Moisture-permeable waterproof fabric

Abstract

This moisture-permeable waterproof fabric comprises at least a fiber fabric and a porous film laminated on one face of the fiber fabric. The moisture-permeable waterproof fabric is characterized in that: the water pressure resistance measured pursuant to JIS L1092 B method (high water pressure method) before washing is 150 kPa or more; the water pressure resistance after washing for ten times pursuant to JIS L 1930 Appendix F C4M is 50 kPa or more; the moisture permeability measured pursuant to JIS L 1099 A-1 method (calcium chloride method) is 6,000 g / m2･24h; and no fluorine-based compound is contained.

Description

Breathable waterproof fabric

[0001] This invention relates to a breathable and waterproof fabric that combines breathability and waterproofing properties.

[0002] As described in Patent Documents 1 to 3, a breathable waterproof fabric is known in which a porous membrane is laminated on one side of a fibrous fabric. Because the porous membrane has many micropores, a breathable waterproof fabric with a porous membrane has the property of not allowing large water droplets such as raindrops to pass through, but allowing small particles such as water vapor particles to pass through. Therefore, when a breathable waterproof fabric is used in clothing, it is difficult for water such as rain to penetrate into the clothing, but even if the wearer sweats, the inside of the clothing does not become stuffy, resulting in an effect.

[0003] However, a problem with these breathable, waterproof fabrics was that repeated washing caused detergent to accumulate in the numerous micropores of the porous membrane, which reduced the water pressure resistance, an indicator of waterproofness.

[0004] Conventionally, in such breathable waterproof fabrics, a fluorine-based compound has been added to the porous membrane as described in Patent Document 1, or a layer of fluorine-based compound has been provided on top of the porous membrane as described in Patent Document 2. These fluorine-based compounds have the effect of making it difficult for water and detergent to enter the micropores of the porous membrane during washing, and also expelling the water and detergent that have entered the micropores. As a result, breathable waterproof fabrics using fluorine-based compounds did not experience a decrease in water pressure resistance even after repeated washing.

[0005] Furthermore, a wet coagulation method is known as a method for producing porous membranes in breathable waterproof fabrics. Patent Document 3 describes in detail a method for producing breathable waterproof fabrics, including a method for producing porous membranes by wet coagulation.

[0006] Patent No. 5388597 Patent No. 7372257 Patent No. 5490785

[0007] However, in recent years, the use of fluorinated compounds has been restricted worldwide, making it increasingly difficult to use them in breathable waterproof fabrics.

[0008] Therefore, the present invention aims to provide a breathable and waterproof fabric that, despite not containing fluorine-based compounds, possesses both breathability and waterproofing properties, and whose water pressure resistance does not decrease even after repeated washing.

[0009] The present invention includes embodiments shown below.

[0010] [1] A breathable waterproof fabric comprising at least a fibrous fabric and a porous membrane laminated on one side of the fibrous fabric, wherein the water pressure resistance measured by JIS L1092 B method (high water pressure method) before washing is 150 kPa or more, the water pressure resistance after 10 washes in accordance with JIS L 1930 Annex F C4M is 50 kPa or more, and the breathability measured by JIS L 1099 A-1 method (calcium chloride method) is 6000 g / m ２ A breathable, waterproof fabric characterized by having a breathability of 24 hours or more and not containing fluorine-based compounds.

[0011] [2] The breathable waterproof fabric according to [1], wherein the porous membrane comprises a polyurethane resin, inorganic fine particles, and a silicone compound.

[0012] [3] The breathable waterproof fabric according to [1] or [2], wherein the weight ratio of inorganic fine particles to silicone compound in the porous membrane is 30:1 to 4:1.

[0013] [4] A breathable waterproof fabric according to any one of [1] to [3], wherein the pore size of the micropores contained in the porous membrane is 5 μm or less.

[0014] [5] A breathable waterproof fabric according to any one of [1] to [4], wherein a surface treatment layer made of a silicone compound is provided on the surface treatment surface of the porous membrane that is opposite to the surface of the fibrous fabric, and the area of ​​the surface treatment layer is less than 100% of the area of ​​the surface treatment surface.

[0015] The above-mentioned breathable and waterproof fabric, despite not containing fluorine-based compounds, combines breathability and waterproofing, and moreover, its water pressure resistance does not decrease easily even after repeated washing.

[0016] Cross-sectional view of the breathable waterproof fabric of the embodiment. View of the breathable waterproof fabric of the embodiment from the surface treatment layer side. (a) shows the case where the surface treatment layer is provided in a grid pattern. (b) shows the case where the surface treatment layer is provided in a dot pattern. View of the breathable waterproof fabric of the embodiment from the surface treatment layer side. View of the case where the surface treatment layer is mesh-like.

