Moisture-permeable airtight sheet

Abstract

To provide a moisture-permeable airtight sheet that maintains airtightness, adjusts humidity permeability according to the amount of moisture in the air to prevent condensation within the wall structure, possesses excellent mechanical strength, has moisture permeability more suitable for hot and humid climates, and can withstand forces applied in the direction of delamination during, for example, positioning or re-installation work, and can withstand temperature changes between day and night, thus maintaining long-term quality. [Solution] Basis weight 20g / m 2 More than 100g / m 2 A moisture-permeable airtight sheet comprising a base layer made of the following nonwoven fabric, and a moisture-permeable resin layer on at least one side of the base layer, wherein a breathable olefin-based hot-melt adhesive layer is provided between the base layer and the moisture-permeable resin layer, the moisture-permeable resin layer comprising an ethylene-vinyl alcohol copolymer resin.

Description

Technical Field

[0001] The present invention relates to a moisture-permeable and airtight sheet.

Background Art

[0002] In response to the appearance of internal condensation (so-called winter-type condensation) in the filled heat-insulating outer wall of a wooden frame structure building, a moisture-proof layer such as a polyethylene sheet is applied to the indoor-side surface of the wall structure for the purpose of suppressing the intrusion of water vapor into the heat-insulating material. Further, for the purpose of quickly discharging the moisture that has invaded the wall structure to the outside, a ventilation method in which a ventilation layer and a moisture-permeable waterproof sheet are installed in the wall structure has become a standard method.

[0003] On the other hand, with the spread of air-conditioning equipment in houses, in hot and humid regions, in summer, there is a problem of internal condensation (so-called summer-type condensation) in which the moisture that has invaded the heat-insulating material from the outside through the ventilation layer condenses on the air-conditioned indoor side. In an attempt to solve this problem, there is a method that uses a conventional moisture-permeable waterproof sheet with a high moisture-permeability resistance value for the moisture-proof layer, but still, condensation occurs in the wall structure during the high-temperature and high-humidity period from the rainy season to summer in hot and humid areas.

[0004] Under such circumstances, a functional sheet whose moisture-permeable performance changes according to the environmental humidity has been developed for the purpose of actively preventing internal condensation. In Patent Document 1, a base material layer made of a spunbonded thermoplastic long fiber non-woven fabric with a basis weight of 20 g / m 2 or more and 100 g / m 2 or less, and a moisture-permeable resin layer on at least one surface of the base material layer are provided. The crimping area ratio of the thermoplastic long fiber non-woven fabric is 6% or more and 40% or less of the area of the thermoplastic long fiber non-woven fabric, and the moisture-permeable resin layer contains an ethylene-vinyl alcohol copolymer resin, and a moisture-permeable and airtight sheet has been proposed. This moisture-permeable and airtight sheet has a low-humidity moisture-permeability resistance value of 10 m 2 ·s·Pa / μg or more and less than 300 m 2 ·s·Pa / μg when measured in accordance with JIS-A-1324 under the environment of 23°C and 50%RH, and a high-humidity moisture-permeability resistance value of 3 m when measured in accordance with JIS-L-1099A-1 under the environment of 40°C and 90%RH.2 ·s·Pa / μg or more 30m 2 It is less than s·Pa / μg. It is explained that by using this moisture-permeable airtight sheet, it is possible to gradually lower the water vapor pressure within the wall structure from the inside to the outside, thereby creating a humidity gradient, so that the humidity difference between the inside and outside gradually equalizes. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-020829 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, while the moisture-permeable airtight sheet described in Patent Document 1 has humidity control performance suited to the Japanese climate better than that of Europe and the United States, in Japan, which is becoming subtropical, a moisture-permeable airtight sheet more suitable for the hot and humid climate is needed. In this regard, the moisture-permeable airtight sheet has high moisture resistance around RH, with relative humidity between 60% and 65%, and its humidity control performance at moderate humidity is insufficient. Furthermore, although the moisture-permeable airtight sheet has mechanical strength, there are problems with the lamination strength between the base material layer and the moisture-permeable resin layer, leading to problems such as delamination during positioning during work or during re-application. Moreover, the moisture-permeable airtight sheet may experience delamination due to differences in the shrinkage rate of the base material in response to temperature changes between day and night, posing a problem for long-term quality maintenance.

[0007] Therefore, there is a strong demand for a breathable, airtight sheet that combines breathability suitable for hot and humid climates with mechanical strength, and also has high laminate strength, making it less prone to problems in terms of workability and less susceptible to long-term quality deterioration.

[0008] An object of the present invention is to maintain airtightness, adjust humidity permeation according to the moisture content in the air, prevent the occurrence of dew condensation in the wall structure, have excellent mechanical strength, have moisture permeability suitable for a more steaming climate, and moreover, for example, during alignment during work or during re-stretching work, be able to withstand the force applied in the delamination direction and be able to withstand the temperature change between day and night, thereby having long-term quality maintenance, and provide a moisture-permeable airtight sheet.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a moisture-permeable airtight sheet having a specific structure can solve the above problems, and have completed the present invention.

[0010] That is, the present invention is as follows. [1] A base material layer made of a non-woven fabric with a basis weight of 20 g / m 2 or more and 100 g / m 2 or less, and a moisture-permeable resin layer on at least one surface of the base material layer, and including an olefin-based hot melt adhesive layer having air permeability between the base material layer and the moisture-permeable resin layer, a moisture-permeable airtight sheet, wherein the moisture-permeable resin layer contains an ethylene-vinyl alcohol copolymer resin.

[0011] [2] Measured in accordance with ISO12572:2016 and numerically converted from the moisture permeation resistance calculation method of JIS-A-1324, the low humidity moisture permeation resistance value under the conditions of 23°C and 25%RH (23°C and 0%RH inside the moisture permeation cup, 23°C and 50%RH in the external environment) is 82 m 2 ·s·Pa / μg or more and 500 m 2 ·s·Pa / μg or less, and measured in accordance with ISO12572:2016 and numerically converted from the moisture permeation resistance calculation method of JIS-A-1324, the medium humidity moisture permeation resistance value under the conditions of 23°C and 62.5%RH (23°C and 75%RH inside the moisture permeation cup, 23°C and 50%RH in the external environment) is 30 m 2 ·s·Pa / μg or more and 70 m 2The high-humidity water vapor permeability resistance value is less than or equal to s·Pa / μg, measured in accordance with ISO12572:2016, and numerically converted from the water vapor permeability resistance calculation method of JIS-A-1324, under conditions of 23°C and 90%RH (23°C and 100%RH inside the water vapor permeability cup, 23°C and 80%RH outside environment) of 1 m 2 ·s·Pa / μg or more 20m 2 A moisture-permeable airtight sheet as described in [1], wherein the g / m² is s·Pa / μg or less. [Effects of the Invention]

