Breathable waterproof sheet for building materials

Abstract

To provide an economical moisture permeable waterproof sheet excellent in moisture permeability capable of suppressing degradation even when being exposed to solar light for an extended period and having high waterproof performance over a long period after being installed inside of an outer wall as well as securing natural light even when interior construction before exterior construction.SOLUTION: Moisture permeable waterproof sheet for building material is configured to laminate a nonwoven fabric layer, an air permeable adhesive resin layer, and a permeable waterproof film layer, wherein total thickness of vapor permeable waterproof films used for the vapor permeable waterproof film layer is 50 to 100 μm, and ultraviolet average transmittance from 280 to 400 nm of the vapor permeable waterproof film layer is equal to or less than 2%. A moisture permeation resistance value measured in accordance with JIS A6111 for moisture permeable waterproof sheet for building material is equal to or less than 0.19 m2 s Pa / μg, visible light average transmittance of 400 to 700 nm is equal to or more than 8%, and ultraviolet average transmittance of 280 to 400 nm is equal to or less than 2%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a breathable waterproof sheet for building materials used as a base material for the exterior walls of houses. [Background technology]

[0002] Conventionally, methods have been developed to release moisture from within the wall structure to the outside, such as the exterior wall ventilation method. In the exterior wall ventilation method, a breathable waterproof sheet is generally installed on the exterior side of the insulation material to efficiently release moisture. Since these breathable waterproof sheets are installed on the inside of the exterior wall material, long-term durability is required, such as durability in tensile strength and water pressure resistance.

[0003] The applicant has proposed, for example, Patent Documents 1 and 2, as a breathable waterproof sheet with excellent moisture permeability, waterproofing, and heat shielding properties, and long-term durability that can withstand harsh environments such as high temperature and high humidity. While these have excellent moisture permeability, waterproofing, and heat shielding properties, they are not designed to withstand long-term exposure to sunlight before installation, and further durability is required. For example, the JIS durability evaluation assumes 44 MJ / m² of sunlight exposure for two months. 2 Although the plan is to conduct durability acceleration evaluation tests by heat treatment after irradiation with ultraviolet light, in actual construction, the exterior wall material may be left unattended for far more than two months. Long-term exposure to ultraviolet light accelerates oxidative degradation that occurs within the exterior wall after construction, reducing long-term durability, so it is necessary to suppress degradation caused by ultraviolet light. Furthermore, if a metal vapor-deposited film or black film that reflects ultraviolet light is used on the surface to suppress degradation and obtain the durability of waterproofing performance, the cost increases and the visible light transmittance decreases significantly, resulting in insufficient brightness inside the building after construction, and problems such as difficulty in carrying out interior work before the exterior wall is installed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-076210 [Patent Document 2] Republished Patent No. 2015 / 151460 [Overview of the project] [Problems that the invention aims to solve]

[0005] This invention has been made in view of the above problems, and aims to provide an inexpensive breathable waterproof sheet that has excellent breathability and waterproofing properties, suppresses deterioration even when exposed to sunlight for a long period of time, maintains high waterproofing performance for a long period of time even after being installed inside the exterior wall, and ensures brightness even during interior construction before the installation of the exterior wall material. [Means for solving the problem]

[0006] The present invention relates to a breathable waterproof sheet for building materials, comprising a nonwoven fabric layer, a breathable adhesive resin layer, and a breathable waterproof film layer, wherein the total thickness of the breathable waterproof film used in the breathable waterproof film layer is 50 to 100 μm, and the average ultraviolet transmittance of the breathable waterproof film layer at 280 to 400 nm is 2% or less, and the moisture resistance value measured in accordance with JIS A6111 for the breathable waterproof sheet for building materials is 0.19 m 2 This is a breathable waterproof sheet for building materials that has a viscosity of s·Pa / μg or less, an average visible light transmittance of 8% or more in the 400-700nm range, and an average ultraviolet light transmittance of 2% or less in the 280-400nm range.

