JP3070218B2 - Tough, breathable and waterproof sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-permeable and waterproof sheet having a firm stiffness.

More specifically, the method is mainly used as a house wrap material or a roof base sheet material used for functions such as moisture permeability, waterproofness and heat insulation in the ventilation method of an outer wall of a wooden house, or for growing crops and plants. The present invention relates to a stiff, moisture-permeable and waterproof sheet that can be used in the fields of assisting agricultural and horticultural sheet materials.

[0003]

2. Description of the Related Art Conventionally, when building a wooden house or the like, a method of filling a heat insulating material between an interior material and an outer wall has been generally used for the purpose of shutting off outside air and keeping the indoor heat. I have.

[0004] However, in this case, water vapor generated in the room is cooled between the interior material and the outer wall, and water droplets formed by condensation cause the interior material and members including the heat insulating material to corrode, and also cause propagation of various bacteria and pests. There is an adverse effect such as promoting corrosion by promoting it and shortening the life of the building, and is particularly remarkable in a cold region or the like.

In recent years, in order to improve these problems, FIG.
As shown in (1), a construction method generally called an outer wall ventilation construction method has been developed and implemented.

That is, in FIG. 1, the ventilation layer 2 is provided between the outside of the heat insulating material layer 4 and the outer wall 1. In this case, the heat insulating material 4 such as glass wool has a large air permeability, and the cool air in the gas permeable layer enters the heat insulating material to significantly reduce the heat insulating effect. Therefore, the house wrap 3 may be provided to prevent this. Generally done. Inside the heat insulating material 4 such as glass wool, a moisture proof material 5 such as a polyethylene film and an interior material 6 are provided.

[0007] The functional characteristics required of such a house wrap 3 are as follows: water vapor generated in the room passes through the ventilation layer 2 and escapes to the outside;
Prevent intrusion into the side, and prevent water droplets from penetrating into the heat insulating material layer 4 (particularly during construction work where the outer wall is not stretched, this windproof material is the outermost, so this function is also important). It is desired that the workability is good and the cost is low.

Conventionally, as such a house wrap,
Asphalt impregnated felts have been used.

Further, a polyethylene nonwoven fabric obtained by a flash spinning method has been put on the market.
JP-A-223249 proposes to use a laminate of a stretched polyolefin film and a polyolefin tape fabric at the site. In addition,
Japanese Patent No. 65873 proposes to use a sheet obtained by subjecting a non-woven sheet using a core-sheath fiber in which a resin having a low melting point and high hydrophobicity is disposed in a sheath component to calendering treatment.

However, asphalt-impregnated felt has a low moisture permeability (264 g / m ² · 24 hours in one example data), so the above-mentioned problem occurs, and the problem cannot be solved by the outer wall ventilation method. Was. Furthermore, since the weight per unit area is large and heavy (420 g / m ² ), it is inconvenient to carry. In addition, when the nails are hit with a nail on a crossbar or the like because the back side is not visible at all, the workability is inferior, such as damage to the struts. There was a defect.

Although the above-mentioned polyethylene nonwoven fabric has no major disadvantages in properties, it is opaque and the back side is not visible at all, so that workability at a target position is poor, and the production method is difficult and the cost is high. There was also. Further, the method proposed in Japanese Patent Application Laid-Open No. 63-223249 has problems in that the balance between moisture permeability and air permeability is difficult, and that the production method is difficult. In addition,
According to the method proposed in Japanese Patent No. 65873, a high moisture permeability is inferior in water resistance and air permeability, and a high water resistance is inferior in moisture permeability. No flexible sheet material was obtained.

In recent years, a bonding adhesive sheet of a melt-blown nonwoven fabric and a spun-bonded nonwoven fabric has been proposed, and although it is excellent in function, there is a problem that the feel is too soft and hangs down at the time of on-site construction, making it difficult to construct.

In addition, non-woven fabrics and woven or knitted products on the market which are processed with resin have low moisture resistance and poor waterproofness if they have good moisture permeability, and have poor windproofness due to too good air permeability. Currently, no well-balanced house wrap has been obtained.

[0014]

DISCLOSURE OF THE INVENTION The present inventors have sufficiently considered the above problems and have no such problems.
With practical properties such as tensile strength, moisture permeability, waterproof,
Extensive study of house wraps that are excellent in workability, such as easy to strike with nails, etc. because they are excellent in functional characteristics such as windproofness and have appropriate hardness considering workability, and can be manufactured at low cost And finally arrived at the present invention.

