Manufacturing method of laminates

Abstract

The present invention provides a method for manufacturing a laminate that exhibits excellent gas barrier properties after bending. [Solution] The method for manufacturing the laminate includes the steps of preparing a paper substrate, forming a sealing layer on at least one side of the paper substrate by melt molding, and forming a gas barrier layer on one side of the sealing layer.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a laminate. [Background technology]

[0002] In recent years, laminates based on paper have been used from an environmental protection standpoint. For example, a paper laminate has been proposed that comprises a clay coat layer, an undercoat layer, a vapor-deposited layer, an overcoat layer, and a heat-seal layer in this order on at least one surface of a paper substrate (for example, Patent Document 1). In the paper laminate described in Patent Document 1, the clay coat layer is formed by coating an aqueous coating solution in which clay and a water-suspendable polymer are dispersed in an aqueous medium and then drying it. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-169426 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the laminate described in Patent Document 1 has the drawback of reduced gas barrier properties after bending.

[0005] This invention provides a method for manufacturing a laminate that exhibits excellent gas barrier properties after bending. [Means for solving the problem]

[0006] The present invention [1] is a method for manufacturing a laminate, comprising the steps of preparing a paper substrate, forming a sealing layer on at least one side of the paper substrate by melt molding, and forming a gas barrier layer on one side of the sealing layer.

[0007] The present invention [2] is a method for producing the laminate described in [1] above, wherein the sealing layer comprises at least one selected from the group consisting of polyurethane, polyolefin, acid-modified polyolefin, olefin-acrylic copolymer, and olefin-acrylic copolymer ionomer.

[0008] The present invention [3] is a paper substrate in which the amount is 180 g / m². 2 The method for manufacturing the laminate described in [1] or [2] above is as follows:

[0009] The present invention [4] relates to a laminate whose total amount is 200 g / m². 2 The following is a method for manufacturing a laminate described in any one of the above [1] to [3]. [Effects of the Invention]

[0010] According to the method for manufacturing a laminate of the present invention, it is possible to provide a laminate with excellent gas barrier properties after bending. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing Embodiment 1 of the laminate of the present invention. [Figure 2] This is a schematic cross-sectional view showing Embodiment 1 of the method for manufacturing a laminate according to the present invention. Figure 2A shows the step of preparing a paper substrate. Figure 2B shows the step of forming a sealing layer on one side of the paper substrate. Figure 2C shows the step of forming a gas barrier layer on one side of the sealing layer. Figure 2D shows the step of forming a heat seal layer on one side of the gas barrier layer. [Figure 3] This is a schematic cross-sectional view showing Embodiment 2 of the laminate of the present invention. [Figure 4] This is a schematic cross-sectional view showing Embodiment 2 of the method for manufacturing a laminate according to the present invention. Figure 4A shows the step of preparing a paper substrate. Figure 4B shows the step of forming a sealing layer on one side of the paper substrate. Figure 4C shows the step of forming a gas barrier layer on one side of the sealing layer. Figure 4D shows the step of forming a heat seal layer on one side of the gas barrier layer. [Modes for carrying out the invention]

[0012] <Embodiment 1> [Laminate] Referring to FIG. 1, the laminate 1 of Embodiment 1 includes a paper base material 10, a blocking layer 12, and a gas barrier layer 14 in this order. The product of the grammage (g / m 2 ) and the smoothness (seconds) in the blocking layer 12 is 4000 or more. The laminate 1 of Embodiment 1 is excellent in gas barrier properties after being bent. In the laminate 1 of Embodiment 1, as will be described later, the gas barrier layer 14 contains, for example, a gas barrier resin layer composition.

[0013] (1) Paper base material The paper base material 10 is a base material formed from paper. Examples of the paper base material 10 include paper made by papermaking pulp. Examples of the pulp include natural pulp and synthetic pulp. More specifically, examples of the paper base material 10 include glassine paper, coated paper, single-sided kraft paper, roll paper, and cup base paper. The paper base material 10 may be a single-layer paper or a multi-layer paper. The paper base material 10 is appropriately selected according to the use of the laminate 1.

[0014] The shape of the paper base material 10 is not particularly limited and is appropriately set. Examples of the shape of the paper base material 10 include sheet shape, bottle shape, and cup shape. Preferably, the shape of the paper base material 10 is sheet shape.

[0015] The paper base material 10 may be surface-treated as necessary. Examples of the surface treatment include corona treatment, surface coating treatment, and vapor deposition treatment.

[0016] The basis weight of the paper base material 10 is, for example, 20 g / m 2 or more, preferably 40 g / m 2 or more, more preferably 60 g / m 2 . Also, the basis weight of the paper base material 10 is, for example, 400 g / m 2 or less, preferably 250 g / m 2 or less, more preferably 200 g / m 2More preferably, 180 g / m² 2 More preferably, 140 g / m² 2 The following is particularly preferred: 120 g / m² 2 Below, most preferably 100 g / m 2 The following applies:

[0017] (2) Sealing layer The sealing layer 12 is positioned on one side of the paper substrate 10, preferably on one surface of the paper substrate 10. That is, the sealing layer 12 is in contact with the paper substrate 10. The sealing layer 12 absorbs surface irregularities of the paper substrate 10, smoothing the surface, and also suppresses the penetration of the gas barrier coating material (described later) into the paper substrate 10.

[0018] The sealing layer 12 is formed by melt-molding a molten coating material onto the surface of the paper substrate 10. The molten coating material contains a sealing resin. The molten coating material is prepared as a block (solid) sealing resin. Preferably, the molten coating material is prepared as a sealing resin in a predetermined shape (e.g., pellet shape). The molten coating material may contain additives. Examples of additives include thickening inhibitors, heat stabilizers, antioxidants, light stabilizers, UV absorbers, plasticizers, antistatic agents, lubricants, antiblocking agents, pigments, dyes, nucleating agents, and curing agents. These can be used individually or in combination of two or more types.

[0019] [Sealing resin] The sealing resin comprises at least one selected from the group consisting of polyurethane, polyolefin, acid-modified polyolefin, and olefin-(meth)acrylic acid copolymer. Because the sealing resin comprises at least one of the above, it is thermoplastic and can be melt-molded. In other words, the sealing resin is a thermoplastic resin.

[0020] The sealing resin, from the viewpoint of maintaining high gas barrier properties of the laminate 1 after bending, comprises at least one selected from the group consisting of polyurethane, polyolefin, acid-modified polyolefin, olefin-(meth)acrylic acid copolymer, and olefin-(meth)acrylic acid copolymer ionomer, preferably comprising at least one selected from the group consisting of polyolefin, acid-modified polyolefin, and olefin-(meth)acrylic acid copolymer, more preferably comprising at least one selected from the group consisting of acid-modified polyolefin and olefin-(meth)acrylic acid copolymer, and even more preferably comprising olefin-(meth)acrylic acid copolymer.

[0021] (Polyurethane) Examples of polyurethanes include thermoplastic polyurethanes. Examples of thermoplastic polyurethanes include reaction products of a pore-sealing polyisocyanate component and a pore-sealing active hydrogen group-containing component.

[0022] Examples of polyisocyanate components for sealing include industrially common polyisocyanates. More specifically, examples of polyisocyanate components for sealing include linear aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and aromatic aliphatic polyisocyanates.

[0023] Examples of linear aliphatic polyisocyanates include pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), and their derivatives. Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and 4,4'-methylenebis(cyclohexyl isocyanate) (H 12Examples of polyisocyanates include MDI, bis(isocyanatomethyl)cyclohexane (H6XDI), and their derivatives. Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and their derivatives. Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), and their derivatives.

[0024] Examples of derivatives include polymers, isocyanurate-modified derivatives, allophanate-modified derivatives, polyol-modified derivatives, biuret-modified derivatives, urea-modified derivatives, oxadiazinetrione-modified derivatives, and carbodiimide-modified derivatives. These can be used individually or in combination of two or more types.

[0025] Preferably, the polyisocyanate component for sealing is an alicyclic polyisocyanate, and more preferably, bis(isocyanatomethyl)cyclohexane (H6XDI). Examples of bis(isocyanatomethyl)cyclohexane include 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane, and preferably, 1,4-bis(isocyanatomethyl)cyclohexane.

[0026] Examples of active hydrogen group-containing components for sealing include polyols. Examples of polyols include high molecular weight polyols and low molecular weight polyols.

[0027] High molecular weight polyols are, for example, polyols with a number average molecular weight of 400 to 20,000. Examples of high molecular weight polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols.

[0028] Low molecular weight polyols are, for example, polyols with a number average molecular weight of 40 or more and less than 400 (preferably less than 300). Examples of low molecular weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. These can be used individually or in combination of two or more.

[0029] Thermoplastic polyurethanes are obtained by reacting a pore-sealing polyisocyanate component with a pore-sealing active hydrogen group-containing component using a known method. The reaction method between the pore-sealing polyisocyanate component and the pore-sealing active hydrogen group-containing component is not particularly limited and includes, for example, a one-shot method and a prepolymer method. The pore-sealing polyisocyanate component and the pore-sealing active hydrogen group-containing component may be reacted in the presence of a known reaction solvent, if necessary. Furthermore, a known urethane catalyst may be added to the reaction between the pore-sealing polyisocyanate component and the pore-sealing active hydrogen group-containing component, if necessary.

