JP7146867B2 - laminate - Google Patents

Description

The present disclosure relates to laminates. More particularly, it relates to a laminate comprising a porous substrate and a moisture-permeable film provided on at least one surface of the porous substrate.

2. Description of the Related Art Conventionally, a heat exchange ventilator that exchanges heat between supply air and exhaust air during ventilation is known as a device that can ventilate without impairing the effect of cooling or heating.

A heat exchange sheet for exchanging heat is used in a heat exchange type ventilator. A heat exchange sheet is a partition member that physically separates supply air and exhaust air. Heat transfer is required for heat exchange between them. In addition, the heat exchange sheet (total heat exchange sheet) used in the total heat exchanger, which exchanges both temperature (sensible heat) and humidity (latent heat) between the supply air and the exhaust air, further has high moisture permeability. is also required.

As a heat exchange sheet used in a total heat exchanger, for example, one that uses a moisture permeable membrane formed from low-molecular compounds such as deliquescent calcium chloride, lithium chloride, sulfuric acid, and sodium hydroxide is considered. be done. Among them, a moisture-permeable membrane made of calcium chloride or lithium chloride is widely used from the viewpoint of safety. However, moisture-permeable membranes formed from deliquescent compounds or low-molecular-weight compounds have high solubility in water and poor water resistance.

The heat exchange sheet used in the total heat exchanger also has a porous substrate and a hydrophilic polymer compound provided on the surface and inside of the porous substrate, and the hydrophilic polymer compound is , a partition member for a total heat exchange sheet, which is a polymer of a compound having a quaternary ammonium group and an amide group (see Patent Document 1).

JP 2014-55683 A

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. In particular, the moisture permeability was insufficient in a low-temperature, low-humidity environment.

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

The inventors of the present disclosure have made intensive studies to achieve the above object, and found that a porous substrate and a moisture-permeable moisture-permeable material provided on at least one surface of the porous substrate and formed from a specific copolymer It was found that a laminate having a membrane has low air permeability and excellent moisture permeability. The present disclosure relates to what was completed based on these findings.

The present disclosure includes a porous substrate and a moisture permeable membrane provided on at least one surface of the porous substrate, wherein the moisture permeable membrane has a side chain containing a betaine group as a functional group. A laminate is provided that is formed from a plastic copolymer.

Preferably, the above copolymer further has a hydrophobic functional group on its side chain.

［式（１）中、Ｒ¹は、水素原子又は炭素数１～４のアルキル基を示す。Ｘは、炭素数１～４の二価の炭化水素基を示す。Ｙは、炭素数１～４の二価の直鎖状炭化水素基を示す。Ｚ¹は、Ｏ又はＮＨを示す。α及びβは、カチオン及びアニオンの組み合わせを示す。］

［式（２）中、Ｒ²は、水素原子又は炭素数１～４のアルキル基を示し、Ｒ³は、炭素数２以上の炭化水素基を示す。Ｚ²は、Ｏ又はＮＨを示す。］ The copolymer has a structural unit represented by the following formula (1) as a structural unit having a side chain containing a betaine group, and a structural unit having a hydrophobic functional group in a side chain represented by the following formula (2). from a copolymer having a structural unit represented by the above formula (1) and a structural unit represented by the above formula (2) in a molar ratio of 1/100 to 100/1 preferably formed.

[In formula (1), R ¹ represents a hydrogen atom or 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. Z ¹ represents O or NH. α and β represent a combination of cations and anions. ]

[In formula (2), R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ represents a hydrocarbon group having 2 or more carbon atoms. Z ² represents O or NH. ]

The cation in formula (1) above is preferably an ammonium ion.

The anion in formula (1) above is preferably a phosphate ion, a sulfate ion, or a carbonate ion.

［式（１－１）～（１－３）中、Ｘ及びＹは上記に同じであり、カルボニル炭素原子の左側の結合手は式（１）中のＲ¹を有する炭素原子に結合する。式（１－１）中、Ｒ⁵、Ｒ⁶、及びＲ⁷は、同一又は異なって、炭素数１～４のアルキル基を示す。式（１－２）及び式（１－３）中、Ｒ⁸及びＲ⁹は、同一又は異なって、炭素数１～４のアルキル基を示す。］ The above formula (1) may include a group represented by the following formula (1-1), a group represented by the following formula (1-2), or a group represented by the following formula (1-3). preferable.

[In formulas (1-1) to (1-3), X and Y are the same as above, and the left bond of the carbonyl carbon atom bonds to the carbon atom having R ¹ in formula (1). In formula (1-1), R ⁵ , R ⁶ and R ⁷ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. In formulas (1-2) and (1-3), R ⁸ and R ⁹ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. ]

The weight average molecular weight of the copolymer is preferably 20,000 to 2,000,000.

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). is preferred.

It is preferable that the surface of the porous substrate on which the moisture-permeable membrane is provided is subjected to a hydrophilic treatment.

Based on the moisture permeability test method of JIS Z0208-1976, the moisture permeability is preferably 1,600 g/(m ² ·24 h) or more under the conditions of temperature 20° C., relative humidity 65%, and wind speed 0.2 m/sec or less.

Preferably, the surface of the moisture permeable membrane has a structure in which a hydrophilic portion and a hydrophobic portion are phase-separated, and the maximum diameter of the hydrophilic portion on the surface of the moisture permeable membrane is 50 nm or less.

The laminate of the present disclosure has low air permeability and excellent moisture permeability. It also has excellent moisture permeability in a low-temperature, low-humidity environment. Therefore, the laminate of the present disclosure can be particularly preferably used as a total heat exchange sheet.

It is a cross-sectional schematic diagram which shows one Embodiment of the laminated body of this indication.

A laminate according to an embodiment of the present disclosure includes at least a porous substrate and a moisture permeable film provided on at least one surface of the porous substrate. The moisture-permeable membrane may be provided on one side of the porous substrate, or may be provided on both sides. Further, the laminate may have a structure in which the moisture-permeable membrane is sandwiched between two porous substrates. That is, the porous substrate may be provided on both sides of the moisture permeable membrane. The two porous substrates in this case may be the same porous substrate, or may be porous substrates having different materials, thicknesses, and the like.

FIG. 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 film 12 provided on one surface 11 a of the porous substrate 11 .

