JP2020055302A - Packaging material for paper container and liquid-storing paper container - Google Patents

Abstract

To prevent a transparent vapor deposition layer containing an aluminum oxide from being deteriorated in characteristics thereof by heat.SOLUTION: A packaging material for a paper container at least includes an outer thermoplastic resin layer, a paper substrate layer, an adhesive resin layer, a vapor deposition film, an adhesive layer and an inner thermoplastic resin layer, sequentially from outside to inside. The vapor deposition film includes an oriented plastic film, a transparent vapor deposition layer disposed on a surface inside the oriented plastic film and containing an aluminum oxide, and a gas barrier coating film disposed on the transparent vapor deposition layer. The oriented plastic film of the vapor deposition film contains a biomass-derived polyester.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid paper container for storing a liquid and a packaging material for forming the liquid paper container.

  Polyester is widely used in various industrial applications because it is excellent in mechanical properties, chemical stability, heat resistance, transparency, etc. and inexpensive. Polyester is obtained by polycondensing a diol unit and a dicarboxylic acid unit. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is obtained by subjecting ethylene glycol and terephthalic acid to esterification reaction of these materials. After the polycondensation reaction. These raw materials are produced from petroleum, which is a fossil resource. For example, ethylene glycol is produced industrially from ethylene, and terephthalic acid is produced industrially from xylene.

  In recent years, with the increasing demand for the establishment of a recycling-based society, in the materials field as well, there has been a desire to break away from fossil fuels as well as energy, and the use of biomass has attracted attention. Biomass is an organic compound that is photosynthesized from carbon dioxide and water, and is a so-called carbon-neutral renewable energy that is converted into carbon dioxide and water again by using it. Recently, biomass plastics using these biomass as raw materials have been rapidly commercialized, and attempts have been made to produce polyesters, which are general-purpose polymer materials, from these biomass raw materials.

  As a polyester using a biomass raw material, a polyester composed of isosorbide, terephthalic acid, and ethylene glycol, which are one of the biomass raw materials, is known. For example, Patent Literature 1 proposes that a liquid paper container containing a liquid be configured using a packaging material containing biomass polyester (hereinafter, simply referred to as “biomass polyester”) using ethylene glycol derived from biomass as a raw material. The packaging material of Patent Literature 1 includes a base layer mainly composed of a polyester composed of a diol unit and a dicarboxylic acid unit containing ethylene glycol derived from biomass, a paper base layer adhered to the base layer, A transparent vapor-deposited layer made of aluminum oxide is formed on the base material layer by a physical vapor deposition method.

JP 2015-36208 A

  Aluminum oxide has lower heat resistance than an inorganic compound such as silicon oxide, which is an example of another material forming the transparent evaporation layer. For this reason, the barrier film of the transparent vapor-deposited layer containing aluminum oxide may be deteriorated due to heat at the time of bonding the vapor-deposited film having the transparent vapor-deposited layer containing aluminum oxide to the paper base layer.

  An object of the present invention is to provide a packaging material for paper containers that can effectively solve such a problem.

  The present invention is, in order from the outside to the inside, at least an outer thermoplastic resin layer, a paper substrate layer, an adhesive resin layer, a vapor deposition film, an adhesive layer, and an inner thermoplastic resin layer, a packaging material for a paper container comprising the inner thermoplastic resin layer. The vapor-deposited film is a stretched plastic film, a transparent vapor-deposited layer provided on the inner surface of the stretched plastic film and containing aluminum oxide, and a gas barrier coating film provided on the transparent vapor-deposited layer. And the stretched plastic film of the vapor-deposited film is a packaging material for a paper container, containing a biomass-derived polyester.

  In the packaging material for a paper container according to the present invention, the gas barrier coating film of the vapor deposition film may be in contact with the adhesive layer.

  In the packaging material for a paper container according to the present invention, the adhesive resin layer is one or two selected from the group consisting of an epoxy group-containing compound, a silane group-containing compound, a carboxylic acid group-containing compound, and an acid anhydride-containing compound. A resin composition containing the above compounds may be used.

  In the packaging material for a paper container according to the present invention, the adhesive resin layer may be in contact with an outer surface of the stretched plastic film.

  In the packaging material for a paper container according to the present invention, the thickness of the adhesive resin layer may be 15 μm or more and 40 μm or less.

In the packaging material for a paper container according to the present invention, the transparent vapor-deposited layer includes a transition region, and the transition region is a time-of-flight secondary ion mass spectrometer (TOF-SIMS) that is formed by coating the vapor-deposited film from the gas barrier coating film side. ) Is detected by performing etching using the method described above, and the region between the peak position of the element-bonded Al ₂ O ₄ H that transforms to aluminum hydroxide and the interface between the transparent vapor-deposited layer and the stretched plastic film. The ratio of the thickness of the transition region to the thickness of the transparent vapor deposition layer may be 5% or more and 60% or less.

  In the packaging material for a paper container according to the present invention, the outer thermoplastic resin layer or the inner thermoplastic resin layer may include polyethylene derived from biomass.

  The present invention is a liquid paper container composed of the above-described packaging material for a paper container.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the characteristic of the transparent vapor deposition layer containing aluminum oxide deteriorates with heat.

It is sectional drawing which shows an example of the packaging material by this Embodiment. It is sectional drawing which shows an example of the vapor deposition film of the packaging material by this Embodiment. It is a figure which shows an example of the result of having analyzed the transparent vapor deposition layer with the time-of-flight secondary ion mass spectrometer. It is a figure which shows an example of the film-forming apparatus which forms a transparent vapor deposition layer on a stretched plastic film. It is sectional drawing which shows an example of the laminated body obtained by laminating a vapor deposition film and an inner thermoplastic resin layer. It is a figure which shows an example of the lamination apparatus which laminates the laminated body which has a vapor deposition film and an inner side thermoplastic resin layer, and a paper base material layer. It is a perspective view showing an example of a liquid paper container. It is a figure showing the evaluation result of Examples A1-A3. It is a figure showing the evaluation result of reference examples A1-A5. It is a figure which shows the layer structure of the packaging material for paper containers of Examples B1-B4 and Comparative Examples B1-B4. It is a figure which shows the measurement result of peeling strength, water vapor permeability, and oxygen permeability. It is a figure showing an evaluation result of filling machine seal nature.

  In the present invention, `` biomass polyester '' and `` stretched plastic film containing biomass polyester '' are those in which raw materials derived from biomass are used as raw materials at least in part, and all raw materials are derived from biomass. It does not mean.

<Packaging materials>
The packaging material 10 for a paper container according to the present embodiment will be described with reference to the drawings. FIG. 1 shows an example of a schematic sectional view of a packaging material 10 for a paper container according to the present embodiment.

  The packaging material 10 for a paper container illustrated in FIG. 1 includes, in order from the outside to the inside, at least an outer thermoplastic resin layer 11, a paper base layer 12, an adhesive resin layer 13, a vapor deposition film 14, an adhesive layer 15, and An inner thermoplastic resin layer 16. In the liquid paper container provided with the paper container packaging material 10 shown in FIG. 1, the inner thermoplastic resin layer 16 forms an inner surface (hereinafter also referred to as an inner surface) 10x of the liquid paper container. Further, the outer thermoplastic resin layer 11 forms an outer surface (hereinafter, also referred to as an outer surface) 10y of the liquid paper container. The “inside” is a side located closer to the inside of the liquid paper container when the paper container packaging material 10 forms a liquid paper container, and the “outer side” is located closer to the outside of the liquid paper container. Side.

  The paper container packaging material 10 may further include a printed layer and the like in addition to the above-described layers. For example, a print layer may be provided on the outer thermoplastic resin layer 11.

  Hereinafter, the film and the layer constituting the packaging material 10 for a paper container will be described.

[Thermoplastic resin layer]
The outer thermoplastic resin layer 11 and the inner thermoplastic resin layer 16 can be formed using a thermoplastic resin that can be melted by heat and fused to each other. Examples of the thermoplastic resin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, ethylene-α-olefin copolymer polymerized using a metallocene catalyst, polypropylene, and 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, Acid-modified polyolefin resin obtained by modifying a polyolefin resin such as methylpentene polymer, polybutene polymer, polyethylene or polypropylene with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, polyacetic acid Vinyl resin, Can be mentioned Li (meth) acrylic resin, resins such as polyvinyl chloride resin. Preferably, a low-density polyethylene, a linear (linear) low-density polyethylene, or an ethylene-α-olefin copolymer polymerized using a metallocene catalyst is used.

  The thermoplastic resin of the outer thermoplastic resin layer 11 and the inner thermoplastic resin layer 16 may include a biomass-derived material or a fossil fuel-derived material. When the thermoplastic resin layer contains a biomass-derived material, the thermoplastic resin layer may contain a biomass polyolefin which is a polymer of a monomer containing biomass-derived ethylene. Since ethylene derived from biomass is used as the monomer as a raw material, the polymerized polyolefin is derived from biomass. The content of biomass-derived ethylene in the raw material monomer does not need to be 100% by mass, and is, for example, preferably 50% or more, more preferably 80% or more. The raw material monomer may contain fossil fuel-derived ethylene, and may contain monomers of α-olefin such as butylene, hexene, and octene. Even in such a case, the obtained polymer is called biomass polyethylene. By containing an α-olefin, the polymerized polyolefin has an alkyl group as a branched structure, and therefore can be more flexible than a simple linear one.

  Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use fermented ethanol derived from biomass obtained from plant raw materials. The plant material is not particularly limited, and conventionally known plants can be used. For example, corn, sugar cane, beet, and manioc can be mentioned.

  The biomass-derived fermented ethanol refers to ethanol purified by contacting a culture solution containing a carbon source obtained from a plant material with a microorganism-derived microorganism or a product derived from a crushed product thereof, producing the ethanol, and then purifying the ethanol. For purification of ethanol from the culture solution, conventionally known methods such as distillation, membrane separation, and extraction can be applied. For example, a method of adding benzene, cyclohexane or the like and causing azeotropic distillation, or removing water by membrane separation or the like can be mentioned.

  Linear low-density polyethylene is obtained by polymerizing ethylene and a small amount of α-olefin by a low-pressure polymerization method (a gas phase polymerization method using a Ziegler-Natta catalyst or a liquid phase polymerization method using a metallocene catalyst). . Low density polyethylene is obtained by polymerizing ethylene by a high pressure polymerization method. Linear low-density polyethylene has many short molecular chains in the molecular chain and is excellent in sealing performance.

The linear low-density polyethylene and the low-density polyethylene have a density of 0.89 g / cm ³ or more and 0.93 g / cm ³ or less, more preferably 0.90 g / cm ³ or more and 0.925 g / cm ³ or less. is there. Note that the MFR of the linear low-density polyethylene may be lower than the MFR of the low-density polyethylene. The densities of the linear low-density polyethylene and the low-density polyethylene are values measured according to the method specified in the method A of JIS K7112-1980 after annealing described in JIS K6760-1995. When the density of the linear low-density polyethylene and the low-density polyethylene is less than 0.89 g / cm ³ , the slipperiness of the thermoplastic resin layers 11 and 16 is reduced. When the density of the linear low-density polyethylene and the low-density polyethylene exceeds 0.93 g / cm ³ , the sealing properties of the thermoplastic resin layers 11 and 16 deteriorate.

