Barrier laminate and packaging bag

Abstract

To provide a barrier laminate that combines both water vapor barrier properties and gas barrier properties to an advanced degree even if a barrier layer is only a single layer, and can also reduce the amount of coating to make it possible to decrease the burden on the environment.SOLUTION: A barrier laminate combines both water vapor barrier properties and gas barrier properties to an advanced degree, even with a small number of layers (e.g., even if a barrier layer is only a single layer), and can also reduce the amount of coating to make it possible to decrease the burden on the environment. The barrier laminate has a barrier layer on at least one surface of a paper base material, where the barrier layer contains hydroxy polyurethane, swellable layered silicate, and a cationic resin.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a barrier laminate and a packaging bag using the same.

Background Art

[0002] Packaging materials in which a paper substrate is imparted with gas barrier properties such as oxygen barrier properties and water vapor barrier properties have been conventionally used to prevent deterioration of the quality of contents in the packaging of foods, medical products, electronic components, and the like.

[0003] As a method for imparting water vapor barrier properties and gas barrier properties to a paper substrate, a method of laminating a synthetic resin film having excellent gas barrier properties or the like on the paper substrate is common. However, materials obtained by laminating a synthetic resin film or the like on a paper substrate are difficult to recycle paper, synthetic resin, etc. after use, and have problems in terms of the environment.

[0004] Therefore, the development of gas barrier materials based on paper without using synthetic resin films or the like has been underway. For example, Patent Document 1 describes a technique for controlling the hydroxyl groups and acid groups of the resin used in the gas barrier layer in a paper barrier material in which a gas barrier layer and a heat seal layer are provided in this order on a paper substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The paper barrier material described in Patent Document 1 has a single-layer barrier layer and can reduce the amount of plastic material. However, it is not sufficient from the viewpoint of water vapor barrier properties. The present disclosure provides a barrier laminate that can achieve high compatibility between water vapor barrier properties and gas barrier properties with a small number of layers (for example, even if the barrier layer is a single layer), and can further reduce the coating amount of the barrier layer and reduce the environmental load.

[0007] <1> A barrier laminate having a barrier layer on at least one surface of a paper substrate, wherein the barrier layer is a single layer, the water vapor permeability of the barrier layer at 40 °C and 90% RH is less than 50 g / m 2 ·day, the oxygen permeability of the barrier layer at 23 °C and 50% RH is 10.0 mL / m 2 ·day·atm or less, the water vapor permeability of the barrier laminate measured under the conditions of 40 °C and 90% RH in accordance with JIS-Z-0208:1976 is less than 50 g / m 2 ·day, the oxygen permeability of the barrier laminate at 23 °C and 50% RH when a CPP film is laminated thereto is 10.0 mL / m 2 ·day·atm or less, and the pulp recovery rate after the barrier laminate is redissociated is 85% by mass or more. <2> The barrier laminate according to <1>, wherein the barrier layer contains hydroxy polyurethane and swellable layered silicate. <3> The barrier laminate according to <2>, wherein the barrier layer further contains a cationic resin.

[0008] <4> A barrier laminate having a barrier layer on at least one surface of a paper substrate, wherein the barrier layer contains hydroxy polyurethane, swellable layered silicate and a cationic resin. <5> The barrier laminate according to <3> or <4>, wherein the content ratio of the cationic resin in the barrier layer is 1.0 to 20.0% by mass. <6> The barrier laminate according to any one of <2> to <5>, wherein the content ratio of the hydroxypolyurethane in the barrier layer is 30.0 to 80.0% by mass. <7> The barrier laminate according to any one of <2> to <6>, wherein the content ratio of the swellable layered silicate in the barrier layer is 5.0 to 30.0% by mass.

[0009] <8> The barrier layer further contains at least one selected from the group consisting of a water-suspensible polymer other than hydroxypolyurethane and a water-soluble polymer other than hydroxypolyurethane. The water-suspensible polymer contains at least one selected from the group consisting of a styrene-butadiene copolymer, an acrylic resin, an olefin-unsaturated carboxylic acid copolymer, and a polyolefin resin. The water-soluble polymer contains at least one selected from the group consisting of a vinyl alcohol-based polymer, a (meth)acrylic acid-based polymer, polyethylene glycol, a water-soluble polyamide, polyacrylamide, a polyamine, a polycarboxylic acid, and a water-soluble cellulose derivative. The barrier laminate according to any one of <1> to <7>. <9> The barrier laminate according to <8>, wherein the total content ratio of the water-suspensible polymer other than hydroxypolyurethane and the water-soluble polymer other than hydroxypolyurethane in the barrier layer is 2.0 to 50.0% by mass.

[0010] <10> The barrier laminate further has a heat-seal layer on the side where the barrier layer is laminated. The heat-seal strength when the heat-seal layers of the barrier laminate are peeled off with a tensile tester using a sample obtained by heat-sealing at 150 °C, 0.2 MPa, and for 1 second is 2.0 N / 15 mm or more. The barrier laminate according to any one of <1> to <9>. <11> The total coating amount of the barrier layer and the heat-seal layer is 12 g / m 2 The following. The barrier laminate according to <10>. <12> When a CPP film is laminated on the barrier laminate, the oxygen permeability at 23 ° C and 85% RH is 10.0 mL / m 2 ·day·atm or less, and the barrier laminate according to any one of <1> to <11>. <13> A packaging bag using the barrier laminate according to any one of <1> to <12>.

Mode for Carrying Out the Invention

[0011] In this specification, "X to Y" indicating a range means "X or more and Y or less". When numerical ranges are described stepwise, the upper and lower limits of each numerical range can be arbitrarily combined. Also, in this specification, unless otherwise specified, measurements of operations and physical properties are carried out under the conditions of room temperature (20 to 25 ° C) / relative humidity 40 to 50% RH.

[0012] At least one aspect of the present disclosure (hereinafter also referred to as the first aspect) is a barrier laminate having a barrier layer on at least one surface of a paper substrate, The barrier layer is a single layer, The water vapor permeability of the barrier layer at 40 ° C and 90% RH is 50 g / m 2 ·day or less, The oxygen permeability of the barrier layer at 23 ° C and 50% RH is 10.0 mL / m 2 ·day·atm or less, The water vapor permeability of the barrier laminate measured under the conditions of 40 ° C and 90% RH in accordance with JIS-Z-0208:1976 is 50 g / m 2 ·day or less, The oxygen permeability at 23 ° C and 50% RH when a CPP film is laminated on the barrier laminate is 10 mL / m 2 ·day·atm or less, The pulp recovery rate after the barrier laminate is redissociated is 85% by mass or more.

[0013] At least one aspect of the present disclosure (hereinafter also referred to as the second aspect) is a barrier laminate having a barrier layer on at least one surface of a paper substrate, The barrier layer relates to a barrier laminate containing (A) hydroxy polyurethane, (B) swellable layered silicate, and (C) cationic resin. In the second aspect, even only the barrier layer containing the components (A) to (C) exhibits excellent water vapor barrier properties and gas barrier properties, but it may further have a barrier layer other than the said barrier layer. The inventors of the present invention earnestly studied a barrier laminate that can highly balance water vapor barrier properties and gas barrier properties with a small number of layers (for example, even if the barrier layer is a single layer), and can further reduce the coating amount of the barrier layer. And it has been found that the above problems can be solved by using the said barrier laminate.

[0014] In the first aspect, first, the water vapor permeability of the barrier laminate measured under the conditions of 40 ° C. and 90% RH in accordance with JIS-Z-0208: 1976 is 50 g / m 2 ·day or less. The water vapor permeability is preferably 40 g / m 2 ·day or less, more preferably 30 g / m 2 ·day or less, even more preferably 20 g / m 2 ·day or less, still more preferably 15 g / m 2 ·day or less, even still more preferably 10 g / m 2 ·day or less, particularly preferably 8 g / m 2 ·day or less. Being within the above range indicates that the water vapor barrier property is very high. The lower limit is not particularly limited because the lower it is, the better, but it is preferably 0 g / m 2 ·day or more, 1 g / m 2 ·day or more, 2 g / m 2 ·day or more, 3 g / m 2 ·day or more. The water vapor permeability can be controlled, for example, by the thickness of the barrier layer and the selection of the components contained in the barrier layer.

[0015] Also, the oxygen permeability at 23 ° C. and 50% RH when a CPP film is laminated on the barrier laminate is 10.0 mL / m 2·day·atm or less. The oxygen permeability is 8.0 mL / m 2 ·day·atm or less is preferable, 5.0 mL / m 2 ·day·atm or less is more preferable, 3.0 mL / m 2 ·day·atm or less is even more preferable, 2.0 mL / m 2 ·day·atm or less is even more preferably, 1.5 mL / m 2 ·day·atm or less is still more preferable, 1.0 mL / m 2 ·day·atm or less is particularly preferably, 0.5 L / m 2 ·day·atm or less is particularly preferred. Being within the above range indicates a very high oxygen barrier property. The lower limit is not particularly limited as the lower it is the better, preferably 0.0 mL / m 2 ·day or more, 0.1 mL / m 2 ·day or more. The oxygen permeability can be controlled, for example, by the thickness of the barrier layer and the selection of the components contained in the barrier layer.