[0007] Furthermore, it is preferable that the moisture-permeable waterproof film layer is formed by two layers of moisture-permeable waterproof film with a breathable adhesive resin layer in between. [Effects of the Invention]

[0008] The present invention can provide an inexpensive moisture-permeable waterproof sheet that has excellent moisture permeability and waterproof properties, suppresses deterioration even when exposed to sunlight for a long time, has high waterproof performance over a long period even after being installed inside an outer wall, and can ensure indoor brightness during interior decoration before installing the outer wall.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 8 is a schematic cross-sectional view showing a moisture-permeable waterproof sheet for building materials, which is an example of an embodiment of the present invention. [Figure 2] FIG. 11 is a schematic cross-sectional view showing a moisture-permeable waterproof sheet for building materials, which is another example of an embodiment of the present invention.

Modes for Carrying Out the Invention

[0010] Hereinafter, the moisture-permeable waterproof sheet for building materials of the present invention will be described with reference to the drawings. In the drawings, although a plurality of layers constituting the moisture-permeable waterproof sheet for building materials of the present invention are shown, the thickness and size of each layer have been appropriately changed for ease of explanation and do not accurately reflect the magnitude relationship of the thickness of each layer in the actual moisture-permeable waterproof sheet for building materials.

[0011] As shown in FIG. 1, the moisture-permeable waterproof sheet 1 for building materials of the present invention has a non-woven fabric layer 2, a breathable adhesive resin layer 3, and a moisture-permeable waterproof film layer 4 laminated in this order. Further, as shown in FIG. 2, the moisture-permeable waterproof film layer 4 includes those laminated like a moisture-permeable waterproof film 41 and a moisture-permeable waterproof film 42, and the moisture-permeable waterproof film layer 4 may be laminated with a plurality of moisture-permeable waterproof films.

[0012] The moisture-permeable waterproof sheet 1 for building materials is usually installed inside an outer wall material. The non-woven fabric layer 2 side of the moisture-permeable waterproof sheet 1 is installed on the outdoor side surface of the heat insulating material, and the moisture-permeable waterproof film layer 4 side of the moisture-permeable waterproof sheet 1 is installed on the indoor side surface of the outer wall material.

[0013] As the moisture-permeable and waterproof film layer 4 used in the present invention, a porous moisture-permeable and waterproof film capable of obtaining moisture permeability and waterproofness can be used. Examples of the material include polyolefin resins such as polyethylene and polypropylene, and polyethylene-based resins are preferable in terms of processability.

[0014] The moisture-permeable and waterproof film may be a moisture-permeable and waterproof film having fine pores. As the manufacturing method, there are a method of stretching a resin composition obtained by melt-kneading inorganic particles such as calcium carbonate and titanium oxide into a polyolefin resin, a thermoplastic resin, a crystal nucleating agent, and a compounding agent that is miscible with the thermoplastic resin and dissolves at the melting temperature of the thermoplastic resin but causes phase separation when cooled to a temperature below the crystallization temperature of the thermoplastic resin. A method of stretching the composition, or a method of physically forming fine pores by a needle or an embossing roll. Among them, a method of stretching a resin composition obtained by melt-kneading inorganic particles is preferable in terms of moisture permeability.

[0015] In the method of stretching a resin composition obtained by melt-kneading inorganic particles such as calcium carbonate and titanium oxide into a polyolefin resin, the average particle diameter of the inorganic particles is preferably 10 μm or less on a volume basis, more preferably 0.5 to 5 μm, and even more preferably 0.7 to 3 μm. When the average particle diameter is within the above range, the dispersibility is excellent, the continuous formation of pores during stretching becomes easy, and breakage during film stretching molding is less likely to occur. The weight ratio of the inorganic particles to be contained is preferably in the range of 40 to 60% by weight, more preferably in the range of 45 to 50% by weight, based on the total weight after mixing with the polyolefin resin. If it is more than 60% by weight, there is a risk of poor film formability, reduction of mechanical strength, breakage during stretching, etc. Also, if it is less than 45% by weight, the moisture permeability of the moisture-permeable and waterproof film after stretching may be insufficient. It is preferable that the moisture-permeable and waterproof film contains inorganic particles to such an extent that it becomes white.

