laminated body

Abstract

The present invention provides a laminate having low air permeability and excellent moisture permeability in a low-temperature, low-humidity environment. The laminate comprises: a porous substrate; and a moisture-permeable membrane provided on one surface of the porous substrate. The laminate has an air barrier of 3000 sec / 100 cc or higher according to the Gurley method in accordance with JIS P8117-2009, and a first moisture permeability of 300 g / (m2) under the conditions of a temperature of 5°C, a relative humidity of 45%, and a wind speed of 0.2 m / s or less according to the moisture permeability test method (cup method) in accordance with JIS Z0208-1976. 2 ·24h) or more.

Description

Technical Field

[0001] The present disclosure relates to a laminate. More specifically, the laminate comprises a porous substrate and a moisture-permeable membrane disposed on at least one surface of the porous substrate. This application claims priority to Japanese Patent Application No. 2020-061736, filed in Japan on March 31, 2020, the contents of which are incorporated herein by reference. Background Art

[0002] Conventionally, as a device capable of ventilating without impairing the cooling or heating effect, a heat exchange type ventilator that performs heat exchange between intake air and exhaust air during ventilation is known.

[0003] Heat exchange fins are used in heat exchange ventilation systems to perform heat exchange. These fins physically separate the incoming and outgoing air, requiring low air permeability (gas barrier properties) to prevent mixing of the incoming and outgoing air, and high heat conductivity to facilitate heat exchange between the incoming and outgoing air. Furthermore, since humidity (latent heat) is exchanged between the incoming and outgoing air along with temperature (sensible heat), the heat exchange fins used in total heat exchangers (total heat exchange fins) are also required to have high moisture permeability.

[0004] Heat exchange sheets used in total heat exchangers, for example, can be formed from moisture-permeable membranes made from deliquescent low-molecular-weight compounds such as calcium chloride, lithium chloride, sulfuric acid, and sodium hydroxide. Moisture-permeable membranes made from calcium chloride and lithium chloride are widely used for safety reasons. However, moisture-permeable membranes made from deliquescent and low-molecular-weight compounds have high solubility in water and poor water resistance.

[0005] As a heat exchange plate for a total heat exchanger, a partition member for a total heat exchange plate is also known (see patent document 1), which comprises: a porous substrate; and a hydrophilic polymer compound, which is present on the surface and inside of the porous substrate, and the above-mentioned hydrophilic polymer compound is a polymer of a compound having a quaternary ammonium group and an amide group.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-55683 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, the hydrophilic polymer compound using a polymer of a compound having a quaternary ammonium group and an amide group described in Patent Document 1 has insufficient moisture permeability, particularly insufficient moisture permeability under low-temperature and low-humidity environments.

[0011] Therefore, an object of the present disclosure is to provide a laminate having low air permeability and excellent moisture permeability.

[0012] Technical Solution

[0013] The inventors of the present disclosure have conducted intensive research to achieve the above-mentioned objectives and have discovered a laminate having low air permeability and excellent moisture permeability. The laminate comprises: a porous substrate; and a moisture-permeable film disposed on one surface of the porous substrate, wherein the gas barrier and moisture permeability under specific conditions of the laminate are both at least specific values. The present disclosure relates to a material completed based on these findings.

[0014] The present disclosure provides a laminate comprising: a porous substrate; and a moisture-permeable film provided on one surface of the porous substrate, wherein the laminate has an air barrier of 3000 sec / 100 cc or more according to the Gurley method of JIS P8117-2009, and a first moisture permeability of 300 g / (m2) under the conditions of a temperature of 5° C., a relative humidity of 45%, and a wind speed of 0.2 m / s or less according to the moisture permeability test method (cup method) of JIS Z0208-1976. 2 ·24h) or more.

[0015] In the above-mentioned laminate, it is preferred that, with respect to the first moisture permeability and the second moisture permeability under the conditions of a temperature of 20°C, a relative humidity of 65%, and a wind speed of 0.2 m / s or less in accordance with the moisture permeability test method (cup method) of JIS Z0208-1976, when a linear function obtained by connecting two points of the first moisture permeability and the second moisture permeability under the moisture permeability measurement conditions in a graph where the volume absolute humidity under the moisture permeability measurement conditions is represented by x and the moisture permeability is represented by y, the equation y = ax + b satisfies a ≥ 154 and b ≥ -170.

[0016] Effects of the Invention

[0017] The laminate disclosed herein has low air permeability and excellent moisture permeability. Furthermore, it exhibits excellent moisture permeability even in low-temperature and low-humidity environments. Therefore, the laminate disclosed herein can be particularly preferably used as a total heat exchange sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional view showing one embodiment of the laminated body of the present disclosure.

[0019] Figure 2 This is a linear function graph plotting the moisture permeability of the laminates obtained in Examples and Comparative Examples, with the volume absolute humidity on the x-axis and the moisture permeability on the y-axis. DETAILED DESCRIPTION

[0020] A laminate according to one embodiment of the present disclosure comprises at least: a porous substrate; and a moisture-permeable membrane disposed on at least one surface of the porous substrate. The moisture-permeable membrane may be disposed on one or both surfaces of the porous substrate. Furthermore, the laminate may have a structure in which the moisture-permeable membrane sandwiches two porous substrates. In other words, the porous substrates may be disposed on both surfaces of the moisture-permeable membrane. In this case, the two porous substrates may be the same porous substrate or may differ in material, thickness, etc.

[0021] Figure 1 1 is a schematic cross-sectional view showing one embodiment of the laminate of the present disclosure. The laminate 1 includes a porous substrate 11 and a moisture-permeable membrane 12 provided on one surface 11 a of the porous substrate 11 .

