JP2020157717A - Barrier film and laminate material for paper container - Google Patents

Abstract

To provide a barrier film excellent in interlayer adhesive properties and gas barrier properties, in which the gas barrier properties are hard to deteriorate even after cutting or after forming a paper container.SOLUTION: A barrier film includes a primer layer, a barrier coat layer, a first inorganic oxide vapor-deposited layer, a substrate film and a second inorganic oxide vapor-deposited layer in this order. The primer layer includes a polyolefin polymer. The polyolefin polymer includes 0.01 to 5 mass% of an unsaturated carboxylic acid and/or a component derived from an anhydride thereof. The barrier coat layer is a cured film of a hydrolysate of a metalalkoxide and a water-soluble polymer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a barrier film, and more particularly, the primer layer, the barrier coat layer, the first inorganic oxide vapor deposition layer, the base film, and the second inorganic oxide vapor deposition layer are provided in this order. Regarding the barrier film.
Further, the present invention includes an outermost layer, a paper base material layer, a first thermosetting resin layer, a barrier layer made of the barrier film, a second thermosetting resin layer, and an innermost layer. It also relates to a laminated material for paper containers, which is prepared in this order.

Conventionally, as a barrier material against oxygen or water vapor, an inorganic oxide such as silicon oxide or aluminum oxide is formed on a film substrate by a vacuum deposition method, a sputtering method, an ion plating method, a chemical vapor deposition method, or the like. The transparent gas barrier film is attracting attention. As a barrier film, a barrier film provided with a metal foil such as aluminum foil has been used conventionally because it has excellent gas barrier properties, but it cannot be used for microwave ovens or it is opaque, so that the contents can be viewed easily. There was a problem of being inferior.

Further, in recent years, liquid paper containers having excellent gas barrier properties have been developed for filling and packaging liquids such as liquor, juice, mineral water, foods and drinks such as liquid seasonings, and chemical products. Examples of such a liquid paper container include those made by manufacturing a laminated material for a paper container having an outermost layer, a paper base material layer, an adhesive layer, a barrier layer and an innermost layer. Here, as the barrier layer, for example, a laminated film of a polyester film and an inorganic oxide-deposited polyester film is used (Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-312753

However, since the thin-film inorganic oxide film is a non-flexible thin film, cracks and the like are easily generated by heat and pressure applied from the outside during processing such as lamination or box making, and the gas barrier property is impaired. There was a problem. On the other hand, it has been studied to prevent the occurrence of cracks and the like by providing a gas barrier coating film on the vapor-deposited film of the inorganic oxide.

Further, the paper base material used in the laminated material for a paper container is required to have a certain thickness in order to obtain the independence and strength of the container. However, when a paper base material having a sufficient thickness is laminated with another base material via an adhesive layer, sufficient interlayer adhesion strength cannot be obtained and delamination is likely to occur.
In particular, when the paper base material is laminated with the gas barrier coating film of the barrier film, sufficient interlayer adhesive strength cannot be obtained, and the laminated material for paper containers in the box making process is punched into a blank plate and ruled line molding for bending. There is a problem that the barrier film in the laminated material and the paper base material or the resin layer caused by the peeling occur due to the embossing. Further, in a system for in-line box making from a roll-shaped laminate for a paper container, there is a similar problem of peeling in steps such as bending, embossing, and cutting. Further, there is a problem that sufficient gas barrier property is not exhibited due to this.

The present invention has been made in view of the above background technology, and an object of the present invention is to provide a barrier film which is excellent in interlayer adhesiveness and gas barrier property and whose gas barrier property is not easily deteriorated even after cutting or box making of a paper container. There is.

As a result of diligent studies to solve the above problems, the present inventors have made a specific primer layer, a specific barrier coat layer, a first inorganic oxide-deposited layer, a base film, and a second barrier film. It has been found that the above problems can be solved by laminating the inorganic oxide vapor deposition layers in this order. 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 primer layer, a barrier coat layer, a first inorganic oxide vapor deposition layer, a base film, and a second inorganic oxide vapor deposition layer in this order.
The primer layer contains a polyolefin polymer and contains
The polyolefin polymer contains 0.01% by mass or more and 5% by mass or less of a component derived from unsaturated carboxylic acid and / or its anhydride.
A barrier film is provided in which the barrier coat layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer.

In the above aspect of the present invention, it is preferable that the primer layer is formed by using an aqueous dispersion in which the polyolefin polymer is dispersed so that the number average particle size is 1 μm or less.

In the above aspect of the present invention, the content of the polyolefin polymer in the primer layer is preferably 50% by mass or more and 99% by mass or less.

In the above aspect of the present invention, the thickness of the primer layer is preferably 0.1 μm or more and 3 μm or less.

In the above aspect of the present invention, it is preferable that the first inorganic oxide-deposited layer is an aluminum oxide-deposited film or a silicon oxide-deposited film.

In the above aspect of the present invention, it is preferable that the second inorganic oxide-deposited layer is an aluminum oxide-deposited film or a silicon oxide-deposited film.

In the above aspect of the present invention, it is preferable that the barrier film is for a paper container.

According to another aspect of the invention
Lamination for paper containers, which comprises an outermost layer, a paper base material layer, a first thermosetting resin layer, a barrier layer, a second thermosetting resin layer, and an innermost layer in this order. It's a material
A laminated material for a paper container is provided in which the barrier layer is made of the above barrier film.

In another aspect of the present invention, it is preferable that the thermosetting resin constituting the thermosetting resin layer is an ethylene polymer having a carboxyl group or an acid anhydride group in the molecule.

In another aspect of the present invention, the primer layer of the barrier film is in contact with the first heat-sealing resin layer, and the second inorganic oxide-deposited layer of the barrier film is the second heat-melting. It is preferable to be in contact with the adhesive resin layer.

In another aspect of the present invention, the primer layer of the barrier film is in contact with the second heat-sealing resin layer, and the second inorganic oxide-deposited layer of the barrier film is the first heat-melting. It is preferable to be in contact with the adhesive resin layer.

In another aspect of the present invention, a resin layer is formed between the paper substrate layer and the first thermosetting resin layer and / or between the second thermosetting resin layer and the innermost layer. It is preferable to further prepare.

According to yet another aspect of the invention.
A paper container made by manufacturing the above-mentioned laminated material for a paper container is provided.

According to the present invention, it is possible to provide a barrier film which is excellent in interlayer adhesiveness and gas barrier property and whose gas barrier property is not easily deteriorated even after cutting or making a paper container. Further, it is possible to provide a laminated material for a paper container having excellent barrier properties using such a barrier film. Further, it is possible to provide a liquid paper container having an excellent barrier property, which is made by manufacturing such a laminated material for a paper container.

It is the schematic sectional drawing which showed one Embodiment of the barrier film of this invention. It is the schematic sectional drawing which showed one Embodiment of the laminated material for a paper container of this invention.

<Barrier film>
The barrier film according to the present invention includes a primer layer, a barrier coat layer, a first inorganic oxide-deposited layer, a base film, and a second inorganic oxide-deposited layer in this order. The barrier film having such a layer structure is excellent in interlayer adhesiveness and initial gas barrier property, and further, the gas barrier property is less likely to deteriorate even after cutting or making a paper container. Such a barrier film can be suitably used as a barrier layer for various containers and the like that require gas barrier properties and strong adhesiveness, and for example, can be suitably used as a barrier layer for laminated materials for paper containers. ..

