JP7331444B2 - barrier film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a barrier film, and more particularly to a barrier film comprising a substrate layer, a first physical vapor deposition layer, a barrier coat layer, and a second physical vapor deposition layer in this order.

In recent years, inorganic oxides such as silicon oxide and aluminum oxide have been formed on film substrates by vacuum deposition, sputtering, ion plating, chemical vapor deposition, etc., as barrier materials against oxygen, water vapor, and the like. A transparent gas barrier film is attracting attention. In particular, depending on the application of the barrier film, it has been necessary to maintain a high level of gas barrier properties. In order to solve such a technical problem, for example, a substrate made of a plastic material, a first evaporated thin film layer formed of an inorganic material and provided in contact with the substrate, and the first evaporated thin film layer and a gas barrier intermediate layer formed by applying a coating agent containing at least a water-soluble polymer, and a second vapor-deposited thin film layer formed of an inorganic material and directly vapor-deposited on the intermediate layer. A laminate having such a structure has been proposed (see Patent Document 1).

Moreover, depending on the use of the barrier film, light shielding properties are required in addition to the gas barrier properties. In order to solve such a technical problem, for example, Japanese Laid-Open Patent Publication No. 2002-100001 proposes a laminate in which metal aluminum is vapor-deposited as a second vapor-deposited thin film layer. In addition, a metal tone printed layer, an adhesive layer, and a light-shielding sealant layer on the surface of the gas barrier coating layer of a transparent gas barrier film obtained by laminating an inorganic oxide thin film layer and a gas barrier coating layer on at least one surface of a transparent substrate layer. wherein the metallic printed layer is made of an ink film mixed with an anti-blocking agent consisting of surface-treated aluminum metal powder and inorganic powder for improving adhesion to the binder resin. A light-shielding barrier packaging material characterized by is proposed (see Patent Document 2).

Japanese Patent No. 4085814 JP-A-2005-1753

In recent years, depending on the use of barrier films, water resistance, especially water-resistant adhesion, has been required in addition to gas barrier properties. The present inventors have found the biaxially stretched polyethylene terephthalate film/aluminum oxide vapor deposition layer (first vapor deposition thin film layer)/gas barrier intermediate layer/metal aluminum vapor deposition layer (second vapor deposition thin film layer) described in Patent Document 1. A new technical problem was discovered in that a laminate having a layered structure is inferior in water-resistant adhesion. In addition, in the light-shielding barrier packaging material described in Patent Document 2, it is necessary to add an inorganic powder to the metal-tone printed layer, or add a light-shielding agent such as carbon black to the light-shielding sealant layer. There are problems such as adhesion between layers and cost.

The present invention has been made in view of the above background art and new technical problems, and an object of the present invention is to provide a barrier film that is excellent in gas barrier properties, light shielding properties, and water-resistant adhesion.

The inventors of the present invention have made intensive studies to solve the above problems, and found that the substrate layer, the first physical vapor deposition layer, the barrier coat layer, and the second physical vapor deposition layer are formed in this order. In the barrier film provided, an oxygen plasma-treated surface is formed by subjecting a base layer to oxygen plasma treatment, and an aluminum oxide vapor-deposited film is formed as a first physical vapor deposition layer on the oxygen plasma-treated surface to provide a gas barrier. The present inventors have found that a barrier film having excellent properties, light-shielding properties, and water-resistant adhesion can be provided. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
A barrier film comprising a substrate layer, a first physical vapor deposition layer, a barrier coat layer, and a second physical vapor deposition layer in this order,
An oxygen plasma-treated surface is formed by subjecting the base material layer to oxygen plasma treatment,
forming the first physical vapor deposition layer on the oxygen plasma-treated surface;
A barrier film is provided, wherein the first physical vapor deposition layer is an aluminum oxide deposition film.

In the aspect of this invention, it is preferable that said 2nd physical vapor deposition layer is an aluminum vapor deposition film.

In the aspect of this invention, it is preferable that the said base film is a biaxially stretched polyethylene terephthalate film.

In the aspect of the present invention, the barrier coat layer is preferably a cured resin film of metal alkoxide and water-soluble polymer.

In the aspect of the present invention, the barrier coat layer is preferably a cured resin film containing a reaction product obtained by reacting a metal oxide and a phosphorus compound.

In the aspect of the present invention, the barrier coat layer is preferably a cured resin film containing a carboxyl group-containing polymer crosslinked with a polyvalent metal compound.

In an embodiment of the present invention, the barrier film has an acidity permeability of 1.0 cc/m ² ·atm·day or less measured in accordance with JIS K7126 in an environment of temperature 23° C. and humidity 90% RH. Preferably.

In an aspect of the present invention, the barrier film has a water vapor transmission rate of 1.0 g/m ² ·day or less measured in accordance with JIS K7129 under an environment of temperature 40° C. and humidity 100% RH. is preferred.

In an aspect of the present invention, the barrier film preferably has a total light transmittance of 10% or less as measured according to JIS K7361.

Another aspect of the present invention provides a moisture-proof sheet comprising the above barrier film.

In another aspect of the invention, a thermal insulator is provided comprising the barrier film described above.

In another aspect of the invention, a packaging material is provided comprising the barrier film described above.