[0022] The laminate has an air barrier of 3000 sec / 100 cc or greater, preferably 4000 sec / 100 cc or greater, and more preferably 5000 sec / 100 cc or greater, as measured by the Gurley method according to JIS P8117-2009. The laminate has an air barrier of 3000 sec / 100 cc or greater, thereby exhibiting low air permeability. The upper limit of the air barrier is not particularly limited, and may be, for example, 150,000 sec / 100 cc, 100,000 sec / 100 cc, or 80,000 sec / 100 cc.

[0023] The moisture permeability of the laminate under the conditions of a temperature of 5°C, a relative humidity of 45%, and a wind speed of 0.2 m / s or less (sometimes referred to as "first moisture permeability") according to the moisture permeability test method (cup method) of JIS Z0208-1976 is 300 g / (m 2 ·24h) or more, preferably 400g / (m 2 ·24h) or more, more preferably 500g / (m 2 · 24h) or more. The moisture permeability of the laminate is 300g / (m 2 · 24h) or more, thereby achieving excellent moisture permeability (especially moisture permeability in low temperature and low humidity environments). The upper limit of the first moisture permeability is not particularly limited, and can be, for example, 5000 g / (m 2 ·24h)、2000g / (m 2 ·24h)、1000g / (m 2 ·24h).

[0024] The moisture-permeable membrane is preferably formed from a resin. From the perspective of excellent moisture permeability, the resin preferably has a hydrophilic group. As the hydrophilic group, from the perspective of excellent hydrophilicity, it is preferred to have a cationic group and an anionic group, and more preferably a phosphorylcholine group.

[0025] In addition, from the viewpoint of excellent water resistance, the resin preferably further has a hydrophobic group. As the hydrophobic group, a hydrocarbon group having 2 or more carbon atoms is preferred. As the hydrocarbon group having 2 or more carbon atoms, for example, R in the structural unit represented by the formula (2) described below can be cited. 6 Materials shown and described.

[0026] The resin forming the moisture-permeable film is particularly preferably a copolymer containing a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2).

[0027] [Chemical Formula 1]

[0028]

[0029] [In formula (1), R 1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 2 、R 3 and R 4 are the same or different and represent an alkyl group having 1 to 4 carbon atoms. X represents a divalent hydrocarbon group having 1 to 4 carbon atoms. Y represents a divalent linear hydrocarbon group having 1 to 4 carbon atoms.

[0030] [Chemical Formula 2]

[0031]

[0032] [In formula (2), R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 6 represents a hydrocarbon group having 2 or more carbon atoms]

[0033] In formula (1), R 1 It represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group, more preferably a methyl group.

[0034] In formula (1), R 2 、R 3 and R 4 are the same or different and represent an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, propyl, butyl, and tert-butyl. Among them, methyl is preferred.

[0035] In formula (1), X represents a divalent hydrocarbon group having 1 to 4 carbon atoms, and examples thereof include alkylene, alkenylene, and alkynylene. Examples of alkylene include linear or branched C groups such as methylene, dimethylene, trimethylene, isopropylidene, and tetramethylene. 1-4Examples of the alkenylene group include linear or branched C groups such as vinylene, 1-propenylene, isopropenylene, 1-butenylene, 2-butenylene, and 3-butenylene. 2-4 Among these divalent hydrocarbon groups, linear or branched alkylene groups are preferred, and linear alkylene groups are more preferred.

[0036] In formula (1), Y represents a divalent linear hydrocarbon group having 1 to 4 carbon atoms, examples of which include an alkylene group, an alkenylene group, and an alkynylene group. Examples of the alkylene group include a methylene group, a dimethylene group, a trimethylene group, and a tetramethylene group. Examples of the alkenylene group include a vinylene group, a 1-propenylene group, and a 1-butenylene group. Among these divalent linear hydrocarbon groups, an alkylene group is preferred, and a dimethylene group is more preferred.

[0037] Examples of the monomer that forms the structural unit represented by the above formula (1) include 2-methacryloyloxyethyl phosphorylcholine and the like.

[0038] In formula (2), R 5 It represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group, more preferably a methyl group.

[0039] In formula (2), R 6 represents a hydrocarbon group having at least 2 carbon atoms. From the viewpoint of achieving more appropriate hydrophobicity of the hydrophobic portion, the number of carbon atoms is preferably 4 to 26, more preferably 8 to 22, further preferably 10 to 20, and particularly preferably 14 to 18.

[0040] Examples of the hydrocarbon group having 2 or more carbon atoms include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which two or more of these are bonded together.

[0041] Examples of the aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups. Examples of alkyl groups include linear or branched alkyl groups such as ethyl, propyl, isopropyl, butyl, hexyl, octyl, isooctyl, decyl, dodecyl, and stearyl groups. Examples of alkenyl groups include linear or branched alkenyl groups such as vinyl, allyl, methallyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, and 5-hexenyl groups. Examples of alkynyl groups include linear or branched alkynyl groups such as ethynyl and propynyl groups.

[0042] Examples of the alicyclic hydrocarbon group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclododecyl. 3-12 Cycloalkyl; cyclohexenyl, etc. 3-12 Cycloalkenyl; bicycloheptyl, bicycloheptenyl, etc. 4-15Bridged hydrocarbon groups, etc.

[0043] Examples of the aromatic hydrocarbon group include C groups such as phenyl and naphthyl. 6-14 Aryl (especially C 6-10 Aryl) etc.

