JP2018158501A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film which is excellent in gas barrier performance, and can suppress lowering of gas barrier performance even after a test under a severe high temperature and high humidity condition, so-called, a boil test and a retort test.SOLUTION: A gas barrier film has a protective coat layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent through an inorganic layer on at least one surface of a base film, where the silane coupling agent has a secondary amino group, a concentration of the silane coupling agent in the protective coat layer is 1.wt.% or more and 90 wt.% or less, and a thickness of the protective coat layer is 0.1 μm or more and 5 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a gas barrier film. More specifically, the present invention relates to a gas barrier film that can maintain excellent gas barrier properties even after a high temperature and high humidity test.

  Packaging films used for foods, pharmaceuticals, precision electronic parts, etc. are required to have gas barrier properties, resistance to mechanical external forces, and high transparency. As gas barrier films constituting the packaging films, base film The thing which provided the resin layer excellent in the inorganic layer and gas barrier property on the top is proposed.

For example, Patent Document 1 discloses a barrier composite film in which at least one surface of a base film layer is coated with a barrier resin layer containing a silane coupling agent via an inorganic thin film layer. Specifically, it is described that the barrier resin layer contains a vinylidene chloride copolymer or an ethylene-vinyl alcohol copolymer.
Further, in Patent Document 2, an inorganic oxide vapor-deposited thin film is provided on one surface of a base film, and an ethylene-vinyl alcohol copolymer is added to the main film of the vehicle on the inorganic oxide vapor-deposited thin film. Disclosed is a barrier film characterized in that a cured coating film is provided as a component and a resin composition containing at least a metal alkoxide compound.

JP-A-8-309913 JP 2000-62079 A

In Patent Document 1, the barrier composite film is stored for 1 week under the conditions of 40 ° C. and 90% relative humidity, the adhesion strength of the resin layer before and after storage is measured, and the change in adhesion under high temperature and high humidity is measured. Although it is evaluated, according to the study of the present inventors, the gas barrier property of the barrier composite film is greatly reduced after a test under severer high temperature and high humidity conditions, that is, a so-called boil test or retort test. It turns out that there is a fear.
Further, the inventors of the present invention have found that the barrier film of the above-mentioned Patent Document 2 has a possibility that the gas barrier property may be significantly reduced after the boil test and the retort test, similarly to the barrier composite film of Patent Document 1. did.

  The present invention has been made in view of the above situation, and the object of the present invention is excellent in gas barrier performance, and even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test. It is providing the gas barrier film which can suppress a fall.

As a result of intensive studies to solve the above problems, the present inventor has a protective coating layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent via an inorganic layer on at least one surface of the base film. By using a silane coupling agent having a specific structure in a gas barrier film, the gas barrier performance of the gas barrier film is excellent even after tests under severe high-temperature and high-humidity conditions, so-called boil tests and retort tests. The present invention has been found.
That is, the present invention is as follows.

[1] A gas barrier film having a protective coating layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent on at least one surface of a base film via an inorganic layer,
The silane coupling agent has a secondary amino group, the concentration of the silane coupling agent in the protective coating layer is 1% by weight or more and 90% by weight or less, and the thickness of the protective coating layer is 0.1 μm or more. A gas barrier film characterized by being 5 μm or less.
[2] An acrylic having an anchor coat layer between the base film and the inorganic layer, and the anchor coat layer having, as a polymerization component, an acrylic monomer having a polyester resin, a nitrocellulose resin, an alicyclic ring or an aromatic ring. Gas barrier film as set forth in [1], which contains a system resin and a mixture thereof.
[3] The gas barrier film according to [1] or [2], wherein the inorganic layer is silicon oxide.
[4] A packaging film using the gas barrier film according to any one of [1] to [3].

  The gas barrier film of the present invention is excellent in gas barrier performance, and can suppress a decrease in adhesion between each layer and a decrease in gas barrier performance even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test. It can be suitably used as various packaging films for foods, pharmaceuticals, precision electronic parts and the like.

Hereinafter, although the gas barrier film according to the present invention and the materials constituting them will be described in detail, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention. It is not limited to these contents.
In the present specification, the term “main component” is intended to allow other components to be included within a range that does not interfere with the action / effect of the gas barrier film of the present invention. Further, this term does not limit the specific content, but it is 50% by weight or more, preferably 65% by weight or more, more preferably 80% by weight or more, and 100% by weight or less of the total components. It is a component that occupies a range.

The gas barrier film according to the embodiment of the present invention includes a base film, an inorganic layer, and a protective coat layer in this order. Hereinafter, each material constituting the gas barrier film will be described.

<1. Base Film>
As the base film according to the present invention, a resin film is preferable, and the material can be used without any limitation as long as it is a resin that can be used for packaging materials used in foods, pharmaceuticals, precision electronic parts and the like. . Specifically, polyolefins such as homopolymers or copolymers such as ethylene, propylene and butene, amorphous polyolefins such as cyclic polyolefin, polyesters such as polyethylene-terephthalate (PET) and polyethylene-naphthalate (PEN), nylon 6, nylon 66, nylon 12, polyamide such as copolymer nylon, ethylene-vinyl acetate copolymer partial hydrolyzate, polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polycarbonate, polyvinyl butyral, Examples include polyarylate, fluororesin, acrylic resin, and biodegradable resin. In these, polyester, polyamide, or polyolefin is preferable from points, such as a film physical property and cost. The base film preferably has one or more of these resins as a main component.

