Roofing underlayment material

Abstract

To provide a roofing underlayment material which is light in weight, high in strength, free from softening and stickiness in summer, free from hardening and cracking in winter, and excellent in workability over a wide temperature range.SOLUTION: A roofing underlayment material comprises a first nonwoven fabric layer 2 comprising a polyolefin-based synthetic fiber and / or a polyester-based synthetic fiber, a first water cut-off layer 3 provided under the first nonwoven fabric layer 2 and comprising a polyolefin-based synthetic resin, a second nonwoven fabric layer 4 comprising a polyolefin-based synthetic fiber and / or a polyester-based synthetic fiber provided under the first water cut-off layer 3, and a second water cut-off layer 5 comprising a polyolefin-based synthetic resin provided under the second nonwoven fabric layer 4; the basis weight of the nonwoven fabric constituting the first nonwoven fabric layer 2 is in the range of 65 to 100 g / m2, the basis weight of the nonwoven fabric constituting the second nonwoven fabric layer 4 is in the range of 30 to 100 g / m2, the basis weight of the synthetic resin constituting the first water cut-off layer 3 is in the range of 25 to 50 g / m2, and the basis weight of the synthetic resin constituting the second water cut-off layer 5 is in the range of 70 to 200 g / m2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to roofing underlayment. [Background technology]

[0002] The roof of a house is covered with roofing materials such as tiles, slates, Colonial (registered trademark), and metal sheets. However, it is difficult to completely prevent rainwater from entering using roofing materials alone. Therefore, waterproofing is improved by laying roofing underlayment materials such as asphalt roofing (JIS-A6005 regulations) and rubber-modified asphalt roofing (JIS-A6013 regulations) between the sheathing board and the roofing material. Base paper and rolls of raw material have traditionally been used as the substrate. Base paper is paper made by beating and straining natural fibers such as wool, cotton, waste paper such as newspapers and magazines, and wood chips, and rolls of raw material are nonwoven fabrics made of synthetic fibers, and there are dry and wet methods.

[0003] The above asphalt roofing underlayment has a weight of approximately 1kg / m 2 Asphalt roofing is heavy, making it difficult to lift onto the roof and also causing problems such as the hands and subfloor boards easily becoming dirty from the asphalt. In addition, as the base material of asphalt roofing has a paper-like quality, it has poor tensile properties, especially low tear strength. Furthermore, as roofing underlayment is installed outdoors, it can soften or become sticky due to the heat from the sun in summer. It can also harden or crack due to the cold in winter.

[0004] Patent Document 1 describes this asphalt roofing underlay material as "an asphalt roofing material formed by impregnating and coating a base material with asphalt, the base material being a sheet produced by a wet process from main raw materials in the range of 5 to 40% by weight of binder fiber, 5 to 50% by weight of polyester fiber, and 30 to 90% by weight of organic natural fiber."

[0005] However, with the asphalt roofing underlayment described in Patent Document 1, although the tear strength is improved somewhat, since the base material is impregnated with asphalt, it remains heavy, and the problems of softening and stickiness in summer as well as hardening and cracking in winter remain unresolved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-164478 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above-mentioned problems of the conventional technology and aims to provide a roofing underlayment material that is lightweight, has high strength, does not soften or become sticky in the summer, does not harden or crack in the winter, and has excellent workability over a wide temperature range. [Means for solving the problem]

[0008] In order to solve the above problems, the roofing underlay material of the first invention of the present application is a roofing underlay material comprising a first nonwoven fabric layer made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers, a first water-stopping layer made of polyolefin-based synthetic resin provided under the first nonwoven fabric layer, a second nonwoven fabric layer made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers provided under the first water-stopping layer, and a second water-stopping layer made of polyolefin-based synthetic resin provided under the second nonwoven fabric layer, wherein the basis weight of the nonwoven fabric constituting the first nonwoven fabric layer is 65 to 100 g / m 2 The weight of the nonwoven fabric constituting the second nonwoven fabric layer is in the range of 30 to 100 g / m 2 The weight of the polyolefin synthetic resin constituting the first water blocking layer is in the range of 25 to 50 g / m 2 The weight of the polyolefin synthetic resin constituting the second water-stopping layer is in the range of 70 to 200 g / m 2The range is characterized in that

[0009] The second invention of the present application is characterized in that in the first invention of the present application, the first water stopping layer and the second water stopping layer are polyethylene laminate layers.

