Roofing underlay

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, according to the asphalt roofing underlayment described in Patent Document 1, even if the tear strength is somewhat improved, as long as 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, are not solved.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In view of the above problems of the prior art, the present invention is an improvement thereof, and an object of the present invention is to provide an underlayment for roofing that is lightweight, high-strength, free from softening and stickiness in summer, free from hardening and cracking in winter, and excellent in workability over a wide temperature range.

Means for Solving the Problems

[0008] In order to solve the above problems, the underlayment for roofing of the first invention of the present application comprises a first non-woven fabric layer made of a polyolefin-based synthetic fiber and / or a polyester-based synthetic fiber, a first water-stop layer made of a polyolefin-based synthetic resin provided under the first non-woven fabric layer, a second non-woven fabric layer made of a polyolefin-based synthetic fiber and / or a polyester-based synthetic fiber provided under the first water-stop layer, and a second water-stop layer made of a polyolefin-based synthetic resin provided under the second non-woven fabric layer. In the underlayment for roofing, the basis weight of the non-woven fabric constituting the first non-woven fabric layer is in the range of 65 to 100 g / m 2 and the basis weight of the non-woven fabric constituting the second non-woven fabric layer is in the range of 30 to 100 g / m 2 the basis weight of the polyolefin-based synthetic resin constituting the first water-stop layer is in the range of 25 to 50 g / m 2 and the basis weight of the polyolefin-based synthetic resin constituting the second water-stop layer is in the range of 70 to 200 g / m 2It is characterized by being within the range of.

[0009] The second invention of the present application is characterized in that in the first invention of the present application, the first water-stop layer and the second water-stop 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 non-woven fabric of the first non-woven fabric layer is a needle-punched non-woven fabric made of polypropylene, and the non-woven fabric of the second non-woven fabric layer is a spunbond non-woven 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 tensile strength of the non-woven fabric constituting the first non-woven fabric layer is 140 N / cm or more in the length direction and 80 N / cm or more in the width direction, the tear strength is 15 N or more in the length direction and 20 N or more in the width direction, and the tensile strength of the non-woven fabric constituting the second non-woven fabric layer is 100 N / cm or more in the length direction and 40 N / cm or more in the width direction, and the tear strength is 5 N or more in the length direction and 5 N or more in the width direction.

Advantages of the Invention

[0012] According to the first, second, and third inventions of the present application, since it is made of non-woven fabric and resin, it is lightweight and has excellent workability. According to the fourth invention of the present application, since it has sufficient strength, it is not easily torn even by strong winds.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

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

[0015] The 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 the present embodiment includes a first nonwoven fabric layer 2 made of a polyolefin synthetic fiber and / or a polyester synthetic fiber, a first water stop layer 3 made of a polyolefin synthetic resin provided under the first nonwoven fabric layer 2, a second nonwoven fabric layer 4 made of a polyolefin synthetic fiber and / or a polyester synthetic fiber provided under the first water stop layer 3, and a second water stop layer 5 made of a polyolefin synthetic resin provided under the second nonwoven fabric layer 4.

[0016] Specific examples of the polyolefin synthetic fiber 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 and ethylene-propylene-diene copolymer rubber, and soft polyolefin resins containing amorphous polyolefin. These synthetic fibers may be used alone or as a mixture of two or more.

[0017] Specific examples of the polyester synthetic fiber include synthetic fibers made of polyester thermoplastic elastomers such as polyethylene terephthalate, polymethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and soft polyester resins containing amorphous polyester. These synthetic fibers may be used alone or as a mixture of two or more.

[0018] The manufacturing method of the nonwoven fabric made of polyolefin synthetic fiber and the nonwoven fabric made of polyester synthetic fiber is not particularly limited, and nonwoven fabrics manufactured by known manufacturing methods such as chemical bonding, thermal bonding, needle punching, stitch bonding, spunlace, spunbond, meltblown, and wet method can be used. In particular, "relatively long staple fibers are opened and agitated by an air stream, sent out to a belt conveyor, and the fibers are sent out in a certain amount and in a certain direction by the needles of the orgel-shaped drum of the carding machine provided on the way to form a web. The formed webs are stacked in several layers, and the fibers are entangled with each other by minute protrusions called barbs by the reciprocating movement of special needles at high speed on the laminate." The needle-punched nonwoven fabric formed in this way has high strength and is not slippery. Since polypropylene does not absorb moisture at all, the polypropylene needle-punched nonwoven fabric is preferable as the nonwoven fabric of the first nonwoven fabric layer. Also, "a resin with a low melting temperature is heated and melted, the molten resin extruded from a nozzle is directly spun, and endless long fibers discharged are stacked on a belt conveyor to form a web, and the formed web is heat-welded with a heat roll." The spunbond nonwoven fabric formed in this way has high strength, and since polyethylene terephthalate is excellent in heat resistance, cold resistance, and water resistance, the polyethylene terephthalate spunbond nonwoven fabric is preferable as the nonwoven fabric of the second nonwoven fabric layer.

