Barrier laminate, packaging product, and method for manufacturing barrier laminate

Abstract

To provide a barrier laminate excellent in adhesion of a barrier coat layer and an acid modified polyolefin layer.SOLUTION: A barrier laminate includes a paper substrate layer, a barrier layer, and a sealant layer in this order, and further includes an acid modified polyolefin layer between the paper substrate layer and the barrier layer or between the barrier layer and the sealant layer. In a barrier film, the barrier layer includes a base material film, a first inorganic oxide vapor-deposited layer, and a barrier coat layer in this order. The barrier coat layer is a cured film of a hydrolyzed product of metalalkoxide and a water-soluble polymer. When a surface of the barrier coat layer is measured by X-ray photoelectron spectroscopy (XPS), a ratio (M / C) of metal atoms (M) and carbon atoms (C) is 1.35 or less. The barrier coat layer has a thickness of 155 nm or more. The acid modified polyolefin layer abuts on the barrier coat layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a barrier laminate, a packaging product, and a method for manufacturing a barrier laminate.

Background Art

[0002] Packaging products used for packaging foods, daily necessities, pharmaceuticals, etc. are required to have a high gas barrier property in order to suppress the deterioration and degradation of the contents due to oxygen gas. In response to such requirements, barrier films having a gas barrier property have been proposed as films used for packaging products.

[0003] For example, in Patent Document 1, a gas barrier material (barrier film) is proposed, which includes a polymer resin substrate, a gas barrier vapor deposition layer composed of an inorganic compound mainly containing a metal and / or a metal compound provided on one side of the polymer resin substrate, and a coating layer (barrier coat layer) composed of a composite of a hydrolysis product of a metal alkoxide and a water-soluble polymer resin provided on the gas barrier vapor deposition layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When manufacturing a packaging product such as a paper container from a barrier film, first, a barrier laminate is produced by laminating a barrier film, a paper base material layer, and a sealant layer, and then the barrier laminate is formed into a box or a bag for the packaging product. This barrier laminate requires an adhesion such that peeling does not occur between the layers when forming the box or the bag.

[0006] However, since the barrier coat layer provided in the barrier film has poor adhesion to layers such as the paper base material layer and the sealant layer, the barrier laminate may peel between those layers. In order to suppress this, in order to laminate the barrier coat layer and layers such as the paper base material layer and the sealant layer through a resin layer having adhesiveness such as an acid-modified polyolefin layer, but there was room for improvement in the adhesion between these layers.

[0007] Now, the present inventor was producing a barrier laminate using a barrier film provided with various barrier coat layers, and noticed that there is a barrier laminate having excellent adhesion between the barrier coat layer and the acid-modified polyolefin layer. And the present inventor noticed that this good adhesion is due to the composition and thickness of the barrier coat layer.

[0008] The present invention has been made in view of the above findings, and an object thereof is to provide a barrier laminate having excellent adhesion between a barrier coat layer and an acid-modified polyolefin layer. Another object of the present invention is to provide a packaging product provided with the above barrier laminate. Another object of the present invention is to provide a method for producing the above barrier laminate.

Means for Solving the Problems

[0009] The present invention is a barrier laminate comprising a paper base material layer, a barrier layer, and a sealant layer in this order, and having an acid-modified polyolefin layer between either the paper base material layer and the barrier layer or between the barrier layer and the sealant layer, where the barrier layer is a barrier film comprising a base film, a first inorganic oxide vapor deposition layer, and a barrier coat layer in this order, the barrier coat layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer, when the surface of the barrier coat layer is measured by X-ray photoelectron spectroscopy (XPS), the ratio (M / C) of the metal atom (M) to the carbon atom (C) is 1.35 or less, The thickness of the barrier coating layer is 155 nm or more. The acid-modified polyolefin layer is a barrier laminate in contact with the barrier coat layer.

[0010] In the barrier laminate according to the present invention, the hardness of the barrier coating layer may be 1.25 GPa or less.

[0011] In the barrier laminate according to the present invention, the ratio (M / C) may be 0.80 or more and 1.35 or less.

[0012] In the barrier laminate according to the present invention, the plastic deformation rate of the barrier coat layer may be 35% or more.

[0013] In the barrier laminate according to the present invention, the first inorganic oxide vapor deposition layer may include an aluminum oxide vapor deposition film or a silicon oxide vapor deposition film.

[0014] In the barrier laminate according to the present invention, the barrier film further comprises a second inorganic oxide vapor deposition layer, The base film may be located between the first inorganic oxide vapor deposition layer and the second inorganic oxide vapor deposition layer.

[0015] In the barrier laminate according to the present invention, the second inorganic oxide vapor deposition layer may include an aluminum oxide vapor deposition film or a silicon oxide vapor deposition film.

[0016] In the barrier laminate according to the present invention, the acid-modified polyolefin layer is provided between the substrate layer and the barrier layer, and between the barrier layer and the sealant layer, and the olefin-unsaturated carboxylic acid copolymer layer is provided between the other, The acid-modified polyolefin layer is in contact with the barrier coat layer, The olefin-unsaturated carboxylic acid copolymer layer may be in contact with the second inorganic oxide deposition layer.

[0017] The present invention is a packaging product comprising the barrier laminate described above.

[0018] The present invention is a method for manufacturing a barrier laminate, The barrier laminate comprises a paper substrate layer, a barrier layer, and a sealant layer in this order, and an acid-modified polyolefin layer is provided between the paper substrate layer and the barrier layer, and between the barrier layer and the sealant layer, The barrier layer is a barrier film comprising a base film, a first inorganic oxide vapor deposition layer, and a barrier coating layer in this order. The barrier coating layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer. When the surface of the barrier coating layer is measured by X-ray photoelectron spectroscopy (XPS), the ratio of metal atoms (M) to carbon atoms (C) (M / C) is 1.35 or less. The thickness of the barrier coating layer is 155 nm or more. The acid-modified polyolefin layer is in contact with the barrier coat layer, The method for manufacturing a barrier laminate comprises the step of applying a barrier coating liquid containing a gas barrier composition onto the first inorganic oxide vapor deposition layer and heating and drying it at 130°C or higher and less than 200°C to form the barrier coating layer. [Effects of the Invention]

[0019] According to the present invention, a barrier laminate exhibiting excellent adhesion between the barrier coating layer and the acid-modified polyolefin layer can be provided. According to the present invention, a packaging product comprising the above-mentioned barrier laminate can be provided. According to the present invention, a method for manufacturing the above-mentioned barrier laminate can be provided. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic cross-sectional view showing one embodiment of the barrier laminate according to the present invention. [Figure 2] This is a schematic cross-sectional view showing one embodiment of the barrier laminate according to the present invention. [Figure 3] This is a schematic cross-sectional view showing one embodiment of the barrier laminate according to the present invention. [Figure 4] This is a schematic cross-sectional view showing one embodiment of the barrier laminate according to the present invention. [Figure 5] This is a schematic perspective view showing one embodiment of a paper container, which is an example of a packaging product according to the present invention. [Figure 6] This is a schematic front view showing one embodiment of a packaging bag, which is an example of a packaging product according to the present invention. [Figure 7] This is a schematic diagram illustrating a method for measuring adhesion strength. [Figure 8] This is a schematic diagram illustrating a method for measuring adhesion strength. [Figure 9] This figure shows the results of the adhesion strength measurement. [Modes for carrying out the invention]

[0021] [Barrier laminate] The barrier laminate according to the present invention comprises a paper substrate layer, a barrier layer, and a sealant layer in that order, and an acid-modified polyolefin layer is provided between the paper substrate layer and the barrier layer, or between the barrier layer and the sealant layer. The barrier layer is a barrier film comprising a substrate film, a first inorganic oxide vapor deposition layer, and a barrier coat layer in that order. The acid-modified polyolefin layer is in contact with the barrier coat layer of the barrier film.

[0022] In one embodiment, the barrier laminate comprises an acid-modified polyolefin layer between the substrate layer and the barrier layer, and between the barrier layer and the sealant layer, and an olefin-unsaturated carboxylic acid copolymer layer between the other. The acid-modified polyolefin layer is in contact with the barrier coat layer of the barrier film. The olefin-unsaturated carboxylic acid copolymer layer is in contact with the second inorganic oxide vapor deposition layer.