[0044] As the hydrocarbon group having 2 or more carbon atoms, an aliphatic hydrocarbon group is preferred, a linear or branched alkyl group is more preferred, and a linear alkyl group is further preferred.

[0045] Examples of the monomer that forms the structural unit represented by the above formula (2) include stearyl (meth)acrylate and the like.

[0046] The structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) may each be present in only one type or in two or more types.

[0047] The molar ratio of the structural unit represented by the above formula (1) to the structural unit represented by the above formula (2) [former / latter] is not particularly limited, but is preferably 1 / 100 to 100 / 1 (i.e., 0.01 to 100.0), more preferably 0.01 to 90, further preferably 0.02 to 80, further preferably 0.1 to 20, and particularly preferably 0.5 to 5.

[0048] The molar ratio of the hydrophilic portion to the hydrophobic portion in the copolymer is preferably 0.01 to 2.0, more preferably 0.01 to 1.5, and even more preferably 0.01 to 1.3. Regarding the hydrophilic portion and the hydrophobic portion, in an energy histogram of a solute-solvent pair obtained by calculating free energy based on an energy representation method, when the negative integral value is defined as an attractive force against water and the positive integral value as a repulsive force against water, the term representing the attractive force is defined as the hydrophilic portion, and the term representing the repulsive force is defined as the hydrophobic portion.

[0049] In the above copolymer, the copolymerization form of the structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) is not particularly limited, and can be any of block copolymerization, alternating copolymerization, and random copolymerization. In the case where the above copolymer is a copolymer of a monomer forming the structural unit represented by the above formula (1) and a monomer forming the structural unit represented by the above formula (2), the above copolymer can be any of block copolymer, alternating copolymer, and random copolymer. Among them, the above copolymer is preferably a random copolymer.

[0050] The copolymer may also have structural units derived from other monomers in addition to the structural units represented by the above formula (1) and the structural units represented by the above formula (2). However, the total molar number of the structural units represented by the above formula (1) and the structural units represented by the above formula (2) in the copolymer is preferably 50 mol% or more, more preferably 90 mol%, and even more preferably 99 mol% or more, relative to the total molar number of the structural units derived from all monomers constituting the copolymer.

[0051] The weight average molecular weight of the copolymer is not particularly limited, but is preferably 20,000 to 2,000,000, more preferably 30,000 to 1,500,000, further preferably 50,000 to 1,200,000, and particularly preferably 70,000 to 500,000. The weight average molecular weight is a value calculated based on polystyrene conversion as measured by gel permeation chromatography (GPC).

[0052] The copolymer comprises a zwitterionic and highly hydrophilic group by including the structural unit represented by the above formula (1), and has a hydrophilic portion. In addition, the copolymer comprises an alkyl ester portion having a carbon number of 2 or more as a hydrophobic portion by including the structural unit represented by the above formula (2). Moreover, when the molar ratio of the structural unit represented by the above formula (1) to the structural unit represented by the above formula (2) is within the above range, the hydrophilic portion and the hydrophobic portion exist in a well-balanced manner in the copolymer. In this case, it can be inferred that a structure in which the hydrophilic portion and the hydrophobic portion are separated can be formed in the moisture permeable film formed by the copolymer, and the hydrophilic portion functions as a water-conducting channel to allow more water vapor to pass through, resulting in excellent moisture permeability.

[0053] Furthermore, while moisture-permeable films formed from calcium chloride and potassium chloride typically tend to experience a significant decrease in water absorption and poor moisture permeability in low-temperature, low-humidity environments, the moisture-permeable film formed from the copolymer described above exhibits excellent moisture permeability, even in low-temperature, low-humidity environments, despite the significant decrease in water absorption. Furthermore, when the molar ratio of the hydrophilic and hydrophobic portions is increased, a moisture-permeable film can be produced that is both highly permeable and less soluble in water, resulting in excellent water resistance. Furthermore, the aqueous solution of the copolymer has a weakly acidic pH, making it less susceptible to metal corrosion (i.e., exhibiting excellent metal corrosion resistance) compared to conventional moisture-permeable films using strongly acidic resins containing acidic functional groups such as sulfonyl groups.

[0054] The moisture-permeable film formed of the above-mentioned resin may contain other components besides the above-mentioned resin within a range not impairing the effects of the above-mentioned laminate.

[0055] The thickness of the moisture-permeable film is not particularly limited, but is preferably 50 nm to 1000 nm, more preferably 100 nm to 500 nm. A thickness of 50 nm or greater improves film-forming properties, leading to improved gas barrier properties. A thickness of 1000 nm or less improves moisture permeability. Furthermore, the moisture-permeable film can be easily formed into a thin film of 1000 nm or less, resulting in excellent economic efficiency.

[0056] It is preferred that the porous substrate is an element that serves as a support for the moisture-permeable membrane and has excellent moisture permeability.

[0057] The material forming the porous substrate may be either a hydrophilic material or a hydrophobic material, but is preferably a hydrophobic material. When a hydrophobic material is used, the aqueous composition for forming a moisture-permeable film does not penetrate the porous substrate when applied thereto. Therefore, a guide substrate is not required in the porous substrate to prevent the aqueous composition from flowing down the surface opposite to the coating film-forming surface.

[0058] Examples of materials for forming the porous substrate include polyolefin resins, cellulose resins, polycarbonate resins, polyamide resins, polyimide resins, polyamide-imide resins, fluorine-based resins, inorganic materials such as metals, glass, and ceramics, and paper. Polyolefin resins are preferred because the moisture-permeable film can be formed on the porous substrate at relatively low temperatures and because they offer excellent moisture permeability and water resistance. The material may also be in a fibrous form, such as metal fiber or inorganic fiber. The porous substrate may be formed of a single material or of two or more materials.