The moisture-permeable membrane is formed from a thermoplastic copolymer having a side chain containing a betaine group as a functional group. The copolymer has a side chain containing the betaine group, and thus has a group that is amphoteric and highly hydrophilic, and has a hydrophilic portion. For this reason, a hydrophilic portion is formed in the moisture-permeable film formed from the copolymer, and the hydrophilic portion functions as a water-conducting path, allowing more water vapor to pass through, and is presumed to have excellent moisture permeability. be. In general, a moisture permeable membrane formed from calcium chloride or potassium chloride tends to have an extremely low moisture absorption rate and poor moisture permeability in a low-temperature, low-humidity environment. The moisture-permeable membrane has excellent moisture-permeability even in a low-temperature, low-humidity environment without an extreme decrease in moisture absorption. The betaine group-containing side chain may have one kind or two or more kinds.

The above thermoplastic copolymer means that the polymer main chain is a thermoplastic resin. Examples of the thermoplastic resin include acrylic resins, cellulose resins, polyester resins such as polybutylene terephthalate, polyether resins, polyurethane resins, polyvinyl chloride resins, polyethylene, polystyrene resins, and polyamide resins. , polyacetal-based resins, polycarbonate-based resins, polyphenylene sulfide-based resins, polyetheretherketone-based resins, polyimide-based resins, polytetrafluoroethylene-based resins, polycaprolactone, and polylactic acid.

The above copolymer preferably further has a hydrophobic functional group in its side chain. The copolymer has a hydrophobic part by having side chains containing the hydrophobic functional groups in addition to the side chains containing the betaine groups. As a result, a hydrophilic portion and a hydrophobic portion are formed in the moisture-permeable film formed from the copolymer. Therefore, in the moisture-permeable film formed from the copolymer, a structure in which the hydrophilic portion and the hydrophobic portion are phase-separated is formed, and the hydrophilic portion functions as a water-conducting path, allowing more water vapor to pass through. It is presumed to have better moisture permeability. Hydrophobic functional groups include hydrocarbon groups having 2 or more carbon atoms. The hydrophobic functional group may have only one type, or may have two or more types.

［式（１）中、Ｒ¹は、水素原子又は炭素数１～４のアルキル基を示す。Ｘは、炭素数１～４の二価の炭化水素基を示す。Ｙは、炭素数１～４の二価の直鎖状炭化水素基を示す。Ｚ¹は、Ｏ又はＮＨを示す。α及びβは、カチオン及びアニオンの組み合わせを示す。］

［式（２）中、Ｒ²は、水素原子又は炭素数１～４のアルキル基を示し、Ｒ³は、炭素数２以上の炭化水素基を示す。Ｚ²は、Ｏ又はＮＨを示す。］ The copolymer has a structural unit represented by the following formula (1) as a structural unit having a side chain containing a betaine group, and a structural unit having a hydrophobic functional group in a side chain represented by the following formula (2). It is preferable to include the represented structural unit. In the copolymer, the molar ratio of the structural unit represented by formula (1) to the structural unit represented by formula (2) is preferably 1/100 to 100/1.

[In formula (1), R ¹ represents a hydrogen atom or 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. Z ¹ represents O or NH. α and β represent a combination of cations and anions. ]

[In formula (2), R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ represents a hydrocarbon group having 2 or more carbon atoms. Z ² represents O or NH. ]

By including the structural unit represented by the formula (1), the copolymer has amphoteric and highly hydrophilic groups derived from α and β, and has a hydrophilic portion. Moreover, the above copolymer has an alkyl ester portion having 2 or more carbon atoms, which is a hydrophobic portion, by including the structural unit represented by the above formula (2). When the molar ratio is within the above range, the hydrophilic portion and the hydrophobic portion are present in a well-balanced manner in the copolymer. Therefore, in the moisture-permeable film formed from the copolymer, a structure in which the hydrophilic portion and the hydrophobic portion are phase-separated is formed, and the hydrophilic portion functions as a water-conducting path, allowing more water vapor to pass through. It is presumed to have excellent moisture permeability. In general, a moisture permeable membrane formed from calcium chloride or potassium chloride tends to have an extremely low moisture absorption rate and poor moisture permeability in a low-temperature, low-humidity environment. The moisture-permeable membrane has excellent moisture-permeability even in a low-temperature, low-humidity environment without an extreme decrease in moisture absorption. In addition, when the proportion of the hydrophobic portion in the molar ratio of the hydrophilic portion and the hydrophobic portion is increased, a moisture-permeable membrane that is excellent in moisture permeability, is difficult to dissolve in water, and is also excellent in water resistance can be obtained. Furthermore, since the aqueous solution of the above copolymer has a weakly acidic pH, corrosion of metals is less likely to occur than moisture permeable membranes using conventional strongly acidic resins having acidic functional groups such as sulfonyl groups ( That is, it is excellent in metal corrosion resistance).

［式（１’）中、Ｒ⁴は、二価の炭化水素基を示す。Ｒ¹、Ｘ、Ｙ、Ｚ¹、α、及びβは上記に同じである。］ Examples of structural units containing structural units represented by formula (1) above include structural units represented by formula (1′) below.

[In Formula (1′), R ⁴ represents a divalent hydrocarbon group. R ¹ , X, Y, Z ¹ , α, and β are the same as above. ]

In formula (1′), R ⁴ represents a divalent hydrocarbon group, and examples thereof include alkylene groups having 1 to 4 carbon atoms such as methylene and ethylene. Examples of structural units represented by the above formula (1′) when R ⁴ is a methylene group include structural units derived from acrylic acid esters and structural units derived from methacrylic acid esters. The divalent hydrocarbon group may have a substituent.

In formula (1), R ¹ 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.

In formula (1), X represents a divalent hydrocarbon group having 1 to 4 carbon atoms, such as an alkylene group, an alkenylene group, an alkynylene group, and the like. Examples of alkylene groups include linear or branched C _1-4 alkylene groups such as methylene, dimethylene, trimethylene, isopropylene and tetramethylene groups. Examples of alkenylene groups include linear or branched C _2-4 alkenylene groups such as ethynylene, 1-propenylene, isopropenylene, 1-butenylene, 2-butenylene and 3-butenylene groups. mentioned. The divalent hydrocarbon group is preferably a linear or branched alkylene group, more preferably a linear alkylene group.