[0023] The layer structure of the barrier laminate according to the present invention will be described below with reference to Figures 1 to 4. Figures 1 to 4 are schematic cross-sectional views showing one embodiment of the barrier laminate according to the present invention.

[0024] In one embodiment, the barrier laminate 20 comprises, as shown in Figure 1, a paper substrate layer 21, an acid-modified polyolefin layer 24, a barrier layer 22, and a sealant layer 23 in that order. The barrier layer 22 is composed of a barrier film 10 comprising, in that order, a substrate film 11, a first inorganic oxide vapor deposition layer 12, and a barrier coat layer 13. The acid-modified polyolefin layer 24 is in contact with the barrier coat layer 13.

[0025] In one embodiment, the barrier laminate 20 comprises, in order, a paper substrate layer 21, a barrier layer 22, an acid-modified polyolefin layer 24, and a sealant layer 23, as shown in Figure 2. The barrier layer 22 is composed of a barrier film 10 comprising, in order, a substrate film 11, a first inorganic oxide vapor deposition layer 12, and a barrier coat layer 13. The acid-modified polyolefin layer 24 is in contact with the barrier coat layer 13.

[0026] In one embodiment, as shown in Figure 3, the barrier laminate 20 comprises a paper substrate layer 21, an acid-modified polyolefin layer 24, a barrier layer 22, an olefin-unsaturated carboxylic acid copolymer layer 25, and a sealant layer 23 in that order. The barrier layer 22 is composed of a barrier film 10 comprising a second inorganic oxide vapor deposition layer 14, a substrate film 11, a first inorganic oxide vapor deposition layer 12, and a barrier coat layer 13 in that order. The acid-modified polyolefin layer 24 is in contact with the barrier coat layer 13. The olefin-unsaturated carboxylic acid copolymer layer 25 is in contact with the second inorganic oxide vapor deposition layer 14.

[0027] In one embodiment, as shown in Figure 4, the barrier laminate 20 comprises a paper substrate layer 21, an olefin-unsaturated carboxylic acid copolymer layer 25, a barrier layer 22, an acid-modified polyolefin layer 24, and a sealant layer 23 in that order. The barrier layer 22 is composed of a barrier film 10 comprising a second inorganic oxide vapor deposition layer 14, a substrate film 11, a first inorganic oxide vapor deposition layer 12, and a barrier coat layer 13 in that order. The acid-modified polyolefin layer 24 is in contact with the barrier coat layer 13. The olefin-unsaturated carboxylic acid copolymer layer 25 is in contact with the second inorganic oxide vapor deposition layer 14.

[0028] The layer configuration of the barrier laminate 20 described above can be combined as appropriate.

[0029] In the barrier laminate according to the present invention, the acidity permeability before bending, measured in accordance with JIS K7126-1:2006 under conditions of 23°C and 90% RH, is preferably 1.0 cc / m³. 2 It is less than or equal to atm·day, and more preferably 0.5cc / m 2 It is less than or equal to atm·day, and more preferably 0.25 cc / m 2 It is less than or equal to atm·day, and more preferably 0.15cc / m 2 The value is less than or equal to 1.0m·day. If the oxygen permeability of the barrier laminate meets the above numerical range, it has suitable oxygen barrier properties, and therefore, when the barrier laminate is used in packaging products, adverse effects on the contents of the packaging product can be suppressed.

[0030] In the barrier laminate according to the present invention, the adhesion strength between the barrier coat layer and the acid-modified polyolefin layer is preferably 4.5 N / 15 mm or more, and more preferably 5.0 N / 15 mm or more. While a higher adhesion strength between the barrier coat layer and the acid-modified polyolefin layer is preferable, the adhesion strength between the barrier coat layer and the acid-modified polyolefin layer may be, for example, 20.0 N / 15 mm or less. The method for measuring adhesion strength will be explained in the examples described later.

[0031] The thickness of the barrier laminate according to the present invention is preferably 50 μm or more and 800 μm or less, and more preferably 100 μm or more and 600 μm or less.

[0032] The following describes each layer that the barrier laminate according to the present invention may comprise.

[0033] <Barrier layer (barrier film)> The barrier layer of the barrier laminate according to the present invention is a barrier film. The barrier film comprises, in this order, a barrier coat layer, a first inorganic oxide vapor deposition layer, and a base film. The barrier film may further comprise a second inorganic oxide vapor deposition layer. The following describes the base film, the first inorganic oxide vapor deposition layer, the second inorganic oxide vapor deposition layer, and the barrier coat layer.

[0034] (Base film) The base film is not particularly limited, but any resin film can be used that can withstand the conditions for forming an inorganic oxide vapor-deposited film and maintain its film properties well without impairing them. Examples of base films include polyolefins such as polyethylene and polypropylene, cyclic polyolefins, polystyrene, acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS), (meth)acrylic resin, polycarbonate, polyvinyl alcohol, ethylene-vinyl ester copolymer saponified, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyamides such as various types of nylon, polyurethane, acetal resin, and cellulose resin. Among the above resin films, polyester, polyolefin, or polyamide films are preferred, and polyester films are particularly preferred. The base film may also be a laminated film using two or more of these films. In this specification, "(meth)acrylic" means that it encompasses both "acrylic" and "methacrylic."

[0035] The base film can be any of the following: an unstretched film of the above-mentioned resin, or a film of the resin stretched in one or two axes. In this specification, the term "unstretched film" includes not only films that have not been stretched at all, but also films that have been slightly stretched due to the tension applied during film formation.

[0036] The resin referred to in the above-mentioned film may be a resin derived from fossil fuels, a resin derived from biomass, or a mixture thereof. Alternatively, recycled resin, virgin resin, or a mixture thereof may be used. "Fossil fuel-derived resin" refers to a resin obtained from raw materials containing only monomers derived from fossil fuels. A "biomass-derived resin" is a material obtained from raw materials containing monomers derived from biomass. Taking polyester, which is composed of diol units and dicarboxylic acid units, as an example, a biomass-derived polyester is a polyester in which at least one of the diol units and dicarboxylic acid units contains monomer units derived from biomass. "Recycled resin" refers to resin obtained by mechanically or chemically recycling resin products. "Virgin resin" refers to resin that has not been recycled.

[0037] As films of the various resins mentioned above, for example, films of the various resins can be manufactured by using one or more of the above-mentioned resins and employing film-forming methods such as extrusion, casting, T-die, cutting, or inflation to form films of the above-mentioned resins individually, or by using two or more types of resins to form multilayer co-extruded films, or by using two or more types of resins and mixing them before film formation. Furthermore, if necessary, films of the various resins that have been stretched in one or two axes using methods such as the tenter method or the tubular method can be used.

[0038] The thickness of the various resin films is preferably 6 μm to 2000 μm, and more preferably 9 μm to 100 μm.

[0039] Using one or more of the above-mentioned resins, various plastic compounding agents and additives can be added during film formation to improve or modify the film's processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, antifungal properties, electrical properties, strength, etc. The amount of these additives can range from trace amounts to tens of percent, depending on the purpose.

[0040] In the above, common additives that can be used include, for example, lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments. Furthermore, modifying resins can also be used.

[0041] The base film may be pre-treated before forming the inorganic oxide vapor deposition layer. This can improve adhesion to the inorganic oxide vapor deposition layer. Similarly, surface treatment can be applied to the vapor deposition layer to improve adhesion to the gas barrier coating film. Examples of such surface treatments include pre-treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, and oxidation treatment using chemicals. Among these surface treatments, corona treatment and plasma treatment are particularly preferred. For example, plasma treatment involves using plasma gas generated by ionizing a gas with an arc discharge to modify the surface. Inorganic gases such as oxygen, nitrogen, argon, and helium can be used as plasma gases. For example, by performing plasma treatment in-line, it is possible to remove moisture, dust, etc. from the surface of the substrate film, as well as perform surface treatments such as smoothing and activation of the surface. Furthermore, plasma treatment can be performed after deposition to improve adhesion. In this invention, it is preferable to perform plasma discharge treatment considering the plasma output, type of plasma gas, amount of plasma gas supplied, treatment time, and other conditions. Furthermore, devices such as DC glow discharge, high-frequency discharge, and microwave discharge can be used to generate plasma. Plasma treatment can also be performed by atmospheric pressure plasma treatment.