[0016] Additives can be added to the breathable waterproof film. Examples include antioxidants (hindered phenol, thioether, phosphite, etc.) and light stabilizers (benzophenone-based UV absorbers, benzotriazole-based UV absorbers, hindered amine-based light stabilizers, etc.). These additives may be used individually or in combination of multiple types.

[0017] The moisture permeability resistance value of the breathable waterproof film layer 4, measured in accordance with JIS A6111, is 0.19 m 2 The value is less than or equal to s·Pa / μg, preferably 0.13m 2 ·s·Pa / μg or less, more preferably 0.10m 2 The water vapor permeability resistance is less than or equal to s·Pa / μg. 2 If the value is greater than s·Pa / μg, the required moisture permeability cannot be ensured in the moisture-permeable waterproof sheet 1 for building materials. The lower limit of the moisture resistance value is 0.03 m from the standpoint of waterproofing. 2 It is preferable that the value is s·Pa / μg or higher.

[0018] Furthermore, the average UV transmittance of the breathable waterproof film layer 4 in the 280-400 nm range is 2% or less, preferably 1.5% or less. If the average UV transmittance is greater than 2%, UV degradation will progress throughout the entire thickness direction of the breathable waterproof film layer 4 during outdoor exposure. If the exterior wall material is installed after more than four months of outdoor exposure, oxidative degradation occurring within the exterior wall over time will be accelerated, making it difficult to maintain long-term waterproofing.

[0019] Furthermore, it is preferable that the average visible light transmittance of the breathable waterproof film layer 4 in the 400-700 nm range be 10% or more. If the average visible light transmittance is less than 10%, when other layers are laminated to form a breathable waterproof sheet 1 for building materials, sufficient brightness may not be ensured indoors after construction, which may reduce work efficiency in the construction process after construction.

[0020] The waterproofness of the breathable waterproof film layer 4 is preferably 5 to 120 kPa, and more preferably 6 to 100 kPa, in measurements in accordance with the waterproofness evaluation (Method B (high water pressure method)) of JIS A6111. If it is less than 5 kPa, the waterproofness may be insufficient, and if it is greater than 120 kPa, the conflicting breathability may be greatly impaired.

[0021] Furthermore, the total thickness of the breathable waterproof film used in the breathable waterproof film layer 4 is preferably 50 to 100 μm, and more preferably 60 to 90 μm. If it is less than 50 μm, sufficient UV resistance may not be obtained. By keeping the average UV transmittance of the breathable waterproof film layer 4 to 2% or less and having a total thickness of 50 μm or more, UV degradation damage can be limited to the surface layer of the film, and the overall strength of the film can be maintained. This suppresses the acceleration of oxidative degradation that occurs during long-term exposure inside the wall after the exterior wall material has been installed, and maintains excellent waterproofing. Also, if the total thickness is thicker than 100 μm, the visible light transmittance will worsen, which may impair indoor workability after installation and reduce flexibility, thus impairing workability. In addition, if a method of stretching a resin composition obtained by melting and kneading inorganic particles is selected as the preferred manufacturing method for the breathable waterproof film, if the film is too thick, stretching becomes difficult, making it impossible to form uniform pores, and the required breathability may not be obtained.

[0022] Furthermore, the tensile strength of the breathable waterproof film layer 4 is preferably 10 N / 25 mm or more in the vertical direction and 3 N / 25 mm or more in the horizontal direction. If it is lower than this, problems such as film tearing may occur during lamination. In this invention, the vertical direction and horizontal direction refer to the length direction and width direction, respectively, when the film is made.

[0023] The tensile elongation at break of the breathable waterproof film layer 4 is preferably 10% or more in both the longitudinal and transverse directions. If it is less than 10%, the processability during lamination may be poor.

