Method for manufacturing packaging material and method for manufacturing package

Abstract

To suppress, even when a content to be packaged is a highly permeable content, a decrease in laminate strength due to an influence thereof.SOLUTION: A production method of a packaging material includes: forming a gas barrier vapor-deposited layer comprising an inorganic compound on a substrate; forming, on the gas barrier vapor-deposited layer, a gas barrier coating layer formed by using a composition comprising one or more compounds selected from a metal alkoxide, a hydrolysate of metal alkoxide and a polymer of metal alkoxide, and a hydroxy group-containing high polymer compound; applying an aqueous medium coating solution comprising an acid-modified polyolefin resin and a silane coupling agent onto the gas barrier coating layer, and heating and drying the coating layer to form an adhesive layer; and laminating a polyolefin sealant layer on the adhesive layer by an extrusion lamination method at an extrusion temperature of 250°C-330°C. An applied amount of the adhesive layer after drying is 0.1-2.0 g / m2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a packaging material and a package. Manufacturing method This application claims priority to Japanese Patent Application No. 2019-055594, filed on March 22, 2019, the contents of which are incorporated by reference. [Background technology]

[0002] For example, packaging materials for packaging solid, powder, or liquid contents such as food, medicine, or toiletries are produced by laminating a heat-sealable film (hereinafter referred to as a sealant layer) such as polyethylene or polypropylene onto a substrate of various stretched films such as polyester, polyamide, or polypropylene, or onto a substrate of metal foil such as aluminum foil, using, for example, a polyurethane adhesive, etc. In particular, when gas barrier properties are required for the packaging material, a layer with excellent gas barrier properties such as an inorganic vapor-deposited film substrate layer or an ethylene-vinyl alcohol copolymer is provided on the packaging material. The contents to be packaged in the packaging material may be made of various materials, and depending on the properties of the contents, they may have various effects on the packaging material.

[0003] For example, Patent Document 1 describes a gas barrier packaging material that can prevent coloring of the packaging material even when a coloring substance is used as the content. This gas barrier packaging material is composed of a substrate layer, an adhesive layer, a gas barrier layer, an anchor coat layer, and a polyolefin resin layer laminated in this order. The anchor coat layer of this laminate is formed by applying and drying an aqueous dispersion in which a polyolefin copolymer resin containing an unsaturated carboxylic acid or its anhydride in the range of 0.01% by mass to 5% by mass is dispersed to a number average particle size of 1 μm or less, substantially free of a non-volatile water-imparting aid. Furthermore, the polyolefin resin layer is laminated while performing ozone treatment on the surface of the melt-extruded polyolefin resin that contacts the anchor coat layer.

[0004] For example, Patent Document 2 describes a packaging bag for alcohol-containing products that can safely seal and package liquids with an alcohol concentration of 50% by mass or more, or products impregnated with such liquids. This packaging bag for alcohol-containing products is formed by laminating a base layer, an adhesive layer, a barrier layer, an anchor coat layer, and a polyolefin resin layer in this order. The barrier layer of this laminate is aluminum foil or a vapor-deposited film obtained by vapor-depositing aluminum oxide or silicon oxide onto a base film. The anchor coat layer is formed by applying an aqueous dispersion formed by dispersing a polyolefin polymer resin containing 0.01% by mass to 5% by mass of an unsaturated carboxylic acid or its anhydride to a number average particle size of 1 μm or less and substantially not containing a non-volatile water-imparting aid, followed by heating and drying. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent No. 5359079 [Patent Document 2] Japanese Patent No. 5415670 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional packaging materials and packages have the following problems. The contents packaged in packaging materials may include, for example, acidic or alkaline substances, fragrances, surfactants, high-boiling organic solvents, medicinal ingredients, alcohol, volatile substances, etc. Such contents may cause a decrease in the lamination strength of the packaging material laminate or may cause the laminate to peel off, and are therefore called highly permeable contents. For example, highly permeable contents pass through packaging materials and swell and dissolve the polyurethane adhesive used for lamination, resulting in a problem of reduced adhesive performance of the polyurethane adhesive. In particular, when a barrier substrate such as aluminum foil or inorganic vapor deposition film substrate is used as part of the packaging material, the adhesive performance of the polyurethane adhesive is likely to be reduced. The reason for this is thought to be that the highly penetrating contents that pass through the sealant layer are trapped by the barrier substrate and accumulate in the polyurethane-based adhesive. In contrast, the technologies described in Patent Documents 1 and 2 are characterized by the fact that they do not cause swelling or dissolution, as occurs when urethane adhesives are used, even when contents contain coloring substances or alcohol. However, the technologies described in Patent Documents 1 and 2 are limited to substrates suitable for obtaining adhesive strength, and the adhesive strength with inorganic vapor deposition film substrates is particularly weak, so even if swelling or dissolution does not occur, they are not suitable for packaging materials that contain highly permeable contents.

[0007] The present invention has been made in view of the above-mentioned problems, and aims to provide a packaging material and a package using an inorganic vapor-deposited film substrate, in which even if the contents to be packaged are highly permeable, a decrease in laminate strength due to the influence of the highly permeable contents is suppressed. [Means for solving the problem]

[0008] In order to solve the above problems, the packaging material of the first aspect of the present invention comprises a substrate made of a polymer resin composition, a gas barrier vapor deposition layer made of an inorganic compound, a gas barrier coating layer formed using a composition containing at least one compound selected from metal alkoxides, hydrolysates of metal alkoxides, and polymers of metal alkoxides, and a hydroxy group-containing polymer compound, an adhesive layer formed in contact with the gas barrier coating layer and containing an acid-modified polyolefin resin and a silane coupling agent, and a polyolefin sealant layer, laminated in this order.

[0009] In the packaging material of the first aspect, the gas barrier coating layer may be a composition formed by using a composition containing at least one compound selected from metal alkoxides, hydrolysates of metal alkoxides, and polymers of metal alkoxides, and a hydroxy group-containing polymer compound, and further using at least one compound selected from isocyanate derivatives, hydrolysates of isocyanate derivatives, and polymers of isocyanate derivatives.

[0010] In the packaging material of the first aspect, the adhesive layer may contain 0.2 parts by mass or more and 2.0 parts by mass or less of the silane coupling agent per 100 parts by mass of the acid-modified polyolefin resin.

[0011] In the packaging material of the first aspect, the silane coupling agent may be an epoxy-based silane coupling agent.

[0012] In the packaging material of the first aspect, the epoxy-based silane coupling agent may be at least one compound selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0013] In the packaging material of the first aspect, the gas barrier vapor-deposited layer may contain at least one of silicon oxide and aluminum oxide.

[0014] In the packaging material of the first aspect, the metal alkoxide may be made of at least one compound selected from the group consisting of tetraethoxysilane, tetramethoxysilane, and triisopropoxyaluminum.

[0015] In the packaging material of the first aspect, the coating amount of the adhesive layer after drying is 0.1 to 2.0 g / m 2 may be.

[0016] The packaging material of the first aspect may further comprise a paper sheet.

[0017] A packaging body according to a second aspect of the present invention comprises a packaging bag formed from the packaging material according to the first aspect, and a highly permeable content contained in the packaging bag and including a highly permeable material.

[0018] Another packaging body of the present invention comprises a paper container for liquid formed from the packaging material of the first aspect described above, which comprises a paper sheet, and a highly permeable content contained in the paper container for liquid, which includes a highly permeable material.

[0019] A third aspect of the present invention is a method for producing the packaging material according to the first aspect. In this method, a polyolefin sealant layer is laminated by extrusion lamination at an extrusion temperature of 250°C to 330°C. [Effects of the Invention]

[0020] According to the packaging material and package of the present invention, even if the contents to be packaged are highly permeable contents, it is possible to suppress a decrease in laminate strength due to the influence of the highly permeable contents. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic front view showing an example of a packaging body according to a first embodiment of the present invention. FIG. [Figure 2] 1 is a schematic cross-sectional view showing an example of a packaging material according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a schematic cross-sectional view of a packaging material according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a schematic cross-sectional view showing a modified example of the packaging material. [Figure 5] 10A and 10B are diagrams showing an example of a paper container for liquid formed from the same packaging material. DETAILED DESCRIPTION OF THE INVENTION

[0022] A packaging body and a packaging material according to a first embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic front view showing an example of a packaging body according to the present embodiment, and Fig. 2 is a schematic cross-sectional view showing an example of a packaging material according to the present embodiment.