Among these, from the viewpoint of transparency and film physical properties, the base film is preferably a film containing polyester as a main component, and more preferably a PET film containing PET as a main component or a PEN film containing PEN as a main component.

The surface of the substrate film according to the present invention is preferably subjected to easy adhesion treatment such as corona discharge treatment and plasma treatment in order to enhance adhesion.

The base film according to the present invention is a known additive, for example, an antistatic agent, a light blocking agent, an ultraviolet absorber, a plasticizer, a lubricant, a filler, a colorant, a stabilizer, a lubricant, a crosslinking agent, or an antiblocking agent. And an antioxidant and the like.

The base film according to the present invention can be produced by a conventionally known method. For example, the raw material is melted by an extruder, extruded by an annular die or a T-die, and rapidly cooled to be oriented substantially amorphously. An unstretched film can be produced. Further, by using a multilayer die, a single layer film made of one kind of resin, a multilayer film made of one kind of resin, a multilayer film made of various kinds of resins, and the like can be produced.

The unstretched film is subjected to a known method such as uniaxial stretching, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching, and tubular simultaneous biaxial stretching, and the film flow (vertical axis) direction or the film flow direction By stretching in a direction perpendicular to it (horizontal axis), a film stretched in a uniaxial direction or a biaxial direction can be produced, and the stretching ratio can be arbitrarily set.
When using a stretched film as the substrate film according to the present invention, from the viewpoint of transparency and film properties, a biaxially stretched PEN film, a biaxially stretched PET film, a coextruded biaxially stretched film of PEN and PET, or a resin thereof. And other resin coextruded biaxially stretched films are preferred, and biaxially stretched PEN films or biaxially stretched PET films are more preferred.

  The thickness of the base film according to the present invention is not particularly limited, but is usually 5 μm or more and 200 μm or less. Within this range, there is little risk of wrinkling or film breakage when forming the inorganic layer or protective coating layer, and the film is flexible, so that it can be easily processed with a winding device or the like. Become. Preferably they are 8 micrometers or more and 100 micrometers or less.

<2. Inorganic layer>
In the present invention, the inorganic layer bears gas barrier performance and is formed on at least one surface of the base film.

Examples of the inorganic substance constituting the inorganic layer according to the present invention include silicon, aluminum, magnesium, zinc, tin, nickel, titanium, or oxides, carbides, nitrides, oxycarbides, oxynitrides, oxycarbonitrides of these. , Diamond-like carbon, and mixtures thereof.
In view of maintaining high moisture resistance stably, silicon or aluminum oxides, carbides, nitrides, oxycarbides, oxynitrides, oxycarbonitrides, and mixtures thereof are preferable. Among these, oxidation of silicon or aluminum is preferable. At least one selected from the group consisting of oxides, oxynitrides, and nitrides is more preferable, and silicon oxide is more preferable in that the refractive index is low, the reflectance can be suppressed, and the antiglare property can be further increased.
Furthermore, if the inorganic layer according to the present invention is silicon oxide, the gas barrier film according to the present invention has particularly excellent gas barrier properties even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test. Is known to show.
The reason for this is that the silane coupling agent having a secondary amino group contained in the protective coating layer according to the present invention and the silicon oxide layer surface undergo a crosslinking reaction, and the interlayer adhesion between the inorganic layer and the protective coating layer is improved. Even after the so-called boil test and retort test, it is conceivable that the gas barrier performance of the gas barrier film is prevented from lowering.

As the method for forming the inorganic layer according to the present invention, any method such as a vapor deposition method and a coating method can be used, but the vapor deposition method is preferable in that a uniform thin film having a high gas barrier property can be obtained.
The vapor deposition method includes all methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD).
Examples of the physical vapor deposition include vacuum deposition, ion plating, and sputtering. Examples of the chemical vapor deposition include a catalytic CVD that uses a plasma CVD using a plasma and a catalytic catalyst that thermally decomposes a material gas using a heating catalyst body. Examples include chemical vapor deposition (Cat-CVD). In the atomic layer deposition method, atoms of a raw material compound are adsorbed on the surface of each monolayer on a substrate placed in a vacuum vessel, a film is formed by a reaction, and an excess molecule is removed by a purge. This is a method of stacking layers one by one.
In addition, the inorganic layer according to the present invention may be a single layer or multiple layers, and it is possible to increase the moisture resistance by forming multiple layers using the various film formation methods mentioned above. In that case, the same film formation method may be used, or a different film formation method may be used for each layer. However, it is efficient to improve moisture resistance and productivity by continuously performing them under reduced pressure. This is preferable.
Moreover, when the inorganic layer which concerns on this invention is a multilayer, each layer may consist of the same inorganic substance, or may consist of a different inorganic substance.

