JP6997563B2 - Breathable waterproof sheet and clothing fabric - Google Patents

Description

The present invention relates to a moisture permeable waterproof sheet and a clothing fabric using the same.

Patent Document 1 discloses that a moisture-permeable waterproof sheet having a waterproof function and a moisture permeability is used as a building material.

Japanese Unexamined Patent Publication No. 2011-93294 (paragraphs [0008] to [0011])

In recent years, in order to use the moisture permeable waterproof sheet for, for example, clothing fabrics, it is required to give the moisture permeable waterproof sheet excellent heat insulating performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a moisture-permeable waterproof sheet having excellent heat insulating performance and a clothing fabric using the same.

As a result of diligent studies to solve the above problems, the inventor of the present application uses an open-cell foamed sheet having fine bubbles as a moisture-permeable waterproof sheet to ensure excellent heat insulation performance while ensuring moisture permeability and waterproofness. I got the finding that I can have it. Then, based on this finding, the following invention was completed.

That is, in the first aspect of the invention, the open cell foam sheet having a bubble diameter of 100 μm or less and a foaming ratio of 10 to 30 times and a reinforcing sheet having a continuous porous structure are laminated and provided, and the open cell foam sheet is provided. A moisture-permeable waterproof sheet in which the bubbles of the open-cell foamed sheet and the holes of the reinforcing sheet communicate with each other at the boundary portion between the reinforcing sheet and the reinforcing sheet.

A second aspect of the invention is the moisture-permeable waterproof sheet according to the first aspect , wherein the open-cell foaming sheet is obtained by foaming a fluid in a supercritical state as a foaming agent.

A third aspect of the invention is the moisture-permeable waterproof sheet according to the first aspect or the second aspect , wherein the reinforcing sheet is made of an olefin-based long fiber non-woven fabric.

A fourth aspect of the invention is the moisture-permeable waterproof sheet according to the third aspect , wherein the reinforcing sheet is made of a non-woven fabric made of fibers having a core-sheath structure.

A fifth aspect of the invention is described in any one of the first to fourth aspects , wherein the open cell foam sheet and the reinforcing sheet are bonded by hot melt adhesives scattered at a plurality of locations. It is a breathable waterproof sheet.

A sixth aspect of the invention is any one of the first to fifth aspects , wherein a breathable lining material is laminated on the surface of the open-cell foamed sheet facing the opposite side to the reinforcing sheet. It is a moisture-permeable waterproof sheet described in 1.

A seventh aspect of the invention is a clothing fabric using the moisture permeable waterproof sheet according to any one of the first to sixth aspects .

Since the moisture-permeable waterproof sheet and the clothing fabric according to the present invention include an open-cell foamed sheet having heat insulating performance as a component, it is possible to exhibit excellent heat insulating performance. Further, since the moisture permeable waterproof sheet is formed by laminating a reinforcing sheet on the open cell foamed sheet, the strength of the moisture permeable waterproof sheet can be improved. Moreover, in the moisture permeable waterproof sheet of the present invention, the reinforcing sheet has a continuous porous structure, and the bubble diameter of the open cell foamed sheet is 100 μm or less. Further, since the bubbles of the open cell foam sheet and the holes of the reinforcing sheet communicate with each other at the boundary portion between the open cell foam sheet and the reinforcing sheet, it is possible to increase the strength without impairing the moisture permeability and waterproofness. ..

Here, if the open cell foam sheet is formed by foaming a supercritical fluid as a foaming agent, it becomes easy to uniformly form fine open cells of 100 μm or less ( second aspect of the invention ).

The reinforcing sheet may be a non-woven fabric, a woven fabric, a knitted fabric, or a microporous film. In particular, if the reinforcing sheet is made of an olefin fiber non-woven fabric, it can be bonded to the open cell foamed sheet only by heating without using an adhesive. Moreover, when the olefin-based fiber nonwoven fabric is a long-fiber nonwoven fabric, the physical strength of the reinforcing sheet is improved, and the durability of the moisture-permeable waterproof sheet is improved ( the third aspect of the invention ). Further, the reinforcing sheet is preferably composed of a non-woven fabric made of fibers having a core-sheath structure ( fourth aspect of the invention ). By using a non-woven fabric having a core-sheath structure, it is possible to stack the reinforcing sheet with the open cell foam sheet at a low melting point while ensuring the physical strength of the reinforcing sheet.