  The linear low-density polyethylene and the low-density polyethylene are 0.1 g / 10 min or more and 10 g / 10 min or less, preferably 0.2 g / 10 min or more and 9 g / 10 min or less, more preferably 1 g / 10 min or more and 8. It has a melt flow rate (MFR) of 5 g / 10 minutes or less. Note that the MFR of the linear low-density polyethylene may be lower than the MFR of the low-density polyethylene. The melt flow rate is a value measured by the method A at a temperature of 190 ° C. and a load of 21.18 N in a method specified in JIS K7210-1995. When the MFR of the linear low-density polyethylene and the low-density polyethylene is less than 0.1 g / 10 minutes, an extrusion load is applied during molding. Further, when the MFR of the linear low-density polyethylene and the low-density polyethylene exceeds 10 g / 10 minutes, the resin flows too much, which causes a problem of hermeticity, which is not preferable.

Examples of biomass polyethylene include Brasschem's biomass-derived linear low-density polyethylene (trade name: SLL118, density: 0.916 g / cm ³ , MFR: 1.0 g / 10 min, biomass degree 87%), Braschem Low-density polyethylene (trade name: SBC818, density: 0.918 g / cm ³ , MFR: 8.1 g / 10 min, biomass degree 95%) manufactured by Biomass.

  As the linear low-density polyethylene derived from biomass, for example, one using sugarcane as a raw material is produced. The degree of dispersion of such a sugarcane-derived linear low-density polyethylene can be 4 or more and 7 or less. On the other hand, the degree of dispersion of fossil-derived linear low-density polyethylene is usually 1.5 or more and 3.5 or less.

  The outer thermoplastic resin layer 11 is preferably made of one or more of the above-described low-density polyethylene derived from fossil fuel or biomass, linear low-density polyethylene, and linear low-density polyethylene using a metallocene catalyst. Including a single layer or multiple layers. The outer thermoplastic resin layer 11 is formed by using one or more of the above-described resins, melt-extruding the same using an extruder or the like, and melt-extruding and laminating on the paper base material layer 12. Can be done. For example, the outer thermoplastic resin layer 11 is a single-layer thermoplastic resin layer containing low-density polyethylene. The thickness of the outer thermoplastic resin layer 11 is, for example, not less than 15 μm and not more than 35 μm.

  The inner thermoplastic resin layer 16 is preferably made of one or more of the above-described low-density polyethylene derived from fossil fuel or biomass, linear low-density polyethylene, and linear low-density polyethylene using a metallocene catalyst. Including a single layer or multiple layers. The inner thermoplastic resin layer 16 uses one or more of the above-described resins, and previously manufactures a resin film or sheet from this resin, and then connects the resin film or sheet with the adhesive layer 15 interposed therebetween. Then, it can be formed by dry lamination and lamination on the vapor deposition film 14. The thickness of the inner thermoplastic resin layer 16 is, for example, 30 μm or more and 80 μm or less, and preferably 40 μm or more and 60 μm or less.

[Paper base layer]
The paper base material layer 12 functions as a base material layer for holding the liquid paper container 100, and is preferably a material that can impart strength as a packaged product to the laminate. The paper used as the paper base layer has a basis weight of 100 g / m ² or more and 700 g / m ² or less, preferably 150 g / m ² or more and 600 g / m ² or less, more preferably 200 g / m ² or more and 500 g / m ² or less. Have The paper base layer is intended for all white paperboards, but it is particularly preferable to use ivory paper, milk carton base paper, cup base paper using natural pulp from the viewpoint of safety.

  Further, the paperboard used in the present invention may use neutral rosin, alkyl ketene dimer, alkenyl succinic anhydride as a sizing agent, and use cationic polyacrylamide or cationic starch as a fixing agent. Is also good. It is also possible to use a sulfuric acid band to make paper in a neutral region of pH 6 or more and pH 9 or less. In addition, if necessary, in addition to the above-mentioned sizing agent, other than the fixing agent, various fillers for papermaking, a retention enhancer, a dry paper strength enhancer, a wet paper strength enhancer, a binder, a dispersant, a flocculant, a plasticizer. Agents and adhesives may be appropriately contained.

[Printing layer]
The printed layer is used to display characters, numbers, pictures, graphics, symbols, patterns, etc., for decoration, display of contents, display of shelf life, display of manufacturers, sellers, etc. This is a layer for forming a desired arbitrary print pattern. The printing layer can be provided as needed, for example, can be provided on the outer thermoplastic resin layer 11. The printing layer may be provided on the entire surface of the outer thermoplastic resin layer 11, or may be provided on a part thereof. The printing layer can be formed using a conventionally known pigment or dye, and the forming method is not particularly limited.

[Evaporated film]
FIG. 2 is a cross-sectional view illustrating an example of the vapor deposition film 14. The vapor deposition film 14 has a stretched plastic film 141, a transparent vapor deposition layer 142 provided on the inner surface of the stretched plastic film 141, and a gas barrier coating film 143 provided on the transparent vapor deposition layer 142. . The stretched plastic film 141 is in contact with the adhesive resin layer 13, and the gas barrier coating film 143 is in contact with the adhesive layer 15. Hereinafter, each layer will be described.

(Stretched plastic film)
The stretched plastic film 141 is a polyester film stretched in a predetermined direction. The stretched plastic film 141 may be a uniaxially stretched film stretched in one predetermined direction or a biaxially stretched film stretched in two predetermined directions. The stretching direction of the stretched plastic film 141 is not particularly limited. For example, the stretched plastic film 141 may be stretched in the height direction of the liquid paper container constituted by the paper container packaging material 10, or may be stretched in the width direction of the liquid paper container.

  The stretched plastic film 141 is a resin composition containing biomass-derived polyester (hereinafter, also referred to as biomass polyester). Biomass polyester is a polyester in which the diol unit is ethylene glycol derived from biomass and the dicarboxylic acid unit is dicarboxylic acid derived from fossil fuel. The content of polyethylene terephthalate in the stretched plastic film 141 may be 80% by mass or more, 90% by mass or more, or 95% by mass or more. The stretched plastic film 141 contains, for example, 5% by mass or more of biomass polyester based on the entire resin composition of the stretched plastic film 141.

  Since biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol, a polyester film synthesized using biomass-derived ethylene glycol is mechanically different from a conventional fossil fuel-derived polyester film. There is no inferiority in physical properties such as characteristics. Therefore, since the stretched plastic film 141 and the packaging material 10 for a paper container having the same have a layer made of a carbon neutral material, the stretched plastic film manufactured from a raw material obtained from a conventional fossil fuel and a paper container having the same are provided. As compared to packaging materials for fossils, the amount of fossil fuel used can be reduced, and the environmental burden can be reduced.

  Ethylene glycol derived from biomass is derived from ethanol (biomass ethanol) produced from biomass such as sugarcane and corn. For example, biomass-derived ethylene glycol can be obtained from biomass ethanol by a conventionally known method, for example, by producing ethylene glycol via ethylene oxide. Further, commercially available biomass ethylene glycol may be used. For example, biomass ethylene glycol commercially available from Indiaglycol Co., Ltd. can be suitably used.

  As the dicarboxylic acid unit of the polyester, a dicarboxylic acid derived from a fossil fuel is used. As the dicarboxylic acid, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and a derivative 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. Of these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the derivative of the aromatic dicarboxylic acid.

  The resin composition forming the stretched plastic film 141 may be a fossil fuel-derived polyester, a fossil fuel-derived polyester product recycled polyester, a biomass-derived polyester product recycled polyester, or the like at a ratio of 5% by mass to 45% by mass. Species or two or more species may be contained.

Since carbon dioxide in the atmosphere contains ¹⁴ C at a constant rate (105.5 pMC), plants that take in carbon dioxide in the atmosphere and grow, for example, corn, also have a ¹⁴ C content of about 105.5 pMC. It is known that It is also known that fossil fuels hardly contain ¹⁴ C. Therefore, the ratio of carbon derived from biomass can be calculated by measuring the ratio of ¹⁴ C contained in all the carbon atoms in the polyester.

The biomass degree can be used as an index indicating the ratio of the biomass-derived raw material. In the present embodiment, the “degree of biomass” indicates the weight ratio of the biomass-derived component. Taking polyethylene terephthalate as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1: 1. Is used, since the weight ratio of the biomass-derived component in polyethylene terephthalate is 31.25%, the biomass degree is 31.25% (molecular weight of ethylene glycol derived from biomass / molecular weight of 1 unit of polyester polymerization). = 60/192).
Since the weight ratio of the biomass-derived component is 0% in the fossil fuel-derived polyester, the biomass degree of the fossil fuel-derived polyester is 0%. In the present embodiment, the degree of biomass in the stretched plastic film 141 is preferably 5.0% or more, and more preferably 10.0% or more, in order to exhibit the effect as a carbon offset material. . Further, the degree of biomass in the stretched plastic film 141 may be 30.0% or less in view of problems in the production process of the film and physical properties.

  The stretched plastic film 141 can be formed by using the resin composition described above and forming a film by a T-die method, for example. Specifically, after drying the above-described resin composition, the resin composition is supplied to a melt extruder heated to a temperature of from the melting point of the resin composition (Tm) to Tm + 70 ° C. to melt the resin composition. For example, a film can be formed by extruding a sheet from a die such as a T-die, and rapidly cooling and solidifying the extruded sheet with a rotating cooling drum or the like. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder or the like can be used according to the purpose.

  The film obtained as described above is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the machine direction to form a machine-stretched film. This stretching is preferably performed by utilizing the peripheral speed difference between two or more rolls. The longitudinal stretching is usually performed in a temperature range of 50 ° C. or more and 100 ° C. or less. Further, the magnification of the longitudinal stretching is preferably 2.5 times or more and 4.2 times or less, although it depends on the required characteristics of the film application. If the stretching ratio is less than 2.5 times, the thickness unevenness of the film becomes large and it is difficult to obtain a good film.

  The longitudinally stretched film is successively subjected to transverse stretching, heat fixation, and heat relaxation processing steps to form a biaxially stretched film. The transverse stretching is usually performed in a temperature range of 50 ° C or more and 100 ° C or less. The transverse stretching ratio is preferably 2.5 times or more and 5.0 times or less, though it depends on the required characteristics of the application. If the ratio is less than 2.5 times, the thickness unevenness of the film becomes large and it is difficult to obtain a good film. If the ratio exceeds 5.0 times, breakage tends to occur during film formation.

  After the transverse stretching, a heat setting treatment is performed. The preferable temperature range of the heat setting is Tg of PET + 70 to Tm-10 ° C. Further, the heat fixing time is preferably from 1 second to 60 seconds. Further, for applications requiring a reduction in the heat shrinkage, a heat relaxation treatment may be performed as necessary.

The thickness of the stretched plastic film 141 obtained as described above is arbitrary depending on its use. The thickness of the stretched plastic film 141 is, for example, 5 μm or more, and may be 8 μm or more. Further, the thickness of the stretched plastic film 141 is, for example, 100 μm or less, may be 50 μm or less, may be 30 μm or less, or may be 25 μm or less. The range of the thickness of the stretched plastic film 141 can be determined by any combination of the above-described lower limit candidate value and the upper limit candidate value. Further, the breaking strength of the film in the MD direction 5 kgf / mm ² or more 40 kgf / mm ² or less, at 35 kgf / mm ² or less 5 kgf / mm ² or more in the TD direction, elongation at break, 50% MD direction Not less than 350% and not less than 50% and not more than 300% in the TD direction. The shrinkage when left in a temperature environment of 150 ° C. for 30 minutes is 0.1% or more and 5% or less.

