Packaging material and method for manufacturing packaging material

Abstract

To provide a packaging material which is excellent in laminate strength and oxygen barrier property after bending, and has a small amount of a residual solvent.SOLUTION: A packaging material has a base material 1, a barrier layer, an adhesive layer and a base material 2, wherein the barrier layer contains a hydrophilic resin, the adhesive layer is a layer containing a cured product of polyol and an isocyanate curing agent (I), a permachor value of the polyol is 25 to 60, a unit area mass of the adhesive layer is 1.0 to 4.5 g / m2, and an olefin percentage content of the packaging material is 80 mass% or more in the total mass of the packaging material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a packaging material and a method for making the packaging material. [Background technology]

[0002] Conventionally, aluminum foil or aluminum-deposited packaging materials have been widely used for packaging materials that require oxygen barrier properties, such as food packaging materials. However, in recent years, in response to environmental issues and other factors, there has been a social demand for thinner packaging materials, simpler lamination, and recyclability, and so there has been a growing movement away from aluminum.

[0003] In addition, in order to provide a barrier property to packaging materials without using aluminum, a film in which a PVDC (polyvinylidene chloride) layer is formed on a plastic film exhibits high oxygen barrier properties not only under low humidity but also under high humidity conditions, and also has a relatively high barrier property against water vapor. However, when this PVDC is incinerated during waste disposal, the chlorine released from it generates chlorine gas and dioxins, which may have a significant adverse effect on the environment and human body, so there is a demand for a shift to other materials.

[0004] Also, when recycling plastic packaging materials, the idea of ​​"mono-material" has been proposed, in which all the base materials constituting the plastic packaging material are made of the same type of base material such as polypropylene. This is a concept that makes it easier to recycle packaging materials, but there is an issue with oxygen barrier properties when only a single base material is used, and using conventional aluminum would hinder recycling, and using coating agents such as PVDC could lead to damage to recycling equipment due to chlorine gas released at high temperatures.

[0005] Known examples of chlorine-free gas barrier materials include adhesive layers provided with gas barrier properties, and laminates using a coating film in which a thermoplastic resin film is coated with polyvinyl alcohol or the like. As an example of a laminate using an adhesive layer imparted with gas barrier properties, an invention has been disclosed (Patent Document 1) in which the laminate has a structure of PET / ester-based adhesive layer / CPP, and the Permacol value of the resin composition for a gas barrier cured product used to form the ester-based adhesive layer is 44 to 60. However, in order to impart sufficient barrier properties to the laminate using only the adhesive layer, the adhesive layer needs to have a large mass per unit area, which poses the problem of residual solvent.

[0006] As an example of a laminate using a coated film, a laminate film having a structure of OPP / urethane anchor coat layer / vinyl alcohol barrier layer / adhesive layer / CPP has been disclosed (Patent Documents 2 and 3). However, even in this laminate film, the adhesive layer has a large unit area mass, and there is a problem of residual solvent.

[0007] Furthermore, when the laminates described in the above Patent Documents 1 to 3 are used as packaging materials, there are likely to be problems with oxygen barrier properties after folding. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2013-129780 A [Patent Document 2] JP 2007-136984 A [Patent Document 3] JP 2001-129915 A Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a packaging material which is excellent in lamination strength and oxygen barrier property after folding, and which contains little residual solvent. Effect of the Invention

[0010] As a result of extensive research into the above problems, the present inventors have found that the above problems can be solved by using the following packaging material, and have thus completed the present invention.

[0011] That is, the present invention relates to the following [1] to

[10] .

[0012] [1] A packaging material having a substrate 1, a barrier layer, an adhesive layer and a substrate 2, the barrier layer comprises a hydrophilic resin, the adhesive layer is a layer containing a cured product of a polyol and an isocyanate curing agent (I), and the polyol has a Permacol value of 25 to 60; The adhesive layer has a unit area mass of 1.0 to 4.5 g / m 2 and A packaging material having an olefin content of 80 mass% or more based on the total mass of the packaging material.

[0013] [2] The packaging material according to [1], wherein the hydrophilic resin is a polyvinyl alcohol-based resin.

[0014] [3] The packaging material according to [1] or [2], wherein the barrier layer further contains an inorganic layered filler.

[0015] [4] The mass of the barrier layer per unit area is 0.7 g / m 2 The packaging material according to any one of [1] to [3] above.

[0016] [5] The packaging material according to any one of [1] to [4], wherein the polyol has a polyester structure.

[0017] [6] The packaging material according to any one of [1] to [5], wherein the ratio of the unit area mass of the barrier layer to the unit area mass of the adhesive layer is 70:30 to 15:85.

[0018] [7] The packaging material according to any one of [1] to [6], further comprising an anchor coat layer, the anchor coat layer containing a urethane resin.

[0019] [8] The packaging material according to [7], wherein the urea bond concentration of the urethane resin is 0.1 to 1.3 mmol / g.

[0020] [9] The packaging material according to any one of [1] to [8], wherein the base material 1 and the base material 2 contain a polyolefin resin.

[0021]

[10] A method for producing a packaging material having a substrate 1, a barrier layer, an adhesive layer, and a substrate 2 in that order, comprising the steps of: A step of applying a barrier coating agent to form a barrier layer; applying a reactive adhesive to form an adhesive layer; the barrier layer comprises a hydrophilic resin, the adhesive layer is a layer made of a reactive adhesive containing a polyol and an isocyanate curing agent (I), and the polyol has a Permacol value of 25 to 60; The adhesive layer has a unit area mass of 1.0 to 4.5 g / m 2 and A method for producing a packaging material, wherein the packaging material has an olefin content of 80 mass% or more based on the total mass of the packaging material.

[0022] According to the present invention, it is possible to provide a packaging material which is excellent in lamination strength and oxygen barrier property after folding, and contains little residual solvent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The following describes in detail the embodiments of the present invention. However, the embodiments or explanations of the requirements described are merely examples of the embodiments of the present invention, and the present invention is not limited to these contents as long as they do not depart from the gist of the present invention.

[0024] [Packaging material] The packaging material has a substrate 1, a barrier layer, an adhesive layer, and a substrate 2, the barrier layer contains a hydrophilic resin, the adhesive layer is a layer containing a cured product of a polyol and an isocyanate curing agent (I), the polyol-derived structure has a Permacol value of 25 to 60, and the adhesive layer has a unit area mass of 1.0 to 4.5 g / m 2The olefin content of the packaging material is 80 mass % or more based on the total mass of the packaging material. The packaging material of the present invention can be suitably used to form a flexible packaging package, a packaging bag, etc. The packaging material of the present invention may be used alone or in combination with other materials. The packaging material may form a packaging container. The olefin content of the packaging material is preferably 80% by mass or more, and more preferably 90 to 99% by mass, based on the total mass of the packaging material. When the olefin content of the packaging material is within the above range, the residual solvent can be reduced.

[0025] In a dry lamination method or the like for forming an adhesive layer, the adhesive is applied to a substrate or the like in a state dissolved in an organic solvent. However, depending on the application conditions and lamination structure, there is a concern that the organic solvent may penetrate into the substrate or the like during application, resulting in a large amount of residual solvent. The packaging material of the present invention has a barrier layer with a specific composition, and the adhesive layer has a polyol-derived structure with a specific Permacol value, which not only improves the barrier properties, but also significantly reduces residual solvents due to the combined effect of the barrier layer, the adhesive layer, and the olefin content of the packaging material. According to one theory, this effect is believed to be due to the promotion of volatilization of the organic solvent derived from the adhesive layer and the prevention of the penetration of the organic solvent into the substrate 1. Due to these effects, the packaging material of the present invention is excellent in lamination strength, residual solvent, and oxygen barrier properties after folding.

[0026] Specific examples of the configuration of the packaging material include, but are not limited to, the following configurations. A configuration having a substrate 1, a barrier layer, and an adhesive layer in this order is preferable, and a configuration having a substrate 1, an anchor coat layer, a barrier layer, an adhesive layer, and a substrate 2 in this order is more preferable. In the following configuration descriptions, " / " indicates the boundary between layers. For example, the adhesive layer may be one formed of an adhesive used in dry lamination, which is a conventionally known method. In the following (1) Substrate 1 / barrier layer / adhesive layer / substrate 2 (2) Substrate 1 / printing layer / barrier layer / adhesive layer / substrate 2 (3) Substrate 1 / anchor coat layer / barrier layer / adhesive layer / substrate 2 (4) Substrate 1 / printing layer / anchor coat layer / barrier layer / adhesive layer / substrate 2 (5) Substrate 1 / printing layer / anchor coat layer / barrier layer / adhesive layer / intermediate substrate / adhesive layer / substrate 2 (6) Printing layer / substrate 1 / anchor coat layer / barrier layer / adhesive layer / substrate 2 In the above configuration example, substrate 1, intermediate substrate, and substrate 2 may be the same or different, and their names are determined by their positional relationship.

[0027] The substrate 1, intermediate substrate, and substrate 2 may each be a single layer, may be laminated with the same or different plastic substrates, or may be laminated with a substrate different from the plastic substrate. In the case of a laminated substrate, it may be in a form including an adhesive layer. The above-mentioned "substrate different from the plastic substrate" may be a paper substrate, etc., and may be of any type. The method of laminating the substrates is not particularly limited, and may be a conventionally known method such as a co-extrusion method, heat fusion, or pressure bonding via an adhesive layer.

[0028] [Base material 1] The substrate 1 is not particularly limited, and examples thereof include paper substrates such as medium-quality paper, wood-free paper, impregnated paper, cardboard, and craft paper, and plastic substrates such as polyethylenes such as biaxially oriented polypropylene (OPP), non-oriented polypropylene (CPP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), polyolefin substrates such as acid-modified polyethylene, acid-modified polypropylene, and copolymerized polypropylene, polyethylene terephthalate, polycarbonate, polylactic acid, polystyrene, AS resin, ABS resin, nylon, polyamide, polyvinyl chloride, polyvinylidene chloride, and cellophane, and substrates made of the above composite materials can also be used. In addition, the substrates may be subjected to deposition of inorganic compounds such as silica, alumina, and aluminum, or coating treatment with polyethylene, polyvinyl alcohol, or the like, or may be subjected to corona treatment.

[0029] Among them, a polyolefin substrate is preferable for the substrate 1. The polyolefin substrate is preferably at least one selected from the group consisting of polyethylene such as biaxially oriented polypropylene (OPP), non-oriented polypropylene (CPP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), acid-modified polyethylene, acid-modified polypropylene, and copolymer polypropylene. The thickness of the substrate 1 is not particularly limited, and in consideration of the processability into packaging containers, it is preferably from 5 μm to 150 μm, more preferably from 10 μm to 70 μm.

[0030] [Base material 2] The substrate 2 is not particularly limited, but in one embodiment, a polyolefin resin, particularly one having heat sealability, can be suitably used. Examples of such a polyolefin resin include corona-treated biaxially oriented polypropylene (OPP) film, high-density polyethylene film (HDPE), non-oriented polypropylene (CPP) film, linear low-density polyethylene (LLDPE) film, and polyethylene resin film formed by melt coating. The substrate 2 may also be coated with a heat seal agent. The thickness of the substrate 2 is not particularly limited, but from the viewpoint of processability during production of the packaging container, it is preferably 5 to 150 μm, and more preferably 10 to 70 μm.