The open cell foam sheet and the reinforcing sheet may be bonded by a hot melt adhesive. In this case, the hot melt adhesive is preferably scattered at a plurality of locations in order to ensure the moisture permeability and breathability of the moisture permeable waterproof sheet ( the fifth aspect of the invention ).

Further, a breathable lining material may be laminated on the surface of the open cell foam sheet facing the opposite side to the reinforcing sheet. With such a configuration, it becomes easy to use the moisture permeable waterproof sheet for clothing fabrics.

(A) Cross-sectional view of the moisture-permeable waterproof sheet, (B) Cross-sectional view showing another example of the moisture-permeable waterproof sheet. Cross-sectional view schematically showing the boundary between the open cell foam sheet and the reinforcing sheet Table showing the experimental results of Experimental Examples A1 to A7 A table showing the experimental results of Experimental Examples A4 and B1 to B3.

As shown in FIG. 1A, the moisture-permeable waterproof sheet 10 of the present embodiment includes the open cell foamed sheet 11 and the reinforcing sheet 21 in a laminated manner. The moisture permeable waterproof sheet 10 may be used as a waterproof sheet for building materials or precision machinery, or may be used as a cloth for clothing.

The open cell foaming sheet 11 is formed by foaming carbon dioxide or nitrogen in a supercritical state as a foaming agent. This facilitates the uniform formation of fine open cells of 100 μm or less in the open cell foamed sheet 11. Specifically, the bubble diameter of the open cell foamed sheet 11 is 50 to 100 μm, and the foaming ratio of the open cell foamed sheet 11 is 10 to 30 times.

As shown in FIG. 2, there is no skin layer on the outer surface of the open cell foamed sheet 11, and the bubbles 12 are exposed. Such an open cell foam sheet 11 can be easily obtained by cutting off the skin layer formed on the outer surface of the sheet-shaped molded body in the process of foam molding. The thickness of the open cell foam sheet 11 after the skin layer has been removed is 0.8 to 1.2 mm.

The resin constituting the open cell foamed sheet 11 may be a polyolefin-based resin, or may be a resin composition containing a polyolefin-based resin and a thermoplastic elastomer or rubber. In the latter case, in order to obtain a high foam, the amount of the polyolefin resin is preferably 50 to 95% by weight, and the amount of the thermoplastic elastomer or rubber is preferably 5 to 50% by weight. If the proportion of the thermoplastic elastomer or rubber is less than 5% by weight, it becomes difficult to give the open cell foamed sheet 11 sufficient flexibility. Further, if the proportion of the thermoplastic elastomer or rubber exceeds 50% by weight, there arises a problem that the shrinkage of the open cell foamed sheet 11 becomes large.

Examples of the polyolefin resin include polyethylene, polypropylene, an ethylene-propylene copolymer, and an ethylene-α-olefin copolymer. Here, the copolymer may be a random copolymer or a block copolymer. Examples of α-olefins include olefins such as propylene, 1-butene, 1-pentene and 1-hexene, diene such as butadiene, 1,5-hexadiene and 1,4-hexadiene, and cyclopentene. Cyclic olefins such as cyclopentadiene can be mentioned.

The polyethylene may be any of high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, low-density polyethylene and the like.

Polypropylene may be any of atactic, isotactic, and syndiotactic depending on the type of crystal structure. Further, polypropylene may be a homopolymer (homopolymer) or a copolymer (copolymer) depending on the type of polymerization. The polypropylene copolymer may be either a block type or a random type. Ethylene is generally used as the copolymerization monomer in the polypropylene copolymer, but is not limited thereto.

Examples of the thermoplastic elastomer include olefin-based elastomers and styrene-based thermoplastic elastomers. Examples of the olefin-based elastomer include ethylene-propylene rubber represented by EPR which is a copolymer of ethylene and propylene and EPDM which is a copolymer of ethylene, propylene and a small amount of non-conjugated diene. Further, as another example of the olefin-based elastomer, a copolymer of ethylene and α-olefin using a metallocene catalyst (for example, ethylene-1-butene rubber, ethylene-1-octene rubber) can be mentioned. Examples of the styrene-based thermoplastic elastomer include block copolymers in which polystyrene is bonded to one end or both ends of a polymer composed of hydrocarbon chains. Examples of such block copolymers include block copolymers of styrene and butadiene, isoprene, isoprene, etc., or those obtained by further hydrogenating these block copolymers, and even when used alone, two or more types are mixed. May be used.