[0024] The moisture-permeable and waterproof film layer 4 may be composed of a moisture-permeable and waterproof film, and it may be a single layer or multiple layers. However, since the manufacturing cost increases as the number of laminated layers increases, it is preferably 1 layer or 2 layers. As shown in FIG. 2, when two layers of a moisture-permeable and waterproof film 41 and a moisture-permeable and waterproof film 42 are laminated via a breathable adhesive resin layer 5, the damage due to deterioration by ultraviolet rays is limited to only the moisture-permeable and waterproof film 42 which becomes the surface layer, and the damage due to deterioration by ultraviolet rays stops at only the more surface layer portion, which is preferable. The breathable adhesive resin layer 5 will be described later.

[0025] The material of the non-woven fabric layer 2 is preferably composed of a non-woven fabric made of polyester-based or polyolefin-based filament fibers in terms of strength, light weight, and price. In particular, polyester-based fibers are preferably used in terms of strength and durability. Also, examples of the type of manufacturing method include spunbond, meltblown chemical bond, thermal bond, spunlace, needle punch, etc. In particular, the manufacturing methods of spunbond and meltblown are preferable in terms of strength and post-processing properties.

[0026] Also, the basis weight of the non-woven fabric layer 2 is preferably 30~150 g / m 2 and more preferably 45~100 g / m 2 . If the basis weight of the non-woven fabric layer 2 is less than 30 g / m 2 , there is a risk that sufficient strength cannot be obtained for the moisture-permeable and waterproof sheet 1 for building materials. Also, if the basis weight is greater than 150 g / m 2 , when used as the moisture-permeable and waterproof sheet 1 for building materials, flexibility may not be obtained and the workability may be significantly reduced.

[0027] In the moisture-permeable and waterproof sheet 1 for building materials of the present invention, a breathable adhesive resin layer 3 is provided between the non-woven fabric layer 2 and the moisture-permeable and waterproof film layer 4, and a breathable adhesive resin layer 5 is provided between the moisture-permeable and waterproof film layer 41 and the moisture-permeable and waterproof film layer 42, and they are integrally laminated.

[0028] The adhesive resins used in the breathable adhesive resin layer 3 and the breathable adhesive resin layer 5 only need to be applied in a way that allows for breathability after lamination, and specific examples include shapes such as dots or spiderwebs. Application methods include spraying, dispensing, or gravure printing.

[0029] The type of adhesive resin is appropriately selected depending on the material of the nonwoven fabric layer 2 and the breathable waterproof film layer 4, but examples include hot-melt adhesives such as polyethylene resin and other olefin resins, ethylene-vinyl acetate copolymer resins, polyurethane resins, and polyamide resins. Ethylene-vinyl acetate copolymer resins are preferred in terms of adhesive strength and cost. In addition, known antioxidants, ultraviolet absorbers, flame retardants, coloring pigments, etc. can be added to the adhesive resin as additives.

[0030] Furthermore, the thickness of the breathable adhesive resin layer 3 and the breathable adhesive resin layer 5 is preferably 30 μm or less, and more preferably 15 μm or less, from the viewpoint of flexibility and workability.

[0031] In this invention, a nonwoven fabric can be further laminated to the outer surface of the breathable waterproof film layer 4, i.e., the surface facing the exterior wall material, via a breathable adhesive resin layer. By laminating the nonwoven fabric, waterproofing, strength, and durability can be improved, and it is also preferable in terms of scratch resistance to the breathable waterproof film layer 4. The nonwoven fabric used here is preferably composed of polyester or polyolefin filament fibers, similar to the material of the nonwoven fabric layer 2, in terms of strength, lightness, and cost. Furthermore, it is not particularly limited as long as it does not hinder the concept of this invention. From the standpoint of handling the breathable waterproof sheet for building materials, the basis weight is 40 g / m². 2 Preferably, it is 30 g / m 2 The following is more preferable, as it also maintains strength: 20g / m 2 It is preferable if the above conditions are met.