[0031] [Intermediate substrate] The packaging material of the present invention may have an intermediate substrate for the purpose of improving rigidity, etc. A specific example of the intermediate substrate is preferably a plastic substrate mainly containing polyolefin resin as a raw material, similar to the substrate 1 and substrate 2. Examples of the intermediate substrate include polyolefin resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-vinyl acetate copolymer, propylene homopolymer, and ethylene-propylene copolymer. The intermediate substrate may also be a composite substrate produced by a co-extrusion method. Furthermore, it is more preferable that the intermediate substrate is made of the same (same) material as the substrate and substrate 2. Examples of the same (same) material include combinations of polypropylene and polyethylene, etc.

[0032] [Barrier layer] The barrier layer is disposed for the purpose of imparting oxygen barrier properties to the packaging material and reducing residual solvents by the integrated effect with other components, and the barrier layer contains a hydrophilic resin. The barrier layer is preferably formed from a barrier coating agent described below.

[0033] The mass per unit area of ​​the barrier layer is 0.7 to 5 g / m 2 It is preferable that the thickness is 0.8 to 3 g / m 2 More preferably, the thickness is 0.9 to 1.5 g / m 2 It is more preferable that the mass per unit area of ​​the barrier layer is 0.7 g / m 2 If it is equal to or greater than this, the residual solvent can be reduced, and the oxygen barrier properties after folding are also improved. Normally, when the unit area mass of the barrier layer is increased, the amount of organic solvent that may be contained in the composition for forming the barrier layer increases, and it is expected that the amount of residual solvent in the packaging material will also increase; however, in the case of the packaging material of the present invention, the barrier layer acts to prevent the organic solvent from migrating from the adhesive layer to the base material 1, and it is presumed that the integrated effect with the other components further reduces the residual solvent. On the other hand, when the unit area mass of the barrier layer is 5 g / m 2 When it is equal to or less than this, the laminate strength is improved.

[0034] <Hydrophilic resin> The hydrophilic resin refers to a resin that is miscible with water. Examples of hydrophilic resins include polyvinyl alcohol resins (including ethylene vinyl alcohol copolymer resins), aqueous acrylic resins, aqueous styrene-acrylic resins, aqueous styrene-maleic acid resins, aqueous urethane resins, aqueous polylactic acid resins, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and modified resins thereof. These hydrophilic resins can be used alone or in combination of two or more. Among the above, the hydrophilic resin preferably contains a polyvinyl alcohol resin.

[0035] The content of the hydrophilic resin in the total mass of the barrier layer is preferably 30 to 95% by mass, more preferably 55 to 90% by mass, and even more preferably 70 to 80% by mass, in order to improve the oxygen barrier property after bending.

[0036] <Polyvinyl alcohol resin> The polyvinyl alcohol-based resin may be any resin having structural units derived from vinyl alcohol, and it is also preferable that the polyvinyl alcohol-based resin further contains structural units derived from ethylene. Examples of polyvinyl alcohol resins include polyvinyl alcohol resins and ethylene-vinyl alcohol copolymer resins, with polyvinyl alcohol resins and / or ethylene-vinyl alcohol copolymer resins being preferred, and ethylene-vinyl alcohol copolymer resins being more preferred.

[0037] The content of ethylene-derived structural units in the ethylene-vinyl alcohol copolymer resin is preferably 1 to 40 mol%, more preferably 3 to 20 mol%, and even more preferably 5 to 15 mol%. When the content of ethylene-derived structural units is within the above range, the oxygen barrier property after bending is good. The degree of polymerization of the polyvinyl alcohol resin is preferably 100 to 3,000, and more preferably 500 to 2,400. When within the above range, the oxygen barrier property after bending is good.

[0038] The polyvinyl alcohol resin may have a modified functional group, and examples of the functional group include, but are not limited to, a carbonyl group, a silicon group, etc. Also, the polyvinyl alcohol resin may be crosslinked with a crosslinking agent, and examples of the crosslinking agent include known crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, an oxazoline crosslinking agent, and a silane coupling crosslinking agent, and the oxazoline crosslinking agent and the silane coupling crosslinking agent are preferred.

[0039] The degree of saponification of the polyvinyl alcohol resin is represented by the following formula (1), and is preferably 80 mol% or more, more preferably 90 mol%, and more preferably 95 mol%. When it is in the above range, the oxygen barrier property after bending is good. (Formula 1) Saponification degree: (number of hydroxyl groups) / {(number of hydroxyl groups)+(number of acetate groups)}×100 [mol %]

[0040] As the polyvinyl alcohol-based resin, Kuraray Poval R series (polyvinyl alcohol resin, manufactured by Kuraray Co., Ltd.), Kuraray Eval L104B, F104B (ethylene-vinyl alcohol copolymer resin, manufactured by Kuraray Co., Ltd.), etc. can be used.

[0041] <Inorganic layered filler> The barrier layer preferably further contains an inorganic layered filler. The inorganic layered filler here is an inorganic filler that forms a layered structure, and is particularly preferably one that swells and / or cleaves in a solvent. The mass ratio of the hydrophilic resin to the inorganic layered filler is preferably 9:1 to 4:6, more preferably 8:2 to 5:5, and even more preferably 8:2 to 6:4. When the mass ratio is within the above range, the oxygen barrier property after bending is good.

[0042] The average particle size of the inorganic layered filler measured by a laser light scattering method is preferably 0.1 to 30 μm, more preferably 0.5 to 15 μm, further preferably 1 to 10 μm, and particularly preferably 1.5 to 5 μm. In the present invention, the average particle size was measured using MT3300EX II manufactured by Microtrac MRB.

[0043] The aspect ratio of the inorganic layered filler is preferably 10 to 2000, more preferably 50 to 1000, and further preferably 200 to 700. The aspect ratio refers to a value measured with a scanning electron microscope (SEM), and in the present invention, the measurement was performed using a JEOL JSM-7800F.

[0044] The specific surface area of ​​the inorganic layered filler is 0.5 to 250 m 2 / g, and 1 to 100m 2 / g is more preferable, and 3 to 50m 2 More preferably, the range is 5 to 30 m / g. 2 The specific surface area is a value calculated from the amount of nitrogen gas adsorbed by the BET method, and in the present invention, it was measured using a TriStar II manufactured by Shimadzu Corporation.

[0045] Preferred examples of the inorganic layered filler include montmorillonite, beidellite, saponite, hectorite, sauconite, vermiculite, mica, paragonite, lepidolite, margarite, clintonite, anandite, chlorite, donbassite, sudoite, cookeite, clinochlore, chamosite, nimite, tetrasilylic mica, talc, pyrophyllite, nacrite, kaolinite, halloysite, chrysotile, sodium teniolite, xanthophyllite, antigorite, dickite, hydrotalcite, etc., and one or more selected from the group consisting of kaolin, montmorillonite, and mica are preferred, and montmorillonite is more preferred. Montmorillonite has high water absorption and high viscosity after swelling due to its layered structure, so that resin easily penetrates between the layers of the layered filler, contributing to improving the oxygen barrier property of the packaging material after folding.

[0046] These inorganic layered fillers may be naturally occurring or artificially synthesized or modified, or may be treated with an organic substance such as an onium salt.

[0047] The content of the inorganic layered filler is preferably from 1 to 40 mass %, more preferably from 10 to 35 mass %, and further preferably from 20 to 30 mass %, relative to 100 mass % of the barrier layer.

[0048] <Montmorillonite> The above montmorillonite is represented by the following formula 2. Bentonite, which contains montmorillonite as a main component and further contains minerals such as quartz and feldspar, can also be preferably used. (Formula 2) M a Si4(Al 2-a Mg a )O 10 (OH)2 nH2O (In formula 2, M represents a sodium cation, and a is 0.25 to 0.60. The number of water molecules bonded to the ion-exchangeable cations between layers can vary depending on the cation species, humidity, and other conditions, and is therefore represented by nH2O in the formula.)

[0049] Montmorillonite also includes isomorphous ion-substituted products of magnesian montmorillonite, iron montmorillonite, and iron magnesian montmorillonite, which are represented by the following formulas (3) to (5), and these may also be used. (Formula 3) M a Si4(Al 1.67-a Mg 0.5+a )O 10 (OH)2 nH2O (Formula 4) M a Si4(Fe 2-a3 +Mg a )O 10 (OH)2 nH2O (Formula 5) M a Si4(Fe 1.67-a3 +Mg 0.5+a )O 10 (OH)2 nH2O (In formulas 3 to 5, M represents a sodium cation, and a is 0.25 to 0.60.)

[0050] Montmorillonite usually has cations between its layers, but the content varies depending on the place of origin. Examples of the ions include inorganic cations such as sodium ions, calcium ions, magnesium ions, and potassium ions, and organic cations such as quaternary ammonium ions. From the viewpoint of affinity with water, inorganic cations are preferred, and sodium ions and / or calcium ions are more preferred. It is also preferred to use montmorillonite that has been purified by water treatment.

[0051] The average particle size of the montmorillonite is preferably from 0.1 to 10 μm, more preferably from 1 to 5 μm, and even more preferably from 1.5 to 3 μm. The particle aspect ratio of the montmorillonite is preferably 10-2,000, more preferably 100-1,000, and further preferably 300-700. The specific surface area of ​​montmorillonite is 1 to 250 m 2 / g, and 1 to 100m 2 / g is more preferable, and 3 to 50m 2 More preferably, the range is 5 to 30 m / g. 2 It is particularly preferred that the molecular weight is / g.

[0052] The average thickness of the montmorillonite particles is preferably from 0.05 to 30 nm, more preferably from 0.1 to 10 nm, and even more preferably from 0.5 to 3 nm. The average major axis of the montmorillonite particles is preferably from 0.01 to 5 μm, more preferably from 0.05 to 3 μm, and even more preferably from 0.1 to 1 μm. Here, the average thickness and the average major axis of the particles refer to values ​​measured with an atomic force microscope (AFM), and in the present invention, the measurements were performed using an AFM100Plus manufactured by Hitachi High-Technologies Corporation.

[0053] As the montmorillonite, commercially available products such as Kunipia-F and Kunipia-G (manufactured by Kunimine Kogyo Co., Ltd.) can be used.

[0054] <Kaolin> Kaolin is mainly composed of kaolinite (Al2O3·2SiO2·H2O) or halloysite (Al2O3·2SiO2·2H2O), and may be natural or synthetic. Depending on the manufacturing method, there are dry kaolin, wet kaolin, calcined kaolin, etc., but it is not limited to any of them.

[0055] From the viewpoint of oxygen barrier properties after folding, the average particle size of kaolin is preferably from 0.1 to 30 μm, more preferably from 0.2 to 20 μm, and even more preferably from 0.3 to 10 μm. The aspect ratio of kaolin is preferably 10-1,000, more preferably 30-500, and further preferably 50-200. The specific surface area of ​​kaolin is 1 to 250 m 2 / g, and 1 to 100m 2 / g is more preferable, and 3 to 50m 2 More preferably, the range is 5 to 30 m / g. 2 It is particularly preferred that the molecular weight is / g.