[0059] Examples of the porous substrate include a resin porous film, an inorganic porous film, a metal porous film, and a fibrous substrate.

[0060] The polyolefin resin is a polymer (including olefin elastomers) composed of an olefin as an essential monomer component, that is, a polymer containing at least a structural unit derived from an olefin in the molecule (one molecule). The olefin is not particularly limited, and examples thereof include α-olefins such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene.

[0061] Examples of the polyolefin resin include polymers containing ethylene as an essential monomer component (polyethylene resins), polymers containing propylene as an essential monomer component (polypropylene resins), ionomers, and amorphous cyclic olefin polymers. Among them, polypropylene resins are preferred.

[0062] The porosity of the porous substrate is not particularly limited, but is preferably 30% to 90% by volume, more preferably 40% to 70% by volume. When the porosity is 30% by volume or greater, moisture permeability is improved. When the porosity is 90% by volume or less, the support performance of the moisture-permeable membrane is improved.

[0063] The thickness of the porous substrate is not particularly limited, but is preferably 5 μm or greater, more preferably 10 μm or greater, from the perspective of sufficient support for the moisture-permeable membrane. Furthermore, from the perspective of excellent moisture permeability and economic efficiency, the thickness of the porous substrate is preferably 50 μm or less, more preferably 30 μm or less.

[0064] From the viewpoint of being able to easily form the moisture-permeable film, it is preferred that the surface of the porous substrate on the side having the moisture-permeable film (for example, Figure 1 The surface 11a shown in FIG. 1 is subjected to a hydrophilization treatment. In particular, when a hydrophobic material is used as the material for forming the above-mentioned porous substrate, it is preferred to implement the above-mentioned hydrophilization treatment. Examples of the above-mentioned hydrophilization treatment include corona discharge treatment and plasma treatment. Through these hydrophilization treatments, carboxyl groups, hydroxyl groups or carbonyl groups can be generated on the surface of the porous substrate, and the aqueous composition for forming the above-mentioned moisture permeable film easily wets and spreads on the surface of the porous substrate, easily forming the above-mentioned moisture permeable film. In addition, thus, the adhesion between the above-mentioned porous substrate and the above-mentioned moisture permeable film is improved. In addition, when the above-mentioned porous substrate formed by the hydrophobic substrate is stored as a wound body, although one face of the above-mentioned porous substrate contacts the other face in the wound body, adhesion can be prevented because one hydrophilic face contacts the other hydrophobic face.

[0065] The surface tension of the porous substrate on the side where the moisture-permeable membrane is to be formed is preferably 35 dyn / cm to 55 dyn / cm, more preferably 37 dyn / cm to 50 dyn / cm. When the surface tension is 35 dyn / cm or greater, the aqueous composition for forming the moisture-permeable membrane is easily applied, and the membrane is easily formed. When the surface tension is 55 dyn / cm or less, the aqueous composition for forming the moisture-permeable membrane does not excessively wet and spread, and the membrane is easily formed on the surface of the porous substrate. It should be noted that when the surface of the porous substrate is hydrophilized, the surface on which the moisture-permeable membrane is to be formed is the surface subjected to the hydrophilization treatment.

[0066] The surface tension of the interior of the porous substrate (i.e., the interior of the region where the moisture-permeable film is not formed) is preferably less than 35 dyn / cm, more preferably 33 dyn / cm or less. When the surface tension is less than 35 dyn / cm, the aqueous composition used to form the moisture-permeable film is prevented from penetrating into the interior of the porous substrate, facilitating the formation of the moisture-permeable film on the surface of the porous substrate. It should be noted that, when the surface of the porous substrate has been hydrophilized, the interior of the porous substrate refers to the interior of the region where the hydrophilization treatment has not been performed. Furthermore, the surface tension of the interior can be determined by measuring a cross-section of the porous substrate.

[0067] The moisture permeability of the laminate under the conditions of a temperature of 20°C, a relative humidity of 65%, and a wind speed of 0.2 m / s or less (sometimes referred to as "second moisture permeability") according to the moisture permeability test method (cup method) of JIS Z0208-1976 is preferably 1600 g / (m 2 ·24h) or more, more preferably 1700g / (m 2 ·24h) or more, more preferably 1800g / (m 2 The above laminate has excellent moisture permeability, so the above moisture permeability can be 1600g / (m 2 · 24h) or more.

[0068] In the above-mentioned laminate, it is preferred that, with respect to the first moisture permeability and the second moisture permeability, in a graph where the volume absolute humidity under moisture permeability measurement conditions is x and the moisture permeability is y, a linear function obtained by connecting two points of the first moisture permeability and the second moisture permeability is expressed by the equation y = ax + b, such that a ≥ 154 and b ≥ -170 are satisfied. It should be noted that the volume absolute humidity x under the first moisture permeability is approximately 3.1 g / m 3 The volume absolute humidity x at the second moisture permeability is about 11.2g / m 3 .

[0069] In the above equation, a is 154 or greater, preferably 155 or greater, more preferably 160 or greater, and even more preferably 180 or greater. As the absolute humidity increases, the vapor pressure increases. Therefore, generally speaking, as the absolute humidity increases, the moisture permeability increases. Therefore, the above-described laminate can achieve a ≥ 154, which is difficult to achieve with conventional laminates including a moisture-permeable film, and in this case, the moisture permeability is particularly excellent.