[0023] As shown in FIG. 1, a packaging body 3 of this embodiment includes a packaging bag 1 and a highly permeable content 2. In the example shown in Fig. 1, the packaging bag 1 is a flat bag in which a first laminate film 1a and a second laminate film 1b are heat-sealed. The shape of the packaging bag 1 when viewed from the front is, for example, substantially rectangular. In Fig. 1, the first laminate film 1a is arranged on the front side of the illustration. The second laminate film 1b has an outer shape similar to that of the first laminate film 1a and is arranged on the back side of the first laminate film 1a, overlapping with the first laminate film 1a. A spout 1d is formed at a corner of the packaging bag 1, forming a flow path for pouring out the highly permeable contents 2 when the packaging bag 1 is opened. The spout 1d may be embossed, such as in a linear shape, as needed. A pouring pipe (not shown) may be provided inside the spout 1d as needed. The spout 1d may be provided with a notch for opening, a fragile part that serves as an opening assist line, or the like, as needed.

[0024] The package 3 is produced by injecting the highly permeable contents 2 into a bag formed by heat-sealing three sides of the first laminate film 1a and the second laminate film 1b, and then heat-sealing the opening. However, the type of packaging bag 1 is not limited to a flat bag as long as it can accommodate the highly permeable contents 2 described below. For example, the packaging bag 1 used in the package 3 may be a gusset pouch, a standing pouch, or the like.

[0025] The highly permeable contents 2 in this embodiment are contents containing an appropriate highly permeable material. The highly permeable material is a substance that has a high permeability to packaging materials. For example, when a highly permeable material is contained inside a packaging bag made of a laminated film, the highly permeable material may permeate from the inner layer to the outer layer of the laminated film. The highly permeable material that has permeated the laminated film may deteriorate the laminated film. For example, the highly permeable material that has permeated the laminated film may corrode the film substrate of the laminated film or reduce the adhesive strength between the layers of the laminated film. Examples of such highly permeable materials include acidic substances, alkaline substances, fragrances, surfactants, high-boiling organic solvents, medicinal ingredients, alcohol, and volatile substances.

[0026] However, instead of the highly permeable contents 2, the packaging bag 1 may contain contents that do not contain a highly permeable material. Therefore, examples of contents that can be accommodated in the packaging bag 1 include edible agents, daily necessities, pharmaceutical agents, industrial agents, reagents, and the like. Examples of edible agents include beverages such as milk, tea, coffee, cooking oil, juice, soft drinks, carbonated drinks, and alcohol, as well as cooking agents such as seasonings, cooking oil, vinegar, dressings, spice powders, and curry powder. For example, household products include detergents, toothpastes, hair tonics, hair care products, shampoos, rinses, perm solutions, cosmetics, bath additives, air fresheners, toiletries, and floor wax. For example, medicinal agents include medicines such as mouthwashes, patches, and disinfectants. For example, industrial agents include reagents, engine oil, motor oil, silicone oil, and the like. For example, the reagents include l-menthol, d-limonene, methyl salicylate, camphor, and the like.

[0027] The first laminate film 1a and the second laminate film 1b are both made of the laminate film 4, which is the packaging material of this embodiment. As shown in FIG. 2, the laminated film 4 is composed of at least a substrate 4A, a gas barrier vapor deposition layer 4B, a gas barrier coating layer 4C, an adhesive layer 4D, and a polyolefin sealant layer 4E laminated in this order. The laminate film 4 may optionally include layered portions other than the substrate 4A, the gas barrier vapor deposition layer 4B, the gas barrier coating layer 4C, the adhesive layer 4D, and the polyolefin sealant layer 4E. For example, the laminate film 4 may include a surface protection layer for improving surface strength, a printed layer on which an image is formed, a coating layer for improving adhesive strength between layers, and the like.

[0028] The substrate 4A is a film material made of an appropriate polymer resin composition. Examples of polymer resin materials that are the main component of the substrate 4A include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene and polypropylene, polystyrene resins, polyamide resins such as 6,6-nylon, polycarbonate resins, polyacrylonitrile resins, and polyimide resins. The substrate 4A may be made of a stretched film material or an unstretched film material, but it is particularly preferable to use a biaxially stretched film material as the substrate 4A. It is more preferable to use a polyamide film, a polyester film, or a polypropylene film as the base material 4A from the viewpoints of moisture resistance, suitability for filling, ease of opening, impact resistance, texture, disposability, etc. It is particularly preferable to use a polyester film as the base material 4A.

[0029] The substrate 4A may contain various well-known additives, such as a stabilizer, an antistatic agent, a plasticizer, a lubricant, and an antioxidant, if necessary.

[0030] The thickness of the substrate 4A is not particularly limited. From the viewpoint of processability and filling suitability, the thickness of the substrate 4A may be 3 μm or more and 200 μm or less. The thickness of the substrate 4A is more preferably 6 μm or more and 30 μm or less.

[0031] To improve the adhesion between the substrate 4A and the gas barrier vapor-deposited layer 4B (described later), the surface of the substrate 4A may be subjected to a pretreatment such as a corona treatment, a plasma treatment, or an ozone treatment. Furthermore, the surface of the substrate 4A may be subjected to a chemical treatment, a solvent treatment, or the like. In particular, plasma treatment is more preferable for the substrate 4A, since plasma treatment will result in strong adhesion between the gas barrier vapor-deposited layer 4B (described later) and the substrate 4A.

[0032] Similarly, a coating layer may be provided to improve adhesion between the substrate 4A and the gas barrier vapor-deposited layer 4B described below. Materials for the coating layer include at least one compound selected from the group consisting of organic compounds obtained by the reaction of polyols with isocyanate compounds, organic compounds having a urea bond obtained by the reaction of a polyisocyanate compound with water, polyethyleneimine and its derivatives, polyolefin emulsions, polyimide, melamine, phenol, inorganic silica, and organic silane compounds.

[0033] Examples of polyols include acrylic polyol, polyvinyl acetal, polystyrene polyol, and polyurethane polyol.

[0034] As the isocyanate compound, monomers such as aromatic tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), and aliphatic xylene diisocyanate (XDI) and hexane diisocyanate (HMDI), as well as their polymers and derivatives, can be used alone or in mixtures, and high adhesion to the substrate 4A and gas barrier vapor deposition layer 4B can be obtained due to the urethane bond formed by the reaction between the acrylic polyol and the isocyanate compound.

[0035] Examples of inorganic silica include organically modified colloidal silica. The organic silane compound includes a silane coupling agent and a hydrolyzate thereof.

[0036] A particularly preferred material for the coating layer is a composition containing a trifunctional organosilane represented by the general formula R'Si(OR)3 (R': alkyl group, vinyl group, glycidoxypropyl group, etc., R: alkyl group, etc.) or a hydrolyzate of the trifunctional organosilane, together with a composite of an acrylic polyol and an isocyanate compound. Examples of the trifunctional organosilane include ethyltrimethoxysilane, vinyltrimethoxysilane, and glycidoxypropyltrimethoxysilane. Among these, glycidoxytrimethoxysilane and epoxycyclohexylethyltrimethoxysilane, which contain an epoxy group in R', are particularly preferred, as they provide particularly high adhesion between the substrate 4A and the gas barrier vapor deposition layer 4B. The hydrolyzate can be obtained by known methods, such as hydrolysis by adding an acid or alkali to the trifunctional organosilane.