In formula (1), Y represents a divalent linear hydrocarbon group having 1 to 4 carbon atoms, such as an alkylene group, an alkenylene group, an alkynylene group, and the like. Alkylene groups include methylene, dimethylene, trimethylene and tetramethylene groups. Examples of alkenylene groups include ethynylene, 1-propenylene and 1-butenylene groups. Among them, the divalent straight-chain hydrocarbon group is preferably an alkylene group, more preferably a straight-chain alkylene group. By adjusting the number of carbon atoms of X and Y within the above range, the balance between hydrophobicity and hydrophilicity is optimized.

In formula (1), Z ¹ represents O or NH. That is, the divalent linking group Z ¹ is —O— (ether bond) or an amino bond (—NH—), and in the structural unit represented by the above formula (1), together with the adjacent carbonyl carbon, form an ester bond or an amide bond.

In formula (1), α and β are a combination of cations and anions. That is, α is a cation and β is an anion, or α is an anion and β is a cation. Ammonium ion is preferable as the cation. The anions are preferably phosphate ions (--PO ₄ ^- ), sulfate ions (--SO ₃ ^- ), or carbonate ions (--CO ₂ ^- ). When the anion is a phosphate ion, the structural unit represented by the formula (1) contains phosphobetaine, and when the anion is a sulfate ion, the structural unit represented by the formula (1) is sulfobetaine. and when the anion is a carbonate ion, the structural unit represented by the formula (1) includes carbobetaine. The anion may have a resonance structure in the copolymer.

［式（１－１）～（１－３）中、Ｘ及びＹは上記に同じであり、カルボニル炭素原子（式（１－３）においては左側のカルボニル炭素原子）の左側の結合手は式（１）中のＲ¹を有する炭素原子に結合する。式（１－１）中、Ｒ⁵、Ｒ⁶、及びＲ⁷は、同一又は異なって、炭素数１～４のアルキル基を示す。式（１－２）及び式（１－３）中、Ｒ⁸及びＲ⁹は、同一又は異なって、炭素数１～４のアルキル基を示す。］ represented by the above formula (1), wherein the cation is an ammonium ion and the anion is a phosphate ion (—PO ₄ ⁻ ), a sulfate ion (—SO ₃ ⁻ ), or a carbonate ion (—CO ₂ ⁻ ); Examples of the structural unit include those having groups represented by the following formulas (1-1) to (1-3).

[In formulas (1-1) to (1-3), X and Y are the same as above, and the bond on the left side of the carbonyl carbon atom (the left carbonyl carbon atom in formula (1-3)) is the formula It binds to the carbon atom having R ¹ in (1). In formula (1-1), R ⁵ , R ⁶ and R ⁷ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. In formulas (1-2) and (1-3), R ⁸ and R ⁹ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. ]

In formula (1-1), R ⁵ , R ⁶ and R ⁷ 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 group, ethyl group, propyl group, butyl group and t-butyl group. Among them, a methyl group is preferred.

In formula (1-1), X is preferably a dimethylene group and Y is a dimethylene group.

Examples of the monomer forming the structural unit represented by formula (1-1) above include 2-methacryloyloxyethylphosphorylcholine.

［式（１’－１）中、Ｒ¹、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｘ、及びＹは上記に同じである。］ Examples of the structural unit represented by the above formula (1′) when containing the group represented by the above formula (1-1) include structural units represented by the following formula (1′-1).

[In formula (1′-1), R ¹ , R ⁵ , R ⁶ , R ⁷ , X and Y are the same as above. ]

In formula (1-2), R ⁸ and R ⁹ 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 group, ethyl group, propyl group, butyl group and t-butyl group. Among them, a methyl group is preferred.

In formula (1-2), X is preferably a trimethylene group and Y is a tetramethylene group.

In formula (1-3), R ⁸ and R ⁹ 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 group, ethyl group, propyl group, butyl group and t-butyl group. Among them, a methyl group is preferred.

In formula (1-3), it is preferred that X is a dimethylene group and Y is a methylene group.

In formula (2), R ² 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.

In formula (2), R ³ represents a hydrocarbon group having 2 or more carbon atoms. The number of carbon atoms is preferably 4 to 26, more preferably 8 to 22, still more preferably 10 to 20, and particularly preferably 14 to 18, from the viewpoint that the hydrophobicity of the hydrophobic portion is more moderate.

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 groups in which two or more of these are bonded.

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

Examples of the alicyclic hydrocarbon group include C _3-12 cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and cyclododecyl group; C _3-12 cycloalkenyl groups such as cyclohexenyl group; a _C4-15 bridged cyclic hydrocarbon group such as a bicycloheptanyl group and a bicycloheptenyl group;

Examples of the aromatic hydrocarbon group include C _6-14 aryl groups (especially C _6-10 aryl groups) such as phenyl group and naphthyl group.

Among them, the hydrocarbon group having 2 or more carbon atoms is preferably an aliphatic hydrocarbon group, more preferably a straight-chain or branched-chain alkyl group, and still more preferably a straight-chain alkyl group.

In formula (2), Z ² represents O or NH. That is, the divalent linking group Z ² is —O— (ether bond) or an amino bond (—NH—), and in the structural unit represented by the above formula (1), together with the adjacent carbonyl carbon, form an ester bond or an amide bond.

Examples of the monomer forming the structural unit represented by the above formula (2) include stearyl (meth)acrylate.

Each of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) may have only one type, or may have two or more types.

The molar ratio of the structural unit having the hydrophobic functional group in the side chain to the structural unit having the side chain containing the betaine group (preferably, the structural unit represented by the above formula (1) represented by the above formula (2) The molar ratio to the structural unit) [former/latter] is preferably 1/100 to 100/1 (that is, 0.01 to 100.0), more preferably 0.01 to 90, still more preferably 0.02 to 80, more preferably 0.1 to 20, particularly preferably 0.5 to 5.

The molar ratio [former/latter] 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 still more preferably 0.01 to 1.5. 3. In addition, in the energy histogram of the solute-solvent pair obtained from the process of calculating the free energy based on the energy representation method, the negative integral value of the hydrophilic portion and the hydrophobic portion is the attraction value for water, and the positive integral value is When the repulsive force value for water is used, the term indicated as the attractive force value is defined as the hydrophilic portion, and the term indicated as the repulsive force value is defined as the hydrophobic portion.