[0030] (Polyolefin) Examples of polyolefins include polymers of olefins having 2 to 20 carbon atoms.

[0031] Examples of olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene, with ethylene and / or propylene being preferred.

[0032] Polyolefins include polyethylene and / or polypropylene. Polyethylenes include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and ultra-low-density polyethylene, with low-density polyethylene being preferred. Low-density polyethylenes include linear low-density polyethylene. Polypropylenes include three types based on differences in stereoregularity: isotactic, syndiotactic, and atactic (random), with atactic (random) polypropylene being preferred.

[0033] Polymers of olefins having 2 to 20 carbon atoms can be obtained by polymerizing olefins having 2 to 20 carbon atoms using known methods. For example, the polymerization method involves polymerizing α-olefins having 2 to 20 carbon atoms in the presence of a metallocene catalyst.

[0034] (Acid-modified polyolefin) Acid-modified polyolefins can be obtained, for example, by modifying the above-mentioned polyolefins with an acidic component. The acidic component may have, for example, a carboxyl group or an acid anhydride group.

[0035] Preferably, the acid component is an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, and citraconic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, and tetrahydrophthalic anhydride, with maleic anhydride being preferred.

[0036] The modification of an acid-modified polyolefin with an acid component is carried out, for example, by first dissolving the polyolefin in a known organic solvent (e.g., toluene). Then, a known radical generator is added, and the mixture is heated and stirred.

[0037] The heating temperature is, for example, 50°C to 250°C, preferably 80°C to 200°C, and more preferably 120°C to 190°C. The reaction time is, for example, 1 minute to 10 hours.

[0038] As a result, the acid component undergoes graft polymerization on the above-mentioned polyolefin, yielding an acid-modified polyolefin. The content of constituent units derived from the acid component is 0.2% to 1.2% by mass, preferably 0.3% to 1.1% by mass, more preferably 0.4% to 1.0% by mass, and even more preferably 0.5% to 0.9% by mass, relative to the acid-modified polyolefin.

[0039] (Olefin-(meth)acrylic acid copolymer) Olefin-(meth)acrylic acid copolymers are obtained by copolymerization of polymer components containing olefin and (meth)acrylic acid.

[0040] In the polymerization component, the blending ratio of olefin is, for example, 60 parts by mass or more, preferably 75 parts by mass or more, and for example, 95 parts by mass or less, preferably 92 parts by mass or less, with respect to 100 parts by mass of the total amount of olefin and (meth)acrylic acid. Also, the blending ratio of (meth)acrylic acid is, for example, 5 parts by mass or more, preferably 8 parts by mass or more, and for example, 40 parts by mass or less, preferably 25 parts by mass or less, with respect to 100 parts by mass of the total amount of olefin and (meth)acrylic acid.

[0041] The proportion of olefin and (meth)acrylic acid relative to the polymerization component is, for example, 60% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more.

[0042] Olefin-(meth)acrylic acid copolymers are obtained by copolymerizing polymerization components in a predetermined ratio using a known polymerization method.

[0043] Examples of olefin-(meth)acrylic acid copolymers include copolymers of an olefin having 2 to 20 carbon atoms and (meth)acrylic acid, preferably copolymers of the above-mentioned olefin having 2 or 3 carbon atoms and (meth)acrylic acid, and more preferably copolymers of ethylene and (meth)acrylic acid. The olefin-(meth)acrylic acid copolymer has a carboxyl group derived from (meth)acrylic acid.

[0044] The acid content in the olefin-(meth)acrylic acid copolymer is, for example, 2% by mass or more, preferably 5% by mass or more, and, for example, 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less. The acid content is calculated as the ratio of (meth)acrylic acid to the total amount of olefin and (meth)acrylic acid in the polymerization components.

[0045] (Olefin-(meth)acrylic acid copolymer ionomer) Olefin-(meth)acrylic acid copolymer ionomers are obtained by neutralizing the carboxyl groups of the above-mentioned olefin-(meth)acrylic acid copolymer with a monovalent metal and / or a divalent metal.

[0046] Examples of monovalent metals include sodium and potassium, with sodium being preferred from the viewpoint of ease of manufacture. Examples of divalent metals include magnesium, zinc, calcium, copper, iron, and barium, with zinc being preferred from the viewpoint of ease of manufacture.

[0047] To neutralize the carboxyl groups of the olefin-(meth)acrylic acid copolymer with a monovalent metal and / or a divalent metal, the olefin-(meth)acrylic acid copolymer is mixed with a compound containing a monovalent metal and / or a compound containing a divalent metal.

[0048] Examples of compounds containing a monovalent metal include the hydroxide of the monovalent metal, preferably sodium hydroxide. Examples of compounds containing a divalent metal include the oxide, hydroxide, and carbide of the divalent metal, preferably the hydroxide of the divalent metal, and more preferably zinc hydroxide.

[0049] The metal that neutralizes the ionomer resin comprises a monovalent metal and / or a divalent metal, preferably comprising a monovalent metal or a divalent metal, and more preferably comprising only a monovalent metal or only a divalent metal.

[0050] Such ionomers neutralized with a monovalent metal and / or a divalent metal are preferably, from the viewpoint of adhesion, ionomers neutralized with a monovalent metal or ionomers neutralized with a divalent metal, more preferably ionomers neutralized with sodium or ionomers neutralized with zinc.

[0051] (Melting point of sealing resin) From the viewpoint of melt molding under suitable conditions, the melting point of the sealing resin is, for example, 60°C or higher, preferably 80°C or higher, more preferably 90°C or higher, and also, for example, 300°C or lower, preferably 250°C or lower, more preferably 225°C or lower, and even more preferably 200°C or lower.

[0052] (Meltmass flow rate of sealing resin) The melt mass flow rate (MFR) of the sealing resin is, from the viewpoint of melt molding under suitable conditions, for example, 0.5 g / 10 min or more, preferably 1.0 g / 10 min or more, more preferably 2.0 g / 10 min or more, and even more preferably 4.0 g / 10 min or more, and also, for example, 30 g / 10 min or less, preferably 25 g / 10 min or less, more preferably 15 g / 10 min or less, and even more preferably 10 g / 10 min or less. The MFR of the sealing resin is measured in accordance with JIS K7210-1:2014.

[0053] [Weighing of sealing layer] The weight of the sealing layer 12 is, for example, 1.5 g / m². 2 The above is preferable, preferably 3.0 g / m 2 That is all, and also, for example, 30.0 g / m 2 The following, preferably 20.0 g / m² 2 The following applies:

[0054] If the sealing layer 12 contains an acid-modified polyolefin, the weight of the sealing layer is, for example, 1.5 g / m². 2 The above is preferable, preferably 3.0 g / m 2 The above is preferable, and more preferably 10.0 g / m 2 The above, and more preferably 17.5 / m 2 That is all, and also, for example, 30.0 g / m 2 The following, preferably 20.0 g / m² 2 The following applies:

[0055] If the sealing layer 12 contains an olefin-(meth)acrylic acid copolymer, the weight of the sealing layer is, for example, 1.5 g / m². 2 The above is preferable, preferably 3.0 g / m 2 That is all, and also, for example, 30.0 g / m 2 The following, preferably 20.0 g / m² 2 The following, and more preferably 15.0 g / m² 2 The following, and more preferably 10 g / m² 2 The following is particularly preferred: 6 g / m 2 The following applies:

[0056] [Smoothness of the sealing layer] The smoothness of the sealing layer refers to the smoothness of one surface of the sealing layer (the surface facing the gas barrier layer). It is evaluated by measuring the time (s) required for a certain amount of atmospheric pressure air to flow between a test specimen (one surface of the sealing layer) and a ring-shaped plane, under specific initial differential pressure conditions. A larger time (s) indicates higher smoothness. The smoothness of the sealing layer is measured in accordance with JIS P8155:2010.

[0057] The smoothness of the sealing layer 12 is, for example, 400 seconds or more, preferably 450 seconds or more, more preferably 500 seconds or more, and also, for example, 1500 seconds or less, preferably 1100 seconds or less.

[0058] [The product of weight and smoothness in the sealing layer] A product of the weight and smoothness of the sealing layer being 4000 or more ensures high gas barrier properties after bending. In other words, the greater the weight of the sealing layer and the higher the smoothness of the sealing layer, the higher the gas barrier properties after bending.

[0059] The product of the weight and smoothness in the sealing layer is 4000 or more, preferably 5000 or more, from the viewpoint of maintaining high gas barrier properties after bending, and, from the viewpoint of manufacturing the laminate, for example, 17000 or less, preferably 10000 or less.

[0060] If the sealing layer 12 contains an acid-modified polyolefin, the product of the weighing and smoothness in the sealing layer is 4000 or more, preferably 5000 or more, more preferably 9000 or more, even more preferably 10000 or more, and also, for example, 17000 or less.

[0061] If the sealing layer 12 contains an olefin-(meth)acrylic acid copolymer, the product of the weighing and smoothness in the sealing layer is 4000 or more, and for example, 17000 or less, preferably 12000 or less, more preferably 7000 or less, more preferably 6000 or less, and even more preferably 5000 or less.

[0062] (3) Gas barrier layer The gas barrier layer 14 is positioned on one side of the sealing layer 12, preferably on one surface of the sealing layer 12. That is, the gas barrier layer 14 is preferably in contact with the sealing layer 12. The gas barrier layer 14 is a layer having gas barrier properties and ensures the gas barrier properties of the laminate 1.