[0037] Various additives, such as curing accelerators, antioxidants, leveling agents, flow control agents, catalysts, crosslinking reaction accelerators, and fillers, can also be added to these coating materials. The thickness of the coating layer is preferably in the range of 0.01 μm to 2.0 μm. If the thickness is thinner than 0.01 μm, it is difficult to obtain a uniform coating film, and adhesion may decrease. Furthermore, if the thickness exceeds 2.0 μm, the coating film is too thick to maintain flexibility, and external factors may cause cracks in the coating film, which is undesirable. A thickness in the range of 0.05 μm to 0.5 μm is particularly preferable. The coating layer can be formed by, for example, a known application method such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, or spray coating, or a known printing method such as offset printing, gravure printing, or silk screen printing. Drying conditions may be those generally used.

[0038] The gas-barrier vapor-deposited layer 4B is made of an inorganic compound having gas-barrier properties. In the example shown in Fig. 2, the gas-barrier vapor-deposited layer 4B is laminated on a substrate 4A. The inorganic compounds include oxides, nitrides, and fluorides of silicon, aluminum, titanium, zirconium, tin, magnesium, etc., and may be a single substance or a mixture of multiple substances. Aluminum oxide or silicon oxide is particularly preferred for the gas barrier vapor deposition layer 4B, as these materials have excellent transparency and water resistance to boiling and retort sterilization treatments while maintaining gas barrier properties, making them suitable for the gas barrier vapor deposition layer 4B. The degree of oxidation of the vapor-deposited layer of aluminum oxide or silicon oxide does not need to be limited as long as the gas barrier properties, transparency, etc. are not impaired.

[0039] The thickness of the gas barrier vapor-deposited layer 4B is preferably 5 nm or more and 300 nm or less. If the thickness exceeds 300 nm, flexibility may decrease and cracks may easily occur, so the thickness is more preferably 5 nm or more and 300 nm or less.

[0040] Methods for forming the gas barrier vapor deposition layer 4B include vacuum vapor deposition methods such as resistance heating, induction heating, and EB heating, as well as reactive vapor deposition, reactive sputtering, reactive ion plating, and plasma vapor deposition (CVD), which form a film in the presence of a mixed gas of oxygen, carbon dioxide, and an inert gas.

[0041] The gas barrier coating layer 4C is a layer formed by coating the gas barrier vapor deposition layer 4B with a coating agent prepared by mixing an aqueous solution containing a hydroxyl group-containing polymer compound or a water and alcohol mixed solution with at least one selected from a metal alkoxide, or a pre-hydrolyzed metal alkoxide and a polymer of a metal alkoxide, followed by heating and drying.

[0042] Examples of the hydroxyl group-containing polymer compound used in the gas barrier coating layer 4C include polyvinyl alcohol, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, ethylene-vinyl alcohol copolymer, etc. Polyvinyl alcohol (hereinafter referred to as PVA) is preferred because of its good gas barrier properties.

[0043] The metal alkoxide used in the gas barrier coating layer 4C is represented by the general formula: M(OR) n (M: metal such as Si, Ti, Al, Zr, etc., R: alkyl group such as CH3, C2H5). Specific examples include compounds of the general formula Si(OR 1 ) 4 [General formula (1)] (wherein R 1 Tetraethoxysilane [Si(OC2H5)4], tetramethoxysilane [Si(OCH3)4], triisopropoxyaluminum [Al(O-2'-C3H7)3], etc., represented by the formula (wherein represents CH3, C2H5, or C2H4OCH3), are preferred because they are relatively stable in aqueous solvents after hydrolysis. Hydrolyzates can be obtained by known methods, such as adding an acid or alkali to a metal alkoxide to carry out hydrolysis.

[0044] The gas barrier coating layer 4C is formed from a coating agent prepared by mixing at least one selected from a metal alkoxide, a hydrolyzed metal alkoxide, and a polymer of a metal alkoxide with an aqueous solution or a water and alcohol mixture containing a hydroxyl group-containing polymeric compound. The metal alkoxide is a highly reactive inorganic component that undergoes hydrolysis and polycondensation in the solution to form a chain or three-dimensional dendritic polymer, and further polymerization proceeds as the solvent evaporates during drying and heating.

[0045] Strong hydrogen bonds are formed between the hydroxy groups of the hydroxy group-containing polymer compound and the hydroxy groups of the hydrolyzed metal alkoxide, and when the metal oxide undergoes condensation polymerization, the hydroxy group-containing polymer compound disperses among the metal oxides, resulting in a film structure similar to a ceramic film, and the gas barrier coating layer 4C itself exhibits high gas barrier properties.

[0046] In addition, when the gas barrier coating layer 4C is required to have water resistance and heat resistance for boiling sterilization heat treatment, high-temperature and high-pressure sterilization treatment, etc., a coating agent is prepared by mixing at least one selected from the metal alkoxide, pre-hydrolyzed metal alkoxide and polymer of metal alkoxide with an aqueous solution or a water-alcohol mixed solution containing the hydroxy group-containing polymer compound, and further mixing a compound represented by the general formula (R 2 Si(OR 3 )3) n [General formula (2)] (wherein, in general formula (2), R 2 is an organic functional group, R 3 The silicon compound may be formed by coating a solution obtained by adding and mixing at least one compound selected from silicon compounds represented by the formula (III) (wherein C represents CH3, C2H5, or C2H4OCH3), their hydrolysates, and their polymers, followed by heating and drying.

[0047] The organic functional group R in general formula (2) 2is more preferably selected from non-aqueous functional groups such as vinyl, epoxy, methacryloxy, ureido, and isocyanate, etc. The non-aqueous functional groups further improve water resistance because the functional groups are hydrophobic.

[0048] It is preferable that the silicon compound represented by the general formula (2) is a composition formed using at least one compound selected from an isocyanate derivative, a hydrolyzate of an isocyanate derivative, and a polymer of an isocyanate derivative.

[0049] When the silicon compound represented by the general formula (2) is a polymer, it is preferably a trimer. 4 Si(OR 3 )3)3(R in the formula 4 (CH2) n , n is 1 or more), which is a condensation product of 3-isocyanatoalkylalkoxysilane.

[0050] The 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate is more preferably 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate, and even more preferably 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate.

[0051] The hydrolyzate can be obtained by a known method, such as a method in which an acid, an alkali, or the like is added to the silicon compound represented by the general formula (2) to carry out hydrolysis.

[0052] Although this 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate loses chemical reactivity in the isocyanurate moiety, it is known to exhibit similar properties to reactive isocyanurates due to the polarity of the isocyanurate moiety. Generally, it is added to adhesives, etc., in the same way as 3-isocyanate alkylalkoxysilane, and is known as an adhesion improver. Therefore, 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate is used as a Si(OR1 By adding 4) to the hydroxyl group-containing polymer compound, swelling of the gas barrier coating layer 4C due to water can be prevented due to hydrogen bonding, and water resistance can be improved.

[0053] In addition, 3-isocyanate alkylalkoxysilane is highly reactive and has low liquid stability, whereas the nurate moiety is not water-soluble due to its polarity, but is easily dispersed in aqueous liquids, allowing the liquid viscosity to be kept stable, and its water resistance is equivalent to that of 3-isocyanate alkylalkoxysilane. Furthermore, the nurate moiety is not only water-resistant, but also has a high water resistance due to its polarity. 1 )4 and water-soluble polymers with hydroxyl groups are less likely to form pores in the barrier.

[0054] In addition, the organic functional group R 2 As the organic functional group, a 3-glycidoxypropyl group or a 2-(3,4-epoxycyclohexyl) group can be preferably used. These organic functional groups can be converted by hydrolysis to Si(OR) groups of the general formula (1). 1 ) 4 and form hydrogen bonds with the hydroxyl group-containing polymer compound, making it difficult for holes to form in the barrier, and improving water resistance without impairing gas barrier properties.

[0055] In the above embodiment, the metal element of the metal alkoxide is silicon, but the metal of the metal alkoxide is not limited to silicon. The metal of the metal alkoxide may be, for example, aluminum.

[0056] Furthermore, known additives such as an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity adjuster, and a colorant may be added to the gas barrier coating layer 4C within a range that does not impair the barrier properties. For example, the isocyanate compound added to the coating agent may be one having two or more isocyanate groups (NCO groups) in its molecule. Examples of the isocyanate compound include monomers such as tolylene diisocyanate (hereinafter referred to as TDI), triphenylmethane triisocyanate (hereinafter referred to as TTI), and tetramethylxylene diisocyanate (hereinafter referred to as TMXDI), as well as polymers and derivatives thereof.