In the copolymer, the polymerization form of the structural unit having the side chain containing the betaine group and the structural unit having the hydrophobic functional group in the side chain (in particular, the structural unit represented by the above formula (1) and the above formula The copolymerization form of the structural unit represented by (2) is not particularly limited, and may be block copolymerization, alternating copolymerization, or random copolymerization. When the copolymer is a copolymer of a monomer forming a structural unit represented by the above formula (1) and a monomer forming a structural unit represented by the above formula (2), the copolymer The polymer may be a block copolymer, an alternating copolymer, or a random copolymer. Among them, the copolymer is preferably a random copolymer.

The copolymer may have structural units derived from other monomers other than the structural units represented by the formula (1) and the structural units represented by the formula (2). However, in the copolymer, the total number of moles of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) is derived from all the monomers constituting the copolymer. It is preferably 50 mol% or more, more preferably 90 mol% or more, and still more preferably 99 mol% or more, based on the total number of moles of the constituent units.

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, still more preferably 50,000 to 1,000,000, and particularly preferably 70,000 to 500,000. be. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated by polystyrene conversion.

The moisture-permeable membrane is formed from the copolymer. The moisture-permeable film may contain components other than the copolymer within a range that does not impair the effects of the laminate of the present disclosure.

The moisture-permeable membrane preferably contains a preservative as the other component. The antiseptic agent preferably has a smaller diameter than the thickness of the moisture permeable membrane from the viewpoint of preventing it from falling off from the moisture permeable membrane. The diameter of the antiseptic agent refers to the maximum particle size of the antiseptic agent.

Although the thickness of the moisture-permeable film is not particularly limited, it is preferably 50 to 1000 nm, more preferably 100 to 500 nm. When the thickness is 50 nm or more, the film formability is improved, leading to an improvement in gas barrier properties. When the thickness is 1000 nm or less, the moisture permeability becomes better. In addition, the moisture-permeable film can be easily formed into a thin film having a thickness of 1000 nm or less, and is economically efficient.

When the copolymer has a hydrophilic portion and a hydrophobic portion, due to this, the moisture-permeable membrane has a structure in which the hydrophilic portion and the hydrophobic portion are phase-separated on the surface. The maximum diameter of the hydrophilic portion on the surface of the moisture-permeable membrane is preferably 50 nm or less, more preferably 20 nm or less. When the maximum diameter of the hydrophilic portion is 50 nm or less, substances having a size exceeding 50 nm are less likely to permeate through the moisture permeable film, and the moisture permeable film serves as a barrier film that does not allow substances having a size of 50 nm or more (such as viruses) to permeate. can be used. The diameter of the hydrophilic portion is evaluated by the following method. By using the adhesive force measurement mode of a scanning probe microscope (SPM) to quantify the high adsorptive part (hydrophilic part) and the low adsorptive part (hydrophobic part) according to the adhesive force and processing it with image analysis software, The diameter of the hydrophilic portion can be calculated as the equivalent circle diameter. The maximum diameter is the largest diameter among the diameters (equivalent circle diameters) of the hydrophilic portion calculated as described above.

The porous substrate is an element that serves as a support for the moisture permeable membrane, and preferably has excellent moisture permeability.

The material forming the porous substrate may be either a hydrophilic material or a hydrophobic material, but a hydrophobic material is preferable. When the above hydrophobic material is used, when the aqueous composition for forming the moisture permeable film is applied, the aqueous composition does not penetrate into the porous substrate, so the aqueous composition does not reach the coating film forming surface of the porous substrate. There is no need for a lead substrate to prevent runoff from the opposite side.

Materials for forming the porous substrate include, for example, polyolefin resins, cellulose resins, polycarbonate resins, polyamide resins, polyimide resins, polyamideimide resins, fluorine resins, inorganic substances such as metals, glass and ceramics, and paper. is mentioned. Among them, the polyolefin resin is preferable because the moisture-permeable film can be formed on the porous substrate at a relatively low temperature and from the viewpoint of excellent moisture permeability and water resistance. The material may be fibrous such as metal fibers and inorganic fibers. The materials forming the porous base material may be of one kind, or may be of two or more kinds.

Examples of the porous substrate include resin porous membranes, inorganic porous membranes, metal porous membranes, and fibrous substrates.

The polyolefin-based resin is a polymer (including an olefin-based elastomer) composed of an olefin as an essential monomer component. It is a coalescence. Examples of the olefin include, but are not limited to, α-olefins such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene.

Examples of the polyolefin resin include a polymer (polyethylene resin) composed of ethylene as an essential monomer component, a polymer (polypropylene resin) composed of propylene as an essential monomer component, and an ionomer. , amorphous cyclic olefin polymers, and the like. Among them, polypropylene-based resins are preferred.

Although the porosity of the porous substrate is not particularly limited, it is preferably 30 to 90% by volume, more preferably 40 to 70% by volume. When the porosity is 30% by volume or more, the moisture permeability becomes better. When the porosity is 90% by volume or less, the support performance of the moisture-permeable membrane becomes better.

Although the thickness of the porous substrate is not particularly limited, it is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of being able to sufficiently support the moisture-permeable membrane. In addition, the thickness of the porous substrate is preferably 50 μm or less, more preferably 30 μm or less, in consideration of excellent moisture permeability and economy.

From the viewpoint of facilitating the formation of the moisture-permeable membrane, the surface of the porous substrate on which the moisture-permeable membrane is provided (for example, the surface 11a shown in FIG. 1) is preferably subjected to a hydrophilic treatment. preferable. In particular, when a hydrophobic material is used as the material forming the porous substrate, it is preferable that the hydrophilization treatment is performed. Examples of the hydrophilic treatment include corona discharge treatment and plasma treatment. By these hydrophilization treatments, a carboxy group, a hydroxy group, or a carbonyl group can be generated on the surface of the porous substrate, and the aqueous composition for forming the moisture-permeable membrane wets and spreads on the surface of the porous substrate. This facilitates the formation of the moisture-permeable membrane. In addition, this improves the adhesion between the porous substrate and the moisture-permeable film. Further, when the porous substrate formed from the hydrophobic substrate is stored as a roll, one surface and the other surface of the porous substrate are in contact with each other in the roll. Since one hydrophilic surface and the other hydrophobic surface come into contact with each other, blocking can be prevented.

The surface tension of the surface of the porous substrate on which the moisture-permeable membrane is formed is preferably 35 to 55 dyn/cm, more preferably 37 to 50 dyn/cm. When the surface tension is 35 dyn/cm or more, it becomes easy to apply the aqueous composition for forming the moisture permeable film, and the formation of the moisture permeable film becomes easy. When the surface tension is 55 dyn/cm or less, the aqueous composition for forming the moisture permeable film does not spread excessively, and the moisture permeable film can be easily formed on the surface of the porous substrate. When the surface of the porous substrate is hydrophilized, the surface on which the moisture-permeable membrane is to be formed is the hydrophilized surface.