[0016] The barrier laminate has a barrier layer on at least one surface of a paper substrate. In a first aspect, the barrier layer is a single layer. And the water vapor permeability of the barrier layer at 40 °C and 90% RH is 50 g / m 2 ·day or less. The water vapor permeability of the above barrier layer is 40 g / m 2 ·day or less is preferable, 30 g / m 2 ·day or less is more preferable, 20 g / m 2 ·day or less is even more preferable, 15 g / m 2 ·day or less is even more preferably, 10 g / m 2 ·day or less is particularly preferably, 8 g / m 2 ·day or less is particularly preferred. The lower limit is not particularly limited as the lower it is the better, preferably 0 g / m 2 ·day or more, 1 g / m 2 ·day or more, 2 g / m 2·day or more, 3 g / m 2 ·day or more. The water vapor permeability of the barrier layer is measured by the measurement method described in the examples below.

[0017] Also, the oxygen permeability of the barrier layer at 23 °C and 50% RH is 10.0 mL / m 2 ·day·atm or less. The oxygen permeability of the above barrier layer is 8.0 mL / m 2 ·day·atm or less is preferable, 5.0 mL / m 2 ·day·atm or less is more preferable, 3.0 mL / m 2 ·day·atm or less is even more preferable, 2.0 mL / m 2 ·day·atm or less is even more preferably, 1.0 mL / m 2 ·day·atm or less is particularly preferably, 0.7 mL / m 2 ·day·atm or less is even more preferably, 0.5 L / m 2 ·day·atm or less is particularly preferable. The lower limit is not particularly limited because the lower it is, the better, but preferably 0.0 mL / m 2 ·day·atm or more, 0.1 mL / m 2 ·day·atm or more. The oxygen permeability of the barrier layer is measured by the measurement method described in the examples below.

[0018] Regarding the first aspect of the present disclosure, the fact that the barrier layer satisfies the above water vapor permeability and oxygen permeability indicates that the water vapor barrier property and gas barrier property of the single barrier layer are very high. And since the above high water vapor barrier property and gas barrier property can be achieved with a single layer, the coating amount of the barrier layer can be reduced, and the weight of the product can be reduced. On the other hand, regarding the second aspect of the present disclosure, since the barrier layer of the barrier laminate contains hydroxy polyurethane, swellable layered silicate, and cationic resin, the maze effect by the swellable layered silicate can be efficiently exhibited. As a result, very high gas barrier properties and water vapor barrier properties can be exhibited, contributing to the solution of the above problems. In addition, the recovery rate of pulp after redissociating the barrier laminate can be increased, the biodegradation performance can be improved, and a barrier laminate capable of reducing the environmental load can be obtained. Furthermore, since the number of layers of the barrier laminate can be reduced, the occurrence of blisters and the like can be suppressed, and manufacturing with a small number of steps becomes possible. In the first aspect, whether the barrier layer is a single layer can be confirmed by preparing a cross-section along the direction perpendicular to the paper plane and observing it with an electron microscope. Alternatively, it can also be confirmed by non-destructive observation using X-ray CT. For example, by selecting the material used for the barrier layer, the water vapor permeability and oxygen permeability can be within the above ranges.

[0019] The recovery rate of pulp after redissociating the barrier laminate is 85% by mass or more. The fact that the recovery rate is within the above range indicates that the pulp content ratio in the barrier laminate is high and the recyclability is high. Also, in combination with satisfying the above-described water vapor permeability and oxygen permeability, it shows that high water vapor barrier properties and gas barrier properties can be achieved with a small coating amount. The recovery rate of the above pulp is preferably 88% by mass or more, more preferably 90% by mass or more, and even more preferably 92% by mass or more. The upper limit is not particularly limited, but is preferably 99% by mass or less, 98% by mass or less, and 97% by mass or less. The recovery rate of the above pulp can be controlled by the coating amount of the barrier layer and the like, the content of the layered inorganic compound (swellable layered silicate) in the barrier layer, the basis weight of the paper substrate, and the like.

[0020] Also, the oxygen permeability at 23°C and 85% RH when a CPP film is laminated on the barrier laminate is 10.0 mL / m 2·day·atm or less, preferably 8.0 mL / m 2 ·day·atm or less, more preferably 5.0 mL / m 2 ·day·atm or less, even more preferably 3.0 mL / m 2 ·day·atm or less, even more preferably 2.0 mL / m 2 ·day·atm or less, particularly preferably 1.5 mL / m 2 ·day·atm or less, still more preferably 1.0 mL / m 2 ·day·atm or less is particularly preferred. The lower limit is not particularly limited as the lower it is, the better, but preferably 0.0 mL / m 2 ·day· atm or more, 0.1 mL / m 2 ·day·atm or more.

[0021] The oxygen permeability at 85% RH satisfying the above range indicates that sufficient gas barrier properties can be exhibited even in a high-humidity environment. The oxygen permeability at 5% RH can be set within the above range depending on the material selected for the barrier layer. Hereinafter, each material of the gas barrier laminate will be described.

[0022] <Paper substrate> The gas barrier laminate includes a paper substrate. The paper substrate is not particularly limited, and known paper materials can be used. The pulp constituting the paper substrate preferably contains plant-derived pulp as the main component, and wood pulp as the main component. Examples of wood pulp include hardwood pulp and softwood pulp. Examples of non-wood pulp include cotton pulp, hemp pulp, kenaf pulp, and bamboo pulp. Materials other than pulp fibers such as synthetic fibers such as rayon fibers and nylon fibers may also be blended as secondary paper materials as long as the effects of the present invention are not impaired.

[0023] As the paper base material, specifically, there may be mentioned bleached kraft paper, unbleached kraft paper, fine paper, cardboard, liner paper, coated paper, semi-bleached kraft paper, glassine paper, graphfan paper, etc. Among these, bleached kraft paper, unbleached kraft paper, fine paper, and semi-bleached kraft paper are preferred. More preferably, bleached kraft paper and semi-bleached paper, and even more preferably semi-bleached kraft paper.

[0024] Additives may be added to the paper base material. Examples of the additives include pH adjusters (such as sodium hydrogen carbonate, sodium hydroxide, etc.), dry paper strengthening agents (such as polyacrylamide, starch, etc.), wet paper strengthening agents (any one of polyamide polyamine epichlorohydrin resin, melamine-formaldehyde resin, urea-formaldehyde resin), internal sizing agents (rosin-based, alkyl ketene dimer, etc.), drainage improvement agents, defoaming agents, fillers (such as calcium carbonate, talc, etc.), dyes, etc. These additives may be used alone or in combination of two or more. The content of the additives is not particularly limited and may be within the range commonly used.

[0025] (Grammage) The grammage of the paper base material is not particularly limited. For example, in the case of packaging bag applications, it is preferably 20 g / m 2 or more and 150 g / m 2 or less, more preferably 30 g / m 2 or more and 100 g / m 2 or less, and even more preferably 40 g / m 2 or more and 70 g / m 2 or less. The grammage of the paper base material is measured in accordance with JIS P 8124:2011.

[0026] (Paper thickness) The paper thickness of the paper base material is not particularly limited. For example, in the case of packaging bag applications, it is preferably 20 μm or more and 150 μm or less, more preferably 25 μm or more and 100 μm or less, and even more preferably 30 μm or more and 50 μm or less. The paper thickness of the paper base material is measured in accordance with JIS P 8118:2014.

[0027] (Wang Yan type smoothness) The smoothness of the paper substrate is not particularly limited. For example, the PPS smoothness of the surface on which the barrier layer is provided is preferably 5 seconds or more, more preferably 10 seconds or more. The upper limit is not particularly limited, but for example, it is preferably 2000 seconds or less, more preferably 1000 seconds or less. The PPS smoothness of the paper substrate is measured in accordance with JIS P 8155:2010.

[0028] (Method for manufacturing paper substrate) Examples of the method for manufacturing a paper substrate include a method of papermaking a paper stock containing pulp. The paper stock may further contain an additive. Examples of the additive include the additives mentioned above.

[0029] The paper stock can be prepared by adding an additive to a pulp slurry. The pulp slurry can be obtained by beating pulp in the presence of water. The beating method and beating device of the pulp are not particularly limited and may be the same as known beating methods and beating devices. The content of pulp in the paper stock is not particularly limited and may be in the range usually used. For example, it is 60% by mass or more and less than 100% by mass based on the total mass of the paper stock.

[0030] Papermaking of the paper stock can be carried out by a conventional method. For example, a method of casting the paper stock onto a wire or the like, dehydrating to obtain wet paper, stacking a plurality of wet papers if necessary, and pressing and drying this single-layer or multi-layer wet paper can be mentioned. At this time, when a plurality of wet papers are not stacked, single-layer paper is obtained, and when a plurality of wet papers are stacked, multi-layer paper is obtained. When stacking a plurality of wet papers, an adhesive may be applied to the surface of the wet paper (the surface on which other wet papers are stacked).

[0031] <Barrier layer> In the first aspect, the barrier laminate has a single-layer barrier layer on at least one surface of the paper substrate. As described above, the barrier layer exhibits high water vapor barrier properties and gas barrier properties. The material used for the barrier layer is not particularly limited as long as it can exhibit the above water vapor barrier properties and gas barrier properties. For example, the following known resins can be adopted.