[0012] The moisture-permeable airtight sheet of the present invention possesses excellent mechanical strength and variable properties that allow humidity permeation to be adjusted according to the amount of moisture in the air while maintaining airtightness. Therefore, even when installed in a wall structure as a functional sheet, it is difficult to damage and can effectively prevent condensation from occurring within the wall structure. Furthermore, because the moisture-permeable airtight sheet of the present invention has high laminate strength, using it allows for multiple reapplication operations during construction, for example, and effectively prevents delamination due to temperature differences between day and night, thus maintaining long-term quality. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a digital photograph showing the moisture-permeable airtight sheet obtained in Example 2 after a peel test. [Figure 2] Figure 2 is a digital photograph showing the sheet after a peel test of the moisture-permeable airtight sheet obtained in Comparative Example 1. [Modes for carrying out the invention]

[0014] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment.

[0015] [Moisture-permeable airtight sheet] The moisture-permeable airtight sheet of this embodiment has a basis weight of 20 g / m². 2 More than 100g / m2 The material comprises a base layer made of the following nonwoven fabric, and a moisture-permeable resin layer on at least one side of the base layer, with a breathable olefin-based hot-melt adhesive layer between the base layer and the moisture-permeable resin layer, the moisture-permeable resin layer comprising an ethylene-vinyl alcohol copolymer resin.

[0016] [Base material layer] The moisture-permeable airtight sheet of this embodiment includes a base layer. The base layer has a basis weight of 20 g / m². 2 More than 100g / m 2 It consists of the following nonwoven fabrics.

[0017] (Non-woven fabric) Examples of fibers constituting the nonwoven fabric for the moisture-permeable airtight sheet include polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polyethylene isophthalate, copolymer polyester, polylactic acid, polybutylene succinate, polyethylene succinate, and aliphatic polyester; polyolefin fibers such as polyethylene (high-density polyethylene and low-density polyethylene), polypropylene, and ethylene-propylene copolymer; polyamide fibers such as nylon 6, nylon 66, nylon 610, copolymer nylon, and nylon 612; and heat-resistant fibers such as polybenzazole fiber (PBO), polyphenylene sulfide fiber (PPS), polyimide fiber (PI), fluorine fiber, and polyetheretherketone fiber (PEEK). These fibers can be used individually, or two or more fibers can be mixed in any ratio to form a composite fiber according to the required specifications.

[0018] Examples of composite fibers include core-sheath composite fibers and side-by-side composite fibers. Examples of core-sheath composite fibers include composite fibers in which the core is made of a high-melting-point resin and the sheath is made of a low-melting-point resin.

[0019] Examples of high-melting-point resins include polyethylene terephthalate, polybutylene terephthalate, copolymer polyester, nylon 6, and nylon 66. These high-melting-point resins may be included individually or in combination of two or more types.

[0020] Examples of low-melting-point resins include low-density polyethylene, high-density polyethylene, polypropylene copolymer polyethylene, copolymer polypropylene, copolymer polyester, and aliphatic polyester. These low-melting-point resins may be included individually or in combination of two or more types.

[0021] The fibers constituting the nonwoven fabric preferably include polyolefin fibers, and more preferably polyolefin filament fibers. Examples of polyolefin filament fibers include polyethylene, polypropylene, and copolymers of ethylene and / or propylene with other α-olefins. Examples of other α-olefins include α-olefins having 4 to 10 carbon atoms. Examples of α-olefins having 4 to 10 carbon atoms include 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene, and 1-octene. These α-olefins may be included individually or in combination of two or more types.

[0022] Among these, polyethylene is preferable because it offers greater strength, is less prone to breakage during use, and exhibits superior dimensional stability during production. Furthermore, when polyethylene is used as the sheath in a core-sheath structure, the nonwoven fabric having that structure tends to have superior resistance to thermal degradation and alkali resistance.

[0023] The basis weight of the nonwoven fabric is 20 g / m². 2 More than 110g / m 2 The following is preferred: 25 g / m² 2 More than 100g / m 2 The following is more preferable: 30 g / m² 2 More than 95g / m 2The following is more preferably 35 g / m² 2 More than 90g / m 2 The following applies: The weight is 20g / m². 2 When the material meets these specifications, the mechanical strength of the nonwoven fabric as a moisture-permeable airtight sheet improves, making it less prone to tearing. Furthermore, when printing text or designs onto the nonwoven fabric, the ink becomes less likely to pass through the fabric, resulting in more favorable printing. (Basis weight: 110 g / m²) 2 The following conditions tend to result in a breathable airtight sheet with excellent flexibility and workability. In this specification, the basis weight of a nonwoven fabric or breathable airtight sheet is determined, for example, by cutting the nonwoven fabric or breathable airtight sheet to a predetermined area, measuring its mass, and taking that value per 1 m 2 It can be calculated by converting it to a unit of mass. For specific measurement methods, please refer to the examples.

[0024] Nonwoven fabrics can be obtained by known methods. Examples of such methods include the dry method, the wet method, the spunbond method, the meltplane method, and the airlaid method. Methods for bonding the fibers of nonwoven fabrics obtained by these methods include the chemical bonding method, the thermal bonding method, the needle punching method, and the water entanglement method.

[0025] The nonwoven fabric may be embossed. Examples of embossed shapes include circular, rhombus, square, and elliptical shapes.

[0026] Commercially available nonwoven fabrics may be used. Examples of such commercially available products include the Marix® series, the Elves® series, and the Elves®-II series (all manufactured by Unitika Ltd.), as well as 6640-1A (product name, spunbond nonwoven fabric) and 9724-F (product name, spunbond nonwoven fabric) (both manufactured by Shinwa Co., Ltd.).

[0027] [Olefin-based hot melt adhesive layer] The moisture-permeable airtight sheet of this embodiment includes an olefin-based hot-melt adhesive layer that has breathability between the base material layer and the moisture-permeable resin layer.

[0028] In this specification, "having breathability" means having the property of being permeable to gas.