ADVANTAGE OF THE INVENTION According to this invention, the barrier film which is excellent in gas-barrier property, light-shielding property, and water-resistant adhesiveness can be provided. Such a barrier film can be suitably used for applications requiring high gas barrier properties, moisture resistance, light shielding properties, etc., such as moisture barrier sheets, heat insulating materials, packaging materials, and the like.

1 is a schematic cross-sectional view showing one embodiment of a barrier film of the present invention; FIG.

<Barrier film>
A barrier film according to the present invention comprises a substrate layer, a first physical vapor deposition layer, a barrier coat layer, and a second physical vapor deposition layer in this order.

The barrier film preferably has an acidity permeability of 1.00 cc/m ² atm day or less, more preferably 0, measured according to JIS K7126 in an environment of temperature 23° C. and humidity 90% RH. 0.50 cc/m ² ·atm·day or less, more preferably 0.20 cc/m ² ·atm·day or less, still more preferably 0.10 cc/m ² ·atm·day or less. If the oxygen permeability is within the above numerical range, it has suitable oxygen barrier properties and can be used in various applications that require oxygen barrier properties. The oxygen permeability can be measured using an oxygen permeability meter (OX-TRAN manufactured by MOCON).

The barrier film preferably has a water vapor transmission rate of 1.00 g/m ² ·day or less, more preferably 0.50 g, measured in accordance with JIS K7129 under an environment of temperature 40°C and humidity 100% RH. /m ² ·day or less, more preferably 0.20 g/m ² ·day or less, still more preferably 0.10 g/m ² ·day or less.
If the water vapor transmission rate is within the above numerical range, it has suitable water vapor barrier properties and can be used in various applications requiring water vapor barrier properties. The water vapor transmission rate can be measured using a water vapor transmission rate measuring machine (manufactured by MOCON: PERMATRAN).

The barrier film has a total light transmittance measured according to JIS K7361 of preferably 10% or less, more preferably 8% or less, and still more preferably 6% or less. If the total light transmittance is within the above numerical range, it has suitable light-shielding properties, and can be used in various applications that require light-shielding properties. The total light transmittance can be measured using a haze meter (HM-150, manufactured by Murakami Lighting Laboratory Co., Ltd.).

The layer structure of the barrier film will be described with reference to the drawings. The barrier film 10 shown in FIG. 1 includes a substrate layer 11, a first physical vapor deposition layer 12, a barrier coat layer 13, and a second physical vapor deposition layer 14 in this order. Each layer constituting the barrier film of the present invention will be described below.

(Base material layer)
The substrate layer used in the barrier film of the present invention is not particularly limited. Any resin film that can be held well without damage can be used. Specifically, for example, polyolefin resins such as polyethylene resins or polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), poly(meth)acrylic resins, polycarbonate resins, polyvinyl alcohol resins, saponified ethylene-vinyl ester copolymers, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, and polyamide resins such as various nylons. , polyurethane-based resins, acetal-based resins, and cellulose-based resins. In the present invention, among the above resin films, it is particularly preferable to use films of polyester resin, polyolefin resin, or polyamide resin. The substrate layer may be an unstretched film of the above resin, a uniaxially or biaxially stretched resin film, or the like.

As the polyester-based resin film, the following polyester films can be used in addition to general petroleum-derived polyethylene terephthalate.

(Polybutylene terephthalate film (PBT))
Polybutylene terephthalate film has a high heat distortion temperature, excellent mechanical strength and electrical properties, and good molding processability. It is possible to suppress the deformation of the packaging bag and the reduction in its strength. A polybutylene terephthalate film is a film containing polybutylene terephthalate (hereinafter also referred to as PBT) as a main component, preferably a resin film containing 60% by mass or more of PBT.

(polyester film derived from biomass)
The biomass-derived polyester film is composed of a resin composition containing a polyester composed of a diol unit and a dicarboxylic acid unit as a main component, and the resin composition is such that the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit. is a fossil fuel-derived dicarboxylic acid in an amount of 50 to 95% by mass, preferably 50 to 90% by mass, based on the total resin composition.

Biomass-derived ethylene glycol is produced from biomass such as sugar cane and corn (biomass ethanol) as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

The dicarboxylic acid units of the polyester use dicarboxylic acids derived from fossil fuels. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid, and examples of derivatives of aromatic dicarboxylic acids include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters and butyl esters. Ester etc. are mentioned. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the aromatic dicarboxylic acid derivative.

The polyester that may be contained at a rate of 5 to 45% by mass in the resin composition that forms the biomass-derived polyester film is a fossil fuel-derived polyester, a recycled polyester of a fossil fuel-derived polyester product, or a biomass-derived polyester product. of recycled polyester.

(recycled polyethylene terephthalate)
A polyethylene terephthalate film containing polyethylene terephthalate recycled by mechanical recycling, specifically containing PET obtained by mechanically recycling PET bottles, in which the diol component is ethylene glycol and the dicarboxylic acid component is terephthalic acid. and isophthalic acid. The content of the isophthalic acid component is preferably 0.5 mol % or more and 5 mol % or less, and 1.0 mol % or more and 2.5 mol % or less, in the total dicarboxylic acid component constituting the PET. is more preferred.

