm is further laminated on the layer. The gas barrier film is disclosed (Patent Document 5).

Japanese Unexamined Patent Publication No. 2019-107803 Japanese Unexamined Patent Publication No. 2002-154254 JP-A-2015-189137A Japanese Unexamined Patent Publication No. 8-216325 Japanese Unexamined Patent Publication No. 2009-23114

However, the technique of Patent Document 1 could not suppress the deterioration of the gas barrier property in the box making process. In addition, since there are many laminating processes, the manufacturing cost is high. In the technique of Patent Document 2, since the vapor-deposited film of the inorganic oxide, the gas barrier coating film, and the protective film are on the paper substrate side via the adhesive layer composed of the melt-extruded resin layer, the box is manufactured using this laminated material. In the liquid paper container, the end face of the base film having no gas barrier property is arranged in the folded-back seal part and the gassho seal part of the liquid container, and the substance is transferred to the inside of the liquid paper container through the base film having poor gas barrier property. It was not practically usable because it was possible to go back and forth between the outside and the contents were scattered and the contents were oxidized. In the technique of Patent Document 3, in order to exhibit gas barrier properties, a metal oxide vapor deposition layer, a first barrier coating layer containing a polymer based on a silazane skeleton as a main component, and a metal alkoxide are used on a film substrate. It is necessary to provide the second barrier coating layer containing the metal oxide polymer as a main component in this order, and there is a problem that there are many steps of layer formation and the manufacturing cost is high.

In the technique of Patent Document 4, the oxygen permeability before and after bending is not sufficiently low, and in order that peeling does not occur after bending of the container molding, it is necessary to have an anchor coat layer for vapor deposition of an inorganic compound on the base material. There was a problem that the cost was high. The technique of Patent Document 5 can suppress deterioration of adhesion and gas barrier property when heat treatment such as retort sterilization and retort cooking is performed, but gas barrier property and adhesion after severe bending during container molding can be suppressed. Was not enough.

Therefore, the present invention has a transparent gas barrier film having excellent oxygen barrier properties not only before bending but also after bending, and a transparent gas barrier film having high water-wet adhesion strength, a laminated material using the transparent gas barrier film, a bag-shaped container, and a paper container. The purpose is to provide.

In order to solve the above object, the transparent gas barrier film of the present invention is a laminate having an inorganic compound layer and a protective layer on at least one side of the base film in this order from the base film side, and the protection thereof. The layer contains a vinyl alcohol-based resin and a linear polysiloxane containing a cyclic compound structure having a carbonyl group in the cyclic structure, and the ratio of the solid content mass of the vinyl alcohol-based resin and the linear polysiloxane is 15/85. ~ 85/15, the oxygen permeability ratio (A / B) before and after bending of the oxygen permeability (B) before bending and the oxygen permeability (A) after bending is 1.0 to 2.0, and is wet with water. Adhesion strength is 2N / 15mm or more.

Further, it is a laminated material in which a plastic film and a heat-sealing resin layer are provided on at least one side of the above-mentioned transparent gas barrier film.

Further, it is a laminated material provided with a plastic film on at least one side of the above-mentioned transparent gas barrier film and a heat-sealing resin layer on the other side.

Further, it is a laminated material in which paper and a heat-sealing resin layer are provided on at least one side of the above-mentioned transparent gas barrier film, and a heat-sealing resin layer is provided on the other side.

Further, it is a bag-shaped container using the laminated material described in any of the above.

Further, it is a paper container using a laminated material in which paper and a heat-sealing resin layer are provided on at least one side of the above-mentioned transparent gas barrier film, and a heat-sealing resin layer is provided on the other side.

According to the present invention, a transparent gas barrier film having excellent oxygen barrier properties not only before bending but also after bending and having high water-wet adhesion strength, a laminated material using a transparent gas barrier film, a bag-shaped container, and a paper container. Can be provided.

It is a schematic cross-sectional view of one Embodiment of the laminated material which provided the paper and the heat-bonding resin layer on one side, and the heat-bonding resin layer on the other side of the transparent gas film of this invention. This is a schematic description of a method of preparing a measurement sample for measuring the oxygen permeability of a transparent gas barrier film or a laminated material after bending.

The transparent gas barrier film of the present invention is a laminate having an inorganic compound layer and a protective layer on at least one side of the base film in this order from the base film side, and the protective layer has a carbonyl group in the cyclic structure. It contains a vinyl alcohol-based resin containing a cyclic compound structure and a linear polysiloxane, and the ratio of the solid content mass of the vinyl alcohol-based resin and the linear polysiloxane is 15/85 to 85/15, and before bending. The oxygen permeability ratio (A / B) of the oxygen permeability (B) and the oxygen permeability (A) after bending is 1.0 to 2.0 before and after bending, and the water-wet adhesion strength is 2N / 15 mm or more. ..

By setting the ratio of the solid content mass of the vinyl alcohol resin and the linear polysiloxane to 15/85 to 85/15, the oxygen permeability (B) before bending and the oxygen permeability (A) after bending are bent. It is possible to obtain a transparent gas barrier film having an oxygen permeability ratio (A / B) of 1.0 to 2.0 before and after, and a water-wet adhesion strength of 2N / 15 mm or more, and having excellent bending resistance.

The vinyl alcohol-based resin is preferably a vinyl alcohol-based resin having a lactone structure, and the protective layer is preferably an organic-inorganic mixture layer, and the thickness of the protective layer is preferably 0.1 to 0.6 μm. Further, it is preferable that the surface of the base film of the early stage is ion-irradiated, the inorganic compound layer of the early stage contains aluminum oxide, and the film thickness is preferably 5 to 20 nm.