[0019] In addition, the nonwoven fabric used for the first nonwoven fabric layer 2 preferably has a tensile strength of 140 N / cm or more in the length direction, 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. The nonwoven fabric used for the second nonwoven fabric layer 4 preferably has a tensile strength of 100 N / cm or more in the length direction, 40 N / cm or more in the width direction, a tear strength of 5 N or more in the length direction, and 5 N or more in the width direction. If it is less than this strength, the laminated roofing material 1 may tear or break when being constructed on the roof surface. Also, after the roofing material 1 is constructed on the roof surface, if one walks on it, there is a risk of breakage due to the weight or tearing from the staple nails used for fastening. Therefore, the basis weight of the nonwoven fabric constituting the first nonwoven fabric layer is preferably in the range of 65 to 100 g / m 2 within the range. 65 g / m 2If it is less than that, there is a risk that sufficient strength cannot be obtained, and if it exceeds 100 g / m 2 not only does it become difficult to roll up the roofing material 1, but it also becomes heavy, and the workability is likely to be impaired. The basis weight of the non-woven fabric constituting the second non-woven fabric layer is preferably in the range of 30 to 100 g / m 2 . If it is less than 30 g / m 2 , there is a risk that sufficient strength cannot be obtained, and if it exceeds 100 g / m 2 , not only does it become difficult to roll up the roofing material 1, but it also becomes heavy, and the workability is likely to be impaired.

[0020] The polyethylene laminate layer is composed 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, metallocene-polymerized polyethylene, etc. can be used alone or in combination of two or more. Also, to obtain the polyethylene laminate layer, extrusion lamination, dry lamination, or wet lamination may be used. In particular, when the total weight of the second polyethylene laminate layer, which is the water stop layer, is 100% by weight, by blending 1 to 5% by weight of an ultraviolet absorber, a light stabilizer, and an antioxidant into this polyethylene laminate layer, the effects of preventing deterioration due to ultraviolet rays during the construction of the first water stop layer and the second water stop layer made of polyethylene laminate and preventing deterioration due to heat over a long period can be expected.

[0021] Furthermore, the basis weight of the polyethylene constituting the first water stop layer is preferably in the range of 25 to 50 g / m 2 . If it is less than 20 g / m 2 , there is a disadvantage of a decrease in water stopping performance, and if it exceeds 50 g / m 2 , there is a disadvantage that not only does it become difficult to roll up the underlay roofing material 1, but it also becomes heavy, and the workability is likely to be impaired. The basis weight of the polyethylene constituting the second water stop layer is preferably in the range of 70 to 200 g / m 2 . If it is less than 70 g / m 2 , there is a disadvantage of a decrease in water stopping performance, and if it exceeds 200 g / m 2If it is too thick, not only does the roofing underlayment 1 become difficult to roll up, but it also becomes heavy, and there is a problem that workability is likely to be impaired.

[0022] The weight of the roofing underlayment 1 is preferably 190 to 450 g / m 2 and more preferably 200 to 300 g / m 2 If it is less than 190 g / m 2 during construction, it may be affected by the wind, and the roofing material 1 may be easily lifted up, resulting in impaired workability. If it exceeds 450 g / m 2 there is a risk of affecting transportability and workability. Since the weight of a general asphalt-based roofing underlayment is about 1000 g / m 2 according to the roofing underlayment 1 of the present invention, there is an advantage that the weight can be reduced to less than half of that.

[0023] The total thickness of the roofing underlayment 1 is preferably 300 to 600 μm. If the total thickness is less than 300 μm, there is a risk that the strength as a roofing underlayment cannot be maintained. If it exceeds 600 μm, the roofing underlayment 1 itself becomes hard and difficult to bend, and there is a risk that construction of the ridge part, valley part, and rising part becomes difficult.

[0024] The tensile strength of the roofing underlayment 1 is preferably 60 N / cm or more in the length direction, 40 N / cm or more in the width direction, the tear strength is preferably 25 N or more in the length direction, and 30 N or more in the width direction. If these strengths are lower, there is a risk of tearing when constructing on the field floor surface, when walking on the roofing underlayment, or when tearing occurs from the nailing part used for fixing to the field floor.