[0032] The moisture-permeable waterproof sheet 1 for building materials has a moisture resistance value of 0.19 m³ measured in accordance with JIS A6111. 2The concentration is less than or equal to s·Pa / μg. Preferably 0.13m 2 ·s·Pa / μg or less, more preferably 0.10m 2 The water vapor permeability resistance is less than or equal to s·Pa / μg. 2 If the value is greater than s·Pa / μg, it is difficult to ensure the necessary breathability for a breathable waterproof sheet used in building materials. Furthermore, the lower limit of the breathability resistance value is 0.03 m from a waterproofing standpoint. 2 It is preferable that the value is s·Pa / μg or higher.

[0033] The average visible light transmittance of the breathable waterproof sheet 1 for building materials in the 400-700nm range is 8% or higher. If the average visible light transmittance is less than 8%, sufficient brightness cannot be ensured indoors after construction, which may reduce work efficiency in the construction process after construction. Furthermore, the average ultraviolet light transmittance in the 280-400nm range is 2% or less, which is sufficient to maintain the long-term waterproofing performance of the breathable waterproof film layer 4. Moreover, a transmittance of 2% or less also suppresses the degradation of the nonwoven fabric layer 2 due to ultraviolet light.

[0034] The waterproofing performance of the breathable waterproof sheet 1 for building materials is preferably 5 to 120 kPa, and more preferably 6 to 110 kPa. If it is less than 5 kPa, the waterproofing performance may be insufficient, and if it is greater than 120 kPa, the breathability may be greatly impaired.

[0035] The thickness of the breathable waterproof sheet 1 for building materials is preferably 70 to 250 μm, and more preferably 100 to 180 μm. In this invention, a film thickness of 50 μm or more is required, so if the combined thickness of the nonwoven fabric layer and breathable adhesive layer is less than 70 μm, the strength may be insufficient, and if it is thicker than 250 μm, it may become hard and impair workability.

[0036] An example of a method for manufacturing the breathable waterproof sheet 1 for building materials of the present invention is described below. In the manufacturing method of this embodiment, one example is to first provide a breathable adhesive resin layer 3 on a nonwoven fabric layer 2 and then laminate a moisture-permeable waterproof film layer 4. Furthermore, another example is to provide a breathable adhesive resin layer 3 on a nonwoven fabric layer 2, laminate a moisture-permeable waterproof film layer 41, then provide a breathable adhesive resin layer 5 on the surface of the moisture-permeable waterproof film layer 41 and bond a moisture-permeable waterproof film layer 42 to it. [Examples]

[0037] The present invention will be specifically described by the following examples and comparative examples of the breathable waterproof sheet 1 for building materials, but the present invention is not limited to these. The physical properties of the examples and comparative examples were measured and evaluated using the following methods.

[0038] <Moisture permeability (moisture resistance value)> The measurement was performed in accordance with JIS A6111 7.2 Moisture permeability. The cup used was the one shown in Figure 2 of the JIS standard for moisture permeability testing.

[0039] <Thickness> The thickness of each layer was measured using a thickness measuring instrument G-6 (manufactured by Ozaki Seisakusho Co., Ltd., measuring terminal anvil Φ5 flat, measuring force 1.8N or less).

[0040] <Visible light average transmittance> Using a spectrophotometer (UV-3600, manufactured by Shimadzu Corporation), the visible light transmittance in the range of 400 to 700 nm was measured at 5 nm intervals, and the average value was calculated.

[0041] <Average ultraviolet transmittance> Using a spectrophotometer (UV-3600, manufactured by Shimadzu Corporation), ultraviolet light transmittance in the range of 280-400 nm was measured at 5 nm intervals, and the average value was calculated.

[0042] <Waterproof> The waterproof performance (unit: kPa) of breathable waterproof film layers and breathable waterproof sheets for building materials was determined in accordance with JIS A6111 7.5 Waterproofing. Waterproof performance was measured using Method B (high water pressure method). The pressure applied to the water pressure was the side facing the outside air during construction.