[0056] As the kaolin, commercially available products such as Varisurf HX (manufactured by Imerys), NN kaolin clay, and ST kaolin clay (manufactured by Takehara Chemical Industry Co., Ltd.) can be used.

[0057] <Mica> Both natural and synthetic mica can be used. Natural mica is a scaly base material made by crushing mica ore, and the particle size and aspect ratio can be controlled by mechanical crushing or cleavage by calcination. Synthetic mica includes those synthesized by heating industrial raw materials such as SiO2, MgO, Al2O3, K2SiF6, Na2SiF6, melting them at a high temperature of about 1500°C, and then cooling and crystallizing them. Compared to natural mica, it has fewer impurities and is more uniform in size and thickness. Specifically, fluorine mica (KMg3AlSi3O10F2), potassium tetrasilicic mica (KMg 25 AlSi4O10F2), sodium tetrasilicic mica (NaMg 25 AlSiO 10 F2), Na taeniolite (NaMg2LiSi4O10F2), LiNa taeniolite (LiMg2LiSi4O 10 F2) are known. From the viewpoint of dispersibility, synthetic mica that is easy to cleave by intercalation is preferable.

[0058] From the viewpoint of oxygen barrier properties after folding, the average particle size of the mica is preferably 30 μm or less, more preferably 1 to 25 μm, and even more preferably 5 to 15 μm. The aspect ratio of the mica is preferably 30-200, more preferably 70-170, and further preferably 100-150. The specific surface area of ​​mica is 1 to 250 m 2 / g, and 1 to 100m 2 / g is more preferable, and 3 to 50m 2 More preferably, the range is 5 to 30 m / g. 2 It is particularly preferred that the molecular weight is / g.

[0059] As the mica, commercially available products such as Mica Powder TM series, Mica Powder NCF series (manufactured by Yamaguchi Mica Co., Ltd.), L60M, L100M (manufactured by Seishin Enterprise Co., Ltd.) and the like can be used.

[0060] <Additives that can be included in the barrier layer> The barrier layer may contain known additives such as an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity adjuster, a colorant, etc., within the scope of not impairing the effects of the present invention.

[0061] <Barrier coating agent> The barrier coating agent for forming the barrier coating layer preferably contains a hydrophilic resin and an aqueous solvent. Furthermore, each component of the inorganic layered filler can be added to the coating agent alone or in combination, and further, additives can be added as necessary. The barrier coating agent can be obtained, for example, by charging a resin solution in which a hydrophilic resin is dissolved or dispersed in an aqueous solvent, an aqueous solvent, and the above-mentioned optional components as required into a mixer equipped with a stirring blade, rotor, etc. The stirring speed is not particularly limited, and can be performed at 50 to 2000 rpm.

[0062] <Aqueous solvent> The barrier coating agent preferably contains an aqueous solvent. The main component of the aqueous solvent is preferably water, but a hydrophilic organic solvent can be used in addition to water. Specifically, an alcohol-based organic solvent, a glycol-based organic solvent, etc. can be contained depending on the printing conditions (speed, plate depth, design, drying temperature, etc.). Here, the term "mainly water" means that the water content is the largest in the aqueous solvent, and the term "hydrophilic organic solvent" means that the solvent is liquid at 25°C and has a solubility of 1% by mass or more in water at 25°C.

[0063] Examples of the alcohol-based organic solvent include methanol, ethanol, propanol, isopropanol, isobutanol, normal butanol, tertiary butanol, hexanol, octanol, and decanol.

[0064] Examples of the glycol-based organic solvent include acetylene diol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monooctyl ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, propylene glycol, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, and dibutyl glycol. These may be used alone or in combination of two or more.

[0065] <Barrier layer formation> The barrier layer can be formed, for example, by printing on the anchor coat layer using a barrier coating agent, and then removing the volatile components. Printing methods include conventionally known methods such as gravure printing, flexographic printing, dipping, roll coating, screen printing, and spraying, but gravure printing is preferred, and for example, the agent is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing, and is supplied to each printing unit alone or in a mixture, and applied. Thereafter, the coating is fixed by drying in an oven or the like to obtain a barrier coat layer.

[0066] [Adhesive layer] The adhesive layer is a layer containing a cured product of a polyol and an isocyanate curing agent (I). The adhesive layer can be formed, for example, by applying a two-part reactive adhesive, which is a mixture of a polyol having a Permacol value of 25 to 60 and an isocyanate curing agent (I), onto the barrier layer, and then drying and curing the adhesive. The adhesive is preferably in the form of a dry laminate adhesive.

[0067] The mass per unit area of ​​the adhesive layer is 1.0 to 4.5 g / m 2 and 1.5 to 4.3 g / m 2 It is preferable that the thickness is 2.0 to 4.0 g / m 2 When it is in the above range, the oxygen barrier property after bending is improved and the amount of residual solvent is reduced.

[0068] Furthermore, the ratio of the unit area mass of the barrier layer to the unit area mass of the adhesive layer is preferably 70:30 to 15:85, more preferably 55:45 to 22.5:77.5, and even more preferably 40:60 to 20:80. When the ratio of the unit area mass of the barrier layer to the unit area mass of the adhesive layer is within the above range, the oxygen barrier property after bending is improved and the residual solvent is reduced.

[0069] <Permacol value of polyol>

[0070] The Permacol value of the polyol is 25 to 60, preferably 27 to 50, and more preferably 30 to 40. When the Permacol value is 25 or more, the oxygen barrier property after bending is improved. When the Permacol value is 60 or less, the laminate strength is improved and the residual solvent is reduced.

[0071] In the present invention, the Permacol value of a polyol refers to the Permacol value of the residue excluding the terminal OH group of the polyol. The Permacol value is correlated with the gas permeability as shown in (Equation 6), and the larger the Permacol value, the smaller the gas permeability. (Formula 6) P = A × exp(-S × Π) P: Gas permeability A: A constant specific to each gas (oxygen: 5.0 x 10 -9 ) S: A constant specific to each gas (oxygen: 0.112) Π: Permacall value

[0072] The Permacall value of a polyol can be calculated using the following formula (7). For the Permacall value Pn specific to the polymer segment n in formula (7), the values ​​listed in Table 1 of JP 2013-129780 A can be used. (Formula 7)

number

[0073] <Permacol value of cured product of polyol and isocyanate curing agent (I)>

[0074] The Permacol value of the cured product of the polyol and the isocyanate curing agent is 30 to 70, preferably 35 to 60, and more preferably 40 to 50. When the Permacol value is 30 or more, the oxygen barrier property after bending is improved. When the Permacol value is 70 or less, the laminate strength is improved and the residual solvent is reduced.

[0075] In the present invention, the Permacall value of the cured product of polyol and isocyanate curing agent (I) refers to the residues excluding the terminal OH groups of the polyol and the Permacall value of the isocyanate curing agent (I). The Permacall value of the cured product of polyol and isocyanate curing agent (I) can be calculated using the following (Equation 8), and the Permacall value Pm specific to the isocyanate segment m in (Equation 8) can be the values ​​listed in Tables 3 to 7 of JP 2013-129780 A. The isocyanate group of the isocyanate segment is converted to a carbamate group for calculation. (Formula 8)

number

[0076] <Polyol> The polyol may have a Permacol value of 25 to 60. Examples of the polyol include polyester polyol, polyether polyol, polyurethane polyol, polyesteramide polyol, acrylic polyol, polycarbonate polyol, polycaprolactone polyol, polyvalerolactone polyol, polyolefin polyol, polyhydroxyalkane, castor oil, and mixtures thereof, as well as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-5-pentanediol, 1,6-hexanediol, and the like. Glycols such as glycerin, neopentyl glycol, methylpentane glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol; polyalkylene glycols having a number average molecular weight of 200 to 3,000; trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol; and polyols obtained by adding the above-mentioned glycols or polyols to the above-mentioned trifunctional or tetrafunctional aliphatic alcohols can be used. These may be used alone or in combination of two or more kinds. Among them, polyester polyols and polyether polyols are preferred, and polyester polyols are more preferred. The mass ratio of the polyester polyol in the polyol is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, and even more preferably 90 to 100 mass%, based on 100 mass% of the polyol. When it is in the above range, the oxygen barrier property after bending is improved and the residual solvent is reduced.

[0077] Examples of the polyester polyol include aromatic dibasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and naphthalenedicarboxylic acid, aliphatic dibasic acids such as adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, and maleic anhydride, alicyclic dibasic acids such as itaconic anhydride, and dialkyl esters thereof, and mixtures thereof (hereinafter also referred to as carboxyl group components), and ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, butylene glycol, neopentyl glycol, dineopentyl glycol, trimethylolpropane, glycerin, 1,6-hexanediol, 1,4- Examples of the polyester polyol include polyester polyols obtained by esterifying diols such as butanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, 1,9-nonanediol, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol, or a mixture thereof (hereinafter also referred to as a hydroxyl group component); or polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone). The above carboxyl group component and hydroxyl group component may be used in combination of two or more kinds. Among them, it is preferable to contain an aromatic dibasic acid or an aliphatic dibasic acid, and it is more preferable to contain an aromatic dibasic acid. When the above is contained, the oxygen barrier property and low residual solvent after bending are improved. Among aromatic dibasic acids, isophthalic acid and terephthalic acid are preferred, and isophthalic acid is more preferred, and among aliphatic dibasic acids, succinic acid, adipic acid and sebacic acid are preferred, and sebacic acid is even more preferred. As the combination of the dibasic acids, a combination of an aromatic dibasic acid and an aliphatic dibasic acid is preferred, and a combination of isophthalic acid and sebacic acid, or a combination of terephthalic acid and sebacic acid is more preferred, and a combination of isophthalic acid and sebacic acid is even more preferred.

[0078] The content of the aromatic dibasic acid-derived structure in the polyester polyol is preferably 5 to 75 mass%, more preferably 15 to 55 mass%, and even more preferably 25 to 35. When it is in the above range, the oxygen barrier property after bending and the amount of residual solvent are improved. Furthermore, when the content of the linear dibasic acid-derived structure in the polyester polyol is in the above range, preferably 1 to 60, more preferably 5 to 40, and even more preferably 10 to 20, the oxygen barrier property after bending is improved and the amount of residual solvent is reduced.

[0079] Examples of the polyether polyol include polyether diols and polyether triols. Examples of the polyether polyol include polyether diols obtained by polymerizing an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran with a bifunctional low molecular weight polyol such as water, ethylene glycol, or propylene glycol as an initiator; and polyether triols obtained by polymerizing an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran with a low molecular weight triol such as trimethylolpropane or glycerin as an initiator.

[0080] The polyol containing a structural unit derived from a polyester polyol or a structural unit derived from a polyether polyol may be a polyester urethane polyol or a polyether urethane polyol obtained by further reacting the polyester polyol or polyether polyol with a diisocyanate, or may be a polyol obtained by further reacting an acid anhydride with the polyester polyol or polyether polyol. Examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Examples of the acid anhydride include pyromellitic anhydride, mellitic anhydride, trimellitic anhydride, and trimellitic ester anhydride. Examples of the trimellitic ester anhydride include ethylene glycol bisanhydrotrimellitate and propylene glycol bisanhydrotrimellitate.