[0017] The embodiments will be described in detail below. Note that the embodiments described below are merely examples, and any modifications made as appropriate without departing from the spirit of the present invention will be included within the scope of the present invention.

[0018] First, let's describe the structure of the breathable waterproof fabric. As shown in Figure 1, the breathable waterproof fabric 1 of this embodiment has a porous membrane 3 laminated on one side of a fiber fabric 2, and a surface treatment layer 4 laminated on top of the porous membrane 3 (on the side opposite to the fiber fabric 2).

[0019] As the textile fabric 2, woven fabrics, knitted fabrics, nonwoven fabrics, etc., can be used. Preferred fabrics include plain weave fabrics and ripstop fabrics. Plain weave fabrics tend to have a flat surface, and ripstop fabrics have high strength. Various fibers can be used as the fibers that make up the textile fabric 2, such as synthetic fibers such as polyamide fibers, polyester fibers, acrylic fibers, and polyurethane fibers, natural fibers such as cotton, linen, silk, and wool, and regenerated fibers such as rayon and cupro. Synthetic fibers are preferred because they are less likely to get wet. In addition, the textile fabric 2 may be composed of two or more types of fibers.

[0020] It is preferable that the textile fabric 2 is treated with a water-repellent finish. The water-repellent agent used for the treatment is a non-fluorine-based water-repellent agent such as a silicone-based water-repellent agent or a paraffin-based water-repellent agent. By treating the textile fabric 2 with a water-repellent finish, the waterproofness of the breathable waterproof fabric 1 is enhanced. In addition, the textile fabric 2 may be treated with various processes such as flame retardant treatment, calendering, antistatic treatment, and dyeing, as needed.

[0021] The thickness of the fiber fabric 2 is, for example, 20 μm or more and 1000 μm or less. However, the thickness of the fiber fabric 2 is determined by the intended use of the breathable waterproof fabric 1, etc., and is not limited to the above thickness.

[0022] The porous membrane 3 is a membrane in which numerous micropores are formed. In the porous membrane 3, the micropores are interconnected. The chain of numerous micropores extends three-dimensionally within the porous membrane 3 and also extends from one surface of the porous membrane 3 to the other surface.

[0023] The pore size (diameter) of the micropores in the porous membrane 3 is 5 μm or less. Furthermore, the pore size of the micropores is preferably 30% or less of the thickness of the porous membrane 3. Because numerous micropores with a pore size of 5 μm or less are interconnected, water particles (with a particle size of approximately 0.04 μm) and water vapor particles (with a particle size of approximately 0.4 nm) generated from sweat can permeate from one surface of the porous membrane 3 to the other. On the other hand, because the pore size of the micropores is 5 μm or less, raindrops (with a particle size of approximately 3000 μm in the case of thunderstorms, approximately 2000 μm in the case of normal rain, and approximately 100 μm in the case of drizzle) cannot permeate the porous membrane 3. Also, in the very surface skin layer of the porous membrane 3, the pore size of the micropores is less than 1 μm.

[0024] Furthermore, the fibrous fabric 2 has gaps larger than the pore diameter of the micropores in the porous membrane 3. Therefore, particles that can permeate the porous membrane 3 can also pass through the fibrous fabric 2.

[0025] The thickness of the porous membrane 3 is preferably 15 μm to 80 μm, and more preferably 25 μm to 60 μm. The preferred thickness of the porous membrane 3 makes it easier to achieve both moisture permeability and waterproofing. The density of the porous membrane 3 is not limited, but for example, 0.5 g / cm³ is preferable. ３ 1.5g / cm or more ３ The following applies:

[0026] The porous membrane 3 contains polyurethane resin, inorganic fine particles, and a silicone-based compound. The porous membrane 3 may also contain, as needed, components such as pigments, UV absorbers, and antibacterial agents, provided that these do not impair its moisture permeability and waterproofing properties.

[0027] Examples of polyurethane resins used in the porous membrane 3 include polyester-based polyurethane, polycarbonate-based polyurethane, polyether-based polyurethane, and polyether ester-based polyurethane. In particular, it is preferable that either polyester-based polyurethane or polycarbonate-based polyurethane, or both, are used. When polycarbonate-based polyurethane is included in the porous membrane 3, deterioration of the porous membrane 3 due to hydrolysis and a decrease in water pressure resistance are less likely to occur.

[0028] The polyurethane resin is preferably one with a solidification value of 3% by weight or more and 15% by weight or less. A smaller solidification value indicates higher hydrophobicity, and a larger value indicates higher hydrophilicity. A smaller solidification value also indicates faster solidification. A solidification value of 3% by weight or more in the polyurethane resin makes it easier to form uniform and fine pores in the porous membrane 3. Furthermore, a solidification value of 15% by weight or less in the polyurethane resin prevents the porous membrane 3 from becoming too hydrophilic, resulting in a porous membrane 3 with excellent waterproofing properties.