In the present invention, the base film is not particularly limited as long as the characteristics such as mechanical strength, heat resistance, and light resistance are taken into consideration depending on the application, but typical examples are polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene 2. , Polyester such as 6-naphthalate, polyvinyl alcohol, saponified ethylene / vinyl acetate copolymer, polystyrene, polycarbonate, polyethylene, polypropylene such as polypropylene, polyamide such as 6 nylon and 12 nylon, aromatic polyamide, polyimide and the like alone weight Examples thereof include films and sheets made of coalesced or copolymers. It is preferable that the film is more suitable for vapor deposition and has dimensional stability and heat resistance. From the above viewpoint, as the base film used for the transparent gas barrier film of the present invention, a polyethylene terephthalate film arbitrarily stretched in the biaxial direction is more preferably used, and a biaxially stretched polyethylene terephthalate film is preferable from the viewpoint of economy. .. The thickness of the base film is selected in the range of 6 to 16 μm from the viewpoint of vapor deposition processing suitability and economy, depending on the purpose. Further, the surface of these base films may be subjected to surface modification treatment such as corona treatment, flame treatment, plasma treatment, ion treatment, and anchor coating. As the plasma treatment, a method of performing plasma treatment with a planar magnetron type plasma treatment electrode while continuously running the base film is preferable. The planar magnetron type plasma processing electrode is a planar magnetron type plasma processing electrode in which a magnetic field is generated on the surface of the electrode by arranging a magnet on the back surface side of the planar (flat plate) plasma processing electrode, and electrons in the plasma are along the magnetic field. It is based on a method that maintains a steady discharge (magnetron plasma) by performing cycloid movement or trochoid movement in the form of wrapping around the magnetic field lines by Lorentz force. The magnet should be designed so that, for example, an S pole is arranged in the center and an N pole of the corresponding strength is arranged around the magnet so that the electrons can orbit the electrode surface while performing the above drift motion while winding around the magnetic field lines. Is preferable, and a strong plasma can be generated along a loop-shaped path through which the electrons can orbit. Depending on the shape of the electrode, the above-mentioned strong plasma generation region may be donut-shaped, elliptical or oblong. The discharge is preferably performed under a vacuum of 0.1 to 100 Pa by supplying a specific gas to the space including the planar magnetron type plasma processing electrode and the base film, and the electrode (casod) and the anod (earth). ) Discharge between. A stable discharge can be obtained by setting the pressure to 0.1 Pa or more. Further, by setting the value to 100 Pa or less, plasma processing can be efficiently performed. It is more preferably 0.1 to 50 Pa, still more preferably 0.1 to 20 Pa. The specific gas is selected depending on the purpose of plasma treatment, but is preferably at least one selected from oxygen, nitrogen, argon, helium, and water vapor, or a mixed gas thereof, and more preferably oxygen and nitrogen. , Or a mixed gas of these. It is preferable that the material of the planar magnetron electrode is a non-magnetic metal material such as copper, chromium, tin, silver, gold, and titanium because a strong magnetic field can be generated on the electrode surface, and a copper electrode is particularly used. If so, the efficiency of plasma treatment can be increased, which is more preferable because the electrode material is inexpensive. Further, as the ion treatment, it is preferable to irradiate the surface of the substrate fill with an ion beam by using a charged particle irradiation device of an anode layer type ion source. The anode layer type ion source is provided with a circumferential or racetrack-shaped slit in the front surface thereof, and a magnet for forming a magnetic field in the gap between the slits and an anode capable of applying a high voltage inside the slit. By supplying gas from a gas supply source and applying a high voltage to the anode, an ion beam can be irradiated from the slit. As the type of gas, oxygen, nitrogen, argon, helium and the like can be used.

In the present invention, ion treatment is particularly preferable as the treatment of the surface of the base film. An object of the surface treatment of the base film is to tightly bond the base film and the inorganic compound layer of the present invention. The surface of the base film may be ion-treated to continuously form an inorganic compound layer, or the surface of the base film may be ion-treated, wound once, and again in a vacuum chamber after the ion treatment. The base film of the above may be unwound to form an inorganic compound layer. While transporting a film having a predetermined width at a predetermined speed, the surface of the film is treated with ions generated from an ion generation source. At that time, it is presumed that a part of the polymer of the base film is decomposed by the energy of the generated ions and oxygen and hydrogen in the molecular chain are eliminated to form a carbon-rich layer. The carbon-rich layer formed by ions is difficult to move, maintains a strong bond with the metal oxide layer, and can ensure the adhesion of the metal oxide layer. Oxygen gas is evenly introduced in the width direction between the anode and cathode gaps in the ion generation source. ^{The amount of oxygen gas to be introduced is preferably 1.2 to 4.0 (cc · s / (min · m 2} )) in terms of the oxygen gas coefficient represented by the formula (1). When the value of the oxygen gas coefficient is smaller than 1.2 (cc · s / (min · m ² )), the degree of treatment on the surface of the base film is small, the bond with the inorganic compound layer is weakened, and the base film is formed. When the adhesion strength between the material film and the inorganic compound layer becomes insufficient and becomes ^{larger than 4.0 (cc · s / (min · m 2} )), the film has a brown appearance and the transparency is impaired. The pressure in the ion generation source ^{is preferably 2.5 × 10 -1} Pa or less. When it becomes larger than 2.5 × ^10-1 Pa, the high-speed ions emitted from the inside of the ion source lose energy due to collision with the residual gas before being irradiated on the base film, and the degree of surface treatment of the base film is lost. Is reduced, and the adhesion strength with the inorganic compound layer becomes insufficient.

When generating ions from an ion generation source, the anode voltage and anode current so that the anode power coefficient shown in equation (2) is 0.050 to 0.195 (kV · A · s / m ^{2) in the high-voltage power supply.} It is preferable to set. The power supply method may be any of a direct current type, an alternating current type, and a pulse type, but the direct current type is preferable. When the treatment with an anode power coefficient exceeding 0.195 is performed, the film has a brown appearance and the transparency is impaired, and when the treatment with an anode power coefficient less than 0.050 is performed, the base film The surface layer treatment is reduced, the bond between the base film and the inorganic compound layer is weakened, and the adhesion strength between the base film and the inorganic compound layer becomes insufficient.

Oxygen gas coefficient = oxygen gas (cc / min) / {film width (m) x transport speed (m / s)} ... Equation (1)
Anode power coefficient = {voltage (kV) x current (A)} / {film width (m) x transport speed (m / s)} ... Equation (2).

In the present invention, the inorganic compound layer is preferably an inorganic compound layer composed of a vapor-deposited layer such as aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof and having gas barrier performance. Of these, aluminum oxide is more preferable in consideration of processing suitability and gas barrier performance. The method for laminating the inorganic compound layer on the base film is not particularly limited, but a reactive vapor deposition method in which metallic aluminum is directly heated and evaporated to form an aluminum oxide layer by reaction with oxygen gas. Known methods such as an ion plating method in an oxygen gas atmosphere, a sputtering method using an aluminum oxide target, a reactive sputtering method using a metallic aluminum target to react with oxygen gas, and a chemical vapor deposition method can be used.