[0081] The mass average molecular weight (Mw) of the polyol is preferably from 2,000 to 80,000, more preferably from 5,000 to 60,000, and further preferably from 10,000 to 60,000. Furthermore, by using a polyol having a molecular weight distribution (Mw / Mn) of 1.5 to 10, it is possible to improve the leveling property during adhesive application and the lamination strength between layers. In particular, when the polyol contains a structural unit derived from a polyether polyol, the molecular weight distribution (Mw / Mn) is preferably 3.0 to 10.0, and more preferably 3.0 to 8.0. When the polyol contains a structural unit derived from a polyester polyol, the molecular weight distribution (Mw / Mn) is preferably 1.5 to 5.0, and more preferably 2.0 to 4.0.

[0082] The acid value of the polyol is not particularly limited, but is preferably 0 to 50 mgKOH / g, more preferably 0 to 40 mgKOH / g. The hydroxyl value of the polyol is not particularly limited, but is preferably 1 to 200 mgKOH / g, more preferably 3 to 150 mgKOH / g.

[0083] (Isocyanate hardener (I)) The isocyanate curing agent (I) functions as a curing agent in the reactive adhesive, and can be used without any limitation as long as it is for use in ordinary two-liquid reactive adhesives and contains a functional group reactive with a hydroxyl group. By having an isocyanate group, the adhesive strength and cohesive force of the adhesive are increased, and it is possible to cure at a low temperature around room temperature.

[0084] As the isocyanate curing agent (I), diisocyanates or urethane prepolymers which are reaction products of diisocyanates and polyols are preferred, and as such diisocyanates, various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2, Examples of the diisocyanate include 4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer diisocyanate in which the carboxyl group of a dimer acid is converted to an isocyanate group. These can be used alone or in combination of two or more kinds.

[0085] As the isocyanate curing agent (I), a urethane prepolymer having an isocyanate group at the end can be suitably used. Among them, from the viewpoint of preventing yellowing and imparting flexibility to improve laminate strength, it is preferable to use aliphatic diisocyanates such as hexamethylene diisocyanate and xylylene diisocyanate, and alicyclic diisocyanates such as isophorone diisocyanate, and from the viewpoint of compatibility with retort resistance, it is preferable to use trifunctional or higher polyisocyanate compounds such as adducts of trimethylolpropane, isocyanurates, and biurets.

[0086] In the adhesive layer, the functional group equivalent ratio NCO / OH of the hydroxyl group derived from the polyol of the isocyanate curing agent (I) to the isocyanate group derived from the isocyanate resin is preferably 1.5 to 8.0, more preferably 2.0 to 5.0. The adhesive may further contain known components for adhesives in the base agent or curing agent.

[0087] (Reaction accelerator) The adhesive may contain, for example, a reaction accelerator. Examples of reaction accelerators include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; tertiary amines such as 1,8-diaza-bicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene-5,6-dibutylamino-1,8-diazabicyclo(5,4,0)undecene-7; reactive tertiary amines such as triethanolamine; titanium-based, zinc-based, and bismuth-based. These may be used alone or in any combination of two or more. Among them, the use of a titanium-based, zinc-based, or bismuth-based reaction accelerator is preferred because it provides excellent aging effect of the adhesive and resistance to the contents of the packaging material.

[0088] (Silane coupling agent) The adhesive may contain a silane coupling agent, particularly from the viewpoint of improving the adhesive strength to metal-based materials such as metal foil. Examples of the silane coupling agent include trialkoxysilanes having a vinyl group, such as vinyltriethoxysilane and vinyltriethoxysilane; trialkoxysilanes having an amino group, such as 3-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; trialkoxysilanes having a glycidyl group, such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. These may be used alone or in any combination of two or more. The content of the silane coupling agent is preferably 0.1 to 5 mass %, more preferably 0.2 to 3 mass %, based on the total polyol component. By setting the content within the above range, the adhesive strength, particularly to metal-based materials, can be improved.

[0089] (Phosphoric acid or phosphoric acid derivatives) The adhesive may contain phosphoric acid or a phosphoric acid derivative, particularly from the viewpoint of improving the adhesive strength to metal-based materials such as metal foil. The phosphoric acid may be any one having at least one free oxygen acid, and examples thereof include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid; and condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid. Examples of phosphoric acid derivatives include those obtained by partially esterifying the above-mentioned phosphoric acid with alcohols while leaving at least one free oxygen acid. Examples of the alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerin; and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. These may be used alone or in any combination of two or more. The content of phosphoric acid or a derivative thereof is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.05 to 1 mass %, based on the solid content of the two-component reactive adhesive.

[0090] (Leveling agent, defoamer) The adhesive may contain a known leveling agent or defoaming agent. Examples of the leveling agent include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl-containing polydimethylsiloxane, polyetherester-modified hydroxyl-containing polydimethylsiloxane, acrylic copolymer, methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, and lecithin. Examples of the defoaming agent include silicone resins, silicone solutions, and copolymers of alkyl vinyl ethers, alkyl acrylates, and alkyl methacrylates. These can be used alone or in any combination of two or more. The content of each of the leveling agent and the defoaming agent is preferably 0.001 to 1 mass %, more preferably 0.005 to 0.5 mass %, relative to the solid content of the two-component reactive adhesive.

[0091] (Other additives) The adhesive may contain various additives within the range that does not impair the effects of the present invention. Examples of additives include inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes, layered inorganic compounds, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, hydrolysis inhibitors, etc.), rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, fillers, crystal nucleating agents, and catalysts for adjusting the curing reaction.

[0092] (Organic solvents used in adhesives) The adhesive may be diluted with a solvent to adjust the viscosity to an appropriate level. As the organic solvent used in the reactive adhesive, those that are inactive against the polyisocyanate component, such as esters such as ethyl acetate, ketones such as methyl ethyl ketone, and aromatic hydrocarbons such as toluene and xylene, are preferably used, and can be appropriately selected and used.

[0093] [Anchor coat layer] The packaging material of the present invention preferably further includes an anchor coat layer. The anchor coat layer preferably includes a urethane resin. The anchor coat layer is preferably located between the substrate 1 and the barrier layer, and can be formed by an anchor coat agent described later.

[0094] The unit area mass of the anchor coat layer is 0.1 to 5 g / m 2 It is preferable that the thickness is 0.15 to 3 g / m 2 More preferably, the density is 0.2 to 1 g / m 2When the unit area mass of the anchor coat layer is within the above range, the oxygen barrier property and laminate strength during folding are good. From the viewpoint of improving the oxygen barrier property and laminate strength after folding, the mass ratio of the anchor coat layer to the barrier layer is preferably 0.1:1 to 2:1, more preferably 0.15:1 to 1:1, and further preferably 0.2:1 to 0.6:1.

[0095] <Urethane resin> The urethane resin preferably has a urea bond. As a urethane resin having a urea bond, for example, a urethane urea resin obtained by reacting a urethane prepolymer having a terminal isocyanate, which is made of a polyol and a polyisocyanate, with a polyamine chain extender, can be mentioned, and is preferably used.

[0096] The content of the urethane resin in the total mass of the anchor coat layer is preferably 20 to 90 mass%, more preferably 40 to 85 mass%, and even more preferably 60 to 80 mass%, because this improves the oxygen barrier property after bending.

[0097] (urea bond concentration) When the urethane resin has a urea bond, the urea bond concentration is preferably from 0.1 to 1.3 mmol / g, more preferably from 0.3 to 1.15 mmol / g, and further preferably from 0.6 to 0.9 mmol / g. When the urea bond concentration of the urethane resin is 0.1 mmol / g or more, the laminate strength and the oxygen barrier property after folding are further improved. When the urea bond concentration of the urethane resin is 1.3 mmol / g or less,

[0098] Here, the urea binding concentration is a value expressed as follows. When a prepolymer having a terminal isocyanate group is synthesized under conditions such that (number of moles of NCO / number of moles of OH)>1, and then chain-extended with polyamine to give a urethane resin having an amino group at its terminal, the urea bond concentration is expressed by the following formula (9). (Formula 9) Urea bond concentration (mmol / g) = [total number of moles of isocyanate groups (mmol) - total number of moles of hydroxyl groups (mmol)] / total mass of solids (g)

[0099] When a prepolymer having a terminal isocyanate group is synthesized under conditions such that (number of moles of NCO / number of moles of OH)>1, and then chain-extended with polyamine to give a urethane resin having an isocyanate group at its terminal, the urea bond concentration is expressed by the following formula (10). (Formula 10) Urea bond concentration (mmol / g) = (total number of amino group moles (mmol)) / total mass of solids (g) The total number of moles of amino groups herein refers to the total number of moles of primary or secondary amino groups contained in the polyamine used to form urea bonds by reacting with a prepolymer having a terminal isocyanate group.

[0100] (Urethane bond concentration) The urethane bond concentration of the urethane resin is preferably from 0.1 to 1.3 mmol / g, more preferably from 0.3 to 1.15 mmol / g, and further preferably from 0.6 to 0.9 mmol / g. When the urethane bond concentration of the urethane resin is within the above range, the oxygen barrier properties and laminate strength after bending are good.

[0101] Here, the urethane bond concentration is a value expressed as follows. In the raw materials constituting the urethane resin, when (number of moles of NCO / number of moles of OH)>1, the urethane bond concentration is expressed by the following (Equation 11). (Formula 11) Urethane bond concentration (mmol / g) = total number of moles of hydroxyl groups (mmol) / total mass of solids (g) Here, the total number of moles of hydroxyl groups refers to the total number of moles of hydroxyl groups contained in polyols and the like used in the reaction to form urethane, and the total solid content refers to the total mass of non-volatile components that become the urethane resin. In the raw materials constituting the urethane resin, when (number of moles of NCO / number of moles of OH) is less than 1, the urethane bond concentration is expressed by the following formula (12).

[0102] (Formula 12) Urethane bond concentration (mmol / g) = total number of moles of isocyanate groups (mmol) / total mass of solids (g) The total number of moles of isocyanate groups herein refers to the total number of moles of isocyanate groups contained in the polyisocyanate used in the reaction to form urethane.

[0103] The mass average molecular weight of the urethane resin is preferably 10,000 to 100,000, more preferably 20,000 to 85,000, and even more preferably 30,000 to 70,000. When the mass average molecular weight of the urethane resin is within the above range, the oxygen barrier property after bending is good.

[0104] The glass transition temperature of the urethane resin is preferably −80 to 20° C., more preferably −60 to 0° C., and further preferably −40 to −5° C. When the glass transition temperature of the urethane resin is within the above range, the oxygen barrier property after bending is good.

[0105] The amine value of the urethane resin is preferably 0.5 to 20 mgKOH / g, more preferably 1 to 15 mgKOH / g. When the amine value of the urethane resin is within the above range, the oxygen barrier property after bending is good.

[0106] The hydroxyl value of the urethane resin is preferably 0.5 to 30 mgKOH / g, and more preferably 1 to 20 mgKOH / g. When the hydroxyl value of the urethane resin is within the above range, the oxygen barrier property after bending is good.