[0032] Examples of resins that can be used for the barrier layer include polyolefin resins (such as polyethylene and polypropylene), vinyl chloride resins, styrene resins, styrene / butadiene copolymers, acrylonitrile / styrene copolymers, acrylonitrile / butadiene copolymers, ABS resins, AAS resins, AES resins, vinylidene chloride resins, polyurethane resins, poly-4-methylpentene-1 resins, polybutene-1 resins, vinylidene fluoride resins, vinyl fluoride resins, fluororesins, polycarbonate resins, polyamide resins, acetal resins, polyphenylene oxide resins, polyester resins (such as polyethylene terephthalate and polybutylene terephthalate), polyphenylene sulfide resins, polyimide resins, polysulfone resins, polyether sulfone resins, aromatic polyester resins, polyarylate resins, olefin / unsaturated carboxylic acid copolymers, styrene / unsaturated carboxylic acid copolymers, acrylic resins, polyvinyl alcohol and its modified resins, polyacrylic acid and its salts, polysaccharide-based resins such as cellulose derivatives and starch and its derivatives, natural rubbers, natural-derived thermosetting resins such as shellac, and modified products thereof, etc.

[0033] (Hydroxypolyurethane) In the first and second aspects, in order to exhibit high water vapor barrier properties and gas barrier properties, the barrier layer preferably contains hydroxypolyurethane. Hydroxypolyurethane refers to a polyurethane having a hydroxyl group. The hydroxyl value of hydroxypolyurethane is preferably 100 to 500 mgKOH / g, more preferably 150 to 400 mgKOH / g, and even more preferably 200 to 350 mgKOH / g. With the above hydroxyl value, the cohesive force of hydroxypolyurethane increases, and it is easier to exhibit high barrier properties.

[0034] Hydroxypolyurethane may have an acid group. The acid value of hydroxypolyurethane is preferably 50 to 100 mgKOH / g, more preferably 10 to 70 mgKOH / g, and even more preferably 15 to 60 mgKOH / g. The acid value and hydroxyl value of the hydroxy polyurethane can be measured by a titration method in accordance with JIS K 1557:2007.

[0035] Commercially available hydroxy polyurethanes can be used. For example, HPU W-001, HPU W-003, HPU-W013A (all manufactured by Dainichi Seika Chemical Co., Ltd.) and the like can be mentioned. The content ratio of the hydroxy polyurethane in the barrier layer is preferably 30.0 to 80.0% by mass, more preferably 40.0 to 75.0% by mass, still more preferably 50.0 to 70.0% by mass, even more preferably 55.0 to 68.0% by mass, and particularly preferably 60.0 to 66.0% by mass. When it is within the above range, it becomes easier to enhance the water vapor barrier property and gas barrier property. Further, when it is within the above range, the strength of the barrier layer becomes good, and when a heat seal layer is provided on the barrier layer, the heat sealability becomes good.

[0036] (Water-suspended polymer, water-soluble polymer) In the first and second aspects, it is preferable that the barrier layer further contains at least one selected from the group consisting of a water-suspended polymer other than hydroxy polyurethane and a water-soluble polymer other than hydroxy polyurethane. The water-suspended polymer and the water-soluble polymer can be selected from those described above as resins that can be used for the barrier layer.

[0037] The water-suspended polymer other than hydroxy polyurethane preferably contains at least one selected from the group consisting of a styrene-butadiene copolymer, an acrylic resin, an olefin-unsaturated carboxylic acid copolymer, and a polyolefin resin. Water-soluble polymers other than hydroxy polyurethane preferably contain at least one selected from the group consisting of vinyl alcohol-based polymers, (meth)acrylic acid-based polymers, polyethylene glycol, water-soluble polyamides, polyacrylamides, polyamines, polycarboxylic acids, and water-soluble cellulose derivatives, and more preferably contain at least one selected from the group consisting of vinyl alcohol-based polymers and (meth)acrylic acid-based polymers.

[0038] By using such water-suspensible polymers and water-soluble polymers, the film-forming property of the barrier layer can be improved, and the water vapor barrier property and gas barrier property can be improved. When forming the barrier layer by aqueous coating, the water-soluble polymer is superior to the water-suspensible polymer in the effect of improving the film-forming property. Further, from the viewpoint of improving the water resistance of the barrier layer and making the water vapor barrier property better, it is preferable to use the water-suspensible polymer in combination with the water-soluble polymer. That is, the barrier layer preferably contains the water-suspensible polymer and the water-soluble polymer. At this time, as the water-suspensible polymer, an olefin / unsaturated carboxylic acid-based copolymer is preferable, and an ethylene / (meth)acrylic acid copolymer is more preferable. Also, as the water-soluble polymer, a vinyl alcohol-based polymer is preferable. The mass-based ratio (water-suspensible polymer: water-soluble polymer) of the content ratio of the water-suspensible polymer to the content ratio of the water-soluble polymer in the barrier layer is preferably 20:1 to 1:2, more preferably 10:1 to 2:3, still more preferably 5:1 to 3:4, and even more preferably 4:1 to 4:5.

[0039] (Water-suspensible polymer) ≪Styrene / butadiene copolymer≫ Styrene-butadiene copolymers are copolymers obtained by emulsion polymerization of monomers consisting of styrene-based compounds such as styrene, α-methylstyrene, vinyltoluene, p-t-butylstyrene, chlorostyrene, etc., butadiene-based compounds such as 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, etc., and other compounds copolymerizable therewith. As the styrene-based compound, styrene is preferred, and as the butadiene-based compound, 1,3-butadiene is preferred.

[0040] Commercially available styrene-butadiene copolymers can also be used. For example, as an acid-modified styrene-butadiene copolymer binder, LX407S12 (manufactured by Nippon Zeon Co., Ltd.) etc. can be mentioned.

[0041] ≪Styrene / acrylic copolymer≫ Styrene / acrylic copolymers are copolymers obtained by emulsion polymerization of monomers consisting of styrene-based compounds such as styrene, α-methylstyrene, vinyltoluene, p-t-butylstyrene, chlorostyrene, etc., acrylic-based compounds such as acrylic acid, methacrylic acid, (meth)acrylic acid esters, (meth)acrylamidopropanesulfonic acid, (meth)acrylic acid sulfoalkyl sodium salts (alkyl group having 2 or more and 3 or less carbon atoms), etc., and other compounds copolymerizable therewith. As the styrene-based compound, styrene is preferred, and as the acrylic-based compounds, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters are preferred, and acrylic acid, acrylic acid esters are more preferred. As the (meth)acrylic acid ester, an alkyl acrylate is preferred, and the carbon number of the alkyl group is preferably 1 to 6.

[0042] Commercially available styrene / acrylic copolymers can also be used. For example, as a styrene-acrylic copolymer binder, JONCRYL HSL-9012 (manufactured by BASF) etc. can be mentioned.

[0043] ≪Olefin / Unsaturated Carboxylic Acid Copolymer≫ The olefin / unsaturated carboxylic acid copolymer is a copolymer obtained by emulsion polymerization of monomers composed of an olefin, particularly an α-olefin such as propylene or ethylene, and an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, butene tricarboxylic acid, an unsaturated polycarboxylic acid alkyl ester having at least one carboxy group such as monoethyl itaconate, monobutyl fumarate and monobutyl maleate, and other compounds copolymerizable therewith.

[0044] As the olefin, ethylene or an α-olefin is preferable, and ethylene is more preferable. As the unsaturated carboxylic acid monomer, acrylic acid, methacrylic acid, itaconic acid, fumaric acid and the like are suitable.

[0045] As a specific example of the olefin / unsaturated carboxylic acid copolymer, for example, an aqueous dispersion of an ethylene·acrylic acid copolymer ammonium salt is commercially available as Zeicen (registered trademark) AC etc. (copolymerization ratio of acrylic acid 20%, manufactured by Sumitomo Seika Chemicals Co., Ltd.) and can be easily obtained and used.

[0046] ≪Polyolefin Resin≫ As the polyolefin resin, a polymer of ethylene or an α-olefin is preferable, and polyethylene is more preferable. Commercially available polyolefins can also be used. For example, as the polyolefin resin binder, HYDRECT HS (manufactured by DIC Corporation) etc. can be mentioned.

[0047] (Water-soluble polymer) ≪Vinyl Alcohol Polymer≫ Examples of the vinyl alcohol polymer include polyvinyl alcohol. The saponification degree of polyvinyl alcohol is preferably 85.0 to 99.5 mol%, more preferably 90.0 to 99.0 mol%. Commercially available polyvinyl alcohol can be used. It can also be used. For example, the EXCEVAL series (manufactured by Kuraray Co., Ltd.) can be mentioned.

[0048] ≪(Meth)acrylic acid polymer≫ Examples of the (meth)acrylic acid polymer include polyacrylic acid, polymethacrylic acid, and salts thereof. Examples of the salts include sodium poly(meth)acrylate and ammonium poly(meth)acrylate. Commercially available (meth)acrylic acid polymers can also be used. For example, as an aqueous solution of ammonium polyacrylate, Aron A-30 (manufactured by Toagosei Co., Ltd.) can be mentioned.