[0063] The gas barrier property of the gas barrier layer 14 refers to its property of reducing oxygen permeability. More specifically, the gas barrier layer 14 is made of a gas barrier resin composition having an oxygen permeability of a predetermined value or less. For example, weighing capacity of 10 g / m² 2 The oxygen permeability of the gas barrier layer 14 is, for example, 1 (cc / (m³) at room temperature. 2 The value is less than or equal to (day·atm). Oxygen permeability is measured in accordance with Method B of JIS K7126:2006, using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 22H). Measurement conditions are 20°C and 80%RH (relative humidity).

[0064] The gas barrier layer 14 is formed by applying and drying a gas barrier coating material to the surface of the sealing layer 12. The gas barrier coating material includes a gas barrier resin composition. The gas barrier coating material may contain the additives described above.

[0065] [Gas barrier resin composition] A gas barrier resin composition includes, for example, a resin and a layered inorganic compound dispersed in the resin.

[0066] (resin) Examples of resins include polyurethane resins, acrylic resins, polyolefin resins, and polyvinyl alcohol resins, with polyurethane resins and polyvinyl alcohol resins being preferred, and polyurethane resins being more preferred. In particular, from the viewpoint of improving the overall gas barrier properties (gas barrier properties against oxygen and water vapor) of the gas barrier layer, polyurethane resins are preferred, and gas barrier polyurethane resins are even more preferred.

[0067] Polyvinyl alcohol resin has lower oxygen permeability before and after bending compared to polyurethane resin, but higher water vapor permeability before bending. In other words, polyurethane resin has higher gas barrier properties against both oxygen and water vapor compared to polyvinyl alcohol resin.

[0068] The gas barrier polyurethane resin contains, for example, a reaction product of an isocyanate group-terminated prepolymer and a chain extender, and preferably consists of a reaction product of an isocyanate group-terminated prepolymer and a chain extender. The isocyanate group-terminated prepolymer contains, for example, a reaction product of a gas barrier polyisocyanate component and a gas barrier active hydrogen group-containing component, and preferably consists of a reaction product of a gas barrier polyisocyanate component and a gas barrier active hydrogen group-containing component.

[0069] Examples of polyisocyanate components for gas barriers include known polyisocyanate components. From the viewpoint of gas barrier properties, the polyisocyanate component preferably contains xylylene diisocyanate (XDI) and / or bis(isocyanatomethyl)cyclohexane (H6XDI). In addition, the polyisocyanate component may optionally contain other polyisocyanates (polyisocyanates other than xylylene diisocyanate and bis(isocyanatomethyl)cyclohexane).

[0070] The polyisocyanate component for gas barriers preferably contains xylylene diisocyanate (XDI) and / or bis(isocyanatomethyl)cyclohexane (H6XDI) and other polyisocyanates (preferably methylenebis(cyclohexyl isocyanate)). The proportions of these components are set appropriately depending on the purpose and application.

[0071] The active hydrogen group-containing component for gas barriers is an organic compound containing an active hydrogen group. Examples of active hydrogen groups include hydroxyl groups and amino groups, with hydroxyl groups being preferred. Examples of active hydrogen group-containing components for gas barriers include known active hydrogen group-containing compounds. From the viewpoint of gas barrier properties, the active hydrogen group-containing component for gas barriers preferably contains an active hydrogen group-containing compound that contains a short-chain diol having 2 to 6 carbon atoms and an anionic group.

[0072] Short-chain diols having 2 to 6 carbon atoms are organic compounds having 2 to 6 carbon atoms and possessing two hydroxyl groups in one molecule. Examples of short-chain diols include alkanediols having 2 to 6 carbon atoms and etherdiols having 2 to 6 carbon atoms, preferably alkanediols having 2 to 6 carbon atoms, and more preferably ethylene glycol.

[0073] Furthermore, active hydrogen group-containing compounds for gas barriers may also contain triols. Examples of triols include trimethylolpropane.

[0074] Preferably, organic compounds containing anionic groups and active hydrogen groups include organic compounds having one carboxyl group and two or more hydroxyl groups in one molecule, and more preferably, organic compounds having one carboxyl group and two hydroxyl groups in one molecule. Preferably, organic compounds having one carboxyl group and two hydroxyl groups include polyhydroxyalkanoic acid, and even more preferably, 2,2-dimethylolpropionic acid.

[0075] The isocyanate-terminated prepolymer is obtained by reacting the above components in a predetermined equivalence ratio using a known polymerization method. The equivalence ratio (isocyanate group / active hydrogen group) is, for example, 1.1 or more and 10 or less. Preferably, a known neutralizing agent is added to neutralize the carboxyl group.

[0076] Chain elongators are organic compounds that cause chain elongation reactions in isocyanate-terminated prepolymers. Chain elongators have multiple active hydrogen groups. Examples of chain elongators include polyamines, amino group-containing alkoxysilyl compounds, and amino alcohols (e.g., 2-(2-aminoethylamino)ethanol, diethanolamine (DEA)), and diamines (e.g., ethylenediamine (EDA)).

[0077] To react the isocyanate-terminated prepolymer with the chain extender, for example, first, the isocyanate-terminated prepolymer is dispersed in water by adding it to water, and then the chain extender is added to extend the chains of the isocyanate-terminated prepolymer. The equivalent ratio of the chain extender to the isocyanate-terminated prepolymer (active hydrogen group / isocyanate group) is, for example, 0.6 to 1.2. This yields a gas barrier polyurethane resin, and a dispersion (polyurethane dispersion) is prepared in which the gas barrier polyurethane resin is dispersed in water.

[0078] (Layered inorganic compounds) Examples of layered inorganic compounds include swellable layered inorganic compounds and non-swellable layered inorganic compounds. From the viewpoint of gas barrier properties, swellable layered inorganic compounds are preferred.

[0079] Swellable layered inorganic compounds are clay minerals consisting of extremely thin unit crystals, in which solvents coordinate or absorb and swell between the unit crystal layers.

[0080] Examples of swellable layered inorganic compounds include, for example, hydrated silicates (phyllosilicate minerals, etc.), kaolinite clay minerals (haloysite, kaolinite, endelite, dickite, nacrite, etc.), antigorite clay minerals (antigorite, chrysotile, etc.), smectite clay minerals (montmorillonite, bydelite, nontronite, saponite, hectorite, souconite, stevensite, etc.), vermiculite clay minerals (vermiculite, etc.), mica or mica clay minerals (muscovite, phlogopite, etc., margalite, tetrasilicic mica, teniolite, etc.), and synthetic mica.

[0081] These swellable layered inorganic compounds may be natural clay minerals or synthetic clay minerals. They can be used alone or in combination of two or more. Preferably, examples include smectite group clay minerals (such as montmorillonite), mica group clay minerals (such as water-swellable mica), and synthetic mica, with synthetic mica being more preferred.

[0082] Then, a layered inorganic compound is blended with the above-mentioned gas barrier polyurethane resin to obtain a gas barrier resin composition. Specifically, a layered inorganic compound is blended with the above-mentioned polyurethane dispersion to prepare a gas barrier coating material.

[0083] (Mass ratio of resin to layered inorganic compound in gas barrier resin composition) The proportion of resin in the gas barrier resin composition is, from the viewpoint of maintaining high gas barrier properties of the gas barrier layer, for example, 35 parts by mass or more, preferably 45 parts by mass or more, more preferably 55 parts by mass or more, and also, for example, 95 parts by mass or less, preferably 85 parts by mass or less, and more preferably 80 parts by mass or less, per 100 parts by mass of the gas barrier resin composition (solids). The proportion of layered inorganic compound in the gas barrier resin composition is, from the viewpoint of maintaining high gas barrier properties of the gas barrier layer, for example, 5 parts by mass or more, preferably 15 parts by mass or more, more preferably 20 parts by mass or more, per 100 parts by mass of the gas barrier resin composition (solids), and also, for example, 65 parts by mass or less, preferably 55 parts by mass or less, and more preferably 45 parts by mass or less.

[0084] [Weighing of gas barrier layer] The weight of the gas barrier layer 14 is, for example, 0.2 g / m². 2 Preferably 0.5 g / m 2 Above all, a comfortable 1.0 g / m 2 That's all, and also, for example, 10g / m 2 Preferably 7.0 g / m 2 More preferably, 5.0 g / m 2 The following applies:

[0085] (4) Heat seal layer The laminate 1 may further include a heat seal layer 16. The heat seal layer 16 is located on one side of the gas barrier layer 14, preferably on one surface of the gas barrier layer 14. That is, the heat seal layer 16 is preferably in contact with the gas barrier layer 14. The heat seal layer 16 is a heat-sealable layer and ensures the heat sealability of the laminate 1. Furthermore, the presence of the heat seal layer 16 improves the gas barrier properties of the laminate 1 after bending.

[0086] The heat seal layer 16 is formed by applying and drying a heat sealable coating material on the surface of the gas barrier layer 14. The heat sealable coating material includes a heat sealable resin.

[0087] [Heat-sealable resin] A heat-sealable resin is a resin that can be heat-sealed (heat-fused) to one another. The heat-sealable resin is not particularly limited, and known heat-sealable resins can be used. More specifically, examples of heat-sealable resins include polyolefins, (meth)acrylic resins (including ethylene-(meth)acrylic acid copolymers and ethylene-(meth)acrylate alkyl ester-(meth)acrylic acid copolymers), and the polyurethanes mentioned above. These can be used individually or in combination of two or more types.