(Transparent evaporation layer)
The transparent evaporation layer 142 is a thin film of an inorganic oxide containing aluminum oxide as a main component. The transparent vapor-deposited layer 142 may include an aluminum compound such as aluminum oxide, aluminum nitride, carbide, hydroxide alone or a mixture thereof. Further, the transparent evaporation layer 142 contains an aluminum compound as a main component, and includes silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, magnesium oxide, titanium oxide, tin oxide, indium oxide, zinc oxide, zirconium oxide, and the like. Or a metal oxide, a metal nitride, a carbide thereof, a mixture thereof, or the like.

(Gas barrier coating film)
The gas barrier coating film 143 serves to mechanically and chemically protect the transparent vapor-deposited layer 142 and improve the barrier property of the vapor-deposited film 14, and is laminated so as to be in contact with the transparent vapor-deposited layer 142. The gas barrier coating film 143 is a cured film formed by a coating agent for a gas barrier coating film made of a resin composition containing a metal alkoxide, a hydroxyl group-containing water-soluble resin, and a silane coupling agent optionally added. is there.

  The mass ratio of the hydroxyl group-containing water-soluble resin / metal alkoxide in the resin composition is preferably 5/95 or more and 20/80 or less, more preferably 8/92 or more and 15/85 or less. When it is smaller than the above range, the barrier effect of the barrier coating layer tends to be insufficient, and when it is larger than the above range, the rigidity and brittleness of the barrier coating layer tend to increase.

  The thickness of the gas barrier coating film 143 is preferably 100 nm or more and 800 nm or less. When the thickness is smaller than the above range, the barrier effect of the gas barrier coating film 143 tends to be insufficient, and when the thickness is larger than the above range, rigidity and brittleness tend to increase.

The metal alkoxide has the general formula R ₁ nM (OR ₂ ) m (where R ₁ and R ₂ represent a hydrogen atom or an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n Represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents a valence of M. Even if each of a plurality of R ₁ and R _{2 in} one molecule is the same, (It may be different.) ... represented by (I).

  Specific examples of the metal atom represented by M in the metal alkoxide include silicon, zirconium, titanium, aluminum, tin, lead, borane, and the like. For example, an alkoxy group in which M is Si (silicon) Preference is given to using silanes.

In general formula (I), specific examples of OR _2, a hydroxyl group, a methoxy group, an ethoxy group, n- propoxy group, n- butoxy group, i- propoxy group, a butoxy group, 3-methacryloxy groups. Examples include an alkoxy group such as a 3-acryloxy group and a phenoxy group, and a phenoxy group.

In the above, specific examples of R ₁ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a phenyl group, a p-styryl group, a 3-chloropropyl group, a trifluoromethyl group, a vinyl group, and a γ-glycol. Examples include a sidoxypropyl group, a methacryl group, and a γ-aminopropyl group.

  Specific examples of alkoxysilanes include, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, Methyltributoxysilane, methyltriphenoxysilane, phenylphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxy Silane, isopropyltriethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, vinyl Methoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri Methoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-chloropropyltriethoxysilane, trifluoromethyltrimethoxysilane, 1,6-bis Various alkoxysilanes such as (trimethoxysilyl) hexane, and phenoxysilanes are exemplified. In the present embodiment, polycondensates of these alkoxysilanes can also be used, and specifically, for example, polytetramethoxysilane, polytetraethoxysilane, and the like can be used.

  The silane coupling agent is used to adjust the cross-link density of the cured film made of the metal alkoxide and the hydroxyl group-containing water-soluble resin to obtain a film having barrier properties and heat-resistant water treatment properties.

The silane coupling agent has a general formula: R ₃ nSi (OR ₄ ) 4-n (II)
(Wherein, R ₃ and R ₄ each independently represent an organic functional group, and n is 1 to 3.)
It is represented by

In the general formula (II), R ₃ is, for example, a hydrocarbon group such as an alkyl group or an alkylene group, an epoxy group, a (meth) acryloxy group, a ureido group, a vinyl group, an amino group, an isocyanurate group or an isocyanate group. And a functional group having the formula: Specifically, at least one of two or three R ₃ is preferably a functional group having an epoxy group, and is preferably a 3-glycidoxypropyl group or a 2- (3,4 epoxycyclohexyl) group. Is more preferable. Note that R ₃ may be the same or different.

In the general formula (II), R ₄ is, for example, an organic functional group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms which may have a branch, or 3 to 4 carbon atoms. 7 is an alkoxyalkyl group. For example, examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a sec-butyl group. Examples of the alkoxyalkyl group having 3 to 7 carbon atoms include methyl ethyl ether, diethyl ether, methyl propyl ether, methyl isopropyl ether, ethyl propyl ether, ethyl isopropyl ether, methyl butyl ether, ethyl butyl ether, methyl sec-butyl ether, and ethyl sec. And a group in which one hydrogen atom has been removed from a linear or branched ether such as -butyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, and the like. (OR ₄ ) may be the same or different.

  Examples of the silane coupling agent represented by the general formula (II) include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane when n = 1. When n = 2, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and the like can be mentioned, and when n = 3, 3-glycidoxypropyldimethylmethoxysilane, 3-glycidyl Sidoxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) dimethylmethoxysilane, 2- (3,4-epoxycyclohexyl) dimethylethoxysilane and the like can be mentioned.

  In particular, the crosslink density of the cured film of the barrier coating layer using 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane is lower than the crosslink density in the system using trialkoxysilane. Become. Therefore, while being excellent as a film having gas barrier properties and heat-resistant water treatment properties, it becomes a flexible cured film and also has excellent flex resistance, so that a packaging material using the barrier film has gas barrier properties even after the Gelboflex test. Hard to deteriorate.

  The silane coupling agent may be used in a mixture of n = 1, 2, 3, and the amount ratio and the amount of the silane coupling agent used are determined by the design of the cured film of the barrier coating layer. .

  The hydroxyl group-containing water-soluble resin can be dehydrated and co-condensed with a metal alkoxide, and has a saponification degree of preferably 90% or more and 100% or less, more preferably 95% or more and 100% or less, and more preferably 99% or more and 100% or less. % Is more preferable. If the saponification degree is smaller than the above range. The hardness of the barrier coating layer tends to decrease.

  Specific examples of the hydroxyl group-containing water-soluble resin include, for example, a polyvinyl alcohol resin, an ethylene-vinyl alcohol copolymer, a polymer of a bifunctional phenol compound and a bifunctional epoxy compound, and the like. They may be used, or two or more kinds may be used as a mixture, or may be used after copolymerization. Among these, polyvinyl alcohol is particularly preferable because of its excellent flexibility and affinity, and polyvinyl alcohol-based resin is preferable.

Specifically, for example, a polyvinyl alcohol-based resin obtained by saponifying polyvinyl acetate or an ethylene / vinyl alcohol copolymer obtained by saponifying a copolymer of ethylene and vinyl acetate is used. can do.
Examples of such a polyvinyl alcohol-based resin include PVA-124 manufactured by Kuraray Co., Ltd. (degree of saponification = 99%, degree of polymerization = 2,400) and Nippon Synthetic Chemical Industry Co., Ltd. “Gohsenol NM-14 (degree of saponification) = 99%, degree of polymerization = 1,400).

(Preferred configuration of vapor-deposited film)
Next, a preferred configuration of the vapor deposition film 14 in the thickness direction will be described with reference to FIG. FIG. 3 shows a time-of-flight secondary ion mass spectrometry (TOF-SIMS) while repeatedly soft-etching the surface of the vapor-deposited film 14 on the gas barrier coating film 143 side by a Cs (cesium) ion gun at a constant rate. FIG. 4 is a diagram showing the results of measuring ions derived from the transparent vapor-deposited layer 142 and ions derived from the stretched plastic film 141 by using FIG. The transparent vapor-deposited layer 142 of the vapor-deposited film 14 includes a transition region specified by the graph analysis diagram shown in FIG.

The transition region is a position T _{2 of} a peak T _{2 of} the element-bonded Al ₂ O ₄ H that is converted into aluminum hydroxide and is detected by etching the vapor-deposited film 14 from the gas barrier coating film 143 side using TOF-SIMS. When a region between the interface T ₁ of the transparent deposition layer 142 and the stretched plastic film 141. Interface T ₁ of the transparent deposition layer 142 and the stretched plastic film 141, the intensity of the graph element C ₆ is identified as a position that is half the strength of the element C ₆ in stretched plastic film 141. 3, reference numeral W ₁ represents the thickness of the transition region.

Transparent ratio of thickness W ₁ of the transition region to the thickness of the deposited layer 142 (hereinafter, referred to as modified rate of the transition region) is desirably 60% or less than 5%. If the transformation rate exceeds 60%, the adhesion of the transparent vapor-deposited layer 142 to the stretched plastic film 141 may be reduced when heat is applied to the vapor-deposited film 14. Moreover, the barrier property of the vapor deposition film 14 against water vapor may be reduced. The metamorphic rate may be 30% or less, 25% or less, or 20% or less. Moreover, the metamorphosis rate may be 10% or more, and may be 15% or more. The range of the metamorphic rate can be determined by any combination of the above-mentioned lower limit candidate value and upper limit candidate value.

  The interface between the stretched plastic film 141 and the transparent vapor-deposited layer 142 receives mechanical and chemical stress due to heat. Therefore, in order to suppress a decrease in adhesion and barrier properties, it is important to firmly cover the stretched plastic film 141 with the transparent evaporated layer 142 at the interface between the stretched plastic film 141 and the transparent evaporated layer 142.

  Aluminum hydroxide has good adhesion to a plastic substrate due to its chemical structure, and has a high water vapor barrier property because it forms a network itself and is dense. However, the bond structure based on the hydrogen bond between the aluminum hydroxide and the base material is liable to be broken microscopically due to thermal stress. Further, the aluminum hydroxide network easily penetrates into the film due to the affinity of the water molecule and the aluminum hydroxide at the grain interface.

In this embodiment mode, in order to minimize the transition region at the interface between the aluminum hydroxide and the plastic substrate in the aluminum oxide vapor-deposited film, attention is paid to element-bonded Al ₂ O ₄ H, and the amount of Al ₂ O ₄ H is controlled. Thus, aluminum hydroxide generated from element-bonded Al ₂ O ₄ H due to thermal stress is suppressed, and the ratio of aluminum oxide film with relatively little aluminum hydroxide is increased, so that microscopic deposition by water molecules due to thermal stress is achieved. It is intended to suppress film destruction and interface destruction with a plastic substrate. Thereby, it is possible to provide the deposited film 14 having unprecedented adhesion and barrier properties.

  The aluminum oxide vapor-deposited film can be formed by depositing a vapor-deposited film on the surface of a plastic substrate pretreated with oxygen plasma. As a vapor deposition method for forming a vapor deposition film, various vapor deposition methods among physical vapor deposition and chemical vapor deposition can be applied. The physical vapor deposition method can be selected from the group consisting of a vapor deposition method, a sputtering method, an ion plating method, an ion beam assist method, and a cluster ion beam method, and the chemical vapor deposition method includes a plasma CVD method, a plasma polymerization method, and a thermal polymerization method. It can be selected from the group consisting of a CVD method and a catalytic reaction type CVD method. In this embodiment mode, a physical vapor deposition method is preferable.

  A specific example of a method for obtaining the graph of FIG. 3 will be described. First, etching is performed from the outermost surface of the gas barrier coating film 143 using Cs, and element bonding at the interface between the gas barrier coating film 143, the transparent vapor-deposited layer 142, and a film such as the stretched plastic film 141, and element bonding of the vapor-deposited film. Perform an analysis. Thereby, the graph shown in FIG. 3 can be obtained.