[0049] In addition, as the water-soluble polymer, known polyethylene glycol, water-soluble polyamide, polyacrylamide, polyamine, polycarboxylic acid, and water-soluble cellulose derivatives can be used. Examples of the polycarboxylic acid include polymaleic acid, acrylic acid-maleic acid copolymer, and polyglucuronic acid. Examples of the water-soluble cellulose derivative include methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, methyl hydroxypropyl cellulose, and methyl hydroxyethyl cellulose.

[0050] The weight average molecular weight of the water-suspensible polymer and the water-soluble polymer is preferably 10,000 or more, more preferably 20,000 or more, and preferably 10,000,000 or less, more preferably 5,000,000 or less. The weight average molecular weight of the water-suspensible polymer is measured using gel permeation chromatography (standard substance: polystyrene). The weight average molecular weight of the water-soluble polymer is measured using gel permeation chromatography (standard substance: polyethylene glycol).

[0051] The total content ratio of water-suspensible polymers other than hydroxypolyurethane and water-soluble polymers other than hydroxypolyurethane in the barrier layer is preferably 2.0 to 50.0% by mass, more preferably 5.0 to 45.0% by mass, still more preferably 10.0 to 35.0% by mass, and even more preferably 15.0 to 25.0% by mass. By being within the above range, it becomes easier to enhance the water vapor barrier property and gas barrier property, and the heat sealability also becomes better.

[0052] (Layered inorganic compound) In a first aspect, in order to more easily enhance the water vapor barrier property and gas barrier property, the barrier layer may contain a layered inorganic compound. The form of the layered inorganic compound is flat plate-like. By using a layered inorganic compound in the barrier layer, it becomes easier for the flat plate-like layered inorganic compound to be laminated substantially parallel to the plane (surface) of the paper substrate. Then, in the plane direction, the area where the layered inorganic compound does not exist becomes small, so the permeation of water vapor is easily suppressed. Also, in the thickness direction, since the flat plate-like layered inorganic compound exists arranged parallel to the paper substrate plane, the water vapor in the layer permeates while detouring around the layered inorganic compound, and due to the maze effect, the permeation of water vapor is suppressed. As a result, the barrier layer is likely to exhibit excellent water vapor barrier property.

[0053] The average thickness of the layered inorganic compound is preferably 200 nm or less. The average thickness of the layered inorganic compound is preferably 120 nm or less, more preferably 50 nm or less, still more preferably 25 nm or less, and particularly preferably 10 nm or less. When the thickness of the layered inorganic compound is smaller, the number of laminations of the layered inorganic compound in the barrier layer becomes larger, so that a high water vapor barrier property can be exhibited. The lower limit value of the thickness of the layered inorganic compound is not particularly limited, but it is preferably 2 nm or more. Here, the average thickness of the layered inorganic compound in the state of being contained in the barrier layer is determined as follows. For the cross-section of the barrier layer, a magnified photograph is taken using an electron microscope. At this time, set the magnification such that about 20 to 30 layered inorganic compounds are included in the screen. Measure the thickness of each individual layered inorganic compound of the layered inorganic compounds within the screen. Then, calculate the average value of the obtained thicknesses, which is taken as the average thickness of the layered inorganic compound. Measure the thickness of each individual layered inorganic compound of the layered inorganic compounds within the screen. Then, calculate the average value of the obtained thicknesses, which is taken as the average thickness of the layered inorganic compound.

[0054] The average length of the layered inorganic compound is preferably 1 μm or more and 100 μm or less. When the average length is 1 μm or more, the layered inorganic compound is likely to be arranged parallel to the paper substrate. Also, when the average length is 100 μm or less, there is less concern that a part of the layered inorganic compound protrudes from the barrier layer. The average length of the layered inorganic compound is more preferably 50 μm or less, still more preferably 30 μm or less, and particularly preferably 15 μm or less. Here, the average length of the layered inorganic compound in the state of being contained in the barrier layer is determined as follows. For the cross-section of the barrier layer, a magnified photograph is taken using an electron microscope. At this time, set the magnification such that about 20 to 30 layered inorganic compounds are included in the screen. Measure the length of each individual layered inorganic compound of the layered inorganic compounds within the screen. Then, calculate the average value of the obtained lengths, which is taken as the average length of the layered inorganic compound. Note that the length of the layered inorganic compound may also be described in terms of particle diameter.

[0055] The layered inorganic compound preferably has an aspect ratio of 50 or more. When the aspect ratio is 50 or more, it is easier to further enhance the water vapor barrier property. The aspect ratio of the layered inorganic compound is preferably 80 or more, more preferably 300 or more, and particularly preferably 500 or more. The larger the aspect ratio, the more the permeation of water vapor is suppressed and the water vapor barrier property is improved. Also, the larger the aspect ratio, the lower the addition amount of the layered inorganic compound can be. The upper limit of the aspect ratio is not particularly limited, and is preferably about 10,000 or less, more preferably about 5,000 or less, and even more preferably about 2,000 or less from the viewpoint of the viscosity of the coating liquid. Here, as described above, the aspect ratio is a value obtained by photographing a magnified image of the cross section of the barrier layer using an electron microscope and dividing the average length of the obtained layered inorganic compound by its average thickness.

[0056] Specific examples of the layered inorganic compound include mica such as mica group and brittle mica group, bentonite, kaolinite (kaolin mineral), pyrophyllite, talc, smectite, vermiculite, chlorite, septchlorite, serpentine, stilpnomelane, montmorillonite, and the like.

[0057] Among these, from the viewpoint of improving the barrier property, it is preferable to contain one or more of mica and bentonite, and mica or bentonite is more preferable. Specific examples of mica include synthetic mica (for example, swelling mica, non-swelling mica), muscovite (mascovite), sericite (sericite), phlogopite (phlogopite), biotite (biotite), fluorophlogopite (synthetic mica), red mica, soda mica, vanadium mica, illite, tin mica, paragonite, brittle mica, and the like. Specific examples of bentonite include montmorillonite.

[0058] In the first and second aspects, as the layered inorganic compound, the barrier layer preferably contains a swellable layered silicate such as swellable mica. The barrier layer preferably contains hydroxypolyurethane and a swellable layered silicate. The swellable layered silicate is a layered inorganic compound that has swellability with respect to water and whose layers are easily cleaved by shear to a thickness on the order of nanometers. By combining hydroxypolyurethane and a swellable layered silicate, thin and high aspect ratio swellable layered silicates are dispersed in the hydroxypolyurethane resin film which originally has high gas barrier performance, and higher gas barrier performance is exhibited due to the maze effect. Examples of the swellable layered silicate include sodium tetrasilicate mica, sodium hectorite, lithium teniolite, fluorophlogopite, sodium smectite, sodium montmorillonite and the like. The swellable layered silicate is preferably a swellable mica such as sodium tetrasilicate mica. Among commercially available swellable layered silicates, examples of the swellable mica include NTO-05 (manufactured by Toppan Industries) and Somasilf ME300B-4T (manufactured by Katakura Koppu Agri Co., Ltd.).

[0059] The content ratio of the swellable layered silicate in the barrier layer is preferably 5.0 to 30.0% by mass, more preferably 10.0 to 25.0% by mass, and even more preferably 13.0 to 24.0% by mass. Being within the above range makes it easier to further enhance the water vapor barrier property and gas barrier property.

[0060] (Cationic resin) In the first and second aspects, the barrier layer preferably further contains a cationic resin in addition to hydroxypolyurethane and a swellable layered silicate. By containing a cationic resin in the barrier layer, the gas barrier property and water vapor barrier property, particularly the water vapor barrier property, are greatly improved, and it becomes easier to achieve the oxygen permeability and water vapor permeability within the specific ranges described above. Since the surface of the particles of the swellable layered silicate is easily negatively charged and the end faces of the particles are easily positively charged, the surface and the end faces tend to attract each other to form a card-house aggregation structure. By adding a cationic resin, the anionic groups on the particle surface can be blocked with cations, and the card-house aggregation structure can be destroyed. Therefore, the three-dimensional aggregation of the swellable layered silicate can be suppressed, and the swellable layered silicate can be aligned parallel to the plane of the paper substrate, and the maze effect can be fully exhibited. As a result, very high gas barrier properties and water vapor barrier properties can be exerted.

[0061] Specific examples of the cationic resin include polyalkylene polyamine, polyamide compound, modified polyamide-based compound, polyamideamine-epihalohydrin or formaldehyde condensation reaction product, polyamine-epihalohydrin or formaldehyde condensation reaction product, polyamidepolyurea-epihalohydrin or formaldehyde condensation reaction product, polyaminepolyurea-epihalohydrin or formaldehyde condensation reaction product, polyamideaminepolyurea-epihalohydrin or formaldehyde condensation reaction product, polyamidepolyurea compound, polyaminepolyurea compound, polyamideaminepolyurea compound and polyamideamine compound, polyethyleneimine, polyvinylpyridine, amino-modified acrylamide-based compound, polyvinylamine, polydiallyldimethylammonium chloride and the like. Among them, the cationic resin is preferably a modified polyamide compound, and more preferably a modified polyamide resin. Commercially available products may be used as the modified polyamide resin, for example, SPI203(50)H, manufactured by Tago Chemical Industry Co., Ltd., and the like.