  The thickness of the inorganic layer according to the present invention is preferably 5 nm or more and 500 nm or less, more preferably 10 nm or more and 200 nm or less, more preferably 10 nm or more and 100 nm, from the viewpoint of high moisture-proof performance, transparency and workability. The following is more preferable, and 20 nm or more and 50 nm or less are more preferable.

<3. Protective coat layer>
The protective coating layer according to the present invention bears the gas barrier performance together with the inorganic layer, and also protects the inorganic layer, and has a gas barrier performance even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test. It aims at suppressing a fall and is formed in the surface at the side of the non-base film of the said inorganic layer.

The protective coating layer according to the present invention includes an ethylene-vinyl alcohol copolymer and a silane coupling agent having a secondary amino group, and the concentration of the silane coupling agent in the protective coating layer is 1% by weight or more and 90% by weight. It is important that: By containing an ethylene-vinyl alcohol copolymer and a predetermined amount of a silane coupling agent having a secondary amino group, the gas barrier film can be used even after tests under severe high temperature and high humidity conditions, so-called boil tests and retort tests. A decrease in gas barrier performance can be suppressed.
The protective coating layer according to the present invention can be formed by applying the protective coating agent to the inorganic layer.

The protective coating agent for forming the protective coating layer according to the present invention contains an ethylene-vinyl alcohol copolymer.
The ethylene content of the ethylene-vinyl alcohol copolymer contained in the protective coating agent is preferably 10 mol% or more and 60 mol% or less.
If it is this range, it exists in the tendency which can maintain the gas-barrier property in a high-humidity environment, and can also ensure water solubility.
More preferably, it is 20 mol% or more and 50 mol% or less, More preferably, it is 25 mol% or more and 45 mol% or less.
The ethylene-vinyl alcohol copolymer preferably has a weight average molecular weight of 100 or more and 5000 or less. Within this range, gas barrier properties and water solubility tend to be compatible.
The saponification degree of the ethylene-vinyl alcohol copolymer is preferably 80 mol% or more, and more preferably 95 mol% or more. If it is this range, it exists in the tendency which can ensure gas-barrier property. Although an upper limit is not specifically limited, Usually, it is 100 mol% or less.

In the protective coat layer according to the present invention, the concentration of the ethylene-vinyl alcohol copolymer is preferably 10% by weight or more and 99% by weight or less.
Within this range, even after tests under severe high-temperature and high-humidity conditions, so-called boil tests and retort tests, the gas barrier properties and bending resistance of the protective coating layer, and the adhesion between the protective coating layer and the inorganic layer are good. There is a tendency.
More preferably, it is 20 to 95 weight%, More preferably, it is 50 to 90 weight%.

The protective coating agent for forming the protective coating layer according to the present invention includes a silane coupling agent having a secondary amino group.
The silane coupling agent having a secondary amino group is more excellent in gas barrier properties of the gas barrier film than when a silane coupling agent having another functional group is blended, and is tested under severe high temperature and high humidity conditions. Even after the so-called boil test and retort test, it is possible to suppress a decrease in gas barrier performance of the gas barrier film.
The reason why it becomes better when a silane coupling agent having a secondary amino group is blended is that the silane coupling agent having a primary amino group reacts with each other because the hydrolysis / condensation reaction rate is high. While the silane coupling agent having a tertiary amino group has a slow hydrolysis / condensation reaction rate, it tends to be insufficiently reacted during the formation process of the protective coat layer. Since the silane coupling agent having a secondary amino group has a moderate hydrolysis / condensation reaction rate, not only the reaction between silane coupling agents but also the cross-linking reaction with ethylene vinyl alcohol is effective during the process of forming the protective coating layer. Therefore, gas barrier properties after so-called boil tests and retort tests, and adhesion to inorganic layers It is considered to be good.

  Examples of the silane coupling agent having a secondary amino group include N-phenyl-3-aminopropyltrimethoxysilane, bis (3-triethoxysilylpropyl) amine, N-phenyl-3-aminopropyltriethoxysilane, and [3- (2,4-dinitrophenylamino) propyl] triethoxysilane and the like. From the viewpoint of adjusting the adhesion between the inorganic layer and the protective coating layer and the hydrolysis / condensation reactivity due to steric hindrance, the following formula A silane coupling agent represented by (1) or formula (2) is preferred.

(R ¹ O) ₃ SiC _l H _2l NHR ² (1)
l represents an integer of 1 to 6, R ¹ represents a methyl group, an ethyl group, or a propyl group, and a methyl group or an ethyl group is preferable. R ² represents a functional group having an aromatic ring or alicyclic structure such as a phenyl group, a cyclohexyl group, a benzyl group, and a naphthyl group, and among them, a phenyl group is preferable.

(R ³ O) ₃ SiC _m H _2m NHC _n H _2n Si (OR ⁴ ) ₃ (2)
m and n each represent an integer of 1 to 6 and preferably coincide with each other. R ³ and R ^{4 each} represent a methyl group, an ethyl group, or a propyl group, and preferably coincide with each other, and in particular, both are preferably a methyl group or an ethyl group.

Especially, the silane coupling agent shown by Formula (1) is more preferable, and specifically, N-phenyl-3-aminopropyltrimethoxysilane is particularly preferable.