The reinforcing sheet 21 has a continuous porous structure. Then, as shown in FIG. 2, in the moisture permeable waterproof sheet 10, the bubbles 12 of the open cell foam sheet 11 and the holes 24 of the reinforcing sheet 21 communicate with each other at the boundary portion between the open cell foam sheet 11 and the reinforcing sheet 21. ing. As a result, the moisture permeability and breathability of the moisture permeable waterproof sheet 10 are ensured. The reinforcing sheet 21 is not particularly limited as long as it has a continuously porous structure, but in order for the moisture permeable waterproof sheet 10 to have waterproofness, the diameter of the holes 24 of the reinforcing sheet 21 must be smaller than the maximum diameter of raindrops. (Specifically, it is 2000 μm or less), more preferably smaller than the maximum diameter of drizzle (specifically, 500 μm or less), and further preferably 100 μm or less.

Adhesion of the reinforcing sheet 21 to the open cell foamed sheet 11 may be performed by a thermal laminating or a dielectric heating laminating, or may be performed by a hot melt adhesive. When the reinforcing sheet 21 is adhered by the hot melt adhesive, the hot melt adhesive is scattered at the boundary portion between the open cell foamed sheet 11 and the reinforcing sheet 21 in order to maintain the moisture permeability of the moisture permeable waterproof sheet 10. It is preferable to do so.

Specifically, the reinforcing sheet 21 is made of a non-woven fabric. From the viewpoint of the strength of the reinforcing sheet 21, the nonwoven fabric is preferably a long fiber nonwoven fabric. Further, as shown in FIG. 2, the fiber constituting the nonwoven fabric preferably has a core-sheath structure in which the outside of the core portion 22 having a continuous porous structure is covered with a sheath portion 23 having a melting point lower than that of the core portion 22. .. When the fibers of the non-woven fabric have a core-sheath structure, it becomes easy to maintain the continuous porous structure of the reinforcing sheet 21 when the reinforcing sheet 21 is adhered to the open cell foamed sheet 11 by the above-mentioned thermal laminating or dielectric heating laminating.

Examples of the non-woven fabric constituting the reinforcing sheet 21 include an olefin-based fiber non-woven fabric, a polyester-based fiber non-woven fabric, and a nylon-based fiber non-woven fabric. Examples of the polyolefin constituting the polyolefin-based fiber nonwoven fabric include polyethylene, polypropylene, and polybutylene. Examples of the polyester constituting the polyester-based fiber nonwoven fabric include polyethylene terephthalate (PET), polypropylene terephthalate, polytetramethylene terephthalate and the like. Examples of nylon constituting the nylon-based fiber non-woven fabric include nylon 6, nylon 66, nylon 610, and nylon 12.

The reinforcing sheet 21 may be made of a porous film. The porous film may be a microporous film having a pore size of 100 μm or less, and examples thereof include a polytetrafluoroethylene film (PTFE film), a polyolefin film, and a polyurethane film. Further, the reinforcing sheet 21 may be made of a woven fabric. Examples of the woven fabric include plain weave, twill weave, satin weave composed of warp and weft, and triaxial weave composed of three-way yarn. Further, the reinforcing sheet 21 may be made of a knitted fabric. Examples of knitted fabrics include round knits such as so-called tenjiku knits and rib knits, weft knits, tricots, and Russell knits.

As shown in FIG. 1 (B), the moisture-permeable waterproof sheet 10 has a structure in which a breathable lining material 31 is adhered to a surface of the open-cell foamed sheet 11 facing the opposite side to the reinforcing sheet 21. May be. The lining material 31 is preferably made of resin from the viewpoint of adhesiveness. Adhesion of the lining material 31 is performed by, for example, a hot melt adhesive. According to the configuration of FIG. 1B, the moisture permeable waterproof sheet 10 can be used as it is as a clothing fabric. Further, by providing the lining material 31, handling and workability such that slipping on the sewing machine table is improved when sewing using the sewing machine is improved. The lining material 31 is preferably made of polyester resin or nylon resin.

[Experimental example]
Hereinafter, the present invention will be described in more detail with reference to experimental examples. The present invention is not limited to these experimental examples.