The surface tension of the inside of the porous substrate (that is, the inside where the moisture-permeable membrane 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 for forming the moisture-permeable membrane is inhibited from penetrating into the porous substrate, and the porous substrate surface easily adheres to the moisture-permeable film. A moisture permeable membrane can be formed. In addition, when the surface of the porous substrate is hydrophilized, the inside of the porous substrate is the inside, which is a region not subjected to the hydrophilization treatment. Moreover, the internal surface tension can be obtained by measuring a cross section obtained by cutting the porous substrate.

The laminate has a moisture permeability of 1600 g/(m ²・24 h) or more, more preferably 1700 g/(m ² ·24 h) or more, and still more preferably 1800 g/(m ² ·24 h) or more. Since the laminate has excellent moisture permeability, it can be configured such that the moisture permeability is 1600 g/(m ² ·24 h) or more.

The laminate has a moisture permeability of 300 g/(m ²・24 h) or more, more preferably 400 g/(m ² ·24 h) or more, and still more preferably 500 g/(m ² ·24 h) or more. Since the laminate has excellent moisture permeability in a low-temperature, low-humidity environment, it can be configured such that the moisture permeability is 300 g/(m ² ·24 h) or more.

The laminate preferably has an air permeability resistance of 3000 seconds/100 cc or more, more preferably 4000 seconds/100 cc or more, still more preferably 5000 seconds/100 cc or more, based on the Gurley method of JIS P8117-2009. . Since the laminate has low air permeability, it can be configured such that the air resistance is 3000 sec/100 cc or more.

According to the water resistance test described below, the laminate preferably has a rate of decrease in air resistance of 50% or less, more preferably 20% or less, and still more preferably 15% or less. When the rate of decrease in air resistance is 50% or less, water resistance is excellent. Further, when the rate of decrease in air resistance is within the above range and the molar ratio of the hydrophobic portion in the copolymer is high, the water resistance is further excellent.
<Water resistance test>
A test piece with a diameter of 7 cm is cut out from the laminate, and the air resistance is measured (initial air resistance). After that, the test piece is immersed in 1 L of normal temperature water for 15 minutes, and then naturally dried at normal temperature. For the above test piece, this immersion and drying cycle is repeated 50 times to obtain a test piece after the water resistance test. Then, the air resistance of the obtained test piece after the water resistance test is measured (air resistance after the water resistance test). Then, the rate of decrease in air resistance is obtained from the following formula. Both the initial air resistance and the air resistance after the water resistance test are based on the Gurley method of JIS P8117-2009.
Reduction rate of air resistance (%) = [(initial air resistance) - (air resistance after water resistance test)] / (initial air resistance) x 100

The laminate preferably has an air resistance after the water resistance test of 3000 seconds/100 cc or more, more preferably 4000 seconds/100 cc or more, still more preferably 4000 seconds/100 cc or more, and still more preferably 5000 seconds/100 cc or more. Since the laminate is excellent in water resistance and moisture permeability, it can be configured to have an air resistance of 3000 seconds/100 cc or more after the water resistance test.

The laminate can be produced by forming the moisture-permeable film on at least one surface of a porous substrate by a known or commonly used method. For example, the moisture-permeable membrane may be directly formed on one surface of the porous substrate, or once the moisture-permeable membrane is formed on another support, the moisture-permeable membrane may be formed on one surface of the porous substrate. The moisture-permeable film may be formed on the porous substrate by transferring (bonding) to the porous substrate. Among them, the former method is preferable from the viewpoint of excellent adhesion between the moisture-permeable film and the porous substrate.

Hydrophilic treatment may be applied to the surface of the porous substrate on which the moisture-permeable membrane is provided. Examples of the hydrophilic treatment include those described above.

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

The above composition can be produced by a known or commonly used method. For example, it can be produced by dissolving or dispersing the above copolymer in a solvent and mixing additives such as preservatives as necessary. As the solvent, water and/or a water-soluble solvent are preferable. It is presumed that when water or a water-soluble solvent is used, the above copolymer will be dispersed in the composition in a core-shell shape with a hydrophobic portion on the inside and a hydrophilic portion on the outside. By using such a composition, when the coating film is dried, the hydrophilic part and the hydrophobic part are phase-separated to form a moisture-permeable film with a water-conducting path, and the hydrophobic parts are firmly bonded to each other. It is estimated that it will be, and the water resistance will be better.

Examples of the water-soluble solvent include aliphatic water-soluble alcohols such as methanol, ethanol, n-propanol, and i-propanol; ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. and glycol ethers such as Only one type of the water-soluble solvent may be used, or two or more types may be used.

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 further It is preferably 1.5 to 3% by mass. When the concentration is 5% by mass or less, the thickness of the coating layer increases, so that the thickness of the moisture-permeable membrane after drying becomes more uniform. As a result, it is possible to form a thinner moisture-permeable film while maintaining excellent gas barrier properties, and as a result, the moisture permeability is further improved. Further, when the concentration is within the above range, it is easy to form a moisture-permeable film having excellent coatability and excellent moisture permeability and gas barrier properties.

In addition, you may utilize the well-known coating method for application|coating of the said composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters and direct coaters may be used.

The heating temperature for removing the solvent from the coating film is preferably 35 to 90°C, more preferably 40 to 85°C, and still more preferably 45 to 80°C. The heating time may be appropriately selected, and is, for example, 5 seconds to 20 minutes, preferably 5 seconds to 10 minutes, more preferably 10 seconds to 5 minutes. A polyolefin resin that can be easily formed into a moisture-permeable film at a low temperature of 90° C. or lower (especially 80° C. or lower) using the above composition and has excellent moisture permeability as a porous substrate. can be used.

The laminate has low air permeability and excellent moisture permeability. Furthermore, it is also excellent in moisture permeability and water resistance in a low-temperature, low-humidity environment. For this reason, the laminate is used in products that require such functions, such as total heat exchangers, innerwear for clothes, disposable water-repellent and moisture-permeable materials, and applications for dehydration without being exposed to air or bacteria ( It can be preferably used for a filter for preserving aged meat, etc.). The laminate for the total heat exchange device is, for example, a sheet capable of exchanging temperature (sensible heat) and humidity (latent heat) between supply air and exhaust air. Moreover, when the laminate has a structure in which a hydrophilic portion and a hydrophobic portion are phase-separated, it can also be used as a barrier film having moisture permeability. When the diameter of the hydrophilic portion is small, the moisture-permeable barrier film allows small-sized hydrophilic substances (such as water vapor) to pass through the hydrophilic portion, but does not allow large-sized substances (such as viruses) to pass through. , the two can be separated.