[0088] Heat-sealable coating materials are prepared as an organic solvent solution of a heat-sealable resin or as an aqueous dispersion of a heat-sealable resin. For example, to prepare an aqueous dispersion, in the case of acrylic resins, an olefin-(meth)acrylic acid copolymer or an olefin-(meth)acrylate alkyl ester-(meth)acrylic acid copolymer is dispersed in water. Alternatively, a carboxylic acid-modified acrylic resin can be prepared by copolymerizing (meth)acrylic acid with an (meth)acrylate alkyl ester, and then dispersed in water. Furthermore, two or more resins selected from acrylic resins can be melt-kneaded and then dispersed in water. Specifically, olefin-(meth)acrylic acid copolymers and olefin-(meth)acrylate alkyl ester-(meth)acrylic acid copolymers can be melt-kneaded and then dispersed in water.

[0089] Furthermore, the heat-sealable coating material may contain the additives described above. Furthermore, the heat seal layer can also be formed by laminating the polyolefin film described above onto the gas barrier layer 14 via a known adhesive.

[0090] [Weighing of heat-sealed layers] The weight of the heat seal layer 16 is, for example, 0.5 g / m². 2 Preferably 1.0 g / m 2 More preferably 2.0 g / m 2 The above is preferable, and more preferably 5.0 g / m 2 That's all, and also, for example, 20g / m 2 Preferably 10 g / m 2 The following applies:

[0091] [Basis weight of laminated material] The basis weight of laminate 1 is, for example, 25 g / m², from the viewpoint of gas barrier properties. 2 Preferably 45 g / m² 2 More than 65g / m 2 That concludes the explanation. Furthermore, the basis weight of laminate 1 should be, for example, 435 g / m², from the viewpoint of heat sealability. 2 Preferably 285 g / m² 2 More preferably 235 g / m²2 More preferably 200 g / m 2 More preferably, 180 g / m² 2 The following is particularly preferred: 160 g / m² 2 The following is most preferably 120 g / m² 2 The following applies.

[0092] [Method for manufacturing laminates] Referring to Figure 2, the manufacturing method of the laminate 1 of Embodiment 1 includes the steps of preparing a paper substrate 10 (Figure 2A), forming a sealing layer 12 on one side of the paper substrate 10 by melt molding (Figure 2B), forming a gas barrier layer 14 on one side of the sealing layer 12 (Figure 2C), and further including the step of forming a heat seal layer 16 on one side of the gas barrier layer 14 (Figure 2D). The manufacturing method of the laminate of Embodiment 1 can produce a laminate 1 with excellent gas barrier properties after bending.

[0093] (Process of preparing paper substrate) As shown in Figure 2A, prepare the paper substrate 10.

[0094] (Process of forming a sealing layer by melt molding) As shown in Figure 2B, a sealing layer 12 is formed on one side of the paper substrate 10 by melt molding. Preferably, the sealing layer 12 is formed on one surface of the paper substrate 10 by melt molding. By forming the sealing layer 12 by melt molding, the weighing capacity (g / m²) is reduced. 2 A sealing layer 12 can be obtained in which the product of () and the smoothness (seconds) is 4000 or more.

[0095] The melt molding method is not particularly limited as long as it can be used to melt and mold a thermoplastic resin. Examples include extrusion molding, injection molding, insert molding, blow molding, compression molding, and transfer molding, with extrusion molding being preferred. The extrusion method in extrusion molding is not particularly limited, and examples include unscrew extrusion and twin-screw extrusion. Specifically, an extrusion laminator equipped with an unscrew extruder and dies is used to extrude a molten coating material onto the surface of a paper substrate 10, thereby forming a sealing layer 12 on the surface of the paper substrate 10, thereby performing extrusion coating.

[0096] The following conditions can be cited as requirements for the extrusion coating process. • Die-under resin temperature: Above the melting point of the sealing resin, for example, 150°C or higher, preferably 200°C or higher, more preferably 250°C or higher, even more preferably 300°C or higher, and also, for example, 350°C or lower, preferably 320°C or lower.

[0097] If the resin temperature under the die is above the lower limit, excellent adhesive strength, as well as excellent ductility and high-speed processing capabilities, can be obtained. Furthermore, if the resin temperature under the die is below the upper limit, resin degradation can be suppressed, and the generation of gel, smoke, and odor can also be suppressed.

[0098] In extrusion coating processes, preferably, in order to improve the adhesive strength between the molten coating material and the paper substrate, the surface of the molten coating material that comes into contact with the paper substrate is treated with ozone, and the surface of the paper substrate that comes into contact with the molten coating material is treated with corona.

[0099] (Process for forming a gas barrier layer) As shown in Figure 2C, a gas barrier layer 14 is formed on one side of the sealing layer 12. Preferably, the gas barrier layer 14 is formed on one surface of the sealing layer 12.

[0100] There are no particular restrictions on the method for forming the gas barrier layer 14, but from the viewpoint of forming the gas barrier layer 14 simply and efficiently, it is formed by applying and drying a gas barrier coating material on one surface of the sealing layer 12.

[0101] The method of applying the gas barrier coating agent is not particularly limited, and known coating methods such as gravure coating, reverse coating, roll coating, bar coating, spray coating, air knife coating, and dipping can be used. It can also be applied in-line following the formation of the sealing layer 12.

[0102] Furthermore, the drying conditions include a drying temperature of, for example, 40°C or higher, preferably 50°C or higher, more preferably 90°C or higher, and for example, 200°C or lower, preferably 180°C or lower, and more preferably 150°C or lower. The drying time is, for example, 0.1 minutes or more, preferably 0.2 minutes or more, and for example, 10 minutes or less, preferably 5 minutes or less.

[0103] This allows a gas barrier layer 14 to be formed on the surface of the sealing layer 12.

[0104] (Process for forming a heat seal layer) As shown in Figure 2D, a heat seal layer 16 is formed on one side of the gas barrier layer 14. Preferably, the heat seal layer 16 is formed on one surface of the gas barrier layer 14.

[0105] There are no particular restrictions on the method for forming the heat seal layer 16, but from the viewpoint of forming a heat seal simply and efficiently, it is formed by applying and drying a heat sealable coating material containing a heat sealable resin on one surface of the gas barrier layer 14.

[0106] The method of applying the heat-sealable coating agent is not particularly limited and includes known coating methods such as gravure coating, reverse coating, roll coating, bar coating, spray coating, air knife coating, and dipping. It can also be applied in-line following the formation of the gas barrier layer.

[0107] Furthermore, the drying conditions include a drying temperature of, for example, 40°C or higher, preferably 50°C or higher, more preferably 90°C or higher, and for example, 200°C or lower, preferably 180°C or lower, and more preferably 150°C or lower. The drying time is, for example, 0.1 minutes or more, preferably 0.2 minutes or more, and for example, 10 minutes or less, preferably 5 minutes or less.

[0108] This allows a heat seal layer 16 to be formed on the surface of the gas barrier layer 14.

[0109] This yields laminate 1. Laminate 1 comprises a paper substrate 10, a sealing layer 12, and a gas barrier layer 14 in this order. Laminate 1 also has a weighing capacity (g / m²) in the sealing layer 12. 2 Since the product of () and smoothness (seconds) is 4000 or more, it exhibits excellent gas barrier properties after bending.

[0110] In the manufacturing method of the laminate according to Embodiment 1 of the present invention, a sealing layer 12, a gas barrier layer 14, and a heat seal layer 16 are sequentially formed on one side of the paper substrate 10. For example, when a vapor deposition layer is formed on the surface of a resin substrate and then laminated onto a paper substrate via an adhesive, the number of layers increases, resulting in a thicker laminate. However, compared to such a laminate, the laminate according to Embodiment 1 of the present invention can be made thinner.

[0111] In particular, in the manufacturing method of the laminate according to Embodiment 1 of the present invention, the sealing layer 12 is formed by melt molding, so the surface of the sealing layer 12 can be made smooth, and moreover, if the sealing layer 12 is formed by melt molding, the weighing capacity (g / m²) can be reduced. 2 Since a sealing layer 12 can be formed in which the product of () and the smoothness (seconds) is 4000 or more, a laminate with low oxygen permeability after bending and high gas barrier properties after bending can be obtained.

[0112] <Embodiment 2> In Embodiment 2 of the present invention, the same reference numerals are used for the same components and processes as in Embodiment 1, and their descriptions are omitted.

[0113] [Laminated structure] Referring to Figure 3, the laminate 1 of Embodiment 2 comprises a paper substrate 10, a sealing layer 12, and a gas barrier layer 14 in this order, and the weighing capacity (g / m²) of the sealing layer 12. 2 The product of the width and smoothness (seconds) is 4000 or more. The laminate 1 of Embodiment 2 has excellent gas barrier properties after bending. In the laminate 1 of Embodiment 2, as described later, the gas barrier layer 14 comprises an inorganic vapor deposition layer 145, preferably an undercoat layer 140 and an inorganic vapor deposition layer 145.

[0114] (1)Paper base material The paper substrate 10 in Embodiment 2 is the same as the paper substrate 10 in Embodiment 1.