[0107] The urethane resin preferably contains a structural unit derived from polyester polyol, and the content thereof is preferably 5 to 80 mass %, more preferably 30 to 70 mass %, based on 100 mass % of the urethane resin solid content. When the content of the structural unit derived from polyester polyol is within the above range, the oxygen barrier property after bending is good.

[0108] The method for producing the urethane resin is not particularly limited, and a known method can be used. For example, a urethane resin obtained by reacting a urethane prepolymer having a terminal isocyanate, which is composed of a polyol and a polyisocyanate, with a polyamine and, if necessary, with a polymerization terminator, is preferred.

[0109] More specifically, for example, a prepolymer method in which a polyol and a polyisocyanate are reacted at a temperature of 50°C to 150°C using a solvent inactive to an isocyanate group as necessary, and further using a urethane catalyst as necessary, to produce a prepolymer having an isocyanate group at the end, and then this prepolymer is reacted with a polyamine at 10 to 60°C to obtain a urethane resin, or a one-shot method in which a polymer polyol, a polyisocyanate, and a polyamine (and a polymerization terminator as necessary) are reacted in one step to obtain a urethane resin, etc., can be used. Polyamine can also be used in the urethane reaction of a polyol and a polyisocyanate.

[0110] Examples of the polyol include polyester polyol, polyether polyol, polycaprolactone diol, polycarbonate polyol, polyolefin polyol, castor oil polyol, hydrogenated castor oil polyol, dimer diol, and hydrogenated dimer diol. Among them, polyester polyol is preferable.

[0111] The polyester polyol may be, for example, a condensate obtained by an esterification reaction between a dibasic acid and a diol. Examples of dibasic acids include adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, glutaric acid, 1,4-cyclohexyldicarboxylic acid, dimer acid, hydrogenated dimer acid, etc. Among these, sebacic acid and adipic acid are particularly preferred. Examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 2,4-diethyl-1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether, 2-monoglycerin ether, dimer diol, hydrogenated dimer diol, etc. Among them, polyester polyols consisting of a diol having a branched structure and a dibasic acid are preferred. The branched structure means a diol having an alkyl side chain in which at least one hydrogen atom of the alkylene group contained in the diol is replaced by an alkyl group, and examples thereof include propylene glycol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,4-pentanediol, 3-methyl-1,5-pentanediol, 2,5-hexanediol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, and 2,2,4-trimethyl-1,6-hexanediol. These are particularly preferred because they improve printability, printing effect, and laminate strength. These polyester polyols can be used alone or in combination of two or more. The polyester polyols can also be used in combination with a polyol having three or more hydroxyl groups and / or a polycarboxylic acid having three or more carboxyl groups.

[0112] The number average molecular weight of the polyester polyol is preferably 500 to 10,000. The number average molecular weight of the polyol is calculated by Equation 13. The acid value of the polyester polyol is preferably 1.0 mgKOH / g or less, and more preferably 0.5 mgKOH / g or less. (Formula 13) Number average molecular weight of polyol = 1000 x 56.1 x hydroxyl value / hydroxyl value

[0113] In the production of the urethane resin, the polyol may contain a low molecular weight diol. Such low molecular weight diols preferably have a molecular weight of 50 to 800, and include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 2,4-diethyl-1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether, 2-monoglycerin ether, dimer diol, and hydrogenated dimer diol.

[0114] Examples of the polyisocyanate include various known aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc., which are generally used in the production of urethane resins. Specific examples include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, etc. Examples of the polyisocyanates include cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimer diisocyanate in which the carboxyl group of a dimer acid is converted to an isocyanate group. These may be trimers to form an isocyanurate ring structure. These polyisocyanates may be used alone or in combination of two or more. Among these, tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isocyanurates of hexamethylene diisocyanate are preferred.

[0115] The polyamine is preferably a polyamine having a molecular weight of 500 or less, but is not limited thereto, and examples thereof include diamines and polyfunctional amines, and in addition to diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, pentamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and p-phenylenediamine, diamines having hydroxyl groups such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine can also be used. These polyamines can be used alone or in combination of two or more. In particular, the urethane resin preferably contains a structural unit derived from a polyfunctional polyamine having three or more functional groups. Specific examples of the polyfunctional polyamine include diethylenetriamine, iminobispropylamine (IBPA, 3,3'-diaminodipropylamine), triethylenetetramine, N-(3-aminopropyl)butane-1,4-diamine (spermidine), 6,6-iminodihexylamine, 3,7-diazanonane-1,9-diamine, and N,N'-bis(3-aminopropyl)ethylenediamine. The polyfunctional polyamine preferably has three amino groups. It is further preferable to use it in combination with a diamine. Among these, isophoronediamine, hexamethylenediamine, and iminobispropylamine are preferable.

[0116] The ratio of the total molar number of amino groups in the polyamine to the molar number of isocyanate groups in the prepolymer is preferably from 1.01 to 2.00, and more preferably from 1.03 to 1.06.

[0117] In addition, a monovalent active hydrogen compound can be used as a polymerization terminator for the purpose of stopping an excessive reaction. Examples of such compounds are not particularly limited as long as they are monoamine compounds having a primary or secondary amino group, but include dialkylamines such as di-n-butylamine and amino alcohols such as 2-ethanolamine. Furthermore, when it is particularly desired to introduce a carboxyl group into the urethane resin, amino acids such as glycine and L-alanine can be used as a polymerization terminator. When using a polymerization terminator, a chain extension reaction may be carried out by using the polymerization terminator together with a chain extender (polyamine), or the polymerization may be terminated by adding the polymerization terminator alone after carrying out a certain amount of chain extension reaction with the chain extender. On the other hand, although it is possible to control the molecular weight without using a polymerization terminator, in this case, a method of adding a prepolymer to a solution containing a chain extender is preferable in terms of reaction control. As the polymerization terminator, an amino alcohol is preferable, and its content is preferably 0.01 to 2.0% by mass relative to 100% by mass of the urethane resin.

[0118] In producing the prepolymer, the amounts of polyol and polyisocyanate are preferably adjusted so that the NCO / OH ratio, which is the ratio of the number of moles of isocyanate groups in the polyisocyanate to the number of moles of the total hydroxyl groups in the polymer polyol, is in the range of NCO / OH=1.1 to 3.0, more preferably in the range of NCO / OH=1.3 to 2.5.

[0119] In addition, in terms of reaction control, it is preferable to use an organic solvent for synthesizing the prepolymer. The organic solvent is preferably an organic solvent inactive to an isocyanate group, and examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as dioxane and tetrahydrofuran; and esters such as ethyl acetate, butyl acetate, and propyl acetate. These can be used alone or as a mixed solvent of two or more kinds.

[0120] Furthermore, a catalyst can be used in the synthesis of the prepolymer. Examples of the catalyst include tertiary amine catalysts such as triethylamine and dimethylaniline, and metal catalysts such as tin and zinc. These catalysts are usually used in the range of 0.001 to 1 mol % based on the polyol compound.

[0121] <Resins used in combination with urethane resins> The anchor coat layer preferably contains, in addition to the urethane resin, a vinyl chloride resin, and a co-used resin such as a polyvinyl acetal resin, a cellulose resin, a polyamide resin, etc. The co-used resin is preferably a vinyl chloride resin and / or a polyvinyl acetal resin, and more preferably a vinyl chloride resin. The mass ratio of the urethane resin to the above-mentioned combined resin is preferably 3:7 to 9.9:0.1, more preferably 5:5 to 9.5:0.5, and further preferably 7:3 to 9:1.

[0122] <Vinyl chloride resin> The vinyl chloride resin includes a structure obtained by polymerizing a monomer having an unsaturated double bond (excluding vinyl chloride) and a vinyl chloride monomer. Suitable examples of the vinyl chloride resin include vinyl chloride-acrylic copolymer resin and vinyl chloride-vinyl acetate copolymer resin.

[0123] <Vinyl chloride-acrylic copolymer resin> The vinyl chloride-acrylic copolymer resin is mainly composed of a copolymer of vinyl chloride and an acrylic monomer, and the acrylic monomer is a monomer having an acrylic group or a methacrylic group, and preferably contains an acrylic monomer having a hydroxyl group. (Hereinafter, "acrylic or methacrylic" may be referred to as "(meth)acrylic.") The vinyl chloride-acrylic copolymer resin may be a block copolymer or random copolymer of vinyl chloride and an acrylic monomer, or a graft copolymer in which an acrylic monomer is grafted to the side chain of polyvinyl chloride.

[0124] The mass average molecular weight of the vinyl chloride-acrylic copolymer resin is preferably 10,000 to 100,000, and more preferably 30,000 to 70,000. The glass transition temperature of the vinyl chloride-acrylic copolymer resin is preferably 50 to 90°C, more preferably 55 to 85°C, and even more preferably 65 to 80°C. The hydroxyl value of the vinyl chloride-acrylic copolymer resin is preferably 10 to 120 mgKOH / g, more preferably 20 to 110 mgKOH / g, even more preferably 30 to 100 mgKOH / g, and particularly preferably 40 to 80 mgKOH / g. The content of the vinyl chloride-derived structure in the vinyl chloride-acrylic copolymer resin is preferably 70 to 95 mass% in 100 mass% of the solid content of the vinyl chloride-acrylic copolymer resin.

[0125] Examples of the (meth)acrylic monomer having a hydroxyl group include hydroxyalkyl (meth)acrylate, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate (hydroxyalkyl esters), polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and glycol mono(meth)acrylate such as 1,4-cyclohexanedimethanol mono(meth)acrylate, caprolactone-modified (meth)acrylate, and hydroxyethylacrylamide. Among these, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate are preferred. These can be used alone or in combination of two or more.

[0126] The (meth)acrylic monomer may contain an alkyl (meth)acrylate. The number of carbon atoms of the alkyl group in the alkyl (meth)acrylate is preferably 1 to 20. Examples of the alkyl acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, and octadecyl (meth)acrylate. The alkyl group may have an aromatic ring structure substituted with an aryl group or the like. These may be used alone or in combination of two or more.

[0127] As the vinyl chloride-acrylic copolymer resin, for example, commercially available products such as Solvine A Type Series (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

[0128] <Vinyl chloride-vinyl acetate copolymer resin> The vinyl chloride-vinyl acetate copolymer resin is a resin in which at least vinyl chloride and vinyl acetate are copolymerized, and the mass average molecular weight is preferably 5,000 to 100,000, and more preferably 20,000 to 70,000. In 100% by mass of the solid content of the vinyl chloride-vinyl acetate copolymer resin, the content of the structure derived from the vinyl acetate monomer is preferably 1 to 30% by mass, and the content of the structure derived from the vinyl chloride monomer is preferably 70 to 95% by mass. In addition, the vinyl chloride-vinyl acetate copolymer resin is more preferably one containing a hydroxyl group derived from vinyl alcohol derived from a saponification reaction or copolymerization, in order to improve the solubility in an organic solvent, and the hydroxyl value is preferably 20 to 200 mgKOH / g. In addition, the glass transition temperature of the vinyl chloride-vinyl acetate copolymer resin is preferably 50°C to 90°C.