The barrier film has an oxygen permeability measured in an environment of a temperature of 23 ° C. and a humidity of 90 RH%, preferably ^2.5 cc / m ² · day or less, and more preferably 1.0 cc / m ² · day or less. More preferably, it is 0.5 cc / m ² · day or less, and even more preferably 0.3 cc / m ² · day or less. If the oxygen permeability of the barrier film satisfies the above numerical range, it has a suitable oxygen barrier property, and therefore, when used as a barrier layer of a paper container, an adverse effect on the contents of the paper container can be suppressed. ..

The water vapor permeability of the barrier film measured in accordance with JIS K7129 is preferably 3.0 g / m ² · day or less, more preferably 1.0 g / m ² · day or less, and further preferably 0. is less than or equal to .5g ^/ m 2 · day. If the water vapor permeability of the barrier film satisfies the above numerical range, it has a suitable water vapor barrier property, and therefore, when used as a barrier layer of a paper container, an adverse effect on the contents of the paper container can be suppressed. ..

The layer structure of the barrier film of the present invention will be described with reference to the drawings. The barrier film 10 shown in FIG. 1 is provided with a first inorganic oxide-deposited layer 13 on one surface of the base film 11, a barrier coat layer 15 on the first inorganic oxide-deposited layer 13, and further. A primer layer 12 is provided on the barrier coat layer 15. Further, a second inorganic oxide vapor deposition layer 14 is provided on the other surface of the base film 11. Hereinafter, each layer constituting the barrier film of the present invention will be described.

(Base film)
The base film used in the barrier film of the present invention is not particularly limited, but has excellent chemical or physical strength, withstands conditions for forming a vapor-deposited film of an inorganic oxide, and its film characteristics. It is possible to use a resin film that can be held well without damaging the film. 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). Resin), poly (meth) acrylic resin, polycarbonate resin, polyvinyl alcohol resin, ethylene-vinyl ester copolymer saponified product, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, polyamide resin such as various nylons. , Polyurethane-based resin, acetal-based resin, cellulose-based resin, and other various resin films can be used.
In the present invention, among the above-mentioned resin films, it is particularly preferable to use a polyester-based resin, polyolefin-based resin, or polyamide-based resin film. As the base film, any of the unstretched resin films and the uniaxially or biaxially stretched resin films can be used.

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

(Polybutylene terephthalate film (PBT))
Polybutylene terephthalate film has a high thermal deformation temperature, excellent mechanical strength and electrical characteristics, and good molding processability. Therefore, when it is used as a packaging bag for storing contents such as food, it is used for retort treatment. It is possible to prevent the packaging bag from being deformed or its strength from being lowered. The polybutylene terephthalate film is a film containing polybutylene terephthalate (hereinafter, also referred to as PBT) as a main component, and is preferably a resin film containing 60% by mass or more of PBT.

(Biomass-derived polyester film)
The polyester film derived from biomass comprises 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 an ethylene glycol whose diol unit is derived from biomass and is a dicarboxylic acid unit. Polyester, which is a dicarboxylic acid derived from fossil fuel, is contained in an amount of 50 to 95% by mass, preferably 50 to 90% by mass, based on the entire resin composition.

Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass such as sugar cane and corn. For example, biomass-derived ethylene glycol can be obtained from biomass ethanol by a method of producing ethylene glycol via ethylene oxide by a conventionally known method. Further, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol Co., Ltd. can be preferably used.

As the dicarboxylic acid unit of polyester, a fossil fuel-derived dicarboxylic acid is used. As the dicarboxylic acid, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and derivatives thereof can be used. Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid, and examples of the derivative of the aromatic dicarboxylic acid include lower alkyl esters of the aromatic dicarboxylic acid, specifically, methyl ester, ethyl ester, propyl ester and butyl. Esters and the like can be mentioned. Among these, terephthalic acid is preferable, and dimethyl terephthalate is preferable as the derivative of the aromatic dicarboxylic acid.

The polyesters that may be contained in the resin composition forming the polyester film derived from biomass in a proportion of 5 to 45% by mass include polyesters derived from fossil fuels, recycled polyesters derived from fossil fuels, and polyester products derived from biomass. Recycled polyester.

(Recycled polyethylene terephthalate)
A polyethylene terephthalate film containing polyethylene terephthalate recycled by mechanical recycling. Specifically, a PET bottle is recycled by mechanical recycling. The PET contains ethylene glycol as a diol component and a terephthalic acid component as a dicarboxylic acid component. And contains 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 PET. Is more preferable.

Here, mechanical recycling generally refers to crushing a recovered polyethylene terephthalate resin product such as a PET bottle, cleaning it with an alkali to remove stains and foreign substances on the surface of the PET resin product, and then drying it under high temperature and reduced pressure for a certain period of time. This is a method in which the pollutants remaining inside the PET resin are diffused and decontaminated to remove stains on the resin product made of the PET resin, and the resin product is returned to the PET resin again.

The recycled polyethylene terephthalate preferably contains recycled PET in a proportion of 50% by weight or more and 95% by weight or less, and may contain virgin PET. As the virgin PET, the general diol component may be ethylene glycol, and the dicarboxylic acid component may be that of terephthalic acid and further containing isophthalic acid.

As the film of the above-mentioned various resins, for example, one or more of the above-mentioned various resins are used, and a film-forming method such as an extrusion method, a cast molding method, a T-die method, a cutting method, or an inflation method is used. A method of independently forming a film of the above-mentioned various resins, a method of forming a multi-layer coextrusion film using two or more kinds of resins, and further, using two or more kinds of resins. , Various resin films are produced by a method of mixing and forming a film before forming a film, and if necessary, for example, a uniaxial method using a tenter method, a tubular method, or the like. Alternatively, various resin films stretched in the biaxial direction can be used.

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

When one or more of the above various resins are used and the film is formed, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant property, slipperiness, release Various plastic compounding agents and additives can be added for the purpose of improving and modifying the shape, flame retardancy, antifungal property, electrical properties, strength, etc., and the amount of addition is extremely large. It can be arbitrarily added from a trace amount to several tens of percent depending on the purpose.

In the above, as general additives, for example, lubricants, cross-linking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments and the like can be used, and further. Can also be used as a modifying resin or the like.

In the present invention, the base film may be surface-treated in advance before forming the inorganic oxide-deposited film on the base film. This makes it possible to improve the adhesiveness with the inorganic oxide vapor deposition film. Similarly, surface treatment can be performed on the vapor-deposited layer to improve the adhesiveness with the gas barrier coating film. Such surface treatments include pretreatments such as corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, and oxidation treatment using chemicals or the like.

Further, a primer coating agent, an undercoating agent, a vapor deposition anchor coating agent, or the like can be arbitrarily applied to perform surface treatment. Examples of the coating agent include polyester resins, polyamide resins, polyurethane resins, epoxy resins, phenol resins, (meth) acrylic resins, polyvinyl acetate resins, and polyolefin resins such as polyethylene and polypropylene. A resin composition containing a resin or a copolymer or a modified resin thereof, a cellulose-based resin, or the like as a main component of the vehicle can be used.