[0057] The thickness of the gas barrier coating layer 4C varies depending on the type of coating agent, but may be, for example, in the range of about 0.01 μm to 100 μm after drying. If the thickness is 50 μm or more, cracks are likely to occur in the film, so the thickness of the coating after drying is more preferably 0.01 μm to 50 μm.

[0058] Examples of methods that can be used to apply the gas barrier coating agent include well-known application methods such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, and spray coating, and well-known printing methods such as offset printing, gravure printing, and silk screen printing.

[0059] The gas barrier coating layer 4C is laminated on the gas barrier vapor deposition layer 4B to fill and reinforce defects or micropores such as pinholes, cracks, and grain boundaries that occur in the gas barrier vapor deposition layer 4B, thereby forming a dense structure, which improves the gas barrier properties and serves as a protective layer for the gas barrier vapor deposition layer 4B. The gas barrier coating layer 4C also has excellent adhesion to the adhesive layer 4D described below.

[0060] The adhesive layer 4D is formed by applying an aqueous medium coating liquid containing an acid-modified polyolefin resin and a silane coupling agent to the gas barrier coating layer 4C, followed by heating and drying, and bonds the gas barrier coating layer 4C to the polyolefin sealant layer 4E (described later). Here, the aqueous medium refers to water or a mixture of water and an organic solvent.

[0061] The acid-modified polyolefin resin used in the adhesive layer 4D is composed mainly of an olefin component and is acid-modified with an unsaturated carboxylic acid component. Examples of acid-modified polyolefin resins include ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid-maleic anhydride copolymers, ethylene-acrylic acid ester-maleic anhydride copolymers, acid anhydride-modified polyethylene, acid anhydride-modified polypropylene, acid anhydride-modified ethylene-propylene resins, acid anhydride-modified ethylene-butene resins, acid anhydride-modified propylene-butene resins, acid anhydride-modified ethylene-propylene-butene resins, and these acid-modified resins further acrylic-modified with acrylic acid esters, etc. Furthermore, the acid-modified polyolefin resins may be chlorinated in a range of 5% by mass to 40% by mass.

[0062] The type of silane coupling agent contained in the adhesive layer 4D is not particularly limited.For example, suitable silane coupling agents for the adhesive layer 4D include epoxy-based silane coupling agents, vinyl-based silane coupling agents, styryl-based silane coupling agents, methacrylic-based silane coupling agents, acrylic-based silane coupling agents, amino-based silane coupling agents, isocyanurate-based silane coupling agents, ureido-based silane coupling agents, mercapto-based silane coupling agents, isocyanate-based silane coupling agents, and acid anhydride-based silane coupling agents.As the silane coupling agent, it is more preferable to use an epoxy-based silane coupling agent.

[0063] The content of the silane coupling agent in the adhesive layer 4D may be 0.2 parts by mass or more and 2.0 parts by mass or less per 100 parts by mass of the acid-modified polyolefin resin, more preferably 0.2 parts by mass or more and 1.5 parts by mass or less, and particularly preferably 0.5 parts by mass or more and 1.0 parts by mass or less. If the content of the silane coupling agent is less than 0.2 parts by mass, the adhesion to the gas barrier coating layer 4C and the olefin-based sealant layer may be poor, whereas if the content of the silane coupling agent is more than 2 parts by mass, the liquid stability of the coating liquid may be poor, making it difficult to apply the coating liquid uniformly to the object to be coated.

[0064] Examples of compounds that can be used as the silane coupling agent include 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. Among these, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane are more preferably used as the silane coupling agent, since they can form an adhesive layer 4D that has excellent adhesion to the gas barrier coating layer 4C and the olefin-based sealant layer.

[0065] The thickness of the adhesive layer 4D (amount of coating after drying) is not particularly limited as long as adhesion is obtained. However, from the viewpoint of processability, it is preferable that the thickness be 0.1 g / m 2 More than 2.0g / m 2 In particular, when laminating by extrusion lamination, it is preferable that the density is 0.3 g / m or less from the viewpoint of resistance to contents. 2 More than 1.0g / m 2 It is more preferable that:

[0066] Examples of methods for applying the adhesive layer 4D include well-known application methods such as dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, and spray coating, as well as well-known printing methods such as offset printing, gravure printing, and silk screen printing.

[0067] The polyolefin sealant layer 4E is a layer portion for heat-sealing the laminated films 4. The polyolefin sealant layer 4E is formed on the outermost layer of the laminated film 4. Examples of resins constituting the polyolefin sealant layer 4E include polyethylene resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HMPE), and ethylene-α-olefin copolymers; polypropylene resins such as homopolypropylene resin, propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer; and ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate, ethylene-ethyl acrylate, and ethylene-methacrylic acid copolymer. Examples of resins that can be used include copolymers with esters of ethylene-α,β-unsaturated carboxylic acid copolymers such as methyl acrylate and ethylene-ethyl methacrylate; ion-crosslinked products of ethylene-α,β-unsaturated carboxylic acid copolymers in which the carboxylic acid moieties are crosslinked with sodium ions or zinc ions; modified polyolefin resins obtained by acid-modifying olefin resins such as acid anhydride-modified polyolefins, typified by ethylene-maleic anhydride graft polymers and terpolymers such as ethylene-ethyl acrylate-maleic anhydride, by graft polymerization; epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers; and resins selected from ethylene-vinyl acetate copolymers, either alone or in blends of two or more thereof. The thickness of the polyolefin sealant layer 4E may be determined appropriately depending on, for example, the seal width, required strength, contents, etc. of the heat-sealed portion 1c of the packaging bag 1. For example, the thickness of the polyolefin sealant layer 4E may be 3 μm or more and 200 μm or less.

[0068] Examples of methods for forming the polyolefin sealant layer 4E include a dry lamination method in which a film made of the above-mentioned resin is bonded using a two-component curing urethane adhesive, a non-solvent dry lamination method in which a solvent-free adhesive is used to bond the film, and an extrusion lamination method in which the above-mentioned resin is heated and melted, extruded into a curtain shape, and bonded together. As a method for forming the polyolefin sealant layer 4E, the back lamination method, in which the above resin is melt-extruded into a single layer or co-melt-extrusion of two or more types by extrusion lamination, or the sand lamination method, in which the resin is melt-extruded onto the inside of the polyolefin sealant film, are particularly preferred, as they can be thermocompressed to the adhesive layer 4D at high temperatures, thereby improving adhesion.

[0069] When the polyolefin sealant layer 4E is melt-extruded onto the adhesive layer 4D surface by the extrusion lamination method, the resin temperature below the T-die is preferably 250°C to 330°C. If the temperature is below 250°C, the extruded polyolefin resin is insufficiently oxidized, resulting in a decrease in adhesive strength with the adhesive layer 4D. If the temperature is above 330°C, the cohesive force of the extruded resin decreases, resulting in a decrease in adhesive strength with the adhesive layer 4D. Furthermore, the portions where the resin extruded from the T-die and the adhesive layer 4D come into contact with each other and their vicinity may be subjected to ozone treatment by flowing ozone therethrough, or surface activation treatment such as corona treatment may be performed before bonding.

[0070] The adhesive layer 4D may be formed by a process in which it is applied to the gas barrier coating layer 4C in advance and dried, and then in a separate process, the polyolefin sealant layer 4E is melt-extruded and bonded by an extrusion lamination method or the like. In this way, the process of forming the adhesive layer 4D and the process of melt-extruding and bonding the polyolefin sealant layer 4E may be performed by separate methods. Alternatively, the adhesive layer 4D may be applied onto the gas barrier coating layer 4C, dried, and then the polyolefin sealant layer 4E may be melt-extruded and bonded in the same process using an extrusion lamination method or the like. If necessary, after forming the laminated film 4, the adhesive strength may be further strengthened by applying heat and pressure by a thermal lamination method.