The samples of Experimental Examples A1 to A3 shown in FIG. 3 are conventional moisture-permeable waterproof sheets. The sample of Experimental Example A1 is a microporous PTFE film. The sample of Experimental Example A2 is a microporous olefin film (composed of polypropylene and an organic filler, having a pore size of 0.3 μm or less). The sample of Experimental Example A3 is a high-density polyethylene non-woven fabric and has a continuous porous structure having a pore size of 100 μm or less. Further, the samples of Experimental Examples A4 to A7 are all open cell foamed sheets obtained by foaming polypropylene or a mixture of polypropylene and elastomer using carbon dioxide in a supercritical state as a foaming agent at a foaming ratio of 10 to 30 times. By observing with an electron microscope, it was confirmed that the bubble diameter of the open cell foam sheets of Experimental Examples A4 to A7 was 50 to 100 μm.

The samples of Experimental Examples B1 to B3 shown in FIG. 4 are obtained by laminating an olefin-based long-fiber non-woven fabric (a spunbonded non-woven fabric having a core-sheath structure in which the core material is polyester and the sheath material is polyethylene) on the open-cell foamed sheet of Experimental Example A4. Is. Similar to Experimental Example A3, this olefin-based long fiber nonwoven fabric has a continuously porous structure having a distribution having a pore diameter of 100 μm or less. In Experimental Example B1, an olefin-based long fiber non-woven fabric (with a grain of 50 g / m ² ) is pressure-bonded to the open-cell foamed sheet (thickness 1.0 mm) of Experimental Example A4 by thermal laminating, and is moisture-permeable and waterproof with a thickness of 0.3 mm. I made a sheet. In Experimental Example B2, an olefin-based long fiber non-woven fabric (with a grain of 50 g / m ² ) is pressure-bonded to the open-cell foamed sheet (thickness 1.0 mm) of Experimental Example A4 by dielectric heating laminating, and is moisture-permeable and waterproof with a thickness of 0.7 mm. I made a sheet. In Experimental Example B3, an olefin-based long fiber non-woven fabric (with a grain of 50 g / m ² ) was pressure-bonded to the open-cell foamed sheet (thickness 1.0 mm) of Experimental Example A4 with a hot melt adhesive, and a transparency of 0.9 mm in thickness was obtained. I made it a wet waterproof sheet. A urethane-based moisture-curable adhesive (Tie Horse NH-300, manufactured by Dainippon Ink and Chemicals Co., Ltd.) was used as the hot-melt adhesive, and it had a dot-like (scattered spot-like) void ratio of 70% and an average adhesion amount. A curtain coat was applied so as to be 20 g / m ² .

<Humidity permeability and water resistance>
Moisture permeability and water resistance were measured for all the samples of Experimental Examples A1 to A7 and B1 to B3. Moisture permeability was measured according to the JIS-L-1099 A-1 method. The water resistance was measured by the water resistance test hydrostatic pressure method A (low water pressure) specified in JIS-L-1092.

<Thermal resistance>
Thermal resistance was measured for the samples of Experimental Examples A1 to A7. The thermal resistance was measured according to JIS A1412-2 heat flow meter method (HFM method). A thermal conductivity measuring device (HC-074, 200 type manufactured by Eiko Seiki Co., Ltd.) was used for the measurement. The test piece was 200 mm × 200 mm. The thermal resistance was measured by inputting the thickness measured by the digital thickness gauge into the above measuring device.

<Tensile load, elongation, tear load>
The tensile load, elongation and tear strength were measured for the samples of Experimental Examples A4 and B1 to B3. Each measurement was performed in two directions, the horizontal direction (TD: Transfer Direction) and the vertical direction (MD: Machine Direction) of the sample. The tensile load and elongation were measured in accordance with JIS K6767. The tear strength was based on the JIS L1096A method (single tongue method). Specifically, a 50 mm × 150 mm test piece was prepared, and a 50 mm notch was made in the center of the short side of the test piece. Then, the distance between the gripping tools was set to 40 mm, and the measurement was performed at a tensile speed of 150 mm / min. AGS-5kNB manufactured by Shimadzu Corporation was used as the tensile tester.

<Examination of experimental results>
From the results of FIG. 3, it can be seen that the open-cell foamed sheets of Experimental Examples A4 to A7 have the same or higher moisture permeability and water resistance as the conventional moisture-permeable waterproof sheets of Experimental Examples A1 to A3. On the other hand, it can be seen that the open bubble wrap sheets of Experimental Examples A4 to A7 have higher thermal resistance than the moisture-permeable waterproof sheets of Experimental Examples A1 to A3. From these results, the open cell foaming sheet (Experimental Examples A4 to A7) using a supercritical fluid as a foaming agent has a moisture permeability and waterproofness equal to or higher than that of the conventional moisture permeable waterproof sheet (Experimental Examples A1 to A3). It can be seen that it has excellent heat insulation performance while having the above. It is considered that the heat insulating performance of Experimental Examples A4 to A7 is derived from the open cell structure of the open cell foam sheet.