Here, mechanical recycling generally refers to the process of pulverizing collected PET bottles and other polyethylene terephthalate resin products, washing with alkali to remove dirt and foreign matter from the surface of the PET resin products, and then drying for a certain period of time under high temperature and reduced pressure. This method decontaminates the PET resin by diffusing the contaminants remaining inside the PET resin, removes dirt from the resin product made of the PET resin, and returns it to the PET resin.

Recycled polyethylene terephthalate preferably contains recycled PET at a ratio of 50% by weight or more and 95% by weight or less, and may contain virgin PET. For virgin PET, a common diol component is ethylene glycol and the dicarboxylic acid component is terephthalic acid, and may also include isophthalic acid.

The film thickness of various resin films is preferably about 6 to 2000 μm, more preferably about 9 to 100 μm.

(surface treatment)
In the present invention, before forming the first physical vapor deposition layer on the substrate layer, the substrate layer is previously surface-treated with oxygen plasma. This can improve adhesion with the first physical vapor deposition layer. As the surface treatment with oxygen plasma, for example, by performing oxygen plasma treatment in-line, moisture, dust, etc. on the surface of the base material layer can be removed, and surface treatment such as smoothing and activation of the surface can be performed. be able to. In the present invention, plasma discharge treatment is preferably performed in consideration of plasma output, type of plasma gas, supply amount of plasma gas, treatment time, and other conditions. As a method for generating plasma, devices such as DC glow discharge, high frequency discharge, and microwave discharge can be used. Plasma treatment can also be performed by an atmospheric pressure plasma treatment method.

In the surface treatment of the substrate layer, ethylene gas or argon gas may be used together as plasma gas. By using ethylene gas together, a diamond-like carbon-like film is formed on the treated surface, and gas barrier properties and water-resistant adhesion can be further improved.

(First physical vapor deposition layer)
The first physical vapor deposition layer constituting the barrier film according to the present invention is a vapor deposition film formed by a physical vapor deposition method (PVD method). In the present invention, by forming an aluminum oxide deposition film as the first physical vapor deposition layer, it is possible to improve the light shielding property while improving the gas barrier property.

Examples of the physical vapor deposition method (PVD method) include a vacuum deposition method, a sputtering method, an ion plating method, an ion cluster beam method, and the like. Specifically, for example, aluminum oxide is used as a raw material, which is heated and vaporized, and is vaporized on the oxygen plasma-treated surface of the substrate layer (resin film) using a vacuum vapor deposition method or the like to form an aluminum oxide deposited film. can be formed. In addition, as a method of heating the vapor deposition material, for example, a resistance heating method, a high frequency induction heating method, an electron beam heating method (EB), or the like can be used.

The thickness of the deposited aluminum oxide film is preferably 20 nm or more and 500 nm or less, more preferably 30 nm or more and 500 nm or less, and still more preferably 40 nm or more and 500 nm or less. If the film thickness of the vapor-deposited aluminum film is within the above range, it is possible to further improve the light shielding property while exhibiting sufficient gas barrier property.

(Barrier coat layer)
The barrier coat layer formed on the chemical vapor deposition layer is a layer having gas barrier properties, and the coating film applied by coating is a cured resin film cured by drying.

As a first aspect of the barrier coat layer, a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer can be used. This barrier coat layer can be formed of, for example, the following gas barrier coating film. The gas barrier coating film is a coating film that maintains gas barrier properties in a hot and humid environment, and the gas barrier coating film is a coating film that maintains gas barrier properties in a hot and humid environment, and has the general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) and at least one metal alkoxide represented by and a water-soluble polymer; and a coating film made of a barrier coating composition obtained by polycondensation by a sol-gel method in the presence of an organic solvent.

In the general formula R ¹ _n M(OR ² ) _m , R ¹ is an optionally branched alkyl group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms. , for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group, etc. can be mentioned.

In the general formula R ¹ _n M(OR ² ) _m , R ² is an optionally branched alkyl group having 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, particularly preferably 1 to 4 carbon atoms. Examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group and the like. When multiple (OR ² ) are present in the same molecule, the (OR ² ) may be the same or different.

Examples of metal atoms represented by M in the general formula R ¹ _n M(OR ² ) _m include silicon, zirconium, titanium, and aluminum.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , at least one kind of partial hydrolyzate of alkoxide and hydrolytic condensate of alkoxide can be used. The partial hydrolyzate is not limited to those in which all of the alkoxy groups are hydrolyzed, and may be those in which one or more of the alkoxy groups are hydrolyzed, or mixtures thereof, and condensates of hydrolysis. As the partially hydrolyzed alkoxide, a dimer or higher, specifically a dimer to a hexamer may be used.