In the present invention, the film thickness of the inorganic compound is preferably 5 to 20 nm. If it is less than 5 nm, the gas barrier property before bending may be insufficient. On the other hand, if it exceeds 20 nm, the inorganic compound layer is cracked at the time of bending, and the oxygen permeability increases.

In the present invention, the protective layer contains a vinyl alcohol-based resin, the vinyl alcohol-based resin contains a cyclic compound structure having a carbonyl group in the cyclic structure, and further contains a linear polysiloxane as an inorganic component. It is an organic-inorganic mixture layer. Since the vinyl alcohol-based resin contains a cyclic compound structure having a carbonyl group in the cyclic structure, the hydrophobicity of the cyclic structure and the interaction around the resin by the carbonyl group result in a dense film structure and improved water resistance. .. In addition, it contains linear polysiloxane as an inorganic component, and by forming and immobilizing a network with a vinyl alcohol-based resin in an organic-inorganic mixture layer, it becomes a protective layer with a flexible and dense film structure and has excellent bending resistance. It is possible to develop the gas barrier performance.

As the protective layer, a coating liquid consisting of a vinyl alcohol-based resin having a high affinity for the inorganic compound layer and an aqueous solution containing either an organic silicon compound having an alkoxy group or a hydrolyzate thereof or an alcohol mixed aqueous solution is used. It is formed.

The vinyl alcohol-based resin as the main agent for forming the organic-inorganic mixture layer is not particularly limited as long as it is a vinyl alcohol-based resin such as polyvinyl alcohol, ethylene vinyl alcohol, and modified polyvinyl alcohol. Among them, polyvinyl alcohol is particularly preferable because it has excellent gas barrier properties when it is used in the coating liquid of the present invention. The polyvinyl alcohol referred to here is generally obtained by saponifying polyvinyl acetate, and may be partially saponified obtained by saponifying a part of acetic acid groups or completely saponified, but the degree of saponification is high. Is preferably higher. The degree of saponification is preferably 90% or more, more preferably 95% or more. If the degree of saponification is low and a large amount of acetic acid groups with large steric hindrance are contained, the free volume of the layer may increase. Therefore, the degree of polymerization of polyvinyl alcohol is preferably 1,000 or more and 3,000 or less, and more preferably 1,000 or more and 2,000 or less. When the degree of polymerization is low, the polymer is difficult to fix and the water resistance may decrease.

As described above, the vinyl alcohol-based resin in the present invention contains a cyclic compound structure having a carbonyl group in the cyclic structure. The cyclic structure is not particularly limited as long as it is a three-membered ring or more (for example, a three- to six-membered ring), and a heteroelement such as nitrogen, oxygen, sulfur, or phosphorus other than carbon is contained in the cyclic structure. It may be a cyclic compound structure such as a heterocycle having a heterocyclic structure. Further, the site having this cyclic compound structure may be present in any of the main chain, the side chain, and the crosslinked chain in the vinyl alcohol-based resin. Specific examples of the cyclic compound structure having a carbonyl group in these cyclic structures include a lactone structure which is a cyclic ester and a lactam structure which is a cyclic amide, and these include two or more kinds even if they are used alone. It may be, but is not particularly limited, and preferably has a lactone structure. The lactone structure is stable against the acid catalyst used for high-temperature hot water treatment and hydrolysis of alkoxysilane, which will be described later, and the gas barrier property is stable. Examples of those having a lactone structure include α-acetolactone, β-propiolactone, γ-butyrolactone, and δ-valerolactone.

In the present invention, a method for producing a vinyl alcohol-based resin containing a cyclic compound structure having a carbonyl group in the cyclic structure is a main chain of the vinyl alcohol-based resin as disclosed in Japanese Patent Publication No. 2010-533760. A method of reacting a hydroxy group and a carboxyl group in the resin to form an ester bond, a method of copolymerizing a vinyl monomer having a specific cyclic compound structural group disclosed in JP-A-2003-105154, and JP-A-P. There are those disclosed in Japanese Patent Publication No. 8-151411 that directly react a specific lactone with a vinyl alcohol-based resin, but the present invention is not particularly limited.

The linear polysiloxane is represented by the following chemical formula (1), where n in the chemical formula (1) is an integer of 2 or more. R in the chemical formula (1) is preferably a lower alkyl group, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group and a branched alkyl group such as an iso-propyl group and a t-butyl group.

Since the linear polysiloxane has few pores in the molecular chain and the molecular chains can exist at a high density, it is considered that the path through which oxygen and water vapor can pass can be blocked and the gas barrier property is improved. In the present invention, if the linear structure of the linear polysiloxane is long, it is easy to form a network in the protective layer, so n is preferably 5 or more, more preferably 10 or more.

The linear polysiloxane can be obtained from an alkoxysilane represented by Si (OR) _4. R in the alkoxysilane is preferably a lower alkyl group, and examples thereof include a methyl group, an ethyl group, an n-propyl group and an n-butyl group. Specific examples of the alkoxysilane may be tetramethoxysilane (TMS, tetramethyl orthosilicate, hereinafter may be referred to as methyl silicate), tetraethoxysilane (TEOS, tetraethyl orthosilicate, hereinafter, ethyl silicate). ), Tetrapropoxysilane, tetrabutoxysilane, and these may be used alone or in admixture of two or more.

Alkoxysilanes are hydrolyzed in the presence of water, catalysts and organic solvents to give linear polysiloxanes. The water used for hydrolysis is preferably 0.8 equivalents or more and 5 equivalents or less with respect to the alkoxy group of Si (OR) 4. If the amount of water is less than 0.8 equivalent, hydrolysis may not proceed sufficiently and linear polysiloxane may not be obtained. If the amount of water is more than 5 equivalents, the reaction of alkoxysilane proceeds randomly, and a large amount of non-linear, random and sparse polysiloxane may be formed, and linear polysiloxane may not be obtained.