In the protective coating layer according to the present invention, it is important that the concentration of the silane coupling agent having a secondary amino group is 1% by weight or more and 90% by weight or less.
If it is this range, it exists in the tendency which can maintain the adhesiveness of an inorganic layer and the said protective coating layer, the gas barrier property of the said protective coating layer, and bending resistance.
Preferably they are 2 weight% or more and 50 weight% or less, More preferably, they are 5 weight% or more and 20 weight% or less.

The protective coating agent for forming the protective coating layer according to the present invention may contain known additives in addition to the components described above.
Examples of such additives include resins having gas barrier properties such as vinylidene chloride polymers and polyvinyl alcohol polymers, other resins, silane coupling agents other than those described above, antioxidants, weather resistance stabilizers, and ultraviolet absorbers. , Antistatic agents, pigments, dyes, antibacterial agents, lubricants, inorganic fillers and antiblocking agents.

It is important that the thickness of the protective coating layer according to the present invention is 0.1 μm or more and 5 μm or less.
If it is this range, productivity will be good and the printability of the surface of the said protective coating layer will become favorable, maintaining gas barrier property.
Preferably they are 0.1 micrometer or more and 4 micrometers or less, More preferably, they are 0.1 micrometer or more and 3 micrometers or less.

As a method for forming a protective coating layer according to the present invention, an ethylene-vinyl alcohol copolymer, a silane coupling agent having a secondary amino group, and other predetermined materials are mixed with a solvent to form a protective coating agent. The method is adopted as appropriate.
The solvent is preferably an aqueous solvent, and water or an organic solvent miscible with water, such as methanol, ethanol, propanol, isopropanol, butanol, tertiary butanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene A mixed solution with glycol monobutyl ether, diethylene glycol, acetone, methyl ethyl ketone and the like can be mentioned. These may be used alone or in combination of two or more.

As the coating method, for example, any of a coating method using a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, a bar coater, a spray and the like can be used. Moreover, after forming an inorganic layer in a base film, you may immerse in a protective coating agent. After coating, a uniform protective coat layer is formed by evaporating the solvent using a known drying method such as hot air drying at a temperature of about 80 to 200 ° C., heat roll drying, or infrared drying. Is done.

<4. Anchor coat layer>
In the present invention, an anchor coat layer may be provided between the base film and the inorganic layer for the purpose of improving the adhesion between the base film and the inorganic layer.
An anchor coat layer can be formed by applying an anchor coat agent to the surface of a base film.

  The anchor coating agent contains a binder component, specifically, polyester resin, urethane resin, acrylic resin, nitrocellulose resin, silicone resin, polyvinyl alcohol resin, ethylene-vinyl alcohol resin, etc. And vinyl alcohol resins, vinyl ester resins, epoxy resins, isocyanate group-containing resins, carbodiimide group-containing resins, alkoxyl group-containing resins, oxazoline group-containing resins, and styrene resins. These binder components may be used alone or in combination of two or more.

As the binder component, from the viewpoint of the hot water resistance of the anchor coat layer, that is, from the viewpoint of suppressing the deterioration of the gas barrier performance of the gas barrier film even after a test under severe high-temperature and high-humidity conditions, the so-called boil test or retort test. Therefore, an acrylic resin having a polyester resin, a nitrocellulose resin, an acrylic monomer having an alicyclic ring or an aromatic ring as a polymerization component, and a mixture thereof are preferable.
Since an acrylic resin having a polyester resin, a nitrocellulose resin, an acrylic monomer having an alicyclic ring or an aromatic ring as a polymerization component and a mixture thereof are excellent in heat resistance and hydrophobicity, an anchor coat layer containing these as a binder component It is particularly preferable that the binder component includes an acrylic resin having a mixture of a polyester-based resin and a nitrocellulose resin or an acrylic monomer having an alicyclic ring or an aromatic ring as a polymerization component.

  The polyester resin used for the anchor coating agent can be obtained by reacting a polyvalent carboxylic acid component and a polyhydric alcohol component. Examples of the polyvalent carboxylic acid component include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, azelaic acid, and orthophthalic acid. Examples of the polyhydric alcohol component include ethylene-glycol, 1,2-propylene glycol, 1, Examples include 3-propylene glycol, 1,4-butanediol, diethylene-glycol, neopentyl glycol, dipropylene glycol and 1,6-hexanediol.

  The nitrocellulose resin used for the anchor coating agent can be obtained by esterifying part or most of the hydroxyl groups of cellulose with nitric acid. Nitrocellulose resins have various degrees of polymerization, and those having an average degree of polymerization of 30 to 150 are used from the viewpoint of the strength of the anchor coat layer and solubility in a solvent.