[0071] The substrate 4A may have a buffer layer made of, for example, oriented nylon, oriented polyester, oriented polypropylene, etc., provided on the surface opposite the gas barrier vapor deposition layer. The provision of such a buffer layer improves the pinhole resistance, impact resistance, heat resistance, and other properties of the laminate film 4.

[0072] The laminated film 4 is formed by laminating the above-described substrate 4A, gas barrier vapor deposition layer 4B, gas barrier coating layer 4C, adhesive layer 4D, and polyolefin sealant layer 4E in this order. However, if other layer portions are provided as necessary, they are laminated in this order with the other layer portions sandwiched between them. The formation order and formation units of each layer portion are not particularly limited. To manufacture the packaging bag 1, first, the laminate film 4 is cut to the outlines of the first laminate film 1a and the second laminate film 1b, respectively. The first laminate film 1a and the second laminate film 1b are then laminated together with their polyolefin sealant layers 4E facing each other. The laminate of the first laminate film 1a and the second laminate film 1b is heat-sealed on three sides by a heat-sealing device. This produces a packaging bag 1 that is open on one side. If a fragile portion such as an opening assist line is provided on the spout 1d of the packaging bag 1, the fragile portion is formed at some point before the packaging bag 1 is formed. For example, laser processing or the like may be used to process the fragile portion.

[0073] Once the packaging bag 1 is manufactured, the highly permeable contents 2 are filled in through the opening. After this, the opening of the packaging bag 1 is heat-sealed by a heat-sealing device. In this way, a heat-sealed portion 1c is formed around the entire outer periphery of the packaging bag 1. As a result, the packaging bag 1 is sealed, and a package 3 is manufactured.

[0074] Next, the functions of the laminated film 4 and the packaging bag 1 of this embodiment will be described. As described above, the laminated film 4 includes a gas barrier vapor deposition layer 4B, a gas barrier coating layer 4C, and an adhesive layer 4D, each of which has gas barrier properties, between the substrate 4A and the polyolefin sealant layer 4E. The gas barrier properties of the gas barrier vapor-deposited layer 4B are obtained by forming a dense layer structure of the inorganic compounds contained in the gas barrier vapor-deposited layer 4B. Such inorganic compound layers are hard but brittle, and therefore are prone to cracking when external force is applied, such as when the laminated film 4 is bent, which can cause a decrease in gas barrier properties. In this embodiment, the gas barrier vapor deposition layer 4B is further coated with a gas barrier coating layer 4C.

[0075] In the gas barrier coating layer 4C, for example, a silicon compound of general formula (1) is hydrolyzed, forming strong hydrogen bonds between the hydroxyl groups of the hydrolyzate of the silicon compound and the hydroxyl groups of the hydroxyl-containing polymer compound. Therefore, in the gas barrier coating layer 4C, a flexible hydroxyl-containing polymer compound is dispersed in a dense silicon compound network. The hydroxyl-containing polymer compound bonds to sites derived from the arrangement of functional groups in the silicon compound of general formula (1), and is therefore dispersed evenly over a wide area. As a result, the aforementioned pores through which gas can easily pass are less likely to form inside the film structure. In this way, the gas barrier vapor deposition layer 4B is coated with the gas barrier coating layer 4C, which has both gas barrier properties and flexibility, and this synergistic effect further improves the gas barrier properties of the laminated film 4. In this way, the laminated film 4 suppresses the permeation of highly permeable materials.

[0076] Furthermore, in the gas barrier coating layer 4C, the hydroxyl groups formed by hydrolysis of the silicon compound of general formula (2) form strong hydrogen bonds with the hydroxyl groups of the hydrolyzate of the silicon compound of general formula (1) and with the hydroxyl groups of the hydroxyl-containing polymer compound. Meanwhile, the hydrophobic organic functional groups of general formula (2) form a network, preventing swelling even when water is added to the hydrogen bonds of the hydroxyl-containing polymer compound. This significantly improves the water resistance of the film structure.

[0077] Furthermore, in this embodiment, at the adhesive joint between the gas barrier coating layer 4C and the adhesive layer 4D, the highly polar silanol groups generated by hydrolysis of the silicon compounds represented by general formulas (1) and (2) in the gas barrier coating layer 4C interact with the highly polar epoxy groups of the epoxy-based silane coupling agent in the adhesive layer 4D to form a strong bond, allowing the gas barrier coating layer 4C and the adhesive layer 4D to maintain their adhesive strength even when highly permeable substances contained in the highly permeable contents reach them. Furthermore, the highly polar hydroxyl groups of the hydroxyl group-containing polymer compound in the gas barrier coating layer 4C interact with the highly polar epoxy groups of the epoxy-based silane coupling agent in the adhesive layer 4D to form a strong bond, allowing the gas barrier coating layer 4C and the adhesive layer 4D to maintain their adhesive strength even when highly permeable substances from the highly permeable contents reach them.

[0078] Furthermore, since the polyolefin resin component of the acid-modified polyolefin resin in the adhesive layer 4D and the polyolefin resin in the polyolefin-based sealant layer 4E are of the same resin system, strong adhesive strength is created, and the adhesive layer 4D and the polyolefin-based sealant layer 4E can maintain their adhesive strength even if highly permeable substances from the highly permeable contents reach them.

[0079] As described above, according to the packaging material and package of this embodiment, even if the contents to be packaged are highly permeable contents, the decrease in laminate strength due to the influence of the highly permeable contents is suppressed. [Example]

[0080] Examples 1 to 8 of the laminated film 4 and packaging body 3 of the above embodiment will be described below, along with Comparative Examples 1 to 5. Table 1 below shows the layer structures of the packaging materials, the types of contents, and the evaluation results for Examples 1 to 8 and Comparative Examples 1 to 5. However, in Table 1, the reference numerals for each layer are omitted.

[0081] [Table 1]

[0082] The compositions of compositions A to E in [Table 1] are shown in [Table 2] below.

[0083] [Table 2]

[0084] [Example 1] As shown in Table 1, a 12 μm thick polyethylene terephthalate film (referred to as "PET" in Table 1) with no surface treatment was used as the substrate 4A of the packaging material of Example 1. Aluminum oxide was used for the gas barrier vapor-deposited layer 4B. The aluminum oxide was formed on the substrate 4A by vacuum deposition to a thickness of 15 nm. The ratio B / A of aluminum (B) to oxygen (A) in the gas barrier vapor-deposited layer 4B was measured by XPS (X-ray photoelectron spectroscopy) and found to be 1 / 1.8. Composition A was used as the material for the gas barrier coating layer 4C. Composition A contained tetraethoxysilane (Si(OC2H5)4, hereinafter referred to as TEOS), a metal alkoxide, or pre-hydrolyzed TEOS, a polymer of these, and PVA, a polymer compound having a hydroxy group.

[0085] A coating liquid described below was applied to the upper surface of the gas barrier vapor-deposited layer 4B formed of aluminum oxide using a bar coater. The coating solution used was a mixed solution (gas barrier coating solution) of coating solutions (a) and (b) prepared by the following method: The mixing ratio of coating solutions (a) and (b) was a:b=70:30, where a and b represent the masses of the solid contents of each solution. Solution (a) for coating liquid was obtained by adding 17.9 g of TEOS, 10.0 g of methanol, and 72.1 g of hydrochloric acid (0.1 N), stirring for 30 minutes, and hydrolyzing the mixture. The solid content of the hydrolysis solution was 5% (compared to SiO2 by mass). As the solution (b) for the coating liquid, an aqueous solution of 5% (mass ratio) polyvinyl alcohol and water / methanol=95 / 5 (mass ratio) was obtained. After coating the mixed solution, the coating film was dried in a dryer at 120° C. for 1 minute, thereby forming a gas barrier coating layer 4C with a thickness of about 0.3 μm.