The catalyst used for hydrolysis is preferably an acid catalyst. Examples of the acid catalyst include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, tartaric acid and the like, and are not particularly limited. Normally, the hydrolysis and polycondensation reaction of alkoxysilane can proceed with either an acid catalyst or a base catalyst, but when an acid catalyst is used, the monomers in the system are hydrolyzed on average. It is easy and tends to be linear. On the other hand, when a base catalyst is used, the reaction mechanism is such that the hydrolysis and polycondensation reaction of the alkoxide bound to the same molecule easily proceeds, so that the reaction proceeds randomly and the reaction product tends to have many voids. The amount of the catalyst used is preferably 0.1 mol% or more and 0.5 mol% or less with respect to the total molar amount of alkoxysilane.

As the organic solvent used for hydrolysis, alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol and n-butyl alcohol which can be mixed with water and alkoxysilane can be used.

The hydrolysis temperature is preferably 20 ° C. or higher and 45 ° C. or lower. When the reaction is carried out at a temperature lower than 20 ° C., the reactivity is low and the hydrolysis of Si (OR) 4 may be difficult to proceed. On the other hand, when the reaction is carried out at a temperature exceeding 45 ° C., hydrolysis and polycondensation reaction may proceed rapidly, resulting in gelation or random and sparse polysiloxane that is not linear.

As the linear polysiloxane, a commercially available silicate oligomer raw material to which a plurality of Si (OR) 4 are bonded in advance can also be used. In the present invention, the protective layer may separately contain alkoxysilane (including a hydrolyzate of alkoxysilane) in addition to the vinyl alcohol resin and linear polysiloxane.

In the present invention, the protective layer is formed by using a coating solution consisting of an aqueous solution containing the vinyl alcohol resin, one or more organic silicon compounds having one or more alkoxy groups, and at least one of the hydrolysates thereof, or an alcohol mixed aqueous solution. To. With the above vinyl alcohol-based resin alone, the molecular chain is constrained by the hydrogen bonds between the hydroxyl groups in the molecular chain in the process of solidifying as a coating film, and excellent barrier performance against gases such as oxygen and nitrogen. However, barrier performance cannot be exhibited for water molecules because hydrogen bonds are plasticized. By preparing a resin composition composed of a vinyl alcohol-based resin and an organic silicon compound having an alkoxy group, an inorganic structure having a siloxane bond polycondensed between the organic silicon compounds as a skeleton and hydrogen at each hydroxyl group of the vinyl alcohol-based resin A so-called organic-inorganic hybrid structure having a covalent bond of Si—O— via oxygen appears in a bond and further a dehydration reaction. By limiting the bonding range between C-OH and Si-O-, the oxygen barrier performance can be maintained even if cracks occur in the inorganic compound layer. Furthermore, it binds to the polar groups on the surface of the inorganic compound layer to improve the adhesion, and further fills and reinforces defects such as pinholes, cracks, and grain boundaries of the inorganic compound layer to form a dense structure. And can demonstrate excellent gas barrier performance.

In the present invention, the ratio of the vinyl alcohol-based resin to the polysiloxane in the protective layer is the solid content mass of the vinyl alcohol-based resin which is an organic component in the protective layer, and the silicon atom contained in the total of the linear polysiloxane and the alkoxylan. It refers to the ratio of solid content mass converted from the total number of moles of Siloxane to _{2 weights of SiO.} The ratio of the vinyl alcohol-based resin fat to the polysiloxane is preferably 15/85 to 85/15, more preferably 35/65 to 20/80.

If the ratio of the vinyl alcohol-based resin to the linear polysiloxane exceeds 85/15, the ratio of the vinyl alcohol-based resin cannot immobilize the organic component, and the gas barrier property may decrease. On the other hand, if it is smaller than 15/85, the ratio of polysiloxane becomes high and the layer becomes hard, so that cracks may occur and the gas barrier property may decrease.

Further, the ratio of the solid content mass of the linear polysiloxane and the alkoxylan in the inorganic component in terms of the weight of each SiO2 is preferably in the range of linear polysiloxane / alkoxylan = 15/85 to 90/10. , 50/50 to 85/15 is more preferred, and 60/40 to 85/15 is even more preferred. When this value exceeds 90/10, the interaction between the linear polysiloxanes becomes strong, the organic component cannot be immobilized, and the gas barrier property may decrease. On the other hand, if it is less than 15/85, the number of Si—OH bonds derived from alkoxysilane may increase, the hydrophilicity may increase, and the gas barrier property may decrease.

In the present invention, the method for forming the protective layer is not particularly limited, and the protective layer can be formed by a method according to the base film. For example, if the coating liquid is coated using a roll coating method, a dip coating method, a bar coating method, a die coating method, a knife edge coating method, a gravure coating method, a kiss coating method, a spin coating method, or a combination of these methods. good.

The film thickness of the protective layer is preferably 0.1 to 0.6 μm, more preferably 0.3 to 0.5 μm. If the film thickness of the protective layer is less than 0.1 μm, the gas barrier performance cannot be sufficiently exhibited, and if the film thickness of the protective layer is 0.6 μm or more, the cohesive force of the protective layer is reduced and the cohesive force in the protective layer is reduced. Problems such as deterioration of gas barrier performance due to cohesive failure may occur.

By heat-treating the obtained protective layer, the condensation reaction proceeds and the protective layer tends to become denser. Specifically, the temperature conditions for the heat treatment are preferably 30 ° C. or higher and 100 ° C. or lower, and more preferably 40 ° C. or higher and 80 ° C. or lower. As the time condition of the heat treatment, 3 days or more and 7 days or less are preferable under the condition of 30 to 50 ° C., 3 days or more and 5 days or less are preferable at 50 to 80 ° C., and 2 days or more and 4 days at 80 to 100 ° C. The following is preferable. If the treatment does not meet the preferable heat treatment conditions under each temperature condition, the reaction in the protective layer becomes insufficient and the cohesive force decreases, so that the protective layer may be destroyed and peeled off. be. Further, when the heat treatment conditions under the respective temperature conditions are exceeded, the reaction in the protective layer proceeds too much, so that the cohesive force becomes high, the protective layer loses its flexibility, fracture occurs at the time of bending, and the oxygen permeability rate. May cause an increase in.

The oxygen permeability ratio (A / B) before and after bending of the oxygen permeability (B) before bending and the oxygen permeability (A) after bending of the transparent gas barrier film of the present invention is 1.0 to 2.0. If the oxygen permeability ratio before and after bending exceeds 2.0, the protective layer may be destroyed after bending and the oxygen permeability may decrease.