[0015]

The stretchable, moisture-permeable and waterproof sheet of the present invention which achieves the above object has an average fiber diameter of constituent fibers of 5 μm or less, a basis weight of 15 g / m ² or more, and an apparent fiber appearance. A melt-blown ultra-fine fiber non-woven fabric (A) having a density of 0.40 g / cm ³ or less, and a long-fiber non-woven fabric (B) having an average fiber diameter of 10 μm or more and a basis weight of 20 g / m ² or more of a non-woven fabric (A) and a non-woven fabric (B) and a laminated non-woven fabric which is bonded and integrated by partial hot-melt bonding. In the surface layer from the surface of the non-woven fabric (B) side to a depth of 40 μm, the fiber filling rate is at least 60%. And a stretchable moisture-permeable and waterproof sheet characterized by being fused at least partially between fibers.

In the stretchable moisture-permeable and waterproof sheet of the present invention, the laminated nonwoven fabric preferably has a moisture permeability of at least 4000 (g / m ² · 24 hours) and a water resistance of at least 600 (mm water column). It is characterized by having.

Alternatively and preferably, the constituent fiber components of the nonwoven fabric (A) and / or the nonwoven fabric (B) are preferably
It is a polyolefin resin or a copolymer thereof.

Alternatively, the constituent fiber component of the nonwoven fabric (A) and / or the nonwoven fabric (B) is a polypropylene resin or a copolymer thereof.

Alternatively, the non-woven fabric (B) is characterized in that the constituent fibers are core-sheath type composite fibers having a fiber-forming component as a core component and an adhesive component as a sheath component. Alternatively or additionally, at least the constituent fibers of the nonwoven fabric (A) and / or the constituent fibers of the nonwoven fabric (B) contain an ultraviolet absorbent.

Alternatively, it is characterized in that it is further subjected to a water repellent treatment.

[0021] Alternatively, the present invention is a house wrap material using a moisture-permeable and waterproof sheet having tension.

Alternatively, the present invention is an agricultural / horticultural sheet using a stiff, moisture-permeable / waterproof sheet.

[0023]

The following is a more detailed description of the stretchable, moisture-permeable and waterproof sheet of the present invention.

First, in the present invention, as a method for measuring the above-mentioned fiber filling rate, as shown in FIGS.
The cross section of the surface portion of the long-fiber nonwoven fabric (B) from the surface to the depth of 40 μm in the area excluding the hot-melt bonding portion was photographed with a 500 × cross section using a scanning electron microscope.
The 00 micron width (200 micron width × 10 places) was binarized using an image processing apparatus to sharpen the fiber portion and the void portion, and the fiber occupying area ratio was calculated as the fiber filling ratio. It is assumed that. In the present invention, the measurement points are randomly sampled, and the average value is obtained by setting n to 10.

FIGS. 2A and 2B are exploded views showing a method of measuring the fiber filling rate. FIG. 2A is a 500-fold run-difference-type electron of the long-fiber nonwoven fabric (B) side. FIG. 2 (b) is a copy view of one example of a microscope cross-sectional photograph, and FIG. 2 (b) shows one example of binarization processing from the surface of a to a depth of 40 microns using an image processing apparatus. .

First, the moisture permeability, waterproofness, and windproofness are largely influenced mainly by factors such as the void area, the void number density, the thickness, and the contact angle with water between the fibers constituting the sheet. Of these factors, the void area between fibers, the contact angle with water is reduced, the water resistance is improved, the void area between fibers, the density of voids is reduced, and the air permeability is reduced by increasing the thickness. On the contrary, it is important to balance these basic factors well, because the void area, the void number density is large, the moisture permeability is large if the thickness is small, etc. It is greatly related to the size.