[0086] Composition A was used as the material for adhesive layer 4D. As shown in Table 2, composition A was obtained as an aqueous dispersion in which 1 part by mass of 3-glycidoxypropyltrimethoxysilane, an epoxy-based silane coupling agent, was added to 100 parts by mass of acid anhydride-modified polyethylene resin. The adhesive layer 4D was applied onto the gas barrier coating layer 4C by bar coating, and the coating film was dried in a dryer at 120°C for 1 minute to give a coating amount of 0.5 g / m 2 The film was formed so that A low-density polyethylene (LDPE) with a thickness of 20 μm was used as the polyolefin sealant layer 4E (referred to as the "sealant layer" in Table 1). The polyolefin sealant layer 4E was laminated onto the adhesive layer 4D by extrusion lamination at a temperature of 290°C. In this manner, laminated film 4 of Example 1 was produced.

[0087] The laminate film 4 of Example 1 was cut into the shapes of the first laminate film 1a and the second laminate film 1b, and then heat-sealed on three sides of the periphery to form a packaging bag 1. The packaging bag 1 was filled with highly permeable contents α (referred to as "contents α" in Table 1) containing a highly permeable material through the opening. As the highly penetrating ingredient α, l-menthol was used. After the highly permeable contents α were filled, the opening of the packaging bag 1 was heat-sealed, thereby producing the packaging body 3 of Example 1 having a bag shape sealed on all four sides.

[0088] [Examples 2 to 8] (packaging material) As shown in Table 1, the laminated film 4 of Example 2 was configured in the same manner as the laminated film 4 of Example 1, except that composition B was used instead of composition A as the adhesive layer 4D. As shown in Table 2, composition B was composed in the same manner as composition A, except that the amount of 3-glycidoxypropyltrimethoxysilane in composition A was changed to 0.5 parts by mass. As shown in Table 1, the laminated film 4 of Example 3 was configured in the same manner as the laminated film 4 of Example 1, except that composition C was used instead of composition A as the adhesive layer 4D. As shown in Table 2, composition C was composed in the same manner as composition A, except that 3-glycidoxypropylmethyldimethoxysilane was used instead of 3-glycidoxypropyltrimethoxysilane.

[0089] As shown in Table 1, the laminate film 4 of Example 4 was constructed in the same manner as the laminate film 4 of Example 1, except that the material of the gas barrier vapor-deposited layer 4B was changed from aluminum oxide to silicon oxide. The abundance ratio B / A of oxygen (B) to silicon (A) in the silicon oxide was 1.5.

[0090] The laminated film 4 of Example 5 was constructed in the same manner as the laminated film 4 of Example 1, except that a coating layer was formed on the surface of the substrate 4A, and then the gas barrier vapor deposition layer 4B was formed to improve the adhesion of the gas barrier vapor deposition layer 4B. The material used for the coating layer was a solution prepared by adding acrylic polyol and triisocyanate so that the number of NCO groups was equal to the number of OH groups in the acrylic polyol, diluting with ethyl acetate to a total solid content of 5% by mass, and adding and mixing β-(3,4-epoxycyclohexyl)trimethoxysilane at 5% by mass relative to the total solid content. The mixed solution described above was applied to the gas barrier vapor deposition layer 4B using a bar coater, and dried in a dryer at 120° C. for 1 minute to obtain a coating layer with a thickness of about 0.3 μm.

[0091] The laminated film 4 of Example 6 was constructed in the same manner as the laminated film 4 of Example 1, except that the surface of the substrate 4A was subjected to oxygen plasma treatment and then the gas barrier vapor deposition layer 4B was formed to improve the adhesion of the gas barrier vapor deposition layer 4B.

[0092] The laminated film 4 of Example 7 was configured in the same manner as the laminated film 4 of Example 1, except that composition b was used as the material for the gas barrier coating layer 4C. Composition b was formed using a gas barrier coating solution in which the coating solution solutions (a) and (b) described in Example 1 were added with the coating solution solution (c) described below. The coating solution (c) was prepared by dissolving 1,3,5-tris(3-methoxysilylpropyl) isocyanurate in a water / IPA=1 / 1 solution at a solid content of 5% (weight ratio R 2 The solution was diluted and adjusted to Si(OH)3 equivalent. The mixing ratio of the coating solutions (a), (b), and (c) was A:B:C = 100:20:10, where A is the solid content (converted value) of SiO2 in TEOS, B is the solid content of PVA, and C is the R of 1,3,5-tris(3-methoxysilylpropyl) isocyanurate. 2 The solid content (equivalent value) is Si(OH)3. Composition b was formed into a film using this coating liquid in the same manner as the gas barrier coating layer of composition a.

[0093] The laminated film 4 of Example 8 was constructed in the same manner as the laminated film 4 of Example 7, except that a coating layer was formed on the surface of the substrate 4A in the same manner as in Example 5, and then the gas barrier vapor deposition layer 4B was formed in order to improve the adhesion of the gas barrier vapor deposition layer 4B.

[0094] (packaging) The packages 3 of Examples 2-8 were produced in the same manner as the package 3 of Example 1, except that the packaging bag 1 was produced using the laminated film 4 of Examples 2-8.

[0095] [Comparative Examples 1 to 8] (packaging material) The laminated films of Comparative Examples 1 and 2 were constructed in the same manner as the laminated film 4 of Example 1, except that compositions D and E were used in place of composition A in the adhesive layer 4D. The coating amount of the adhesive layer in each of Comparative Examples 1 and 2 after drying was 0.5 g / m 2 It was said that. As shown in Table 2, composition D was a two-component curing polyester polyurethane resin. The solid content of composition D was 30% by mass, and the coating amount of composition D after drying was 0.5 g / m 2 After applying the coating using a bar coater so that the coating became as shown in the figure, the coating was dried for 1 minute at 120° C. This formed the adhesive layer of Comparative Example 1. Composition E was composed of an acid-modified polyethylene resin containing no silane coupling agent. The acid-modified polyethylene resin used was the same material as the acid-modified polyethylene resin of Composition A.

[0096] As shown in Table 1, the laminated films of Comparative Examples 3 and 4 were constructed in the same manner as Examples 1 and 4, respectively, except that they did not have a gas barrier coating layer. The laminated film of Comparative Example 5 was constructed in the same manner as the laminated film 4 of Example 1, except that composition c was used as the material for the gas barrier coating layer. Composition c was a polyester-based aqueous emulsion used as an overcoat. The solid content of composition c was 30 mass %. Composition c was applied using a bar coater so that the film thickness after drying would be 0.3 μm, and then dried at 120° C. for 1 minute. This formed a non-gas barrier coating layer of Comparative Example 5. The laminated film of Comparative Example 6 had a coating amount of 2.5 g / m after drying of the adhesive layer. 2 The laminated film was constructed in the same manner as the laminated film 4 of Example 1, except for the above. The laminated film of Comparative Example 7 was constructed in the same manner as the laminated film 4 of Example 1, except that the temperature during extrusion lamination was 240°C. The laminated film of Comparative Example 8 was constructed in the same manner as the laminated film 4 of Example 1, except that the temperature during extrusion lamination was 350°C.

[0097] (packaging) The packages of Comparative Examples 1 to 8 were produced in the same manner as package 3 of Example 1, except that packaging bags similar to package 1 were produced using the laminated films of Comparative Examples 1 to 8.

[0098] [evaluation] To evaluate each example and comparative example, each packaging bag was stored at 40°C and 90% humidity for one month and then opened. The presence or absence of deterioration of the laminated film of the opened packaging bag, which was thought to have occurred due to the influence of the contents, was examined. Specifically, the lamination strength and water vapor barrier property of the laminated film were examined. The evaluation was done on a three-point scale: good (marked "○" in [Table 1]), bad (marked "△" in [Table 1]), and very bad (marked "×" in [Table 1]). The laminate strength was measured based on JIS Z 1707. The details of each stage are as follows: "Good": 5N / 15mm or more "Poor": Range between "Good" and "Very Poor" "Very bad": 2N / 15mm or less The water vapor barrier properties were measured in accordance with JIS Z7129. The details of each stage are as follows: "Good": 0.5g / m 2 / day or less "Poor": Range between "Good" and "Very Poor" "Very poor": 1.0 g / m 2 / day or more

[0099] [Evaluation results] As shown in Table 1, Examples 1 to 8 were evaluated as "good" in both laminate strength and water vapor barrier property. In contrast, in Comparative Examples 3 and 4, elongation of the LDPE extrusion lamination resin was observed, which is thought to be due to the laminate strength, and both the laminate strength and the water vapor barrier property were evaluated as "poor." In Comparative Examples 1, 2, 5, 6, and 7, delamination occurred between layers, and the laminate strength was evaluated as "very poor." In Comparative Example 8, the resin, which had become more fluid due to high-temperature extrusion, destroyed the vapor-deposited gas barrier layer, and the water vapor barrier property was evaluated as "very poor." From the above results, it can be seen that in Examples 1 to 8, even when the contents to be packaged were highly permeable, the decrease in laminate strength due to the influence of the highly permeable contents was suppressed and the water vapor barrier properties were also maintained.