[0029] In this embodiment, the adhesive layer is formed by applying an olefin-based hot-melt adhesive between the substrate layer and the moisture-permeable resin layer so that the olefin-based hot-melt adhesive layer is permeable in the thickness direction of the moisture-permeable airtight sheet. Furthermore, the olefin-based hot-melt adhesive impregnates both the substrate layer and the moisture-permeable resin layer, exhibiting an anchoring effect. As a result, the moisture-permeable airtight sheet is less prone to lifting or partial delamination at the lamination interface and is well integrated as a sheet. For the method of applying the adhesive, refer to, for example, the manufacturing method and examples of the moisture-permeable airtight sheet described later.

[0030] The lamination strength between the base layer and the moisture-permeable resin layer is preferably 2N / 50mm or higher. The interposition of an olefin-based hot-melt adhesive layer integrates the base layer and the moisture-permeable resin layer while maintaining breathability, resulting in sufficient mechanical strength and functionality as a moisture-permeable airtight sheet. Therefore, the moisture-permeable airtight sheet can withstand forces applied in the delamination direction during, for example, positioning or re-application work, and can also withstand temperature changes between day and night, thus maintaining long-term quality.

[0031] Examples of olefin-based hot melt adhesives include polyolefin elastomers such as ethylene-propylene copolymer and its elastomer, ethylene-α-olefin copolymer, styrene-butadiene copolymer (SBR) and its hydride, styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS); ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butyl acrylate. Examples of polyolefin-based hot melt adhesives include acrylate copolymers, ethylene-methacrylic acid copolymers, ethylene-maleic anhydride copolymers, ethylene-ethyl acrylate-maleic anhydride copolymers, ethylene-glycidyl methacrylate copolymers, ethylene-vinyl acetate copolymers, ethylene-glycidyl methacrylate-vinyl acetate copolymers, ethylene-glycidyl methacrylate-methyl acrylate copolymers, ethylene-methacrylic acid-maleic anhydride copolymers, ethylene-glycidyl methacrylate-vinyl acetate copolymers, maleic anhydride-grafted polypropylene, maleic anhydride-grafted ethylene-vinyl acetate copolymers, maleic anhydride-grafted polyethylene, and other polyolefin-based hot melt adhesives; polyamide-based elastomers; and modified versions thereof. These olefin-based hot melt adhesives may be used individually or in combination of two or more types.

[0032] Commercially available olefin-based hot melt adhesives may be used. Examples of such commercially available products include Evergrip® AS896 (trade name, modified olefin-based, manufactured by Toagosei Co., Ltd.), Evergrip® PK222 (trade name, ethylene-vinyl acetate copolymer adhesive, manufactured by Toagosei Co., Ltd.), Evergrip® 292 (trade name, ethylene-vinyl acetate copolymer adhesive, manufactured by Toagosei Co., Ltd.), and Evergrip® EV165 (trade name, olefin-based hot melt adhesive, manufactured by Toagosei Co., Ltd.).

[0033] [Moisture-permeable resin layer] The moisture-permeable airtight sheet of this embodiment includes a moisture-permeable resin layer on at least one side of the base layer. The moisture-permeable resin layer includes an ethylene-vinyl alcohol copolymer resin. The moisture-permeable resin layer may further contain, together with the ethylene-vinyl alcohol copolymer resin, one or more selected from the group consisting of ethylene-vinyl acetate copolymer saponified resin and ethylene-vinyl acetate copolymer resin.

[0034] (Ethylene-vinyl alcohol copolymer resin) Ethylene-vinyl alcohol copolymer resin is a copolymer containing an ethylene monomer and a vinyl alcohol monomer. The ethylene-vinyl alcohol copolymer resin may also be a copolymer containing monomers other than these monomers. By including the ethylene-vinyl alcohol copolymer resin in the moisture-permeable resin layer, the moisture-permeable resin layer can adjust humidity transmission according to the amount of moisture in the air while maintaining airtightness. This prevents condensation from occurring within the wall structure and provides moisture permeability that is more suitable for hot and humid climates.

[0035] Other monomers include, for example, α-olefins such as propylene, isobutene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene; hydroxyl group-containing α-olefins such as 3-buten-1-ol, 4-penten-1-ol, and 3-buten-1,2-diol; hydroxyl group-containing α-olefin derivatives such as esterified and acylated α-olefins; unsaturated carboxylic acids or their salts; partially alkyl esters of unsaturated polycarboxylic acids; fully alkyl esters of unsaturated polycarboxylic acids; unsaturated carboxylic acid nitriles; unsaturated carboxylic acid amides; unsaturated carboxylic acid anhydrides; unsaturated sulfonic acids or their salts; vinylsilane compounds; vinyl acetate, (meth)acrylic acid esters; vinyl fluoride; vinylidene fluoride; vinyl chloride; vinylidene chloride; carbon monoxide; acrylonitrile; and styrene.

[0036] The ethylene-vinyl alcohol copolymer resin may be an ethylene-vinyl alcohol copolymer having a 1,2-glycol bond as a partial structure; an ethylene-vinyl alcohol copolymer partially modified with a compound that can react with a hydroxyl group, such as butyraldehyde; an ethylene-vinyl alcohol copolymer resin that has undergone post-modification such as urethaneization, acetalization, cyanoethylation, or oxyalkyleneization; or an ethylene-vinyl alcohol copolymer modified with a functional group such as an acid anhydride.

[0037] Ethylene-vinyl alcohol copolymer resins may be used individually, or two or more may be mixed in any ratio according to the required specifications. Furthermore, ethylene-vinyl alcohol copolymer resins may be blended from two or more types with different ethylene content, vinyl alcohol content, melt flow rate (MFR), melting point, and glass transition temperature.

[0038] The ethylene content of the ethylene-vinyl alcohol copolymer resin is preferably 20 mol% to 50 mol%, more preferably 22 mol% to 45 mol%, and even more preferably 24 mol% to 40 mol%, based on 100% by mass of the ethylene-vinyl alcohol copolymer resin. The vinyl alcohol content of the ethylene-vinyl alcohol copolymer resin is preferably 50 mol% to 80 mol%, more preferably 55 mol% to 78 mol%, and even more preferably 60 mol% to 76 mol%, based on 100% by mass of the ethylene-vinyl alcohol copolymer resin. When the ethylene content and vinyl alcohol content are within the above ranges, there is a tendency for a better balance between moldability and gas barrier properties in the moisture-permeable resin layer.

[0039] The melt flow rate (MFR) of the ethylene-vinyl alcohol copolymer resin is preferably 0.03 g / 10 min to 60 g / 10 min, and more preferably 0.3 g / 10 min to 30 g / 10 min. When the MFR is within the above range, the back pressure of the extruder does not become too high during molding, which tends to result in better productivity. The MFR is measured according to JIS K7210-1 at a temperature of 210°C and a load of 2.16 kg.