[0115] (2) Sealing layer The sealing layer 12 of Embodiment 2 is the same as the sealing layer 12 of Embodiment 1, except for the following points.

[0116] If the sealing layer 12 contains an acid-modified polyolefin, the weight of the sealing layer is, for example, 1.5 g / m². 2 The above is preferable, preferably 3.0 g / m 2 The above is preferable, and more preferably 10.0 g / m 2 That is all, and also, for example, 30.0 g / m 2 The following, preferably 20.0 g / m² 2 The following applies:

[0117] If the sealing layer 12 contains an olefin-(meth)acrylic acid copolymer, the weight of the sealing layer is, for example, 1.5 g / m². 2 The above is preferable, preferably 3.0 g / m 2 The above is more preferable, or 5.0 g / m². 2 The above is preferable, and more preferably 7.5 g / m 2 That is all, and also, for example, 30.0 g / m 2 The following, preferably 20.0 g / m² 2 The following, and more preferably 15.0 g / m² 2 The following applies:

[0118] If the sealing layer 12 contains an acid-modified polyolefin, the product of the weighing and smoothness in the sealing layer is 4000 or more, preferably 5000 or more, more preferably 7500 or more, and also, for example, 17000 or less, preferably 12000 or less.

[0119] If the sealing layer 12 contains an olefin-(meth)acrylic acid copolymer, the product of the weighing and smoothness in the sealing layer is 4000 or more, preferably 5000 or more, more preferably 5500 or more, and also, for example, 17000 or less, preferably 10000 or less.

[0120] (3) Gas barrier layer The gas barrier layer 14 of Embodiment 2 includes an inorganic vapor deposition layer 145, preferably including an anchor coat layer 140 and an inorganic vapor deposition layer 145. When the gas barrier layer 14 includes an anchor coat layer 140 and an inorganic vapor deposition layer 145, the anchor coat layer 140 is located on one side of the sealing layer 12, preferably on one surface of the sealing layer 12, and the inorganic vapor deposition layer 145 is located on one side of the anchor coat layer 140, preferably on one surface of the anchor coat layer 140.

[0121] (Anchor coat layer) Preferably, the anchor coat layer 140 is formed between the sealing layer 12 and the inorganic vapor deposition layer 145 to improve adhesion between the sealing layer 12 and the inorganic vapor deposition layer 145. The anchor coat layer 140 is in contact with both the sealing layer 12 and the inorganic vapor deposition layer 145.

[0122] In this case, one side of the anchor coat layer 140 is in contact with the other side of the inorganic vapor deposition surface 145. One side of the sealing layer 12 is in contact with the other side of the anchor coat layer 140. If the heat seal layer 16 described later is formed, one side of the inorganic vapor deposition layer 145 is in contact with the other side of the heat seal layer 16.

[0123] Furthermore, if adhesion between the sealing layer 12 and the inorganic vapor deposition layer 145 can be ensured, the anchor coat layer 140 can be omitted.

[0124] The anchor coat layer 140 is formed by applying and drying the anchor coat material on the surface of the sealing layer 12. The anchor coat material includes an anchor coat resin.

[0125] Examples of anchor coating resins include polyurethane resins, acrylic resins, polyolefin resins, and polyvinyl alcohol resins, with polyurethane resins being preferred. Among polyurethane resins, gas barrier polyurethane resins are preferred.

[0126] The weighing of the anchor coat layer 140 is, for example, 0.2 g / m². 2 Preferably 0.5 g / m 2 Above all, a comfortable 1.0 g / m 2 That's all, and also, for example, 10g / m 2 Preferably 7.0 g / m 2 More preferably, 5.0 g / m 2 The following applies:

[0127] (Inorganic vapor deposited layer) Examples of inorganic materials (including metals) used in the inorganic vapor deposition layer 145 include magnesium, calcium, and barium from group 2 of the periodic table; titanium and zirconium from group 4; aluminum and indium from group 13; and silicon, germanium, and tin from group 14. Specifically, examples of inorganic materials include aluminum (Al), aluminum oxide (AlxOy), magnesium oxide (MgOx), titanium oxide (TiOx), indium oxide (InxOy), silicon oxide (SiOx), silicon oxide and nitride (SiOxNy), cerium oxide (CeOx), calcium oxide (CaOx), tin oxide (SnOx), diamond-like carbon film, or mixtures thereof. Among these, aluminum, silicon, and their oxides are preferred from the viewpoint of excellent gas barrier properties, and aluminum and its oxides are more preferred. Furthermore, the inorganic vapor deposition layer may be formed in multiple layers by combining multiple layers.

[0128] The thickness of the inorganic vapor deposition layer is, for example, 5 nm or more, preferably 20 nm or more, more preferably 50 nm or more, and also, for example, 250 nm or less, preferably 150 nm or less, more preferably 100 nm or less.

[0129] (4) Heat seal layer The heat seal layer 16 of Embodiment 2 is the same as the heat seal layer 16 of Embodiment 1.

[0130] [Method for manufacturing laminates] Referring to Figure 4, the manufacturing method of the laminate 1 of Embodiment 2 includes the steps of preparing a paper substrate 10 (Figure 4A), forming a sealing layer 12 on one side of the paper substrate 10 by melt molding (Figure 4B), forming a gas barrier layer 14 on one side of the sealing layer 12 (Figure 4C), and further including the step of forming a heat seal layer 16 on one side of the gas barrier layer 14. Furthermore, the manufacturing method of the laminate 1 of Embodiment 2 preferably includes the steps of preparing a paper substrate 10 (Figure 4A), forming a sealing layer 12 on one side of the paper substrate 10 by melt molding (Figure 4B), forming a gas barrier layer 14 on one side of the sealing layer 12 (Figure 4C), and further including the step of forming a heat seal layer 16 on one side of the gas barrier layer 14 (Figure 4D). The manufacturing method of the laminate of Embodiment 2 can produce a laminate 1 with excellent gas barrier properties after bending.

[0131] The process for preparing the paper substrate 10 shown in Figure 4A is the same as the process for preparing the paper substrate 10 shown in Figure 2A. Furthermore, the process for forming the sealing layer 12 shown in Figure 4B by melt molding is the same as the process for forming the sealing layer 12 by melt molding shown in Figure 2B.

[0132] (Process for forming a gas barrier layer) As shown in Figure 4C, an anchor coat layer 140 and an inorganic vapor deposition layer 145 are formed in this order as a gas barrier layer 14 on one side of the sealing layer 12. Preferably, an anchor coat layer 140 and an inorganic vapor deposition layer 145 are formed in this order as a gas barrier layer 14 on one side of the sealing layer 12.

[0133] In the process of forming the gas barrier layer 14, preferably, first, an anchor coat layer 140 is formed. The anchor coat layer 140 is formed by applying and drying the anchor coat material on one surface of the sealing layer 12. The application and drying conditions are the same as those for the application and drying of the gas barrier coating material described above.

[0134] Next, an inorganic vapor deposition layer 145 is formed on one surface of the anchor coat layer 140. To form the inorganic vapor deposition layer 145, the inorganic material described above is deposited. As a deposition method, vacuum deposition is one example. In vacuum deposition, as a heating method for the vacuum deposition apparatus, examples include electron beam heating, resistance heating, and induction heating. Resistance heating is preferred. As a condition for vacuum deposition, the vacuum level is, for example, 2.0 × 10⁻⁶. -3 Pa~10.0×10 -3 The pressure is Pa, and the heating conditions are, for example, 30A to 85A.

[0135] The process for forming the heat seal layer 16 shown in Figure 4D is the same as the process for forming the heat seal layer 16 shown in Figure 2D.

[0136] [Differentiation] The present invention includes, but is not limited to, the above-described embodiments 1 and 2. In the above-described embodiments 1 and 2, a sealing layer 12, a gas barrier layer 14, and a heat seal layer 16 are provided on one side of the paper substrate 10. However, the sealing layer 12, gas barrier layer 14, and heat seal layer 16 can also be provided on both sides of the paper substrate 10, one side and the other side. In such a laminate 1, the heat seal layer 16, gas barrier layer 14, sealing layer 12, paper substrate 10, sealing layer 12, gas barrier layer 14, and heat seal layer 16 are provided in order toward one side.

[0137] Furthermore, while Embodiments 1 and 2 described above include a heat seal layer 16, the laminate of the present invention does not necessarily have to include a heat seal layer 16.

[0138] Alternatively, an overcoat layer can be formed on one side of the gas barrier layer 14, and a sheet seal layer 16 can be formed on one side of the overcoat layer. The overcoat layer is positioned between the gas barrier layer 14 and the sheet seal layer 16. The overcoat layer is formed by applying and drying a coating material similar to that used for the heat seal layer 16 to one side of the gas barrier layer 14. [Examples]

[0139] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" and "%" are based on mass. Furthermore, specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0140] [Preparing each ingredient] 1. Preparation of paper substrate As a paper base material, pure white roll (product name: Kinshachi, manufactured by Daio Paper Corporation, basis weight 40g / m²) 2 ), Glossy (bleached) kraft paper (product name: Nagoya Sarashi Ryuo, manufactured by Daio Paper Corporation, basis weight 70, 80, 100, 120, 140 g / m²) 2 ), unbleached paper (product name: Taio Atlas, manufactured by Daio Paper Corporation, basis weight 78 g / m²) 2 ) and cardboard (product name: AURA TNPL, basis weight 170, 200, 230 g / m²) 2 I prepared ).