  Next, a specific example of the method for analyzing the graph of FIG. 3 will be described. Here, the case where the gas barrier coating film 143 contains silicon oxide will be described.

First, in the graph, the position where the intensity of SiO ₂ (mass number 59.96), which is a constituent element of the gas barrier coating film 143, is half of the intensity of the gas barrier coating film 143 is defined by the gas barrier coating film 143 and the transparent vapor deposition. It is specified as an interface of the layer 142. Next, a position where the strength of C ₆ (mass number 72.00), which is a constituent material of the stretched plastic film 141, becomes half of the strength in the stretched plastic film 141 is defined as an interface between the stretched plastic film 141 and the transparent evaporation layer 142. Identify. Further, the distance in the thickness direction between the two interfaces is adopted as the thickness of the transparent vapor deposition layer 142.

Next, a peak representing the measured element-bonded Al ₂ O ₄ H (mass number 118.93) is determined, and a region from the peak to the interface is defined as a transition region. However, when the component of the gas barrier coating film 143 is made of a material having the same mass number as Al ₂ O ₄ H (mass number 118.93), it is necessary to separate the waveform of 118.93.

When reactants AlSiO ₄ and hydroxide Al ₂ O ₄ H are generated at the interface between the gas barrier coating film 143 and the transparent vapor deposition layer 142, the reactant AlSiO ₄ and the hydroxide Al ₂ O ₄ H are formed at the interface between the stretched plastic film 141 and the transparent vapor deposition layer 142. Any Al ₂ O ₄ H present can be separated. As described above, the separation of the waveform can be appropriately dealt with according to the material of the gas barrier coating film 143.

  In the waveform separation, for example, a profile having a mass number of 118.93 obtained by TOF-SIMS is subjected to non-linear curve fitting using a Gaussian function, and separation of overlapping peaks is performed using the least squares method Levenberg Marquardt algorithm. It can be carried out.

[Adhesive resin layer]
The adhesive resin layer 13 is a layer that contains an adhesive resin and adheres the base material including the paper base material layer 12 and the film including the vapor deposition film 14. The adhesive resin layer 13 is formed by, for example, a sand lamination method.

  The adhesive resin of the adhesive resin layer 13 is preferably an epoxy group-containing compound, a silane group-containing compound, a carboxylic acid group-containing compound, and one or more compounds selected from the group consisting of acid anhydride-containing compounds. It is a resin composition containing. For example, a polyethylene resin or a polypropylene resin can be used. Thereby, the thermal stress applied to the vapor-deposited film 14 in the step of bonding the paper base layer 12 and the stretched plastic film 141 of the vapor-deposited film 14 by the sand lamination method via the adhesive resin layer 13 can be reduced. Thereby, it can suppress that the gas barrier property of the vapor deposition film 14 falls. Further, since the adhesion between the adhesive resin layer 13 and the stretched plastic film 141 of the vapor deposition film 14 is high, an anchor coat layer between the adhesive resin layer 13 and the stretched plastic film 141 can be eliminated. That is, the adhesive resin layer 13 can be provided so that the outer surface of the stretched plastic film 141 directly contacts the adhesive resin layer 13.

When a polyethylene resin is used as the adhesive resin constituting the adhesive resin layer 13, the density is preferably in the range of 920 to 970 kg / m ³ , and more preferably in the range of 920 to 965 kg / m ³ because of excellent heat resistance. preferable. By setting the density of the adhesive resin constituting the adhesive resin layer 13 within the above range, when heat is applied to the paper container packaging material 10, the generation of pinholes, the peeling of the transparent vapor-deposited layer 142 and the wrinkles are prevented. Can be suppressed. In addition, it is possible to suppress the generation of thermal pinholes caused by heat when manufacturing the liquid paper container. The melting point of the adhesive resin forming the adhesive resin layer 13 is desirably higher than the melting point of the inner thermoplastic resin layer 16. For example, the melting point is preferably 90 ° C. or higher, more preferably 100 ° C. or higher.

  As the adhesive resin constituting the adhesive resin layer 13, a polyethylene resin is preferable in consideration of adhesiveness with the paper base layer 12 and the vapor deposition film 14. Examples of such a polyethylene resin include ethylene homopolymers, ethylene / α-olefin copolymers, and compositions thereof, and the molecular chain may be linear, and may have a long carbon number of 6 or more. It may have a chain branch.

  Examples of the ethylene homopolymer include a medium / low pressure method ethylene homopolymer, a high pressure method low density polyethylene, and the like. The medium / low pressure ethylene homopolymer can be obtained by a conventionally known medium / low pressure ionic polymerization method. The high-pressure low-density polyethylene can be obtained by a conventionally known high-pressure radical polymerization method.

  Examples of the α-olefin used in the ethylene / α-olefin copolymer include propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-pentene, 1-hexene, and 1-heptene. , 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, etc., and one or more of these are used. The method for obtaining the ethylene / α-olefin copolymer is not particularly limited, and examples thereof include a Ziegler-Natta catalyst, a Phillips catalyst, and a high / medium / low pressure ionic polymerization method using a single-site catalyst. it can. Such a copolymer can be conveniently selected from commercially available products.

  Examples of the epoxy group-containing compound contained in the adhesive resin constituting the adhesive resin layer 13 include epoxidized vegetable oil (epoxidation of unsaturated double bond of natural vegetable oil), glycidyl ether type, glycidylamine type, glycidyl ester type and the like. Is mentioned. Among them, epoxidized vegetable oil is more preferable from the viewpoint of safety when used in food packaging materials. For example, epoxidized soybean oil, epoxidized linseed oil, epoxidized olive oil, epoxidized safflower oil, epoxidized corn oil and the like are used. The content of such an epoxy group-containing compound is, for example, 0.01 to 10 parts by weight, preferably 0.01 to 5.0 parts by weight, based on 100 parts by weight of the adhesive resin constituting the adhesive resin layer 13. . If the amount is less than 0.01 part by weight, the adhesive strength to the vapor deposition film 14 is insufficient. If the amount exceeds 10 parts by weight, blocking and especially when used for food packaging are accompanied by an odor, which is not preferable.

  As the silane group-containing compound contained in the adhesive resin constituting the adhesive resin layer 13, a silane oligomer is suitably used. More specifically, a silane oligomer containing any one of an epoxy group, a mercapto group, and an alkoxy group, or some of these in a molecule is desirable in order to increase the adhesiveness. The silane oligomer is added in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the adhesive resin constituting the adhesive resin layer 13. If the blending amount of the silane oligomer is less than 0.01 part by weight, the adhesive strength to the vapor-deposited film 14 becomes insufficient.

  As the carboxylic acid group-containing compound contained in the adhesive resin constituting the adhesive resin layer 13, an ethylene-unsaturated carboxylic acid or a copolymer thereof with an esterified product thereof can be used. More specifically, an ethylene-acrylic acid copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methacrylic acid copolymer, and an ethylene-methyl methacrylate copolymer are exemplified. In addition, an ionomer resin in which ethylene-unsaturated carboxylic acid molecules are cross-linked with metal ions can also be used.

  The acid anhydride-containing compound contained in the adhesive resin constituting the adhesive resin layer 13 is preferably a maleic acid-modified polyolefin resin such as a maleic acid-modified polyethylene resin or a maleic acid-modified polypropylene resin, and is preferably a maleic anhydride-modified resin. Maleic anhydride-modified polyolefin resins such as polyethylene resins and maleic anhydride-modified polypropylene resins are more preferred. The maleic acid-modified polyolefin-based resin is obtained by graft-polymerizing maleic acid to a polyolefin-based resin.

  Also, the thickness of the adhesive resin layer of the adhesive resin layer 13 is not particularly limited, but is preferably 15 μm or more and 40 μm or less. By setting the thickness of the adhesive resin layer 13 within the above range, it is possible to effectively suppress the occurrence of thermal pinholes when molding the liquid paper container. If the thickness is less than 15 μm, the adhesiveness between the paper base layer 12 and the deposition film 14 may be insufficient. Further, when the thickness exceeds 40 μm, the property of the transparent vapor-deposited layer 142 of the vapor-deposited film 14 is reduced due to thermal stress during the step of laminating the paper base layer 12 and the vapor-deposited film 14 using the adhesive resin in a molten state. There is a risk of deterioration.

  The resin constituting the adhesive resin layer 13 includes, in addition to the various compounds described above, if necessary, antioxidants, light stabilizers, antistatic agents, lubricants, antiblocking agents, and the like, which are generally used in polyolefin resins. May be added in a range that does not impair the purpose of the present invention.

[Adhesive layer]
The adhesive layer 15 is a layer for bonding a film including the vapor deposition film 14 and a film including the inner thermoplastic resin layer 16 by a dry lamination method. The adhesive layer 15 is formed by applying and drying an adhesive on the surface of the film on the side to be laminated, of the film including the vapor deposition film 14 and the film including the inner thermoplastic resin layer 16. Examples of the adhesive forming the adhesive layer 15 include a one-pack or two-pack hardened or non-hardened type vinyl, (meth) acrylic, polyamide, polyester, polyether, polyurethane, Adhesives such as a solvent type such as an epoxy type, a rubber type, and the like, an aqueous type, and an emulsion type can be used. As the two-part curable adhesive, a cured product of a polyol and an isocyanate compound can be used. As the method for coating the adhesive, for example, a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fonten method, a transfer roll coating method, or another method can be used.

  The adhesive layer 15 may include a biomass-derived component. For example, when the adhesive layer 15 contains a cured product of a polyol and an isocyanate compound, at least one of the polyol and the isocyanate compound may contain a biomass-derived component.

  By adhering the film including the vapor-deposited film 14 and the film including the inner thermoplastic resin layer 16 by a dry laminating method, heat-induced damage occurs in the vapor-deposited film 14 as compared with the case of using a sand laminating method. Can be suppressed. For example, it is possible to prevent the transparent vapor-deposited layer 142 from peeling off from the stretched plastic film 141 or to reduce the gas barrier property of the vapor-deposited film 14.

<Production method of packaging material>
Next, an example of a method for manufacturing the packaging material 10 for a paper container will be described. First, an example of a method for manufacturing the vapor deposition film 14 will be described.

(Manufacturing process of vapor deposition film)
First, a stretched plastic film 141 is prepared. Subsequently, a transparent vapor-deposited layer 142 containing aluminum oxide is formed on the inner surface of the stretched plastic film 141. FIG. 4 is a diagram illustrating an example of the film forming apparatus 60. Hereinafter, the film forming apparatus 60 and a film forming method using the film forming apparatus 60 will be described.

  As shown in FIG. 4, in the film forming apparatus 60, partitions 85 a to 85 c are formed in the decompression chamber 62. The partition walls 85a to 85c form a substrate transfer chamber 62A, a plasma pretreatment chamber 62B, and a film formation chamber 62C. In particular, the plasma pretreatment chamber 62B and the film formation chamber are defined as spaces surrounded by the partition walls and the partition walls 85a to 85c. 62C is formed, and each chamber is further provided with an exhaust chamber as needed.

  The plasma pretreatment chamber 62B and the plasma pretreatment process in the plasma pretreatment chamber 62B will be described. In the plasma pretreatment chamber 62B, a part of the plasma pretreatment roller 70 that transports the stretched plastic film 141 to be subjected to the pretreatment and enables the plasma treatment is provided so as to be exposed to the base material transport chamber 62A. ing. The stretched plastic film 141 moves to the plasma pretreatment chamber 62B while being wound.