[0042] The base film can also be surface-treated by applying a primer coat, undercoat, or vapor-deposited anchor coat, etc., as desired. As a coating agent, for example, a resin composition in which polyester, polyamide, polyurethane, epoxy resin, phenolic resin, (meth)acrylic resin, polyvinyl acetate, polyethylene, polypropylene, or other polyolefins or copolymers thereof or modified resins, cellulose resin, etc., can be used as the main component of the vehicle.

[0043] (First inorganic oxide vapor deposition layer) The first inorganic oxide deposition layer is a deposition film containing inorganic oxides formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD).

[0044] Inorganic oxides are not particularly limited, but examples include oxides of silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, and yttrium. The vapor-deposited film may use two or more of these oxides. Among these, the first inorganic oxide vapor-deposited layer is preferably a vapor-deposited film of aluminum oxide or silicon oxide. Inorganic oxides are often abbreviated as, for example, AlO X SiO X MO X (In the formula, M represents an inorganic element, and the value of X has a different range depending on the inorganic element.) In the present invention, from the viewpoint of transparency and gas barrier properties, when M is aluminum (Al), the value of X is preferably 0.5 to 2.0, and when M is silicon (Si), the value of X is preferably 1 to 2. The first inorganic oxide vapor deposition layer may comprise two or more vapor-deposited films. If it comprises two or more vapor-deposited films, each film may have the same composition or different compositions.

[0045] As the first inorganic oxide deposition layer, it is preferable to provide an aluminum oxide deposition film by physical vapor deposition due to its ease of handling as a deposition material. The aluminum oxide deposition film formed by physical vapor deposition exhibits excellent adhesion to the surface of the gas barrier coating film. Examples of physical vapor deposition methods include vacuum deposition, sputtering, ion plating, and ion cluster beam deposition.

[0046] Specifically, a deposited film can be formed by a vacuum deposition method using aluminum or its oxide as a raw material, heating it to vaporize it, and depositing it onto one side of a substrate film; an oxidation reaction deposition method using aluminum or its oxide as a raw material, introducing oxygen to oxidize it, and depositing it onto one side of a substrate film; and a plasma-assisted oxidation reaction deposition method in which the oxidation reaction is assisted by plasma. The heating method for the deposition material can be, for example, resistance heating, high-frequency induction heating, or electron beam heating (EB).

[0047] When the first inorganic oxide vapor deposition layer is a silicon oxide vapor deposition film, it is preferable to provide the silicon oxide vapor deposition film by chemical vapor deposition (CVA) from the viewpoint of flexibility and gas barrier properties. Examples of CVA methods include plasma CVA, low-temperature plasma CVA, thermochemical vapor deposition, and photochemical vapor deposition. Specifically, a silicon oxide vapor deposition film can be formed on one side of a substrate film by low-temperature plasma CVA, using a monomer gas for deposition such as an organosilicon compound as a raw material, an inert gas such as argon or helium as a carrier gas, and oxygen gas as an oxygen supply gas, utilizing a low-temperature plasma generator. Examples of low-temperature plasma generators include high-frequency plasma, pulsed-wave plasma, and microwave plasma generators. It is preferable to use a high-frequency plasma generator because it can obtain a highly active and stable plasma.

[0048] For example, the monomer gas used for vapor deposition of organosilicon compounds to form silicon oxide vapor-deposited films can be 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane, etc. Among these, 1,1,3,3-tetramethyldisiloxane or hexamethyldisiloxane are particularly preferred as raw materials due to their ease of handling and the characteristics of the formed continuous film. In the above, for example, argon gas, helium gas, etc. can be used as the inert gas.

[0049] A silicon dioxide vapor-deposited film is primarily composed of silicon dioxide, but may also contain at least one compound consisting of one or more elements from carbon, hydrogen, nitrogen, silicon, or oxygen, via chemical bonding or other means. For example, it may contain compounds with CH bonds, compounds with Si-H bonds, or carbon units in the form of graphite, diamond, or fullerene. Furthermore, it may also contain organosilicon compounds or their derivatives as raw materials via chemical bonding or other means. Examples include hydrocarbons with CH3 moieties, hydrosilica such as SiH3 silyl and SiH2 silylene, and hydroxyl group derivatives such as SiH2OH silanol. In addition, the types and amounts of compounds contained in the silicon dioxide vapor-deposited film can be changed by altering the conditions of the vapor deposition process.

[0050] The thickness of the first inorganic oxide deposition layer is preferably 3 to 100 nm, more preferably 5 to 50 nm, and even more preferably 8 to 30 nm.

[0051] (Second inorganic oxide deposited layer) The second inorganic oxide deposition layer is a deposited film containing an inorganic oxide formed by chemical vapor deposition or physical vapor deposition, similar to the first inorganic oxide deposition layer. As the inorganic oxide, the same inorganic oxide as that of the first inorganic oxide deposition layer can be used. The second inorganic oxide deposition layer may include two or more deposited films. When two or more deposited films are provided, each deposited film may have the same composition or different compositions. When the barrier film includes the first inorganic oxide deposition layer and the second inorganic oxide deposition layer, each deposition layer may have the same structure or different structures.

[0052] The thickness of the second inorganic oxide deposition layer is preferably 3 to 100 nm, more preferably 5 to 50 nm, and still more preferably 8 to 30 nm.

[0053] (Barrier coating layer) The barrier coating layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer. By making the barrier coating layer such a cured film, the barrier coating layer has gas barrier properties.

[0054] The barrier coating layer can be formed, for example, by the following gas barrier coating film. The gas barrier coating film is a coating film that retains gas barrier properties in a high-temperature and high-humidity environment, and has the general formula R 1 <00000​​​​​​​​​​​​​​​​​​​​​R is an alkyl group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, which may be branched. 1 Examples of such groups include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, and n-octyl group.

[0056] The above general formula R 1 n M(OR 2 ) m Medium, R 2 R is an alkyl group having 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 4 carbon atoms, which may be branched. 1 Examples include methyl groups, ethyl groups, n-propyl groups, i-propyl groups, n-butyl groups, sec-butyl groups, etc. Note that multiple (OR) groups can be present in the same molecule. 2 If ) exists, (OR 2 ) may be the same or different.

[0057] The above general formula R 1 n M(OR 2 ) m Examples of metal atoms represented by M include silicon, zirconium, titanium, and aluminum.

[0058] The above general formula R 1 n M(OR 2 ) m As the alkoxide represented by , at least one of a partial hydrolysate of an alkoxide or a hydrolyzed condensate of an alkoxide can be used. Furthermore, the partial hydrolysate of the alkoxide is not limited to one in which all alkoxy groups are hydrolyzed, but may include one in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. Moreover, as the hydrolyzed condensate, a dimer or more of a partial hydrolyzed alkoxide, specifically a 2-6 mer, may be used.

[0059] In the present invention, the above general formula R 1 n M(OR2 ) m As the alkoxide represented by , alkoxysilanes in which M is Si can be suitably used. Suitable alkoxysilanes include, for example, tetramethoxysilane Si(OCH3)4, tetraethoxysilane Si(OC2H5)4, tetrapropoxysilane Si(OC3H7)4, tetrabutoxysilane Si(OC4H9)4, methyltrimethoxysilane CH3Si(OCH3)3, methyltriethoxysilane CH3Si(OC2H5)3, dimethyldimethoxysilane(CH3)2Si(OCH3)2, and dimethyldiethoxysilane(CH3)2Si(OC2H5)2. In the present invention, condensed polymers of these alkoxysilanes can also be used, specifically, for example, polytetramethoxysilane and polytetraethoxysilane can be used.

[0060] The water-soluble polymer used in this invention can be polyvinyl alcohol or ethylene-vinyl alcohol copolymer, either individually or in combination. In this invention, by using polyvinyl alcohol and / or ethylene-vinyl alcohol copolymer, physical properties such as gas barrier properties, water resistance, weather resistance, and others can be significantly improved.

[0061] Generally, polyvinyl alcohol obtained by saponifying polyvinyl acetate can be used. The polyvinyl alcohol can be partially saponified polyvinyl alcohol in which several tens of percent of acetate groups remain, fully saponified polyvinyl alcohol in which no acetate groups remain, or modified polyvinyl alcohol in which the OH groups have been modified; it is not particularly limited.