In the present invention, alkoxysilanes in which M is Si can be preferably used as the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m . Suitable alkoxysilanes include, for example, tetramethoxysilane Si( _OCH3 ) ₄ , tetraethoxysilane Si( _OC2H5 ) _{4 , tetrapropoxysilane} Si( _OC3H7 ) ₄ , tetrabutoxysilane Si( _OC4 H ₉ ) ₄ , methyltrimethoxysilane CH ₃ Si(OCH ₃ ) ₃ , methyltriethoxysilane CH ₃ Si(OC ₂ H ₅ ) ₃ , dimethyldimethoxysilane (CH ₃ ) ₂ Si(OCH ₃ ) 2 , dimethyldimethoxysilane (CH 3 ) 2 Si(OCH 3 ) ₂ ethoxysilane (CH ₃ ) ₂ Si(OC ₂ H ₅ ) ₂ and the like. Condensation products of these alkoxysilanes can also be used in the present invention. Specifically, for example, polytetramethoxysilane, polytetraemethoxysilane, and the like can be used.

In the present invention, a zirconium alkoxide in which M is Zr can also be suitably used as the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m . Suitable zirconium alkoxides include, for example, tetramethoxyzirconium Zr _{( OCH3} ) ₄ , tetraethoxyzirconium Zr( _OC2H5 ) ₄ , _tetra -i-propoxyzirconium Zr(iso- _OC3H7 ) ₄ , tetra-n-butoxyzirconium Zr( _OC4H9 ) ₄ etc. can be illustrated _.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , titanium alkoxide in which M is Ti can also be suitably used. Suitable titanium alkoxides include, _for example, tetramethoxytitanium Ti( _OCH3 ) ₄ , tetraethoxytitanium Ti( _OC2H5 ) ₄ , tetraisopropoxytitanium Ti(iso- _{OC3H7 ) 4} , tetra-nbutoxytitanium Ti( _OC4H9 ) ₄ etc. can be illustrated _.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , an aluminum alkoxide in which M is Al can also be preferably used. Suitable aluminum alkoxides include, for example, tetramethoxyaluminum Al(OCH ₃ ) ₄ , tetraethoxyaluminum Al(OC ₂ H ₅ ) ₄ , tetraisopropoxyaluminum Al(iso-OC ₃ H ₇ ) ₄ , tetra-n-butoxyaluminum Al( _OC4H9 ) ₄ etc. can be illustrated _.

In the present invention, the above alkoxides may be used in combination of two or more. For example, when alkoxysilane and zirconium alkoxide are mixed and used, the toughness, heat resistance, etc. of the resulting barrier film can be improved. Further, when alkoxysilane and titanium alkoxide are mixed and used, the thermal conductivity of the resulting gas barrier coating film is lowered, and the heat resistance is remarkably improved.

The water-soluble polymer used in the present invention may be a polyvinyl alcohol resin or an ethylene/vinyl alcohol copolymer alone, or may be a polyvinyl alcohol resin and an ethylene/vinyl alcohol copolymer. Combines can be used in combination. In the present invention, physical properties such as gas barrier properties, water resistance, weather resistance, etc. can be remarkably improved by using a polyvinyl alcohol resin and/or an ethylene-vinyl alcohol copolymer.

As polyvinyl alcohol-based resins, those obtained by saponifying polyvinyl acetate can generally be used. The polyvinyl alcohol resin may be a partially saponified polyvinyl alcohol resin in which several tens of percent of acetic acid groups remain, a fully saponified polyvinyl alcohol in which no acetic acid groups remain, or a modified polyvinyl alcohol resin in which OH groups have been modified. Well, not particularly limited.

As the ethylene/vinyl alcohol copolymer, a saponified copolymer of ethylene and vinyl acetate, that is, a product obtained by saponifying an ethylene-vinyl acetate random copolymer can be used. Examples include partially saponified products in which several tens of mol % of acetic acid groups remain, to complete saponified products in which only several mol % of acetic acid groups or no acetic acid groups remain, and are not particularly limited. However, from the viewpoint of gas barrier properties, it is preferable to use one having a degree of saponification of 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more. The content of repeating units derived from ethylene in the ethylene/vinyl alcohol copolymer (hereinafter also referred to as "ethylene content") is usually 0 to 50 mol%, preferably 20 to 45 mol%. is preferred.

A silane coupling agent may also be added to the barrier coat layer. For example, silane coupling agents having reactive groups such as alkoxy groups such as methoxy groups and ethoxy groups, acetoxy groups, amino groups and epoxy groups can be used. Specifically, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxy Propylmethyldiethoxysilane, γ-glycidoxypropyldimethylethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or the like can be used.

Furthermore, as the organic solvent used in the above barrier coating composition, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol and the like can be used. The polyvinyl alcohol-based resin and/or the ethylene/vinyl alcohol copolymer is preferably handled in a dissolved state in a coating solution containing the alkoxide, silane coupling agent, etc., and is selected from the above organic solvents. It can be selected as appropriate. For example, when a polyvinyl alcohol resin and an ethylene-vinyl alcohol copolymer are used in combination, it is preferable to use n-butanol.

A barrier coat layer can be manufactured by the following method. First, the above metal alkoxide and, if necessary, a silane coupling agent, a water-soluble polymer, a sol-gel process catalyst, an acid, water, an organic solvent, etc. are mixed to prepare a barrier coating composition (barrier coating liquid).

The barrier coat composition is then applied over the chemical vapor deposition layer. The method of applying the barrier coating composition includes, for example, coating means such as roll coating such as gravure roll coater, spray coating, spin coating, dipping, brush, bar code, and applicator, and can be applied once or multiple times. A coating film having a dry film thickness of 0.01 to 30 μm, preferably 0.1 to 10 μm can be formed.