That is, with respect to functional properties such as moisture permeability, waterproofness, and windproofness, it is important to use a melt blown ultrafine fiber nonwoven fabric having an average fiber diameter of 5 μm or less and a basis weight of 15 g / m ² or more. Average fiber diameter is 5
When the size is larger than micron or the basis weight is 15 g / m ²
If it is smaller than the above range, desired properties such as moisture permeability, waterproofness, windproofness, and the like, which are the objectives of the present invention, cannot be obtained. Even if such a melt-blown ultrafine fiber nonwoven fabric is used, it is particularly preferable that the thickness is 4 μm or less, since the moisture permeability is hardly impaired and the water resistance is high and the waterproofness is excellent. In this case, it is preferable because the air permeability is reduced and the wind resistance is improved. Further, when the average fiber diameter is 3 μm or less, it is more preferably used because the waterproof property and the windproof property are improved while maintaining practical moisture permeability. Such a melt blown ultrafine fiber nonwoven fabric, if the basis weight is too small, is excellent in moisture permeability, but is poor in waterproofness due to low water resistance, and also results in poor windproofness due to too large air permeability, so the intended purpose As the basis for achieving
It is important that it is 5 g / m ² or more. In particular, 20g
/ M ² is more preferable because the above functional characteristics can be stably obtained. On the other hand, the upper limit of the basis weight is not particularly limited, but if it is too large, the waterproofness and windproofness are excellent, but the moisture permeability gradually decreases, and the weight becomes heavy, so the workability is inferior, and the cost becomes high. Therefore, those having a basis weight as small as possible are preferable, and those having a basis weight of 200 g / m ² or less are preferably used in consideration of the fact that the functional characteristics can be stably obtained.

The melt blown ultrafine fibrous nonwoven fabric used in the present invention is produced by a process in which a heating high-speed gas is blown against a fine stream of a molten polymer and the molten polymer is stretched by the action of the gas flow to produce an ultrafine nonwoven fabric. Any method may be used as long as it is formed by a melt blow method that forms fibers and collects them into sheets, and details thereof are not particularly limited.

The resin forming the constituent fibers of the melt-blown ultrafine fiber nonwoven fabric used in the present invention includes polyolefins such as polypropylene and polyethylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon 6 and nylon 66; There are copolymers, polyvinyl chloride, acrylic and acrylic copolymers, polystyrene, polysulfone, polytrifluorochloroethylene, polycarbonate, polyurethane and the like. Among these, although not particularly limited, polyolefins such as polypropylene and polyethylene are preferred from the viewpoint of spinnability and water repellency, especially since the contact angle with water is small, and particularly polypropylene is preferred from the viewpoint of ease of melt blow spinning. .

The stretchable moisture-permeable / waterproof sheet of the present invention may vary depending on the purpose, but it is necessary to have physical properties such as tensile strength and appropriate hardness from a practical aspect such as workability. However, the melt-blown non-woven fabric alone has low strength properties, is thin and flexible due to the thinness of the fiber, and cannot generally achieve appropriate hardness. Therefore, the average fiber diameter of the constituent fibers relative to the melt-blown non-woven fabric (A) It is important that the long-fiber nonwoven fabric (B) having a thickness of 10 μm or more and a basis weight of 20 g / m ² or more be partially hot-melt bonded to obtain a laminated and integrated sheet and obtain practical physical properties. Here, the term “thermal fusion bonding” refers to bonding by thermal action, and refers to bonding such as thermal fusion, softening bonding, and soft bonding.

The nonwoven fabric (B) has an average fiber diameter of 1
If it is 0 μm or more, if it is less than 100 μm, and if the basis weight is less than 20 g / m ² , it is difficult to impart the above-mentioned strength properties, appropriate hardness, and the like. The non-woven fabric (B) is cut into filaments made of ordinary fibers into short fibers, and the temperature of the non-woven fabric is reduced to a temperature at which the non-woven fabric obtained through web forming, needle punching, or the like, or a fiber formed by a basic process from a nozzle can be formed. The molten polymer may be drawn by suction with a high-speed suction gas, then spread using a fiber opening device, and may be a nonwoven fabric obtained by a spunbond method of forming a sheet by colliding and collecting a sheet in a conveyor-like net,
Although not particularly limited, a nonwoven fabric formed by a spun bond method is preferable because stable strong properties are easily obtained, the manufacturing method is simple, and the manufacturing cost is low.
The spunbonded nonwoven fabric may be a core-sheath composite fiber having a fiber-forming component as a core component and an adhesive component as a sheath component. As the resin forming the constituent fibers of the nonwoven fabric by the spunbond method, polyethylene, polyolefins such as polypropylene, polyethylene terephthalate, polyesters such as polybutylene terephthalate,
Examples include polyamides such as nylon 6 and nylon 66 or copolymers thereof, polyvinyl chloride, acrylic or acrylic copolymers, polystyrene, polysulfone, polytrifluorochloroethylene, polycarbonate, and polyurethane. In the present invention, although not particularly limited, polyolefins such as polypropylene and polyethylene are preferred from the viewpoint of spinning stability, water repellency, low cost, and the like. Polypropylene is particularly preferred from the viewpoint of ease, and also in the case of a core-sheath composite fiber, the above resin is used for the heat-adhesive component (sheath), and the fiber-forming component (core)
Preferred examples thereof include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and copolymers thereof.