[0062] As the ethylene-vinyl alcohol copolymer, a saponified copolymer of ethylene and vinyl acetate, i.e., one obtained by saponifying an ethylene-vinyl acetate random copolymer, can be used. For example, it includes, but is not particularly limited to, partially saponified copolymers in which several tens of mole percent of acetate groups remain, and fully saponified copolymers in which only a few mole percent of acetate groups remain or none remain. However, from the viewpoint of gas barrier properties, it is preferable to use one with a preferred degree of saponification of 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more. The content of repeating units derived from ethylene in the above ethylene-vinyl alcohol copolymer (hereinafter also referred to as "ethylene content") is usually preferably 0 to 50 mol%, preferably 20 to 45 mol%.

[0063] Furthermore, a silane coupling agent may be added to the barrier coat layer. For example, silane coupling agents having reactive groups such as alkoxy groups (methoxy, ethoxy, etc.), acetoxy groups, amino groups, epoxy groups, etc., can be used.

[0064] Furthermore, as the organic solvent used in the above gas barrier composition, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol, etc., can be used. The polyvinyl alcohol and / or ethylene-vinyl alcohol copolymer is preferably handled in a dissolved state in a coating solution containing the alkoxide and silane coupling agent, etc., and can be appropriately selected from the above organic solvents. For example, when using polyvinyl alcohol and ethylene-vinyl alcohol copolymer in combination, it is preferable to use n-butanol.

[0065] In the barrier laminate according to the present invention, when the surface of the barrier coat layer is measured by X-ray photoelectron spectroscopy (XPS), the ratio of metal atoms (M) to carbon atoms (C) (M / C) is 1.35 or less. This improves adhesion with the acid-modified polyolefin layer, which will be described later. The reason for this is thought to be as follows.

[0066] In the barrier laminate according to the present invention, the barrier coat layer is in contact with the acid-modified polyolefin layer. Bonds and / or intermolecular forces (particularly hydrogen bonds) are generated between the polar groups of the water-soluble polymer in the barrier coat layer and the polar groups of the acid-modified polyolefin. Here, since the barrier coat layer is a cured film of the hydrolysis product of a metal alkoxide and a water-soluble polymer, the metal atoms are atoms derived from the metal alkoxide, and the carbon atoms are atoms derived from the water-soluble polymer. Therefore, this ratio indirectly represents the ratio of the hydrolysis product of the metal alkoxide to the water-soluble polymer used to form the barrier coat layer. By setting this ratio to 1.35 or less, the amount of water-soluble polymer-derived components in the barrier coat layer increases, and the bonding and / or intermolecular forces between the polar groups of the water-soluble polymer in the barrier coat layer and the polar groups of the acid-modified polyolefin increase. This is thought to improve the adhesion strength between the barrier coat layer and the layer in contact with the barrier coat layer. Furthermore, by setting this ratio to 1.35 or less, the proportion of water-soluble polymers increases, which can improve the flexibility of the barrier coat layer.

[0067] The ratio of metal atoms to carbon atoms can be measured by narrow-scan analysis under the following measurement conditions using X-ray photoelectron spectroscopy (XPS). (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: AlKα (monochromatic X-ray, hν=1486.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): Approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ionic species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching area: 10mmφ Ion sputtering was performed for 20 seconds + 20 seconds + 20 seconds + 20 seconds (total 80 seconds), and the spectrum was collected. The ratio of metal atoms to carbon atoms is the average value over the ion sputtering time range of 20 to 80 seconds in the above spectrum.

[0068] The above ratio (M / C) is, for example, 0.80 or more, may be 0.85 or more, or 0.90 or more. The ratio (M / C) is, for example, 1.35 or less, may be 1.15 or less, or 0.99 or less. The range of the ratio (M / C) may be constructed by combining any one candidate upper limit and any one candidate lower limit. For example, the ratio (M / C) is preferably 0.80 or more and 1.35 or less, more preferably 0.80 or more and 1.15 or less. By setting this ratio to 0.80 or higher, the bonding and / or intermolecular forces between the metal element and the polar groups of the water-soluble polymer can be increased. As a result, the barrier coating layer becomes denser, and the gas barrier properties of the barrier laminate can be improved.

[0069] In the barrier laminate according to the present invention, the thickness of the barrier coat layer is 155 nm or more. Surprisingly, by making the thickness of the barrier coat layer 155 nm or more, the adhesion strength between the barrier coat layer and the acid-modified polyolefin layer can be improved. The reason for this is not entirely clear, but it is thought that by increasing the thickness of the barrier coat layer, the proportion of polar groups of the water-soluble polymer in the barrier coat layer that are exposed on the surface of the barrier coat layer increases, and the bonding and / or intermolecular forces between the polar groups of the water-soluble polymer in the barrier coat layer and the polar groups of the acid-modified polyolefin increase. Furthermore, by making the thickness of the barrier coat layer 155 nm or more, the gas barrier properties of the barrier laminate can be improved.

[0070] In the barrier laminate according to the present invention, the thickness of the barrier coating layer is a value measured by cross-sectional observation. Cross-sectional observation is performed using a scanning electron microscope.

[0071] Here, we will explain the specific method for measuring the thickness of the barrier coating layer using a scanning electron microscope. First, prepare a test specimen by cutting a sample (such as a barrier laminate) to approximately 20 mm x 20 mm. Next, place the test specimen in a special mold and fill the mold with a curable resin such as epoxy resin. Then, allow the curable resin to harden and remove the hardened material. Next, cut the hardened material in the thickness direction of the test specimen, passing through the center of the test specimen within the hardened material. This exposes the cross-section of the test specimen (the surface where the cross-section of the barrier coat layer is exposed, perpendicular to the lamination direction of each layer) to the surface of the hardened material. Cutting can be performed using a commercially available rotary microtome or similar device. Next, ultrathin sections (less than 100 μm thick) are taken from the surface of the hardened material using an ultramicrotome or similar instrument. The cross-section of the exposed barrier coat layer in these ultrathin sections is observed using a scanning electron microscope, and the thickness of the barrier coat layer is measured. The thickness of the barrier coat layer is the average value measured at the center of each section when the cross-section of the barrier coat layer is divided into 10 equal parts along its length. For scanning electron microscopes, the Hitachi High-Tech SU8000 can be used. For ultramicrotomes, the Leica Microsystems EM UC7 can be used. Unless otherwise specified, measurements will be performed in an environment of 50% relative humidity and 23°C.

[0072] The thickness of the barrier coat layer is 270 nm or less, may be 250 nm or less, or 220 nm or less. The range of the barrier coat layer thickness may be configured by combining any one candidate upper limit and any one candidate lower limit. For example, the thickness of the barrier coat layer is preferably 155 nm or more and 270 nm or less, more preferably 155 nm or more and 250 nm or less, and even more preferably 155 nm or more and 220 nm or less. By making the barrier coating layer thickness 270 nm or less, the flexibility of the barrier coating layer can be improved, and the decrease in the gas barrier properties of the barrier laminate after bending can be suppressed.

[0073] In the barrier laminate according to the present invention, the hardness of the barrier coat layer is, for example, 1.25 GPa or less, may be 1.15 GPa or less, or 1.09 GPa or less. The hardness of the barrier coat layer is, for example, 0.70 GPa or more, may be 0.80 GPa or more, or 0.90 GPa or more. The range of hardness of the barrier coat layer may be configured by combining any one candidate upper limit and any one candidate lower limit. For example, the hardness of the barrier coat layer is preferably 1.25 GPa or less, more preferably 0.70 GPa or more and 1.25 GPa or less, even more preferably 0.80 GPa or more and 1.15 GPa or less, and even more preferably 0.90 GPa or more and 1.09 GPa or less. By setting the hardness of the barrier coating layer to 1.25 GPa or less, the flexibility of the barrier coating layer can be improved, and the decrease in the gas barrier properties of the barrier laminate after bending can be suppressed. By increasing the hardness of the barrier coating layer to 0.70 GPa or higher, a denser barrier coating layer can be created, thereby improving the gas barrier properties of the barrier laminate.

[0074] In the barrier film of the present invention, the plastic deformation rate of the barrier coat layer is preferably 35% or more, more preferably 40% or more, and even more preferably 45% or more. By setting the plastic deformation rate of the barrier coating layer to 35% or more, the flexibility of the barrier coating layer can be improved, and the decrease in gas barrier properties due to bending of the barrier film can be suppressed.