[0025] As a method for manufacturing the roofing underlayment 1 according to this embodiment, a method of laminating a second water-stop layer made of a polyolefin synthetic resin, a second non-woven fabric layer, a first water-stop layer made of a polyolefin synthetic resin, and a first non-woven fabric layer by heat fusion can be used. Further, a method of laminating a second water-stop layer made of a polyolefin synthetic resin and a second non-woven fabric layer, a second non-woven fabric layer and a first water-stop layer made of a polyolefin synthetic resin, and a first water-stop layer made of a polyolefin synthetic resin and a first non-woven fabric layer with an adhesive can also be used.

[0026] As an adhesive that can be used, vinyl resins, urethane resins, silicone resins, acrylic resins, epoxy resins, ester resins, etc. can be used. In particular, acrylic resins are preferable 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 the object of the present invention is not impaired. Examples of the 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, fillers, and the like.

Examples

[0028] Examples of the present invention will be described below, but various modifications and corrections are possible without departing from the technical scope of the present invention.

[0029] On one side of a spunbond non-woven fabric (40 g / m 2 ) of polyethylene terephthalate manufactured by the spunbond method, which is a known method for manufacturing non-woven fabrics, a second water-stop layer made of a laminate layer of low-density polyethylene (100 g / m 2 ) is formed by the T-die extrusion method. The surface of the second non-woven fabric layer opposite to the surface on which the second water-stop layer is formed, and a needle-punched non-woven fabric (70 g / m 2Between the first non-woven fabric layer consisting of 2 and a first water-stop layer made of a laminate layer of low-density polyethylene added with a weathering agent by a T-die extrusion method (30 g / m 2 , a roofing underlayment with a thickness of about 0.42 mm and a basis weight of 240 g / m

[0030] (1) Weight Table 1 below shows a comparison of the weight of the roofing underlayment of the example of the present invention obtained as described above and the weight of an asphalt-based roofing underlayment.

[0031]

Table 1

[0032] As shown in Table 1, the roofing underlayment of the present invention has only about 1 / 4 the weight of a general asphalt-based roofing underlayment, and it can be seen that it is very light. Therefore, it can be expected that the construction and work are simple and can be carried out safely. Furthermore, Table 2 below shows the physical property values of the roofing underlayment of the example of the present invention obtained as described above.

[0033]

Table 2

[0034] Since there are no standard values for the physical properties of resin-based roofing underlayments, the evaluation method for the physical properties in Table 2 is the "Standard No. ARK04 of the Japan Waterproofing Materials Association, Incorporated SIt complied with the provisions of "Modified Asphalt Roofing Underlayment Agent" of "-04". The evaluation methods for each physical property are described below. (1) Tensile Strength A test piece (length 200 mm, width 50 mm) was attached to a tensile testing machine so that the gripping interval was 100 mm, and it was pulled at a speed of 100 mm / min until the test piece broke, and the maximum load was obtained. However, during the test, if it broke within 10 mm from the gripping fixture, that test piece was excluded and a new test piece was added. The tensile strength (N / cm) was calculated by the following formula and expressed as the average value of 5 test pieces. T = P / W Here, T is the tensile strength (N / cm), P is the maximum load (N), and W is the width (cm) of the test piece. For the tensile strength after heat treatment, a test piece (length 200 mm, width 50 mm) was left standing on a wire mesh in a heating thermostat (JIS K6257) at 70°C ± 3°C for 168 hours, then taken out and cooled to room temperature, and then tested by the same method as above, and expressed as the average value of 5 test pieces.

[0035] (2) Heat Resistance A test piece (length 200 mm, width 200 mm) was suspended in a heating thermostat (JIS K6257) at 70°C ± 3°C for 2 hours, then taken out, and the presence or absence of peeling off of the coating, foaming, and bleeding of the resin that had penetrated was investigated.

[0036] (3) Tear Strength As shown in Figure 2, a cut 7 with a length of 75 mm was made parallel to the long side at the center of a test piece (length 100 mm, width 50 mm) 6 to create two tongues. Taking 45 mm from each end as the gripping margin, as shown in Figure 3, one side 6a of the test piece 6 was attached to a tensile testing machine 8 so that the gripping interval was 50 mm, the other side 6b of the test piece 6 was attached to the tensile testing machine 8, and it was pulled at a speed of 100 mm / min until the test piece 6 broke, and the maximum load was obtained. The tear strength (N) was expressed as the average value of 5 test pieces.