In the present invention, the nonwoven fabrics (A) and (B)
Is bonded and integrated by partial hot-melt bonding. However, since it is bonded and integrated by such partial hot-melt bonding, the moisture permeability mainly achieved by the nonwoven fabric (A) is Functional properties such as waterproofness and windproofness can be well maintained as a laminated sheet.

As a method for obtaining a moisture-permeable / waterproof sheet bonded and bonded and integrated by partial heat fusion, various methods can be adopted and are not particularly limited. By simply laminating a previously prepared nonwoven fabric (A) and another previously prepared nonwoven fabric (B), or by spraying a melt-blown ultrafine fiber onto the previously prepared nonwoven fabric (B) to form a nonwoven fabric (A). Lamination, furthermore, the obtained laminate may be partially thermally bonded, and may be obtained by any means such as hot embossing, ultrasonic wave or high frequency wave, but is not particularly limited, but cost advantage. From the standpoint of practicality and the like, a hot embossing method having an uneven pattern is preferably used.

In the heat bonding process, it is important to take care not to make the heat bonded portion extremely thin or to make a hole during the processing.

Here, in the stretchable moisture-permeable / waterproof sheet of the present invention, an appropriate hardness for improving the workability is obtained in the surface layer from the surface of the nonwoven fabric (B) to a depth of 40 μm. Has a fiber filling rate of at least 60%, and
This can be achieved by at least partially inter-fiber fusion. It is important that the fiber filling rate is at least 60%, and when the fiber filling rate exceeds 80%, the film formation of the fiber proceeds, and the fiber filling rate becomes more preferable. In addition, "the fiber filling rate is at least 6 in the surface layer portion from the surface of the nonwoven fabric (B) side to a depth of 40 microns.
“0%” means that the nonwoven fabric (B) has a thickness of 40 μm or less (although it is generally rare) that the fiber filling rate of the entire nonwoven fabric (B) is at least 60% ” It means that.

The laminated nonwoven fabric has a moisture permeability of at least 400
0 (g / m ² · 24 hours), water resistance is at least 600
(Mm water column) is preferable because the moisture permeation / waterproof effect can be favorably exhibited.

The method for obtaining the stiff and moisture-permeable / waterproof sheet of the present invention is not particularly limited as long as it can be configured so as to satisfy the above-mentioned physical characteristics. For example, a nonwoven fabric of a laminated nonwoven fabric (B)
Non-woven fabric (B) and non-woven fabric (A) hot-pressed so that only the surface on the side is heated, or non-woven fabric (A) previously hot-pressed so that only the surface is heated, is integrated by partial heat-fusion Can be achieved. At this time, processing conditions such as a roll temperature, a pressing pressure, a processing speed, and a processing clearance are not particularly limited as long as the above requirements are satisfied. Here, as long as the above requirements are satisfied, hot pressing may be performed so that the surface on the nonwoven fabric (A) side is heated, but if the roll temperature is high, the water resistance may be poor.

In the present invention, at least the nonwoven fabric (A)
It is preferable to include an ultraviolet absorber in the constituent fibers of (1) and / or the constituent fibers of the non-woven fabric (B) since the durability, particularly the light resistance, can be stably obtained. Further, the amount of the ultraviolet absorber added varies depending on the type of the ultraviolet absorber and the degree of improvement in light resistance, and may be appropriately added as long as the effects of the present invention are not impaired.
In addition, addition of an antioxidant such as a radical chain inhibitor or a peroxide decomposer in combination with an ultraviolet absorber is also a means that can be appropriately taken as desired.