Next, the film coated with the above barrier coating composition is heated to 120°C to 200°C and at a temperature not higher than the melting point of the resin film of the base film of the barrier film, preferably 130°C to 180°C, more preferably 140°C to 160°C. Heat and dry at a temperature in the range of 3 seconds to 10 minutes. By this, polycondensation is performed and a barrier coat layer can be formed. In addition, the barrier coating composition is coated on the chemical vapor deposition layer to form two or more layers of the coating film, and the temperature is 120° C. to 200° C. and the melting point of the resin base material or less for 3 seconds. A composite polymer layer having two or more barrier coat layers may be formed by heating and drying for up to 10 minutes. As described above, one to two or more barrier coat layers can be formed from the above barrier coat composition.

The thickness of the barrier coat layer is not particularly limited, but is preferably 10 nm or more and 5000 nm or less, more preferably 50 nm or more and 1000 nm or less, still more preferably 100 nm or more and 500 nm or less, and even more preferably 150 nm or more and 400 nm or less. is. If the thickness of the barrier coat layer is within the above range, the surface of the chemical vapor deposition layer can be coated with a flexible layer that exhibits gas barrier properties.

As a second aspect of the barrier coat layer, a cured resin film containing a reaction product obtained by reacting a metal oxide and a phosphorus compound can be used. This cured resin film has a gas barrier property and has a wave number in the range of 1080 to 1130 cm -1 at which the maximum infrared absorption in the infrared absorption spectrum in the range of 800 to 1400 cm -1 is present.

In the reaction product, when a bond represented by M—O—P is formed in which a metal atom (M) and a phosphorus atom (P) constituting the metal oxide are bonded via an oxygen atom (O), M It is considered that the absorption peak due to the --OP bond appears as the absorption peak of the maximum absorption wave number in the region of 800 to 1400 cm -1 in the range of 1080 to 1130 cm -1 .

This infrared absorption spectrum can be obtained by measuring the surface of the barrier coat layer by the total reflection measurement method or by measuring the infrared absorption spectrum of the components scraped off the barrier coat layer by the KBr method.

Metal oxides are oxides of magnesium, calcium, aluminum, silicon, titanium, zirconium, and the like.

The metal oxide can be obtained by hydrolyzing a compound containing the metal atom, and examples of the compound that can produce the metal oxide by hydrolysis include aluminum chloride, aluminum triethoxide, and aluminum tri-normal propoxide, aluminum triisopropoxide, aluminum tri-butoxide, aluminum tri-s-butoxide, aluminum tri-t-butoxide, aluminum triacetate, aluminum acetylacetonate, aluminum nitrate, titanium tetraisopropoxide, titanium tetra-butoxide, titanium tetra (2-ethylhexoxide), titanium tetramethoxide, titanium tetraethoxide, titanium acetylacetonate, zirconium tetra-normal propoxide, zirconium tetrabutoxide, zirconium tetraacetylacetonate, etc., may be used alone. Alternatively, two or more types may be used in combination.

A phosphorus compound having a structure in which a halogen atom or an oxygen atom is directly bonded to a phosphorus atom can be used. Specifically, phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. Examples of polyphosphoric acid include pyrophosphoric acid, triphosphoric acid, and polyphosphoric acid in which four or more phosphoric acids are condensed. Examples of derivatives include salts, (partial) ester compounds, halides (chlorides, etc.), dehydrates (diline pentoxide, etc.) of phosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid.

The reaction product can be formed by mixing and reacting the metal oxide and the phosphorus compound. At that time, the phosphorus compound to be mixed may be in the form of itself or in the form of a composition containing the phosphorus compound and the additive resin.

Such additive resins include polyvinyl alcohol, partially saponified polyvinyl acetate, polyethylene glycol, polyhydroxyethyl (meth)acrylate, polyacrylic acid, polymethacrylic acid, poly(acrylic acid/methacrylic acid) and salts thereof, Ethylene-vinyl alcohol copolymer, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride alternating copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer Examples include saponified polymers.

In the present invention, the barrier coat layer can be laminated by coating the chemical vapor deposition layer with a coating liquid in which a metal oxide and a phosphorus compound are mixed, and drying the coating liquid, and the thickness thereof is 0.05. ~1 μm.

In addition, the coating liquid is first prepared by dispersing and dissolving a compound that can be generated by hydrolysis of a metal oxide to form an aqueous solution in which a metal oxide is generated. It can be produced by adding a composition containing an additive resin to a solvent in which it is dispersed and dissolved.

As a third aspect of the barrier coat layer, a cured resin film containing a carboxyl group-containing polymer crosslinked with a polyvalent metal compound can be used. This cured resin film has gas barrier properties.

The carboxyl group-containing polymer is a polymer containing two or more carboxyl groups, specifically polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, or two of these. It is a mixture of the above.

Polyvalent metal compounds are metal compounds of beryllium, magnesium, calcium, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, oxides, carbonates and organic acid salts thereof. These oxides and carbonates include oxides such as zinc oxide, magnesium oxide, copper oxide, nickel oxide and cobalt oxide; carbonates such as calcium carbonate; organic acid salts such as calcium lactate, zinc lactate and calcium acrylate. be. A resin film containing a carboxyl group-containing polymer crosslinked by a polyvalent metal compound can be produced as a cured resin film by mixing a carboxyl group-containing polymer and a polyvalent metal compound.