[0075] In the barrier film of the present invention, the composite modulus of the barrier coat layer is, for example, 7.5 GPa or more, may be 7.7 GPa or more, or 8.0 GPa or more. The composite modulus of the barrier coat layer is, for example, 9.5 GPa or less, may be 9.2 GPa or less, or 9.0 GPa or less. The range of the composite modulus of the barrier coat layer may be configured by combining any one candidate upper limit and any one candidate lower limit. For example, the composite modulus of the barrier coat layer is preferably 7.5 GPa or more and 9.5 GPa or less, more preferably 7.7 GPa or more and 9.2 GPa or less, and even more preferably 8.0 GPa or more and 9.0 GPa or less. By setting the composite elastic modulus of the barrier coating layer to 9.5 GPa or less, the flexibility of the barrier coating layer can be improved, and the decrease in gas barrier properties due to bending of the barrier film can be suppressed. By setting the composite elastic modulus of the barrier coating layer to 7.5 GPa or higher, a denser barrier coating layer can be created, improving the initial gas barrier properties.

[0076] The hardness of the barrier coating layer is measured by nanoindentation. In nanoindentation, an indenter is used to measure 1 μm 2 By indenting the film into a microscopic region of less than 1 mm, the plasticity and elasticity of the film, as well as the resulting deformation rate and Young's modulus, can be quantitatively evaluated. The hardness of the barrier coat layer is calculated by the following equation (1). The plastic deformation rate of the barrier coat layer is calculated from the results of nanoindentation measurement (load-displacement curve) by the following equation (2). Furthermore, the composite elastic modulus of the barrier coat layer is calculated by the following equation (3). Hardness=P max / A ···(1) Plastic deformation rate = W plast / W total ×100 ···(2)

number

[0077] Here, we will explain the specific measurement method for the hardness, plastic deformation rate, and composite modulus of the barrier coating layer using the nanoindentation method. First, prepare a test specimen by cutting a sample (such as a barrier laminate) to approximately 20 mm x 20 mm. Next, place the test specimen in a special mold and fill the mold with a curable resin such as epoxy resin. Then, allow the curable resin to harden and remove the hardened material. Next, cut the hardened material in the thickness direction of the test specimen, passing through the center of the test specimen within the hardened material. This exposes the cross-section of the test specimen (the surface where the cross-section of the barrier coat layer is exposed, perpendicular to the lamination direction of each layer) to the surface of the hardened material. Cutting can be performed using a commercially available rotary microtome or similar device. Next, the hardness, plastic deformation rate, and composite modulus of the cross-section of the barrier coat layer are measured using the nanoindentation method. First, the indenter is placed against the cross-section of the barrier coat layer and pressed in from the cross-section to a load of 15 μN over 10 seconds, and held in that position for 5 seconds. Then, the load is removed over 10 seconds. This allows the maximum load P to be measured. max The contact projection area A at maximum depth and the load-displacement curve are obtained. Note that the maximum load P max The contact projection area A at maximum depth is the average value measured at the center of each portion when the cross-section of the barrier coat layer is divided into five equal parts in the length direction. A nanoindenter (HYSITRON's "TI950 TriboIndenter") can be used to measure hardness, plastic deformation rate, and composite modulus. A Cube Corner indenter can be used as the indenter for the nanoindenter. Unless otherwise specified, measurements should be performed in an environment of 50% relative humidity and 23°C.

[0078] The barrier coat layer can be formed by the following method. First, the above metal alkoxide, the above water-soluble polymer, and optionally a silane coupling agent, a sol-gel catalyst, an acid, water, an organic solvent, etc. are mixed to prepare a gas barrier composition (barrier coating liquid). Next, the gas barrier composition is applied onto the first inorganic oxide deposition layer. The gas barrier composition can be applied in one or more applications using methods such as roll coating (including gravure roll coaters), spray coating, spin coating, dipping, brushing, barcode application, or applicator, to form a coated film.

[0079] Next, the film coated with the gas barrier composition is heated and dried at a temperature below the melting point of the base film for about 1 second to 10 minutes. This causes polycondensation, forming a barrier coat layer. Alternatively, the barrier coat composition may be applied on top of the first inorganic oxide vapor deposition layer to create two or more layers of coating film, and then heated and dried at a temperature below the melting point of the base film for about 1 second to 10 minutes to form a composite polymer layer with two or more layers of barrier coat. In this way, one or more barrier coat layers made of the barrier coat composition can be formed.

[0080] A barrier coating layer having the above hardness can be formed by appropriately adjusting the solid content ratio (IO value) of the metal alkoxide to the water-soluble polymer in the barrier coating solution, and / or the heating and drying temperature. The solid content ratio (IO value) of metal alkoxide to water-soluble polymer in the barrier coating liquid is preferably 1.25 to 2.00, and more preferably 1.50 to 1.75. The heating and drying temperature is preferably 130°C or higher and less than 200°C, and more preferably 140°C or higher and 180°C or lower.

[0081] <Paper base layer> The paper substrate layer can be any paper substrate depending on the application. For use as a paper container after box formation, the paper substrate must have sufficiently high formability, flexibility, rigidity, stiffness, and strength. Such paper substrates include, for example, high-size bleached or unbleached paper substrates, or various paper substrates such as pure white roll paper, kraft paper, cardboard, and processed paper, with a basis weight of approximately 80-600 g / m². 2 A material of a certain quality, preferably with a basis weight of approximately 100-450 g / m². 2 A suitable material of a certain degree can be used.

[0082] The paper substrate layer may have a printed layer on its surface, and the image formed on the printed layer is not particularly limited and may represent characters, patterns, symbols, or combinations thereof. The method for forming the printed layer is not particularly limited, and examples include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing.

[0083] <Sealant layer> The sealant layer can be formed from a thermoplastic resin that has heat-sealing properties. Examples of thermoplastic resins include polyolefins. Specifically, these include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymers polymerized using metallocene catalysts, and ethylene-propylene copolymers such as random or block copolymers of ethylene and propylene.

[0084] A sealant layer can be formed by melt-extruding one or more of the above-mentioned thermoplastic resins onto a barrier layer via an anchor coat layer or the like, optionally, using an extruder or the like. Alternatively, a sealant layer can be formed together with the acid-modified polyolefin layer, olefin-unsaturated carboxylic acid copolymer layer, or adhesive layer by melt-co-extruding the thermoplastic resin with the resin constituting the acid-modified polyolefin layer, olefin-unsaturated carboxylic acid copolymer layer, or adhesive layer. Alternatively, a film or sheet of the above-mentioned thermoplastic resin can be manufactured in advance using one or more of the above-mentioned thermoplastic resins, and the manufactured film or sheet can be dry-laminated or sand-laminated onto the barrier layer via an acid-modified polyolefin layer, an olefin-unsaturated carboxylic acid copolymer layer, or an adhesive layer to form a sealant layer.

[0085] To obtain the desired properties, the thermoplastic resin may be blended with other resins. In addition, various additives, such as antioxidants, UV absorbers, antistatic agents, antiblocking agents, lubricants (fatty acid amides, etc.), flame retardants, inorganic or organic fillers, dyes, pigments, etc., can be optionally added.

[0086] The thickness of the sealant layer is not particularly limited, but from the viewpoint of sealing performance, it is preferably 10 μm to 300 μm, and more preferably 20 μm to 100 μm.

[0087] <Acid-modified polyolefin layer> The acid-modified polyolefin layer can be formed from acid-modified polyolefins. Acid-modified polyolefins are polymers modified by block polymerization or graft polymerization of polyolefins with an acid component. Bonds and / or intermolecular forces are generated between the polar groups of the water-soluble polymer in the barrier coat layer and the polar groups of the acid-modified polyolefin. Therefore, by including an acid-modified polyolefin layer in contact with the barrier coat layer in the barrier laminate, the adhesion strength between these layers can be improved.

[0088] Polyolefins that can be acid-modified include polyethylene and polypropylene, copolymers obtained by copolymerizing olefins with polar molecules such as (meth)acrylic acid, and polymers such as cross-linked polyolefins. Examples of acid components used in acid modification include carboxylic acids or their anhydrides, such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0089] Acid-modified polyolefins may also be acid-modified cyclic polyolefins. Acid-modified cyclic polyolefins are polymers obtained by copolymerizing a portion of the monomers constituting a cyclic polyolefin with an acid component, or by block polymerization or graft polymerization of an acid component to a cyclic polyolefin.

[0090] The acid-modified polyolefin is preferably a polyolefin modified with an anhydride of an unsaturated dicarboxylic acid, and more preferably a maleic anhydride-modified polyolefin. When the water-soluble polymer in the barrier coat layer has a hydroxyl group, such anhydride of a carboxylic acid opens its ring and directly bonds with the hydroxyl group, thereby further improving the adhesion between the layers.