A total heat exchange device (total heat exchange sheet) can be obtained by deforming the laminate into a corrugated shape as necessary and further laminating the laminate. The total heat exchange device may be either a cross-flow type or a counter-flow type. A total heat exchanger using the laminate has low air permeability and is excellent in moisture permeability (especially in a low temperature and low humidity environment) and water resistance. The above total heat exchange device can be used as a total heat exchange device for an air conditioner. The air conditioner has low air permeability, excellent moisture permeability, and a total heat exchange device that is excellent in moisture permeability and water resistance in a low-temperature and low-humidity environment. Excellent durability even in low-temperature, low-humidity environments.

Each aspect disclosed in this specification may be combined with any other feature disclosed in this specification. Each configuration and combination thereof in each embodiment is an example, and addition, omission, replacement, and other changes of configuration are possible as appropriate without departing from the gist of the present disclosure. In addition, each invention according to the present disclosure is not limited by the embodiments or the following examples, but only by the claims.

An embodiment of the present disclosure will be described in more detail below based on examples.

Example 1
A random copolymer of 2-methacryloyloxyethylphosphorylcholine and stearyl methacrylate (constituent unit ratio [former/latter]: 1/1, concentration: 4% by mass, weight average molecular weight: 100,000) and a preservative are mixed, Diluted with distilled water to obtain a composition having a copolymer concentration of 2% by mass (the copolymer is the main component in the solid content). On the other hand, one surface of a polyolefin resin porous substrate (thickness: 20 μm, surface tension: 32 dyn) was subjected to corona treatment to form a hydrophilic surface with a surface tension of 46 dyn. Then, the composition was applied to the hydrophilic surface of the porous substrate using an applicator and heated at 50° C. for 3 minutes to form a moisture permeable film (thickness: 100 to 500 nm). Thus, the laminate of Example 1 was produced.

Example 2
A laminate of Example 2 was produced in the same manner as in Example 1 except that a polyolefin resin porous substrate (thickness: 12 μm, surface tension: 32 dyn) was used as the porous substrate.

Example 3
A laminate of Example 3 was produced in the same manner as in Example 1, except that a polyolefin resin porous substrate (thickness: 25 μm, surface tension: 32 dyn) was used as the porous substrate.

Example 4
A laminate of Example 4 was produced in the same manner as in Example 1 except that a polyolefin resin porous substrate (thickness: 5 μm, surface tension: 32 dyn) was used as the porous substrate.

Example 5
A random copolymer of 2-methacryloyloxyethylphosphorylcholine and stearyl methacrylate (constituent unit ratio [former/latter]: 1/1, concentration: 4% by mass, weight average molecular weight: 100,000) and a preservative are mixed, Diluted with distilled water to obtain a composition having a copolymer concentration of 1.5% by mass (the copolymer is the main component in the solid content). Then, a laminate of Example 5 was produced in the same manner as in Example 1 except that the composition was used to form a moisture permeable film.

Example 6
Random copolymer of 3-[2-(methacryloyloxy)ethyl]dimethylammonium propionate and lauryl acrylate (constituent unit ratio [former/latter]: 40/60, concentration: 10% by mass, weight average molecular weight: 80000) and a preservative, and diluted with distilled water to obtain a composition having a copolymer concentration of 4% by mass (the copolymer is the main component in the solid content). Then, a laminate of Example 6 was produced in the same manner as in Example 1, except that the composition was used to form a moisture-permeable film.

Example 7
Random copolymer of 3-[(2-methacryloylamino)propyl]dimethyl-3-sulfobutylammonium hydroxide salt and N-dodecylmethacrylamide (constituent unit ratio [former/latter]: 30/70, concentration: 50 % by mass, weight average molecular weight: 80000) and a preservative, and diluted with distilled water to obtain a composition with a copolymer concentration of 2% by mass (the copolymer is the main component in the solid content). Then, a laminate of Example 7 was produced in the same manner as in Example 1, except that the composition was used to form a moisture-permeable film.

Comparative example 1
A total heat exchange sheet contained in a commercially available total heat exchanger was taken out and used as a laminate in Comparative Example 1. The laminate is obtained by using paper (thickness: 40 μm) as a porous substrate and impregnating the porous substrate with a deliquescent inorganic salt as a moisture permeability improving component.

Comparative example 2
Polyurethane-based resin solution (trade name “Sampren H-600”, manufactured by Sanyo Chemical Industries, Ltd., concentration: 8% by mass) is applied on paper using an applicator, heated at 120 ° C. for 3 minutes, and moisture permeable. A film was formed. Thus, a laminate of Comparative Example 2 was produced.

(evaluation)
Each laminate obtained in Examples and Comparative Examples was evaluated as follows. The evaluation results are shown in the table. "-" in the table indicates that evaluation was not performed. In addition, a polyolefin resin porous base material without a moisture-permeable membrane was evaluated as Comparative Example 3.

(1) Air Resistance The air resistance of the laminates obtained in Examples was measured based on the Gurley method of JIS P8117-2009. Specifically, a test piece of 5 cm x 5 cm was cut out from each of the laminates obtained in Examples and Comparative Examples, and was subjected to a Gurley apparatus, and the number of seconds in which 100 cc of air flowed was measured with a stopwatch.

(2) Moisture Permeability The laminates obtained in Examples and Comparative Examples were measured for moisture permeability based on the moisture permeability test method (cup method) of JIS Z0208-1976. Specifically, after the laminates obtained in Examples and Comparative Examples were allowed to stand in the measurement environment for 2 hours or more, the moisture-permeable cup was covered with a moisture-permeable sheet to be airtight. Then, in an environment with virtually no wind (wind speed of 0.2 m/s or less), the increase in the total mass of calcium chloride and the moisture permeable cup after 1 hour is converted into the mass per 1 m ² of the test piece for 24 hours. and measured as moisture permeability. The measurement was carried out under two environments: a temperature of 20° C. and a relative humidity of 65%, and a temperature of 5° C. and a relative humidity of 45%.