Another form of this resin film can be produced by forming a two-layer structure in which a layer containing a polyvalent metal compound is laminated adjacent to a resin layer containing a carboxyl group-containing polymer. The resin layer containing the carboxyl group-containing polymer is ionically crosslinked by the polyvalent metal ions migrated from the layer containing the polyvalent metal compound which is in contact with the resin layer to form a cured resin film.

The resin layer containing a carboxyl group-containing polymer may contain a polymer containing two or more carboxyl groups, as well as polyalcohols such as polyvinyl alcohol and glycerin. The polymer containing two or more carboxyl groups and polyvinyl alcohol are mixed in a weight ratio of 99:1 to 20:80.

The layer containing a polyvalent metal compound is formed by mixing the metal compound described above with a mixed resin such as alkyd resin, melamine resin, acrylic resin, urethane resin, nitrocellulose, epoxy resin, polyester resin, phenol resin, amino resin, fluororesin, isocyanate. It is a layer mixed with at least one resin selected from the group of. The weight ratio of the polyvalent metal compound to the resin (metal compound/resin) is from 0.01 to 1,000. The polyvalent metal compound is mixed in the resin layer in the form of particles having an average particle size of 15 nm to 500 nm.

In the present invention, the barrier coat layer is a chemical vapor deposition layer, a resin obtained by mixing a carboxyl group-containing polymer and a polyvalent metal compound, water, alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; N, N - Dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate. It can be laminated and its thickness is 0.1 to 10 μm.

Alternatively, the chemical vapor deposition layer is first laminated with a layer containing a carboxyl group-containing polymer. This lamination is carried out by adding a carboxyl group-containing polymer and other necessary additives to alcohols such as water, methyl alcohol, ethyl alcohol and isopropyl alcohol; A coating liquid dissolved or dispersed in a solvent is coated and dried, and the thickness thereof is 0.1 to 10 μm.

Next, the polyvalent metal compound and the resin are dissolved or dispersed in a solvent such as acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate, in addition to the above solvents, using a coating solution containing a carboxyl group. A layer containing a polyvalent metal compound is laminated with a thickness of 0.1 to 10 μm by coating and drying a resin layer containing a polymer.

By laminating the layer containing the polyvalent metal compound on the resin layer containing the carboxyl group-containing polymer in this manner, the carboxyl group-containing polymer is ion-crosslinked by the polyvalent metal ions migrated from the layer containing the polyvalent metal compound. It becomes a cured resin film. In order to promote migration of polyvalent metal ions, aging may be performed in a heated environment of 30 to 130° C. after forming the two layers.

(surface treatment)
In the present invention, the barrier coat layer may be further surface-treated to improve adhesion with the second physical vapor deposition layer. Such surface treatments include corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, and pretreatment such as oxidation treatment using chemicals.

Among such surface treatments, corona treatment and plasma treatment are particularly preferred. For example, as plasma treatment, there is plasma treatment in which surface modification is performed using plasma gas generated by ionizing gas by arc discharge. Inorganic gases such as oxygen gas, nitrogen gas, argon gas, and helium gas can be used as the plasma gas in addition to the above. For example, by performing plasma treatment in-line, it is possible to remove moisture, dust, etc. from the surface of the substrate layer and to perform surface treatments such as smoothing and activation of the surface. In addition, plasma treatment can be performed after vapor deposition to improve adhesiveness. In the present invention, plasma discharge treatment is preferably performed in consideration of plasma output, type of plasma gas, supply amount of plasma gas, treatment time, and other conditions. As a method for generating plasma, devices such as DC glow discharge, high frequency discharge, and microwave discharge can be used. Plasma treatment can also be performed by an atmospheric pressure plasma treatment method.

(Second physical vapor deposition layer)
The second physical vapor deposition layer constituting the barrier film according to the present invention is a vapor deposition film formed by a physical vapor deposition method (PVD method). In the present invention, it is preferable to form an aluminum deposition film as the second physical vapor deposition layer. By forming an aluminum deposition film as the second physical vapor deposition layer, it is possible to improve the light shielding property while improving the gas barrier property.

Examples of the physical vapor deposition method (PVD method) include a vacuum deposition method, a sputtering method, an ion plating method, an ion cluster beam method, and the like. Specifically, for example, a vapor deposition film can be formed by using a vacuum vapor deposition method or the like in which aluminum is used as a raw material, heated to vaporize it, and vapor deposited on one of the substrate layers (resin film). can. In addition, as a method of heating the vapor deposition material, for example, a resistance heating method, a high frequency induction heating method, an electron beam heating method (EB), or the like can be used.

The thickness of the deposited aluminum film is preferably 20 nm or more and 500 nm or less, more preferably 30 nm or more and 500 nm or less, and more preferably 40 nm or more and 500 nm or less. If the film thickness of the vapor-deposited aluminum film is within the above range, it is possible to further improve the light shielding property while exhibiting sufficient gas barrier property.