  The plasma pretreatment chamber 62B and the film formation chamber 62C are provided in contact with the base material transfer chamber 62A, and can be moved without allowing the stretched plastic film 141 to come into contact with the atmosphere. Further, the pretreatment chamber 62B and the base material transfer chamber 62A are connected by a rectangular hole, and a part of the plasma pretreatment roller 70 protrudes toward the base material transfer chamber 62A through the rectangular hole. A gap is opened between the wall of the transfer chamber and the pretreatment roller 70, and the stretched plastic film 141 can be moved from the base material transfer chamber 62A to the film formation chamber 62C through the gap. The structure between the base material transfer chamber 62A and the film formation chamber 62C has the same structure, and the stretched plastic film 141 can be moved without being exposed to the atmosphere.

  The substrate transfer chamber 62A serves as a winding means for winding the stretched plastic film 141 having the vapor-deposited film formed on one side, which has been moved to the substrate transfer chamber 62A again by the film forming roller 75, in a roll shape. A take-up roller is provided so that the stretched plastic film 141 having the deposited film formed thereon can be taken up.

  When manufacturing the vapor deposition film 14 having the aluminum oxide vapor deposition film, the plasma pretreatment chamber 62B is configured to divide the space where the plasma is generated from other regions and efficiently evacuate the opposing space. In addition, the control of the plasma gas concentration is facilitated, and the productivity is improved. The pretreatment pressure formed by reducing the pressure can be set and maintained at about 0.1 Pa or more and 100 Pa or less, and in particular, the treatment pressure of the oxygen plasma pretreatment in order to obtain a preferable transformation rate of the transition region of the aluminum oxide deposition film. Is preferably 1 Pa or more and 20 Pa or less, and may be 10 Pa or less, or 5 Pa or less. The range of the pretreatment pressure can be determined by any combination of the above-described lower limit candidate value and upper limit candidate value.

  The transport speed of the stretched plastic film 141 is not particularly limited, but can be at least 200 to 1000 m / min from the viewpoint of production efficiency. The conveying speed of the processing is preferably 300 to 800 m / min.

  The plasma pre-treatment roller 70 constituting the plasma pre-treatment device prevents the stretched plastic film 141 from contracting or being damaged by heat during the plasma treatment by the plasma pre-treatment means, and uniformly applies the oxygen plasma P to the stretched plastic film 141. It is intended to be widely applied. It is preferable that the pretreatment roller 70 can be adjusted to a constant temperature between −20 ° C. and 100 ° C. by adjusting the temperature of the temperature adjusting medium circulating in the pretreatment roller.

  The plasma pretreatment unit includes a plasma supply unit and a magnetic forming unit. The plasma pretreatment means cooperates with the plasma pretreatment roller 70 to confine the oxygen plasma P near the surface of the stretched plastic film 141.

  The plasma pretreatment means is provided so as to cover a part of the pretreatment roller 70. Specifically, the plasma supply means 72 and the magnetic forming means 73 constituting the plasma pretreatment means are arranged along the surface near the outer periphery of the pretreatment roller 70. The plasma supply means 72 includes a plasma supply nozzle for supplying a plasma source gas. The magnetic forming means 73 has a magnet or the like to promote generation of the plasma P. Further, the plasma pretreatment means has an electrode 71 to which a voltage is applied between the plasma pretreatment means 70 and the pretreatment roller 70. Although FIG. 4 shows an example in which the electrode 71 and the plasma supply means 72 are separate members, the present invention is not limited to this. Although not shown, the electrode 71 and the plasma supply means 72 may be formed by an integral member.

  By generating a plasma P in a space between the pretreatment roller 70 and the magnetic forming means 73 and forming a region having a high plasma density near the surface of the pretreatment roller 70 and the stretched plastic film 141, the stretched plastic The inner surface of the film 141 can be subjected to oxygen plasma pretreatment to form a plasma-treated surface.

  The plasma supply means 72 of the plasma pretreatment means includes a raw material volatile supply device 68 connected to a plasma supply nozzle provided outside the decompression chamber 62, and a raw material gas supply line for supplying a raw material gas from the device. As the supplied plasma raw material gas, oxygen alone or a mixed gas of oxygen gas and an inert gas is supplied from the gas storage unit while measuring the gas flow rate via a flow rate controller. Examples of the inert gas include one or a mixture of two or more gases selected from the group consisting of argon, helium, and nitrogen.

  These supplied gases are mixed at a predetermined ratio as necessary, formed into a plasma source gas alone or a mixed gas for plasma formation, and supplied to a plasma supply unit. The single or mixed gas is supplied to the plasma supply nozzle of the plasma supply means, and is supplied to the vicinity of the outer periphery of the pretreatment roller 70 where the supply port of the plasma supply nozzle is open. The nozzle opening is directed to the stretched plastic film 141 on the pretreatment roller 70, and is arranged and configured so that the oxygen plasma P can be uniformly diffused and supplied to the entire surface of the stretched plastic film 141. This makes it possible to perform uniform plasma pretreatment on a large area portion of the stretched plastic film 141.

  In order to set the transformation rate of the transition region of the aluminum oxide vapor-deposited film to 5% or more and 60% or less as described above, the oxygen plasma pretreatment includes a mixture ratio of oxygen gas and inert gas (oxygen gas / inert gas). Is preferably 1/1 or more, and may be 3 / 2.5 or more, or 3/2 or more. The mixing ratio of the oxygen gas to the inert gas (oxygen gas / inert gas) is preferably 6/1 or less, and may be 3/1 or less, or may be 5/2 or less. By setting the mixing ratio to be at least 1/1 and at most 6/1, the energy for forming a film of vapor-deposited aluminum on the plastic film is increased, and further at least 3/2 and at most 5/2, to form aluminum hydroxide. Are formed near the interface of the plastic film, that is, the transformation rate of the transition region is reduced. The range of the mixing ratio of the oxygen gas and the inert gas (oxygen gas / inert gas) can be determined by any combination of the above-described lower limit candidate value and upper limit candidate value.

  The electrode 71 functions as a counter electrode of the pretreatment roller 70. The supplied plasma raw material gas is excited by a potential difference due to a high frequency voltage, a low frequency voltage or the like supplied between the pretreatment roller 70, and the plasma P is generated and supplied.

  Specifically, the electrode 71 is provided with a plasma pretreatment roller as a plasma power source, applies an AC voltage having a frequency of 10 Hz to 2.5 GHz between the electrode 71 and the counter electrode, and performs input power control or impedance control. And a state in which an arbitrary voltage is applied to the plasma pre-treatment roller 70. The film forming apparatus 60 is provided with a power supply 82 capable of applying a bias voltage for making the oxygen plasma P capable of performing a process of physically or chemically modifying the surface physical properties of the stretched plastic film 141 to a positive potential.

Plasma intensity per unit area is preferably 50W · sec / m ² or more 8000W · sec / m ² or less. At 50 W · sec / m ² or less, the effect of the plasma pretreatment is not seen. At 8000 W · sec / m ² or more, the stretched plastic film 141 deteriorates due to plasma such as consumption, damage coloring, and firing of the stretched plastic film 141. Tends to happen. In particular, the plasma intensity per unit area is preferably 100 W · sec / m ² or more. Further, the plasma intensity per unit area is preferably 1000 W · sec / m ² or less, more preferably 500 W · sec / m ² or less, and may be 300 W · sec / m ² or less. By providing a bias voltage perpendicular to the stretched plastic film 141 and giving the above-described plasma intensity, the adhesion to the aluminum oxide deposited film can be stably improved. The range of the plasma intensity per unit area can be determined by any combination of the above-mentioned lower limit candidate value and upper limit candidate value.

  As the magnetic forming means 73, an insulating spacer and a base plate provided in a magnet case and a magnet provided on the base plate can be used. An insulating shield plate is provided on the magnet case, and electrodes can be attached to the insulating shield plate. The magnet case and the electrodes are electrically insulated, and even if the magnet case is installed and fixed in the decompression chamber 62, the electrodes can be electrically at a floating level. By providing the magnet, the reactivity in the vicinity of the surface of the stretched plastic film 141 is increased, and it is possible to form a favorable plasma pretreatment surface at a high speed.

  Preferably, the magnet is configured such that the magnetic flux density at the surface position of the stretched plastic film 141 is 10 gauss to 10000 gauss. When the magnetic flux density on the surface of the stretched plastic film 141 is 10 gauss or more, the reactivity in the vicinity of the surface of the stretched plastic film 141 can be sufficiently increased, and a good pretreatment surface can be formed at a high speed.

  Next, a film forming chamber 62C and a film forming process in the film forming chamber 62C will be described. The film forming apparatus 60 includes a film forming roller 75 disposed in the decompressed film forming chamber 62 </ b> C, and a target of the vapor deposition film forming unit 74 disposed to face the film forming roller 75. The film forming roller 75 winds and transports the stretched plastic film 141 with the processing surface of the stretched plastic film 141 pretreated by the plasma pretreatment device facing outward. In the film forming step, the target of the vapor deposition film forming means 74 is evaporated to form an aluminum oxide film on the surface of the stretched plastic film 141.

  The vapor deposition film forming means 74 is, for example, a resistance heating method, uses an aluminum metal wire with aluminum as an evaporation source, supplies oxygen to oxidize aluminum vapor, and deposits aluminum oxide on the surface of the stretched plastic film 141. A film is formed.

  The thickness of the transparent evaporation layer 142 including the aluminum oxide evaporation film formed as described above is preferably 3 nm or more, may be 8 nm or more, or may be 10 nm or more. Further, the thickness of the transparent evaporation layer 142 is preferably 50 nm or less, may be 30 nm or less, may be 20 nm or less, may be 15 nm or less, or may be 14 nm or less. The range of the thickness of the transparent vapor-deposited layer 142 can be determined by any combination of the above-described lower limit candidate value and upper limit candidate value. Within this range, barrier properties can be maintained. However, when the deposited film of aluminum oxide is very thin, it becomes difficult to calculate the transformation rate of the transition region by TOF-SIMS measurement.

  Next, a method of forming the gas barrier coating film 143 on the transparent evaporation layer 142 will be described. First, the above metal alkoxide, silane coupling agent, hydroxyl group-containing water-soluble resin, reaction accelerator (sol-gel method catalyst, acid, etc.), and organic solvent such as water, alcohol such as methyl alcohol, ethyl alcohol, isopropanol are used. By mixing, a coating agent for a gas barrier coating film composed of a resin composition is prepared.

  Next, the above-mentioned coating agent for a gas barrier coating film is applied on the transparent vapor-deposited layer 142 by an ordinary method, and dried. By this drying step, the condensation or co-condensation reaction further proceeds, and a coating film is formed. A plurality of coating films composed of two or more layers may be formed by repeating the above coating operation on the first coating film.

  Further, heat treatment is performed for 3 seconds to 10 minutes at a temperature in the range of 20 to 200 ° C., preferably 50 to 180 ° C., and a temperature not higher than the softening point of the resin constituting the base layer. Thus, the gas barrier coating film 143 made of the coating agent for a gas barrier coating film can be formed on the transparent evaporation layer 142. Thus, the vapor deposition film 14 having the stretched plastic film 141, the transparent vapor deposition layer 142, and the gas barrier coating film 143 can be manufactured.