In the present invention, the water-wet adhesion strength is the adhesion strength measured under the measurement conditions described later while supplying pure water to the peeled portion of the laminated structure with a cotton swab, and is the water of the transparent gas barrier film of the present invention. Wet adhesion strength is 2N / 15 mm or more. It is preferably 3N / 15 mm or more. When the water-wet adhesion strength is less than 2N / 15 mm, it is a packaging material produced by punching, etc., and is stored in a container that bends after molding when the contents of the container are liquid or under high humidity. In addition, problems such as floating may occur between the layers in the packaging material. A method for producing the laminated body and a method for measuring the wett-adhesion strength will be described below. Polyester polyol (manufactured by Toyo Morton Co., Ltd., AD-503) as the main component of the adhesive is 50 parts by weight, while polyisocyanate (manufactured by Toyo Morton Co., Ltd., CAT-10) is 2.5 parts by weight as a curing agent, solvent. As a result, 50 parts by weight of ethyl acetate was mixed at room temperature with stirring, applied to the protective layer surface of the transparent gas barrier film using a bar coater, dried in a hot air oven, and then a low-density polyethylene film (thickness 40 μm, Mitsui Chemicals Tohcello). It was bonded with FC-S) manufactured by Co., Ltd. The laminated body thus bonded was stored in an oven at 40 ° C. for 72 hours to prepare a laminated body of a transparent gas barrier film and a low-density polyethylene film. This laminated structure is cut to a width of 15 mm, the low-density polyethylene at the start of peeling is held at 180 degrees to the transparent gas barrier film, and a tensile tester (“Tencilon” manufactured by A & D Co., Ltd.) is used. While maintaining the peeling angle at 180 degrees, pure water was supplied to the peeled portion with a cotton rod, and the water-wet adhesion strength was measured at a crosshead speed of 50 mm / min.

By setting the base film, the inorganic compound layer, and the protective layer in the above range, the oxygen permeability ratio (A / B) before and after bending of the oxygen permeability (B) before bending and the oxygen permeability (A) after bending is set. ) Is 1.0 to 2.0, and a transparent gas barrier film having a water-wet adhesion strength of 2N / 15 mm or more can be obtained. Further, 23 ° C., the oxygen permeability after flexing in 90% RH ^conditions, the following 0.2cc / m 2 · 24hr · atm .

In the present invention, "transparency" means that discoloration due to oxidation of the contents and contamination by foreign matter can be visually recognized through the transparent gas barrier film of the present invention, and when foreign matter is mixed with the bonding material, it is a defect detector in the bonding process. It means that it can be confirmed, and that the light transmittance at a wavelength of 400 to 700 nm is 80% or more of all light rays.

The transparent gas barrier film of the present invention is a laminated material in which a plastic film and a heat-sealing resin layer are provided on at least one side of the transparent gas barrier film, a plastic film on at least one side of the transparent gas barrier film, and the other side. Suitable as a laminated material provided with a heat-sealing resin layer, a laminated material provided with paper and a heat-sealing resin layer on at least one side of a transparent gas barrier film, and a heat-sealing resin layer on the other side. It can be used. It can also be used as a bag-shaped container or a paper container using the above-mentioned laminated material. These laminated materials, bag-shaped containers, and paper containers can be suitably used because the deterioration of oxygen permeability due to bending is small and the adhesion strength of water wetting is high.

A laminated material having a plastic film and a heat-sealing resin layer on at least one side of the transparent gas barrier film, or a plastic film on at least one side of the transparent gas barrier film and a heat-sealing resin layer on the other side. The provided laminated plastic film is not particularly limited as long as the characteristics such as mechanical strength, heat resistance, and light resistance are taken into consideration depending on the application, but typical examples thereof include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Polybutylene 2,6-naphthalate and other polyesters, polyvinyl alcohol, ethylene / vinyl acetate copolymer saponified products, polystyrene, polycarbonate, polyethylene, polypropylene and other polyolefins, 6 nylon, 12 nylon and other polyamides, aromatic polyamides, polyimides and the like. Examples thereof include films and sheets made of homopolymers or copolymers. Polyamide films and the like are preferably used from the viewpoint of maintaining strength against the contents and piercing resistance.

Examples of the container using this laminated material include a gusset-shaped bag and a standing pouch having a heat-sealing resin layer as an inner surface.

The laminated material provided with the paper and the heat-sealing resin layer on at least one side of the transparent gas barrier film of the present invention and the heat-sealing resin layer on the other side is the first heat-sealing with the paper base material layer. The sex resin layer, the transparent gas barrier film, and the second heat-sealing resin layer are provided in this order. Since the laminated material of the present invention has such a layer structure, it has excellent interlayer adhesion between the first heat-sealing resin layer, the transparent gas barrier film, and the second heat-sealing resin layer, and has excellent gas barrier properties. Therefore, it can be suitably used as a laminated material for various containers and the like.

The adhesive strength required between the transparent gas barrier film and the heat-sealing resin in the laminated material including paper is 1.5 N / 15 mm or more, preferably 2.0 N / 15 mm or more on the paper substrate side. On the content side, it is 3.0 N / 15 mm or more, preferably 3.5 N / 15 mm or more. With this adhesive strength, the transparent gas barrier film can be separated from the exterior material or resin layer by punching the laminated material into a blank plate or embossing with a ruled line for bending, or in-line from the rolled main laminated material. It is possible to reduce peeling in processes such as bending, embossing, and cutting in a box-making system.

The layer structure of the laminated material provided with the paper and the heat-sealing resin layer on at least one side of the transparent gas barrier film of the present invention and the heat-sealing resin layer on the other side will be described with reference to the drawings. The laminated material 5 containing paper shown in FIG. 1 includes a paper base material layer 1, a first heat-sealing resin layer 2, a transparent gas barrier film 3, and a second heat-sealing resin layer 4 in this order.