(3) Maximum Diameter of Hydrophilic Portion For the laminates obtained in Examples and Comparative Examples, images of the surface of the moisture-permeable membrane were measured for adhesive force with a scanning probe microscope (SPM) (model number “Dimension Icon”, manufactured by Bruker). Using the mode, the area with high adsorption force (hydrophilic area) and the area with low adsorption force (hydrophobic area) are quantified by the adhesive force, and processed with image analysis software to calculate the size of the hydrophilic area as a circle equivalent diameter. and the maximum diameter of the hydrophilic portion was calculated.

The laminates of Examples were evaluated to have high air resistance, that is, low air permeability and excellent moisture permeability. In particular, the moisture permeability was 500 g/(m ² ·24 h) or more in an environment of a temperature of 5°C and a relative humidity of 45% (Examples 1 to 3), and the moisture permeability in a low-temperature and low-humidity environment was evaluated as excellent. On the other hand, the laminate of Comparative Example 1 was evaluated as inferior in moisture permeability. In addition, the laminate of Comparative Example 2 was evaluated as having high air permeability and poor moisture permeability. Further, Comparative Example 3 using only the porous base material was excellent in moisture permeability, but had high air permeability.

Variations of the invention according to the present disclosure are described below.
[Appendix 1] A porous substrate and a moisture-permeable membrane provided on at least one surface of the porous substrate, wherein the moisture-permeable membrane has a side chain containing a betaine group as a functional group. A laminate formed from a plastic copolymer.
[Appendix 2] The laminate according to Appendix 1, wherein the copolymer includes a structural unit represented by the formula (1) as a structural unit having a side chain containing a betaine group.
[Appendix 3] The laminate according to Appendix 1 or 2, wherein the copolymer further has a hydrophobic functional group in a side chain.
[Appendix 4] The laminate according to Appendix 3, wherein the copolymer includes a structural unit represented by the formula (2) as a structural unit having the hydrophobic functional group in a side chain.
[Appendix 5] In Appendix 4, wherein the molar ratio of the structural unit represented by the formula (1) in the copolymer to the structural unit represented by the formula (2) is 1/100 to 100/1 Laminate as described.
[Appendix 6] The laminate according to Appendix 4 or 5, wherein R ¹ in the formula (1) is a hydrogen atom or a methyl group (preferably a methyl group).
[Appendix 7] The laminate according to any one of Appendices 4 to 6, wherein the structural unit represented by the formula (1) is a structural unit derived from an acrylic acid ester or a methacrylic acid ester.
[Appendix 8] In 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). A laminate according to any one of the above.
[Appendix 9] Any one of Appendices 4 to 8, wherein Y is an alkylene group having 1 to 4 carbon atoms (preferably a linear alkylene group having 1 to 4 carbon atoms) in the formula (1). laminate.
[Appendix 10] The laminate according to any one of Appendices 4 to 9, wherein the cation in the formula (1) is an ammonium ion.
[Appendix 11] The laminate according to any one of Appendices 4 to 10, wherein the anion in the formula (1) is a phosphate ion, a sulfate ion, or a carbonate ion.
[Appendix 12] The formula (1) is a group represented by the formula (1-1), a group represented by the formula (1-2), or a group represented by the following formula (1-3) The laminate according to any one of Appendices 4 to 11, comprising
[Appendix 13] The laminate according to Appendix 12, wherein R ⁵ , R ⁶ and R ⁷ in the formula (1-1) are methyl groups.
[Appendix 14] The laminate according to Appendix 12 or 13, wherein X is a dimethylene group and Y is a dimethylene group in the formula (1-1).
[Appendix 15] The laminate according to any one of Appendices 12 to 14, wherein the monomer forming the structural unit represented by formula (1-1) is 2-methacryloyloxyethylphosphorylcholine.

[Appendix 16] The laminate according to Appendix 12, wherein in the formula (1-2), R ⁸ and R ⁹ are methyl groups.
[Appendix 17] The laminate according to Appendix 12 or 16, wherein X is a trimethylene group and Y is a tetramethylene group in the formula (1-2).
[Appendix 18] The laminate according to appendix 12, wherein in the formula (1-3), R ⁸ and R ⁹ are methyl groups.
[Appendix 19] The laminate according to Appendix 12 or 18, wherein X is a dimethylene group and Y is a methylene group in the formula (1-3).
[Appendix 20] The laminate according to any one of Appendices 4 to 19, wherein R ² in the formula (2) is a hydrogen atom or a methyl group (preferably a methyl group).
[Appendix 21] In the above formula (2), R ³ is a hydrocarbon group (preferably aliphatic 20. The laminate according to any one of Appendices 4 to 20, which is a hydrocarbon group, more preferably a straight or branched chain alkyl group, more preferably a straight chain alkyl group.
[Appendix 22] The laminate according to any one of Appendices 4 to 21, wherein the monomer forming the structural unit represented by formula (2) is stearyl (meth)acrylate.

[Appendix 23] The molar ratio [former/latter] of the hydrophilic portion to the hydrophobic portion in the copolymer is 0.01 to 2.0 (preferably 0.01 to 1.5, more preferably 0.01 to 1.5). 3) The laminate according to any one of Appendices 4 to 22.
[Appendix 24] The molar ratio [former/latter] of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) is 0.01 to 90 (preferably 0.02 to 80 , more preferably 0.1 to 20, more preferably 0.5 to 5).
[Appendix 25] The total number of moles of the structural unit represented by the formula (1) and the structural unit represented by the formula (2) is the total number of moles of the structural units derived from all the monomers constituting the copolymer. 25. The laminate according to any one of appendices 4 to 24, which is 50 mol% or more (preferably 90 mol%, more preferably 99 mol% or more) relative to the total number of moles.
[Appendix 26] The copolymer has a weight average molecular weight of 20,000 to 2,000,000 (preferably 30,000 to 1,500,000, more preferably 50,000 to 1,000,000, more preferably 70,000 to 500,000). 26. The laminate according to any one of 25.
[Appendix 27] 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). 27. The laminate according to any one of appendices 4 to 26, which is coalesced.
[Appendix 28] Any one of Appendices 1 to 27, wherein the surface of the moisture permeable membrane has a structure in which a hydrophilic portion and a hydrophobic portion are phase-separated, and the maximum diameter of the hydrophilic portion on the surface of the moisture permeable membrane is 50 nm or less. The laminate according to 1.
[Appendix 29] The laminate according to any one of Appendices 1 to 28, wherein the moisture permeable membrane contains a preservative having a diameter smaller than the thickness of the moisture permeable membrane.