[0129] As the vinyl chloride-acrylic copolymer resin, commercially available products such as Solvine C type series (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

[0130] <Polyvinyl acetal resin> The polyvinyl acetal resin is obtained by reacting polyvinyl alcohol with an aldehyde such as butylaldehyde to form an acetal, and preferably contains a vinyl alcohol unit, a vinyl acetate unit, and an acetal ring unit. For the acetalization reaction, a known aldehyde such as formaldehyde or acetaldehyde can be used, and two or more kinds of aldehydes can also be used. Examples of polyvinyl acetal resins include polyvinyl formal, polyvinyl acetal, and polyvinyl butyral, with polyvinyl butyral being preferred.

[0131] The content of acetal rings in the polyvinyl acetal resin is preferably 60 to 90% by mass in 100% by mass of the polyvinyl acetal resin. When the content of acetal rings is within the above range, the laminate strength is improved. The content of vinyl alcohol units in the polyvinyl acetal resin is preferably 5 to 30% by mass, more preferably 15 to 25% by mass in 100% by mass of the polyvinyl acetal resin. When the content of vinyl alcohol units is within the above range, the laminate strength is improved. The content of vinyl acetate units in the polyvinyl acetal resin is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass in 100% by mass of the polyvinyl acetal resin. When the content of vinyl acetate units is within the above range, the laminate strength is improved.

[0132] The mass average molecular weight of the polyvinyl acetal resin is preferably 25,000 to 200,000, more preferably 40,000 to 150,000, and even more preferably 7,0000 to 120,000. When the mass average molecular weight of the polyvinyl acetal resin is within the above range, the laminate strength is good. The glass transition temperature of the polyvinyl acetal resin is preferably 50 to 80°C, and more preferably 60 to 75°C. When the glass transition temperature of the polyvinyl acetal resin is within the above range, the laminate strength is good.

[0133] As the polyvinyl acetal resin, commercially available products such as the Mobital series (manufactured by Kuraray, polyvinyl butyral resin), the S-LEC KX series (manufactured by Sekisui Chemical Co., Ltd., polyvinyl acetal resin), and the Vinylec series (manufactured by JNC, polyvinyl formal) can be used.

[0134] <Inorganic pigments> In order to improve the oxygen barrier property after bending, the anchor coat layer preferably contains an inorganic pigment. Examples of inorganic pigments include titanium oxide, zinc oxide, zinc sulfide chromium oxide, aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, silica, barium sulfate, kaolin clay, calcium carbonate, magnesium carbonate, etc., with silica, barium sulfate, kaolin clay, calcium carbonate, and magnesium carbonate being preferred, and silica being particularly preferred.

[0135] The content of the inorganic pigment is preferably from 0.5 to 15% by mass, more preferably from 1 to 10% by mass, and further preferably from 3 to 7% by mass, in 100% by mass of the anchor coat layer.

[0136] <Isocyanate hardener (I')> In order to improve the lamination strength and the oxygen barrier property after bending, it is preferable that the anchor coat layer contains a cured product derived from the isocyanate curing agent (I'). That is, it is preferable that the anchor coating agent for forming the anchor coat layer contains the isocyanate curing agent (I'). When the anchor coating agent contains the isocyanate curing agent (I'), it reacts with the urethane resin or the like, or reacts with the isocyanate curing agent (I') itself to form a cured product. The cured product is preferably a product of the reaction between the urethane resin and the isocyanate curing agent (I'), that is, it has a structure derived from the urethane resin and a structure derived from the isocyanate curing agent (I'). The isocyanate curing agent (I') may be the same as or different from the isocyanate curing agent (I) described in [Adhesive layer].

[0137] Examples of the isocyanate curing agent (I') include aromatic isocyanate curing agents such as m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate; Aliphatic isocyanate curing agents such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate; alicyclic isocyanate curing agents such as cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, and norbornane diisocyanate; an adduct type isocyanate curing agent which is an adduct of the above isocyanate curing agent and a polyhydric alcohol; Among these, aliphatic isocyanate curing agents are preferred, adduct type aliphatic isocyanate curing agents are more preferred, and trifunctional adduct type aliphatic isocyanate curing agents are even more preferred.

[0138] Examples of the polyhydric alcohol include 1,2-propylene glycol (dihydric), diethylene glycol (dihydric), dipropylene glycol (dihydric), 1,3-butanediol (dihydric), neopentyl glycol (dihydric), trimethylolpropane (trihydric), 2,2,4-trimethyl-1,3-pentanediol (trihydric), polyethylene glycol (polyhydric), and polypropylene glycol (polyhydric), and among these, trimethylolpropane is preferred. A trifunctional adduct type aliphatic isocyanate is obtained by reacting a trihydric alcohol with an aliphatic isocyanate curing agent. A suitable example of the adduct type aliphatic isocyanate curing agent is a reaction product of 1,6-hexamethylene diisocyanate and trimethylolpropane.

[0139] As the isocyanate curing agent (I'), commercially available products can be used, such as 24A-100, 22A-75, TPA-100, TSA-100, TSS-100, TAE-100, TKA-100, P301-75E, E402-808, E405-70B, AE700-100, D101, D201, A201H (manufactured by Asahi Kasei Corporation), Mytech Y260A (manufactured by Mitsubishi Chemical Corporation), Coronate CORONATE HX, Coronate CORONATE HL, Coronate CORONATE L (manufactured by Nippon Polyurethane Co., Ltd.), and Desmodur N75MPA / X (manufactured by Bayer AG).

[0140] In the above anchor coat layer, in the cured product consisting of a urethane resin and an isocyanate curing agent (I'), the mass ratio of the structural units derived from the urethane resin to the structural units derived from the isocyanate curing agent (I') is preferably 99:1 to 70:30, more preferably 98:2 to 80:20, and even more preferably 95:5 to 85:15. When a combined resin is contained in addition to the urethane resin, the mass ratio of the total amount of the urethane resin and the combined resin to the isocyanate curing agent (I') is preferably 99:1 to 70:30, more preferably 98:2 to 80:20, and even more preferably 95:5 to 85:15. When the mass ratio of the resin to the isocyanate curing agent (I') is within the above range, the oxygen barrier property and laminate strength after bending are good.

[0141] <Additives> The anchor coat layer preferably contains known additives or structures derived from additives, such as pigment derivatives, dispersants, wetting agents, adhesion aids, leveling agents, defoamers, antistatic agents, trapping agents, antiblocking agents, waxes, silane coupling agents, water, etc.

[0142] <Anchor coating agent> When the anchor coat layer is formed by an anchor coat agent, the anchor coat agent preferably contains a urethane resin. In addition, in order to improve the handling of the anchor coat agent and the oxygen barrier property after folding, optional components such as organic solvents, co-resins, inorganic pigments, and additives can be added to the anchor coat agent alone or in combination.

[0143] The anchor coating agent can be obtained, for example, by feeding a resin solution in which a resin is dissolved in an organic solvent, and an organic solvent into a mixer equipped with a stirring blade, rotor, etc. There are no particular limitations on the stirring speed, and the stirring can be performed at 50 to 2000 rpm.

[0144] <Organic solvent> Examples of organic solvents that can be used in the anchor coating agent include non-aromatic organic solvents such as hydrocarbons such as methylcyclohexane and ethylcyclohexane; ketones such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone; esters such as ethyl acetate, n-propyl acetate, and butyl acetate; and alcohols such as methanol, ethanol, propanol, isopropanol (IPA), and butanol. The organic solvent may be appropriately selected in consideration of reducing the amount of solvent remaining in the film after printing, and one type may be used alone, or two or more types may be mixed and used. The content of the organic solvent is preferably 30 to 95 mass%, more preferably 50 to 90 mass%, and particularly preferably 70 to 85 mass% in 100 mass% of the anchor coating agent.

[0145] In one embodiment, the anchor coating agent preferably contains a glycol ether-based solvent in order to improve the laminate strength. The glycol ether-based solvent is not particularly limited, but examples thereof include ethylene glycol ether and propylene glycol ether. Among them, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether are preferred, and diethylene glycol monoethyl ether is more preferred. The glycol ether-based solvent is preferably 5 to 25% by mass, and particularly preferably 5 to 15% by mass, based on 100% by mass of the organic solvent in the anchor coating agent.

[0146] <Formation of anchor coat layer> The anchor coat layer can be formed, for example, by printing an anchor coat agent on the substrate 1 and then removing the volatile components. Printing methods include conventionally known methods such as gravure printing, flexographic printing, dipping, roll coating, screen printing, and spraying, but gravure printing is preferred. For example, the agent is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing, and is supplied to each printing unit alone or in a mixture and printed. The coating is then fixed by drying in an oven or the like to obtain an anchor coat layer.

[0147] [Print layer] The packaging material of the present invention may have a printed layer. The printed layer preferably contains a resin and a colorant. The printed layer may be a layer that displays any picture, pattern, character, symbol, etc. for the purpose of providing decoration or aesthetics; displaying the contents, expiration date, and manufacturer or seller, etc. The printed layer may be a solid printed layer having no design, pattern, letter, symbol, etc. The method for forming the printed layer is not particularly limited, and the printed layer may be formed, for example, using a printing ink. The printed layer may have a single layer structure or a multi-layer structure, and may be provided on the surface layer.

[0148] [Manufacturing method of packaging materials] The method for producing a packaging material of the present invention is a method for producing a packaging material having a substrate 1, a barrier layer, an adhesive layer, and a substrate 2, and includes a step of applying a barrier coating agent to form a barrier layer, and a step of applying a reactive adhesive to form an adhesive layer, the barrier layer containing a hydrophilic resin, the adhesive layer being a layer made of a reactive adhesive containing a polyol and an isocyanate curing agent (I), the Permacol value of the polyol being 25 to 60, and the unit area mass of the adhesive layer being 1.0 to 4.5 g / m 2 wherein the olefin content of the packaging material is 80 mass % or more based on the total mass of the packaging material. EXAMPLES

[0149] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the present specification, parts and % represent parts by mass and % by mass unless otherwise noted.

[0150] <Hydroxyl value> The hydroxyl value is the number of milligrams of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when 1 g of a sample is acetylated, and was measured by the method described in JIS K 0070. <Acid value> The acid value is the number of milligrams of potassium hydroxide required to neutralize the free fatty acids, resin acids, etc. contained in 1 g of a sample, and was measured by the method described in JIS K 0070.