[0043] <Tensile strength> The test was conducted in accordance with JIS K7127. The test specimen was type 2, with a width of 25 mm, a length of 150 mm, a chuck spacing of 50 mm, and a tensile speed of 100 mm / min. The strength was measured under these conditions, and the average value was calculated.

[0044] <Tensile elongation at breaking> The material was pulled until it broke under the same conditions as the tensile strength test, and the average elongation at the time of breakage was calculated.

[0045] <Waterproof durability evaluation> A breathable waterproof membrane was subjected to a 4-month outdoor exposure test. For the exposure, the membrane was secured to a plywood board erected vertically facing south using a staple gun, and the edges of the membrane were further sealed with waterproof tape to prevent rainwater from entering the underside. The estimated amount of ultraviolet energy was 110 ± 4 MJ / m². 2 Subsequently, the aforementioned waterproofing test was performed. Furthermore, the samples after the exposure test were subjected to heat treatment using a forced-air constant-temperature incubator (DKM600, manufactured by Yamato Scientific Co., Ltd.) at 90°C for 7 weeks with an air exchange rate of 50-70 times / hour, and then to waterproofing tests after 17 weeks of heat treatment. Furthermore, to simulate a regularly occurring high-humidity environment, the moisture-permeable waterproof sheet for building materials used as a measurement sample was removed from the constant-temperature incubator with forced air once a week, and the surface of the side facing the exterior wall was moistened by spraying water. The spray volume was 50-80 g / m². 2 The evaluation criteria were as follows: 20kPa or higher: ○ 8kPa or more but less than 20kPa: △ Less than 8kPa: ×

[0046] <Indoor workability> A cube with sides of 2m was constructed using wooden prisms. Sheets were then attached to the five sides of the cube (excluding the floor) without any gaps using adhesive tape. The workability was evaluated according to the following criteria, showing whether a worker with 1.5 vision could recognize the text on a document (font size 11, Mincho black) from a distance of 40cm inside the cube. Characters are easily recognizable: ○ The text is difficult to read but recognizable: △ Characters cannot be recognized: ×

[0047] [Example 1] For a resin pellet containing 40% by weight of linear low-density polyethylene resin (Novatec LL UF-442: manufactured by Nippon Polyethylene Co., Ltd., melting point 123℃, density 0.924, melt flow rate 1.7), the following are added: 9.5% by weight of low-density polyethylene resin (Novatec LD LF-240: manufactured by Nippon Polyethylene Co., Ltd., melting point 114℃, density 0.924, melt flow rate 0.7), 49% by weight of heavy calcium carbonate inorganic particles (KS-800: manufactured by Calfine Co., Ltd., average particle size 2.8 μm), 1% by weight of titanium dioxide inorganic particles (JR-403: manufactured by Teika Co., Ltd., average particle size 0.25 μm), and 0.1% by weight of UV absorber (ADEKA Stab 1413: manufactured by ADEKA Corporation), and light stabilizer (ADEKA Stab LA-63P: manufactured by [Company Name] Co., Ltd.]. 0.2% by weight of ADEKA Corporation's product, 0.1% by weight of a primary antioxidant (ADEKA Stab AO-60: ADEKA Corporation), and 0.1% by weight of a secondary antioxidant (ADEKA Stab 2112: ADEKA Corporation) were added and mixed in a tumbler mixer. After mixing, the mixture was dissolved and kneaded at 210°C in a co-rotating twin-screw extruder, homogenized, and extruded as a film using a T-die. The film was then stretched 3.5 times in the length direction to obtain a white, breathable, waterproof film with a thickness of 80 μm. The moisture resistance value of the obtained breathable, waterproof film was 0.12 m / s. 2 The value was s·Pa / μg. Other physical properties are shown in Table 1.