[0070] In the above equation, b is -170 or greater, preferably -150 or greater, more preferably -130 or greater, and even more preferably -110 or greater. When b ≥ -170 is satisfied, moisture permeability is particularly excellent in low-temperature, low-humidity environments. Furthermore, when a ≥ 154 and b ≥ -170 are satisfied, moisture permeability is excellent in a wide range of environments, including low-temperature, low-humidity environments and normal temperature environments.

[0071] The reduction rate of the gas barrier properties of the laminate as determined by the water resistance test described below is preferably 50% or less, more preferably 20% or less, and even more preferably 15% or less. When the reduction rate of the gas barrier properties is 50% or less, the laminate exhibits excellent water resistance. Furthermore, when the reduction rate of the gas barrier properties is within the above range and the molar ratio of the hydrophobic portion in the copolymer is high, the laminate exhibits even better water resistance.

[0072] <Water resistance test>

[0073] Cut out from the laminate The test piece is immersed in 1L of water at room temperature for 15 minutes and then naturally dried at room temperature. For the above-mentioned test piece, the immersion and drying are repeated 50 cycles as a cycle to obtain a test piece after the water resistance test. Then, the air barrier (air barrier after the water resistance test) of the obtained test piece after the water resistance test is measured. Then, the reduction rate of the air barrier is calculated according to the following formula. It should be noted that the above-mentioned initial air barrier and the air barrier after the above-mentioned water resistance test are both air barrier based on the Gurley method of JIS P8117-2009.

[0074] Reduction rate of gas barrier degree (%) = [(initial gas barrier degree) - (gas barrier degree after water resistance test)] / (initial gas barrier degree) × 100

[0075] The gas barrier property of the laminate after the water resistance test according to the Gurley method of JIS P8117-2009 is preferably 3000 sec / 100 cc or higher, more preferably 4000 sec / 100 cc or higher, and even more preferably 5000 sec / 100 cc or higher. The laminate has excellent water resistance and moisture permeability, and therefore, a configuration in which the gas barrier property after the water resistance test is 3000 sec / 100 cc or higher can be employed.

[0076] The laminate can be produced by forming the moisture-permeable membrane on at least one surface of a porous substrate using a known or customary method. For example, the moisture-permeable membrane can be formed directly on one surface of the porous substrate, or the moisture-permeable membrane can be temporarily formed on another support and then transferred (laminated) to one surface of the porous substrate to form the moisture-permeable membrane on the porous substrate. The former method is preferred because it provides excellent adhesion between the moisture-permeable membrane and the porous substrate.

[0077] The surface of the porous substrate on the side where the moisture-permeable membrane is provided may be subjected to a hydrophilic treatment. Examples of the hydrophilic treatment include the treatments described above.

[0078] The moisture-permeable film can be formed by applying (coating) the composition for forming the moisture-permeable film onto the porous substrate or the other support, and removing the solvent from the resulting coating by heating or the like.

[0079] The above-mentioned composition can be made using a known or customary method. For example, in the case where the above-mentioned laminate has a moisture-permeable film formed by the above-mentioned copolymer, the above-mentioned composition can be made by dissolving or dispersing the above-mentioned copolymer in a solvent and mixing a preservative as needed. As the above-mentioned solvent, water and / or a water-soluble solvent are preferred. It can be inferred that when water or a water-soluble solvent is used, the above-mentioned copolymer is dispersed in the composition in a core-shell shape with the inner side being the hydrophobic portion and the outer side being the hydrophilic portion. By using such a composition, when the coating is dried, the hydrophilic portion and the hydrophobic portion are separated, and a moisture-permeable film is formed in a state with a water-conducting channel. In addition, it can be inferred that the hydrophobic portions become firmly bonded to each other, and the water resistance becomes better.

[0080] Examples of the water-soluble solvent include aliphatic water-soluble alcohols such as methanol, ethanol, n-propanol, and isopropanol; and glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. These water-soluble solvents may be used alone or in combination of two or more.

[0081] The ratio (concentration) of the copolymer in the composition in which the copolymer is dissolved or dispersed is not particularly limited, but is preferably 0.5% to 5% by mass, more preferably 1% to 4% by mass, and even more preferably 1.5% to 3% by mass. When the concentration is 5% by mass or less, the thickness of the coating layer becomes thicker, and thus the thickness of the moisture-permeable film after drying becomes more uniform. As a result, a moisture-permeable film with excellent gas barrier properties and a further thin film can be formed, and as a result, the moisture permeability is further improved. In addition, when the concentration is within the above range, the coating property is excellent, and it is easy to form a moisture-permeable film with excellent moisture permeability and gas barrier properties.

[0082] It should be noted that the composition may be applied by any known coating method. For example, a coating machine such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a comma coater, or a direct coater may be used.

[0083] The heating temperature for desolvation of the coating is preferably 35°C to 90°C, more preferably 40°C to 85°C, and even more preferably 45°C to 80°C. The heating time can be appropriately selected, for example, 5 seconds to 20 minutes, preferably 5 seconds to 10 minutes, and more preferably 10 seconds to 5 minutes. The composition can be used to form a moisture-permeable film at low temperatures of 90°C or lower (particularly 80°C or lower), making film formation easy. Furthermore, a polyolefin resin with excellent moisture permeability can be used as the porous substrate.

[0084] The above-mentioned laminate has low air permeability and excellent moisture permeability. Furthermore, it also has excellent moisture permeability and water resistance in low-temperature and low-humidity environments. Therefore, the above-mentioned laminate can be preferably used in products requiring such functions, such as total heat exchange devices, clothing linings, disposable waterproof / moisture-permeable materials, and applications that require dehydration without exposure to air or bacteria (such as filters for storing aged meat). The laminate used in the above-mentioned total heat exchange device is, for example, a sheet material that can exchange humidity (latent heat) between the incoming air and the outgoing air, along with temperature (sensible heat).