[0010] The third invention of the present application is characterized in that, in the first or second invention of the present application, the nonwoven fabric of the first nonwoven fabric layer is a needle-punched nonwoven fabric made of polypropylene, and the nonwoven fabric of the second nonwoven fabric layer is a spunbond nonwoven fabric made of polyethylene terephthalate.

[0011] The fourth invention of the present application is characterized in that, in the third invention of the present application, the nonwoven fabric constituting the first nonwoven fabric layer has a tensile strength of 140 N / cm or more in the length direction and 80 N / cm or more in the width direction, and a tear strength of 15 N or more in the length direction and 20 N or more in the width direction, and the nonwoven fabric constituting the second nonwoven fabric layer has a tensile strength of 100 N / cm or more in the length direction and 40 N / cm or more in the width direction, and a tear strength of 5 N or more in the length direction and 5 N or more in the width direction. Effect of the Invention

[0012] According to the first, second and third inventions of the present application, the nonwoven fabric and resin are used, so that the nonwoven fabric and resin are lightweight and easy to apply. According to the fourth invention of the present application, the nonwoven fabric and resin have sufficient strength so that the nonwoven fabric and resin are not easily torn even in strong winds. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view of a roofing underlayment material according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating a method for determining tear strength. [Diagram 3] FIG. 3 is a diagram illustrating a method for determining the tear strength. [Figure 4] FIG. 4 is a diagram for explaining a method for determining the nail hole sealing performance. [Diagram 5] FIG. 5 is a diagram explaining the slipperiness test method in accordance with JISA1454:2016. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. However, various modifications and alterations are possible without departing from the technical scope of the present invention.

[0015] A roofing underlayment according to an embodiment of the present invention will be described with reference to Fig. 1. As shown in Fig. 1, the roofing underlayment 1 of this embodiment includes a first nonwoven fabric layer 2 made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers, a first water-stopping layer 3 made of polyolefin-based synthetic resin provided under the first nonwoven fabric layer 2, a second nonwoven fabric layer 4 made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers provided under the first water-stopping layer 3, and a second water-stopping layer 5 made of polyolefin-based synthetic resin provided under the second nonwoven fabric layer 4.

[0016] Specifically, the polyolefin synthetic fibers that can be used include synthetic fibers made of polyolefin resins such as polyethylene, polypropylene, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and ethylene-vinyl acetate copolymer, polyolefin thermoplastic elastomers using ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, and soft polyolefin resins containing amorphous polyolefins, etc. These synthetic fibers may be used alone or as a mixture of two or more kinds.

[0017] As the polyester-based synthetic fiber, there can be used synthetic fibers made of polyester-based thermoplastic elastomers using polyethylene terephthalate, polymethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc., soft polyester resins containing amorphous polyester, etc. These synthetic fibers may be used alone or as a mixture of two or more kinds.