[0141] 2. Preparation of sealing coating material (1) (Meth)acrylic resin composition (water-dispersible coating material) 50 parts by mass of ethylene-acrylic acid copolymer and 50 parts by mass of ethylene-isobutyl acrylate-methacrylic acid copolymer were melt-kneaded together to obtain a (meth)acrylic resin composition.

[0142] Furthermore, the proportion of constituent units derived from ethylene was 79.5% by mass of the total amount of the ethylene-acrylic acid copolymer, and the proportion of constituent units derived from acrylic acid was 20.5% by mass.

[0143] Furthermore, relative to the total amount of the ethylene-isobutyl acrylate-methacrylic acid copolymer, the content of constituent units derived from ethylene was 80.0% by mass, the content of constituent units derived from isobutyl acrylate was 10.0% by mass, and the content of constituent units derived from methacrylic acid was 10.0% by mass.

[0144] The above (meth)acrylic resin composition, 4.0 parts by mass of potassium hydroxide (neutralizing agent), and 140 parts by mass of deionized water were placed in a reaction vessel and stirred. The contents of the reaction vessel were heated to 150°C and maintained at that temperature for 4 hours. This neutralized the (meth)acrylic resin composition with potassium hydroxide (neutralizing agent). After that, the contents of the reaction vessel were cooled to room temperature (e.g., 25°C).

[0145] This yielded an aqueous dispersion of the neutralized (meth)acrylic resin composition. The solid content concentration of this aqueous dispersion was 42% by mass. The average particle size of this aqueous dispersion was 0.5 μm. This aqueous dispersion was used as an aqueous dispersion coating material.

[0146] (2) Inorganic filler-(meth)acrylic resin composition (water-dispersible coating material) Kaolin (Varisurf HX, manufactured by Imerys) was added to the aqueous dispersion of the neutralized (meth)acrylic resin composition obtained in (1) above, so that the solid content ratio (mass ratio) was (meth)acrylic resin composition:kaolin = 20:80, to obtain an aqueous dispersion of inorganic filler-(meth)acrylic resin composition. This aqueous dispersion was used as an aqueous dispersion coating material.

[0147] (3) Ethylene-(meth)acrylic acid copolymer (molten coating material) An ethylene-(meth)acrylic acid copolymer was produced by copolymerizing ethylene and methacrylic acid. The obtained ethylene-(meth)acrylic acid copolymer was an ethylene-methacrylic acid copolymer with an acid content of 8.0% by mass and a melt mass flow rate (MFR) of 8.0 g / 10 min. Here, the MFR was measured in accordance with JIS K7210-1:2014. The obtained ethylene-(meth)acrylic acid copolymer was used as a molten coating material.

[0148] (4) Ethylene-(meth)acrylic acid copolymer ionomer (melt coating material) The ethylene-(meth)acrylic acid copolymer ionomer was prepared by adding zinc ions as metal ions to the ethylene-(meth)acrylic acid copolymer described in (3) above and neutralizing the mixture. The obtained ethylene-(meth)acrylic acid copolymer ionomer had an MRF of 5.0 g / 10 min. The obtained ethylene-(meth)acrylic acid copolymer ionomer was used as a molten coating material.

[0149] (5) Maleic anhydride-modified polyethylene (melt-coated material) Maleic anhydride-modified polyethylene is linear low-density polyethylene graft-modified with 0.5% by mass of maleic anhydride (MFR at 190°C is 5.0 g / 10 min, density is 0.911 g / cm³). 3 Pellets of ) were used. The resulting maleic anhydride-modified polyethylene pellets were used as a molten coating material.

[0150] (6) Maleic anhydride modified polypropylene (melt-coated material) Maleic anhydride-modified polypropylene is polypropylene grafted with 0.5% by mass of maleic anhydride (MFR at 230°C is 9.2 g / 10 min, density is 0.835 g / cm³). 3 Pellets of ) were used. The resulting maleic anhydride-modified polypropylene pellets were used as a molten coating material.

[0151] (7) Polyethylene (melt-coated material) Polyethylene is linear low-density polyethylene (PE: Mirason 11P, manufactured by Mitsui Dow Polychemicals, MFR (190℃, 2.16kg load) of 7g / 10min, density of 0.92g / cm³). 3 ) was used. The resulting polyethylene was used as a molten coating material.

[0152] (8) Polypropylene (melt-coated material) For the polypropylene used, random polypropylene (PP: Prime Polypropylene F329RA manufactured by Prime Polymer Co., Ltd., MFR (230℃, 2.16kg load) was 27g / 10min). The resulting polypropylene was used as a molten coating material.

[0153] (9) Polyurethane (melt-coated material) Thermoplastic polyurethane (manufactured by Mitsui Chemicals, product name Fortimo XET-T1085, melting point: 98°C) was used as the molten coating material.

[0154] 3. Preparation of gas barrier coating material (1) Preparation of gas barrier coating material (polyurethane resin) (i) Polyurethane dispersion The following components were mixed and reacted under a nitrogen atmosphere at 65-70°C until the isocyanate group concentration (NCO%) was 6.11% by mass or less. This yielded a clear isocyanate-terminated prepolymer reaction product. • 1,3-Xylylene diisocyanate (Takenate 500, 1,3-XDI, manufactured by Mitsui Chemicals): 143.2 parts by mass • Methylenebis(cyclohexyl isocyanate) (Vestanat H12MDI, H12MDI, manufactured by Evonik): 25.0 parts by mass • Ethylene glycol: 29.2 parts by mass Trimethylolpropane: 2.7 parts by mass Dimethylolpropionic acid: 14.8 parts by mass Methyl ethyl ketone (solvent): 121.6 parts by mass

[0155] Next, the reaction product was cooled to 40°C. Then, 11.0 parts by mass of triethylamine (TEA) was added to the reaction product. This neutralized the isocyanate-terminated prepolymer.

[0156] Next, a homodisperser was used to disperse the reaction product in 838.0 parts by mass of deionized water. Then, an aqueous amine solution was added to the resulting dispersion to carry out the chain extension reaction. The reaction product from the chain extension reaction was then aged for 1 hour. This yielded a gas barrier polyurethane resin. The aqueous amine solution was a mixture of 48.4 parts by mass of deionized water and 24.2 parts by mass of 2-((2-aminoethyl)amino)ethanol. Subsequently, an evaporator was used to remove methyl ethyl ketone and deionized water from the reaction product. This adjusted the solid content concentration to 30% by mass.

[0157] Based on the above, a polyurethane dispersion (PUD) was obtained in which a gas barrier polyurethane resin was dispersed in water. The pH of the obtained PUD was 8.6. The average particle size of the PUD was 58 nm.

[0158] (ii) Gas barrier resin composition 30.0 parts by mass of water, the NTS dispersion or MEB dispersion described below, and 0.7 parts by mass of 25% aqueous ammonia (thickening inhibitor) were mixed together and mixed in a mixer for 5 minutes. This obtained a dispersion of the additive.

[0159] NTS dispersion: A swellable, layered dispersion of inorganic compounds (product name: NTS-10NC, synthetic mica, manufactured by Topy Industries, Ltd., solid content concentration 10% by mass) 37.7 parts by mass

[0160] MEB dispersion: A dispersion of swellable layered inorganic compounds (product name: ME-300-B4T, synthetic mica, manufactured by Katakura Co-op Agri Co., Ltd., solid content concentration 7.8%) 28.9 parts by mass

[0161] Next, a dispersion of the above-mentioned additives (49.0 parts by mass) and 51.0 parts by mass of PUD were mixed in a mixer for 5 minutes. This yielded a gas barrier resin composition containing a gas barrier polyurethane resin and a layered inorganic compound. In addition, a gas barrier coating material was obtained in which the PUD and additives were dispersed in water. The solid content concentration of the gas barrier coating material was 15% by mass.

[0162] (2) Preparation of gas barrier coating material (polyvinyl alcohol resin) (i) Polyvinyl alcohol dispersion While stirring 90g of water at room temperature, 10g of polyvinyl alcohol (PVA, Kuraray POVA 20-88 manufactured by Kuraray Co., Ltd., saponification degree 88%) was added and stirred for 1 hour to obtain a PVA dispersion (PVAD).

[0163] Next, the above PVA dispersion (PVAD) was gradually heated up to 80°C, and after reaching 80°C, it was stirred for 2 hours. By returning it to room temperature, a PVA dispersion (PVAD) with a solid content of 10% by mass was obtained.

[0164] (ii) Gas barrier resin composition 47.9 parts by mass of water, 9.6 parts by mass of a dispersion of a swellable layered inorganic compound (product name: ME300B-4T, synthetic mica, manufactured by Katakura Coop Agri Co., Ltd., solid content concentration 7.8%), and 42.5 parts by mass of a PVA dispersion (PVAD) were mixed in a mixer for 5 minutes. This yielded a gas barrier resin composition containing PVA and the layered inorganic compound. A gas barrier coating material was also obtained in which PVAD and the layered inorganic compound were dispersed in water. The solid content concentration of the gas barrier coating material was 5% by mass.

[0165] 4. Preparation of heat-sealable coating material The above (1) (meth)acrylic resin composition (water-dispersible coating material) was used as a heat-sealable coating material.