[0085] By deforming the above-mentioned stacked body into a corrugated shape as needed and then stacking it, a total heat exchange device (total heat exchange sheet) can be made. The above-mentioned total heat exchange device can be any of a direct current type and a convection type. The total heat exchange device using the above-mentioned stacked body has low air permeability and excellent moisture permeability (especially moisture permeability in a low temperature and low humidity environment) and water resistance. The above-mentioned total heat exchange device can be used as a total heat exchange device of an air conditioner. The above-mentioned air conditioner uses a total heat exchange device with low air permeability and excellent moisture permeability, and also excellent moisture permeability and water resistance in a low temperature and low humidity environment. Therefore, the indoor heat preservation and moisture retention are excellent, and the durability is excellent even in a low temperature and low humidity environment.

[0086] The various schemes disclosed in this specification can be combined with any other features disclosed in this specification. The various configurations and combinations of configurations in the various embodiments are merely examples, and appropriate additions, omissions, substitutions, and other modifications may be made without departing from the scope of the present disclosure. Furthermore, the various inventions disclosed herein are not limited by the embodiments or the following examples, but only by the patent claims.

[0087] Example

[0088] Hereinafter, one embodiment of the present disclosure will be described in more detail based on examples.

[0089] Example 1

[0090] A random copolymer of 2-methacryloyloxyethyl phosphorylcholine and stearyl methacrylate (structural unit ratio [former / latter]: 1 / 1, concentration: 4% by mass, weight-average molecular weight: 100,000) was diluted with distilled water to produce a 2% by mass composition. Separately, one surface of a porous polyolefin resin substrate (thickness: 20 μm, porosity: 48% by volume, surface tension: 32 dyn) was corona treated to form a hydrophilic surface with a surface tension of 46 dyn. The composition was then applied to the hydrophilic surface of the porous substrate using a coater and heated at 50°C for 3 minutes to form a moisture-permeable film (thickness: 100 nm to 500 nm). This produced the laminate of Example 1.

[0091] Example 2

[0092] A laminate of Example 2 was produced in the same manner as in Example 1 except that a porous substrate made of a polyolefin-based resin (thickness: 12 μm, porosity: 40 vol%, surface tension: 32 dyn) was used as the porous substrate.

[0093] Example 3

[0094] A laminate of Example 3 was produced in the same manner as in Example 1 except that a porous substrate made of a polyolefin-based resin (thickness: 25 μm, porosity: 56 vol%, surface tension: 32 dyn) was used as the porous substrate.

[0095] Comparative Example 1

[0096] Total heat exchange sheets contained in a commercially available total heat exchanger were taken out and used as the laminate of Comparative Example 1. This laminate used paper (thickness: 30 μm) as a porous substrate, and the porous substrate was impregnated with a deliquescent inorganic salt as a moisture permeability-enhancing component.

[0097] (evaluate)

[0098] Each laminate obtained in the Examples and Comparative Examples was evaluated as follows. The evaluation results are shown in the table. Note that "-" in the table indicates that no evaluation was performed.

[0099] (1) Gas barrier

[0100] The gas barrier properties of the laminates obtained in Examples and Comparative Examples were measured according to the Gurley method of JIS P8117-2009. Specifically, 5 cm x 5 cm test pieces were cut out from the laminates obtained in Examples and Comparative Examples, placed in a Gurley apparatus, and the number of seconds it took for 100 cc of air to flow was measured using a stopwatch.

[0101] (2) Moisture permeability

[0102] The moisture permeability of the laminates obtained in the Examples and Comparative Examples was measured according to the moisture permeability test method (cup method) of JIS Z0208-1976. Specifically, 30 g of calcium chloride was placed in a moisture permeable cup. The laminates obtained in the Examples and Comparative Examples were allowed to stand for at least 2 hours under the measurement environment. The laminates were then covered with the moisture permeable cup as a moisture permeable sheet to achieve airtightness. The combined mass increase of the calcium chloride and the moisture permeable cup over one hour in a substantially windless environment (wind speed 0.2 m / s or less) was converted to a value per m² of the test piece. 2 The mass after 24 hours is measured as a moisture permeability meter. It should be noted that the first moisture permeability was measured at a temperature of 5°C and a relative humidity of 45%, and the second moisture permeability was measured at a temperature of 20°C and a relative humidity of 65%. The first and second moisture permeabilities obtained were respectively converted into the absolute mass [g / m 3 ] is set as x-axis, moisture permeability [g / (m 2 ·24h)] is set as the y-axis, marked, and a linear function curve graph is produced. The curve graph produced is as follows Figure 2 shown.

[0103] [Table 1]

[0104]

[0105] As shown in the table, the laminated bodies of the examples were evaluated to have high gas barrier properties, i.e., low air permeability, and excellent moisture permeability (Examples 1 to 3). In particular, the moisture permeability was 500 g / (m 2 · 24h) or more, it was evaluated that the moisture permeability in a low-temperature and low-humidity environment was excellent. On the other hand, the laminate of Comparative Example 1 was evaluated to be poor in moisture permeability.

[0106] Modifications of the disclosed invention will be described below.

[0107] [Supplementary Note 1] A laminate comprising: a porous substrate; and a moisture-permeable membrane provided on one surface of the porous substrate, wherein the laminate has an air barrier of 3000 sec / 100 cc or more based on the Gurley method of JIS P8117-2009, and a first moisture permeability of 300 g / (m2) under the conditions of a temperature of 5°C, a relative humidity of 45%, and a wind speed of 0.2 m / s or less based on the moisture permeability test method (cup method) of JIS Z0208-1976. 2 ·24h) or more.