[0018] The manufacturing method of the nonwoven fabric made of polyolefin synthetic fibers and the nonwoven fabric made of polyester synthetic fibers is not particularly limited, and nonwoven fabrics manufactured by known manufacturing methods such as chemical bonding, thermal bonding, needle punching, stitch bonding, spun lace, spun bonding, melt blowing, wet method, etc. can be used. In particular, needle punched nonwoven fabrics formed by "opening and stirring relatively long short fibers with an air flow and sending them out onto a belt conveyor, sending out a certain amount of fibers in a certain direction with the needles of a music box-like drum of a carding machine installed along the way to form a web, stacking the formed webs in several layers, and entangling the fibers with tiny protrusions called barbs by reciprocating special needles at high speed on the stacked layers" are strong and non-slip, and polypropylene does not absorb moisture at all, so polypropylene needle punched nonwoven fabrics are preferable as the nonwoven fabric of the first nonwoven fabric layer. In addition, spunbond nonwoven fabrics formed by "heating and melting a resin with a low melting temperature, directly spinning the molten resin extruded from a nozzle, overlapping several of the endless long fibers discharged on a belt conveyer to form a web, and heat welding the formed web with a heated roll" have high strength, and polyethylene terephthalate has excellent heat resistance, cold resistance, and water resistance, so polyethylene terephthalate spunbond nonwoven fabrics are preferred as the nonwoven fabric for the second nonwoven fabric layer.

[0019] The nonwoven fabric used in the first nonwoven fabric layer 2 preferably has a tensile strength of 140 N / cm or more in the length direction and 80 N / cm or more in the width direction, and a tear strength of 15 N or more in the length direction and 20 N or more in the width direction, while the nonwoven fabric used in the second nonwoven fabric layer 4 preferably has a tensile strength of 100 N / cm or more in the length direction and 40 N / cm or more in the width direction, and a tear strength of 5 N or more in the length direction and 5 N or more in the width direction. If the strength is less than this range, the laminated roofing material 1 may tear or break when applied to the roof surface. In addition, when the roofing material 1 is applied to the roof surface and then walked on, it may tear due to the load applied or tear from the staple nails used for fastening. Therefore, the basis weight of the nonwoven fabric constituting the first nonwoven fabric layer is set to 65 to 100 g / m 2 It is preferable that the thickness is within the range of 65 g / m 2If it is less than 100 g / m, sufficient strength may not be obtained. 2 If the weight exceeds 100 g / m2, not only will it be difficult to roll up the roofing material 1, but it will also become heavy and workability will be impaired. 2 It is preferable that the thickness is within the range of 30 g / m 2 If it is less than 100 g / m, sufficient strength may not be obtained. 2 If the thickness exceeds this value, not only will it be difficult to roll up the roofing material 1, but it will also become heavy and workability will be easily impaired.

[0020] The polyethylene laminate layer is made of a general polyethylene resin and is not particularly limited. Specifically, polyethylene such as high density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene, and metallocene polymerized polyethylene can be used alone or in combination of two or more kinds. In addition, the polyethylene laminate layer can be obtained by extrusion lamination, dry lamination, or wet lamination. In particular, when the total weight of the second polyethylene laminate layer, which is a water-stopping layer, is 100% by weight, by blending 1 to 5% by weight of an ultraviolet absorber, a light stabilizer, and an antioxidant in this polyethylene laminate layer, it is expected to prevent deterioration due to ultraviolet rays during construction of the first and second water-stopping layers made of polyethylene laminate and deterioration due to heat over a long period of time.

[0021] Furthermore, the weight of the polyethylene that constitutes the first water-stopping layer is 25 to 50 g / m 2 It is preferable that the thickness is in the range of 20 g / m 2 If it is less than 50 g / m, there is a problem of reduced water-stopping power. 2 If it exceeds 100 g / m2, not only will it be difficult to roll up the roofing underlayment material 1, but it will also become heavy, and workability will be easily impaired. 2 It is preferable that the thickness is in the range of 70 g / m 2 If it is less than 200 g / m, there is a problem of reduced water-stopping power. 2If it is too thick, not only will it be difficult to roll up the roofing underlayment material 1, but it will also become heavy, which will tend to impair workability.