[0040] The melting point of the ethylene-vinyl alcohol copolymer resin can be determined according to the monomer ratio of the constituent elements, but is preferably 150°C or higher, more preferably 155°C or higher, and even more preferably 160°C or higher. The upper limit is not particularly limited, but for example, it is 200°C. When the melting point is within the above range, the moldability tends to be superior.

[0041] The glass transition temperature of an ethylene-vinyl alcohol copolymer resin can be determined according to the monomer ratio of the constituent elements, but is preferably 10°C or higher, more preferably 30°C or higher, and even more preferably 50°C or higher. The upper limit is not particularly limited, but for example, it is 70°C. When the glass transition temperature is within the above range, the processability for annealing (film annealing) tends to be superior.

[0042] In this specification, the melting point and glass transition temperature can be measured, for example, by a differential scanning calorimeter (hereinafter also referred to as "DSC").

[0043] Commercially available ethylene-vinyl alcohol copolymer resins may be used. Examples of such commercially available products include the EVAL® series (manufactured by Kuraray Co., Ltd.) and the SOANOL® series (manufactured by Mitsubishi Chemical Corporation).

[0044] The content of ethylene-vinyl alcohol copolymer resin in the moisture-permeable resin layer is preferably 5% by mass or more and 100% by mass or less, more preferably 10% by mass or more and 99% by mass or less, even more preferably 20% by mass or more and 98% by mass or less, even more preferably 30% by mass or more and 95% by mass or less, and even more preferably 40% by mass or more and 93% by mass or less, as a mass percentage of the moisture-permeable resin layer. The lower limit of the content of ethylene-vinyl alcohol copolymer resin may be 50% by mass or more, 55% by mass or more, or 60% by mass or more.

[0045] (Ethylene-vinyl acetate copolymer saponified resin) The moisture-permeable resin layer may contain ethylene-vinyl acetate copolymer saponified resin. Ethylene-vinyl acetate copolymer saponified resin has superior compatibility with ethylene-vinyl alcohol copolymer resin and tends not to impair moisture permeability. Furthermore, using ethylene-vinyl acetate copolymer saponified resin tends to improve moldability. When ethylene-vinyl acetate copolymer saponified resin is included in the moisture-permeable resin layer, the mechanical properties of the moisture-permeable resin layer tend to improve, for example, impact resistance, tensile strength, and pinhole resistance.

[0046] Ethylene-vinyl acetate copolymer saponified resins can be obtained, for example, by hydrolyzing vinyl acetate residue units in an ethylene-vinyl acetate copolymer produced by high-pressure polymerization, emulsion polymerization, or solution polymerization, and saponifying them to vinyl alcohol residue units. Hydrolysis methods include, for example, reactions using alkali or acid as catalysts. Specifically, these include homogeneous saponification, in which the ethylene-vinyl acetate copolymer is dissolved in a good solvent and the reaction is carried out in a homogeneous system; and heterogeneous saponification, in which pellets or powder of the ethylene-vinyl acetate copolymer are added to a poor solvent such as methanol or ethanol and the reaction is carried out in a heterogeneous system.

[0047] Ethylene-vinyl acetate copolymer saponified resins may be used individually, or two or more may be mixed in any ratio according to the required specifications. Furthermore, ethylene-vinyl acetate copolymer saponified resins may be used as a blend of two or more ethylene-vinyl acetate copolymer saponified resins having different degrees of saponification, densities, melting points, and melt flow rates (MFRs).

[0048] The degree of saponification of the ethylene-vinyl acetate copolymer saponified resin is preferably 50 mol% to 100 mol%. The lower limit of the degree of saponification is more preferably 60 mol% or more, even more preferably 65 mol% or more, and even more preferably 70 mol% or more. When the degree of saponification is within the above range, the compatibility with the ethylene-vinyl alcohol copolymer resin is superior, and the brittleness of the ethylene-vinyl alcohol copolymer resin tends to be more favorably improved. The back pressure of the extruder does not become too high during molding, and productivity tends to be superior. The degree of saponification can be measured according to JIS K6726.

[0049] The density of the ethylene-vinyl acetate copolymer saponified resin is preferably 940 kg / m³. 3 More than 1000kg / m 3 The following, and more preferably 950 kg / m 3 More than 970kg / m 3 The following applies: When the density falls within the above range, the material tends to have better moldability. The density can be measured by the water displacement method according to ASTM D1505.

[0050] The melting point of the ethylene-vinyl acetate copolymer saponified resin is preferably 95°C to 120°C, and more preferably 100°C to 115°C. A melting point within this range tends to result in superior moldability.

[0051] The melt flow rate (MFR) of the ethylene-vinyl acetate copolymer saponified resin is preferably 1.0 g / 10 min to 100.0 g / 10 min, and more preferably 1.5 g / 10 min to 80.0 g / 10 min. When the MFR is within the above range, the moldability tends to be superior. The MFR is measured according to JIS K7210-1 at a temperature of 190°C and a load of 2.16 kg.

[0052] Commercially available ethylene-vinyl acetate copolymer saponified resins may be used. Examples of such commercially available products include Mersen® H series (manufactured by Tosoh Corporation).

[0053] The content of ethylene-vinyl acetate copolymer saponified resin in the moisture-permeable resin layer is preferably 0 to 95% by mass, more preferably 1 to 90% by mass, even more preferably 2 to 80% by mass, even more preferably 5 to 70% by mass, and even more preferably 7 to 60% by mass, as a mass ratio to the moisture-permeable resin layer. The upper limit of the content of ethylene-vinyl acetate copolymer saponified resin may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 15% by mass or less.

[0054] (Ethylene-vinyl acetate copolymer resin) The moisture-permeable resin layer may contain ethylene-vinyl acetate copolymer resin. Ethylene-vinyl acetate copolymer resin has relatively good flexibility and superior compatibility and miscibility with ethylene-vinyl alcohol copolymer resin, which tends to improve processability.

[0055] Ethylene-vinyl acetate copolymer resin is a copolymer composed of ethylene and vinyl acetate. Ethylene-vinyl acetate copolymer resin may be used alone, or two or more types may be mixed in any ratio according to the required specifications. Furthermore, ethylene-vinyl acetate copolymer resin may be used by blending, for example, two or more ethylene-vinyl acetate copolymer resins with different ethylene and vinyl acetate content.