[0048] The resulting breathable waterproof film and polyester spunbond nonwoven fabric (20457FLV: manufactured by Unitika Ltd., basis weight 45g / m²) 2The two materials were bonded together via an ethylene vinyl acetate-based hot melt resin to obtain the desired breathable waterproof sheet for building materials. The amount of hot melt resin applied was 6 g / m². 2 The material was then melt-extruded in a spiderweb pattern and bonded at 112°C under a pressure of 3 kgf. The resulting hot-melt resin layer was 15 μm thick. The evaluation results of the obtained breathable waterproof sheet for building materials are shown in Table 1.

[0049] [Example 2] The same polyethylene resin mixture as in Example 1 was extruded using a T-die, and then the film was stretched 3.5 times in the length direction to obtain a white, breathable, waterproof film with a thickness of 30 μm. A breathable waterproof sheet for building materials was obtained in the same manner as in Example 1, except that two layers of the obtained breathable waterproof film were laminated. The breathable waterproof films were bonded together using the same hot melt resin used when bonding the nonwoven fabric in Example 1, at a rate of 4 g / m². 2 The mixture was applied and subjected to a pressure of 3 kgf at 112°C. The resulting breathable waterproof sheet for building materials consisted of two layers of breathable waterproof film, with a total film thickness of 60 μm and a hot-melt resin layer of 10 μm between the films. The physical properties and evaluation results are shown in Table 1.

[0050] [Example 3] This mixture consists of 56% by weight of linear low-density polyethylene resin (Novatec LL UF-442: manufactured by Nippon Polyethylene Co., Ltd., melting point 123°C, density 0.924, melt flow rate 1.7), 42.5% by weight of heavy calcium carbonate inorganic particles (KS-800: manufactured by Calfine Co., Ltd., average particle size approximately 2.8 μm), 1% by weight of titanium dioxide inorganic particles (JR-403: manufactured by Teika Co., Ltd., average particle size 0.25 μm), and an ultraviolet absorber (ADEKA Stab 1413: manufactured by ADEKA Corporation). 0.1% by weight of ) was added, 0.2% by weight of a light stabilizer (ADEKA stab LA-63P: manufactured by ADEKA Corporation), 0.1% by weight of a primary antioxidant (ADEKA stab AO-60: manufactured by ADEKA Corporation), and 0.1% by weight of a secondary antioxidant (ADEKA stab 2112: manufactured by ADEKA Corporation). The mixture was kneaded in the same manner as in Example 1, the film was extruded using a T-die, and stretched to obtain a white, breathable, waterproof film with a thickness of 60 μm. The obtained breathable waterproof film was laminated with a nonwoven fabric in the same manner as in Example 1 to obtain a breathable waterproof sheet for building materials. The physical properties and evaluation results are shown in Table 1.

[0051] [Example 4] A white, breathable waterproof sheet for building materials was obtained using the same method as in Example 3, except that the thickness of the breathable waterproof film was set to 80 μm. The physical properties and evaluation results are shown in Table 1.

[0052] [Example 5] A breathable waterproof sheet for building materials was obtained by forming two layers of breathable waterproof film in the same manner as in Example 2, except that the thickness of the breathable waterproof film in Example 2 was set to 45 μm. The physical properties and evaluation results are shown in Table 1.

[0053] [Example 6] On the surface of the breathable waterproof film of the breathable waterproof sheet for building materials prepared in Example 2, polyester spunbond nonwoven fabric (Acstar N1030: manufactured by Toray Industries, Inc., basis weight 30g / m²) was applied. 2 The two materials were bonded together. The bonding conditions were the same as those for bonding breathable waterproof films together to obtain a breathable waterproof sheet for building materials. The physical properties and evaluation results are shown in Table 1.

[0054] [Example 7] On the surface of the breathable waterproof film of the breathable waterproof sheet for building materials prepared in Example 3, polyester spunbond nonwoven fabric (Acstar N1030: manufactured by Toray Industries, Inc., basis weight 30g / m²) was applied. 2 The two materials were bonded together. The bonding conditions were the same as those for bonding breathable waterproof films together to obtain a breathable waterproof sheet for building materials. The physical properties and evaluation results are shown in Table 1.