[0022] The weight of roofing underlayment 1 is 190~450g / m 2 is preferable, and 200 to 300 g / m 2 More preferably, 190 g / m 2 If it is less than 450 g / m, the roofing material 1 may be easily turned up by the wind during construction, which may impair construction. 2 If the weight exceeds this limit, it may affect transportability and workability. The weight of a typical asphalt-based roofing underlayment is 1000g / m 2 Therefore, the roofing underlayment material 1 of the present invention has the advantage of being able to weigh less than half that amount.

[0023] The total thickness of the roofing underlayment material 1 is preferably 300 to 600 μm. If the total thickness is less than 300 μm, the strength required as a roofing underlayment material may not be maintained, and if it exceeds 600 μm, the roofing underlayment material 1 itself may become too stiff and difficult to bend, making it difficult to work on the ridges, valleys, and rising parts.

[0024] It is preferable that the tensile strength of the roofing underlayment 1 is 60 N / cm or more in the length direction and 40 N / cm or more in the width direction, and the tear strength is 25 N or more in the length direction and 30 N or more in the width direction. If the strength is below these values, there is a risk that the roofing underlayment will break when applied to the sheathing board surface, that it will break when walking on it, or that tears will occur from the nailing parts used to fasten it to the sheathing board.

[0025] As a manufacturing method of the roofing underlayment 1 according to this embodiment, a method of laminating the second water stopping layer made of polyolefin synthetic resin, the second nonwoven fabric layer, the first water stopping layer made of polyolefin synthetic resin, and the first nonwoven fabric layer by thermal fusion can be used. Also, a method of laminating the second water stopping layer made of polyolefin synthetic resin and the second nonwoven fabric layer, the first water stopping layer made of the second nonwoven fabric layer and polyolefin synthetic resin, and the first water stopping layer made of polyolefin synthetic resin and the first nonwoven fabric layer with an adhesive can be used.

[0026] Usable adhesives include vinyl resins, urethane resins, silicone resins, acrylic resins, epoxy resins, ester resins, etc. Acrylic resins are particularly preferred in terms of ease of handling during processing and cost.

[0027] Various additives may be added to the polyethylene of the present invention as long as they do not impair the object of the present invention. Examples of additives include colorants such as inorganic pigments, organic pigments, and dyes, flame retardants, antistatic agents, antioxidants, ultraviolet absorbers, lubricants, crosslinking agents, conductive agents, antibacterial and antifungal agents, plasticizers, silicones, compatibilizers, reinforcing agents, and fillers. EXAMPLES

[0028] Although the present invention will be described below with reference to exemplary embodiments, various modifications and alterations are possible without departing from the technical scope of the present invention.

[0029] A polyethylene terephthalate spunbond nonwoven fabric (40 g / m2) was produced by the spunbond method, which is a well-known method for producing nonwoven fabrics. 2 A laminate layer of low-density polyethylene (100 g / m) was applied to one side of the second nonwoven fabric layer by a T-die extrusion method. 2 A second water stop layer made of a needle-punched nonwoven fabric (70 g / m) made of polypropylene staple fibers produced by a needle punch method, which is a known method for producing nonwoven fabrics, was formed on the surface of the second nonwoven fabric layer opposite to the surface on which the second water stop layer was formed. 2) and a laminate layer (30 g / m2) of low-density polyethylene with weather-resistant agent added thereto by the T-die extrusion method. 2 ) is placed between the first waterproof layer and the second waterproof layer, which is about 0.42 mm thick and has a basis weight of 240 g / m 2 Thus, the roofing underlayment of the present invention was obtained. By using a needle-punched nonwoven fabric of short polypropylene fibers for the first nonwoven fabric layer, the roofing underlayment of the present invention is less slippery when standing on it, and while long-fiber nonwoven fabrics are prone to fiber twisting that can get caught on shoes and cause tripping or falling, short fibers do not cause fiber twisting, making it possible to work safely. In other words, by using a needle-punched nonwoven fabric of short polypropylene fibers for the first nonwoven fabric layer, it is possible to enjoy the advantages of anti-slip and anti-tripping properties.