[0056] The ethylene content of the ethylene-vinyl acetate copolymer resin is preferably 50% to 95% by mass, and more preferably 60% to 92% by mass, based on 100% by mass of the ethylene-vinyl acetate copolymer resin. The vinyl acetate content of the ethylene-vinyl acetate copolymer resin is preferably 5% to 50% by mass, and more preferably 8% to 40% by mass, based on 100% by mass of the ethylene-vinyl acetate copolymer resin. When the ethylene content and vinyl acetate content are within the above ranges, the flexibility is improved, and the compatibility and miscibility with ethylene-vinyl alcohol copolymer resin are even better, so the processability tends to be further improved.

[0057] Commercially available ethylene-vinyl acetate copolymer resins may be used. Examples of such commercially available products include the UltraSen® series (manufactured by Tosoh Corporation), the Evaflex® series (manufactured by Mitsui DuPont Polychemical Co., Ltd.), and Suntec®-EVA (manufactured by Asahi Kasei Corporation).

[0058] The content of ethylene-vinyl acetate copolymer resin in the moisture-permeable resin layer is preferably 0 to 95% by mass, more preferably 1 to 90% by mass, even more preferably 2 to 80% by mass, even more preferably 5 to 70% by mass, and even more preferably 7 to 60% by mass, as a mass percentage of the moisture-permeable resin layer. The upper limit of the content of ethylene-vinyl acetate copolymer resin may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 15% by mass or less.

[0059] (Additives) The moisture-permeable resin layer may contain additives insofar as they achieve the effects of the present invention. Examples of such additives include colorants, antioxidants, flame retardants, ultraviolet absorbers, antibacterial agents, antistatic agents, deodorizers, and termite repellents.

[0060] The content ratio of additives in the moisture-permeable resin layer is preferably 0% by mass or more and 10% by mass or less for each additive, as expressed as a mass ratio to the moisture-permeable resin layer.

[0061] (Method for manufacturing a moisture-permeable resin layer) The moisture-permeable resin layer can be obtained by appropriately mixing the above-mentioned resins and additives and forming a film using various molding methods.

[0062] One method for mixing resins and additives is dry blending. Examples of dry blending methods include using a V-type blender, tumbler, Henschel mixer, and high-speed rotary mixer. Alternatively, melt kneading using an extruder may be used as a mixing method. Examples of extruders include single-screw extruders and twin-screw extruders. In addition, a masterbatch containing the resins may be prepared in advance and used for mixing.

[0063] Examples of film forming methods include inflation molding (air cooling, water cooling, multi-stage cooling, and high-speed processing) and T-die film forming. Among these, inflation molding is preferred. When a moisture-permeable resin layer is produced by inflation molding, it is possible to form the film at a lower temperature compared to other molding methods, so thermal degradation of the resin is less likely to occur, and a film with superior cleanliness and mechanical strength tends to be obtained.

[0064] [Method for manufacturing a moisture-permeable airtight sheet] The moisture-permeable airtight sheet of this embodiment includes a base layer made of nonwoven fabric, a breathable olefin-based hot-melt adhesive layer, and a moisture-permeable resin layer. In this embodiment, it is important to laminate and integrate the base layer and the moisture-permeable resin layer so that the olefin-based hot-melt adhesive layer is breathable without impairing the moisture resistance characteristics. One such lamination method is to first partially coat or spray-coat a heated and melted olefin-based hot-melt adhesive onto the bonding surface of the base layer (on at least one side of the base layer) to form an olefin-based hot-melt adhesive layer on the base layer, and then bond the moisture-permeable resin layer onto the adhesive layer to integrate them.

[0065] As a method of partial coating, instead of applying the heated and melted olefin-based hot melt adhesive to the entire bonding surface of the substrate layers (at least one side of the substrate layers) using a known spatula or the like, one method is to apply it partially in a web-like manner.

[0066] One method of spray coating is to use a spray coating machine to spray-coat the entire surface of the bonding surface (at least one side of the substrate layer) of the substrate layers with a heat-melted olefin-based hot-melt adhesive, rather than spray-coating it partially in a web-like manner.

[0067] When forming an adhesive layer on a substrate layer, it is preferable to impregnate the nonwoven fabric with an olefin-based hot melt adhesive. One example of an impregnation method is to immerse the nonwoven fabric in an olefin-based hot melt adhesive. By forming an adhesive layer in this way and then bonding a moisture-permeable resin layer onto that adhesive layer, the lamination strength between the substrate layer and the moisture-permeable resin layer tends to be higher.

[0068] One method for bonding the base material layer and the moisture-permeable resin layer is, for example, a method of bonding by roll pressing. Such roll pressing methods include, for example, a method in which the base material layer, adhesive layer, and moisture-permeable resin layer are sandwiched between known embossed rolls and smooth rolls and roll-pressed, and a method in which smooth rolls are used instead of embossed rolls for roll pressing. Among these, roll pressing using embossed rolls and smooth rolls is preferable because it has non-pressed areas (non-embossed areas), making it easier to adjust humidity permeability, and because a strong bond is formed in the pressed areas (embossed areas), a moisture-permeable airtight sheet with sufficient mechanical strength tends to be obtained.

[0069] Shapes that can be obtained using the embossing roll include, for example, circular, rhomboid, square, and elliptical shapes. It is preferable to evenly distribute these shapes in the moisture-permeable resin layer. The area of ​​each projection or indentation of the embossing roll is preferably 10 mm². 2 The following, and more preferably 0.2 mm 2 6mm or more 2 The following applies:

[0070] The pressure during roll crimping is preferably 10 N / cm to 1000 N / cm, and more preferably 20 N / cm to 700 N / cm.

[0071] [Physical properties of moisture-permeable airtight sheets] The moisture-permeable airtight sheet of this embodiment preferably has the following moisture permeability (moisture resistance value). Because a breathable adhesive layer is interposed between the base material layer and the moisture-permeable resin layer, the moisture-permeable airtight sheet has suitable moisture permeability, making it possible to suitably create a humidity gradient between indoors and outdoors, for example. For specific methods of measuring each moisture resistance value, please refer to the examples.

[0072] The low-humidity water vapor permeability resistance value, measured in accordance with ISO 12572:2016 and numerically converted from the water vapor permeability resistance calculation method of JIS-A-1324, under conditions of 23°C and 25%RH (23°C and 0%RH inside the vapor permeability cup, 23°C and 50%RH outside), is 82m 2·s·Pa / μg or more 500m 2 The value is less than or equal to s·Pa / μg, preferably 130m 2 ·s·Pa / μg or more 490m 2 It is less than or equal to s·Pa / μg.