[0055] [Comparative Example 1] A breathable waterproof sheet for building materials was obtained in the same manner as in Example 1, except that the heavy calcium carbonate inorganic particles were changed to 49.7% by weight and titanium dioxide inorganic particles to 0.3% by weight, no UV absorbers, light stabilizers, or antioxidants were added, and the thickness of the breathable waterproof film was set to 60 μm. The physical properties and evaluation results are shown in Table 1.

[0056] [Comparative Example 2] A breathable waterproof sheet for building materials was obtained in the same manner as in Example 1, except that the thickness of the breathable waterproof film was set to 30 μm. The physical properties and evaluation results are shown in Table 1.

[0057] [Comparative Example 3] To a resin pellet containing 99.8% by weight of polypropylene resin (Novatec PP FL203D: manufactured by Nippon Polypropylene Co., Ltd., melting point 160-165°C, density 0.90, melt flow rate 3.0), 0.1% by weight of a UV absorber (ADEKA Stab 1413: manufactured by ADEKA Corporation) and 0.1% by weight of a light stabilizer (ADEKA Stab LA-63P: manufactured by ADEKA Corporation) were added. After mixing in a tumbler mixer, the mixture was melted and kneaded at 250°C in a co-rotating twin-screw extruder, homogenized, and extruded as a film using a T-die. After cooling, the film was stretched 4.5 times in the length direction on a stretching roll at 130°C, and then stretched 8 times in the width direction at 160°C to obtain a biaxially oriented polypropylene film with a thickness of 20 μm. An aluminum vapor-deposited film was formed on the obtained biaxially oriented polypropylene film by vacuum deposition. Then, through holes with a diameter of 0.5 mm were formed in both the vertical and horizontal directions at intervals of 1.5 mm by punching, resulting in an aluminum vapor-deposited polypropylene film with an opening ratio of 13%. The obtained aluminum vapor-deposited polypropylene film was then coated with ethylene vinyl acetate-based hot melt resin at a rate of 4 g / m² on the surface of the moisture-permeable waterproof film of the moisture-permeable waterproof sheet for building materials prepared in Comparative Example 2. 2 The material was applied in a spiderweb pattern and bonded together at 110°C under a pressure of 3 kgf to obtain the desired breathable waterproof sheet for building materials. The physical properties and evaluation results are shown in Table 1.

[0058] [Table 1]

[0059] As shown in Table 1, the breathable waterproof sheet according to the example exhibited excellent breathability and waterproofing properties, suppressed deterioration even when exposed to sunlight for a long period of time, and maintained high waterproofing performance for a long period of time even after being installed inside the exterior wall. [Explanation of symbols]

[0060] 1. Breathable waterproof sheet for building materials 2 non-woven layers 3. Breathable adhesive resin layer 4. Breathable waterproof film layer 41 Breathable waterproof film 42 Breathable waterproof film 5. Breathable adhesive resin layer

Claims

1. A breathable waterproof sheet for building materials, comprising a nonwoven fabric layer, a breathable adhesive resin layer, and a breathable waterproof film layer, The total thickness of the breathable waterproof film used in the breathable waterproof film layer is 50 to 100 μm. Furthermore, the average ultraviolet transmittance of the breathable waterproof film layer at 280-400 nm is 2% or less. In a breathable waterproof sheet for building materials, the water vapor resistance value measured in accordance with JIS A6111 was 0.19 m ２ - The radiation level is s・Pa / μg or less, the average visible light transmittance in the 400-700 nm range is 8% or more, and the average ultraviolet light transmittance in the 280-400 nm range is 2% or less. Breathable waterproof sheet for building materials.

2. The breathable waterproof sheet for building materials according to claim 1, wherein the breathable waterproof film layer is formed by two breathable waterproof films with a breathable adhesive resin layer in between.

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