The acrylic resin used for the anchor coating agent is not particularly limited, and those obtained by polymerizing a polymerizable unsaturated monomer using a conventionally known polymerization method can be used.
Examples of the polymerizable unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and tertiary butyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and (meth) acrylic acid esters such as stearyl (meth) acrylate, and hydroxyethyl ( (Meth) acrylate, hydroxypropyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate and mono (meth) acrylate of polyester diol obtained from phthalic acid and propylene glycol (Meth) acrylic monomers having a hydroxyl group such as rate, (meth) acrylic monomers having other crosslinkable functional groups such as amino groups and carboxyl groups, and (meth) acrylic monomers having an acidic functional group such as (meth) acrylic acid, In addition, from the viewpoint of heat resistance and hydrophobicity of acrylic resin, (meth) acrylate having an aromatic ring such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol acrylate, and phenyl (meth) acrylate, and isobornyl Examples include (meth) acrylic monomers having an alicyclic ring such as (meth) acrylate, cyclohexyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate.
From the viewpoint of hot water resistance of the anchor coat layer, a (meth) acryl monomer having an alicyclic ring or an aromatic ring is preferable.

  The molecular weight of the polymer constituting the resin is preferably a number average molecular weight of 3,000 or more and 50,000 or less, more preferably 4, from the viewpoint of gas barrier properties and adhesion between the base film and the inorganic layer. 000 or more and 40,000 or less, more preferably 5,000 or more and 30,000 or less.

Moreover, it is preferable to make the anchor coating agent contain a curing agent such as an isocyanate compound and introduce cross-linking into the anchor coating layer.
Specific examples of the isocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate and dicyclohexylmethane diisocyanate, and aromatics such as xylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene diisocyanate, tolidine diisocyanate and naphthalene diisocyanate. Group polyisocyanate and the like. From the viewpoint of gas barrier properties and adhesion to the base film and the inorganic layer, a polyisocyanate having two or more isocyanate groups is preferable, and a polyisocyanate having three or more isocyanate groups is more preferable.

In addition to the components described above, various known solvents and additives can be blended in the anchor coating agent.
Such additives include aqueous epoxy resins, silane coupling agents, alkyl titanates, antioxidants, weathering stabilizers, UV absorbers, antistatic agents, pigments, dyes, antibacterial agents, lubricants, inorganic fillers and blocking. An inhibitor etc. can be mentioned.

The thickness of the anchor coat layer is preferably 0.1 nm or more and 1000 nm or less, more preferably 2 nm or more and 1000 nm or less, further preferably 5 nm or more and 1000 nm, and more preferably 10 nm or more and 500 nm or less. It is particularly preferred. If the thickness is 0.1 nm or more, a uniform layer can be formed, so that there is no variation in adhesion and the like. Further, if the thickness is 1000 nm or less, the adhesion is good, and transfer to the back side of the base film occurs when the anchor coat layer is applied to the base film surface offline and wound into a roll. Then, when an inorganic layer is formed on the anchor coat layer, a predetermined gas barrier performance can be exhibited.
In order to improve the water resistance and durability of the anchor coat layer, a crosslinking treatment by electron beam irradiation may be performed.

  As a method for forming the anchor coat layer, the above-described known coating method is appropriately adopted as a method for forming the protective coat layer.

<5. Gas barrier film>
The gas barrier film according to the present invention includes a protective coat layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent on at least one surface of a base film via an inorganic layer, and has a specific structure. By using a silane coupling agent, the gas barrier performance is excellent, and the gas barrier performance can be maintained even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test.

The gas barrier film according to the present invention preferably has a water vapor transmission rate of 0.10 g / m ² / day or less under conditions of a temperature of 40 ° C. and a relative humidity of 90%.
If it is 0.10 g / m ² / day or less, for example, when the gas barrier film is used as a part of the structure of the packaging film, the contents can be stored for a long time, and the storage period tends to be ensured.
More preferably, it is 0.05 g / m ² / day or less. On the other hand, although an upper limit is not specifically limited, Usually, it is 0.0001 g / m < ² > / day or more.

  The water vapor transmission rate under the conditions of a temperature of 40 ° C. and a relative humidity of 90% is determined according to JIS Z0222 “Moisture permeability test method for moisture-proof packaging containers” and JIS Z0208 “Moisture permeability test method for moisture-proof packaging materials (cup method)”. It can be measured according to the conditions.

The gas barrier film according to the present invention preferably has an oxygen permeability of 0.10 cc / m ² / day / atm or less under conditions of a temperature of 25 ° C. and a relative humidity of 80%.
If it is 0.10 cc / m ² / day / atm or less, for example, when the gas barrier film is used as a part of the structure of the packaging film, the contents can be stored for a long period and the storage period tends to be ensured. .
More preferably, it is 0.05 cc / m ² / day / atm or less. On the other hand, the upper limit is not particularly limited, but is usually 0.0001 cc / m ² / day / atm or more.

  The oxygen permeability can be measured according to the JIS K 7126b method, for example, with an oxygen permeability measuring device (“OX-TRAN 2/21 type oxygen permeability measuring device” manufactured by MOCON).

The gas barrier film according to the present invention has a water vapor transmission rate of 0.15 g / m ² / day under the conditions of a temperature of 40 ° C. and a relative humidity of 90% after so-called boiling (temperature: 100 ° C., time: 30 minutes). The following is preferable.
If it is 0.15 g / m ² / day or less, for example, when the gas barrier film is used as a part of the structure of the packaging film, the content of the content is long-term after being put in the packaging film and boiled. Storage is possible, and the storage period tends to be secured.
More preferably, it is 0.10 g / m ² / day or less. On the other hand, although an upper limit is not specifically limited, Usually, it is 0.0001 g / m < ² > / day or more.