[0030] (1) Weight The weights of the roofing underlayment materials of the examples of the present invention obtained as described above and asphalt-based roofing underlayment materials are compared in Table 1 below.

[0031] [Table 1]

[0032] As shown in Table 1, the roofing underlayment of the present invention is extremely light, weighing only about 1 / 4 of that of a typical asphalt-based roofing underlayment. Therefore, it is expected that the construction and work will be simple and safe. Furthermore, the physical properties of the roofing underlayment of the embodiment of the present invention obtained as described above are shown in Table 2 below.

[0033] [Table 2]

[0034] Since there are no standard values ​​for the physical properties of resin-based roofing underlayment materials, the evaluation method for the physical properties in Table 2 is based on the standard number ARK04 of the Japan Waterproofing Materials Association. SThe evaluation method for each physical property is explained below. (1) Tensile strength A test piece (length 200mm, width 50mm) was attached to the tensile testing machine so that the grip interval was 100mm, and the test piece was pulled at a speed of 100mm / min until it broke, and the maximum load was determined. However, if the test piece broke within 10mm from the grip during the test, that test piece was excluded and a new test piece was added. The tensile strength (N / cm) was calculated using the following formula and expressed as the average value of five test pieces. T=P / W Here, T is the tensile strength (N / cm), P is the maximum load (N), and W is the width of the test piece (cm). The tensile strength after heat treatment was measured by placing a test piece (length 200 mm, width 50 mm) on a wire mesh in a heating incubator (JIS K6257) at 70°C ± 3°C for 168 hours, then removing it and cooling it to room temperature, and testing it using the same method. The tensile strength was expressed as the average value of five test pieces.

[0035] (2) Heat resistance The test pieces (200 mm long, 200 mm wide) were suspended in a heating incubator (JIS K6257) at 70°C ± 3°C for 2 hours, then removed and inspected for any slippage of the coating, foaming, or seepage of the permeated resin.

[0036] (3) Tear strength As shown in Fig. 2, a 75 mm slit 7 was made in the center of a test piece (length 100 mm, width 50 mm) 6 parallel to the long side to create two tongues, and 45 mm from each end was used as a gripping margin. As shown in Fig. 3, one side 6a of the test piece 6 was attached to a tensile tester 8 so that the gripping distance was 50 mm, and the other side 6b of the test piece 6 was attached to the tensile tester 8. The test piece 6 was pulled at a speed of 100 mm / min until it broke, and the maximum load was determined. The tear strength (N) was expressed as the average value of five test pieces.

[0037] (4) Nail hole sealing ability As shown in Figure 4, at 20°C, a test piece (length 90 mm, width 90 mm) 10 was placed on a square waterproof plywood 9 (thickness 12 mm) with a length of 100 mm and a width of 100 mm, and a ring nail 11 (diameter 3.2 mm, length 32 mm) was hammered straight into the test piece 10 until the nail head was about 10 mm above the test piece 10 to prepare a ring nail test piece. A PVC pipe 12 with an inner diameter of 30 to 40 mm was erected on the test piece and a seal 13 was applied around it. After the seal 13 hardened, a liquid 14 made by adding an appropriate amount of ink to water and stirring it was poured into the PVC pipe 12 up to a water head of 30 mm. After leaving it for 24 hours, the presence or absence of water leakage through the penetrating nail 11 was confirmed. If no water leakage through the penetrating nail 11 was found, the liquid was removed and the test piece was left for another 24 hours, and the condition of the base of the nail hole part was confirmed. If no water leakage was found, this refers to the case where the following 1) and 2) are satisfied. 1) The substrate was not wet in 8 or more of the 10 test pieces. 2) Water should not leak through the penetrating nails to the back of the substrate.