[0073] The moisture permeability resistance value at medium humidity under conditions of 23°C and 62.5%RH (23°C and 75%RH inside the moisture permeability cup, 23°C and 50%RH outside environment), measured in accordance with ISO12572:2016 and numerically converted from the moisture permeability resistance calculation method of JIS-A-1324, is 30m 2 ·s·Pa / μg or more 70m 2 ·s·Pa / μg or less, preferably 35m 2 ·s·Pa / μg or more 50m 2 It is less than or equal to s·Pa / μg.

[0074] The high-humidity water vapor permeability resistance value, measured in accordance with ISO 12572:2016 and numerically converted from the water vapor permeability resistance calculation method of JIS-A-1324, under conditions of 23°C and 90%RH (23°C and 100%RH inside the water vapor permeability cup, 23°C and 80%RH outside), is 1m 2 ·s·Pa / μg or more 20m 2 ·s·Pa / μg or less, preferably 1m 2 ·s·Pa / μg or more 15m 2 It is less than or equal to s·Pa / μg.

[0075] Moisture-permeable airtight sheets tend to exhibit high moisture permeability at low humidity levels and low moisture permeability at high humidity levels.

[0076] When the moisture vapor resistance value at low humidity falls within the above range, a more favorable humidity gradient from indoors to outdoors tends to be formed when a moisture-permeable airtight sheet is used as a vapor barrier in a wall structure. Furthermore, when the moisture vapor resistance value at medium humidity and high humidity falls within the above range, it tends to become easier to control the water vapor pressure so that the humidity gradually reaches equilibrium. When the moisture vapor resistance value at medium humidity falls within the above range, it becomes easier to expel moisture from inside the wall structure to the outdoors during hot and humid summers, and condensation inside the wall structure tends to be less likely to occur.

[0077] The basis weight of the moisture-permeable airtight sheet is preferably 60 g / m². 2 More than 150g / m 2 The following is more preferable: 70 g / m² 2 More than 110g / m 2 The following is more preferably 75 g / m² 2 More than 100g / m 2 The following applies: The weight is 60g / m². 2 At this level, the mechanical strength of the moisture-permeable airtight sheet improves, and it tends to become less prone to tearing. 2 The following conditions tend to result in a breathable, airtight sheet with excellent flexibility and workability.

[0078] The moisture-permeable airtight sheet of this embodiment preferably has a staple-holding strength of 15N or more, more preferably 20N or more, and even more preferably 30N or more, as measured in accordance with JIS-A-6930. The upper limit of the staple-holding strength is not particularly limited, but for example, it is 60N or less. When the staple-holding strength is within the above range, the sheet is less likely to tear from the staples of the tacker during house construction, and a more suitable moisture-permeable airtight sheet tends to be obtained. For specific methods of measuring the staple-holding strength, please refer to the examples.

[0079] The vapor-permeable airtight sheet of this embodiment has an air permeability resistance of 900 seconds or more, more preferably 1000 seconds or more, as measured in accordance with the JIS-P-8117 Gurley tester method B. The upper limit of the air permeability resistance is the measurement limit of the JIS-P-8117 Gurley tester method B, which is 1300 seconds or less. When the air permeability resistance is within the above range, gas tends to have difficulty permeating into the vapor-permeable airtight sheet. Therefore, for example, by installing a vapor-permeable airtight sheet in a building such as a house, the building will have good and excellent airtightness, and it will be possible to suitably reduce the energy spent on heating and cooling inside the building. For specific methods of measuring air permeability resistance, please refer to the examples.

[0080] The moisture-permeable airtight sheet preferably has a total light transmittance of 40% to 75%, as measured in accordance with JIS-K-7361-1. A total light transmittance of 40% or more tends to facilitate construction by allowing sufficient confirmation of the substrate inside the wall structure during installation. A total light transmittance of 75% or less tends to achieve sufficient moisture resistance and strength as a moisture-permeable airtight sheet.

[0081] The moisture-permeable airtight sheet of this embodiment can reduce the water vapor pressure so that humidity gradually moves from the high-humidity side to the low-humidity side between the inside and outside, where the temperature and humidity are different, and the humidity levels become equilibrium. Therefore, the moisture-permeable airtight sheet can be suitably used in wall structures, but is not limited to wall structures and can also be used in structures that require such a function, such as roof structures. [Examples]

[0082] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way by these examples.

[0083] [Measurement method] (1) Basis weight of nonwoven fabrics and moisture-permeable airtight sheets The nonwoven fabric obtained in Comparative Example 1, the moisture-permeable airtight sheets obtained in Examples 1-4, and the respective sheets obtained in Comparative Examples 1 and 2 were cut into 100 mm squares, and the mass (g) of the cut samples was measured. This value was then measured per 1 m 2 By converting to mass per unit area, the basis weight (g / m²) of the moisture-permeable airtight sheet can be calculated. 2 ) was obtained.

[0084] (2) Lamination strength The laminate strength (N / 50mm) between the base material layer and the moisture-permeable resin layer was measured using the Tensilon RTG-1210 universal material tester (product name, manufactured by A&D). Specifically, the edges of each moisture-permeable airtight sheet obtained in Examples 1-4 and Comparative Examples 1 and 2 were immersed in an organic solvent, the edges were peeled off, and the sheets were air-dried. Then, a peel test was performed between the base material layer and the moisture-permeable resin layer using the Tensilon universal material tester, and the laminate strength between these layers was measured and evaluated according to the following criteria. Digital photographs after the peel test for each moisture-permeable airtight sheet obtained in Example 2 and Comparative Example 1 are shown in Figures 1 and 2. As shown in Figures 1 and 2, the moisture-permeable airtight sheet obtained in Example 2 differed from the moisture-permeable airtight sheet obtained in Comparative Example 1 in that it had an olefin-based hot-melt adhesive layer, resulting in higher laminate strength. (standard) ○: The laminate strength was 2N / 50mm or higher. ×: The lamination strength was less than 2N / 50mm.

[0085] (3) Delamination state due to temperature cycle The delamination state due to temperature cycling was measured as follows. First, the moisture-permeable airtight sheets obtained in Examples 1-4 and Comparative Examples 1 and 2 were placed in a constant temperature and humidity chamber (IX-110, manufactured by Yamato Scientific Co., Ltd.) at 60°C and held for 1 hour. After that, they were left in a 23°C atmosphere for 1 hour, and this cycle was considered one cycle. This cycle was repeated 30 times. The appearance of each moisture-permeable airtight sheet after 30 cycles was visually inspected and evaluated according to the following criteria. (standard) ○: After 30 cycles, no delamination was observed between the moisture-permeable resin layer and the substrate layer. ×: After 30 cycles, delamination was observed between the moisture-permeable resin layer and the substrate layer.