[0037] (4) Nail Hole Sealing Property As shown in Fig. 4, at 20°C, a test piece (90 mm in length and 90 mm in width) 10 was placed on a square waterproof plywood 9 (12 mm thick) with a vertical dimension of 100 mm and a horizontal dimension of 100 mm. A ring nail 11 (3.2 mm in diameter and 32 mm in length) was driven straight until the nail head was about 10 mm above the test piece 10, and this was used as the test body for the ring nail. A PVC pipe 12 with an inner diameter of 30 - 40 mm was set upright on the test body, and a seal 13 was applied around it. After the seal 13 hardened, a liquid 14 obtained by adding an appropriate amount of ink to water and stirring was poured into the PVC pipe 12 to a water head of 30 mm. After standing for 24 hours, the presence or absence of water leakage through the through nail 11 was checked. If no water leakage through the through nail 11 was observed, the above liquid was removed, and it was left standing for another 24 hours to check the condition of the base at the nail hole part. The case where no water leakage is observed means the case where the following 1) and 2) are satisfied. 1) The base is not wet in 8 or more of the 10 test bodies. 2) There is no water leakage through the through nail to the back surface of the base.

[0038] (5) Flexural resistance Using a steel round bar with a diameter of 20 mm and a length of 50 mm, and a low-temperature constant temperature bath (capable of adjusting the liquid or air temperature to the set temperature ±1°C) and a heating thermostat (capable of adjusting the temperature to 70°C ± 3°C), a test piece (250 mm in length and 25 mm in width) and the above round bar were left standing in the low-temperature constant temperature bath with the air temperature set at -10°C ± 1°C for 1 hour or more and then taken out. Immediately, the test piece was applied to the round bar and bent 180 degrees in 2 seconds, and it was examined whether cracks occurred on the surface of the test piece. The flexural resistance after heat treatment was determined by leaving a test piece (250 mm in length and 25 mm in width) standing on a wire mesh in a heating thermostat adjusted to 70°C ± 3°C for 168 hours. Then, the test piece was taken out of the heating thermostat and cooled to room temperature, and then left standing in the low-temperature constant temperature bath with the air temperature set at -5°C ± 1°C for 1 hour or more and then taken out. Immediately, the test piece was applied to the round bar and bent 180 degrees in 2 seconds, and it was examined whether cracks occurred on the surface of the test piece.

[0039] (6) Dimensional stability Using a heating thermostat (capable of adjusting the temperature to 60°C ± 3°C) and a constant temperature water bath (capable of adjusting the water temperature to 60°C ± 1°C), a test piece (300 mm in length and 50 mm in width) was horizontally placed still on a wire mesh in the heating thermostat adjusted to 60°C ± 3°C for 24 hours. Then, the test piece was taken out of the heating thermostat and cooled to room temperature, and immediately the length of the test piece was measured to 0.1 mm as the reference length. Next, the test piece was immersed in the constant temperature water bath adjusted to 60°C ± 1°C for 24 hours and then taken out, and the length of the test piece was measured to 0.1 mm to measure the difference (the first difference in length) from the reference length. Then, the test piece was horizontally placed still on the wire mesh in the heating thermostat adjusted to 60°C ± 3°C for 24 hours and then taken out, and the length of the test piece was measured to 0.1 mm to measure the difference (the second difference in length) from the reference length. This test was repeated 5 times, and the maximum value among the average value (mm) of the first difference in length and the average value (mm) of the second difference in length was taken as the dimensional stability (mm).

[0040] 《High strength》 As shown in Table 2, it can be seen that the roofing underlayment of the present invention has extremely high tensile strength and tear strength. On the other hand, when the current asphalt-based roofing underlayment is constructed during strong winds, there is a problem that it is easily blown by the wind and torn and flown away. Since the roofing underlayment of the present invention has extremely high tensile strength and tear strength, such problems do not occur even when constructed during strong winds.

[0041] 《Workability at high temperatures》 As shown in Table 2, it can be seen that the roofing underlayment of the present invention is excellent in heat resistance. On the other hand, when the current asphalt-based roofing underlayment is constructed at high temperatures such as in summer, it becomes soft and sticky, and there is a problem that shoes and work clothes are soiled. Since the roofing underlayment of the present invention is excellent in heat resistance, it does not become soft even at high temperatures and is not sticky, so shoes and work clothes are not soiled.

[0042] 《Workability at low temperatures》 As shown in Table 2, it can be seen from the test results of the flexural resistance that the roofing underlayment of the present invention does not cure even at low temperatures and does not crack even when bent. On the other hand, the current asphalt-based roofing underlayment has a problem that it becomes hard during construction at low temperatures such as in winter and cracks when bent. The roofing underlayment of the present invention does not cure even at low temperatures and does not crack even when bent.