[0038] (5) Bending resistance Using a steel round bar 20 mm in diameter and 50 mm in length, a low-temperature constant temperature bath (capable of adjusting the liquid or air temperature to a set temperature ±1°C) and a heating incubator (capable of adjusting the temperature to 70°C ±3°C) were used. The test piece (length 250 mm, width 25 mm) and the above round bar were left to stand in the low-temperature constant temperature bath with the air temperature set to -10°C ±1°C for more than one hour, then removed and immediately placed against the round bar and bent 180 degrees in two seconds to check whether cracks occurred on the surface of the test piece. The bending resistance after heat treatment was evaluated by leaving a test piece (length 250 mm, width 25 mm) on a wire mesh in a heating incubator adjusted to 70°C ± 3°C for 168 hours, then removing the test piece from the heating incubator and cooling it to room temperature, and then leaving it to stand for at least 1 hour in a low-temperature incubator with the air temperature set to -5°C ± 1°C, after which it was removed and immediately placed against a round bar and bent 180 degrees in 2 seconds to check whether cracks occurred on the surface of the test piece.

[0039] (6) Dimensional stability Using a heating incubator (capable of adjusting the temperature to 60°C±3°C) and a thermostatic water bath (capable of adjusting the water temperature to 60°C±1°C), a test piece (length 300 mm, width 50 mm) was placed horizontally on a wire mesh in the heating incubator adjusted to 60°C±3°C for 24 hours, after which the test piece was removed from the heating incubator and cooled to room temperature, and the length of the test piece was immediately measured to within 0.1 mm to determine the reference length, the test piece was then immersed in a thermostatic water bath adjusted to 60°C±1°C for 24 hours, after which it was removed and the length of the test piece was measured to within 0.1 mm to determine the difference from the reference length (first differential length), and then the test piece was placed horizontally on a wire mesh in the heating incubator adjusted to 60°C±3°C for 24 hours, after which it was removed and the length of the test piece was measured to within 0.1 mm to determine the difference from the reference length (second differential length). This test was repeated five times, and the maximum value among the average value of the first difference length (mm) and the average value of the second difference length (mm) was determined as the dimensional stability (mm).

[0040] 《High strength》 As shown in Table 2, the roofing underlayment of the present invention has extremely high tensile strength and tear strength. On the other hand, current asphalt-based roofing underlayment materials have the problem that they are easily torn and blown away by the wind when installed in strong winds. The roofing underlayment of the present invention has extremely high tensile strength and tear strength, so such problems do not occur even when installed in strong winds.

[0041] <Workability at high temperatures> As shown in Table 2, the roofing underlayment of the present invention has excellent heat resistance. On the other hand, current asphalt-based roofing underlayment materials have the problem that they become soft and sticky when installed at high temperatures such as in the summer, causing stains on shoes, work clothes, etc. The roofing underlayment of the present invention has excellent heat resistance, so it does not soften or become sticky even at high temperatures, and shoes, work clothes, etc. do not get dirty.

[0042] <Workability at low temperatures> As shown in Table 2, the roofing underlayment of the present invention does not harden even at low temperatures, and does not crack when bent, as can be seen from the bending resistance test results. On the other hand, current asphalt-based roofing underlayment materials have the problem that they harden when installed at low temperatures, such as in winter, and crack when bent. The roofing underlayment of the present invention does not harden even at low temperatures, and does not crack when bent.

[0043] 《Waterstop property for nail holes》 As shown in Table 2, the roofing underlayment of the present invention has excellent nail hole waterproofing properties, as can be seen from the nail hole sealing property test results.

[0044] 《Dimensional stability》 As shown in Table 2, the roofing underlayment of the present invention has excellent dimensional stability, as can be seen from the dimensional stability test results.