[0100] A second embodiment of the present invention will be described with reference to Figures 3 to 5. In the following description, components common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0101] 3 is a schematic cross-sectional view of a packaging material 50 according to this embodiment. The packaging material 50 has a configuration in which the laminated film 4 of the first embodiment and a paper sheet 10 are joined together.

[0102] The paper constituting the sheet 10 has a basis weight of 200 to 500 g / m depending on the size of the paper container to be formed. 2 , density 0.6~1.1g / cm 3 The basis weight can be selected from those within the range of 200 g / m 2 If the thickness is less than 500g / m, the container may not have sufficient strength or stiffness. 2 If the thickness exceeds this range, the processability when molding into a container will be poor, and it is not economically preferable.

[0103] A surface resin layer 12 is formed on one side of the sheet. The surface resin layer 12 constitutes the outer surface of the paper container for liquids, which will be described later, and is made of a polyolefin resin. The thickness of the surface resin layer 12 can be, for example, about 10 to 50 μm. The surface resin layer 12 can be formed by extrusion lamination.

[0104] The polyolefin sealant layer 4E of the laminated film 4 shown in Fig. 3 includes a polyolefin resin layer 41 and a polyolefin resin sealant film 42, and is formed by the above-mentioned extrusion lamination method such as sand lamination or back lamination. The thickness of the polyolefin sealant layer 4E can be, for example, about 40 to 100 µm. This is just one example, and the configuration of the polyolefin sealant layer 4E may be any of the aspects described in the first embodiment.

[0105] The laminated film 4 is disposed with the substrate 4A side facing the sheet 10. The laminated film 4 and the sheet 10 are bonded together by a bonding resin layer 11 on the surface opposite to the surface resin layer 12. The bonding resin layer 11 can be formed of a polyolefin resin. The thickness of the bonding resin layer 11 can be, for example, about 10 to 50 μm. The bonding resin layer 11 can be formed by an extrusion lamination method.

[0106] Specific examples of resins forming the surface resin layer 12, the bonding resin layer 11, and the polyolefin resin layer 41 include polyethylene resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HMPE), and ethylene-α-olefin copolymers; polypropylene resins such as homopolypropylene resin, propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer; and ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-α-olefin copolymer, and ethylene-α-olefin copolymer. Examples of resins that can be used include copolymers of esters of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-methyl methacrylate and ethylene-ethyl methacrylate; ion-crosslinked products of ethylene-α,β-unsaturated carboxylic acid copolymers in which the carboxylic acid moieties are crosslinked with sodium ions or zinc ions; modified polyolefin resins obtained by acid-modifying olefin resins such as acid anhydride-modified polyolefins, typified by ethylene-maleic anhydride graft polymers and terpolymers such as ethylene-ethyl acrylate-maleic anhydride, through graft polymerization; epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers; and resins selected from ethylene-vinyl acetate copolymers, either alone or in blends of two or more thereof. The above resins may be melt-extruded in a single layer or in a co-melt extrusion of two or more kinds. The resin temperature below the T-die during melt extrusion by the extrusion lamination method is preferably 250°C to 330°C. If the temperature is below 250°C, the extruded polyolefin resin will not be sufficiently oxidized, resulting in a decrease in interlayer adhesive strength. If the temperature is above 330°C, the cohesive strength of the extruded resin will decrease, resulting in a decrease in interlayer adhesive strength. Furthermore, the resin extruded from the T-die and its vicinity can be subjected to ozone treatment by flowing ozone therethrough, or surface activation treatment such as corona treatment can be performed before bonding. Since the bonding resin layer 11 contacts the base material 4A, among the above, preferred are ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA), copolymers with esters of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, and ethylene-ethyl methacrylate, ion-crosslinked products of ethylene-α,β-unsaturated carboxylic acid copolymers in which the carboxylic acid moieties are crosslinked with sodium ions or zinc ions, modified polyolefin resins obtained by acid-modifying olefin resins such as acid anhydride-modified polyolefins typified by graft polymerization or the like by terpolymerization, epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymer, and ethylene-vinyl acetate copolymer, a single layer or a blend of two or more types of resins selected from the group consisting of a single resin and a co-melt extrusion of two or more layers.

[0107] The packaging material 50 can be produced by preparing a sheet 10 having a surface resin layer 12 formed thereon and a laminated film 4, and bonding the sheet 10 and the laminated film 4 together while forming a bonding resin layer 11 using an extrusion lamination method. If necessary, after joining the sheet 10 and the laminated film 4, the adhesive strength may be further strengthened by applying heat and pressure by a thermal lamination method.

[0108] Another example of a packaging material is shown in Figure 4. In the packaging material 50A shown in the figure, the laminate film 4 and the sheet 10 are joined by the polyolefin sealant layer 4E of the laminate film 4. On the surface of the substrate 4A that does not face the sheet 10, a container sealant layer 13 having a polyolefin resin layer 13A and a polyolefin resin sealant film 13B is formed by the extrusion lamination sand lamination method. The materials of the polyolefin resin layer 13A and the polyolefin resin sealant film 13B can be the same as those of the polyolefin resin layer 41 and the polyolefin resin sealant film 42 in the packaging material 50. In this case, since the polyolefin resin layer 41 is in contact with the base material 4A, similar to the bonding resin layer 11, it is preferable to use a single layer or two or more layers of co-melt extrusion of a resin selected from the group consisting of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA), copolymers of esters of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, and ethylene-ethyl methacrylate, ion-crosslinked products of ethylene-α,β-unsaturated carboxylic acid copolymers in which the carboxylic acid moieties are crosslinked with sodium ions or zinc ions, modified polyolefin resins obtained by acid-modifying olefin resins such as acid anhydride-modified polyolefins typified by graft polymerization, epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymer, and ethylene-vinyl acetate copolymer, or a single layer or a blend of two or more types of resins selected from the group consisting of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, and ethylene-ethyl methacrylate.

[0109] When producing packaging material 50A, a portion of laminate film 4 excluding polyolefin sealant layer 4E is prepared. Container sealant layer 13 is formed on this by extrusion lamination sand lamination, and then sheet 10 on which surface resin layer 12 is formed is bonded to laminate film 4 while polyolefin sealant layer 4E is formed by extrusion lamination sand lamination, thereby producing packaging material 50A. In this case, the adhesive layer 4D may be formed and dried in advance, or may be formed in the same step as forming the polyolefin-based sealant layer 4E by extrusion lamination. If necessary, after joining the sheet 10 and the laminated film 4, the adhesive strength may be further strengthened by applying heat and pressure by a thermal lamination method.

[0110] The packaging material 50 or 50A can be made into a blank for a paper container for liquid by forming fold lines by pressing or the like and punching it into a predetermined shape. The blank is folded along the fold lines, assembled, and the necessary parts are heat-sealed to produce a paper container for liquid made from the packaging material of this embodiment. Because the paper container for liquids according to this embodiment is manufactured using the laminate film 4, the laminate strength between the gas barrier vapor deposition layer 4B and the gas barrier coating layer 4C and the polyolefin sealant layer 4E is excellent. Therefore, even when filled with volatile substances or various highly permeable contents containing volatile substances, such as perm solution, detergent, concentrated detergent, shampoo, conditioner, bath additives, and air fresheners, the laminate strength between the gas barrier vapor deposition layer 4B and the gas barrier coating layer 4C and the polyolefin sealant layer 4E is not reduced, making the container suitable for use as a paper container for liquids containing heavy contents or for long-term storage. Furthermore, the container has excellent barrier properties against water vapor and other elements.