(Preparation process of inner thermoplastic resin layer)
Next, a film constituting the inner thermoplastic resin layer 16 is prepared. When the inner thermoplastic resin layer 16 includes a plurality of layers, the film forming the inner thermoplastic resin layer 16 is, for example, a co-extruded film produced by co-extrusion.

(Lamination process of vapor deposition film and inner thermoplastic resin layer)
Next, the vapor deposition film 14 and the inner thermoplastic resin layer 16 are laminated via the adhesive layer 15 by a dry lamination method. In the dry lamination method, first, an adhesive composition is applied to one of two films to be laminated. Specifically, the adhesive composition is applied to either the gas barrier coating film 143 constituting the inner surface 14x of the vapor deposition film 14 or the inner thermoplastic resin layer 16. Preferably, the adhesive composition is applied to the gas barrier coating film 143. Subsequently, the applied adhesive composition is dried to evaporate the solvent. Thereafter, the two films are laminated via the dried adhesive composition. Subsequently, aging is performed for 72 hours or more in an environment of, for example, 30 ° C. or more in a state where the two laminated films are wound up. Thereby, as shown in FIG. 5, the first laminated body 20 having the stretched plastic film 141, the transparent vapor-deposited layer 142, the gas barrier coating film 143, the adhesive layer 15, and the inner thermoplastic resin layer 16 in order from the outside to the inside. Can be obtained. The inner surface 20x of the first laminate 20 is constituted by the inner thermoplastic resin layer 16, and the outer surface 20y is constituted by the stretched plastic film 141.

(Lamination process of first laminate and paper base material layer)
Next, the first laminate 20 and the paper base material layer 12 are laminated via the adhesive resin layer 13 by a sand lamination method. FIG. 6 is a diagram showing a laminating device 90 for laminating the first laminate 20 and the paper base material layer 12.

  In the laminating step using the laminating apparatus 90, first, the paper base material layer 12 is unwound from the first supply roll 91 as shown in FIG. Further, the first stacked body 20 is unwound from the second supply roll 92. Subsequently, the molten adhesive resin 13A for forming the adhesive resin layer 13 is extruded between the inner surface of the paper base material layer 12 and the stretched plastic film 141 of the first laminate 20. Thereby, the second laminate 25 in which the paper base layer 12 and the first laminate 20 are laminated via the adhesive resin layer 13 can be obtained. Note that, before extruding the molten adhesive resin 13A, an anchor coat layer may be provided on the inner surface of the paper base material layer 12. Thereby, the adhesion between the paper base layer 12 and the adhesive resin layer 13 can be improved. As the anchor coat layer, any resin having a heat resistance temperature of 135 ° C. or higher, for example, a layer made of a vinyl-modified resin, an epoxy resin, a urethane resin, a polyester resin, polyethyleneimine, or the like can be used.

  By the way, the higher the temperature of the molten adhesive resin 13A, the higher the temperature of the transparent vapor-deposited layer 142 of the vapor-deposited film 14 laminated by the sand lamination method. If the temperature of the transparent vapor deposition layer 142 is too high, the characteristics of the transparent vapor deposition layer 142 containing aluminum oxide may deteriorate. For example, it is conceivable that the transparent vapor-deposited layer 142 is peeled off from the stretched plastic film 141 or the gas barrier property of the vapor-deposited film 14 is reduced. Therefore, in order to suppress the deterioration of the characteristics of the transparent vapor-deposited layer 142, it is preferable that the temperature of the adhesive resin 13A in a molten state is low. For example, the temperature of the adhesive resin 13A in the molten state is preferably 330 ° C. or lower, more preferably 320 ° C. or lower.

  Preferably, the adhesive resin 13A and the adhesive resin layer 13 are, as described above, one or more selected from the group consisting of an epoxy group-containing compound, a silane group-containing compound, a carboxylic acid group-containing compound, and an acid anhydride-containing compound. It is a resin composition containing two or more compounds. Thereby, since the melting point of the adhesive resin 13A can be lowered, the temperature of the adhesive resin 13A in a molten state can be lowered. For this reason, it is possible to suppress deterioration of the characteristics of the transparent vapor-deposited layer 142 containing aluminum oxide during sand lamination. Further, it is possible to suppress the occurrence of pinholes in the adhesive resin layer 13, the vapor deposition film 14, the adhesive layer 15, the inner thermoplastic resin layer 16, and the like due to the evaporation of moisture in the paper base material layer 12. In addition, the resin composition containing one or more compounds selected from the group consisting of an epoxy group-containing compound, a silane group-containing compound, a carboxylic acid group-containing compound, and an acid anhydride-containing compound is a stretched plastic film 141. Has an adhesive property to the polyethylene constituting. For this reason, even when the anchor plastic layer is not provided on the stretched plastic film 141, the peeling of the adhesive resin layer 13 from the stretched plastic film 141 can be suppressed.

  Thereafter, the outer thermoplastic resin layer 11 may be formed on the outer surface of the second laminate 25 on the same line as the laminating apparatus 90. For example, as shown in FIG. 6, a molten thermoplastic resin 11A for forming the outer thermoplastic resin layer 11 is extruded onto the outer surface of the paper base material layer 12 of the second laminate 25. Thereby, the packaging material 10 for a paper container including the outer thermoplastic resin layer 11, the paper base layer 12, the adhesive resin layer 13, the vapor-deposited film 14, the adhesive layer 15, and the inner thermoplastic resin layer 16 can be obtained.

  Hereinafter, advantages provided by the paper container packaging material 10 in the present embodiment will be described.

  In the present embodiment, as described above, the vapor deposition film 14 and the inner thermoplastic resin layer 16 are bonded to each other by the dry lamination method with the gas barrier coating film 143 of the vapor deposition film 14 facing inward. Therefore, when the first laminate 20 including the vapor deposition film 14 and the paper base material layer 12 are adhered to each other by the sand lamination method, the heat of the molten adhesive resin 13A constituting the adhesive resin layer 13 causes the heat of the vapor deposition film 14 to become transparent. It is possible to suppress reaching the deposition layer 142. Thereby, it is possible to prevent the transparent vapor-deposited layer 142 from being peeled off from the stretched plastic film 141 due to heat, and the gas barrier properties of the vapor-deposited film 14 from being reduced. For this reason, even when aluminum oxide, which is more sensitive to heat than silicon oxide, is used as the transparent vapor-deposited layer 142, it is possible to suppress the barrier property of the vapor-deposited film 14 from being reduced. In addition, by using the transparent evaporation layer 142 of aluminum oxide, a physical evaporation method can be employed as a method for forming the transparent evaporation layer 142. Thereby, the productivity of the vapor deposition film 14 can be increased as compared with the case where the chemical vapor deposition method is adopted.

<Liquid paper container>
The paper container packaging material 10 is used as a material for forming a liquid paper container. Liquid paper containers have excellent barrier properties, and are used for alcoholic products such as sake, shochu, and wine, milk drinks such as milk, soft drinks such as orange juice and tea, and chemical products such as car wax, shampoo and detergents. It can be suitably used as a wrapping paper container for liquids in general. FIG. 7 is a perspective view showing an example of the liquid paper container 100 formed from the paper container packaging material 10.

  The liquid paper container 100 shown in FIG. 7 has a square cylindrical body 101 including a side surface, a square plate-shaped bottom 102, and an upper portion 103, and is a so-called Goebel top type container. The upper part 103 has a pair of inclined plates 104 facing each other, and a pair of folded portions 105 located between the pair of inclined plates 104 and folded between the inclined plates 104. Further, the pair of inclined plates 104 are adhered to each other by a margin 106 provided at each upper end. A spout may be attached to one of the pair of inclined plates 104, and the spout may be sealed with a cap. Further, a flat top type container may be formed.

  Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the description of the following examples unless it exceeds the gist.

[Example A1]
First, a 12 μm thick biomass-derived PET film was prepared as the stretched plastic film 141 of the vapor deposition film 14. The biomass-derived PET film is obtained by the following method.

After subjecting 83 parts by mass of terephthalic acid derived from fossil fuel and 62 parts by mass of ethylene glycol derived from biomass (manufactured by Indiaglycol Co.) to an esterification reaction by an ordinary straight-weight method, a condensation polymerization reaction was performed under reduced pressure. As a result, polyethylene terephthalate derived from biomass was obtained. Radiation carbon measurement of the obtained biomass-derived polyethylene terephthalate was performed, and the degree of biomass measured by radiocarbon (C14) was 31.25%.
The above-mentioned biomass-derived polyethylene terephthalate (60 parts by mass), fossil fuel-derived polyethylene terephthalate (30 parts by mass), and a masterbatch containing fossil fuel-derived polyethylene terephthalate (10 parts by mass) are supplied to an extruder, and a sheet is formed from a T die. To obtain an unstretched sheet. Next, the unstretched sheet was stretched in the longitudinal direction and then in the transverse direction to obtain a biaxially stretched PET film having a thickness of 12 μm. When the biomass degree of the obtained biaxially stretched PET film was measured, it was 18.8%.

Subsequently, the surface of the stretched plastic film 141 made of the above-described biaxially stretched PET film is subjected to oxygen plasma treatment using the above-described film forming apparatus 60 shown in FIG. Was formed to have a thickness of 12 nm.
(Oxygen plasma pretreatment conditions)
Plasma strength: 150W · sec / m ²
Mixing ratio of oxygen gas and inert gas: oxygen / argon = 2/1
・ Applied voltage between pretreatment drum and plasma supply nozzle: 340V
・ Pretreatment pressure: 3.8 Pa
(Aluminum oxide film formation conditions)
-Degree of vacuum: 8.1 × 10 ^-2 Pa
・ Transport speed: 400m / min
・ Oxygen gas supply: 20,000 sccm

Subsequently, a gas barrier coating film 143 was formed on the transparent evaporation layer 142. Specifically, first, 385 g of tetraethoxysilane as a metal alkoxide and glycide as a silane coupling agent were added to a solution prepared by mixing 385 g of water, 67 g of isopropyl alcohol, and 9.1 g of 0.5 N hydrochloric acid to adjust the pH to 2.2. Solution A was prepared by mixing 9.2 g of xylpropyltrimethoxysilane while cooling to 10 ° C.
As the water-soluble polymer, a solution B was prepared by mixing 14.7 g of polyvinyl alcohol having a degree of polymerization of 2400 with a saponification value of 99% or more, 324 g of water, and 17 g of isopropyl alcohol. The solution obtained by mixing the solution A and the solution B at a weight ratio of 6.5: 3.5 was used as a coating agent for a gas barrier coating film.
The coating agent for a gas barrier coating film prepared as described above was coated on the transparent evaporation layer 142 by a spin coating method.
Thereafter, a heat treatment was performed in an oven at 180 ° C. for 60 seconds to form a gas barrier coating film 143 having a thickness of about 400 nm on the transparent evaporation layer 142. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Example A2]
A transparent vapor deposition layer 142 is formed on a stretched plastic film 141 and a gas barrier coating film 143 is formed on the transparent vapor deposition layer 142 in the same manner as in Example A1 except that the thickness of the transparent vapor deposition layer 142 is set to 10 nm. Was formed. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Example A3]
A transparent vapor deposition layer 142 is formed on a stretched plastic film 141 and a gas barrier coating film 143 is formed on the transparent vapor deposition layer 142 in the same manner as in Example A1 except that the thickness of the transparent vapor deposition layer 142 is set to 14 nm. Was formed. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Reference Example A1]
A transparent vapor deposition layer 142 is formed on a stretched plastic film 141 and a gas barrier coating film 143 is formed on the transparent vapor deposition layer 142 in the same manner as in Example A1 except that the thickness of the transparent vapor deposition layer 142 is set to 7 nm. Was formed. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Reference Example A2]
A transparent vapor-deposited layer 142 was formed on the stretched plastic film 141 and a gas barrier coating 143 was formed on the transparent vapor-deposited layer 142 in the same manner as in Example A1, except that the oxygen plasma pretreatment was not performed. . In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Reference Example A3]
A transparent vapor-deposited layer 142 was formed on a stretched plastic film 141 in the same manner as in Example A1, except that the mixing ratio of oxygen gas and inert gas in the oxygen plasma treatment was changed to oxygen / argon = 4/1. Then, a gas barrier coating film 143 was formed on the transparent evaporation layer 142. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Reference Example A4]
A transparent vapor-deposited layer 142 is formed on a stretched plastic film 141 and a gas barrier coating film 143 is formed on the transparent vapor-deposited layer 142 in the same manner as in Example A1 except that the pretreatment pressure in the oxygen plasma treatment is set to 50 Pa. Was formed. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

[Reference Example A5]
A transparent vapor-deposited layer 142 is formed on a stretched plastic film 141 in the same manner as in Example A1, except that the plasma intensity in the oxygen plasma treatment is 1200 W · sec / m ² , and a gas barrier is formed on the transparent vapor-deposited layer 142. A conductive coating film 143 was formed. In this way, the vapor-deposited film 14 having the stretched plastic film 141, the transparent vapor-deposited layer 142, and the gas barrier coating film 143 was obtained.