[0086] (4) Water vapor resistance value Using a constant temperature and humidity chamber (IX-110 (model), manufactured by Yamato Scientific Co., Ltd.), the water vapor resistance values ​​(m) of the respective moisture-permeable airtight sheets obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were measured. 2 The resistance values ​​were measured (·s·Pa / μg) and evaluated. Specifically, the measurements were performed as follows:

[0087] • Water vapor permeability resistance value at low humidity The constant temperature and humidity chamber was set to an external environment of 23°C and 50%RH. A moisture-permeable cup containing a desiccant was placed inside the chamber, and the temperature inside the cup was set to 23°C and 0%RH. The moisture-permeable airtight sheets obtained in Examples 1-4 and Comparative Examples 1 and 2 were placed inside the moisture-permeable cup, and the amount of moisture permeation was measured under the conditions of 23°C and 25%RH in accordance with ISO 12572:2016. The obtained amount of moisture permeation was used to calculate the moisture resistance value at low humidity (m³) by numerical conversion using the moisture resistance calculation method of JIS-A-1324. 2 The water vapor permeability resistance (·s·Pa / μg) was calculated, and the low-humidity water vapor permeability resistance was evaluated according to the following criteria. (standard) 〇: 130m 2 ·s·Pa / μg or more 500m 2 ·s·Pa / μg or less △: 82m 2 ·s·Pa / μg or more 130m 2 Less than s·Pa / μg ×: 82m 2 Less than s·Pa / μg

[0088] • Moisture permeability resistance value at moderate humidity The constant temperature and humidity chamber was set to an external environment of 23°C and 50%RH. A moisture-permeable cup containing a saturated sodium chloride solution was placed inside the chamber, and the temperature inside the cup was set to 23°C and 75%RH. The moisture-permeable airtight sheets obtained in Examples 1-4 and Comparative Examples 1 and 2 were placed inside the moisture-permeable cup, and the amount of moisture permeation was measured under the conditions of 23°C and 62.5%RH at medium humidity in accordance with ISO 12572:2016. The obtained amount of moisture permeation was used to numerically convert the moisture permeation resistance value at medium humidity (m) using the moisture permeation resistance calculation method of JIS-A-1324. 2The water vapor permeability resistance (·s·Pa / μg) was calculated, and the water vapor permeability resistance value at moderate humidity was evaluated according to the following criteria. (standard) 〇:30m 2 ·s·Pa / μg or more 50m 2 ·s·Pa / μg or less △: 50m 2 • exceeding 70 m² (s·Pa / μg) 2 ·s·Pa / μg or less ×: 70m 2 Exceeding s·Pa / μg

[0089] • Water vapor permeability resistance value at high humidity First, the constant temperature and humidity chamber was set to an external environment of 23°C and 80%RH. A water-filled moisture-permeable cup was placed inside the chamber, and the inside of the cup was set to 23°C and 100%RH. The moisture-permeable airtight sheets obtained in Examples 1-4 and Comparative Examples 1 and 2 were placed inside the moisture-permeable cup, and the amount of moisture permeation under the conditions of 23°C and 90%RH was measured in accordance with ISO 12572:2016. Using the obtained amount of moisture permeation, the high-humidity moisture permeation resistance value (m) was calculated by numerical conversion using the moisture permeability resistance calculation method of JIS-A-1324. 2 The water vapor permeability resistance (·s·Pa / μg) was calculated, and the high-humidity water vapor permeability resistance was evaluated according to the following criteria. (standard) 〇:1m 2 ·s·Pa / μg or more 15m 2 ·s·Pa / μg or less △: 15m 2 • s·Pa / μg exceeding 20m 2 ·s·Pa / μg or less ×: 20m 2 Exceeding s·Pa / μg

[0090] (5) Staple retention strength In accordance with JIS-A-6930, the staple retention strength (N) of each moisture-permeable airtight sheet obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was measured, and the staple retention strength was evaluated according to the following criteria. (standard) 〇: 30N or more and 60N or less △: 15N or more and less than 30N ×: Less than 15N

[0091] (6) Air permeability resistance The air permeability resistance values ​​(seconds) of each moisture-permeable airtight sheet obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were measured in accordance with the JIS-P-8117 Gurley Testing Machine Type B.

[0092] [Example 1] Ethylene-vinyl alcohol copolymer resin (Soanol®, manufactured by Mitsubishi Chemical Corporation; ethylene content: 33 mol%, vinyl alcohol content: 67 mol%, MFR (temperature 210°C and load 2.16 kg): 4.0 g / 10 min, melting point: 170°C, glass transition temperature: 58°C) 90 parts by mass and ethylene-vinyl acetate copolymer saponified resin (Mersen® H, manufactured by Tosoh Corporation; degree of saponification: 75 mol%, density: 960 kg / m³) 3 10 parts by mass of a material with a melting point of 109°C and MFR (temperature 190°C and load 2.16 kg): 2.8 g / 10 min was mixed by dry blending, and a film was obtained using an inflation molding machine (manufactured by Hokushin Sangyo Co., Ltd.).

[0093] Furthermore, the base layer is a spunbond nonwoven fabric (basis weight 30g / m²) which is a composite fiber having a core-sheath structure in which the core is polyethylene terephthalate and the sheath is polyethylene. 2 The Elves® series manufactured by Unitika Ltd. was used.

[0094] Then, a heated and melted olefin-based hot melt adhesive (modified olefin-based, Evergrip® AS896 (product name) manufactured by Toagosei Co., Ltd.) was partially spray-coated onto the nonwoven fabric (base layer) in a web-like pattern, impregnating the nonwoven fabric with the adhesive to form an olefin-based hot melt adhesive layer on the nonwoven fabric. Subsequently, a film obtained as a moisture-permeable resin layer was laminated onto this adhesive layer, and a moisture-permeable airtight sheet was obtained by roll-pressing the adhesive layer and the moisture-permeable resin layer using an embossing roll and a smooth roll.

[0095] [Example 2] The base layer is a spunbond nonwoven fabric (basis weight 40g / m²) which is a composite fiber having a core-sheath structure in which the core is polyethylene terephthalate and the sheath is polyethylene. 2 A moisture-permeable airtight sheet was obtained in the same manner as in Example 1, except that Unitika Ltd.'s Elves® series was used.