Further, if the sheet of the present invention is treated with a water repellent, it can be used positively because the water resistance can be efficiently improved.

[0040]

As described above, according to the present invention, it has practical properties such as tensile strength, excellent functional properties such as moisture permeability, waterproofness and windproofness, and also has appropriate hardness. When used as a dew-prevention windproof sheet for home construction, the sheet has good functional properties, such as moisture permeability, waterproofness, and windproofness. In addition to preventing rainwater intrusion, it has a great effect of providing a comfortable feeling of living, such as being excellent in heat retention and dew condensation prevention after moving in, as well as greatly improving the useful life of the building.

Further, since the back surface of the sheet can be seen through, there is no failure such as hitting with a nail on a crosspiece or the like, and the sheet is about 5 to 6 times thicker than conventionally used asphalt-impregnated felt or paper. Because it is twice as light, the workability at the time of carrying and construction is remarkably improved, so that it is possible to provide a building material sheet suitable as a dew-prevention windproof sheet in the outer wall ventilation method.

Further, since it is excellent in air permeability and moisture permeability, it can be used for agricultural materials. For example, if it is used as a lining curtain of a greenhouse, it can exhibit the effect of preventing dew condensation at night and preventing crop diseases caused by falling water drops.

The stretchable moisture-permeable / waterproof sheet of the present invention can be used for various filters, wipers, wrapping materials, disposable diapers, sanitary products, etc. due to the excellent features of the melt-blown ultrafine fiber nonwoven fabric constituting the sheet. It can be applied to a wide range of uses such as coating sheets and medical uses.

[0044]

The following examples are provided to further clarify the present invention, and the present invention is not limited thereto.

Each physical property in the examples was measured by the following methods.

(1) Moisture permeability: JIS-Z-0208 (40
(° C-90% RH) (2) Water resistance: JIS-L-1092A method (3) Air permeability: JIS-L-1096 (Fragile method) (4) Tensile strength: JIS-L-1096 (5) Bending resistance : JIS-L-1079 (45 ° cantilever method, measured value with nonwoven fabric (B) side as the surface) (6) Average fiber diameter: 300 or more from an enlarged photograph of 1000 times (scanning electron microscope) The fiber diameter was read and the average value was taken.

Comparative Examples 1 and 2 Melt flow index (load: 2.16 kg, 230
° C) 60 g / 10 min polypropylene (melting point 157.6)
C.) to obtain a melt-blown ultrafine fiber nonwoven fabric (A) having an average fiber diameter of 1.5 μm and a basis weight of 30 g / m ² by a melt blow spinning method.

Then, the non-woven fabric (A) is put on the upper layer, and the basis weight is 30 g.
/ M ² (Comparative Example 1) and 50 g / m ² (Comparative Example 2) of polypropylene spunbonded nonwoven fabric (B) (product of Nippon Nonwovens Co., Ltd., average fiber diameter of 27 μm) as a lower layer. While holding it between the uneven rolls (upper roll) at 140 ° C and the plain rolls (lower roll) at 140 ° C,
A heat bonding sheet was obtained at a pressure of 80 kg / cm. In addition, Table 1 shows the measurement results of the fiber sufficiency in the surface layer portion from the surface of the nonwoven fabric (B) side of these sheets to a depth of 40 μm.
Table 2 shows other processing results.

[0049]

[Table 1]

[Table 2] Examples 1 and 2 The nonwoven fabric (B) side of the heat bonding sheet obtained in Comparative Examples 1 and 2 was 1
A 25 ° C iron plain roll (upper roll), while holding the non-woven fabric (A) side as a normal temperature rubber roll,
Nip pressure is 30kg / cm, clearance is 0m
m, and the roll speed was 5 m / min. Most of the surface layer on the nonwoven fabric (B) side of this sheet had inter-fiber fusion. Table 1 shows the measurement results of the fiber sufficiency in the surface layer portion having a depth of 40 μm from the surface of the nonwoven fabric (B) side of these sheets, and Table 2 shows other processing results.

Example 3 The non-woven fabric (A) side of the heat bonding sheet obtained in Comparative Example 1 was 125
℃ iron plain roll (upper roll), non-woven fabric (B)
Processing was performed under the conditions of a nip pressure of 30 Kg / cm, a clearance of 0 mm, and a roll speed of 5 m / min while holding the rubber roll at a normal temperature. In the majority of the surface layer on the nonwoven fabric (A) side of this sheet, the fibers were fused. Table 2 shows the processing results.