In a laminated material in which paper and a heat-sealing resin layer are provided on at least one side of the transparent gas barrier film of the present invention, and a heat-sealing resin layer is provided on the other side, the paper base material layer is arbitrary depending on the application. Paper substrate can be used. In particular, in order to make a box and use it as a liquid paper container, it is necessary to use a paper base material having sufficiently high moldability, bending resistance, rigidity, waist and strength. Such a paper base material is, for example, a strong-sized bleached or unbleached paper base material, or various paper base materials such as pure white roll paper, kraft paper, paperboard, and processed paper, and has a basis weight of about. 80~600g / ^{m 2} about ones can preferably be suitably used of about basis weight of about 100~450g / ^{m 2.}

As a method of laminating the paper base material layer on the first heat-sealing resin layer, the above-mentioned one or more kinds of thermoplastic resins may be extruded and laminated, or may be laminated via an adhesive or the like. May be dry laminated. As the heat-sealing resin layer, an ethylene-based polymer having a carboxyl group or an acid anhydride group in the molecule is preferably used. Examples of the ethylene-based polymer include a copolymer of ethylene and an unsaturated carboxylic acid or an anhydride thereof. The unsaturated carboxylic acid or its anhydride is a compound having at least one carbosyl group or an acid anhydride group in the molecule, and specifically, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and the like. Examples thereof include itaconic acid, anhydrous itaconic acid, fumaric acid, and crotonic acid. A copolymer of ethylene with acrylic acid or methacrylic acid is particularly preferably used in order to improve the adhesiveness of the inorganic oxide to the vapor-deposited film.

In the above ethylene-based copolymer, the ratio of ethylene to the unsaturated carboxylic acid or its anhydride, the melt flow rate (MFR), etc. are appropriately determined by those skilled in the art according to the properties of the paper substrate to be used and the like. can do. Usually, in order to enhance the adhesiveness between the heat-bondable resin layer and the transparent barrier film, it is preferable that the proportion of unsaturated carboxylic acid or its anhydride in the ethylene-based copolymer is high. In the present invention, the ratio of unsaturated carboxylic acid or its anhydride in the ethylene-based copolymer is about 3 to 9% by adhering the heat-bondable resin layer via the protective layer on the transparent barrier film. Sufficient adhesive strength can be achieved even at a low ratio. The thickness of the heat-bondable resin layer is preferably about 1 to 50 μm, more preferably about 3 to 20 μm, from the viewpoint of film forming property and adhesiveness.

The paper container of the present invention is made by manufacturing a laminated material using the above-mentioned paper, and can be particularly preferably used as a liquid paper container. The paper container may be any type such as a brick type, a flat type or a Goebel top type. Further, the shape can be any of a square container, a cylindrical paper can such as a round shape, and the like. The paper container of the present invention can be filled and packaged with various articles such as various foods and drinks, chemicals such as adhesives and adhesives, and miscellaneous goods such as cosmetics and pharmaceuticals. In particular, it is useful as a liquid paper container for filling and packaging juices such as liquor and fruit juice beverages, liquid seasonings such as mineral water, soy sauce, sauces and soups, and various liquid foods and drinks such as curry, stew and soups. be.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not necessarily limited thereto. The physical properties in Examples and Comparative Examples were measured as follows.

(1) Oxygen permeability ^{(cc / m 2 · 24hr ·} atm)
JIS K 7126-2 (2006) using a transparent gas barrier film or a laminated material for a paper container at a temperature of 23 ° C. and a humidity of 90% RH using an oxygen permeability meter (OXTRAN2 / 21) manufactured by MOCON in the United States. ), The oxygen permeability was measured.

(2) Thickness of protective layer The transparent gas barrier film is fixed in the embedding resin (BUEHLER, EPOXICURE2 HARDENER, EPOXICURE2 RESIN), and after the embedding resin containing the transparent gas barrier film is cured, it is used in a microtome (EMUC7 made by LEICA). It was cut in the cross-sectional direction of the transparent gas barrier film. The thickness of the protective layer of the transparent gas barrier film having the cross section thus produced was observed by SEM. For SEM, a scanning electron microscope S-3400N manufactured by Hitachi High-Tech Co., Ltd. was used, and three points were imaged at a magnification of 50,000 times. The thickness of the protective layer of the three obtained images was measured, and the average value was taken as the thickness of the protective layer.

(3) Oxygen permeability of transparent gas barrier film or laminated material after bending The transparent gas barrier film or laminated material for paper containers is cut into 15 cm squares, and the protective layer is on the upper surface so that diagonal lines can be drawn on the transparent gas barrier film. After folding the valley, sandwich it between aluminum plates (15 cm x 15 cm, thickness: 3 mm) and store it at room temperature for 5 minutes under a load of 200 g (see FIG. 2). Then, spread transparent gas barrier film, the diagonal of the center point, and set to come to the center of the chamber of the oxygen transmission rate system, the measuring method described above (1) Oxygen permeability ^{(cc / m 2 · 24hr ·} atm) The oxygen permeability was measured.

(4) Water-wet adhesion strength Polyester polyol (manufactured by Toyo Morton Co., Ltd., AD-503) as the main component of the adhesive is 50 parts by weight, while polyisocyanate (manufactured by Toyo Morton Co., Ltd., CAT-10) is used as the curing agent. 2.5 parts by weight and 50 parts by weight of ethyl acetate as a solvent are mixed while stirring at room temperature, applied to the protective layer surface of the transparent gas barrier film using a bar coater, dried in a hot air oven, and then a low density polyethylene film ( It had a thickness of 40 μm and was bonded to FC-S manufactured by Mitsui Kagaku Tohcello Co., Ltd. The laminated body thus bonded was stored in an oven at 40 ° C. for 72 hours to prepare a laminated body of a transparent gas barrier film and a low-density polyethylene film. This laminated structure is cut to a width of 15 mm, the low-density polyethylene at the start of peeling is held at 180 degrees to the transparent gas barrier film, and a tensile tester (“Tencilon” manufactured by A & D Co., Ltd.) is used. While maintaining the peeling angle at 180 degrees, while supplying pure water to the peeling point with a cotton swab, measure the crosshead speed at 50 mm / min and the peeling length of 50 mm, and average all the loads (N) within the measurement range. The value was set to the water-wet adhesion strength per 15 mm width.

(5) Transparency evaluation method Using an ultraviolet / visible / near-infrared spectrophotometer (UV-3600 manufactured by Shimadzu Corporation), the light transmittance at a wavelength of 400 to 700 nm for all light rays was measured. 80% or more was made transparent.