[0151] <Amine value> The amine value is the amount of potassium hydroxide in mg equivalent to the amount of hydrochloric acid required to neutralize the amino groups contained in 1 g of sample, and was measured in accordance with JIS K 0070. 0.5 to 2 g of sample was precisely weighed out (sample solid content: Sg), and 50 mL of a mixed solution of methanol / methyl ethyl ketone = 60 / 40 (mass ratio) was added to the precisely weighed sample to dissolve it. Bromophenol blue was added as an indicator to the obtained solution, and the obtained solution was titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was set as the end point, and the titration amount (AmL) at this time was used to calculate the amine value according to the following (Equation 13). (Formula 13) Amine value = (A x f x 0.2 x 56.108) / S [mgKOH / g]

[0152] <Mass average molecular weight> The weight average molecular weight was determined by measuring the molecular weight distribution using a gel permeation chromatography (GPC) device (HLC-8220 manufactured by Tosoh Corporation) and calculating the molecular weight converted using polystyrene as a standard substance. The measurement conditions are as follows: Columns: The following columns were used in series connection: Tosoh Corporation TSKgel Super AW2500 Tosoh Corporation TSKgel Super AW3000 Tosoh Corporation TSKgel Super AW4000 Tosoh Corporation's TSK gelguard column Super AWH Detector: RI (differential refractometer) Measurement conditions: Column temperature 40℃ Eluent: Tetrahydrofuran Flow rate: 1.0mL / min

[0153] <Glass transition temperature (Tg)> The glass transition temperature was determined by differential scanning calorimetry (DSC). The measurement was performed using a Rigaku DSC8231 under conditions of a measurement temperature range of -70 to 250°C and a heating rate of 10°C / min. The midpoint (inflection point) of the baseline shift based on the glass transition in the DSC curve was taken as the glass transition temperature.

[0154] <Measurement of unit area mass of each layer> <Anchor coat layer> In the examples described later, for an intermediate laminate obtained during the preparation of the laminate, five 10 cm square pieces were cut out from the component part of the substrate 1 / anchor coat layer, and five 10 cm square pieces were cut out from the substrate 1. The mass of each sample was measured, and the unit area mass of the anchor coat layer was calculated using the following (Equation 14). Note that a uniaxially oriented polyethylene film (MDOPE) with a thickness of 20 μm was used as the substrate 1. (Formula 14) Mass per unit area of ​​anchor coat layer (g / m 2 ) = (average mass of 5 samples of substrate 1 / anchor coat layer) - (average mass of 5 samples of substrate 1)

[0155] <Layers other than the anchor coat layer> For layers other than the anchor coat layer, the unit area mass was calculated in the same manner as for the anchor coat layer, except that the calculation formula and the cut-out location of the sample were different. Note that a low-density polyethylene film (LLDPE) with a thickness of 40 μm was used as the substrate 2. (Formula 15) Barrier layer mass per unit area (g / m 2 ) = (average mass of 5 samples of substrate 1 / anchor coat layer / barrier layer) - (average mass of 5 samples of substrate 1 / anchor coat layer) (Formula 16) Adhesive layer mass per unit area (g / m 2 )=(average mass of five samples of substrate 1 / anchor coat layer / barrier layer / adhesive layer / substrate 2)-{(average mass of five samples of substrate 1 / anchor coat layer / barrier layer)+(average mass of five samples of substrate 2)}

[0156] (Synthesis of polyol) <Synthesis Example 1> Polyol PO1 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube was charged with 150 parts of ethylene glycol, 350 parts of diethylene glycol, 350 parts of isophthalic acid and 150 parts of sebacic acid, and an esterification reaction was carried out at 240°C. After a predetermined amount of water was distilled off, the pressure was gradually reduced to 1 mmHg or less and a deglycolization reaction was carried out at 250°C for 5 hours to obtain a polyester polyol. This polyester polyol was diluted with ethyl acetate to a non-volatile content of 60%, to obtain a polyol PO1 solution. The mass average molecular weight of polyol PO1 was 23,000, the number average molecular weight was 13,500, and the permacol value was 36.0.

[0157] <Synthesis Example 2> Polyol PO2 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube was charged with 420 parts of neopentyl glycol, 373 parts of sebacic acid and 187 parts of adipic acid, and an esterification reaction was carried out at 240 ° C. After a predetermined amount of water was distilled off, the pressure was gradually reduced to 1 mmHg or less and a deglycolization reaction was carried out at 250 ° C. for 5 hours, followed by the addition of 10 parts of isophorone diisocyanate and reacting at 150 ° C. for 2 hours, and then the addition of 10 parts of trimellitic anhydride and reacting at 180 ° C. for 2 hours to obtain a polyester urethane polyol. This polyester urethane polyol was diluted with ethyl acetate to a non-volatile content of 60%, and a polyol PO2 solution was obtained. The mass average molecular weight of polyol PO2 was 25,000, the number average molecular weight was 11,400, and the permacol value was 25.9.

[0158] <Synthesis Example 3> Polyol PO3 A polyol PO3 was obtained in the same manner as in Synthesis Example 2, except that the raw materials and the compounding ratios shown in Table 1 were used.

[0159] <Synthesis Examples 4-6, Comparative Synthesis Example 1> Polyols PO4-6, PO8 Polyols PO4 to PO6 and PO8 were obtained in the same manner as in Synthesis Example 1, except that the raw materials and compounding ratios shown in Table 1 were used.

[0160] <Synthesis Example 7> Polyol PO7 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube was charged with 150 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000, 700 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400, 150 parts of a trifunctional polypropylene glycol having a number average molecular weight of about 400, and 350 parts of tolylene diisocyanate, and the mixture was heated at 80 to 90 ° C for 5 hours while stirring under a nitrogen gas flow to carry out a urethane reaction, thereby obtaining a polyether urethane polyol. 0.1 parts of phosphoric acid and 0.2 parts of DYNASYLAN GLYMO (EVONIK, 3-glycidoxypropyltrimethoxysilane) were added to the obtained polyether urethane polyol, and the solid concentration was adjusted to 60% with ethyl acetate, thereby obtaining a polyol PO7 solution. The mass average molecular weight of polyol PO7 is 36000, the number average molecular weight is 10,000, and the Permacol value is 38.8.

[0161] <Comparative Synthesis Example 2> Polyol PO9 398 parts of ethylene glycol was added to a reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a cooling condenser, and a dropping funnel, and the mixture was stirred while being heated to 70°C. 602 parts of xylylene diisocyanate was slowly dropped thereto over 1 hour. After the dropwise addition, stirring was continued at 70°C for 3 hours to obtain a polyol having a molecular weight of 312 with 2 moles of ethylene oxide added. The weight average molecular weight of polyol PO9 is 500, the number average molecular weight is 312, and the Permacol value is 79.6.

[0162] [Table 1]

[0163] (Isocyanate hardener) Isocyanate curing agent I1: Takenate D-103H (manufactured by Mitsui Chemicals, solid content: 75%, adduct of toluene diisocyanate and trimethylolpropane, solvent: ethyl acetate) Isocyanate hardener I2: Duranate 22A-75PX (Asahi Kasei Corporation, biuret form of hexamethylene diisocyanate, solid content 75%, solvent: ethyl acetate)

[0164] <Preparation Example 1> Isocyanate hardener I3 38 parts of Takenate D-103H and 62 parts of Duranate 22A-75PX were mixed with stirring to obtain an isocyanate curing agent I3.

[0165] <Preparation Example 2> Isocyanate hardener I4 38 parts of Takenate D-103H, 29 parts of Duranate 22A-75PX, and 33 parts of Takenate D-110NB (manufactured by Mitsui Chemicals, Inc., solid content 75%, adduct of xylylene diisocyanate and trimethylolpropane, solvent: ethyl acetate) were mixed with stirring to obtain isocyanate curing agent I4.

[0166] <Synthesis Example 8> Isocyanate hardener I5 23 parts of bifunctional polypropylene glycol having a number average molecular weight of about 2,000, 18 parts of bifunctional polypropylene glycol having a number average molecular weight of about 400, 2 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 30 parts of 4,4'-diphenylmethane diisocyanate were charged into a reaction vessel, and the mixture was heated at 70 to 80 ° C for 7 hours while stirring under a nitrogen gas flow to carry out a urethane reaction. After the reaction was completed, 7 parts of a trimethylolpropane adduct of tolylene diisocyanate were mixed. The mixture was diluted with ethyl acetate to a solid content concentration of 75%, to obtain a polyisocyanate solution containing polyether urethane polyisocyanate. 80 parts of the above polyisocyanate solution and 20 parts of Desmodur L75 (manufactured by Sumika Covestro Urethane Co., Ltd., trimethylolpropane adduct of toluene diisocyanate, NCO group content of 13%, solid content concentration of 75%) were mixed to obtain an isocyanate curing agent I5 solution.

[0167] <Preparation Example 3> Isocyanate hardener I6 38 parts of Takenate D-103H and 62 parts of Takenate D-110NB were mixed with stirring to obtain isocyanate curing agent I6.

[0168] (Synthesis of urethane resin) <Synthesis Example 9> Urethane resin PU1 120.6 parts of ethyl acetate, 153.7 parts of a polyester polyol having a number average molecular weight of 2,000, which is a condensation product of 3-methyl-1,5-pentanediol (MPD) and adipic acid (AdA) (hereinafter "MPD / AdA 2000"), 27.9 parts of a polyester polyol having a number average molecular weight of 5,000, which is a condensation product of 3-methyl-1,5-pentanediol (MPD) and adipic acid (AdA) (hereinafter "MPD / AdA 5000"), 12.4 parts of a polypropylene glycol having a number average molecular weight of 700 (hereinafter "PPG 700"), 35.0 parts of a polypropylene glycol having a number average molecular weight of 2000 (hereinafter "PPG 2000"), and 52.3 parts of isophorone diisocyanate (hereinafter "IPDI") were mixed and reacted at 90°C for 5 hours under a nitrogen atmosphere to obtain a urethane prepolymer with a terminal isocyanate. Next, 279.6 parts of isopropanol, 299.7 parts of ethyl acetate, 2.1 parts of iminobispropylamine (hereinafter "IBPA"), and 16.6 parts of isophoronediamine (hereinafter "IPDA") were mixed with stirring, and the obtained urethane prepolymer with a terminal isocyanate was gradually added at 40° C. The mixture was reacted at 80° C. for 1 hour to obtain a solution of urethane resin PU1 with a solid content of 30% by mass, a urea bond concentration of 0.78 mmol / g, an amine value of 1.3 mgKOH / g, and a mass average molecular weight of 36,100.

[0169] <Synthesis Examples 10 and 11> Urethane resins PU2 and 3 Urethane resins PU2 and 3 were obtained in the same manner as in Synthesis Example 1, except that the raw materials and compounding ratios shown in Table 2 were used.

[0170] [Table 2]

[0171] (Manufacturing of anchor coating agents) <Production Example 1> Anchor Coating Agent AC1 47 parts of urethane resin PU1 solution, 15 parts of vinyl chloride-vinyl acetate resin PVC1 solution (hydroxyl value: 154 mg KOH / g, mass average molecular weight: 28,000, glass transition temperature: 78 ° C., solid mass % = 25%), 1 part of silica particles S1 (Mizusawa Chemical Industry Co., Ltd., Mizukasil P-707, average particle size (laser scattering method): 4 μm, oil absorption: 250 ml / 100 g, solid mass % = 100%), 1 part of chlorinated polypropylene (Nippon Paper Industries Co., Ltd., Super Chron 390S, solid mass % = 50%), 0.5 parts of fatty acid amide solution (lauric acid amide, solid mass % = 50%), 30.5 parts of mixed solvent (normal propyl acetate (NPAC) / isopropyl alcohol (IPA) = 7 / 3), 3 parts of propylene glycol monomethyl ether, and 2 parts of water were mixed and dispersed for 20 minutes with a bead mill to obtain a pigment dispersion. The resulting pigment dispersion was mixed with 20 parts of water with stirring to obtain anchor coating agent AC1.