[0091] One or more of the above-mentioned acid-modified polyolefins can be melt-extruded onto a barrier coat layer or the like using an extruder to form an acid-modified polyolefin layer.

[0092] Acid-modified polyolefins can also be used in blends with other resins. Furthermore, various additives, such as antioxidants, UV absorbers, antistatic agents, antiblocking agents, lubricants (fatty acid amides, etc.), flame retardants, inorganic or organic fillers, dyes, pigments, etc., can be optionally added.

[0093] The thickness of the acid-modified polyolefin layer is preferably 1 μm to 50 μm, and more preferably 2 μm to 20 μm.

[0094] <Olefin-unsaturated carboxylic acid copolymer layer> An olefin-unsaturated carboxylic acid copolymer layer can be formed by an olefin-unsaturated carboxylic acid copolymer. An olefin-unsaturated carboxylic acid copolymer is a compound that contains one or more olefins and one or more unsaturated carboxylic acids as monomer components. Bonds and / or intermolecular forces are generated between the inorganic elements constituting the inorganic oxide and the carboxyl groups present in the olefin-unsaturated carboxylic acid copolymer. Therefore, by including an olefin-unsaturated carboxylic acid copolymer layer in contact with the second inorganic oxide deposition layer in the barrier laminate, the adhesion strength between these layers can be improved.

[0095] Examples of olefins in olefin-unsaturated carboxylic acid copolymers include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene. Among these olefins, ethylene is particularly preferred.

[0096] Examples of unsaturated carboxylic acids in olefin-unsaturated carboxylic acid copolymers include acrylic acid, methacrylic acid, maleic acid, and fumaric acid. Among these unsaturated carboxylic acids, (meth)acrylic acid is particularly preferred.

[0097] The olefin-unsaturated carboxylic acid copolymer may contain an unsaturated carboxylic acid ester as a monomer component. Examples of unsaturated carboxylic acid esters include ester compounds of the above-mentioned unsaturated carboxylic acids. Among these, (meth)acrylic acid esters are particularly preferred.

[0098] The olefin-unsaturated carboxylic acid copolymer is preferably an olefin-acrylic acid copolymer or an olefin-methacrylic acid copolymer, and more preferably an ethylene-acrylic acid copolymer or an ethylene-methacrylic acid copolymer.

[0099] One or more of the above-mentioned olefin-unsaturated carboxylic acid copolymers can be melt-extruded onto a second inorganic oxide deposition layer or the like using an extruder to form an olefin-unsaturated carboxylic acid copolymer layer.

[0100] Olefin-unsaturated carboxylic acid copolymers can also be used in blends with other resins. Furthermore, various additives, such as antioxidants, UV absorbers, antistatic agents, antiblocking agents, lubricants (fatty acid amides, etc.), flame retardants, inorganic or organic fillers, dyes, pigments, etc., can be optionally added.

[0101] The thickness of the olefin-unsaturated carboxylic acid copolymer layer is preferably 1 μm to 50 μm, and more preferably 2 μm to 20 μm.

[0102] <Adhesive layer> The adhesive layer is an adhesive layer or adhesive resin layer formed to bond two layers together by lamination.

[0103] As the adhesive layer, for example, one-component or two-component curing or non-curing type laminating adhesives such as vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others, can be used, including solvent-based, water-based, or emulsion-type adhesives. The above adhesives can be applied using methods such as direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, fontein method, transfer roll coating, and others. The application rate is 0.1 g / m². 2 ~10g / m 2 (Dry state) is preferable, 1 g / m 2 ~5g / m 2 A (dry) state is preferable.

[0104] The adhesive resin layer contains a thermoplastic resin. The same thermoplastic resin as that used in the sealant layer can be used. The thickness of the adhesive resin layer is not particularly limited, but is preferably 1 μm to 50 μm, and more preferably 2 μm to 20 μm.

[0105] <Example of layer structure> An example of the layer configuration of the barrier laminate according to the present invention is shown below. In the following example, the left side represents the outside when the barrier laminate is used in a packaged product, and the right side represents the inside. In the following example, the symbol " / " represents the boundary between each layer. • Paper base layer / Polyethylene / Acid-modified polyolefin layer / Barrier coat layer / Aluminum oxide vapor-deposited film / Polyethylene terephthalate film / Aluminum oxide vapor-deposited film / Olefin-unsaturated carboxylic acid copolymer layer / Polyethylene • Paper base layer / Polyethylene / Olefin-unsaturated carboxylic acid copolymer layer / Aluminum oxide vapor-deposited film / Polyethylene terephthalate film / Aluminum oxide vapor-deposited film / Barrier coat layer / Acid-modified polyolefin layer / Polyethylene • Paper base layer / Polyethylene / Acid-modified polyolefin layer / Barrier coat layer / Silicon oxide vapor-deposited film / Polyethylene terephthalate film / Aluminum oxide vapor-deposited film / Olefin-unsaturated carboxylic acid copolymer layer / Polyethylene • Paper base layer / Polyethylene / Olefin-unsaturated carboxylic acid copolymer layer / Aluminum oxide vapor-deposited film / Polyethylene terephthalate film / Silicon oxide vapor-deposited film / Barrier coat layer / Acid-modified polyolefin layer / Polyethylene

[0106] [Packaging products] The packaging product according to the present invention comprises a barrier laminate according to the present invention. Examples of packaging products include paper containers and packaging bags.

[0107] Below, an embodiment of the packaging product according to the present invention will be described using a paper container and a packaging bag as examples.

[0108] <Paper container> Figure 5 is a schematic perspective view showing one embodiment of a paper container, which is an example of a packaging product according to the present invention. As shown in Figure 5, the paper container 30 has a rectangular cylindrical body 31 including the sides, a rectangular plate-shaped bottom 32, and an upper part 33.

[0109] The upper part 33 has a pair of opposing inclined plates 34 and a pair of folded portions 35 located between the inclined plates 34 and folded between them. Each of the pair of inclined plates 34 is provided with an adhesive tab 36 at its upper end, and the pair of inclined plates 34 are bonded to each other by the adhesive tabs 36 at their respective upper ends. Alternatively, a spout may be attached to one of the inclined plates 34 and the spout may be sealed with a cap.

[0110] Since the paper container is made by forming a barrier laminate according to the present invention, it can be particularly suitable for use as a liquid paper container.

[0111] <Packaging bag>

[0112] Figure 6 is a schematic front view showing one embodiment of a packaging bag, which is an example of a packaging product according to the present invention. In Figure 6, hatching is applied to the seal portion. As shown in Figure 6, the packaging bag 40 has a seal portion that extends along the edges in four directions of the packaging bag 40. The packaging bag 40 shown in Figure 6 may also be called a four-sided sealed bag.

[0113] In addition to the four-sided sealed bag shown in Figure 6, other examples of packaging bags include standing pouches, pillow bags (gusseted sealed bags), two-sided sealed bags, three-sided sealed bags, side sealed bags, envelope-type sealed bags, pleated sealed bags, flat-bottom sealed bags, square-bottom sealed bags, and gusseted bags.

[0114] The contents of the packaged product according to the present invention are not particularly limited, but include, for example, liquids such as liquid milk, liquids containing solids such as amazake and soup, and solids such as dried goods. [Examples]

[0115] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0116] [Example 1] A 12 μm thick biaxially oriented polyethylene terephthalate (PET) film was prepared as the base film. Using a continuous deposition apparatus that separates a pretreatment section, where a plasma pretreatment device is placed on the surface of the PET film to be formed into a deposition layer, from a deposition section, plasma was introduced from a plasma supply nozzle in the pretreatment section under the following plasma conditions, and plasma pretreatment was performed at a transport speed of 600 m / min. Subsequently, in the deposition section, to which the film was continuously transported, an aluminum oxide deposition film (first inorganic oxide deposition layer) with a thickness of approximately 10 nm was formed on the plasma-treated surface under the following conditions using a reactive resistance heating method as the heating means for vacuum deposition. (Plasma pretreatment conditions) Plasma intensity: 150 W·sec / m 2 Plasma-forming gases: Argon 1200 (sccm), Oxygen 3000 (sccm) • Magnetic forming means: 1000 gauss permanent magnet • Voltage applied between pre-treatment drum and plasma supply nozzle: 340V • Vacuum level in the pre-treatment area: 3.8 Pa (Conditions for aluminum oxide film formation) ·Vacuum degree: 8.1×10 -2 Pa

[0117] Next, the prepared hydrolysis solution of composition A (solution A) was mixed with the prepared mixture of composition B (solution B) and stirred to obtain a colorless, transparent barrier coating composition. The solid content ratio of solution A to solution B (solution A / solution B) was 1.50 / 1. The compositions of solutions A and B are shown in Table 1.