Among such surface treatments, it is particularly preferable to perform corona treatment or plasma treatment. For example, as a plasma treatment, there is a plasma treatment in which surface modification is performed using plasma gas generated by ionizing a gas by arc discharge. In addition to the above, an inorganic gas such as oxygen gas, nitrogen gas, argon gas, and helium gas can be used as the plasma gas. For example, by performing the plasma treatment in-line, it is possible to remove water, dust and the like on the surface of the base film, and to enable surface treatment such as smoothing and activation of the surface. In addition, plasma treatment can be performed after vapor deposition to improve the adhesiveness. In the present invention, as the plasma treatment, it is preferable to perform the plasma discharge treatment in consideration of the plasma output, the type of plasma gas, the supply amount of plasma gas, the treatment time, and other conditions. Further, as a method of generating plasma, devices such as DC glow discharge, high frequency discharge, and microwave discharge can be used. In addition, plasma treatment can also be performed by the atmospheric pressure plasma treatment method.

(Inorganic oxide vapor deposition layer)
The thin-film vapor deposition layer constituting the barrier film according to the present invention is a thin-film deposition film formed by a chemical vapor deposition method (CVD method) or a physical vapor deposition method (PVD method). The barrier film includes a first inorganic oxide-deposited layer on one surface of the base film and a second inorganic oxide-deposited layer on the other surface of the base film. The first inorganic oxide-deposited layer in contact with the barrier coat layer mainly exhibits the barrier function as a barrier film, and the second inorganic oxide-deposited layer located on the outermost surface of the barrier film exhibits the barrier function. , It plays a role of improving the adhesiveness with the heat-bondable resin layer when forming the following laminated material.
Further, the barrier film may further include a third inorganic oxide vapor deposition layer between the primer layer and the barrier coat layer.

The first to third inorganic oxide vapor deposition layers are not particularly limited, but vapor deposition of oxides such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, and yttrium. A membrane can be used. In particular, the first to third inorganic oxide vapor-deposited layers are preferably a thin-film film of aluminum oxide or silicon oxide, and more preferably a thin-film film of aluminum oxide. The compositions of the first to third inorganic oxide vapor deposition layers may be the same or different.

Representation of the inorganic oxide, for _example, AlO X, MO _X (In the formula, M represents inorganic elements, the value of X is different ranges, respectively, by inorganic elements.) As such SiO _X is represented by To. In the present invention, from the viewpoint of interlayer adhesion strength and transparency, the value of X is preferably 0.5 to 2.0 when M is aluminum (Al), and X when M is silicon (Si). The value of is preferably 1-2.

As the first to third inorganic oxide vapor deposition layers, it is preferable to provide an aluminum oxide vapor deposition film by a physical vapor deposition method from the viewpoint of ease of handling as a vapor deposition material. The aluminum oxide vapor-deposited film formed by the physical vapor deposition method has excellent adhesion to the surface of the gas barrier coating film. Examples of the physical vapor deposition method include a physical vapor deposition method (PVD method) such as a vacuum deposition method, a sputtering method, an ion plating method, and an ion cluster beam method.

Specifically, a vacuum vapor deposition method in which aluminum or an oxide thereof is used as a raw material, which is heated to vaporize and vapor-deposited on one of the substrate films, for example, aluminum or an oxide thereof is used as a raw material. A vapor deposition film is formed by using an oxidation reaction vapor deposition method in which oxygen is introduced and oxidized to deposit on one of the base film, and a plasma-assisted oxidation reaction vapor deposition method in which the oxidation reaction is subsidized by plasma. Can be done. As the heating method of the thin-film 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.

When the first to third inorganic oxide vapor deposition layers are silicon oxide vapor deposition films, it is preferable to provide the silicon oxide vapor deposition film by the chemical vapor deposition method from the viewpoint of bending resistance and gas barrier properties. Examples of the chemical vapor deposition method include a chemical vapor deposition method such as a plasma chemical vapor deposition method, a low temperature plasma chemical vapor deposition method, a thermochemical vapor deposition method, and a photochemical vapor deposition method. CVD method) and the like. Specifically, on one surface of the base film, a monomer gas for vapor deposition such as an organic silicon compound is used as a raw material, an inert gas such as argon gas or helium gas is used as a carrier gas, and an oxygen supply gas is further used. As a result, a silicon oxide vapor deposition film can be formed by using a low temperature plasma chemical vapor deposition method using an oxygen gas or the like and using a low temperature plasma generator or the like. As the low temperature plasma generator, for example, a generator such as a high frequency plasma, a pulse wave plasma, or a microwave plasma can be used. It is preferable to use a generator by a high frequency plasma method in that a highly active and stable plasma can be obtained.

Examples of the monomer gas for vapor deposition of the organic silicon compound forming the silicon oxide vapor deposition film include 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, and hexamethyldisilane. Methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane Etc. can be used. Among these, it is particularly preferable to use 1,1,3,3-tetramethyldisiloxane or hexamethyldisiloxane as a raw material from the viewpoint of handleability, characteristics of the formed continuous film, and the like. In the above, as the inert gas, for example, argon gas, helium gas and the like can be used.

The vapor-deposited film of silicon oxide is mainly composed of silicon oxide, but further contains at least one kind of a compound composed of one kind or two or more kinds of elements such as carbon, hydrogen, silicon or oxygen by a chemical bond or the like. You may. For example, when the compound having a C—H bond, the compound having a Si—H bond, or the carbon unit is in the form of graphite, diamond, fullerene, etc., the raw material organic silicon compound or a derivative thereof can be further used. It may be contained due to chemical bonds or the like. For example, mention may be made of hydrocarbons having a CH ₃ site, SiH ₃ silyl, hydro silica such as SiH ₂ silylene, a hydroxyl derivative such as _SiH 2 OH silanol like. In addition to the above, the type, amount, and the like of the compound contained in the silicon oxide vapor deposition film can be changed by changing the conditions of the vapor deposition process.

The film thickness of the first inorganic oxide-deposited layer is preferably 5 to 15 nm, more preferably 7 to 12 nm. When the film thickness of the aluminum oxide vapor-deposited film of the first inorganic oxide-deposited layer is within the above range, it becomes easy to prevent the occurrence of cracks due to bending during box making while having suitable gas barrier properties.

The film thickness of the second and third inorganic oxide vapor deposition layers is preferably 1 to 50 nm, more preferably 5 to 20 nm. When the thickness of the second and third inorganic oxide vapor-deposited layers is within the above range, the barrier film of the present invention is used because it has suitable gas barrier properties and is excellent in adhesiveness to the following thermosetting resins. The laminated material provided has excellent interlayer adhesiveness.

(Barrier coat layer)
The barrier coat layer constituting the barrier film according to the present invention is a layer having a gas barrier property, and is preferably a coating film. Further, the barrier coat layer is preferably a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer.

The barrier coat layer can be formed by, for example, the following gas barrier coating film. The gas barrier coating film is a coating film that maintains gas barrier properties in a high temperature and high humidity environment, and the general formula R ¹ _n M (OR ² ) _m (however, in the formula, R ¹ and R ² have 1 to 1 carbon atoms. Represents an organic group of 8, 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). From a gas barrier composition containing at least one metal alkoxide and a water-soluble polymer, which is further subjected to polycondensation by the solgel method in the presence of a solgel method catalyst, acid, water, and an organic solvent. It is a coating film.

In the above general formula R ¹ _n M (OR ² ) _m , R ¹ is an alkyl group having 1 to 8 carbon atoms, preferably 1 to 5, more preferably 1 to 4, which may have a branch. 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 and the like. Can be mentioned.

In the above general formula R ¹ _n M (OR ² ) _m , R ² is an alkyl group having 1 to 8 carbon atoms which may have a branch, more preferably 1 to 5, and particularly preferably 1 to 4. Yes, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group and the like can be mentioned.
When a plurality of (OR ² ) are present in the same molecule, the (OR ² ) may be the same or different.