From the results of FIG. 4, it can be seen that all of the laminated sheets of Experimental Examples B1 to B3 have higher mechanical strength than the open cell foamed sheets of Experimental Example A4. On the other hand, the laminated sheets of Experimental Examples B1 to B3 have slightly lower moisture permeability and water resistance than the open cell foamed sheets of Experimental Example A4, but according to the comparison with Experimental Example A3 of FIG. 3, Experimental Examples B1 to B1 to It can be seen that the moisture permeability and water resistance of the laminated sheet of B3 are equal to or higher than those of the conventional moisture permeable waterproof sheet, and the influence on practical use is small. This means that the moisture permeability was not impaired by the communication between the bubbles of the open-cell foamed sheet and the pores of the continuous porous structure of the non-woven fabric at the boundary portion between the open-cell foamed sheet and the non-woven fabric.

As described above, from this experimental example, it was confirmed that the moisture-permeable waterproof sheet provided with the open-cell foamed sheet having heat insulating performance as a component exhibits excellent heat insulating performance. It was also confirmed that the strength of the moisture permeable waterproof sheet can be increased by laminating a reinforcing sheet (nonwoven fabric) on the open cell foam sheet. Moreover, the reinforcing sheet has a continuous porous structure, and when the bubbles of the open cell foam sheet and the holes of the reinforcing sheet communicate with each other at the boundary portion between the open cell foam sheet and the reinforcing sheet, the moisture permeability and waterproofness are not impaired. Was confirmed.

10 Moisture permeable waterproof sheet 11 Continuous bubble foam sheet 21 Reinforcing sheet 31 Lining material

Claims (7)

A continuous cell foamed sheet having a bubble diameter of 100 μm or less and a foaming ratio of 10 to 30 times and a reinforcing sheet having a continuous porous structure are provided by laminating them.
At the boundary between the open-cell foamed sheet and the reinforcing sheet, the bubbles of the open-cell foamed sheet and the holes of the reinforcing sheet communicate with each other .
A moisture-permeable waterproof sheet having a hole diameter of 2000 μm or less . A continuous cell foamed sheet having a bubble diameter of 100 μm or less and a foaming ratio of 10 to 30 times and a reinforcing sheet having a continuous porous structure are provided by laminating them.
At the boundary between the open-cell foamed sheet and the reinforcing sheet, the bubbles of the open-cell foamed sheet and the holes of the reinforcing sheet communicate with each other.
The reinforcing sheet is a moisture-permeable waterproof sheet made of an olefin-based long fiber non-woven fabric. A continuous cell foamed sheet having a bubble diameter of 100 μm or less and a foaming ratio of 10 to 30 times and a reinforcing sheet having a continuous porous structure are provided by laminating them.
At the boundary between the open-cell foamed sheet and the reinforcing sheet, the bubbles of the open-cell foamed sheet and the holes of the reinforcing sheet communicate with each other.
The open cell foam sheet and the reinforcing sheet are moisture-permeable waterproof sheets bonded by hot melt adhesives scattered at a plurality of locations. The moisture-permeable waterproof sheet according to any one of claims 1 to 3, wherein the reinforcing sheet is made of a non-woven fabric made of fibers having a core-sheath structure. The moisture-permeable waterproof sheet according to any one of claims 1 to 4, wherein a breathable lining material is laminated on the surface of the open-cell foamed sheet facing the opposite side to the reinforcing sheet. A clothing fabric using a moisture-permeable waterproof sheet provided by laminating an open-cell foamed sheet having a bubble diameter of 100 μm or less and a foaming ratio of 10 to 30 times and a reinforcing sheet having a continuous porous structure.
A clothing fabric in which the bubbles of the open cell foam sheet and the holes of the reinforcing sheet communicate with each other at the boundary portion between the open cell foam sheet and the reinforcing sheet. The clothing fabric according to claim 6, wherein the moisture-permeable waterproof sheet is formed by laminating a breathable lining material on a surface of the open-cell foamed sheet facing the opposite side to the reinforcing sheet.

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