[0108] [Supplementary Note 2] The laminate according to Supplementary Note 1, wherein the gas barrier property measured by the Gurley method according to JIS P8117-2009 is 4000 sec / 100 cc or more, preferably 5000 sec / 100 cc or more.

[0109] [Supplementary Note 3] The laminate according to Supplementary Note 1 or 2, wherein the gas barrier property according to the Gurley method in accordance with JIS P8117-2009 is 150,000 sec / 100 cc or less (preferably 100,000 sec / 100 cc or less, more preferably 80,000 sec / 100 cc or less).

[0110] [Supplementary Note 4] The laminate according to any one of Supplementary Notes 1 to 3, wherein the first moisture permeability is 300 g / (m 2 ·24h) or more (preferably 400g / (m 2 ·24h) or more, more preferably 500g / (m 2 ·24h) or more).

[0111] [Supplementary Note 5] The laminate according to any one of Supplementary Notes 1 to 4, wherein the first moisture permeability is 5000 g / (m 2 ·24h) or less (preferably 2000g / (m 2 ·24h) or less, more preferably 1000g / (m 2 ·24h or less).

[0112] [Supplementary Note 6] The laminate according to any one of Supplementary Notes 1 to 5, wherein the second moisture permeability is 1600 g / (m 2 ·24h) or more (preferably 1700g / (m 2·24h) or more, more preferably 1800g / (m 2 ·24h) or more).

[0113] [Supplementary Note 7] The laminate according to any one of Supplementary Notes 1 to 6, wherein, with respect to the first moisture permeability and the second moisture permeability under the conditions of a temperature of 20°C, a relative humidity of 65%, and a wind speed of 0.2 m / s or less, in accordance with the moisture permeability test method (cup method) of JIS Z0208-1976, in a graph where the volume absolute humidity under the moisture permeability measurement conditions is set as x and the moisture permeability is set as y, a linear function obtained by connecting two points of the first moisture permeability and the second moisture permeability, when expressed by the equation y=ax+b, satisfies a ≥ 154 and b ≥ -170.

[0114] [Supplementary Note 8] The laminate according to Supplementary Note 7, wherein a in the equation is 155 or greater (preferably 160 or greater, more preferably 180 or greater).

[0115] [Supplementary Note 9] The laminate according to Supplementary Note 7 or 8, wherein b in the equation is -150 or greater (preferably -130 or greater, more preferably -110 or greater).

[0116] [Supplementary Note 10] The laminate according to any one of Supplementary Notes 1 to 9, wherein the moisture-permeable film is formed of a resin.

[0117] [Supplementary Note 11] The laminate according to Supplementary Note 10, wherein the resin has a hydrophilic group (preferably a cationic group and an anionic group, more preferably a phosphorylcholine group).

[0118] [Supplementary Note 12] The laminate according to Supplementary Note 10 or 11, wherein the resin has a hydrophobic group (preferably a hydrocarbon group having 2 or more carbon atoms, more preferably R in the structural unit represented by formula (2) 6 ).

[0119] [Supplementary Note 13] The laminate according to any one of Supplementary Notes 10 to 12, wherein the resin includes a copolymer including a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2).

[0120] [Chemical Formula 1]

[0121]

[0122] [In formula (1), R 1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 2 、R 3 and R 4are the same or different and represent an alkyl group having 1 to 4 carbon atoms. X represents a divalent hydrocarbon group having 1 to 4 carbon atoms. Y represents a divalent linear hydrocarbon group having 1 to 4 carbon atoms.

[0123] [Chemical Formula 2]

[0124]

[0125] [In formula (2), R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 6 represents a hydrocarbon group having 2 or more carbon atoms]

[0126] [Supplementary Note 14] The laminate according to Supplementary Note 13, wherein in the formula (1), R 1 is a hydrogen atom or a methyl group (preferably a methyl group).

[0127] [Supplementary Note 15] The laminate according to Supplementary Note 13 or 14, wherein in the formula (1), R 2 、R 3 and R 4 It is a methyl group.

[0128] [Supplement 16] The laminate according to any one of Supplements 13 to 15, wherein in the formula (1), X is a linear or branched alkylene group having 1 to 4 carbon atoms (preferably a linear alkylene group having 1 to 4 carbon atoms).

[0129] [Supplementary Note 17] The laminate according to any one of Supplementary Notes 13 to 16, wherein in the formula (1), Y is an alkylene group having 1 to 4 carbon atoms (preferably a dimethylene group).

[0130] [Supplementary Note 18] The laminate according to any one of Supplementary Notes 13 to 17, wherein the monomer forming the structural unit represented by the formula (1) is 2-methacryloyloxyethylphosphocholine.

[0131] [Supplementary Note 19] The laminate according to any one of Supplementary Notes 13 to 18, wherein in the formula (2), R 5 is a hydrogen atom or a methyl group (preferably a methyl group).

[0132] [Supplementary Note 20] The laminate according to any one of Supplementary Notes 13 to 19, wherein in the formula (2), R 6 It is a hydrocarbon group (preferably an aliphatic hydrocarbon group, more preferably a linear or branched alkyl group, and even more preferably a linear alkyl group) having 4 to 26 carbon atoms (preferably 8 to 22, more preferably 10 to 20, and even more preferably 14 to 18).

[0133] [Supplementary Note 21] The laminate according to any one of Supplementary Notes 13 to 20, wherein the monomer forming the structural unit represented by the formula (2) is stearyl (meth)acrylate.