In the above general formula R ¹ _n M (OR ² ) _m , examples of the metal atom represented by 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 or more of a partial hydrolyzate of the alkoxide and a hydrolyzed condensate of the alkoxide can be used, and the alkoxide of the above alkoxide can be used. The partial hydrolyzate is not limited to one in which all of the alkoxy groups are hydrolyzed, and may be one in which one or more are hydrolyzed and a mixture thereof, and further, a condensate of hydrolysis. As the above, a dimer or more of the partially hydrolyzed alkoxide, specifically, a 2 to 6-mer may be used.

In the present invention, an alkoxysilane in which M is Si can be preferably used as the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m .
Suitable alkoxysilanes include, for example, tetramethoxysilane Si (OCH ₃ ) ₄ , tetraethoxysilane Si (OC ₂ H ₅ ) ₄ , tetrapropoxysilane Si (OC ₃ H ₇ ) ₄ , tetrabutoxysilane Si (OC _4). 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 , Dimethyldi Examples thereof include ethoxysilane (CH ₃ ) ₂ Si (OC ₂ H ₅ ) ₂ . Further, in the present invention, polycondensation polymers of these alkoxysilanes can also be used, and specifically, for example, polytetramethoxysilane, polytetraemethoxysilane and the like can be used.

In the present invention, as the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , a zirconium alkoxide in which M is Zr can also be preferably used.
Suitable zirconium alkoxides include, for example, tetramethoxyzirconium Zr (OCH ₃ ) ₄ , tetraethoxyzirconium Zr (OC ₂ H ₅ ) ₄ , tetra ipropoxyzirconium Zr (iso-OC ₃ H ₇ ) ₄ , tetran butoxyzirconium. Examples thereof include Zr (OC ₄ H ₉ ) ₄ .

Further, as the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , a titanium alkoxide in which M is Ti can also be preferably used.
Suitable titanium alkoxides include, for example, tetramethoxytitanium Ti (OCH ₃ ) ₄ , tetraethoxytitanium Ti (OC ₂ H ₅ ) ₄ , tetraisopropoxytitanium Ti (iso-OC ₃ H ₇ ) ₄ , tetran butoxytitanium. Ti (OC ₄ H ₉ ) _{4 and the} like can be mentioned.

Further, as the alkoxide represented by the above 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 such as tetramethoxysilane aluminum Al _{(OCH 3) 4,} tetraethoxy aluminum _{Al (OC 2 H 5) 4} , tetraisopropoxy aluminum _{Al (iso-OC 3 H 7} ) 4, tetra-n-butoxy aluminum Al (OC ₄ H ₉ ) _{4 and the} like can be mentioned.

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

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

As the polyvinyl alcohol-based resin, one obtained by saponifying polyvinyl acetate can generally be used. The polyvinyl alcohol-based resin may be a partially saponified polyvinyl alcohol-based resin in which several tens of percent of acetate groups remain, a completely saponified polyvinyl alcohol in which no acetate group remains, or a modified polyvinyl alcohol-based resin in which OH groups are modified. Well, it is not particularly limited.

As the ethylene-vinyl alcohol copolymer, a saponified product of a copolymer of ethylene and vinyl acetate, that is, a copolymer obtained by saponifying an ethylene-vinyl acetate random copolymer can be used. For example, it includes, and is not particularly limited, from a partially saponified product in which several tens of mol% of acetic acid groups remain to a completely saponified product in which only a few mol% of acetic acid groups remain or no acetic acid groups remain.
However, from the viewpoint of gas barrier properties, the degree of saponification is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. The content of the repeating unit derived from ethylene in the above ethylene / vinyl alcohol copolymer (hereinafter, also referred to as “ethylene content”) is usually 0 to 50 mol%, preferably 20 to 45 mol%. Is preferable.

Further, a silane coupling material may be added to the barrier coat layer. For example, a silane coupling material having a reactive group such as an alkoxy group such as a methoxy group or an ethoxy group, an acetoxy group, an amino group or an epoxy group can be used.

Further, as the organic solvent used in the above gas barrier 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 state of being dissolved in a coating liquid containing the alkoxide, a silane coupling agent, or the like, and is preferably handled from the above organic solvents. It can be selected as appropriate. For example, when a polyvinyl alcohol-based resin and an ethylene / vinyl alcohol copolymer are used in combination, it is preferable to use n-butanol.

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

Next, the gas barrier composition is applied onto the first inorganic oxide vapor deposition layer. As a method of applying the gas barrier composition, for example, a roll coating such as a gravure roll coater, a spray coating, a spin coating, a dipping, a brush, a bar code, an applicator or the like can be applied once or a plurality of times. A coating film having a dry film thickness of 0.01 to 30 μm, preferably about 0.1 to 10 μm can be formed.

Next, the film coated with the gas barrier composition is heated and dried at a temperature of 20 ° C. to 200 ° C. and a temperature equal to or lower than the melting point of the vapor-deposited film, preferably in the temperature range of 50 ° C. to 180 ° C. for 10 seconds to 10 minutes. .. As a result, polycondensation is carried out and a barrier coat layer can be formed. Further, the gas barrier composition is applied over the first inorganic oxide vapor deposition layer, and two or more coating films are laminated to be 20 ° C. to 200 ° C. and lower than the melting point of the resin base material. It may be heat-dried at a temperature for 10 seconds to 10 minutes to form a composite polymer layer in which two or more gas barrier coating films are laminated. As described above, one or two or more barrier coat layers made of the gas barrier composition can be formed.

(Primer layer)
The primer layer constituting the barrier film according to the present invention contains a polyolefin polymer, and the polyolefin polymer contains 0.01 of unsaturated carboxylic acid and / or a component derived from its acid anhydride as a copolymerization component. Includes% by mass or more and 5% by mass or less.
Since the primer layer contains the polyolefin polymer, the primer layer has appropriate elasticity or flexibility, so that the influence on the first inorganic vapor-deposited layer due to pressing during cutting or box making of a paper container is reduced. It is possible to suppress the deterioration of the gas barrier property.

The polyolefin polymer contains an olefin component and a component derived from an unsaturated carboxylic acid and / or an acid anhydride thereof as a copolymerization component.

Examples of the olefin component include ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, 1-octene, butadiene and isoprene. The polyolefin polymer can contain one or more of these as a copolymer component.
Among these, it is preferable to contain at least one of ethylene and propylene.

The content of the olefin component in the polyolefin polymer is preferably 50% by mass or more and 95% by mass or less, and more preferably 55% by mass or more and 94.5% by mass or less. As a result, the adhesion to the barrier coat layer can be improved, and the aqueous dispersibility of the polyolefin polymer can be improved.

Examples of the unsaturated carboxylic acid contained in the polyolefin polymer include (meth) acrylic acid, maleic acid, itaconic acid, fumaric acid and crotonic acid.
The polyolefin polymer can contain two or more kinds of polyolefin polymers and acid anhydrides thereof.

As long as the characteristics of the present invention are not impaired, the polyolefin polymer may contain components (other components) other than the olefin component and the unsaturated carboxylic acid component.
Other components include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, dimethyl maleate, diethyl maleate, dibutyl maleate, methyl vinyl ether, ethyl vinyl ether, vinyl formate, etc. Examples thereof include vinyl acetate and vinyl propionate.