[0043] 《Nail Hole Water Resistance》 As shown in Table 2, it can be seen from the test results of the nail hole sealing property that the roofing underlayment of the present invention has excellent nail hole water resistance.

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

[0045] 《Anti-Slip Property》 For the roofing underlayment used on the roof, anti-slip property is required for safety. Therefore, for the asphalt-based roofing underlayment and the roofing underlayment of the present invention, a slip test was conducted using the slip tester shown in Fig. 5 in accordance with JIS A1454:2016. In Fig. 5, 21 is a constant-speed motor, 22 is a speed reducer, 23 is a wire, 24 is a tensile speed adjuster, 25 is a tensile angle adjuster, 26 is a load converter, 27 is an initial load adjuster, 28 is a guide rail, 29 is a moving wheel, 30 is a weight, 31 is a steel slip piece pedestal, 32 is a slip piece, and 33 is a test piece. As a result, the coefficient of slip resistance (CSR) of the roofing underlayment of the present invention was 0.57 in the dry state and 0.53 in the wet state. On the other hand, the CSR of the asphalt-based roofing underlayment was 0.68 in the dry state and 0.63 in the wet state. A larger CSR value indicates greater slip resistance. Note that the dry state means the state where the surface of the test piece is wiped with a clean cloth, and the wet state means the state where a mixture of tap water, one type and seven types of test powders specified in JIS Z8901 in a mass ratio of 20:9:1 is sprayed on the surface of the test piece at a rate of 400 g / m 2 of the ratio.

[0046] On the other hand, in the Barrier-Free Act revised in August 2012, there is a description that "as an index of floor slipperiness, the coefficient of slip resistance (CSR) measured by the slipperiness test of floor materials defined in JIS A 1454 (Test Method for Polymer-Based Flooring Materials) is used." According to the new Barrier-Free Act, the recommended value of CSR for floors and road surfaces where people operate while wearing footwear is 0.4 or more. Therefore, it can be understood that the roofing underlayment of the present invention has excellent anti-slip properties.

[0047] Summarizing the above, it can be understood that the roofing underlayment of the present invention has the following advantages. It is lightweight and not slippery, so construction is easy. It has excellent workability at both high and low temperatures. It is not easily torn even when constructed under strong winds. Since the nail hole water-stopping property is good, there is no rain leakage from the construction part. The dimensional change is extremely small.

Description of Reference Numerals

[0048] 1 Roofing material 2 First non-woven fabric layer 3 First water-stopping layer 4 Second non-woven fabric layer 5 Second water-stopping layer

Claims

1. A roofing material comprising a first non-woven fabric layer made of a polyolefin synthetic fiber and / or a polyester synthetic fiber, a first water-stop layer made of a polyolefin synthetic resin provided under the first non-woven fabric layer, a second non-woven fabric layer made of a polyolefin synthetic fiber and / or a polyester synthetic fiber provided under the first water-stop layer, and a second water-stop layer made of a polyolefin synthetic resin provided under the second non-woven fabric layer, wherein the basis weight of the non-woven fabric constituting the first non-woven fabric layer is in the range of 65 to 100 g / m ２ and the basis weight of the non-woven fabric constituting the second non-woven fabric layer is in the range of 30 to 100 g / m ２ and the basis weight of the polyolefin synthetic resin constituting the first water-stop layer is in the range of 25 to 50 g / m ２ and the basis weight of the polyolefin synthetic resin constituting the second water-stop layer is in the range of 70 to 200 g / m ２ The roofing underlayment material is characterized in that it is in the above ranges.

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

3. The roofing underlayment material according to claim 1 or 2, wherein the non-woven fabric of the first non-woven fabric layer is a needle-punched non-woven fabric made of polypropylene, and the non-woven fabric of the second non-woven fabric layer is a spunbond non-woven fabric made of polyethylene terephthalate.

4. The roofing underlayment material according to claim 3, wherein the tensile strength of the non-woven fabric constituting the first non-woven fabric layer is 140 N / cm or more in the length direction, 80 N / cm or more in the width direction, the tear strength is 15 N or more in the length direction, 20 N or more in the width direction, the tensile strength of the non-woven fabric constituting the second non-woven fabric layer is 100 N / cm or more in the length direction, 40 N / cm or more in the width direction, and the tear strength is 5 N or more in the length direction and 5 N or more in the width direction.

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