[0062] The content of the cationic resin in the barrier layer may be appropriately selected according to the types of materials used in the barrier layer, such as hydroxypolyurethane and swellable layered silicate. From the viewpoint of further improving the barrier property and / or heat sealability, the content ratio of the cationic resin in the barrier layer is preferably 1.0 to 20.0% by mass, more preferably 1.0 to 10.0% by mass, still more preferably 1.5 to 8.0% by mass, even more preferably 1.8 to 5.0% by mass, and particularly preferably 2.0 to 3.0% by mass.

[0063] The surface charge of the cationic resin is preferably 0.1 to 10 meq / g, more preferably 0.1 to 5.0 meq / g, still more preferably 0.1 to 4.0 meq / g, even more preferably 0.1 to 2.0 meq / g, and particularly preferably 0.2 to 1.0 meq / g. When the surface charge of the cationic resin is not less than the above lower limit, the effect of adding the cationic resin can be obtained more sufficiently. On the other hand, when the surface charge is not more than the above upper limit, while suppressing the aggregation of the swellable layered silicate, the effect of the cationic resin can be more sufficiently exerted. The surface charge of the cationic resin is measured by the method described below. First, the polymer used as a sample is dissolved in water to obtain a solution with a polymer concentration of 1 ppm. To this solution, 0.001 N sodium polyethylene sulfonate is dropped using a charge analyzer Mutek PCD-04 type (manufactured by BTG) to measure the charge amount.

[0064] In the barrier layer, a dispersant, a surfactant, an antifoaming agent, a wetting agent, a dye, a color adjuster, a thickener, etc. can be added as appropriate as long as the specific barrier property is not impaired.

[0065] (Coating amount of the barrier layer) The coating amount of the barrier layer is not particularly limited, but from the viewpoint of the barrier property, as the solid content after drying, it is preferably 1 g / m 2 or more, more preferably 2 g / m 2The above, and from the perspective of re-dissociability, is preferably 15 g / m 2 or less, more preferably 10 g / m 2 or less, still more preferably 8 g / m 2 or less, and even more preferably 6 g / m 2 or less. The thickness of the barrier layer is preferably 1 to 20 μm, more preferably 2 to 10 μm.

[0066] (Method for forming the barrier layer) The method for forming the barrier layer is not particularly limited. For example, a barrier layer coating liquid is prepared by dispersing at least one resin selected from the group consisting of water-suspensible polymers and water-soluble polymers other than hydroxypolyurethane, hydroxypolyurethane, swellable layered silicate, and cationic resin in a solvent. It is preferable to apply the obtained barrier layer coating liquid to a paper substrate and dry it to form a barrier layer.

[0067] The solvent for the barrier layer coating liquid is not particularly limited, and water or an organic solvent such as ethanol, isopropyl alcohol, methyl ethyl ketone, or toluene can be used. Among these, from the perspective of not causing problems with volatile organic solvents, the dispersion medium for the barrier layer coating liquid is preferably an aqueous medium, and more preferably water. In this specification, an aqueous medium is a medium containing 50% by mass or more of water.

[0068] The apparatus used for coating the barrier layer coating liquid is not particularly limited, and it may be appropriately selected from commonly used coating apparatuses. For example, various known coating apparatuses such as an air knife coater, a blade coater, a gravure coater, a rod blade coater, a roll coater, a reverse roll coater, a Mayer bar coater, a curtain coater, a die slot coater, a champlex coater, a metering blade type size press coater, a short dwell coater, a spray coater, a gate roll coater, and a lip coater can be mentioned.

[0069] <Heat seal layer> In the first and second aspects, the barrier laminate may further have a heat-sealing layer on the side where the barrier layer is laminated. In the first aspect, even when the heat-sealing layer has barrier properties, if it is provided for the purpose of imparting heat-sealing properties, it shall be classified as a heat-sealing layer. In the first aspect, the heat-sealing layer, for example, does not satisfy both the ranges of water vapor permeability and oxygen permeability of the above-described barrier layer. Alternatively, in the first aspect, the heat-sealing layer may, for example, satisfy either one of the ranges of water vapor permeability or oxygen permeability of the above-described barrier layer. On the other hand, in the second aspect, the heat-sealing layer may have barrier properties such as water vapor barrier properties and gas barrier properties. In the second aspect, the heat-sealing layer may satisfy at least one or both of the ranges of water vapor permeability and oxygen permeability of the above-described barrier layer. Yes.

[0070] The heat-sealing layer is a layer that melts and adheres by heating, ultrasonic waves, etc. The heat-sealing layer preferably contains a water-dispersible resin. Examples of the water-dispersible resin include those described above as water-suspended polymers other than hydroxy polyurethane, and preferably acrylic resins such as polyolefin resins, styrene / acrylic copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-vinyl acetate copolymers, polyester resins, rubber-based resins, urethane resins, polyamide resins, etc. In addition to these resins, lubricants such as paraffin wax, carnauba wax, and polyolefin wax, and pigments such as silica and kaolin may be added for the purpose of preventing blocking and improving oil resistance. The heat-sealing layer is preferably a layer containing at least one resin selected from the group consisting of styrene / acrylic copolymers and polyolefin resins. Examples of commercially available materials include styrene acrylic aqueous dispersion (product name: XP8829, manufactured by Starlight PMC), polyolefin aqueous dispersion (product name: Rhobarr320, manufactured by Dow), etc.

[0071] The heat-sealing layer is preferably a layer containing at least one resin selected from the group consisting of styrene / acrylic copolymers and polyolefin resins. Examples of commercially available materials include styrene acrylic aqueous dispersion (product name: XP8829, manufactured by Starlight PMC), polyolefin aqueous dispersion (product name: Rhobarr320, manufactured by Dow), etc. When the heat-sealing layer has barrier properties, the water vapor permeability of the heat-sealing layer at 40 °C and 90% RH is, for example, 1 to 100 g / m 2 ·day when converted to a thickness of 20 μm. Also, the oxygen permeability of the heat-sealing layer at 23 °C and 50% RH is, for example, 1 to 100 mL / m 2 ·day·atm when converted to a thickness of 20 μm.

[0072] (Coating amount of heat-sealing layer) The coating amount of the heat-sealing layer is not particularly limited, but from the viewpoint of heat-sealing properties, it is preferably 1 g / m 2 or more, more preferably 2 g / m 2 or more as the solid content after drying. And from the viewpoint of re-dissociation properties, it is preferably 15 g / m 2 or less, more preferably 10 g / m 2 or less, still more preferably 8 g / m 2 or less, and even more preferably 6 g / m 2 or less. The thickness of the heat-sealing layer is preferably 0.5 to 20 μm, and more preferably 1 to 10 μm.

[0073] (Method for forming heat-sealing layer) The method for forming the heat-sealing layer is not particularly limited. For example, a heat-sealing layer coating solution in which a water-dispersible resin is dispersed in a solvent is prepared. It is preferable to coat the obtained heat-sealing layer coating solution on the barrier layer of the paper substrate and dry it to form the heat-sealing layer.

[0074] The solvent for the heat-sealing layer coating solution is not particularly limited, and water or an organic solvent such as ethanol, isopropyl alcohol, methyl ethyl ketone, toluene, etc. can be used. Among these, from the viewpoint of not causing problems with volatile organic solvents, the dispersion medium for the heat-sealing layer coating solution is preferably an aqueous medium, and more preferably water.

[0075] The total coating amount of the barrier layer and the heat-sealing layer is preferably 12 g / m 2is as follows, more preferably 11 g / m 2 is as follows. Being within the above range means that even if the layer is thin, it can exhibit very high gas barrier properties and water vapor barrier properties. Also, being within the above range makes it easier to increase the pulp recovery rate, enables the product to be made lighter, and improves the biodegradation performance. The lower limit of the coating amount is not particularly limited, but is preferably 2 g / m 2 or more, more preferably 5 g / m 2 or more, still more preferably 8 g / m 2 or more.

[0076] When a sample obtained by heat-sealing the heat-sealing layers of the barrier laminate at 150 °C, 0.2 MPa, and for 1 second is peeled off with a tensile tester, the heat-sealing strength is , preferably 2.0 N / 15 mm or more, more preferably 2.5 N / 15 mm or more, still more preferably 2.8 N / 15 mm or more, and even more preferably 3.0 N / 15 mm or more. When the heat-sealing strength is within the above range, it is possible to prevent the bag from bursting when transporting the contents. The upper limit is not particularly limited, but is preferably 10.0 N / 15 mm or less, 7.0 N / 15 mm or less, 5.0 N / 15 mm or less, 4.0 N / 15 mm or less. In the first and second aspects, the barrier laminate may have other layers in addition to the barrier layer and heat-sealing layer described above. In the second aspect, the other layer may have barrier properties such as a water vapor barrier layer and a gas barrier layer.