[0118] [Table 1]

[0119] The barrier coating composition prepared above was coated onto an aluminum oxide vapor-deposited film of PET film by direct gravure printing. Subsequently, the film was heat-treated at 140°C for 30 seconds to form a barrier coating layer and obtain a barrier film.

[0120] Next, using a continuous deposition film deposition apparatus that separates a pretreatment section where a plasma pretreatment device is placed on the other side of the PET film from a film deposition section, plasma was introduced from a plasma supply nozzle under the aforementioned plasma conditions in the pretreatment section and plasma pretreatment was performed at a transport speed of 600 m / min. Subsequently, in the film deposition section, which was continuously transported, an aluminum oxide deposition film (second inorganic oxide deposition layer) with a thickness of approximately 10 nm was formed on the plasma-treated surface by reactive resistance heating as a heating means for vacuum deposition, thereby obtaining a barrier film (layer structure: "barrier coat layer / first inorganic oxide deposition layer / substrate film / second inorganic oxide deposition layer").

[0121] Using the obtained barrier film, the ratio of silicon atoms (Si) to carbon atoms (C) in the barrier coating layer (Si / C) was measured. Specifically, the ratio of silicon atoms to carbon atoms was measured by narrow-scan analysis using X-ray photoelectron spectroscopy (XPS) under the following measurement conditions. The measurement results are shown in Table 2. (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: AlKα (monochromatic X-ray, hν=1486.6eV) X-ray output: 150W (10kV 15mA) X-ray scanning area (measurement area): Approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ionic species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etching area: 10mmφ Ion sputtering was performed for 20 seconds + 20 seconds + 20 seconds + 20 seconds (total 80 seconds), and the spectrum was collected.

[0122] Next, the maleic acid-modified polyethylene and polyethylene were co-extruded onto the barrier coat layer of the obtained barrier film so that the barrier coat layer and the maleic acid-modified polyethylene were in contact. A paper substrate was then laminated via this using a sand lamination method. Next, ethylene-methacrylic acid copolymer (EMAA) and polyethylene were co-extruded onto the second inorganic oxide vapor deposition layer of the barrier film. This resulted in a barrier laminate comprising, in this order, a paper substrate layer (paper substrate), an adhesive resin layer (polyethylene), an acid-modified polyolefin layer (maleic acid-modified polyethylene), a barrier layer (layer structure: "barrier coat layer / first inorganic oxide vapor deposition layer / substrate film / second inorganic oxide vapor deposition layer"), an olefin-unsaturated carboxylic acid copolymer layer (EMAA), and a sealant layer (polyethylene). The thickness of the barrier laminate was 400 μm.

[0123] Using the barrier laminate of this embodiment, the hardness, plastic deformation rate, and composite modulus of the barrier coating layer were measured. Specifically, first, the barrier laminate was cut into approximately 20 mm x 20 mm sections to prepare test specimens. Next, the test specimens were placed in a special mold, and a curable resin such as epoxy resin was filled into the mold. Then, the curable resin was allowed to harden, and the hardened material was removed. Next, the hardened material was cut along the length of the test specimen, passing through the center of the test specimen within the hardened material. This exposed the cross-section of the test specimen (the surface where the cross-section of the barrier coat layer is exposed, perpendicular to the lamination direction of each layer) on the surface of the hardened material. The cutting was performed using a rotary microtome. Next, an indenter was placed against the cross-section of the barrier coat layer, and the indenter was pressed down from the cross-section to a load of 15 μN over 10 seconds, and held in that position for 5 seconds. Then, the load was removed over 10 seconds. This resulted in the maximum load P max The contact projection area A at maximum depth and the load-displacement curve were obtained. Maximum load P max The contact projection area A at maximum depth is the average value measured at the center of each portion when the cross-section of the barrier coat layer is divided into five equal parts in the longitudinal direction. From these average values, the hardness of the barrier coat layer was calculated using the above formula (1). In addition, the plastic work W was obtained from the load-displacement curve. plast and maximum work Wtotal The plastic deformation rate of the barrier coat layer was calculated using equation (2) above. Furthermore, the composite elastic modulus of the barrier coat layer was measured from the average value of the contact projected area A at the maximum depth using equation (3) above. The calculation results are shown in Table 2. For measuring the hardness, plastic deformation rate, and composite modulus of the barrier coat layer, a nanoindenter (HYSITRON's "TI950 TriboIndenter") was used. A Cube Corner indenter was used as the indenter for the nanoindenter. The measurements were performed under conditions of 50% relative humidity and 23°C.

[0124] The thickness of the barrier coating layer was measured using the barrier laminate of this embodiment. Specifically, first, similar to the hardness measurement described above, the test specimen was cured in a curable resin. The cured material was then cut along the thickness direction of the specimen, passing through the center of the specimen within the cured material, exposing the cross-section of the specimen to the surface of the cured material. Next, an ultrathin section (approximately 80 μm thick) was taken from the surface of this cured material using a microtome. The cross-section of the exposed barrier coat layer in this ultrathin section was observed using a scanning electron microscope, and the thickness of the barrier coat layer cross-section was measured. The thickness of the barrier coat layer was defined as the average value measured at the center of each section when the cross-section of the barrier coat layer was divided into 10 equal parts in the length direction. The thickness of the barrier coat layer is shown in Table 2. For the scanning electron microscope, we used the SU8000 manufactured by Hitachi High-Tech Corporation. For the microtome, we used the EM UC7 ultramicrotome manufactured by Leica Microsystems K.K.

[0125] In the following examples and comparative examples, the "ratio (Si / C)", "hardness", "plastic deformation rate", "composite elastic modulus", and "thickness" of the barrier coat layer were measured in the same manner as in Example 1.

[0126] [Example 2] A barrier laminate was prepared in the same manner as in Example 1, except that the ratio of solution A to solution B was 1.25 / 1 to create the barrier film.

[0127] [Example 3] A barrier laminate was prepared in the same manner as in Example 1, except that the ratio of solution A to solution B was 1.58 / 1 to create the barrier film.

[0128] [Example 4] A barrier laminate was prepared in the same manner as in Example 1, except that the ratio of solution A to solution B was 1.75 / 1 to create the barrier film.

[0129] [Example 5] A barrier laminate was prepared in the same manner as in Example 1, except that the barrier film was prepared by drying the barrier coating composition at 130°C.

[0130] [Example 6] A barrier laminate was prepared in the same manner as in Example 2, except that the barrier film was prepared by drying the barrier coating composition at 180°C.

[0131] [Example 7] A barrier laminate was prepared in the same manner as in Example 1, except that the barrier film was prepared by drying the barrier coating composition at 180°C.

[0132] [Example 8] A barrier laminate was prepared in the same manner as in Example 1, except that the barrier film was prepared by drying the barrier coating composition at 200°C.

[0133] [Example 9] A barrier laminate was fabricated in the same manner as in Example 1, except that the barrier film was made with a barrier coat layer thickness of 155 nm in the dry state.

[0134] [Example 10] A barrier laminate was fabricated in the same manner as in Example 1, except that the barrier film was made with a barrier coat layer thickness of 200 nm in the dry state.

[0135] [Example 11] A barrier laminate was fabricated in the same manner as in Example 1, except that the barrier film was made with a barrier coat layer thickness of 270 nm in the dry state.

[0136] [Example 12] A barrier laminate was fabricated in the same manner as in Example 1, except that the barrier film was made with a barrier coat layer thickness of 300 nm in the dry state.