In the polyolefin polymer, the copolymerization form of each component is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. Among these, random copolymerization is performed from the viewpoint of easiness of polymerization. Is preferable.

The acid value of the polyolefin polymer is preferably 5 mgKOH / g or more and 50 mgKOH / g or less, and more preferably 7 mgKOH / g or more and 40 mgKOH / g or less. Thereby, the aqueous dispersibility of the polyolefin polymer can be improved.

The weight average molecular weight of the polyolefin polymer is preferably 20,000 or more and 100,000 or less, and more preferably 25,000 or more and 70,000 or less.
By setting the weight average molecular weight of the polyolefin polymer to 20000 or more, the adhesion to the barrier coat layer can be improved. Further, by setting the weight average molecular weight of the polyolefin polymer to 100,000 or less, the aqueous dispersibility of the polyolefin polymer can be improved.
In the present invention, the weight average molecular weight is a value obtained in terms of polystyrene by gel permeation chromatography (GPC) in accordance with JIS K 7252-1 (issued in 2008).

The melting point of the polyolefin polymer is preferably 70 ° C. or higher and 200 ° C. or lower, and more preferably 80 ° C. or higher and 180 ° C. or lower. By setting the melting point of the polyolefin polymer to 70 ° C. or higher, the weather resistance of the primer layer can be improved. Further, by setting the melting point of the polyolefin polymer to 200 ° C. or lower, the aqueous dispersibility of the polyolefin polymer can be improved.

The content of the polyolefin polymer in the primer layer is preferably 50% by mass or more and 99% by mass or less, and more preferably 60% by mass or more and 95% by mass or less.

The primer layer may contain a resin (other resin) other than the polyolefin polymer as long as the characteristics of the present invention are not impaired. Examples of other resins include polyolefin resins, polyester resins, polyamide resins, vinyl resins, polyurethane resins, silicone resins, epoxy resins, phenol resins and the like.
The content of the other resin in the primer layer is preferably 10% by mass or less, and more preferably 5% by mass or less.

To the extent that the properties of the present invention are not impaired, the primer layer comprises pigments such as titanium oxide, zinc oxide and carbon black, dyes such as disperse dyes, acidic dyes and cationic dyes, antioxidants, lubricants, colorants and stabilizers. , Wetting agents, thickeners, coagulants, gelling agents, antisettling agents, softening agents, plasticizing agents, leveling agents, ultraviolet absorbers, flame retardants and other additives can be included.

The primer layer is preferably formed by using an aqueous dispersion in which the polyolefin polymer is dispersed so that the number average particle size is 1 μm or less. Thereby, the film-forming property can be improved.
From the viewpoint of film forming property, the number average particle size of the polyolefin polymer is more preferably 0.005 μm or more and 0.5 μm or less.
In the present invention, the number average particle size is measured by a dynamic light scattering method. More specifically, it can be measured by using the Microtrack particle size distribution meter UPA150 manufactured by Nikkiso Co., Ltd.

The aqueous dispersion preferably contains a basic compound from the viewpoint of dispersion stability. Examples of the basic compound include ammonia, triethylamine, N, N-dimethylethanolamine, isopropropylamine, aminoethanol, dimethylaminoethanol, ethylamine, diethylamine, isobutylamine, pyrrole, pyridine and the like.

The aqueous dispersion preferably contains an organic solvent from the viewpoint of the aqueous dispersibility of the polyolefin polymer. Examples of the organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, amyl alcohol, hexanol, cyclohexanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, ethylene glycol monoethyl ether, and the like. Ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, tetrahydrofuran, dioxane, ethyl acetate, -n-butyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, diethyl carbonate, ethyl acetoacetate, and Examples thereof include trimethylglycerin. The aqueous dispersion can contain two or more of these organic solvents.

The content of the organic solvent in the aqueous dispersion is preferably 3% by mass or more and 35% by mass or less. By setting the content of the organic solvent in the aqueous dispersion to 3% by mass or more, the aqueous dispersibility of the polyolefin polymer can be improved. Further, by setting the content of the organic solvent in the aqueous dispersion to 35% by mass or less, the environmental load in the production of the barrier film can be reduced.

The aqueous dispersion preferably does not substantially contain a non-volatile aqueous auxiliary such as an emulsifier or a modified wax, and specifically, it is preferably 5% by mass or less, and preferably 3% by mass or less. More preferably, it is 0.1% by mass or less.

As the aqueous dispersion, commercially available ones may be used, and examples thereof include Arrow Base SB-1200, SD-1200, SE-1200 and SD-1205J2 manufactured by Unitika Ltd.

The thickness of the primer layer is preferably 0.05 μm or more and 3 μm or less, and more preferably 0.1 μm or more and 1 μm or less. By setting the thickness of the primer layer to 0.05 μm or more, the adhesion to the substrate and the thermosetting resin layer is improved. Further, by setting the thickness of the primer layer to 3 μm or less, poor drying is prevented.

The primer layer is obtained by applying the above-mentioned aqueous dispersion to a conventionally known coating method, for example, a gravure roll coating method, a reverse roll coating method, a wire bar coating method, a lip coating method, an air knife coating method, a curtain flow coating method, a spray coating method, or the like. It can be done by using.

<Laminate material>
The laminated material of the present invention includes an outermost layer, a paper base material layer, a first thermosetting resin layer, a barrier layer made of the barrier film, a second thermosetting resin layer, and an innermost layer. And are prepared in this order.
Since the laminated material of the present invention has such a layer structure, it has excellent interlayer adhesiveness between the first thermosetting resin layer and the barrier layer and between the barrier layer and the second thermosetting resin layer. Moreover, it has excellent gas barrier properties, and the gas barrier properties do not easily deteriorate even after cutting or making a paper container. Therefore, the laminate of the present invention can be suitably used as a laminate for various containers and the like that require gas barrier properties and strong adhesiveness, and can be suitably used, for example, as a laminate for paper containers.

The adhesive strength required for the barrier film and the thermosetting resin in the laminated material for paper containers is 1.5 N / 15 mm or more, preferably 2.0 N / 15 mm or more on the paper base material side, and is on the content side. Is 3.0 N / 15 mm or more, preferably 3.5 N / 15 mm or more. With this adhesive strength, the barrier film of the laminated material can be peeled off from the paper base material or resin layer by punching the laminated material for paper containers into a blank plate or embossing ruled line molding for bending, or roll-shaped paper. It is possible to reduce peeling in processes such as bending, embossing, and cutting in a system for in-line box making from a laminated material for a container.

The layer structure of the laminated material for a paper container of the present invention will be described with reference to the drawings. The laminated material 20 for a paper container shown in FIG. 2 includes an outermost layer 22, a paper base material layer 21, a resin layer 23, a first heat-sealing resin layer 24, a barrier film (barrier layer) 10, and the like. The second heat-sealing resin layer 25, the resin layer 26, and the innermost layer 27 are provided in this order. The primer layer 12 of the barrier film 10 is in contact with the first heat-sealing resin layer 24, and the second inorganic oxide vapor deposition layer 14 of the barrier film 10 is in contact with the second heat-sealing resin layer 25. Alternatively, the primer layer 12 of the barrier film 10 is in contact with the second heat-sealing resin layer 25, and the second inorganic oxide vapor deposition layer 14 of the barrier film 10 is the second heat-sealing resin layer. It may be configured to be in contact with 24. Hereinafter, each layer constituting the laminated material for a paper container of the present invention will be described.