[0111] Figure 5 shows a Gabeltop-type paper container 100 for liquids as an example of a paper container for liquids using the packaging material 50. When manufacturing the paper container 100 for liquids, the blank described above is folded to create a cylindrical body. Next, a bottom is formed to create a bottomed container. The contents are filled into this bottomed container, and the top opening is folded and sealed to form a top surface. This completes the paper container 100 for liquids (package) filled and sealed with the contents.

[0112] The shape of the paper container for liquid is not limited to the Gabeltop type described above, but may be a flat-top type in which the top is folded flat, or any other suitable shape. In this embodiment, when the liquid paper container is produced, a part of the surface resin layer 12 is joined by heat fusion to the polyolefin sealant layer 4E or the container sealant layer 13. Therefore, it is preferable that the material of the surface resin layer 12 is one that can be heat fused to the corresponding polyolefin sealant layer 4E or container sealant layer 13. The surface resin layer 12 and the polyolefin-based sealant layer 4E may be blended with a low-crystalline rubber component.

[0113] In this embodiment, the container sealant layer 13 and the polyolefin sealant layer 4E (or the innermost layer if these layers are composed of multiple layers) that form the inner surface of the paper container for liquids are preferably formed from polyolefins polymerized using a single-site catalyst such as a metallocene catalyst (metallocene polyolefins). It is known that the structural characteristics of ethylene polymers and propylene polymers, such as molecular weight, molecular weight distribution, and branched structure, can be controlled by selecting the catalyst, and those skilled in the art can also distinguish between types of polymers based on the type of catalyst. Polyolefins using a single-site catalyst have a uniform molecular weight distribution, which allows for stable seal strength.

[0114] The second embodiment will be further described below using examples and comparative examples. The layer structures and evaluation results of the laminated films in the packaging materials of Examples 9 and 10 and Comparative Examples 9 and 10 are shown in Table 3 below.

[0115] [Table 3]

[0116] Example 9 A laminated film similar to that of Example 1 was prepared, except that an ethylene-α-olefin copolymer polymerized using a metallocene catalyst was used as the sealant layer. Sheet 10, basis weight 400 g / m 2 A surface resin layer 12 made of LDPE and having a thickness of 20 μm was formed on one surface of the sheet 10 by extrusion lamination. The substrate of the laminated film was placed opposite the surface of the sheet 10 on which the surface resin layer 12 was not provided, and the laminated film and the sheet were bonded together by extrusion lamination (extrusion temperature 290°C) using an ethylene-unsaturated carboxylic acid copolymer. This produced the packaging material of Example 9 having a 20 μm-thick bonding resin layer 11.

[0117] Example 10 A laminated film similar to that of Example 8 was prepared, except that an ethylene-α-olefin copolymer polymerized using a metallocene catalyst was used as the sealant layer. This laminated film was attached to sheet 10 in the same manner as in Example 9, to produce the packaging material of Example 10.

[0118] (Comparative Example 9) A laminated film similar to that of Comparative Example 1 was prepared, except that an ethylene-α-olefin copolymer polymerized using a metallocene catalyst was used as the sealant layer. This laminated film was attached to sheet 10 in the same manner as in Example 9, to produce the packaging material of Comparative Example 9. (Comparative Example 10) A laminated film similar to that of Comparative Example 2 was prepared, except that an ethylene-α-olefin copolymer polymerized using a metallocene catalyst was used as the sealant layer. This laminated film was attached to sheet 10 in the same manner as in Example 9, to produce the packaging material of Comparative Example 10.

[0119] The packaging materials of each Example and Comparative Example were punched into a predetermined shape to prepare blanks, and the Goebel-top type paper containers for liquids of each Example were fabricated. The contents α were filled into these blanks and sealed to prepare the packages of each Example. The packaging bags of each example were evaluated for lamination strength and water vapor barrier properties in the same manner as in the examples according to the first embodiment.

[0120] As shown in Table 3, Examples 9 and 10 were evaluated as "good" in both laminate strength and water vapor barrier property. In contrast, in Comparative Examples 9 and 10, delamination occurred between layers, and the laminate strength was evaluated as "very poor." From the above results, it can be seen that in the liquid paper container of the second embodiment, even if the contents to be packaged are highly permeable contents, the decrease in laminate strength due to the influence of the highly permeable contents is suppressed, and the water vapor barrier properties are also maintained.

[0121] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples. Additions, omissions, substitutions, and other modifications to the configuration are possible within the scope of the present invention. Furthermore, the present invention is not limited by the foregoing description, but is limited only by the appended claims. [Industrial Applicability]

[0122] The present invention is applicable to packaging materials and packages. [Explanation of symbols]

[0123] 1 packaging bag 1a First laminated film 1b Second laminated film 1c Heat seal section 1d Spout 2 Highly permeable contents 3 Packaging 4. Laminated film (packaging material) 4A Base material 4B Gas barrier vapor deposition layer 4C Gas barrier coating layer 4D adhesive layer 4E polyolefin sealant layer 10 sheets 50, 50A packaging material 100 liquid cartons

Claims

1. forming a gas barrier vapor-deposited layer made of an inorganic compound on a substrate made of a polymer resin composition; forming a gas barrier coating layer on the gas barrier vapor deposition layer using a composition containing at least one compound selected from a metal alkoxide, a hydrolyzate of a metal alkoxide, and a polymer of a metal alkoxide, and a hydroxy group-containing polymer compound; an aqueous medium coating liquid containing an acid-modified polyolefin resin and a silane coupling agent is applied onto the gas barrier coating layer, and the coating liquid is dried by heating to form an adhesive layer; A polyolefin sealant layer is laminated on the adhesive layer by an extrusion lamination method at an extrusion temperature of 250°C to 330°C, The coating amount of the adhesive layer after drying is 0.1 to 2.0 g / m ２ That is, A method for manufacturing packaging materials.

2. The gas barrier coating layer is A composition formed by using a composition containing at least one compound selected from a metal alkoxide, a hydrolysate of a metal alkoxide, and a polymer of a metal alkoxide, and a hydroxy group-containing polymer compound, and further using at least one compound selected from an isocyanate derivative, a hydrolysate of an isocyanate derivative, and a polymer of an isocyanate derivative. A method for producing the packaging material according to claim 1.

3. The adhesive layer is the silane coupling agent is contained in an amount of 0.2 parts by mass or more and 2.0 parts by mass or less relative to 100 parts by mass of the acid-modified polyolefin resin; A method for producing the packaging material according to claim 1 or 2.

4. The silane coupling agent is It is an epoxy-based silane coupling agent. A method for producing the packaging material according to any one of claims 1 to 3.

5. The epoxy-based silane coupling agent is at least one compound selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyltriethoxysilane; A method for producing the packaging material according to claim 4.

6. The gas barrier vapor deposition layer is containing at least one of silicon oxide and aluminum oxide; A method for producing the packaging material according to any one of claims 1 to 5.

7. The metal alkoxide is At least one compound selected from the group consisting of tetraethoxysilane, tetramethoxysilane, and triisopropoxyaluminum, A method for producing the packaging material according to any one of claims 1 to 6.

8. A packaging bag formed using the packaging material manufactured by the manufacturing method according to any one of claims 1 to 7, The container contains a highly permeable content containing a highly permeable material. A method for manufacturing a package.

9. Further joining of paper sheets, A method for producing the packaging material according to any one of claims 1 to 7.

10. A paper container for liquid formed using a packaging material manufactured by the manufacturing method according to claim 9, The container contains a highly permeable content containing a highly permeable material. A method for manufacturing a package.

11. After the adhesive layer forming step of applying the aqueous medium coating liquid and heating and drying it to form the adhesive layer is performed, the polyolefin sealant layer is laminated in a step separate from the adhesive layer forming step. A method for producing the packaging material according to any one of claims 1 to 7.

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