[0077] <Manufacture of Barrier Laminate> The manufacturing method of the barrier laminate is not particularly limited, and known methods can be adopted. The manufacturing method of the barrier laminate has a step of forming a barrier layer by first coating a barrier layer coating liquid on a paper substrate. If necessary, it may have a step of forming a heat seal layer by coating a heat seal layer coating liquid on the surface of the paper substrate coated with the barrier layer. The formation of each layer is as described above. Each layer may be formed by sequentially coating and drying the coating liquid, or may be dried after simultaneous multilayer coating.

[0078] There is no particular limitation on the drying equipment for drying each coating layer, and known equipment can be used. Examples of the drying equipment include a hot air dryer, an infrared dryer, a gas burner, a hot plate, and the like.

[0079] In the first aspect of the present disclosure, the barrier laminate has a barrier layer on at least one surface of a paper substrate. The barrier laminate preferably has a paper substrate, a barrier layer, and a heat seal layer in this order. The barrier laminate may be a laminate composed only of a paper substrate and a single-layer barrier layer, or may be a laminate composed only of a paper substrate, a single-layer barrier layer, and a heat seal layer.

[0080] Further, the second aspect of the present disclosure is a barrier laminate having a barrier layer on at least one surface of a paper substrate, wherein the barrier layer contains (A) hydroxy polyurethane, (B) swellable layered silicate, and (C) cationic resin, and provides a barrier laminate. According to this aspect, very high water vapor barrier properties and gas barrier properties can be exhibited by hydroxy polyurethane, swellable layered silicate, and cationic resin, and the coating amount of the barrier laminate can be suppressed.

[0081] In a second aspect, the barrier layer containing the above components (A) to (C) exhibits excellent water vapor barrier properties and gas barrier properties even when it is a single layer, but it may have two or more layers. Further, in the second aspect, when further having another layer (for example, a heat seal layer), the other layer may have barrier properties such as a water vapor barrier layer and a gas barrier layer. That is, in the second aspect, the water vapor permeability and the oxygen permeability may include the contribution of other layers in addition to the barrier layer containing the above components (A) to (C).

[0082] The barrier laminate can be suitably used as a packaging material for foods, cosmetics, daily sundries, medical products, electronic components, etc. Since the barrier laminate has extremely high water vapor barrier properties and gas barrier properties, it can also be suitably used as a packaging material for contents having a fragrance or odor. Further, it can also be suitably used as a packaging material for foods, cosmetics, daily sundries, medical products, electronic components, etc. that are exposed to high humidity conditions. The barrier laminate can be suitably used for flexible packaging materials such as wrapping paper, packaging bags, lids, labels, etc.; liquid containers such as milk cartons; packaging containers such as cups, trays, dishes, lid materials, laminated tubes, etc. The contents to be packaged may be liquids, solids (granular substances, powdery substances, etc.), or gel-like substances.

[0083] [Packaging bag] The packaging bag according to another embodiment of the present disclosure is a packaging bag using the above barrier laminate. Examples of the packaging bag include forms such as a standing pouch type, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope sticker seal type, a clamshell sticker seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a corner bottom seal type, and a gusset type. The packaging bag of the present embodiment may be one in which the heat seal layers of the barrier laminate are opposed by bending or overlapping two sheets, and the peripheral edges are heat sealed so as to have the above form. Further, the packaging bag may be one in which the barrier laminate is bent or overlapped, and the peripheral edges are adhered with an adhesive so as to have the above form.

[0084] [Oxygen Permeability at 23°C and 50% RH] Using an oxygen permeability measuring device (OX-TRAN2 / 22 manufactured by MOCON), the oxygen permeability of the barrier laminate was measured under the conditions of a temperature of 23°C and a relative humidity of 50%. Specifically, on the surface of the barrier layer of the barrier laminate, an isocyanate-based adhesive (mixing 1 part of Dick Dry KW-75 with 10 parts of Dick Dry LX-500 manufactured by DIC Corporation) was applied at 5 g / m 2 After application, a CPP film with a thickness of 20 μm (unstretched polypropylene film: GP-32 manufactured by Hokuriku Kasei Co., Ltd.) was laminated to form a laminated sheet. For the laminated sheet, in accordance with JIS K7126-2:2006, the oxygen permeability at a temperature of 23°C and a relative humidity of 50% was measured. The lower the value of the oxygen permeability, the better the oxygen barrier property. Laminating the CPP film is to make it easy to measure without being affected by the unevenness of the laminate, and the CPP film does not affect the oxygen permeability.

[0085] [Oxygen Permeability at 23°C and 85% RH] The oxygen permeability at 23°C and 85% RH was measured in the same manner as the measurement of the oxygen permeability at 23°C and 50% RH above, except that the conditions were changed to a temperature of 23°C and a relative humidity of 85%.

[0086] [Water Vapor Permeability] The water vapor permeability of the barrier laminates obtained in the examples and comparative examples was measured in accordance with JIS-Z-0208:1976 (cup method) Method B (40°C ± 0.5°C, relative humidity 90% ± 2%), with the side having the barrier layer facing inward.

[0087] [Oxygen Permeability of the Barrier Layer at 23°C and 50% RH] The calculation of the oxygen permeability of the barrier layer at 23°C and 50% RH in the barrier laminate can be performed by the following procedure. (When materials of layers other than the barrier layer such as the heat-sealing layer are available) For example, when the barrier laminate has a layer structure of paper substrate / barrier layer / heat-seal layer, it is calculated as follows. The layer structure of the barrier laminate can be analyzed by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. Procedure 1: Measure the oxygen permeability of the barrier laminate. The oxygen permeability of the barrier laminate can be measured by the method described above. Procedure 2: Analyze the thickness of the heat-seal layer. The thickness of the heat-seal layer can be measured by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. The heat-seal layer can be applied to an unstretched polypropylene film or a PET film so as to have the measured thickness of the heat-seal layer, and the oxygen permeability of the heat-seal layer alone can be estimated. Procedure 3: Calculate the oxygen permeability of the barrier layer alone based on the following formula from the oxygen permeability of the barrier laminate in Procedure 1 and the oxygen permeability of the heat-seal layer alone in Procedure 2. At this time, regarding the oxygen permeability of the paper substrate, when glassine paper is not used as the paper substrate (as a guideline, when the total light transmittance of the barrier laminate is less than 60%), it does not need to be considered. 1 / P = 1 / P1 + 1 / P2 + ··· + 1 / P n P: Oxygen permeability of the barrier laminate, P1, P2, ··· P n : Oxygen permeability of each layer

[0088] (When materials of layers other than the barrier layer such as the heat-seal layer cannot be obtained) For example, when the barrier laminate has a layer structure of paper substrate / barrier layer / heat-seal layer, it is calculated as follows. The layer structure of the barrier laminate can be analyzed by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. Procedure 1: Measure the oxygen permeability of the barrier laminate. The oxygen permeability of the barrier laminate can be measured by the method described above. Procedure 2: Analyze the material and thickness of the heat-sealing layer. The material of the heat-sealing layer can be analyzed by pyrolysis GC / MS, FT-IR analysis, Raman spectrum analysis, etc. The thickness of the heat-sealing layer can be measured by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. From the material and thickness of the heat-sealing layer, the oxygen permeability of the heat-sealing layer alone can be extrapolated. Procedure 3: Calculate the oxygen permeability of the barrier layer alone based on the following formula from the oxygen permeability of the barrier laminate in Procedure 1 and the oxygen permeability of the heat-sealing layer alone in Procedure 2. At this time, regarding the oxygen permeability of the paper substrate, when glassine paper is not used as the paper substrate (as a guideline, when the total light transmittance of the barrier laminate is less than 60%), it does not need to be considered. 1 / P = 1 / P1 + 1 / P2 + ··· + 1 / P n P: Oxygen permeability of the barrier laminate, P1, P2, ··· P n : Oxygen permeability of each layer

[0089] [Water vapor permeability of the barrier layer] The calculation of the water vapor permeability of the barrier layer in the barrier laminate at 40 °C and 90% RH can be performed by the following procedure. (When the materials of layers other than the barrier layer such as the heat-sealing layer are available) For example, when the barrier laminate has a layer structure of paper substrate / barrier layer / heat-sealing layer, it is calculated as follows. Note that the layer structure of the barrier laminate can be analyzed by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. (analysis method). Procedure 1: Measure the water vapor permeability of the barrier laminate. The water vapor permeability of the barrier laminate can be measured by the method described above. Procedure 2: Analyze the thickness of the heat-sealing layer. The thickness of the heat-sealing layer can be measured by cross-sectional observation with an electron microscope or X-ray CT measurement, etc. Apply the heat-sealing layer to an unstretched polypropylene film or a PET film so that it has the measured thickness of the heat-sealing layer, and the water vapor permeability of the heat-sealing layer alone can be extrapolated. Step 3: Calculate the water vapor transmission rate of the barrier layer alone based on the following formula from the water vapor transmission rate of the barrier laminate in Step 1 and the water vapor transmission rate of the heat seal layer alone in Step 2. At this time, regarding the oxygen transmission rate of the paper substrate, it is not necessary to consider when glassine paper is not used as the paper substrate (as a guideline, when the total light transmittance of the barrier laminate is less than 60%). 1 / P = 1 / P1 + 1 / P2 + ··· + 1 / Pn P: Water vapor transmission rate of the barrier laminate, P1, P2, ··· Pn: Water vapor transmission rate of each layer