[Appendix 30] The laminate according to any one of Appendices 1 to 29, wherein the material forming the porous substrate is a hydrophobic material (preferably polyolefin resin, more preferably polypropylene resin).
[Appendix 31] The laminate according to any one of Appendices 1 to 30, wherein the porosity of the porous substrate is 30 to 90% by volume (preferably 40 to 70% by volume).
[Appendix 32] The laminate according to any one of Appendices 1 to 31, wherein the porous substrate has a surface on which the moisture-permeable membrane is provided is subjected to a hydrophilic treatment.
[Appendix 33] Any one of Appendices 1 to 32, wherein the surface tension of the surface of the porous substrate on which the moisture permeable membrane is formed is 35 to 55 dyn/cm (preferably 37 to 50 dyn/cm) Laminate as described.
[Appendix 34] Any one of Appendices 1 to 33, wherein the internal surface tension of the region of the porous substrate where the moisture-permeable membrane is not formed is less than 35 dyn/cm (preferably 33 dyn/cm or less). The laminate according to .

[Appendix 35] Based on the moisture permeability test method of JIS Z0208-1976, the moisture permeability under the conditions of temperature 20 ° C., relative humidity 65%, wind speed 0.2 m / sec or less is 1600 g / (m ² 24 h) or more (preferably 35. The laminate according to any one of appendices 1 to 34, which is 1700 g/(m ² ·24 h) or more, more preferably 1800 g/(m ² ·24 h) or more).
[Appendix 36] Based on the moisture permeability test method of JIS Z0208-1976, the moisture permeability under the conditions of temperature 5 ° C., relative humidity 45%, wind speed 0.2 m / s or less is 300 g / (m ² · 24 h) or more (preferably 400 g/(m ² ·24 h) or more, more preferably 500 g/(m ² ·24 h) or more).
[Appendix 37] Any one of Appendices 1 to 36, wherein the air permeability resistance based on the Gurley method of JIS P8117-2009 is 3000 seconds/100 cc or more (preferably 4000 seconds/100 cc or more, more preferably 5000 seconds/100 cc or more). 1. Laminate according to one.
[Appendix 38] Any one of Appendices 1 to 37, wherein the rate of decrease in air resistance in the following water resistance test is 50% or less (preferably 20% or less, more preferably 15% or less). laminate.
<Water resistance test>
A test piece with a diameter of 7 cm is cut out from the laminate, and the air resistance is measured (initial air resistance). After that, the test piece is immersed in room temperature water for 15 minutes, and then naturally dried at room temperature. For the above test piece, this immersion and drying cycle is repeated 50 times to obtain a test piece after the water resistance test. Then, the air resistance of the obtained test piece after the water resistance test is measured (air resistance after the water resistance test). Then, the rate of decrease in air resistance is obtained from the following formula. Both the initial air resistance and the air resistance after the water resistance test are based on the Gurley method of JIS P8117-2009.
Reduction rate of air resistance (%) = [(initial air resistance) - (air resistance after water resistance test)] / (initial air resistance) x 100
[Appendix 39] The air resistance after the following water resistance test based on the Gurley method of JIS P8117-2009 is 3000 seconds/100 cc or more (preferably 4000 seconds/100 cc or more, more preferably 5000 seconds/100 cc or more). The laminate according to any one of Appendices 1 to 38.
<Water resistance test>
A test piece with a diameter of 7 cm is cut out from the laminate, immersed in room temperature water for 15 minutes, and then naturally dried at room temperature. For the test piece, this immersion and drying cycle is repeated 50 times to obtain a test piece after the water resistance test. Then, the air permeability resistance of the obtained test piece after the water resistance test is measured.

1 Laminate 11 Porous substrate 11a One surface of porous substrate 12 Moisture-permeable membrane

Claims (9)

comprising a porous substrate and a moisture-permeable membrane provided on at least one surface of the porous substrate;
The moisture-permeable membrane is formed from a thermoplastic copolymer having a side chain containing a betaine group as a functional group ,
The copolymer has a structural unit represented by the following formula (1) as a structural unit having a side chain containing a betaine group, and a structural unit having a hydrophobic functional group in a side chain represented by the following formula (2). Formed from a copolymer in which the molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) is 1/100 to 100/1 laminated .

[In formula (1), R ¹ represents a hydrogen atom or 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. Z ¹ represents O or NH. α and β represent a combination of cations and anions. ]

[In formula (2), R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ represents a hydrocarbon group having 2 or more carbon atoms. Z ² represents O or NH. ] 2. The laminate according to claim 1 , wherein the cation in formula (1) is an ammonium ion. 3. The laminate according to claim 1, wherein the anion in the formula (1) is a phosphate ion, a sulfate ion, or a carbonate ion. wherein the formula (1) comprises a group represented by the following formula (1-1), a group represented by the following formula (1-2), or a group represented by the following formula (1-3); The laminate according to any one of Items 1 to 3 .

[In formulas (1-1) to (1-3), X and Y are the same as above, and the left bond of the carbonyl carbon atom is bonded to the carbon atom having R ¹ in formula (1). In formula (1-1), R ⁵ , R ⁶ and R ⁷ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. In formulas (1-2) and (1-3), R ⁸ and R ⁹ are the same or different and represent an alkyl group having 1 to 4 carbon atoms. ] The laminate according to any one of claims 1 to 4 , wherein the copolymer has a weight average molecular weight of 20,000 to 2,000,000. 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). The laminate according to any one of claims 1-5 . The laminate according to any one of claims 1 to 6 , wherein the porous substrate has a surface on which the moisture-permeable membrane is provided is subjected to a hydrophilic treatment. According to the moisture permeability test method of JIS Z0208-1976, the moisture permeability is 1600 g / (m ² · 24 h) or more under the conditions of a temperature of 20 ° C., a relative humidity of 65%, and a wind speed of 0.2 m / sec or less. 8. The laminate according to any one of 7 . 9. The moisture permeable membrane surface according to any one of claims 1 to 8 , wherein the surface of the moisture permeable membrane has a structure in which a hydrophilic portion and a hydrophobic portion are phase-separated, and the maximum diameter of the hydrophilic portion on the surface of the moisture permeable membrane is 50 nm or less. laminate.

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