<Application>
The barrier film according to the present invention can be applied to products in various fields that require advanced gas barrier properties, light shielding properties, waterproof adhesion, and the like. Examples include products such as moisture-proof sheets, heat insulating materials, packaging materials, and medical instruments. When used in these products, the provision of a barrier layer comprising the barrier film of the present invention can improve gas barrier properties, light shielding properties, and waterproof adhesion.

<Manufacture of barrier film>
[Example 1]
A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared as a base layer. Next, the PET film was surface-treated with oxygen plasma under the following conditions.
(Plasma treatment conditions)
・Input power 0.3 kW
・Gas composition O ₂
・Gas flow rate 900 sccm
・Chamber pressure 3 Pa
・Film transport speed 4m/min

Subsequently, the PET film was mounted on the delivery roll of the plasma chemical vapor deposition apparatus, and then, on the oxygen plasma-treated surface of the PET film, under the following conditions, using a reactive resistance heating method as a heating means for the vacuum deposition method, An aluminum oxide deposition film (first physical vapor deposition layer) having a thickness of 20 nm was formed.
(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa

Further, according to the composition shown in Table 1, the previously prepared hydrolyzate of composition B was added to the mixed solution of composition A prepared in advance, and the mixture was stirred to obtain a colorless and transparent barrier coat composition.

Next, the barrier coating composition prepared above was coated on the evaporated aluminum oxide film by a direct gravure method. After that, heat treatment was performed at 140° C. for 60 seconds to form a barrier coat layer having a thickness of 0.3 μm (in a dry state).

Subsequently, plasma treatment was performed on the barrier coat layer using a glow discharge plasma generator, applying 1.0 slm of argon and 20 A of current. After that, aluminum was used as a raw material on the plasma-treated surface, and the degree of vacuum in the vacuum chamber was set to 2×10 ⁻⁴ mbar by a vacuum deposition method using electron beam heating, and the degree of vacuum in the deposition chamber was set to 2.0. Under conditions of × 10 ^-2 mbar, a 40 nm-thick aluminum vapor deposition film (physical vapor deposition layer) was formed to form a barrier film (layer structure: PET (oxygen plasma-treated surface)/aluminum oxide vapor deposition film (first physical vapor deposition layer)/barrier coat layer/aluminum deposition film (second physical vapor deposition layer)).

[Example 2]
Barrier film (layer structure: PET (oxygen plasma-treated surface)/aluminum oxide vapor deposition) in the same manner as in Example 1, except that the thickness of the aluminum oxide vapor deposition film (first physical vapor deposition layer) was changed to 40 nm A film (first physical vapor deposition layer)/barrier coat layer/aluminum vapor deposition film (second physical vapor deposition layer)) was obtained.

[Comparative Example 1]
A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared as a base layer. Subsequently, the PET film was subjected to plasma treatment using a glow discharge plasma generator, applying 1.0 slm of argon and a current of 20 A. After that, aluminum was used as a raw material on the plasma-treated surface, and the degree of vacuum in the vacuum chamber was set to 2×10 ⁻⁴ mbar by a vacuum deposition method using electron beam heating, and the degree of vacuum in the deposition chamber was set to 2.0. A barrier film (layer structure: PET/aluminum vapor deposition film (physical vapor deposition layer)) was obtained by forming an aluminum deposition film (physical vapor deposition layer) having a thickness of 40 nm under conditions of × 10 ^-2 mbar. .

[Comparative Example 2]
A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared as a base layer. Subsequently, the PET film was subjected to plasma treatment using a glow discharge plasma generator, applying 1.0 slm of argon and a current of 20 A. After that, aluminum was used as a raw material on the plasma-treated surface, and a vacuum deposition method using an electron beam heating method was performed to set the degree of vacuum in the vacuum chamber to 2.times.10.sup. ^-4 mbar, and the degree of vacuum in the deposition chamber to 2.0 mbar. It was sublimed under the condition of 0×10 ⁻² mbar and mixed with 10 slm of oxygen gas to form a 20 nm-thick aluminum oxide deposition film (physical vapor deposition layer).

Next, a barrier coat layer was formed in the same manner as in Example 1 on the deposited aluminum oxide film.

Subsequently, plasma treatment was performed on the barrier coat layer using a glow discharge plasma generator, applying 1.0 slm of argon and 20 A of current. After that, aluminum oxide was used as a raw material on the plasma-treated surface, and a vacuum deposition method using an electron beam heating method was performed to set the degree of vacuum in the vacuum chamber to 2.times.10.sup. ^-4 mbar, and the degree of vacuum in the deposition chamber to 2.0 mbar. It is sublimed under the conditions of 0×10 ⁻² mbar and mixed with 10 slm of oxygen gas to form a 20 nm-thick aluminum oxide deposition film (physical vapor deposition layer) to form a barrier film (layer structure: PET/aluminum oxide A deposition film (physical vapor deposition layer)/barrier coat layer/aluminum oxide deposition film (physical vapor deposition layer)) was obtained.

[Comparative Example 3]
A barrier film (layer structure: PET/silicon oxide vapor deposition film (chemical vapor deposition layer) was prepared in the same manner as in Example 1, except that an aluminum oxide vapor deposition film was formed instead of the aluminum vapor deposition film as the physical vapor deposition layer. /barrier coat layer/aluminum oxide deposition film (physical vapor deposition layer)).