(Outermost layer)
In the laminated material for paper containers of the present invention, a thermoplastic resin can be used as the outermost layer. Specifically, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, ethylene-α / olefin copolymer polymerized using a metallocene catalyst, polypropylene, ethylene. -Vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer , Methylpentene polymer, polybutene polymer, acid-modified polyolefin resin obtained by modifying a polyolefin resin such as polyethylene or polypropylene with an unsaturated carboxylic acid such as acrylic acid, methacrylate, maleic acid, maleic anhydride, fumaric acid, and itaconic acid, poly Resins such as vinyl acetate-based resin, poly (meth) acrylic-based resin, and polyvinyl chloride-based resin can be used.

The outermost layer can be formed by melt-extruding the above-mentioned one or more types of thermoplastic resins onto a paper substrate layer via an anchor coat layer or the like, if desired, using an extruder or the like. Alternatively, a film or sheet of the resin is produced in advance using the above-mentioned one or more types of thermoplastic resin, and the produced film or sheet is placed on the paper base material layer via an adhesive layer for laminating or the like. The outermost layer can also be formed by laminating with a dry laminate.

The thickness of the outermost layer is preferably about 5 to 200 μm, more preferably about 10 to 100 μm.

(Paper substrate layer)
In the laminated material for paper containers of the present invention, any paper base material can be used as the paper base material layer depending on the intended use. In particular, in order to make a box and use it as a liquid paper container, it is necessary to use a paper base material having sufficiently high moldability, bending resistance, rigidity, waist and strength. Examples of such a paper base material include a strong-sized bleached or unbleached paper base material, or various paper base materials such as pure white roll paper, kraft paper, paperboard, and processed paper, and have a basis weight. about 80~600g / ^{m 2} about things, preferably, it can be preferably used of about basis weight of about 100~450g / ^{m 2.}

Further, the paper base material of the liquid paper container needs to have a certain thickness so as to be able to impart sufficient strength to contain the liquid. Since the barrier film for paper containers of the present invention can be adhered to such a thick paper base material with high interlayer adhesive strength, the paper container made of this can be used for various packaging for storing liquids. Can be suitably used for. In addition, it can be in a self-supporting form such as a cube.

As a method of laminating the paper base material layer on the first thermosetting resin layer, it may be laminated by extruding the above-mentioned one or more types of thermoplastic resins, or via an adhesive or the like. May be dry laminated.

(Thermosetting resin layer)
In the laminated material for paper containers of the present invention, as the thermosetting resin constituting the thermosetting resin layer, an ethylene polymer having a carboxyl group or an acid anhydride group in the molecule is preferably used. The ethylene-based polymer can exhibit excellent interlayer adhesiveness by being in contact with the primer layer and the second and third inorganic oxide vapor deposition layers of the barrier film.

Examples of the above-mentioned ethylene-based polymer include a copolymer of ethylene and an unsaturated carboxylic acid or an anhydride thereof. The unsaturated carboxylic acid or its anhydride is a compound having at least one carboxyl group or an acid anhydride group in the molecule, and specifically, crotonic acid, methacrylic acid, maleic acid, maleic anhydride. , Itaconic acid, itaconic anhydride, fumaric acid, crotonic acid and the like. A copolymer of ethylene with acrylic acid or methacrylic acid is particularly preferably used in order to improve the adhesiveness of the inorganic oxide to the vapor-deposited film.

In the above ethylene-based copolymer, the ratio of ethylene to unsaturated carboxylic acid or its anhydride, melt flow rate (MFR), etc. are appropriately determined by those skilled in the art according to the properties of the paper substrate to be used. can do. Generally, in order to enhance the adhesiveness between the thermosetting resin layer and the barrier film, it is preferable that the proportion of unsaturated carboxylic acid or its anhydride in the ethylene-based copolymer is high. In the present invention, the ratio of unsaturated carboxylic acid or its anhydride in the ethylene-based copolymer is 3% to 9 by adhering the thermosetting resin layer via the inorganic oxide vapor deposition layer on the barrier film. Sufficient adhesive strength can be achieved even at a low ratio of about%.

The thickness of the thermosetting resin layer is preferably about 1 to 50 μm, and more preferably about 3 to 20 μm from the viewpoint of film forming property and adhesiveness.

(Innermost layer)
In the laminated material for paper containers of the present invention, a resin having a heat-sealing property can be used as the innermost layer. Specifically, the same resin as the outermost layer described above can be used.

The innermost layer can be provided on the surface of the second thermosetting resin layer by melt-extruding the above-mentioned one or more types of thermoplastic resins with an extruder or the like. Alternatively, a film or sheet of the above resin is manufactured in advance using the above-mentioned film or sheet of one or more types of thermoplastic resin, and the manufactured film or sheet is passed through an adhesive layer for laminating or the like. A dry laminate may be laminated on the surface on the side of the second thermosetting resin layer. If desired, various surface treatments such as applying an anchor coating agent in advance may be applied to the laminated surface.
Further, one or more resin layers may be provided between the innermost layer and the second thermosetting resin layer by extruding the above-mentioned one or more types of thermoplastic resin.

In order to form the innermost layer of the present invention, low density polyethylene can be preferably used, and particularly preferably, linear (linear) low density polyethylene polymerized using a metallocene catalyst can be used. it can. Since these resins exhibit low-temperature sealing properties, it is possible to prevent cracks and the like from being applied to the thin-film vapor deposition film of the inner layer during laminating or box making. Further, it has an advantage that the occurrence of pinholes can be prevented and sealing failure, liquid leakage and the like can be avoided. In order to obtain the desired properties, the above resin may be blended with another resin and used. In addition, various additives such as antioxidants, ultraviolet absorbers, antistatic agents, antiblocking agents, lubricants (fatty acid amides, etc.), flame retardants, inorganic or organic fillers, dyes, pigments, etc. are arbitrarily added. Can be used.

The film thickness of the innermost layer is preferably about 10 μm to 300 μm, and more preferably about 20 μm to 100 μm in order to prevent sealing defects.

<Paper container>
The paper container of the present invention is made by manufacturing the above-mentioned laminate material for paper containers, and can be particularly preferably used as a liquid paper container.

The paper container may be of any type, for example, a brick type, a flat type or a Goebel top type. In addition, the shape can be any of a square container, a cylindrical paper can such as a round shape, and the like. The paper container of the present invention can be filled and packaged with various articles such as various foods and drinks, chemicals such as adhesives and adhesives, and miscellaneous goods such as cosmetics and pharmaceuticals. In particular, it is useful as a liquid paper container for filling and packaging juices such as sake and fruit juice beverages, liquid seasonings such as mineral water, soy sauce, sauces and soups, and various liquid foods and drinks such as curry, stew and soup. It is a thing.

The paper container has a volume of 200 mL, and the oxygen permeability measured in an environment of a temperature of 23 ° C. and a humidity of 50 RH% is preferably 0.15 cc / pkg · day or less, more preferably 0.1 cc / pkg · day. It is less than or equal to, more preferably 0.03 cc / pkg · day or less. If the oxygen permeability of the paper container satisfies the above numerical range, the adverse effect on the contents of the paper container can be suppressed.