[0134] [Note 22] The laminate according to any one of Notes 13 to 21, wherein the molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) [former / latter] is 1 / 100 to 100 / 1 (preferably 0.01 to 90, more preferably 0.02 to 80, further preferably 0.1 to 20, and particularly preferably 0.5 to 5).

[0135] [Note 23] A laminate according to any one of Notes 13 to 22, wherein the total molar number of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) is 50 mol% or more (preferably 90 mol%, more preferably 99 mol% or more) relative to the total molar number of the structural units derived from all monomers constituting the copolymer.

[0136] [Supplementary Note 24] The laminate according to any one of Supplementary Notes 13 to 23, wherein the weight average molecular weight of the copolymer is 20,000 to 2,000,000 (preferably 30,000 to 1,500,000, more preferably 50,000 to 1,000,000, and even more preferably 70,000 to 500,000).

[0137] [Supplementary Note 25] The laminate according to any one of Supplementary Notes 13 to 24, wherein the copolymer is a random copolymer of a monomer forming the structural unit represented by the formula (1) and a monomer forming the structural unit represented by the formula (2).

[0138] [Supplementary Note 26] The laminate according to any one of Supplementary Notes 1 to 25, wherein the material forming the porous base material is a hydrophobic material (preferably a polyolefin-based resin, more preferably a polypropylene-based resin).

[0139] [Supplementary Note 27] The laminate according to any one of Supplementary Notes 1 to 26, wherein the porosity of the porous substrate is 30% by volume to 90% by volume (preferably 40% by volume to 70% by volume).

[0140] [Supplementary Note 28] The laminate according to any one of Supplementary Notes 1 to 27, wherein a surface of the porous substrate on the side provided with the moisture-permeable membrane is subjected to a hydrophilizing treatment.

[0141] [Supplementary Note 29] The laminate according to any one of Supplementary Notes 1 to 28, wherein the surface tension of the surface of the porous substrate on the side where the moisture-permeable membrane is formed is 35 dyn / cm to 55 dyn / cm (preferably 37 dyn / cm to 50 dyn / cm).

[0142] [Supplementary Note 30] The laminate according to any one of Supplementary Notes 1 to 29, wherein the surface tension of the interior of the porous substrate, which is a region where the moisture-permeable film is not formed, is less than 35 dyn / cm (preferably 33 dyn / cm or less).

[0143] [Supplementary Note 31] The laminate according to any one of Supplementary Notes 1 to 30, wherein the reduction rate of the gas barrier property obtained by the following water resistance test is 50% or less (preferably 20% or less, more preferably 15% or less).

[0144] <Water resistance test>

[0145] Cut out from the laminate The test piece is immersed in water at room temperature for 15 minutes and then naturally dried at room temperature. For the test piece, the immersion and drying are repeated 50 times as a cycle to obtain a test piece after the water resistance test. Then, the air barrier after the water resistance test of the obtained test piece is measured. Then, the reduction rate of the air barrier is calculated according to the following formula. It should be noted that the initial air barrier and the air barrier after the water resistance test are both air barrier based on the Gurley method of JIS P8117-2009.

[0146] Reduction rate of gas barrier degree (%) = [(initial gas barrier degree) - (gas barrier degree after water resistance test)] / (initial gas barrier degree) × 100

[0147] [Note 32] The laminate according to any one of Notes 1 to 31, wherein the air barrier after the following water resistance test based on the Gurley method of JIS P8117-2009 is 3000 seconds / 100cc or more (preferably 4000 seconds / 100cc or more, more preferably 5000 seconds / 100cc or more).

[0148] <Water resistance test>

[0149] Cut out from the laminate A test piece was immersed in room temperature water for 15 minutes and then naturally dried at room temperature. This immersion and drying cycle was repeated 50 times to obtain a water resistance test piece. The gas barrier properties of the water resistance test piece were then measured.

[0150] Industrial applicability

[0151] The laminated body of the present disclosure has low air permeability and excellent moisture permeability, and also has excellent moisture permeability in low-temperature and low-humidity environments, and can therefore be particularly preferably used as a total heat exchange sheet. Therefore, the present disclosure has industrial applicability.

[0152] Description of Reference Numerals

[0153] 1 laminate

[0154] 11. Porous substrate

[0155] 11a One surface of the porous substrate

[0156] 12 Moisture permeable membrane

Claims

1. A laminate comprising: A porous substrate; and a moisture-permeable membrane provided on at least one surface of the porous substrate. The moisture-permeable membrane comprises a resin having a hydrophilic group and a hydrophobic group, wherein the hydrophilic group comprises a cationic group and an anionic group. The resin is a copolymer further comprising a structural unit represented by the following formula (2), In formula (2), R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 6 represents a hydrocarbon group having 4 or more carbon atoms, The thickness of the moisture permeable film is 50 to 500 nm. The laminate has a gas barrier property of 3000 sec / 100 cc or more according to the Gurley method of JIS P8117-2009. The first moisture permeability is 300 g / (m 2 ·24h) or more.

2. The laminate according to claim 1, wherein Regarding the first moisture permeability test and the second moisture permeability test based on the moisture permeability test method (cup method) of JIS Z0208-1976 under the conditions of a temperature of 20°C, a relative humidity of 65%, and a wind speed of 0.2 m / s or less, In a graph where the volume absolute humidity under moisture permeability measurement conditions is x and the moisture permeability is y, when a linear function obtained by connecting the two points of the first moisture permeability and the second moisture permeability is expressed by the equation y=ax+b, a≥154 and b≥-170 are satisfied.

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