[0096] [Example 3] The base layer is a spunbond nonwoven fabric (basis weight 90g / m²) which is a composite fiber having a core-sheath structure in which the core is polyethylene terephthalate and the sheath is polyethylene. 2 A moisture-permeable airtight sheet was obtained in the same manner as in Example 1, except that Unitika Ltd.'s Elves® series was used.

[0097] [Example 4] In Example 4, 75 parts by mass of ethylene-vinyl alcohol copolymer resin (Soanol®, manufactured by Mitsubishi Chemical Corporation; ethylene content: 33 mol%, vinyl alcohol content: 67 mol%, MFR (temperature 210°C and load 2.16 kg): 4.0 g / 10 min, melting point: 170°C, glass transition temperature: 58°C) and ethylene-vinyl acetate copolymer saponified resin (Mersen® H, manufactured by Tosoh Corporation; degree of saponification: 75 mol%, density: 960 kg / m³) were used. 3 10 parts by mass of a material with a melting point of 109°C and MFR (temperature 190°C and load 2.16 kg): 2.8 g / 10 min, and 15 parts by mass of an ethylene-vinyl acetate copolymer resin (Suntech®-EVA, manufactured by Asahi Kasei Corporation, ethylene content: 91% by mass, vinyl acetate content: 9% by mass) were mixed by dry blending, and a film was obtained using an inflation molding machine (manufactured by Hokushin Sangyo Co., Ltd.). A moisture-permeable airtight sheet was obtained in the same manner as in Example 2, except that the obtained film was used as the moisture-permeable resin layer.

[0098] [Comparative Example 1] Ethylene-vinyl alcohol copolymer resin (Soanol®, manufactured by Mitsubishi Chemical Corporation; ethylene content: 33 mol%, vinyl alcohol content: 67 mol%, MFR (temperature 210°C and load 2.16 kg): 4.0 g / 10 min, melting point: 170°C, glass transition temperature: 58°C) 80 parts by mass and butenediol-vinyl alcohol copolymer resin (Nichigo G Polymer®, manufactured by Mitsubishi Chemical Corporation) 20 parts by mass were mixed by dry blending, and a film was obtained using an inflation molding machine (manufactured by Hokushin Sangyo Co., Ltd.).

[0099] Furthermore, the base layer is made of polypropylene spunbond thermoplastic long fiber nonwoven fabric (basis weight 45g / m²). 2 This nonwoven fabric was obtained by partially heat-pressing a long-fiber polypropylene web, which was heated, melted, and extruded in an extruder, using an embossing roll and a smoothing roll.

[0100] Then, using an extrusion laminating apparatus, a moisture-permeable airtight sheet was obtained by directly laminating the base layer of the obtained polypropylene spunbond thermoplastic long-fiber nonwoven fabric with the moisture-permeable resin layer of the obtained film.

[0101] [Comparative Example 2] In Example 2, a heated and melted olefin-based hot-melt adhesive (modified olefin-based, Evergrip® AS896 (product name) manufactured by Toagosei Co., Ltd.) was spray-coated onto the nonwoven fabric (base layer) to impregnate the nonwoven fabric with the adhesive, thereby forming an olefin-based hot-melt adhesive layer over the entire surface of the nonwoven fabric. Subsequently, the film obtained in Example 1 was laminated on the adhesive layer as a moisture-permeable resin layer, and a moisture-permeable airtight sheet was obtained by roll-pressing the adhesive layer and the moisture-permeable resin layer using an embossing roll and a smoothing roll.

[0102] The moisture-permeable airtight sheets obtained in Examples 1-4 and Comparative Examples 1 and 2 were subjected to the various evaluations described above. The results are shown in Table 1.

[0103] [Table 1]

[0104] The abbreviations listed in Table 1 are as follows: PET: Polyethylene terephthalate PE: Polyethylene PP: Polypropylene EVOH: Ethylene-vinyl alcohol copolymer resin EVAC: Ethylene-vinyl acetate copolymer saponified resin EVA: Ethylene-vinyl acetate copolymer resin BVA: Butenediol-vinyl alcohol copolymer resin

[0105] (Actual usage evaluation) In Example 2, the moisture-permeable airtight sheet was used as a vapor barrier, and a wall structure was formed by combining interior material, vapor barrier, 100 mm thick glass wool insulation, a ventilation layer approximately 25 mm wide, windproof paper, and exterior material in that order. Here, the vapor barrier (moisture-permeable airtight sheet) was positioned with the side facing the moisture-permeable resin layer facing the glass wool insulation.

[0106] The resulting wall structure was used in wooden houses, and the occurrence of summer and winter condensation was observed in Kyushu and the Chugoku region. As a result, it was confirmed that neither type of condensation occurred at all. [Explanation of symbols]

[0107] 1…Moisture-permeable resin layer, 2…Olefin-based hot-melt adhesive layer, 3…Base layer (nonwoven fabric)

Claims

1. Weight: 20 g / m 2 More than 100g / m 2 A base layer consisting of the following nonwoven fabrics, The substrate layer includes a moisture-permeable resin layer on at least one side, A moisture-permeable airtight sheet comprising a breathable olefin-based hot-melt adhesive layer between the base material layer and the moisture-permeable resin layer, A moisture-permeable airtight sheet in which the moisture-permeable resin layer contains an ethylene-vinyl alcohol copolymer resin.

2. The low-humidity water vapor permeability resistance value, measured in accordance with ISO 12572:2016 and numerically converted from the water vapor permeability resistance calculation method of JIS-A-1324, under conditions of 23°C and 25% RH (23°C and 0% RH inside the vapor permeability cup, 23°C and 50% RH outside environment), was 82 m³. 2 ・s・Pa / μg or more 500m 2 • s・Pa / μg or less, The moisture permeability resistance value at medium humidity under conditions of 23°C and 62.5% RH (23°C and 75% RH inside the moisture permeability cup, 23°C and 50% RH outside the environment), measured in accordance with ISO 12572:2016 and numerically converted from the moisture permeability resistance calculation method of JIS-A-1324, is 30 m 2 ・s・Pa / μg or more 70m 2 • s・Pa / μg or less, The high-humidity water vapor permeability resistance value measured in accordance with ISO 12572:2016 and numerically converted from the water vapor permeability resistance calculation method of JIS-A-1324 is 1 m³ under conditions of 23°C and 90% RH (23°C and 100% RH inside the water vapor permeability cup, 23°C and 80% RH outside). 2 ・s・Pa / μg or more 20m 2 • It is less than or equal to s・Pa / μg. The moisture-permeable airtight sheet according to claim 1.

Images