  The denaturation rate was measured for the deposited films 14 of Examples A1 to A3 and Reference Examples A1 to A4 described above. Further, the color of the vapor-deposited film 14 of Example A1 and Reference Example A5 was measured. Further, for the film laminate including the vapor deposition films 14 of Examples A1 to A3 and Reference Examples A1 to A2, the measurement of the oxygen permeability and the measurement of the water vapor permeability were performed.

(Metamorphosis rate)
While repeating soft etching at a constant rate with a Cs (cesium) ion gun on the surface of the gas barrier coating film 143 of the vapor deposition film 14, gas barrier coating is performed using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The ions derived from the film 143, the ions derived from the transparent vapor-deposited layer 142, and the ions derived from the stretched plastic film 141 were measured. Thus, a graph was obtained in which the unit on the vertical axis (intensity) is the measured ion intensity and the unit on the horizontal axis (cycle) is the number of times of etching, as shown in FIG. 3 described above.

As a time-of-flight secondary ion mass spectrometer used in TOF-SIMS, ION TOF, TOF. The measurement was performed using SIMS5 under the following measurement conditions.
(TOFSIMS measurement conditions)
・ Primary ion type: Bi ₃ ++ (0.2 pA, 100 μs), measurement area: 150 × 150 μm ²
・ Et gun type: Cs (1 keV, 60 nA), Et area: 600 × 600 μm ² , Et rate: 3 sec / Cycle
In the analysis, among the ions derived from aluminum oxide, ions separated from other components were selected, those having a sufficient strength were selected, and the concentration distribution of the element-bonded Al ₂ O ₄ H was particularly improved. It is important to obtain a depth distribution that can be approximated. Considering these, Cs ions were selected as an ion gun for measuring ions derived from aluminum oxide to be measured.

Etching is performed from the outermost surface of the gas barrier coating film 143 using Cs, and the elemental bond at the interface between the gas barrier coating film 143, the transparent vapor deposition layer 142, and the stretched plastic film 141 and the elemental bond of the vapor deposition film are analyzed. , A graph of the measured elements and elemental bonds was obtained. In the graph, the position where the intensity of SiO ₂ (mass number 59.96), which is a constituent element of the gas barrier coating film 143, becomes half of the intensity in the gas barrier coating film 143, is defined by the gas barrier coating film 143 and the transparent evaporation layer 142. Interface. Further, a position where the strength of C ₆ (mass number 72.00), which is a constituent material of the stretched plastic film 141, becomes half of the strength of the stretched plastic film 141 is specified as an interface between the stretched plastic film 141 and the transparent evaporation layer 142. did. The distance between the two interfaces in the thickness direction was adopted as the thickness of the transparent vapor-deposited layer 142.

Next, a peak representing the measured element-bonded Al ₂ O ₄ H (mass number 118.93) was determined, and the region from the peak to the interface was defined as a transition region. However, when the component of the gas barrier coating film 143 is made of a material having the same mass number as Al ₂ O ₄ H (mass number 118.93), it is necessary to separate the waveform of 118.93.

When reactants AlSiO ₄ and hydroxide Al ₂ O ₄ H are generated at the interface between the gas barrier coating film 143 and the transparent vapor deposition layer 142, the reactant AlSiO ₄ and the hydroxide Al ₂ O ₄ H are formed at the interface between the stretched plastic film 141 and the transparent vapor deposition layer 142. Any Al ₂ O ₄ H present can be separated. As described above, the separation of the waveform can be appropriately dealt with according to the material of the gas barrier coating film 143.

  In the waveform separation, for example, a profile having a mass number of 118.93 obtained by TOF-SIMS is subjected to non-linear curve fitting using a Gaussian function, and separation of overlapping peaks is performed using the least squares method Levenberg Marquardt algorithm. It can be carried out.

The transformation rate of the transparent vapor-deposited layer 142 of the vapor-deposited films 14 of Examples A1 to A3 and Reference Examples A1 to A4 was calculated as (transition region thickness W ₁ / transparent vapor-deposited layer 142 thickness) × 100 (%). The results are shown in FIGS. 8A and 8B.

(Color)
Using a spectral colorimeter (manufactured by Konica Minolta, Inc. [model name: CM-700d]), one sample for measurement (stretched plastic film 141 / transparent vapor-deposited layer 142 / gas barrier coating film 143) produced from vapor-deposited film 14 ) In the L * a * b * color system, L * value, a * value and b * value were measured. The results are shown in FIGS. 8A and 8B.

(Oxygen permeability and water vapor permeability)
A non-stretched polypropylene film (CPP film) having a thickness of 70 μm and a stretched nylon film having a thickness of 15 μm were bonded to each other by a dry lamination method via a two-component curable polyurethane-based adhesive to prepare a laminate. Further, a two-component curable polyurethane-based adhesive is applied to the gas barrier coating film 143 side of the vapor-deposited films 14 of Examples A1 to A3 and Reference Examples A1 to A2, and is dried to form a coating on the gas barrier coating film 143. To form an adhesive layer. Subsequently, a laminate including the CPP film and the stretched nylon film and the vapor-deposited film 14 are attached to each other by a dry lamination method via an adhesive layer on the gas barrier coating film 143 of the vapor-deposited film 14, and a film for evaluation is formed. A laminate was produced. The layer configuration of the film laminate is expressed as follows from the outside to the inside.
PET film / transparent deposited layer / gas barrier coating / adhesive layer / stretched nylon film / adhesive layer / CPP film

  A sample for measuring oxygen permeability was prepared using the film laminate for evaluation. Specifically, first, the film laminate for evaluation was subjected to an aging treatment at 36 ° C. for 48 hours, and subsequently, the film laminate for evaluation was cut out to prepare a sample.

  Subsequently, each of the five types of measurement samples of Examples A1 to A3 and Reference Examples A1 to A2 was set such that the stretched plastic film 141 made of a PET film was on the oxygen supply side, and was heated at 23 ° C. and 90% RH. The oxygen permeability was measured under measurement conditions in an atmosphere according to JIS K 7126 B method. As the measuring device, an oxygen permeability measuring device (model name: OX-TRAN 2/21 manufactured by Modern Control (MOCON)) was used. The results are shown in FIGS. 8A and 8B.

(Water vapor permeability)
Water vapor permeability was measured using the same sample as in the case of measuring oxygen permeability. Specifically, each measurement sample was set so that the stretched plastic film 141 was on the sensor side, and the water vapor permeability was measured under the measurement conditions of 40 ° C. and 100% RH in accordance with JIS K 7126 B method. Was measured. As a measuring device, a water vapor permeability measuring device (a measuring device manufactured by MOCON [model name, PERMATRAN 3/33]) was used. The results are shown in FIGS. 8A and 8B.

As shown in FIG. 8A, in the vapor-deposited films 14 of Examples A1 to A3, the transformation rate of the transition region of the transparent vapor-deposited layer 142 is in the range of 5% or more and 60% or less, specifically, 10%. It was more than 25% or less. As the thickness of the transparent vapor-deposited layer 142 increased, the rate of denaturation tended to decrease. On the other hand, in the deposited film 14 of Reference Example A1 to A2, in order to elemental bond Al ₂ O4 _H peak could not be separated too small, metamorphic ratio of the transition region can not be calculated. In addition, in the deposited films 14 of Reference Examples A3 and A4, the plasma discharge was not stable, and the plasma pretreatment was not performed, so that the metamorphic rate in the transition region could not be calculated. From these facts, in order to produce the vapor-deposited film 14 such that the transformation rate of the transition region of the transparent vapor-deposited layer 142 is in the range of 5% to 60%, all of the following production conditions I to IV must be satisfied. Is preferred.
Manufacturing conditions I
The thickness of the transparent evaporation layer is 8 nm or more.
Manufacturing conditions II
The mixing ratio of the oxygen gas and the inert gas in the oxygen plasma treatment is 3 / 2.5 or more and 3/1 or less.
Manufacturing conditions III
The pretreatment pressure in the oxygen plasma treatment is 1 Pa or more and 20 Pa or less.
Manufacturing conditions IV
The plasma intensity in the oxygen plasma treatment is 100 W · sec / m ² or more and 500 W · sec / m ² or less.

  As shown in FIGS. 8A and 8B, the b * value of the vapor deposition film 14 of Reference Example A5 was larger than the b * value of the vapor deposition film 14 of Example A1. Moreover, in the vapor deposition film 14 of Reference Example A5, the appearance in which the stretched plastic film 141 was colored was visually confirmed. It is considered that the above-mentioned production conditions I to IV are also useful for suppressing coloring.

As shown in FIG. 8A, carried out in the film laminate comprising a vapor deposited film 14 of Example A1 to A3, the oxygen permeability is not more than ^{0.5cc / m 2 / 24hr / atm} , the water vapor permeability of 0.4 g / m ² / 24hr or less. On the other hand, as shown in FIG. 8B, in the sample of the film laminate comprising a vapor deposited film 14 of Example A2, the oxygen permeability was ^{0.8cc / m 2 / 24hr / atm} , the water vapor permeability of 1.1 g / m It was more than ² / 24hr. From these facts, it can be said that performing the oxygen plasma pretreatment is effective in maintaining the barrier property against gases such as oxygen and water vapor.

[Example B1]
As the vapor deposition film 14, a vapor deposition film 14 produced as in Example A1 was prepared.

  Further, a polyethylene film having a thickness of 60 μm was prepared as the inner thermoplastic resin layer 16. Subsequently, the surface of the vapor-deposited film 14 on the side of the gas barrier coating film 143 and the polyethylene film were laminated via the adhesive layer 15 by a dry lamination method. Thus, the first laminate 20 shown in FIG. 5 was obtained.