(6) Method for Measuring Film Thickness of Inorganic Compound Layer The film thickness of the inorganic compound layer was observed by cross-sectional TEM. First, a sample for cross-section observation was prepared by the FIB method using a microsampling system (FB-2000A manufactured by Hitachi High-Tech Co., Ltd.). Next, observation was performed using TEM (H-9000UHRII manufactured by Hitachi High-Tech Co., Ltd.) at an acceleration voltage of 300 kV so that the ratio of the layer thickness in the observation image to the obtained cross section was 30 to 70%. The observation magnification was adjusted, and the average value measured at three points was taken as the film thickness.

(Example 1)
<Method of forming the inorganic compound layer>
A biaxially stretched polyethylene terephthalate film (P60 manufactured by Toray Industries, Inc.) having a thickness of 12 μm was used as the base film, and after the base film was unwound in a vacuum chamber, the oxygen gas coefficient was 2.7 (cc · s). / (Min ・ m ² ))), oxygen gas is introduced into the ion generation source, and the anode power coefficient is 0.14 (kV) using a DC high-voltage power supply (SH type manufactured by Grassman High Voltage, Inc., USA). A · s / m ² ) After ion treatment, an aluminum oxide layer having a thickness of 10 nm was continuously provided by a vacuum vapor deposition method without winding to form an inorganic compound layer.

<Method of preparing vinyl alcohol-based resin solution>
As a vinyl alcohol-based resin, a modified polyvinyl alcohol having a γ-butyrolactone having a lactone structure as a cyclic structure having a carbonyl group (hereinafter abbreviated as modified PVA; polymerization degree 1,700, saponification degree 93.0%) is added by mass ratio. It was put into a solvent of water / isopropyl alcohol = 97/3 and heated and stirred at 90 ° C. to obtain an organic component solution having a solid content of 10% by mass.

<Method of preparing inorganic component solution>
A TEOS hydrolyzate was obtained by dropping 18.6 g of a 0.02N hydrochloric acid aqueous solution into a mixed solution of 11.7 g of TEOS (KBE-04 manufactured by Shin-Etsu Chemical Co., Ltd.) and 4.7 g of methanol with stirring. On the other hand, 7.0 g of 0.06N hydrochloric acid aqueous solution was added dropwise to a solution in which 11.2 g of ethyl silicate 40 (an average pentamer linear oligomer) manufactured by Corcote Co., Ltd. and 16.9 g of methanol were mixed as a linear polysiloxane. Then, a pentameric ethyl silicate hydrolyzate was obtained. The pentameric ethyl silicate hydrolyzed solution and the TEOS hydrolyzed solution were mixed so that the weight ratio of the solid content in terms _{of SiO 2 was 15/85 to obtain an inorganic component solution.}

<Method of manufacturing protective layer>
Mix and stir the PVA solution and the inorganic component solution so that the mass ratio of the PVA solid content and the SiO ₂ equivalent solid content (PVA solid content mass / SiO _{2 equivalent solid content mass) is 35/65, and water.} To obtain a coating solution having a solid content of 12% by mass. This coating liquid was applied onto the inorganic compound layer and dried at 120 ° C. to form a protective layer having a thickness of 0.4 μm to obtain a transparent gas barrier film. Then, it was heat-treated in a 40 ° C. oven for 3 days.

(Example 2)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 40/60 and the thickness of the protective layer was 0.3 μm.}

(Example 3)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 30/70 and the thickness of the protective layer was 0.5 μm.}

(Example 4)
A protective layer was formed in the same manner as in Example 1 except that the thickness of the protective layer was set to 0.5 μm, and heat-treated in a drying oven at 80 ° C. for 4 days to obtain a transparent gas barrier film.

(Example 5)
A transparent gas barrier film was obtained in the same manner as in Example 4 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 40/60 and the thickness of the protective layer was 0.4 μm.}

(Example 6)
A transparent gas barrier film was obtained in the same manner as in Example 4 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 30/70 and the thickness of the protective layer was 0.6 μm.}

(Example 7)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 20/80 and the thickness of the protective layer was 0.5 μm.}

(Example 8)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 15/85 and the thickness of the protective layer was 0.5 μm.}

(Example 9)
The protective layer was formed by the same method as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 65/35 and the thickness of the protective layer was 0.3 μm.} A transparent gas barrier film was obtained by heat-treating in an oven at 80 ° C. for 5 days.

(Example 10)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the inorganic compound layer was set to 5 nm.

(Example 11)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the inorganic compound layer was set to 20 nm.

(Example 12)
A transparent gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the protective layer was set to 0.1 μm.

(Example 13)
Using the transparent gas barrier film of Example 3, 50 parts by weight of polyester polyol (manufactured by Toyo Morton Co., Ltd., AD-503) as the main agent of the adhesive and polyisocyanate (manufactured by Toyo Morton Co., Ltd.) as a curing agent. CAT-10) 2.5 parts by weight and 50 parts by weight of ethyl acetate as a solvent are mixed while stirring at room temperature, applied to the protective layer of the transparent gas barrier film using a bar coater, dried in a hot air oven, and then nylon. It was bonded to a film (thickness 15 μm ONU manufactured by Unitika Ltd.). After that, an adhesive was applied to the side of the nylon film on which the transparent gas barrier film was not bonded by the same method as described above, and a polyolefin film (thickness 60 μm, ZK207 manufactured by Toray Film Processing Co., Ltd.) was bonded. Was stored in an oven at 40 ° C. for 72 hours to prepare a laminated material containing a plastic film.

(Example 14)
Using the transparent gas barrier film of Example 4, the same adhesive as in Example 13 was applied to the protective layer surface of the transparent gas barrier film using a bar coater, dried in a hot air oven, and then the same nylon film as in Example 13. I pasted them together. Then, an adhesive was applied to the base film side of the transparent gas barrier film by the same method as described above to prepare a laminated body in which the same polyolefin film as in Example 13 was bonded, and stored in an oven at 40 ° C. for 72 hours to make a plastic. A laminated material containing a film was produced.