[0166] 5. Fabrication of the laminate <Laminate of Embodiment 1> The laminates (laminates of Embodiment 1) of Examples 1 to 36 and Comparative Examples 1 to 3 shown in Tables 1 to 6 were manufactured. In each example and each comparative example, the composition (resin type), formation method, and basis weight of each layer were as shown in Tables 1 to 6.

[0167] Note that the "total resin amount" in the table refers to the total mass (g) of the resin contained in 1 m 2 of the laminate (g / m 2 ). In Embodiment 1, the resin is contained in each of the blocking layer, the gas barrier layer, and the heat seal layer.

[0168] (1) Preparation of paper base material Paper base materials having different basis weights as described above were prepared respectively. Note that the paper surfaces of each paper base material were subjected to corona treatment as described below.

[0169] (2) Formation of blocking layer (i) When the blocking resin is an ethylene-(meth)acrylic acid copolymer An extrusion laminator having a 65 mmφ extruder (L / D = 28) was used to subject the paper base material to extrusion coating with an ethylene-(meth)acrylic acid copolymer (melt coating material). Specifically, while extruding the melt film of the ethylene-(meth)acrylic acid copolymer from the die of the extrusion laminator, ozone treatment was performed on the side of the melt film contacting the paper base material, and then the melt film was laminated on the paper surface subjected to corona treatment inline. The detailed conditions of the extrusion coating process were as follows.

[0170] Air gap: 120 mm Processing speed: 120 m / min Processing width: 500 mm Ozone treatment: 25 g / m 3 、1 m 3 / h Corona treatment: 115 W·min / m 2

[0171] Note that when the blocking resin is an ethylene-(meth)acrylic acid copolymer, the resin temperature under the die was set to 290°C.

[0172] (ii) When the sealing resin is an ethylene-(meth)acrylic acid copolymer ionomer Except for setting the die resin temperature to 300°C, the paper substrate was extruded and coated with an ethylene-(meth)acrylic acid copolymer ionomer (molten coating material) in the same manner as in (i).

[0173] (iii) When the sealing resin is maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, or polyethylene Except for setting the die resin temperature to 310°C and the take-up speed (processing speed) to 40 m / min while cooling with a chill roll equipped with pinch rolls after contact between the molten resin and the paper substrate, the paper substrate was extruded and coated with maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, or polyethylene (molten coating material) in the same manner as in (i).

[0174] (iv) When the sealing resin is polypropylene Except for setting the die resin temperature to 290°C and the take-up speed (processing speed) to 40 m / min while cooling with a chill roll equipped with pinch rolls after contact between the molten resin and the paper substrate, the paper substrate was extruded and coated with polypropylene (molten coating material) in the same manner as in (i).

[0175] (v) When the sealing resin is a (meth)acrylic resin composition (aqueous dispersion) or an inorganic filler-(meth)acrylic resin composition (aqueous dispersion) A (meth)acrylic resin composition (water-dispersible coating material) or an aqueous dispersion of an inorganic filler-(meth)acrylic resin composition (water-dispersible coating material) was applied to one side of a paper substrate and dried at 120°C for 60 seconds.

[0176] (3) Formation of a gas barrier layer A gas barrier coating material was applied to one side of the sealing layer and dried at 120°C for 60 seconds.

[0177] (4) Formation of heat seal layer A heat-sealable coating material was applied to one side of the gas barrier layer and dried at 120°C for 60 seconds. The heat-seal layer was formed only on the laminates of Examples 4, 5, 8, 9, 18-21, 27, 29, 30-36, and Comparative Example 3.

[0178] <Laminate of Embodiment 2> Laminates of Examples 37-71 and Comparative Examples 4-6 (laminateds of Embodiment 2) shown in Tables 7-12 were manufactured. In each example and comparative example, the composition (type of resin), formation method, and basis weight of each layer are as shown in Tables 7-12.

[0179] Note that "Total resin amount" in the table refers to 1 m of laminate. 2 The total mass (g) of resin contained in (g / m 2 In Embodiment 2, the resin is contained in the sealing layer, the anchor coat layer, and the heat seal layer, respectively.

[0180] Furthermore, the method for fabricating the laminate in Embodiment 2 is the same as the method for fabricating the laminate in Embodiment 1, except for the formation of the gas barrier layer, and therefore its description is omitted.

[0181] (Formation of a gas barrier layer) In forming the gas barrier layer, first, an anchor coat material containing anchor coat resin was applied to one side of the sealing layer and dried at 120°C for 60 seconds to form the anchor coat layer. As the anchor coat resin, a gas barrier coating material (polyurethane resin) containing the above-mentioned gas barrier polyurethane resin was used.

[0182] Next, the paper substrate (each sample) on which the anchor coat layer has been formed is placed in a vacuum deposition apparatus (ULVAC resistance heating type), and 1 × 10 -4 Under vacuum conditions of Pa, aluminum was deposited onto the surface of each anchor coat layer to form an inorganic vapor-deposited layer. The thickness of the inorganic vapor-deposited layer was 65 nm.

[0183] Note that the heat-sealing layer was formed only for the laminates of Examples 40, 41, 44, 45, 54 to 57, 63, 65 to 71, and Comparative Example 6.

[0184] 6. Evaluation of the laminate (1) Basis weight The weights of the blocking layer, the anchor coat layer, the gas barrier layer, and the heat-sealing layer were measured by the following method. That is, before and after the lamination of each of the above layers, the laminate was allowed to stand at 23°C and 50% relative humidity for 24 hours, and the mass of the laminate was measured. Then, the mass change of the laminate before and after the lamination of each of the above layers was calculated as the mass (g) of each of the above layers. Also, the mass (g) of each layer was divided by the area (m 2 ) of the laminate measured in advance to calculate the weight (g / m 2 ). The results are shown in Tables 1 to 12.

[0185] (2) Smoothness of the blocking layer The smoothness of one side of the blocking layer was measured in accordance with JIS P8155:2010. The results are shown in Tables 1 to 12. Incidentally, the product of the basis weight and the smoothness is shown in Tables 1 to 12.

[0186] (3) Paper ratio (%) The ratio of the mass of the paper base material to the mass of the laminate (mass of paper base material / mass of laminate) was calculated as the paper ratio (%). The results are shown in Tables 1 to 12.

[0187] (4) Oxygen transmission rate (OTR) of the laminate (i) OTR before folding The oxygen transmission amount (cc / m 2 ·day·atm) of the laminate was measured at a temperature of 20°C and a relative humidity of 80% using an oxygen transmission rate measuring device (MOCON, OX-TRAN 2 / 22H). The results are shown in Tables 1 to 12.

[0188] (ii) OTR after folding The laminate was folded twice in the following manner. The first time, the laminate was folded at 2 kg / cm so that the laminated side of each layer was folded inward (valley fold).2 The laminate was bent at a 180° angle for 10 seconds under pressure. For the second time, the bending direction was changed by 90° from the first time so that a cross-shaped crease would be formed, and the laminate was again bent at 2 kg / cm² so that the stacked side of each layer was folded inward (valley fold). 2 The laminate was bent at a 180° angle for 10 seconds under pressure. The OTR of the bent laminate was measured in the same manner as in (i) above. The results are shown in Tables 1 to 12.

[0189] (5) Water vapor transmission rate (WVTR) of the laminate Water vapor transmission rate of laminate (g / m³) 2 The water vapor permeability (·day·atm) was measured using a water vapor transmission meter (MOCON, PERMATRAN-W 3 / 34G) at a temperature of 40°C and a relative humidity of 90%.

[0190] (6) Bag making evaluation Each laminate with a heat-seal layer was prepared. Using each laminate, pillow packaging bags were manufactured using a bag-making machine (Syntegon, SVE2520AR). The bag size was 250mm x 170mm. The bag-making performance was then evaluated according to the following criteria.

[0191] A: The bags could be made without any problems. B: Wrinkles and other defects sometimes occurred during the bag-making process. C: Unable to make bags.

[0192] [Table 1]

[0193] [Table 2]

[0194] [Table 3]

[0195] [Table 4]

[0196]

Table 5

[0197]

Table 6

[0198]

Table 7

[0199]

Table 8

[0200]

Table 9

[0201]

Table 10

[0202]

Table 11

[0203]

Table 12

[0204] Note that the meanings of the alphabetic abbreviations described in Tables 1 to 12 are as follows. PUD: Polyurethane Dispersion [[ID= 73]]PVAD: Polyvinyl Alcohol Dispersion NTS: Synthetic Mica (manufactured by Toppy Industries, solid content concentration 6 mass%) MEB: Synthetic mica (manufactured by Katakura Co-op Chemical Co., Ltd., solid content concentration 7.8% by mass)

[0205] 7. Discussion <Embodiment 1> From the examples and comparative examples shown in Tables 1 to 6, the following observations were made regarding the laminate of Embodiment 1.

[0206] (1) Product of weighing and smoothness in the sealing layer (Comparative Examples 1-3, Examples 1-36) If the product of the weighing and smoothness in the sealing layer is less than 4000, the OTR after bending of the laminate is 200 cc / (m 2 The gas barrier properties after bending were reduced, with the product of the weight and smoothness in the sealing layer being 4000 or more. 2 (day·atm) or less, preferably 30cc / (m 2 (day·atm) or less, more preferably 25cc / (m 2 (day·atm) or less, more preferably 20cc / (m 2 The gas barrier properties after bending the laminate were reduced to below (day·atm) and improved.