The volume of the paper container is 200 mL, and the water vapor permeability from the inside of the container to the outside of the container measured in an environment of 40 ° C. is preferably 0.3 g / pkg · day or less, more preferably 0.1 g / pkg. -Day or less, more preferably 0.05 g / pkg-day or less. If the water vapor permeability of the paper container satisfies the above numerical range, it has a suitable water vapor barrier property, so that an adverse effect on the contents of the paper container can be suppressed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

<Manufacturing of barrier films and laminated materials>
[Example 1]
As a base film, a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared. Using a continuous vapor deposition film deposition apparatus that separates the pretreatment section and the film formation section in which the plasma pretreatment device is arranged on the surface forming the vapor deposition layer of the PET film, the plasma supply nozzle in the pretreatment section under the following plasma conditions. Plasma was introduced from the plasma and subjected to plasma pretreatment at a transport speed of 600 m / min. Then, in the film-forming section that was continuously transported, the reactive resistance heating method was used as a heating means for the vacuum vapor deposition method on the plasma-treated surface under the following conditions. , An aluminum oxide vapor deposition film (first inorganic oxide vapor deposition layer) having a thickness of 10.5 nm was formed.
(Plasma pretreatment conditions)
・ Plasma intensity: 150 W ・ sec / m ²
-Plasma forming gas: Argon 1200 (sccm), Oxygen 3000 (sccm)
-Magnetic forming means: 1000 gauss permanent magnet-Pretreatment drum-plasma supply nozzle applied voltage: 340V
-Vacuum degree of pretreatment section: 3.8 Pa
(Aluminum oxide film formation conditions)
・ Vacuum degree: 8.1 × 10 ^-2 Pa

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

Next, the gas barrier composition prepared above was coated on the aluminum oxide vapor-deposited film of the PET film by the direct gravure method. Then, it was heat-treated at 140 ° C. for 60 seconds to form a gas barrier coating film having a thickness of 0.3 μm (dry operation state).

Next, Arrowbase SD-1205J2 (manufactured by Unitika Ltd.) was applied onto the gas barrier coating film and dried to form a primer layer having a thickness of 0.5 μm.

Subsequently, on the other surface of the PET film, a continuous vapor deposition film deposition apparatus in which the pretreatment section and the film formation section in which the plasma pretreatment device is arranged is separated is used, and the plasma is generated in the pretreatment section under the above-mentioned plasma conditions. Plasma is introduced from the supply nozzle, plasma pretreatment is performed at a transport speed of 600 m / min, and then, in the film formation section that is continuously transported, a reactive resistance heating method is used as a heating means for the vacuum deposition method on the plasma treated surface. A barrier film 1 (layer structure: "primer layer / barrier coat layer / first inorganic oxide vapor deposition layer / base film" is formed by forming an aluminum oxide vapor deposition film (second inorganic oxide vapor deposition layer) having a thickness of 8 nm. / Second inorganic oxide vapor deposition layer ") was obtained.

After corona treatment (2 kW) was applied to the surface of the obtained barrier film 1 on the primer layer side, an ethylene-methacrylic acid copolymer (EMAA, extrusion film thickness: 15 μm) was melt-extruded to obtain a first thermosetting. A adhesive resin layer was formed. Further, an ethylene-methacrylic acid copolymer (EMAA, extrusion film thickness: 15 μm) is melt-extruded onto the surface of the barrier film 1 on the side of the second inorganic oxide vapor deposition layer to form a second thermosetting resin layer. Was formed to obtain a laminated intermediate.

Subsequently, the second thermosetting resin layer surface of the laminated intermediate and the ethylene-α / olefin copolymer film (m-PEF) (thickness 15 μm) to be the innermost layer are laminated by a sandwich laminating method. Laminated through low density polyethylene (extrusion temperature: 300 ° C., extrusion film thickness: 15 μm).

Further, after corona discharge treatment is applied to one surface of the paper substrate (thickness 200 g / m), a low density polyethylene resin (extrusion temperature: 300 ° C., extrusion film thickness: 15 μm) is applied to the corona discharge treated surface. The outermost layer was formed by melt extrusion. Subsequently, the first thermosetting resin layer surface of the laminated intermediate and the other surface of the paper base material are laminated via a low density polyethylene (extruded film thickness: 15 μm) by a sandwich laminating method. , Laminated material 1 (Layer structure: "Outermost layer / Paper substrate layer / Resin layer / First thermosetting resin layer / Barrier film 1 (Primer primer layer / Barrier coat layer / First inorganic oxide vapor deposition layer) / Base film / Second inorganic oxide vapor deposition layer) / Second thermosetting resin layer / Resin layer / Innermost layer ") was obtained.

[Example 2]
A laminated material 2 was obtained in the same manner as in Example 1 except that the first thermosetting resin layer was formed on the surface of the barrier film 1 on the primer layer side without corona treatment (2 kW).

[Example 3]
As a base film, a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared. Subsequently, the PET film was attached to a delivery roll of a plasma chemical vapor deposition apparatus, and then, hexamethyldisiloxane, which is a raw material, was introduced onto one surface of the film, and the amount of introduced gas was hexamethyldisiloxane: oxygen gas: Helium = 1.0: 1.5: 1.0 (unit: slm), vacuum degree 2-6 × ^10-6 mBar in vacuum chamber, vacuum degree 2-5 × 10 ^-3 mBar in vapor deposition chamber, cooling -The electrode drum was supplied with a power supply of 10 kW to form a silicon oxide vapor deposition film (first inorganic oxide vapor deposition layer) having a thickness of 10 nm. A barrier film 2 was obtained in the same manner as in Example 1 except for the formation of the first inorganic oxide vapor deposition layer.

Subsequently, the laminated material 3 was obtained in the same manner as in Example 1 except that the barrier film 1 was changed to the barrier film 2.

[Comparative Example 1]
An aluminum oxide vapor deposition film and a barrier coat layer are formed on one surface of the base film in the same manner as in Example 1, and the barrier film 3 (layer structure: "barrier coat layer / first inorganic oxide vapor deposition layer"). / Base film ") was obtained.

Next, after corona treatment (2 kW) is applied to the surface of the barrier film 3 on the barrier coat layer side, a first thermosetting resin layer is formed in the same manner as in Example 1, and the other side of the barrier film 3 is formed. After corona treatment (2 kW) was applied to the surface of the film, a second thermosetting resin layer was formed in the same manner as in Example 1 to obtain a laminated intermediate. Subsequently, using the laminated intermediate, a laminated material 4 was obtained in the same manner as in Example 1.

[Comparative Example 2]
On the gas barrier coating film of the film produced in Example 1, a continuous vapor deposition film film forming apparatus was used in which the pretreatment section in which the plasma pretreatment device was arranged and the film forming section were separated, and the following plasma conditions were applied in the pretreatment section. Introducing plasma from the plasma supply nozzle, performing plasma pretreatment at a transport speed of 600 m / min, and then using a reactive resistance heating method as a heating means for the vacuum deposition method on the plasma-treated surface in the film-forming section that was continuously transported. To form an aluminum oxide vapor-deposited film (third inorganic oxide-deposited layer) having a thickness of 8 nm, the barrier film 4 (layer structure: "third inorganic oxide-deposited layer / barrier coat layer / first inorganic" Oxide-deposited layer / base film ") was obtained.

Subsequently, a laminated material 5 was obtained in the same manner as in Comparative Example 1 except that the barrier film 1 was changed to the barrier film 4.