[0045] 《Slip resistance》 Roofing underlayment applied on roofs requires anti-slip properties for safety. Therefore, a slip test was conducted for the asphalt-based roofing underlayment and the roofing underlayment of the present invention using a slip tester shown in FIG. 5 in accordance with JISA1454:2016. In FIG. 5, 21 is a constant speed motor, 22 is a reduction gear, 23 is a wire, 24 is a tension force speed adjustment device, 25 is a tension angle adjustment device, 26 is a load conversion device, 27 is an initial load adjustment device, 28 is a guide rail, 29 is a wheel for moving, 30 is a weight, 31 is a steel sliding piece base, 32 is a sliding piece, and 33 is a test piece. As a result, the slip resistance coefficient (CSR) of the roofing underlayment of the present invention was 0.57 in a dry state and 0.53 in a wet state. On the other hand, the CSR of the asphalt-based roofing underlayment was 0.68 in a dry state and 0.63 in a wet state. The higher the CSR value, the less slippery the surface is. The dry state refers to the state where the surface of the test piece is wiped with a clean cloth, and the wet state refers to the state where tap water and test powder type 1 and type 7 specified in JIS Z 8901 are mixed in a mass ratio of 20:9:1 and 400 g / m 2 This refers to the state in which the powder is spread on the surface of the test piece in a ratio of

[0046] Meanwhile, the revised Barrier-Free Law of August 2012 states that "The coefficient of slip resistance (CSR) measured by the slipperiness test for flooring materials stipulated in JISA1454 (Testing method for polymer-based flooring materials) is used as an index of floor slipperiness," and according to the new Barrier-Free Law, the recommended CSR value for floors and road surfaces on which people move while wearing footwear is 0.4 or more. Therefore, it is clear that the roofing underlay material of the present invention has excellent slip resistance.

[0047] To summarize the above, it can be seen that the roofing underlayment of the present invention has the following advantages: Lightweight and non-slip, it is easy to install. Excellent workability at both high and low temperatures. Not easily torn even when installed in strong winds. Excellent water-tightness of nail holes, so there is no rain leakage from installed areas. Dimensional change is extremely small. [Explanation of symbols]

[0048] 1. Roofing materials 2 First nonwoven layer 3 First water-stopping layer 4 Second nonwoven layer 5 Second water-stopping layer

Claims

1. A roofing material comprising a first nonwoven fabric layer made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers, a first water-stopping layer made of polyolefin-based synthetic resin provided under the first nonwoven fabric layer, a second nonwoven fabric layer made of polyolefin-based synthetic fibers and / or polyester-based synthetic fibers provided under the first water-stopping layer, and a second water-stopping layer made of polyolefin-based synthetic resin provided under the second nonwoven fabric layer, wherein the basis weight of the nonwoven fabric constituting the first nonwoven fabric layer is 65 to 100 g / m ２ The weight of the nonwoven fabric constituting the second nonwoven fabric layer is in the range of 30 to 100 g / m ２ The weight per unit area of ​​the polyolefin synthetic resin constituting the first water blocking layer is in the range of 25 to 50 g / m ２ The weight of the polyolefin synthetic resin constituting the second water blocking layer is in the range of 70 to 200 g / m ２ A roofing underlayment material characterized in that the range.

2. 2. The roofing underlayment material according to claim 1, wherein the first water-stopping layer and the second water-stopping layer are polyethylene laminate layers.

3. 3. The roofing underlayment material according to claim 1, wherein the nonwoven fabric of the first nonwoven fabric layer is a needle-punched nonwoven fabric made of polypropylene, and the nonwoven fabric of the second nonwoven fabric layer is a spunbonded nonwoven fabric made of polyethylene terephthalate.

4. A roofing underlayment material as described in claim 3, characterized in that the nonwoven fabric constituting the first nonwoven fabric layer has a tensile strength of 140 N / cm or more in the length direction and 80 N / cm or more in the width direction, a tear strength of 15 N or more in the length direction and 20 N or more in the width direction, and the nonwoven fabric constituting the second nonwoven fabric layer has a tensile strength of 100 N / cm or more in the length direction and 40 N / cm or more in the width direction, and a tear strength of 5 N or more in the length direction and 5 N or more in the width direction.

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