The gas barrier film according to the present invention has an oxygen permeability of 0.25 cc / m ² / day under the conditions of a temperature of 25 ° C. and a relative humidity of 80% after a so-called boiling (temperature: 100 ° C., time: 30 minutes) treatment. / Atm or less is preferable.
If the gas barrier film is used as a part of the structure of the packaging film, for example, if the content is 0.25 cc / m ² / day / atm or less, the contents are put into the packaging film even after retorting. Can be stored for a long time, and the storage period tends to be secured.
More preferably 0.20cc ^/ m 2 ^/ day ^/ atm, more preferably not more than ^{0.15cc / m 2 / day / atm} . On the other hand, the upper limit is not particularly limited, but is usually 0.0001 cc / m ² / day / atm or more.

The gas barrier film according to the present invention preferably has a laminate strength of 400 g / 15 mm or more after so-called boiling (temperature: 100 ° C., time: 30 minutes) treatment.
If the gas barrier film is 400 g / 15 mm or more, for example, when the gas barrier film is used as a part of the structure of the packaging film, even if an external force is applied to the packaging film after the boil treatment, the separation between the layers hardly occurs and the contents are stable. Tend to enable long-term storage.
More preferably, it is 450 g / 15 mm or more, More preferably, it is 500 g / 15 mm or more. On the other hand, the lower limit is not particularly limited, but is usually 10,000 g / 15 mm or less.
The laminate strength can be measured by the method described later.

The gas barrier film according to the present invention has a gas barrier property, adhesion between layers, stabilization of each layer, etc. after forming an anchor coat layer, or after forming an inorganic layer, and further forming a protective coat layer. It is preferable to perform an aging treatment from the viewpoint.
The aging treatment has different conditions depending on the types of components constituting each layer of the gas barrier film and the thickness of the layer, but the method is not particularly limited as long as it can maintain the necessary temperature and time. For example, a method of storing in an oven or temperature-controlled room set to the required temperature, a method of blowing hot air, a method of heating with an infrared heater, a method of irradiating light with a lamp, a direct contact with a hot roll or hot plate For example, a method of imparting a microwave and a method of irradiating with a microwave can be used.
Moreover, even if it heat-processes, after cutting a film into the magnitude | size which is easy to handle, it may heat-process with a film roll. Furthermore, as long as the necessary time and temperature can be obtained, a heating device can be incorporated in a part of a film manufacturing apparatus such as a coater or a slitter, and heating can be performed in the manufacturing process.

  In the gas barrier film according to the present invention, an additional layer may be further laminated on the above-described constituent layer as required or necessary. For example, a gas barrier laminated film used for various applications can be obtained by laminating such as providing a plastic film on the protective coating layer. The thickness of the plastic film is usually selected in the range of 5 to 500 μm, preferably 10 to 200 μm from the viewpoints of mechanical strength, flexibility and transparency. Moreover, there is no restriction | limiting in particular in the width | variety and length of this film, It can select suitably according to a use. For example, by laminating a plastic film that can be heat-sealed on the surface of the protective coating layer, a gas-barrier laminated film that can be heat-sealed can be obtained and used as various packaging materials such as packaging films. Examples of heat-sealable plastic films include films made of known resins such as polyethylene resins, polypropylene resins, ethylene-vinyl acetate copolymers, ionomer resins, acrylic resins, and polylactic acid. Can be mentioned.

  Moreover, as another embodiment, a printing layer is formed on the protective sheet layer of the gas barrier film according to the present invention, and a heat seal layer is further laminated thereon. As the printing ink for forming the printing layer, a printing ink containing a water-soluble and solvent-soluble resin can be used. Here, examples of the resin used in the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate resins, and mixtures thereof. Furthermore, for printing inks, antistatic agents, light shielding agents, ultraviolet absorbers, plasticizers, lubricants, fillers, colorants, stabilizers, lubricants, antifoaming agents, crosslinking agents, anti-blocking agents, antioxidants, etc. These known additives may be added.

Although it does not specifically limit as a printing method for providing a printing layer, Well-known printing methods, such as an offset printing method, a gravure printing method, and a screen printing method, can be used. For drying the solvent after printing, known drying methods such as hot air drying, hot roll drying and infrared drying can be used.
It is also possible to laminate at least one paper or plastic film between the printing layer and the heat seal layer. As the plastic film, the same resin as that used for the base material of the gas barrier film according to the present invention can be used. Among these, paper, polyester resin, polyamide resin, or biodegradable resin is preferable from the viewpoint of obtaining sufficient rigidity and strength of the laminate.
<6. Applications of gas barrier film according to the present invention>

The gas barrier film according to the present invention described above is capable of suppressing a decrease in gas barrier performance even after a test under severe high temperature and high humidity conditions, that is, a so-called boil test or retort test. Due to such excellent characteristics, the present invention also provides a packaging body such as a packaging film having the gas barrier film.
The gas barrier film according to the present invention can be suitably used as a gas barrier film constituting a food packaging film that is particularly required to be resistant to tests under severe high temperature and high humidity conditions, so-called boil test and retort test. .