[0172] <Production Examples 2-4> Anchor Coating Agents AC2-4 Anchor coating agents AC2 to 4 were obtained in the same manner as in Production Example 1, except that the raw materials and compounding ratios were changed as shown in Table 3.

[0173] [Table 3]

[0174] (Manufacturing of barrier coating agents) <Production Example 5> Barrier Coating Agent V1 6 parts of polyvinyl alcohol resin PVA1 (manufactured by Kuraray, Exeval AQ-4104, ethylene vinyl alcohol resin, ethylene content: 6 mol%, solid mass %=100%) and 92 parts of mixed solvent (water / IPA=8 / 2) were heated with stirring, and the heating and stirring were continued at 95°C for 1 hour, after which the heating was stopped and the stirring was continued until the temperature returned to normal, to obtain an aqueous solution of polyvinyl alcohol resin PVA1. Montmorillonite (swelling, average particle size: 2 μm, aspect ratio: 500, specific surface area: 13.1 m) was added to the aqueous solution of polyvinyl alcohol resin PVA1. 2 / g, particle thickness: 1 nm, average major axis: 500 nm, solid content by mass %=100%) were added and mixed and stirred to obtain barrier coating agent V1.

[0175] <Production Examples 6 to 13, Comparative Production Example 1> Barrier Coating Agents V2 to V10 Barrier coating agents V2 to 10 were obtained in the same manner as in Production Example 5, except that the raw materials and compounding ratios were changed to those shown in Table 4. The properties of the raw materials used are as follows. Polyvinyl alcohol resin PVA2: Kuraray Co., Ltd., Kuraray Poval 28-98, polyvinyl alcohol, solid content by mass = 100% Polyvinyl alcohol resin PVA3: Sekisui Chemical Co., Ltd., ULTILOC5003, amine-modified polyvinyl alcohol, solid content mass% = 100% Acrylic resin A1: Nippon Shokubai Co., Ltd., AQUALIC HL415, weight average molecular weight 10,000, solid content weight% = 45% Bentonite: BYK, CLOISITE-Na+ Mica: average particle size: 6 μm, aspect ratio: 100, specific surface area: 9 m 2 / g, solid mass %=100% Kaolin: average particle size 1.2μm, aspect ratio 100, specific surface area 10m 2 / g, solid mass %=100%

[0176] [Table 4]

[0177] (Manufacturing of packaging materials) <Example 1> Packaging material P1 100 parts of anchor coating agent AC1 was diluted with a mixed solvent (isopropyl alcohol / ethyl acetate) to Zahn cup #3 (Rigo Co., Ltd.) 15 seconds (25°C), and then 3 parts of isocyanate curing agent H1 (Asahi Kasei Co., Ltd., Duranate P-301-75E, hexamethylene diisocyanate type (aliphatic), adduct type, solid content 50%) was added and mixed and stirred. Also, 100 parts of barrier coating agent V1 was diluted with a mixed solvent (isopropyl alcohol / water) to Zahn cup #3 (Rigo Co., Ltd.) 16 seconds (25°C). Then, on the surface of a uniaxially oriented polyethylene film (MDOPE) with a thickness of 20 μm, a gravure printing machine equipped with a gravure plate with a plate depth of 15 μm was used to print the anchor coating agent AC1 diluted and added with a curing agent H1 under the conditions of a printing speed of 50 m / min and an in-line oven temperature of 60 ° C. to form an anchor coat layer, and a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm having a non-image portion on one half of the plate was used to print the diluted barrier coating agent V1 twice under the conditions of a printing speed of 50 m / min and an in-line oven temperature of 60 ° C. to form a barrier layer, thereby obtaining an intermediate laminate p1 having a configuration of OPP (substrate 1) / anchor coat layer / barrier layer. Next, polyol PO1 was mixed with ethyl acetate, and then isocyanate curing agent I1 was added and mixed again to obtain an adhesive solution. At this time, the solid content ratio of polyol PO1 to isocyanate curing agent I1 was 95 / 5, and the solid content of the adhesive solution was 23%. Then, using a dry laminator equipped with a gravure plate with a plate depth of 60 μm, an adhesive solution was applied onto the barrier layer of the intermediate laminate p1, and the solvent was dried in an oven to form an adhesive layer. After that, a low-density polyethylene film (LLDPE) with a thickness of 40 μm was laminated onto the adhesive layer at a line speed of 40 m / min and kept at 40°C for one day to obtain a packaging material P1 having a structure of MDOPE (substrate 1) / anchor coat layer / barrier layer / adhesive layer / LLDPE (substrate 2). The unit area mass of the anchor coat layer of the packaging material P1 was 0.4 g / m 2 , the mass per unit area of ​​the barrier layer is 1.0 g / m 2 , the mass of the adhesive layer per unit area is 3.0 g / m 2 It was.

[0178] <Examples 2 to 22 and Comparative Examples 1 to 7> Packaging materials P2 to 29 Packaging materials P2 to P29 were obtained in the same manner as in Example 1, except that the raw materials and coating conditions were changed as shown in Tables 5 and 6.

[0179] (evaluation) The packaging materials obtained in the above Examples and Comparative Examples were subjected to the following evaluations. The results are shown in Tables 5 and 6.

[0180] <Lamination strength> The laminates obtained in the above Examples and Comparative Examples were each cut into a rectangle with a length of 150 mm and a width of 15 mm, and substrate 1 and substrate 2 were peeled off at one end. Next, substrate 1 and substrate 2 were each set in the chuck of a tensile tester, and the laminate strength in the 90° direction was measured and evaluated according to the following criteria. Note that 3 to 5 is within the range where no practical problems occur. Evaluation Criteria 5: 1.5N / 15mm or more 4: 1.2N / 15mm or more, less than 1.5N / 15mm 3: 1.0N / 15mm or more, less than 1.2N / 15mm 2: 0.8N / 15mm or more, less than 1.0N / 15mm 1: Less than 0.8N / 15mm

[0181] <Residual Solvent> The obtained packaging material was cut into 10 rectangular pieces of 50 mm x 10 mm, placed in a headspace vial (Agilent, 75.5 mm x 23 mm), sealed and heated at 80°C for 30 minutes, after which a certain amount of solvent vapor was taken out with a microsyringe, and the amount of volatile solvent was confirmed by gas chromatography (GL Science, GC-4000) and rated according to the following criteria: 3 to 5 is the range where no practical problems occur. Evaluation Criteria 5:2.0mg / m 2 less than 4:2.0mm 2 More than 3.0mg / m 2 less than 3: 3.0 mg / m 2 More than 4.0mg / m 2less than 2:4.0mg / m 2 More than 5.0mg / m 2 less than 1:5.0mg / m 2 End

[0182] <Oxygen barrier properties after bending> The obtained packaging material was cut into 100 mm squares and folded so that the faces of the base material 2 overlapped, and a load of 1 kg / m2 was applied to the folded portion for 5 seconds. The oxygen transmission rate (OTR) of the sample that was unfolded and unfolded was measured using an oxygen transmission rate measuring device OC-TRAN manufactured by MOCON in accordance with JIS K 7162 Method B (constant pressure method) at a temperature of 30°C and a relative humidity of 70%, and evaluated according to the following criteria. Incidentally, a range of 3 to 5 is within the range where no practical problems arise. Evaluation Criteria 5: Oxygen permeability is 100cc / m 2 / day / atm. 4: Oxygen permeability is 100cc / m 2 / day / atm or more, 1000cc / m 2 / day / atm. 3: Oxygen permeability is 1000cc / m 2 / day / atm or more, 1500cc / m 2 / day / atm. 2: Oxygen permeability is 1500cc / m 2 / day / atm or more, 2000cc / m 2 / day / atm. 1: Oxygen permeability is 2000cc / m 2 / day / atm or more.

[0183] [Table 5]

[0184] [Table 5]

[0185] [Table 6]

[0186] From the above results, Comparative Example 1 did not have a barrier layer, and therefore the residual solvent evaluation and the oxygen barrier property after folding were poor. Comparative Example 2 did not have a barrier layer containing a hydrophilic resin, and therefore the residual solvent evaluation and the oxygen barrier property after folding were poor. Comparative Example 3 had a polyol Permacol value of less than 25, and therefore the oxygen barrier property after folding was poor. Comparative Example 4 had a polyol Permacol value of more than 60, and therefore the laminate strength and the residual solvent evaluation were poor. Comparative Example 5 had an adhesive with a unit area mass of 1.0 g / m 2 The laminate strength and the oxygen barrier property after folding were poor. 2 In Comparative Example 7, the olefin content in the packaging material was less than 80% by mass with respect to the total mass of the packaging material, and therefore the residual solvent evaluation was poor. On the other hand, the packaging material of the embodiment has a barrier layer containing a hydrophilic resin, the adhesive layer has a structure derived from a polyol having a Permacol value of 25 to 60, and the unit area mass of the adhesive layer is 1.0 to 4.5 g / m 2 Since the olefin content of the packaging material was 80 mass % or more based on the total mass of the packaging material, it was shown that the present invention can provide a packaging material that is excellent in lamination strength and oxygen barrier property after folding and has little residual solvent.

Claims

1. A packaging material having a substrate 1, a barrier layer, an adhesive layer and a substrate 2, the barrier layer comprises a hydrophilic resin, the adhesive layer is a layer containing a cured product of a polyol and an isocyanate curing agent (I), and the Permacol value of the polyol is 25 to 60; The adhesive layer has a unit area mass of 1.0 to 4.5 g / m ２ and A packaging material, wherein the packaging material has an olefin content of 80 mass% or more based on the total mass of the packaging material.

2. 2. The packaging material according to claim 1, wherein the hydrophilic resin is a polyvinyl alcohol-based resin.

3. The packaging material according to claim 1 or 2, wherein the barrier layer further comprises an inorganic layered filler.

4. The mass per unit area of ​​the barrier layer is 0.7 g / m ２ The packaging material according to claim 1 or 2.

5. 3. The packaging material according to claim 1, wherein the polyol has a polyester structure.

6. 3. The packaging material according to claim 1, wherein the ratio of the mass per unit area of ​​the barrier layer to the mass per unit area of ​​the adhesive layer is from 70:30 to 15:

85.

7. The packaging material according to claim 1 or 2, further comprising an anchor coat layer, the anchor coat layer comprising a urethane resin.

8. The packaging material according to claim 7, wherein the urethane resin has a urea bond concentration of 0.1 to 1.3 mmol / g.

9. The packaging material according to claim 1 or 2, wherein the substrate 1 and the substrate 2 contain a polyolefin resin.

10. A method for producing a packaging material having a substrate 1, a barrier layer, an adhesive layer and a substrate 2, comprising the steps of: A step of applying a barrier coating agent to form a barrier layer; applying a reactive adhesive to form an adhesive layer; the barrier layer comprises a hydrophilic resin, the adhesive layer is a layer made of a reactive adhesive containing a polyol and an isocyanate curing agent (I), the polyol has a Permacol value of 25 to 60; The adhesive layer has a unit area mass of 1.0 to 4.5 g / m ２ and The method for producing a packaging material, wherein the packaging material has an olefin content of 80 mass% or more based on the total mass of the packaging material.

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