(Example 15)
Using the transparent gas barrier film of Example 1, one surface of a paper substrate (manufactured by Potlatch, USA, basis weight 400 g / m ² ) is subjected to corona treatment, and then the corona discharge treated surface is subjected to corona treatment. , Low-density polyethylene resin (manufactured by Mitsui Petrochemical Co., Ltd., trade name, M16P) melt-extruded at an extrusion temperature: 300 ° C., extrusion film thickness: 15 μm), a first heat-sealing resin layer surface, and a transparent gas barrier film. Second heat-sealing resin layer surface (manufactured by Mitsui Petrochemical Co., Ltd., trade name, M16P, extrusion temperature: A laminated material containing paper was obtained by forming an extrusion film thickness (15 μm) at 300 ° C.

(Example 16)
Using the laminated material obtained in Example 13, a bag-shaped container in the form of a 200 ml gusset bag was prepared.

(Example 17)
Using the laminated material obtained in Example 14, a 200 ml standing pouch-shaped bag-shaped container was prepared.

(Example 18)
Using the laminated material obtained in Example 15, a 200 ml paper container was prepared.

(Comparative Example 1)
A protective layer was formed by the same method as in Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 50/50, and a transparent gas barrier film was obtained without heat treatment.} rice field.

(Comparative Example 2)
A transparent gas barrier film was obtained in the same manner as in Comparative Example 1 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 20/80.}

(Comparative Example 3)
A protective layer was formed in the same manner as in Comparative Example 1 and heat-treated in a drying oven at 40 ° C. for 3 days to obtain a transparent gas barrier film.

(Comparative Example 4)
A protective layer was formed in the same manner as in Example 1 and heat-treated in an oven at 80 ° C. for 7 days to obtain a transparent gas barrier film.

(Comparative Example 5)
A protective layer was formed in the same manner as in Comparative Example 2, and heat-treated in an oven at 80 ° C. for 7 days to obtain a transparent gas barrier film.

(Comparative Example 6)
A protective layer was formed in the same manner as in Example 5 and heat-treated in an oven at 80 ° C. for 7 days to obtain a transparent gas barrier film.

(Comparative Example 7)
The same as in Example 1 except that the thickness of the inorganic compound layer is 3 nm, _{the mass ratio of the solid content of PVA to the solid content converted to SiO 2} is 50/50, and the thickness of the protective layer is 0.05 μm. A transparent gas barrier film was obtained by the method.

(Comparative Example 8)
The same as in Example 1 except that the thickness of the inorganic compound layer is 25 nm, _{the mass ratio of the solid content of PVA to the solid content converted to SiO 2} is 50/50, and the thickness of the protective layer is 1.1 μm. A transparent gas barrier film was obtained by the method.

(Comparative Example 9)
A transparent gas barrier film was obtained in the same manner as in Comparative Example 3 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was set to 10/90.}

(Comparative Example 10)
A transparent gas barrier film was obtained in the same manner as in Comparative Example 3 except that the mass ratio of the solid content of PVA to the solid content _{converted to SiO 2 was 90/10.}

(Comparative Example 11)
Using the transparent gas barrier film of Comparative Example 6 as the transparent gas barrier film, a laminated material containing a plastic film was prepared by the same method as in Example 13.

(Comparative Example 12)
Using the transparent gas barrier film of Comparative Example 7, a laminated material containing a plastic film was prepared in the same manner as in Example 13.

(Comparative Example 13)
Using the transparent gas barrier film of Comparative Example 1, a laminated material containing paper was prepared in the same manner as in Example 15.

(Comparative Example 14)
Using the laminated material obtained in Comparative Example 11, a bag-shaped container in the form of a 200 ml gusset bag was prepared.

(Comparative Example 15)
Using the laminated material containing the plastic film obtained in Comparative Example 12, a 200 ml standing pouch-shaped bag-shaped container was prepared.

(Comparative Example 16)
A 200 ml paper container was prepared using the laminated material containing the plastic film obtained in Comparative Example 13.

The transparent gas barrier film of the above examples and comparative examples, the laminated material including paper, the film thickness of the inorganic oxide of each laminated material, the film thickness of the protective layer, the oxygen permeability before and after bending, the water-wet adhesion strength, and the bag-shaped container. , The oxygen permeability of the paper container and the water-wet adhesion strength were measured, respectively. The results are shown in Table 1-1 and Table 1-2.

1: Paper substrate layer 2: First heat-sealing resin layer 3: Transparent gas barrier film 4: Second heat-sealing resin layer 5: Laminated material containing paper 6: Base film 7: Inorganic compound layer 8: Protective layer

Claims (10)

A laminate having an inorganic compound layer and a protective layer in this order from the base film side on at least one side of the base film, and the protective layer contains a cyclic compound structure having a carbonyl group in the cyclic structure. It contains a vinyl alcohol-based resin and a linear polysiloxane, and the ratio of the solid content mass of the vinyl alcohol-based resin and the linear polysiloxane is 15/85 to 85/15, and the oxygen permeability (B) before bending is used. A transparent gas barrier film having an oxygen permeation rate (A) after bending, an oxygen permeation rate ratio (A / B) before and after bending of 1.0 to 2.0, and a water-wet adhesion strength of 2N / 15 mm or more. The transparent gas barrier film according to claim 1, wherein the vinyl alcohol-based resin is a vinyl alcohol-based resin having a lactone structure. The transparent gas barrier film according to claim 1 or 2, wherein the protective layer is an organic-inorganic mixture layer and the thickness of the protective layer is 0.1 to 0.6 μm. The transparent gas barrier film according to any one of claims 1 to 3, wherein the inorganic compound layer is an aluminum oxide layer or a layer made of aluminum oxide and has a film thickness of 5 to 20 nm. Oxygen transmission rate at 23 ° C. 90% RH conditions after ^bending, a transparent gas barrier film according to claim 1 or less 0.2cc / m 2 · 24hr · atm . A laminated material in which a plastic film and a heat-sealing resin layer are provided on at least one side of the transparent gas barrier film according to any one of claims 1 to 5. A laminated material in which a plastic film is provided on at least one side of the transparent gas barrier film according to any one of claims 1 to 5, and a heat-sealing resin layer is provided on the other side. A laminated material in which paper and a heat-sealing resin layer are provided on at least one side of the transparent gas barrier film according to any one of claims 1 to 5, and a heat-sealing resin layer is provided on the other side. A bag-shaped container using the laminated material according to any one of claims 6 to 7. A paper container using the laminated material of claim 8.

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