As can be seen from Tables 1 and 2, the product of the present invention (Examples 1, 2, and 3) has a fiber filling ratio in the surface layer portion from the surface of the nonwoven fabric (B) side to a depth of 40 μm which is a comparative example. It is much higher than the first and second products, and has a moderate rigidity as indicated by the value of rigidity, so there is no form instability at the time of construction, moisture permeability, water resistance, wind resistance etc. Was excellent and was excellent as a stiff, moisture-permeable and waterproof sheet. In the case of Example 3, the water resistance was as small as 510 (water column) and the rigidity was inferior to those of Examples 1 and 2, but in terms of moisture permeability, it was satisfactory as a whole. .

Example 4 A fluorinated water repellent ("Fine Guard", manufactured by Sanwa Kasei Co., Ltd.) was applied to the sheet prepared in Example 1, and the sheet was treated with hot air at 80 ° C. for 10 minutes to reduce the water repellency. As a result of the evaluation, 90 points before the processing were improved to 100 points after the processing. The water resistance was also changed from a 1200 mm water column before the treatment to 1350 after the treatment.
mm water column, and was excellent as a stiff, moisture-permeable and waterproof sheet.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a general outer wall ventilation method.

FIGS. 2 (a) and 2 (b) are exploded views showing a method of measuring a fiber filling rate, and FIG. 2 (a) is a 500-fold run-difference type electron on the long fiber nonwoven fabric (B) side. FIG. 2 (b) is a copy view of one example of a microscope cross-sectional photograph, and FIG. 2 (b) shows one example of binarizing the surface from (a) to a depth of 40 microns using an image processing apparatus. It is.

[Explanation of symbols]

 1: outer wall material 2: ventilation layer 3: windproof material according to the present invention 4: heat insulating material (glass wool or the like) 5: moistureproof material (polyethylene film or the like) 6: interior material

Claims (9)

(57) [Claims] An average fiber diameter of the constituent fibers is 5 μm or less, a basis weight is 15 g / m ² or more, and an apparent density of the fibers is 0.40 g / c.
melt blown ultrafine fiber non-woven fabric (A) of not more than ³ m, average fiber diameter of constituent fibers of not less than 10 μm, and basis weight of 20 g / m ²
The long-fiber non-woven fabric (B) is a laminated non-woven fabric obtained by bonding and integrating the non-woven fabric (A) and the non-woven fabric (B) by partial hot-melt bonding. A stiff, moisture-permeable and waterproof sheet characterized by having a fiber filling rate of at least 60% in a surface layer portion having a thickness of up to 40 microns and being at least partially fused between fibers. 2. The laminated nonwoven fabric has a moisture permeability of at least 4000.
(G / m ² · 24 hours), water resistance is at least 600
2. The stretchable, moisture-permeable and waterproof sheet according to claim 1, wherein the sheet is (mm water column). 3. Nonwoven fabric (A) and / or nonwoven fabric (B)
3. The stretchable moisture-permeable and waterproof sheet according to claim 1, wherein the constituent fiber component is a polyolefin resin or a copolymer thereof. 4. Nonwoven fabric (A) and / or nonwoven fabric (B)
4. The stretchable moisture-permeable and waterproof sheet according to claim 1, wherein the constituent fiber component is a polypropylene resin or a copolymer thereof. 5. The nonwoven fabric (B) according to claim 1, wherein the constituent fibers are core-sheath composite fibers having a fiber-forming component as a core component and an adhesive component as a sheath component. A permeable, waterproof sheet with a firm stretch as described. 6. The non-woven fabric (A) and / or the non-woven fabric (B) comprises at least a constituent fiber containing an ultraviolet absorbent. A breathable and waterproof sheet with a tight waist. 7. The stretchable, moisture-permeable and waterproof sheet according to claim 1, wherein the sheet has been subjected to a water-repellent treatment. 8. A house wrap material using the stretchable, moisture-permeable and waterproof sheet according to claim 1, 2, 3, 4, 5, 6, or 7. 9. An agricultural and horticultural sheet using the stretchable, moisture-permeable and waterproof sheet according to claim 1, 2, 3, 4, 5, 6, or 7.