[0090] (When materials for layers other than the barrier layer such as the heat seal layer cannot be obtained) For example, when the barrier laminate has a layer structure of paper substrate / barrier layer / heat seal layer, calculate as follows. Note that the layer structure of the barrier laminate can be analyzed by cross-sectional observation with an electron microscope, X-ray CT measurement, etc. (analysis method). Step 1: Measure the water vapor transmission rate of the barrier laminate. The water vapor transmission rate of the barrier laminate can be measured by the method described above. Step 2: Analyze the material and thickness of the heat seal layer. The material of the heat seal layer can be analyzed by thermal decomposition GC / MS, FT-IR analysis, Raman spectrum analysis, etc. The thickness of the heat seal layer can be measured by cross-sectional observation with an electron microscope, X-ray CT measurement, etc. This can be done. From the material and thickness of the heat seal layer, the water vapor transmission rate of the heat seal layer alone can be estimated. Step 3: Calculate the water vapor transmission rate of the barrier layer alone based on the following formula from the water vapor transmission rate of the barrier laminate in Step 1 and the water vapor transmission rate of the heat seal layer alone in Step 2. At this time, regarding the oxygen transmission rate of the paper substrate, it is not necessary to consider when glassine paper is not used as the paper substrate (as a guideline, when the total light transmittance of the barrier laminate is less than 60%). 1 / P = 1 / P1 + 1 / P2 + ··· + 1 / Pn P: Water vapor transmission rate of the barrier laminate, P1, P2, ··· Pn: Water vapor transmission rate of each layer

[0091] [Evaluation of Redissociability (Pulp Recovery Rate after Redissociation)] A barrier laminate with a dry mass of 30 g was manually torn into 3 - 4 cm squares and immersed in tap water at 20°C overnight. After diluting with tap water so that the concentration of the barrier laminate became 2.5% by mass, it was disintegrated for 20 minutes at a rotational speed of 3000 rpm using a TAPPI standard disintegrator (manufactured by Kumagai Riki Kogyo Co., Ltd.). The obtained pulp slurry was subjected to screening treatment in a water flow of 8.3 L / min using a flat screen (manufactured by Kumagai Riki Kogyo Co., Ltd.) equipped with a 6 - cut (slit width 0.15 mm) screen plate. The undisintegrated matter remaining on the screen plate was collected, dried in an oven at 105°C, and the dry mass was measured. The pulp recovery rate was calculated from the following formula. Pulp recovery rate (%) = {Dry mass of the barrier laminate used in the test (g) - Dry mass of the undisintegrated matter (g)} / Dry mass of the barrier laminate used in the test × 100

[0092] [Measurement of Heat Seal Peel Strength] A pair of two barrier laminates were overlapped with the coating layers facing each other and heat - sealed under the conditions of 150°C, 0.2 MPa, and 1 second using a heat - seal tester (manufactured by Tester Sangyo Co., Ltd., TP - 701 - B). The heat - sealed test piece was left standing in a room at a temperature of 23°C ± 1°C and a humidity of 50% ± 2% for 4 hours or more. Subsequently, the heat - sealed test piece was cut into a width of 15 mm and subjected to T - peel using a tensile tester (Tensilon universal material tester RTC - 1250A, manufactured by A&D Company) at a tensile speed of 300 mm / min, and the maximum load recorded was taken as the heat - seal peel strength (N / 15 mm).

Example

[0093] Examples are given below to specifically explain the present invention, but the present invention is not limited to these examples. Unless otherwise specified, the following operations were carried out under the conditions of 25°C and a relative humidity of 50%RH. Also, in the examples and comparative examples, "parts" and "%" indicate "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0094] (Example 1) To 33.3 parts by mass of an aqueous dispersion of a layered inorganic compound (swelling mica (sodium tetrasilicate mica), average length 6.3 μm, aspect ratio approximately 1000, thickness approximately 5 nm, solid content concentration 6% by mass, product name: NTO-05, manufactured by Toppan Industries), while stirring, 6.8 parts by mass of a self-emulsifying emulsion of an ethylene·acrylic acid copolymer (solid content concentration 29.2% by mass, product name: Zexcen AC, manufactured by Sumitomo Seika Chemicals) was added. Further, 26.7 parts by mass of a self-emulsifying aqueous emulsion of hydroxy polyurethane (hydroxyl value: 235 mgKOH / g, solid content concentration 30% by mass, product name: HPU-W013A, manufactured by Dainichi Seika Kogyo) was added, and the mixture was stirred. To this, 0.57 part by mass of a modified polyamide-based resin (surface charge 0.4 meq / g, solid content concentration 53% by mass, product name: SPI203(50)H, manufactured by Tago Chemical Industry) as a cationic resin was added, and the mixture was stirred. Further, 0.30 part by mass of a 25% aqueous ammonia solution was added and stirred. Further, diluting water was added to make the solid content concentration 19% by mass, obtaining a barrier layer coating liquid. The above barrier layer coating liquid was applied to one surface of a paper base material 50 g / m 2 (one-sided glossy kraft paper, manufactured by Oji Efftex) so as to be 5 g / m in terms of solid content, 2 dried at 120°C for 1 minute, and a barrier layer was formed. Further, as a heat seal layer coating liquid, a styrene acrylic aqueous dispersion (solid content concentration 48% by mass, product name: XP8829, manufactured by Starlight PMC) was diluted with water to a solid content concentration of 22% by mass, and applied so as to be 5 g / m in terms of solid content, 2 dried at 120°C for 1 minute, and a heat seal layer was formed, obtaining a heat-sealable barrier laminate. For drying each layer, a hot air dryer was used. The oxygen permeability of the heat seal layer at 23°C and 50% RH exceeds 10.0 mL / m 2 ·day·atm and does not correspond to the barrier layer in the first aspect.

[0095] (Example 2) An ethylene-acrylic acid copolymer self-emulsifying emulsion of the barrier layer coating liquid was used in an amount of 13.7 parts by mass, and a self-emulsifying aqueous emulsion of hydroxy polyurethane was used in an amount of 20.0 parts by mass. Otherwise, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0096] (Example 3) An expandable mica of the barrier layer coating liquid was used in an amount of 50 parts by mass. Otherwise, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0097] (Example 4) The paper substrate was kraft paper 70 g / m 2 (OK kraft, manufactured by Oji Materia Co., Ltd.). Otherwise, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0098] (Example 5) The self-emulsifying emulsion of the ethylene-acrylic acid copolymer was changed to 5.1 parts by mass of a styrene-acrylic copolymer binder (solid content concentration: 39% by mass, product name: JONCRYL HSL-9012, manufactured by BASF). Otherwise, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0099] (Example 6) The self-emulsifying emulsion of the ethylene-acrylic acid copolymer was changed to 4.3 parts by mass of an acid-modified styrene-butadiene copolymer binder (solid content concentration: 46% by mass, product name: LX407S12, manufactured by Nippon Zeon Co., Ltd.). Otherwise, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0100] (Example 7) An ethylene-acrylic acid copolymer self-emulsifying emulsion was changed to 8.7 parts by mass of a polyolefin resin binder (solid content concentration: 23% by mass, product name: HYDRECT HS, manufactured by DIC Corporation). Except for the above change, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0101] (Example 8) Except for changing the cationic resin in the barrier layer coating liquid to 1.90 parts by mass, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0102] (Example 9) An ethylene-acrylic acid copolymer self-emulsifying emulsion was changed to 20.0 parts by mass of an aqueous solution in which polyvinyl alcohol (product name: EXCEVAL HR-3010, manufactured by Kuraray Co., Ltd.) was dissolved in water so that the solid content concentration became 10% by mass. Except for the above change, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0103] (Example 10) Except for changing the heat-sealing layer coating liquid to a polyolefin aqueous dispersion (solid content concentration: 43% by mass, product name: Rhobarr 320, manufactured by Dow), in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate. The heat-sealing layer has a water vapor transmission rate of 50 g / m 2 ·day or more at 40°C and 90% RH, and an oxygen transmission rate of more than 10.0 mL / m 2 ·day·atm at 23°C and 50% RH, and does not correspond to the barrier layer in the first aspect.

[0104] (Example 11) The self-emulsifying emulsion of ethylene-acrylic acid copolymer was changed to 40.0 parts by mass of an aqueous solution adjusted to a solid content concentration of 5% by mass from an aqueous ammonium polyacrylate solution (solid content concentration: 30% by mass, product name: Aron A-30, manufactured by Toagosei Co., Ltd.). Otherwise, in the same manner as in Example 1, a barrier layer and a heat-seal layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0105] (Example 12) The addition amount of the self-emulsifying emulsion of ethylene-acrylic acid copolymer was changed to 3.4 parts by mass, and further 10.0 parts by mass of an aqueous polyvinyl alcohol solution in which polyvinyl alcohol (product name: EXCEVAL HR-3010, manufactured by Kuraray Co., Ltd.) was dissolved in water so as to have a solid content concentration of 10% by mass was added to the barrier layer coating liquid. Otherwise, in the same manner as in Example 10, a barrier layer and a heat-seal layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0106] (Example 13) The self-emulsifying emulsion of hydroxypolyurethane in the barrier layer coating liquid was 31.7 parts by mass, the self-emulsifying aqueous emulsion of ethylene-acrylic acid copolymer was 1.7 parts by mass, and the cationic resin was 1.90 parts by mass. The coating amount of the heat-seal layer was changed to 3 g / m 2 (in terms of solid content). Otherwise, in the same manner as in Example 10, a barrier layer and a heat-seal layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0107] (Example 14) Except that the heat-seal layer coating liquid was not applied, in the same manner as in Example 1, a barrier layer was formed on a paper substrate to obtain a barrier laminate.