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the following examples. In addition, the evaluation method of the film in the following examples is as follows.

[Evaluation item]
(Water vapor transmission rate)
According to the conditions of JIS Z0222 “moisture-proof packaging container moisture permeability test method” and JIS Z0208 “moisture-proof packaging material moisture permeability test method (cup method)”, the following methods were used for evaluation.
A urethane adhesive (AD900 and CAT-RT85 manufactured by Toyo Morton Co., Ltd.) of 10: 1.5 is applied to the surface of a 60 μm-thick non-axially stretched polypropylene (CPP) film (“P1146” manufactured by Toyobo Co., Ltd.). The mixture was applied and dried to form an adhesive layer having a thickness of about 3 μm. On the adhesive layer, the coating layer surface side of the gas barrier film was laminated to obtain a gas barrier laminated film.
Using two gas barrier laminated films each having a moisture permeable area of 10.0 cm × 10.0 cm square, a bag having about 20 g of anhydrous calcium chloride as a hygroscopic agent and sealed on all sides was produced, and the bag was heated to a temperature of 40 ° C. and a relative humidity of 90 As a guideline, the weight increase was almost constant at intervals of 48 hours or longer, and mass measurement (0.1 mg unit) was performed up to 14 days, and the water vapor transmission rate was calculated from the following formula.
The water vapor permeability after the boil test was measured on the gas barrier laminate film by boiling (temperature: 100 ° C., time: 30 minutes) and thereafter the same as above.
Water vapor transmission rate [g / m2 / day] = (m / s) / t
m: Mass increase in the last two weighing intervals (g)
s; Moisture permeable area (m2)
t: Time of last two weighing intervals (h) / 24 (h)

(Oxygen permeability)
In accordance with JIS K 7126b method, each gas barrier laminate film was measured at a temperature of 25 ° C. and a relative humidity of 80% using an oxygen permeability measuring device (“OX-TRAN 2/21 type oxygen permeability measuring device” manufactured by MOCON). The oxygen transmission rate (cc / (m 2 · 24 hr · atm)) was measured under the conditions.
The oxygen permeability after the retort test was measured by performing the retort treatment (temperature: 125 ° C., time: 30 minutes) of the gas barrier laminate film, and thereafter measuring in the same manner as described above.

(Lamination strength)
The gas barrier laminate film obtained by the same method as described above was cut into a strip shape having a width of 15 mm, and subjected to the treatment as it is or boiled (temperature: 100 ° C., time: 30 minutes), and then part of the edge was peeled off. Using a tensile tester ("STA-1150" manufactured by Orientec Co., Ltd.), the CPP film was peeled 180 ° at a speed of 300 mm / min, whereby the laminate strength after untreated and boil tests (g / 15 mm) Was measured.
In addition, it shows that the adhesiveness between each layer is so favorable that the value of laminate strength is large.

(Inorganic layer thickness)
The film thickness of the inorganic layer was measured using fluorescent X-rays. This method uses the phenomenon of emitting fluorescent X-rays peculiar to atoms when they are irradiated with X-rays, and knowing the number (amount) of atoms by measuring the intensity of emitted fluorescent X-rays. I can do it. Specifically, a film having two known thicknesses is formed on the film, the specific fluorescent X-ray intensity emitted for each is measured, and a calibration curve is created from this information. Similarly, the fluorescent X-ray intensity was measured for the measurement sample, and the film thickness was measured from the calibration curve.

[Materials used]
(Base material)
-Biaxially stretched PET film (Mitsubishi Resin H100C, thickness 12 μm)
・ Unstretched polypropylene film (CPP) (P1146, Toyobo Co., Ltd., thickness 60 μm)
(Inorganic layer raw material)
・ SiO (silicon monoxide)
(Anchor coating agent)
・ Saturated polyester (Byron 300 manufactured by Toyobo Co., Ltd.)
・ Isocyanate compound (Coronate L manufactured by Tosoh Corporation)
(Protective coating agent)
・ Ethylene-vinyl alcohol copolymer (ethylene content 27 mol%) aqueous solution (ethylene-vinyl alcohol copolymer concentration is 5% by weight)
・ N-phenyl-3-aminopropyltrimethoxysilane (KBM-573 manufactured by Shin-Etsu Chemical Co., Ltd.) Silane coupling agent having secondary amino group ・ Bis (3-triethoxysilylpropyl) amine (EVONIK Co., Ltd.) Dynasylan 1122) Silane coupling agent having secondary amino group-3-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd. KBE-903) Silane coupling agent having primary amino group-3-glycidoxypropyltrimethoxy Silane (Shin-Etsu Chemical Co., Ltd. KBM-403) A silane coupling agent having an epoxy group.

(Preparation of anchor coating agent)
Saturated polyester (Toyobo Co., Ltd. Byron 300) and an isocyanate compound (Tosoh Co., Ltd. Coronate L) were blended at a mass ratio of 1: 1 to prepare an anchor coating agent.

(Preparation of protective coating agent 1)
An ethylene-vinyl alcohol copolymer aqueous solution is coated with N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM-573) at a solid content concentration of 10% by weight based on the total solid content in the protective coating. Protective coating agent 1 was prepared.