[0137] [Example 13] A barrier film was prepared in the same manner as in Example 1. Next, EMAA and polyethylene were co-extruded onto the second inorganic oxide vapor deposition layer of the barrier film. A paper substrate was then laminated via this by a sand lamination method. Next, maleic anhydride-modified polyethylene and polyethylene were co-extruded onto the barrier coat layer of the barrier film. This resulted in a barrier laminate comprising, in this order, a paper substrate layer (paper substrate), an adhesive resin layer (polyethylene), an olefin-unsaturated carboxylic acid copolymer layer (EMAA), a barrier layer (layer structure: "second inorganic oxide vapor deposition layer / substrate film / first inorganic oxide vapor deposition layer / barrier coat layer"), an acid-modified polypolyolefin layer (maleic anhydride-modified polyethylene), and a sealant layer (polyethylene).

[0138] [Example 14] A barrier laminate was fabricated in the same manner as in Example 1, except that a silicon oxide vapor-deposited film was formed as the first inorganic oxide vapor-deposited layer to create a barrier film.

[0139] [Example 15] A barrier laminate was fabricated in the same manner as in Example 13, except that a silicon oxide vapor-deposited film was formed as the first inorganic oxide vapor-deposited layer to create a barrier film.

[0140] [Comparative Example 1] A barrier laminate was fabricated in the same manner as in Example 1, except that the ratio of solution A to solution B was 2.00 / 1 to create the barrier film.

[0141] [Comparative Example 2] A barrier laminate was fabricated in the same manner as in Example 1, except that the barrier film was made with a barrier coat layer thickness of 150 nm in the dry state.

[0142] <<Oxygen permeability measurement>> For the barrier laminates manufactured in the examples and comparative examples, an oxygen permeability measuring device (Modern Control (MOCON) Corporation [Model name: OX-TRAN 2 / 21]) was used, with the oxygen supply side facing the paper substrate layer of the barrier film. The measurement conditions were 23°C and a 90% RH atmosphere, and the oxygen permeability (cc / m³) was measured in accordance with JIS K7126-1:2006. 2 The following parameters (atm·day) were measured. The measurement results are shown in Table 2.

[0143] <<Adhesion strength rating A>> Test specimens of the barrier laminates manufactured in the examples and comparative examples were cut into 15 mm wide strips. Using a tensile testing machine (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.), the adhesion strength (N / 15 mm) between the barrier coat layer and the acid-modified polyolefin layer was measured in accordance with JIS Z1707:2019, using a 180° peel (T-peel method) at a peeling speed of 50 mm / min. Specifically, first, a strip-shaped test piece 50 was prepared by cutting out the barrier laminate and separating the barrier coat layer side 51 and the acid-modified polyolefin layer side 52 by 15 mm in the long-side direction, as shown in Figure 7. Then, as shown in Figure 8, the already separated portions of the barrier coat layer side 51 and the acid-modified polyolefin layer side 52 were gripped with the grips 53 of the measuring instrument. The grips 53 were each pulled at a speed of 50 mm / min in opposite directions perpendicular to the surface direction of the portion where the barrier coat layer side 51 and the acid-modified polyolefin layer side 52 were still laminated, and the average value of the tensile stress F in the stable region (see Figure 9) was measured. The distance S between the grips 53 at the start of pulling was 30 mm, and the distance S between the grips 53 at the end of pulling was 60 mm. Figure 9 shows the change in tensile stress F with respect to the distance S between the grips 53. As shown in Figure 9, the change in tensile stress F with respect to the interval S passes through the first region R1 and then enters the second region R2, where the rate of change is smaller than in the first region R1. The second region R2 is also called the stable region. For five test specimens (50 total), the average tensile stress F in the stable region R2 was measured, and this average value was defined as the laminate strength. The measurement environment for the laminate strength was 23°C and 50% relative humidity. The measurement results are shown in Table 2.

[0144] <<Adhesion strength rating: B>> The adhesion strength between the second inorganic oxide vapor-deposited layer and the olefin-unsaturated carboxylic acid copolymer layer in the barrier laminates produced in the examples and comparative examples was measured in the same manner as described above for adhesion strength A. In all barrier laminates of the examples and comparative examples, cohesive failure occurred within the layers before the second inorganic oxide vapor-deposited layer and the olefin-unsaturated carboxylic acid copolymer layer delaminated. Note that cohesive failure within the layers occurred in all cases when a tensile stress F of 15 N or more was applied.

[0145] [Table 2]

[0146] The barrier laminate according to the present invention has good gas barrier properties. The barrier laminate according to the present invention exhibits superior adhesion strength (adhesion strength A) between the barrier coat layer and the acid-modified polyolefin layer compared to the adhesion strength A of the comparative example barrier laminate. In the barrier laminate according to the present invention, cohesive failure occurs within the layers before the second inorganic oxide vapor deposition layer and the olefin-unsaturated carboxylic acid copolymer layer peel off, resulting in excellent adhesion between the barrier coat layer and the acid-modified polyolefin layer. [Explanation of Symbols]

[0147] 10: Barrier film 11: Base film 12: First inorganic oxide vapor deposition layer 13: Barrier Coat Layer 14: Second inorganic oxide vapor deposition layer 20: Barrier laminate 21:Paper base material 22: Barrier layer 23: Sealant layer 24: Acid-modified polyolefin layer 25: Olefin-unsaturated carboxylic acid copolymer layer 30: Paper container 31: Torso 32: Bottom 33: Top 34: Inclined plate 35: Folded section 36: Overlap 40: Packaging bag 50: Test specimen 51: Barrier coat layer side 52: Acid-modified polyolefin layer side 53: Gripping tool

Claims

1. A barrier laminate comprising a paper substrate layer, a barrier layer, and a sealant layer in this order, and comprising an acid-modified polyolefin layer between the paper substrate layer and the barrier layer, and between the barrier layer and the sealant layer, The barrier layer is a barrier film comprising a base film, a first inorganic oxide vapor deposition layer, and a barrier coating layer in this order. The barrier coating layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer. When the surface of the barrier coating layer is measured by X-ray photoelectron spectroscopy (XPS), the ratio of metal atoms (M) to carbon atoms (C) (M / C) is 0.80 or more and 1.35 or less. The thickness of the barrier coating layer is 155 nm or more and 300 nm or less. The acid-modified polyolefin layer is in contact with the barrier coat layer, forming a barrier laminate.

2. The barrier laminate according to claim 1, wherein the hardness of the barrier coating layer is 1.25 GPa or less.

3. The barrier laminate according to any one of claims 1 to 2, wherein the plastic deformation rate of the barrier coat layer is 35% or more.

4. The barrier laminate according to any one of claims 1 to 3, wherein the first inorganic oxide vapor deposition layer comprises an aluminum oxide vapor deposition film or a silicon oxide vapor deposition film.

5. The barrier film further comprises a second inorganic oxide deposition layer, The barrier laminate according to any one of claims 1 to 4, wherein the base film is located between the first inorganic oxide vapor deposition layer and the second inorganic oxide vapor deposition layer.

6. The barrier laminate according to claim 5, wherein the second inorganic oxide vapor deposition layer includes an aluminum oxide vapor deposition film or a silicon oxide vapor deposition film.

7. The acid-modified polyolefin layer is provided between the paper substrate layer and the barrier layer, and between the barrier layer and the sealant layer, and the olefin-unsaturated carboxylic acid copolymer layer is provided between the other, The acid-modified polyolefin layer is in contact with the barrier coat layer, The barrier laminate according to claim 5 or 6, wherein the olefin-unsaturated carboxylic acid copolymer layer is in contact with the second inorganic oxide deposition layer.

8. A packaging product comprising a barrier laminate according to any one of claims 1 to 7.

9. A method for manufacturing a barrier laminate, The barrier laminate comprises a paper substrate layer, a barrier layer, and a sealant layer in this order, and an acid-modified polyolefin layer is provided between the paper substrate layer and the barrier layer, and between the barrier layer and the sealant layer, The barrier layer is a barrier film comprising a base film, a first inorganic oxide vapor deposition layer, and a barrier coating layer in this order. The barrier coating layer is a cured film of a hydrolysis product of a metal alkoxide and a water-soluble polymer. When the surface of the barrier coating layer is measured by X-ray photoelectron spectroscopy (XPS), the ratio of metal atoms (M) to carbon atoms (C) (M / C) is 0.80 or more and 1.35 or less. The thickness of the barrier coating layer is 155 nm or more and 300 nm or less. The acid-modified polyolefin layer is in contact with the barrier coat layer, A method for manufacturing a barrier laminate, comprising the step of applying a barrier coating liquid containing a gas barrier composition onto the first inorganic oxide vapor deposition layer and heating and drying it at 130°C or higher and less than 200°C to form the barrier coating layer.

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