A liquid base paper (basis weight: 385 g / m ² ) was prepared as the paper base layer 12. Subsequently, after an anchor coat layer is formed on the inner surface of the liquid base paper, the liquid base paper and the first laminate 20 are bonded to each other by sand lamination using the above-described laminating apparatus 90 shown in FIG. They were laminated via a resin layer 13. Specifically, the molten adhesive resin constituting the adhesive resin layer 13 was extruded at a temperature of 320 ° C. and a thickness of 20 μm between the base paper for liquid and the stretched plastic film 141 of the first laminate 20. As the adhesive resin, an ethylene-methacrylic acid copolymer (AN4228C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was used.

  Subsequently, after an anchor coat layer was formed on the outer surface of the base paper for liquid, a polyethylene resin in a molten state was extruded to form an outer thermoplastic resin layer 11. Thus, the packaging material 10 for a paper container shown in FIG. 1 was obtained.

The layer configuration of the paper container packaging material 10 of the present embodiment is expressed as follows.
PE25 / AC / Paper / AC / EMAA20 / PET12 / Evaporation / Barrier / DL / PEF60
“PE” means a polyethylene layer formed by extrusion. “AC” means an anchor coat layer. "Paper" means a paper substrate layer. “EMAA” means an adhesive resin layer made of an ethylene-acrylic acid copolymer. “PET” means PET film. “Evaporation” means an aluminum oxide film. "Barrier" means a gas barrier coating film. “DL” means an adhesive layer. "PEF" means polyethylene film. The numbers refer to the thickness of the layer (unit: μm).

[Example B2]
Except that an ethylene-methacrylic acid copolymer (AN4228C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was extruded at a temperature of 320 ° C. and a thickness of 35 μm to form the adhesive resin layer 13, the same as in Example B1, A packaging material 10 for a paper container was produced.

The layer configuration of the paper container packaging material 10 of the present embodiment is expressed as follows.
PE25 / AC / Paper / AC / EMAA35 / PET12 / Evaporation / Barrier / DL / PEF60

[Example B3]
Example B1 Except for forming an adhesive resin layer 13 by extruding an adhesive resin having a density of 0.919 g / cm ³ and an MFR of 8.0 g / 10 minutes containing silane groups in polyethylene at a temperature of 320 ° C. and a thickness of 20 μm, In the same manner as in the above case, a packaging material 10 for a paper container was produced.

The layer configuration of the paper container packaging material 10 of the present embodiment is expressed as follows.
PE25 / AC / paper / AC / silane PE20 / PET12 / deposition / barrier / DL / PEF60
“Silane PE” means a polyethylene layer containing silane groups formed by extrusion.

[Example B4]
Except that the adhesive resin layer 13 was formed by extruding an adhesive resin having a density of 0.919 g / cm ³ and MFR 8.0 g / 10 minutes containing silane groups in polyethylene at a temperature of 320 ° C. and a thickness of 35 μm. In the same manner as in the case of B3, a packaging material 10 for a paper container was produced.

The layer configuration of the paper container packaging material 10 of the present embodiment is expressed as follows.
PE25 / AC / paper / AC / silane PE35 / PET12 / deposition / barrier / DL / PEF60

[Comparative Example B1]
The thickness of the polyethylene film of the inner thermoplastic resin layer 16 was set to 40 μm, and the vapor-deposited film 14 and the polyethylene film of the inner thermoplastic resin layer 16 were bonded by sand lamination using polyethylene extruded at a thickness of 20 μm. Except for the above, a first laminate 20 was produced in the same manner as in Example B1. The same procedure as in Example B1 was conducted except that an ethylene-acrylic acid copolymer (AN4228C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was extruded at a temperature of 320 ° C. and a thickness of 10 μm to form the adhesive resin layer 13. Thus, the paper base layer 12 and the deposition film 14 were laminated. Further, in the same manner as in Example B1, an outer thermoplastic resin layer 11 was formed on the outer surface of the paper base material layer 12 to obtain a packaging material 10 for a paper container.

The layer configuration of the packaging material for paper containers 10 of this comparative example is expressed as follows.
PE25 / AC / Paper / AC / EMAA10 / PET12 / Evaporation / Barrier / AC / PE20 / PEF40

[Comparative Example B2]
Except that the ethylene-acrylic acid copolymer (AN4228C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was extruded at a temperature of 320 ° C. and a thickness of 20 μm to form the adhesive resin layer 13, the same as in the case of Comparative Example B1, A packaging material 10 for a paper container was produced.

The layer configuration of the packaging material for paper containers 10 of this comparative example is expressed as follows.
PE25 / AC / Paper / AC / EMAA20 / PET12 / Evaporation / Barrier / AC / PE20 / PEF40

[Comparative Example B3]
A paper container packaging material 10 was prepared in the same manner as in Comparative Example B1, except that low-density polyethylene LC520 manufactured by Japan Polyethylene Corporation was extruded at a temperature of 320 ° C. and a thickness of 20 μm to form the adhesive resin layer 13. did.

The layer configuration of the packaging material for paper containers 10 of this comparative example is expressed as follows.
PE25 / AC / Paper / AC / PE20 / PET12 / Evaporation / Barrier / AC / PE20 / PEF40

[Comparative Example B4]
Except that an ethylene-acrylic acid copolymer (AN4228C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was extruded at a temperature of 320 ° C. and a thickness of 60 μm to form an adhesive resin layer 13, paper was prepared in the same manner as in Example B1. A container packaging material 10 was produced.

The layer configuration of the packaging material for paper containers 10 of this comparative example is expressed as follows.
PE25 / AC / Paper / AC / EMAA60 / PET12 / Evaporation / Barrier / DL / PEF60

  FIG. 9 shows the layer configurations of the packaging materials 10 for paper containers of Examples B1 to B4 and Comparative Examples B1 to B4.

  For the packaging materials 10 for paper containers of Examples B1 to B4 and Comparative Examples B1 to B4, the measurement of the peel strength, the measurement of the water vapor transmission rate, the measurement of the oxygen transmission rate, and the evaluation of the sealing property of the filling machine were performed. .

(Peel strength)
The delamination strength (N / 15 mm) between the adhesive resin layer 13 and the vapor-deposited film 14 was measured for each of the packaging materials 10 for paper containers of Examples B1 to B4 and Comparative Examples B1 to B4. Specifically, a 90 ° peel test was performed at a peel speed of 50 mm / min using a tensile tester (Tensilon universal tester RTC1310A, manufactured by Orientec). The results are shown in FIG.

(Water vapor permeability)
For each of the paper container packaging materials 10 of Examples B1 to B4 and Comparative Examples B1 to B4, at a temperature of 40 ° C. and a humidity of 100% RH, a measuring machine [model name, PERMATRAN, manufactured by MOCON, USA) ], The water vapor permeability was measured in accordance with JIS K 7129 (sample number N = 10). The results are shown in FIG.

(Oxygen permeability)
For each of the packaging materials 10 for paper containers of Examples B1 to B4 and Comparative Examples B1 to B4, at a temperature of 23 ° C. and a humidity of 90% RH, a measuring machine [model name, OXTRAN, manufactured by MOCON, USA) ], The oxygen permeability was measured in accordance with JIS K 7126 (sample number N = 10). The results are shown in FIG.

(Sealability of filling machine)
A liquid paper container was produced by molding and heat sealing each of the paper container packaging materials 10 of Examples B1 to B4 and Comparative Examples B1 to B4. The temperature of the heat seal was 260 ° C, 280 ° C, 300 ° C, 320 ° C or 340 ° C. Further, the obtained liquid paper container was filled with water, and whether or not water leakage occurred was evaluated. In addition, it was visually confirmed whether or not a pinhole was generated at the heat-sealed portion. The results are shown in FIG. In FIG. 11, "good" means that no water leakage occurred and no pinhole was generated at the heat-sealed portion. "Not good" means that no water leakage occurred, but a pinhole occurred at the heat-sealed portion. Further, “bad” means that delamination has occurred in the paper container packaging material 10 when the paper container packaging material 10 is molded and heat-sealed.

  As can be seen from the comparison between Examples B1 to B4 and Comparative Example B3, the use of an ethylene-acrylic acid copolymer or a silane group-containing compound as the adhesive resin layer 13 could ensure the peel strength. Specifically, the peel strength was able to be 2.8 N / 15 mm or more.

As can be seen from the comparison between Examples B1 to B4 and Comparative Examples B1 to B3, the vapor barrier film 14 and the inner thermoplastic resin layer 16 are bonded not by the sand lamination method but by the dry lamination method, whereby the water vapor barrier property and the oxygen barrier property are improved. Nature was able to be secured. Specifically, the water vapor transmission rate and the oxygen transmission rate could be reduced to 1 cc / m ² · day or less. Further, as can be seen from the comparison between Examples B1 to B4 and Comparative Example B4, by setting the thickness of the adhesive resin layer 13 to 35 μm or less, the water vapor barrier property and the oxygen barrier property could be secured.

  As can be seen from the comparison between Examples B1 and B2 and Comparative Example B1, by setting the thickness of the adhesive resin layer 13 made of the ethylene-acrylic acid copolymer to 20 μm or more, it is possible to suppress the occurrence of pinholes in the heat-sealed portion. We were able to.

DESCRIPTION OF SYMBOLS 10 Packaging material for paper containers 11 Outer thermoplastic resin layer 12 Paper base layer 13 Adhesive resin layer 14 Deposition film 141 Stretched plastic film 142 Transparent vapor deposition layer 143 Gas barrier coating film 15 Adhesive layer 16 Inner thermoplastic resin layer 161 First Layer 162 Second layer 163 Third layer 20 Laminated body 90 Laminating device 91 First supply roll 92 Second supply roll 100 Liquid paper container

Claims (8)

In order from the outside to the inside, at least, an outer thermoplastic resin layer, a paper base layer, an adhesive resin layer, a vapor-deposited film, an adhesive layer, and an inner thermoplastic resin layer, a packaging material for a paper container comprising:
The deposited film, a stretched plastic film, provided on the inner surface of the stretched plastic film, a transparent deposition layer containing aluminum oxide, and a gas barrier coating film provided on the transparent deposition layer, Have
A packaging material for paper containers, wherein the stretched plastic film of the vapor-deposited film contains a biomass-derived polyester.   The packaging material for a paper container according to claim 1, wherein the gas barrier coating film of the vapor-deposited film is in contact with the adhesive layer.   The adhesive resin layer is a resin composition containing one or more compounds selected from the group consisting of an epoxy group-containing compound, a silane group-containing compound, a carboxylic acid group-containing compound, and an acid anhydride-containing compound. The packaging material for paper containers according to claim 1 or 2.   The packaging material for a paper container according to any one of claims 1 to 3, wherein the adhesive resin layer is in contact with an outer surface of the stretched plastic film.   The packaging material for a paper container according to any one of claims 1 to 4, wherein a thickness of the adhesive resin layer is 15 µm or more and 40 µm or less. The transparent deposition layer includes a transition region,
The transition region is detected by performing etching on the vapor-deposited film from the gas barrier coating film side using time-of-flight secondary ion mass spectrometry (TOF-SIMS). An area between a position of a peak of Al ₂ O ₄ H and an interface between the transparent vapor-deposited layer and the stretched plastic film,
The packaging material for paper containers according to any one of claims 1 to 5, wherein a ratio of a thickness of the transition region to a thickness of the transparent vapor-deposited layer is 5% or more and 60% or less.   The packaging material for paper containers according to any one of claims 1 to 6, wherein the outer thermoplastic resin layer or the inner thermoplastic resin layer contains biomass-derived polyethylene.   A liquid paper container comprising the packaging material for a paper container according to any one of claims 1 to 7.