(Preparation of protective coating agent 2)
In an aqueous ethylene-vinyl alcohol copolymer solution, N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM-573) has a solid content concentration of 2% based on the total solid content in the protective coating agent. % Was added to prepare a protective coating agent 2.

(Preparation of protective coating agent 3)
In the ethylene-vinyl alcohol copolymer aqueous solution, bis (3-triethoxysilylpropyl) amine (EVONIK Co., Ltd. Dynasylan 1122) is added so that the solid content concentration becomes 10% by weight with respect to the total solid content in the protective coating agent. Protective coating agent 3 was prepared.

(Preparation of protective coating agent 4)
In an aqueous ethylene-vinyl alcohol copolymer solution, N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM-573) has a solid content concentration of 0. 0 with respect to the total solid content in the protective coating agent. It added so that it might become 5 weight%, and the protective coating agent 4 was prepared.

(Preparation of protective coating agent 5)
3-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd. KBE-903) is added to the ethylene-vinyl alcohol copolymer aqueous solution, and the solid content concentration becomes 10% by weight with respect to the total solid content in the protective coating agent. Thus, protective coating agent 5 was prepared.

(Preparation of protective coating agent 6)
3-glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM-403) was added to the ethylene-vinyl alcohol copolymer aqueous solution to a solid content concentration of 10% by weight with respect to the total solid content in the protective coating agent. Thus, a protective coating agent 6 was prepared.

(Preparation of protective coating agent 7)
An aqueous ethylene-vinyl alcohol copolymer solution was used as protective coating agent 7.

[Example 1]
A biaxially stretched polyethylene terephthalate film (Mitsubishi Resin Co., Ltd., H100C) having a thickness of 12 μm was used as the base film, and an anchor coat agent was applied to the corona-treated surface and dried to form an anchor coat layer having a thickness of 100 nm.
Next, SiO was evaporated by a heating method under a vacuum of 2 × 10 −3 Pa using a vacuum vapor deposition apparatus to form a 30 nm thick SiOx thin film layer on the anchor coat layer.
Subsequently, the protective coating agent 1 was applied and dried on the SiOx thin film layer to form a protective coating layer having a thickness of 0.5 μm to obtain a gas barrier film.
The obtained gas barrier film was subjected to water vapor transmission rate, water vapor transmission rate after boil test, oxygen transmission rate, oxygen transmission rate after retort test, laminate strength, and laminate strength measurement before and after the boil test. The results are shown in Table 1.

[Example 2]
In Example 1, a gas barrier film was obtained in the same manner except that an aging treatment was performed at 80 ° C. for 1 day after forming the protective coating layer. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
In Example 1, a gas barrier film was obtained in the same manner except that the thickness of the protective coat layer was 2 μm. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 2 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 3 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 4 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
A gas barrier film was obtained in the same manner as in Example 1 except that the thickness of the protective coating layer was 0.05 μm. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 5 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 6 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 5]
A gas barrier film was obtained in the same manner as in Example 1 except that the protective coating agent 7 was used instead of the protective coating agent 1. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 6]
In Example 1, a gas barrier film was obtained without forming a protective coat layer. The obtained gas barrier film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Discussion]
From the results of Examples 1 to 5, it is a gas barrier film having a protective coat layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent on at least one surface of a base film via an inorganic layer. The silane coupling agent has a secondary amino group, the concentration of the silane coupling agent in the protective coating layer is 1% by weight or more and 90% by weight or less, and the thickness of the protective coating layer is 0.1 μm. As described above, by being 5 μm or less, a gas barrier film that has excellent gas barrier performance and can suppress deterioration in gas barrier performance and laminate strength even after tests under severe high temperature and high humidity conditions, so-called boil test and retort test. It turns out that it is obtained.
On the other hand, from the results of Comparative Example 1 and Comparative Example 2, depending on the thickness of the protective coat layer and the concentration of the silane coupling agent having a secondary amino group, a test under severe high temperature and high humidity conditions, a so-called boil test, It was found that even after the retort test, the gas barrier performance and the laminate strength decreased greatly.
Further, from the results of Comparative Example 3 and Comparative Example 4, it was found that even when a silane coupling agent having no secondary amino group was added to the protective coating layer, excellent effects as shown in the examples were not exhibited. .

Claims (4)

A gas barrier film having a protective coating layer containing an ethylene-vinyl alcohol copolymer and a silane coupling agent on at least one surface of a base film through an inorganic layer,
The silane coupling agent has a secondary amino group, the concentration of the silane coupling agent in the protective coating layer is 1% by weight or more and 90% by weight or less, and the thickness of the protective coating layer is 0.1 μm or more. A gas barrier film characterized by being 5 μm or less. An acrylic resin having an anchor coat layer between the base film and the inorganic layer, and the anchor coat layer having, as a polymerization component, an acrylic monomer having a polyester resin, a nitrocellulose resin, an alicyclic ring or an aromatic ring; The gas barrier film according to claim 1, comprising a mixture thereof.   The gas barrier film according to claim 1 or 2, wherein the inorganic layer is silicon oxide. A packaging film using the gas barrier film according to any one of claims 1 to 3.