[Comparative Example 3]
As a base film, a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was prepared. Subsequently, the PET film was attached to a delivery roll of a plasma chemical vapor deposition apparatus, and then, hexamethyldisiloxane, which is a raw material, was introduced onto one surface of the film, and the amount of introduced gas was hexamethyldisiloxane: oxygen gas: Helium = 1.0: 1.5: 1.0 (unit: slm), vacuum degree 2-6 × ^10-6 mBar in vacuum chamber, vacuum degree 2-5 × 10 ^-3 mBar in vapor deposition chamber, cooling -The electrode drum was supplied with a power supply of 10 kW to form a silicon oxide vapor deposition film (first inorganic oxide vapor deposition layer) having a thickness of 10 nm.

Subsequently, in the same manner as in Comparative Example 2, a barrier coat layer and a third inorganic oxide vapor deposition layer were formed on the first inorganic oxide vapor deposition layer, and the barrier film 5 (layer structure: "third An inorganic oxide-deposited layer / barrier coat layer / first inorganic oxide-deposited layer / base film ") was obtained.

Subsequently, a laminated material 6 was obtained in the same manner as in Comparative Example 1 except that the barrier film 1 was changed to the barrier film 5.

[Comparative Example 4]
Using a continuous thin-film deposition film deposition apparatus that separates the pretreatment section and the film formation section in which the plasma pretreatment device is arranged on the base film of the barrier film 4, the plasma supply nozzle in the pretreatment section under the following plasma conditions. Plasma was introduced from the surface, subjected to plasma pretreatment at a transport speed of 600 m / min, and then, in the film-forming section that was continuously transported, the thickness was increased by a reactive resistance heating method as a heating means of the vacuum deposition method on the plasma treated surface. A barrier film 6 (layer structure: "third inorganic oxide vapor deposition layer / barrier coat layer / first inorganic oxide vapor deposition layer" is formed by forming an 8 nm aluminum oxide vapor deposition film (second inorganic oxide vapor deposition layer). / Base film / Second inorganic oxide vapor deposition layer ") was obtained.

Subsequently, a laminated material 7 was obtained in the same manner as in Comparative Example 1 except that the barrier film 1 was changed to the barrier film 6.

Table 2 shows the layer structure of the barrier films produced in the above Examples and Comparative Examples.

<Performance evaluation of barrier film and laminated material>
The following measurements were performed on the barrier films, laminated intermediates, laminated materials, and paper containers using the barrier films, laminated intermediates, and laminated materials produced in Examples 1 to 3 and Comparative Examples 1 to 4 described above.

(Measurement of interlayer adhesion strength)
The laminated intermediates provided with the first and second thermosetting resin layers on both sides in the above Examples and Comparative Examples were peeled off using a tensile tester (Tencilon universal tester RTC1310A, manufactured by Orientec). A T-shaped peeling test was performed at a speed of 50 mm / min, and the peeling strength (N / 15 mm) at the interface between the first thermosetting resin layer and the barrier film was measured. Similarly, the peel strength (N / 15 mm) at the interface between the barrier film and the second thermosetting resin layer was measured. The measurement results are shown in Table 3. If the peel strength is 3 or more, there is no problem in practical use.

(Measurement of water vapor permeability)
The barrier films produced in Examples 1 to 3 and Comparative Examples 1 to 4 above have a water vapor permeability in accordance with JIS K 7129 using a measuring machine (model name: OXTRAN) manufactured by MOCON, USA. Was measured. As a result, the water vapor permeability of the barrier films produced in Examples 1 to 4 and Comparative Examples 1 to 4 was 1.0 g / m ² · day or less.

(Measurement of oxygen permeability)
For the barrier films produced in Examples 1 to 3 and Comparative Examples 1 to 4 above, a measuring machine (model name: OXTRAN) manufactured by MOCON, USA, was used under the conditions of a temperature of 23 ° C. and a humidity of 90% RH. The oxygen permeability (cc / m ² · day) was measured according to JIS K 7126. The measurement results are shown in Table 3.

The laminates produced in Examples 1 to 3 and Comparative Examples 1 to 4 above are cut into sheets having a predetermined shape, and then under the conditions of a temperature of 23 ° C. and a humidity of 90% RH, MOCON, USA. Oxygen permeability (cc / m ² · day) was measured according to JIS K 7126 using a measuring machine (model name: OXTRAN) manufactured by the same company. The measurement results are shown in Table 3.

The laminates produced in Examples 1 to 3 and Comparative Examples 1 to 4 described above were boxed to produce a brick-type paper container having a size of 200 mL. Regarding the obtained paper container, in an environment of temperature 23 ° C. and humidity 50% RH, a sealing jig to be connected to a measuring machine (model name: OXTRAN) manufactured by MOCON in the United States was attached and inside the paper container. The penetrating oxygen permeability (cc / pkg · day) was measured. The measurement results are shown in Table 3.

10 Barrier film 11 Base film 12 Primer layer 13 First inorganic oxide vapor deposition layer 14 Second inorganic oxide vapor deposition layer 15 Barrier coat layer 20 Laminate material for paper containers 21 Paper base layer 22 Outermost layer 23 Resin layer 24 1st heat-sealing resin layer 25 2nd heat-sealing resin layer 26 Resin layer 27 Innermost layer

Claims (13)

It ’s a barrier film,
A primer layer, a barrier coat layer, a first inorganic oxide vapor deposition layer, a base film, and a second inorganic oxide vapor deposition layer are provided in this order, and the primer layer contains a polyolefin polymer.
The polyolefin polymer contains 0.01% by mass or more and 5% by mass or less of a component derived from unsaturated carboxylic acid and / or its anhydride.
A barrier film in which the barrier coat layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer. The barrier film according to claim 1, wherein the primer layer is formed by using an aqueous dispersion in which the polyolefin polymer is dispersed so that the number average particle size is 1 μm or less. The barrier film according to claim 1 or 2, wherein the content of the polyolefin polymer in the primer layer is 50% by mass or more and 99% by mass or less. The barrier film according to any one of claims 1 to 3, wherein the thickness of the primer layer is 0.05 μm or more and 3 μm or less. The barrier film according to any one of claims 1 to 4, wherein the first inorganic oxide-deposited layer is an aluminum oxide-deposited film or a silicon oxide-deposited film. The barrier film according to any one of claims 1 to 5, wherein the second inorganic oxide-deposited layer is an aluminum oxide-deposited film or a silicon oxide-deposited film. The barrier film according to any one of claims 1 to 6, which is used for a paper container. Laminated material for paper containers
The outermost layer, the paper base material layer, the first thermosetting resin layer, the barrier layer, the second thermosetting resin layer, and the innermost layer are provided in this order, and the barrier layer is claimed. A laminated material for a paper container, which comprises the barrier film according to any one of 1 to 7. The laminate for a paper container according to claim 8, wherein the thermosetting resin constituting the thermosetting resin layer is an ethylene polymer having a carboxyl group or an acid anhydride group in the molecule. The primer layer of the barrier film is in contact with the first thermosetting resin layer,
The laminate for paper containers according to claim 8 or 9, wherein the second inorganic oxide-deposited layer of the barrier film is in contact with the second thermosetting resin layer. The primer layer of the barrier film is in contact with the second thermosetting resin layer,
The laminate for a paper container according to claim 8 or 9, wherein the second inorganic oxide-deposited layer of the barrier film is in contact with the first thermosetting resin layer. 8. A resin layer is further provided between the paper base material layer and the first thermosetting resin layer and / or between the second thermosetting resin layer and the innermost layer. The laminated material for a paper container according to any one of 1 to 11. A paper container obtained by manufacturing a laminated material for a paper container according to any one of claims 8 to 12.