[0108] (Example 15) The swelling mica in the barrier layer coating liquid was 83.3 parts by mass, the cationic resin was 5.7 parts by mass, and the coating amount of the heat-seal layer was 3 g / m 2Except for changing to (solid content conversion), in the same manner as in Example 10, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0109] (Example 16) The addition amount of the self-emulsifying emulsion of ethylene-acrylic acid copolymer was changed to 5.1 parts by mass, and further 5.0 parts by mass of an aqueous polyvinyl alcohol solution in which polyvinyl alcohol (product name: EXCEVAL RS-1717, manufactured by Kuraray Co., Ltd.) was dissolved in water so that the solid content concentration was 10% by mass was added to the barrier layer coating liquid, and the coating amount of the heat-sealing layer was 3 g / m 2 Except for changing to (solid content conversion), in the same manner as in Example 10, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0110] (Comparative Example 1) Except that the self-emulsifying emulsion of ethylene-acrylic acid copolymer in the barrier layer coating liquid was 34.2 parts by mass and the self-emulsifying aqueous emulsion of hydroxy polyurethane was 0 part by mass, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0111] (Comparative Example 2) Except that the swelling mica in the barrier layer coating liquid was 0 part by mass and the cationic resin was 0 part by mass, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0112] (Comparative Example 3) Except that the cationic resin in the barrier layer coating liquid was 0 part by mass, in the same manner as in Example 1, a barrier layer and a heat-sealing layer were formed on a paper substrate to obtain a heat-sealable barrier laminate.

[0113] (Comparative Example 4) A barrier layer and a heat-sealing layer were formed on a paper substrate in the same manner as in Example 1, except that the cationic resin in the barrier layer coating liquid was 18.9 parts by mass, to obtain a heat-sealable barrier laminate.

[0114] (Comparative Example 5) A barrier layer and a heat-sealing layer were formed on a paper substrate in the same manner as in Example 1, except that the swelling mica in the barrier layer coating liquid was changed to 2 parts by mass of kaolin (engineered kaolin, average length 0.89 μm, aspect ratio of about 33, thickness of about 27 nm, solid content concentration 100% by mass, product name: Contzer Extreme, manufactured by Imerys), to obtain a heat-sealable barrier laminate. Thereby, a barrier layer and a heat-sealing layer were formed on the paper substrate to obtain a heat-sealable barrier laminate.

[0115] (Comparative Example 6) A barrier layer and a heat-sealing layer were formed on a paper substrate in the same manner as in Example 1, except that the self-emulsifying aqueous emulsion of hydroxypolyurethane in the barrier layer coating liquid was changed to 80.0 parts by mass of an aqueous polyvinyl alcohol solution in which polyvinyl alcohol (product name: EXCEVAL AQ-4104, manufactured by Kuraray) was dissolved in water so that the solid content concentration was 10% by mass, to obtain a heat-sealable barrier laminate.

[0116] [Sealability] The paper laminates of the examples and comparative examples were each formed into a pillow-shaped packaging bag and heat-sealed to produce a packaging bag. One side of the obtained packaging bag was cut, and a heat-sealing checker (product name: Ageless Seal Check, manufactured by Mitsubishi Gas Chemical Company, components: high-boiling ester, high-boiling hydrocarbon, vegetable oil, azo-based oil-soluble dye) was dropped into the packaging bag to evaluate the presence or absence of liquid leakage at the seal portion. A: The heat-sealing checker liquid does not leak and is sealed. B: The heat-sealing checker liquid leaks, pinholes occur, and it does not adhere.

[0117] The formulations (ratios of parts by mass of solids), physical properties, evaluation results, oxygen permeability and water vapor permeability of the barrier layer itself, and the content ratios (mass %) of each material in the barrier layer of each obtained barrier laminate are shown in Tables 1 to 3. In the table, the unit of the coating amount is g / m 2 and the unit of the oxygen permeability is mL / m 2 ·day·atm, and the unit of the water vapor permeability (measured under the conditions of 40 °C and 90% RH) is g / m 2 ·day and the unit of the heat seal strength is N / 15 mm. The re-dissociability is the pulp recovery rate (mass %) after the barrier laminate is re-dissociated. In the table, the oxygen permeability of the barrier layer is the oxygen permeability of the barrier layer at 23 °C and 50% RH, and the water vapor permeability of the barrier layer indicates the water vapor permeability of the barrier layer at 40 °C and 90% RH. In the table, regarding the content in the barrier layer, "aqueous suspension polymers, etc." indicates the total content ratio of aqueous suspension polymers other than hydroxy polyurethane and water-soluble polymers other than hydroxy polyurethane.

[0118] [Oxygen Permeability of the Barrier Layer at 23 °C and 50% RH] Using an oxygen permeability measuring device (OX-TRAN2 / 22 manufactured by MOCON), the oxygen permeability of the barrier layer alone was measured under the conditions of a temperature of 23 °C and a relative humidity of 50%. Specifically, on a paper substrate (one-sided bleached kraft paper, basis weight 50 g / m 2 , manufactured by Oji Efftex Co., Ltd.), the barrier layer coating liquid was coated according to the formulations and coating amounts of each example and comparative example, and dried at 120 °C for 1 minute to form a barrier layer. Further, on the surface of the paper substrate on the barrier layer side, an isocyanate-based adhesive (manufactured by DIC Corporation, a mixture of 10 parts of Dick Dry LX-500 and 1 part of Dick Dry KW-75) was applied at 5 g / m 2 After coating, a 20-μm-thick CPP film (unstretched polypropylene film: manufactured by Kitakoshi Kasei Co., Ltd., GP-32) was laminated to form a laminated sheet. For the laminated sheet, the oxygen permeability at a temperature of 23°C and a relative humidity of 50% was measured in accordance with JIS K7126-2:2006. The lower the value of the oxygen permeability, the better the oxygen barrier property. Note that the CPP film is laminated to make it easy to measure without being affected by the unevenness of the laminate, and the CPP film does not affect the oxygen permeability.

[0119] [Water vapor permeability of the barrier layer] The water vapor permeability was measured by applying the barrier layer coating liquid to a paper substrate (one-sided bleached kraft paper, basis weight 50 g / m 2 , manufactured by Oji Eftex Co., Ltd.) according to the formulation and coating amount of each example and comparative example, drying at 120°C for 1 minute to form a barrier layer, and then measuring in accordance with JIS-Z-0208:1976 (cup method) Method B (40°C ± 0.5°C, relative humidity 90% ± 2%) with the side with the barrier layer facing inward.

[0120]

Table 1

[0121]

Table 2

[0122]

Table 3

Claims

1. A barrier laminate having a barrier layer on at least one surface of a paper substrate, wherein the barrier layer contains a hydroxypolyurethane, a swellable layered silicate, and a cationic resin, the content ratio of the hydroxypolyurethane in the barrier layer is 40.0 to 70.0% by mass, and the content ratio of the swellable layered silicate in the barrier layer is 10.0 to 25.0% by mass.

2. The barrier laminate according to claim 1, wherein the content ratio of the cationic resin in the barrier layer is 1.0 to 20.0% by mass.

3. The barrier layer further contains at least one selected from the group consisting of a water-suspensible polymer other than the hydroxypolyurethane and a water-soluble polymer other than the hydroxypolyurethane, the water-suspensible polymer other than the hydroxypolyurethane contains at least one selected from the group consisting of a styrene-butadiene copolymer, an acrylic resin, an olefin-unsaturated carboxylic acid copolymer, and a polyolefin resin, and the water-soluble polymer other than the hydroxypolyurethane contains at least one selected from the group consisting of a vinyl alcohol-based polymer, a (meth)acrylic acid-based polymer, polyethylene glycol, a water-soluble polyamide, polyacrylamide, a polyamine, a polycarboxylic acid, and a water-soluble cellulose derivative.

4. The barrier laminate further has a heat-sealing layer on the side where the barrier layer is laminated, and the heat-sealing strength when a sample obtained by heat-sealing the heat-sealing layers of the barrier laminate at 150°C, 0.2 MPa, and for 1 second is peeled off using a tensile tester is 2.0 N / 15 mm or more.

5. The total coating amount of the barrier layer and the heat-sealing layer is 12 g / m ２ The barrier laminate according to claim 4, wherein the total coating amount is 12 g / m or less.

6. When a CPP film is laminated to the barrier laminate, the oxygen permeability at 23°C and 85% RH is 10.0 mL / m ２ ・day・atm or less. The barrier laminate according to claim 1.

7. The barrier laminate according to claim 1, wherein the recovery rate of the pulp after redissolving the barrier laminate is 85% by mass or more.

8. A packaging bag made using the barrier laminate according to any one of claims 1 to 7.

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