[0207] (2) Regarding the sealing resin contained in the sealing layer (Examples 3, 7, 10-14) The sealing resins that produced a low ORT before bending of the laminate, i.e., high gas barrier properties before bending, were, in descending order of quality: ethylene-(meth)acrylic acid copolymer and ethylene-(meth)acrylic acid copolymer ionomer, maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, polyethylene, polypropylene, and polyurethane. Furthermore, the sealing resins that produced a low OTR after bending of the laminate, i.e., high gas barrier properties after bending, were, in descending order of quality: ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer ionomer, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, polyethylene, polypropylene, and polyurethane.

[0208] (3) Regarding the basis weight of the paper substrate (Examples 15 to 17, 30 to 36) When the basis weight of the paper substrate is, for example, 20 g / m 2 or more, preferably 40 g / m 2 or more, more preferably 60 g / m 2 or more, the ORT after folding of the laminate was low, that is, the gas barrier property after folding was high. Also, when the basis weight of the laminate is, for example, 400 g / m 2 or less, preferably 250 g / m 2 or less, more preferably 200 g / m 2 or less, still more preferably 180 g / m 2 or less, particularly preferably 120 g / m 2 or less, particularly preferably 100 g / m 2 or less, the ORT after folding of the laminate was low, that is, the gas barrier property after folding was high. Also, when the basis weight of the laminate including the heat seal layer is preferably 250 g / m 2 or less, more preferably 180 g / m 2 or less, still more preferably 100 g / m 2 or less, the bag-making evaluation of the laminate became high as C, B, A.

[0209] (4) Gas barrier layer (Examples 10, 28, 29) In the gas barrier layer, for a) PUD / NTS, b) PVAD / NTS, and c) PUD / MEB), the OTR before folding of the laminate was, in ascending order, b), a), c), and the OTR after folding of the laminate was, in ascending order, b), c), a). However, for b), the WVTR before folding of the laminate was large and the water vapor barrier property was low.

[0210] (5) Regarding the heat seal layer (i) Regarding the presence or absence of the heat seal layer (Examples 2 to 9) Due to the presence of the heat seal layer, the OTR before folding of the laminate did not change much, but the OTR after folding was small, that is, the gas barrier property after folding was high.

[0211] (ii) Weighing of the heat-sealed layer (Examples 18-21) As the weight of the heat-seal layer increased, the pre-fold OTR of the laminate decreased (i.e., the pre-fold gas barrier properties increased), and the post-fold OTR also decreased (the post-fold gas barrier properties also increased). However, the pre-fold WVTR of the laminate increased (the pre-fold water vapor barrier properties decreased). This is thought to be due to increased hygroscopicity as the weight of the heat-seal layer increased.

[0212] (6) Weighing of laminates (Examples 15-17, 30-36) The weighing capacity of the laminate is, for example, 25 g / m². 2 Preferably 45 g / m² 2 More than 60g / m 2 As a result, the ORT (Oral Temperature Tolerance) of the laminate after bending was low, meaning that the gas barrier properties after bending were high. Also, the weighing capacity of the laminate was, for example, 450 g / m². 2 Preferably 285 g / m² 2 More preferably 235 g / m² 2 More preferably 205 g / m² 2 More preferably, 180 g / m² 2 The following is particularly preferred: 160 g / m² 2 The following is most preferably 120 g / m² 2 When the following conditions are met, the ORT (Oil Temperature Tolerance) after bending of the laminate is low, meaning that the gas barrier properties after bending are high. Furthermore, the weighing of the laminate including the heat seal layer is preferably 285 g / m². 2 Preferably 205 g / m² 2 More preferably, 120 g / m² 2 The following conditions resulted in high bag-making evaluations for the laminated materials, with ratings of C, B, and A.

[0213] <Embodiment 2> From the examples and comparative examples shown in Tables 7 to 12, the following observations were made regarding the laminate of Embodiment 2.

[0214] (1) Product of weighing and smoothness in the sealing layer (Comparative Examples 4-6, Examples 37-71) If the product of the weighing and smoothness in the sealing layer is less than 4000, the OTR after bending of the laminate is 200 cc / (m 2 The result was over (·day·atm), and the gas barrier properties after bending were reduced. If the product of the weighing and smoothness in the sealing layer is less than 4000, the OTR after bending of the laminate is, for example, 35 cc / (m²). 2 The result will be less than or equal to (day·atm), preferably 25cc / (m 2 (day·atm) or less, more preferably 20cc / (m 2 (day·atm) or less, more preferably 15cc / (m 2 The gas barrier properties after bending the laminate were reduced to below (day·atm) and improved.

[0215] (2) Regarding the sealing resin contained in the sealing layer (Examples 39, 43, 46-50) The sealing resins that produced a low ORT before bending of the laminate, i.e., high gas barrier properties before bending, were, in descending order of quality, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer ionomer, maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene and polyethylene, polypropylene, and polyurethane. Furthermore, the sealing resins that produced a low OTR after bending of the laminate, i.e., high gas barrier properties after bending, were, in descending order of quality, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer ionomer, maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, polyethylene, polypropylene, and polyurethane.

[0216] (3) Weighing of paper substrates (Examples 51-53, 65-71) The weighing capacity of the paper substrate is, for example, 20 g / m². 2 Preferably 40 g / m² 2 More than 60g / m 2As a result of the above, the ORT (Oral Temperature Tolerance) of the laminate after bending was low, meaning that the gas barrier properties after bending were high. Also, the basis weight of the laminate was, for example, 400 g / m². 2 The following is preferably 250 g / m 2 More preferably 200g / m 2 When the following conditions are met, the ORT (Oil Temperature Rating) of the laminate after bending is low, meaning that the gas barrier properties after bending are high. Furthermore, the weighing of the laminate including the heat seal layer is preferably 250 g / m². 2 More preferably, 180 g / m² 2 More preferably 100 g / m 2 The following conditions resulted in high bag-making evaluations for the laminated materials, with ratings of C, B, and A.

[0217] (4) Regarding the Cass Barrier Layer (Examples 46, 64) In the gas barrier layer, for a) PUD / NTS and b) PVA / NTS, the pre-fold OTR of the laminate was b) followed by a) in ascending order, and the post-fold OTR of the laminate was b) followed by a) in ascending order. However, b) had a large pre-fold WVTR of the laminate and low water vapor barrier properties.

[0218] (5) Regarding the heat seal layer (i) Regarding the presence or absence of a heat seal layer (Examples 38-45) Due to the presence of the heat seal layer, the OTR of the laminate before bending did not change much, but the OTR after bending was small, meaning that the gas barrier properties after bending were improved.

[0219] (ii) Weighing of the heat-sealed layer (Examples 54-57) As the weight of the heat-seal layer increased, the pre-fold OTR of the laminate did not change much (the gas barrier properties before bending did not change much), but the post-fold OTR decreased (the gas barrier properties after bending also increased). However, the pre-fold WVTR of the laminate increased slightly (the water vapor barrier properties before bending decreased). This is thought to be due to increased hygroscopicity as the weight of the heat-seal layer increased. Since the laminate of Embodiment 2 includes an inorganic vapor-deposited layer as a gas barrier layer, the pre-fold WVTR was maintained at a lower level (the water vapor barrier properties before bending were maintained at a higher level) compared to the laminate of Embodiment 1, which does not include an inorganic vapor-deposited layer in the gas barrier layer.

[0220] (6) Weighing of laminates (Examples 54-57, 65-71) The weighing capacity of the laminate is, for example, 25 g / m². 2 Preferably 45 g / m² 2 More than 60g / m 2 As a result, the ORT (Oral Temperature Tolerance) of the laminate after bending was low, meaning that the gas barrier properties after bending were high. Also, the weighing capacity of the laminate was, for example, 450 g / m². 2 Preferably 285 g / m² 2 More preferably 235 g / m² 2 More preferably 205 g / m² 2 When the following conditions are met, the ORT (Oil Temperature Tolerance) after bending of the laminate is low, meaning that the gas barrier properties after bending are high. Furthermore, the weighing of the laminate including the heat seal layer is preferably 285 g / m². 2 Preferably 205 g / m² 2 More preferably, 120 g / m² 2 The following conditions resulted in high bag-making evaluations for the laminated materials, with ratings of C, B, and A. [Explanation of Symbols]

[0221] 1. Laminate 10 Paper base material 12. Sealing layer 14. Gas barrier layer 16 Heat seal layer 140 Anchor Coat Layer 145 Inorganic Evaporation Layer

Claims

1. The process of preparing the paper substrate, A step of forming a sealing layer on at least one side of the aforementioned paper substrate by melt molding, A method for manufacturing a laminate, comprising the step of forming a gas barrier layer on one side of the sealing layer.

2. The method for producing a laminate according to claim 1, wherein the sealing layer comprises at least one selected from the group consisting of polyurethane, polyolefin, acid-modified polyolefin, olefin-acrylic copolymer, and olefin-acrylic copolymer ionomer.

3. The weighing capacity of the aforementioned paper substrate is 180 g / m². ２ The method for manufacturing a laminate according to claim 1 or 2, which is as follows:

4. The weighing capacity of the aforementioned laminate is 200 g / m². ２ The method for manufacturing a laminate according to claim 3, which is as follows:

Images