[Comparative Example 4]
A barrier film (layer structure: PET/aluminum oxide vapor deposition film (physical vapor deposition layer) was prepared in the same manner as in Comparative Example 2, except that an aluminum vapor deposition film was formed instead of the aluminum oxide vapor deposition film as the physical vapor deposition layer. /barrier coat layer/aluminum deposition film (physical vapor deposition layer)).

<Performance evaluation of barrier film>
The barrier films produced in the above examples and comparative examples were subjected to the following measurements.

(Measurement of oxygen permeability)
For the barrier film, the oxygen permeability (cc/m ² *atm*day) was measured. Table 2 shows the measurement results.

(Measurement of water vapor permeability)
For the barrier film, the hot water vapor permeability (g/m ²・day) was measured. Table 2 shows the measurement results.

(Measurement of total light transmittance)
The total light transmittance (%) of the barrier film was measured using a turbidity meter (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1. Table 2 shows the measurement results.

<Production of laminate film>
First, a main agent containing polyester as a main component, a curing agent containing an aliphatic polyisocyanate, and ethyl acetate were mixed so that the weight compounding ratio of the main agent: curing agent: ethyl acetate was 10:1:14. A liquid curable polyester urethane adhesive was prepared.

Subsequently, using the polyester urethane-based adhesive, the physical vapor deposition layer surface of the barrier film and the adherend (unstretched polypropylene film 70MC) were laminated together to obtain a laminate film.

Also, the laminate film obtained above was stored for 120 hours under an environment of 60° C. temperature and 90% RH.

(Evaluation of waterproof adhesion)
For each of the laminated film obtained above and the laminated film after storage in a high-humidity environment, a sample piece was prepared by partially exfoliating at the barrier film/adherend interface, and immersed in tap water for 1 minute. Then, using a tensile tester (Tensilon universal tester RTC1310A, manufactured by Orientec), T-shaped peeling was performed at a measurement speed of 50 mm/min to measure the water resistant adhesive strength (N/15 mm). Table 2 shows the measurement results.

(Evaluation of laminate film)
Regarding the laminate film obtained above and the laminate film after storage in a high-humidity environment, the oxygen permeability, water vapor permeability, and total light transmittance were measured in the same manner as the performance evaluation of the barrier film. Table 2 shows the measurement results.

REFERENCE SIGNS LIST 10 barrier film 11 substrate layer 12 first physical vapor deposition layer 13 barrier coat layer 14 second physical vapor deposition layer

Claims (15)

A barrier film comprising a substrate layer, a first physical vapor deposition layer, a barrier coat layer, and a second physical vapor deposition layer in this order,
An oxygen plasma-treated surface is formed on the base material layer,
forming the first physical vapor deposition layer on the oxygen plasma-treated surface;
A plasma-treated surface is formed on the barrier coat layer,
forming the second physical vapor deposition layer on the plasma-treated surface;
The barrier film, wherein the first physical vapor deposition layer is an aluminum oxide deposition film. 2. The barrier film of claim 1, wherein said second physical vapor deposition layer is an aluminum vapor deposition film. 3. The barrier film according to claim 1 or 2, wherein the base layer is a biaxially oriented polyethylene terephthalate film. The barrier film according to any one of claims 1 to 3, wherein the barrier coat layer is a cured resin film of metal alkoxide and water-soluble polymer. The barrier film according to any one of claims 1 to 3, wherein the barrier coat layer is a cured resin film containing a reaction product obtained by reacting a metal oxide and a phosphorus compound. The barrier film according to any one of claims 1 to 3, wherein the barrier coat layer is a cured resin film containing a carboxyl group-containing polymer crosslinked with a polyvalent metal compound. Any one of claims 1 to 6, wherein the acidity permeability measured according to JIS K7126 in an environment of temperature 23°C and humidity 90% RH is 1.0 cc/m ² ·atm · day or less. The barrier film described in . The water vapor permeability measured according to JIS K7129 in an environment with a temperature of 40° C. and a humidity of 100% RH is 1.0 g/m ² ·day or less, according to any one of claims 1 to 7. barrier film . The barrier film according to any one of claims 1 to 8, which has a total light transmittance of 10% or less as measured according to JIS K7361. A moisture-proof sheet comprising the barrier film according to any one of claims 1 to 9. A heat insulating material comprising the barrier film according to any one of claims 1 to 9. A packaging material comprising the barrier film according to any one of claims 1-9. A laminate film comprising the barrier film according to any one of claims 1 to 9. A method for producing a barrier film according to any one of claims 1 to 9,
forming the oxygen plasma-treated surface by subjecting the base material layer to an oxygen plasma treatment;
forming the first physical vapor deposition layer on the oxygen plasma-treated surface;
forming the barrier coat layer on the first physical vapor deposition layer;
forming the plasma-treated surface by subjecting the barrier coat layer to plasma treatment;
forming the second physical vapor deposition layer on the plasma-treated surface;
A method of making a barrier film, comprising: 15. The method for producing a barrier film according to claim 14, wherein the plasma treatment is applied to the barrier coat layer using argon gas.

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