[0029] The polyurethane resin content in the porous membrane 3 is preferably 60% to 80% by weight, and more preferably 60% to 70% by weight, relative to the total solid content of the porous membrane 3. Because the main component of the porous membrane 3 is polyurethane resin, the porous membrane 3 and the breathable waterproof fabric 1 using it become elastic, resulting in a comfortable garment when the breathable waterproof fabric 1 is used for clothing. Furthermore, if the polyurethane resin content is 60% to 80% by weight as described above, a good balance is achieved between the waterproofness, water particle permeability, and texture (elasticity) of the porous membrane 3.

[0030] Examples of inorganic fine particles used in the porous membrane 3 include silica, such as silicon dioxide, and carbonates, such as calcium carbonate. The porous membrane 3 may use only one type of inorganic fine particle, or it may use a mixture of two or more types of inorganic fine particles. The inorganic fine particles are particularly preferably silicon dioxide particles.

[0031] Because inorganic microparticles have a high affinity for polar organic solvents, the concentration of the polar organic solvent increases around the inorganic microparticles during the manufacturing process of the porous membrane, which will be described later. As the polar organic solvent portion becomes a micropore, many micropores are formed around the inorganic microparticles.

[0032] The average particle size of the inorganic fine particles is preferably between 5 nm and 5 μm. This particle size allows for the formation of fine pores of a preferred size in the porous membrane 3. Furthermore, the inorganic fine particle content in the porous membrane 3 is preferably between 10% by weight and 40% by weight relative to the total solid content of the porous membrane 3. A content of 10% by weight or more of inorganic fine particles facilitates the formation of numerous fine pores in the porous membrane 3, improving its moisture permeability. Additionally, a content of 40% by weight or less of inorganic fine particles ensures that the porous membrane 3 possesses sufficient strength.

[0033] Various water-repellent silicone compounds can be used as the silicone compound for the porous membrane 3, including dimethyl silicone, alcohol-modified dimethyl silicone, alkoxy-modified dimethyl silicone, amino-modified silicone, acrylic-modified silicone, urethane-modified silicone, methyl hydrogen dimethyl silicone, organohydrogen polysiloxane, and compounds derived from these (for example, copolymers of any of the above silicone compounds with synthetic resins such as acrylic resins).

[0034] In order to form a large number of micropores in the porous membrane 3, it is preferable that the content of inorganic fine particles in the porous membrane 3 be relatively high. However, inorganic fine particles have the property of attracting detergent, and if the porous membrane 3 contains many inorganic fine particles, detergent can easily enter the micropores during washing. Also, because the micropores are small, the detergent that enters the micropores has difficulty to escape. Therefore, if the content of inorganic fine particles in the porous membrane 3 is high, detergent may remain in the micropores after repeated washing, which may reduce the washability of the breathable waterproof fabric 1.

[0035] However, because the porous membrane 3 contains a silicone compound, the hydrophobic properties of the silicone compound are utilized, which inhibits detergent from entering the micropores along with water, and also facilitates the discharge of water and detergent that have entered the micropores. As a result, detergent is less likely to remain in the micropores even after repeated washing, and the washability of the breathable waterproof fabric 1 does not deteriorate easily.

[0036] Based on these findings regarding inorganic fine particles and silicone compounds, it is preferable that the porous membrane 3 contains inorganic fine particles and silicone compounds in a certain ratio. Specifically, in the porous membrane 3, it is preferable that the weight ratio of inorganic fine particles to silicone compounds is 30:1 to 4:1. That is, it is preferable that the weight of inorganic fine particles is 4 to 30 for every 1 unit of weight of silicone compound. Furthermore, it is more preferable that the weight ratio of inorganic fine particles to silicone compounds is 9:1 to 4:1. By achieving these ratios, many micropores can be formed in the porous membrane 3, and a moderate degree of hydrophobicity is generated in the porous membrane 3 without deteriorating its moisture permeability. As a result, detergent is less likely to remain in the micropores, and the washability of the moisture-permeable waterproof fabric 1 is less likely to decrease.

[0037] The tensile elongation of the porous membrane 3 is preferably 150% or more, and more preferably 200% or more. Conventional porous membranes mainly composed of polyolefin or fluorine-based materials have a tensile elongation of less than 100%, but in this embodiment, the high tensile elongation of the porous membrane 3 makes the breathable waterproof fabric 1 more flexible than conventional ones. Tensile elongation refers to the tensile elongation measured in accordance with JIS K 7127, under the conditions of a sample width of 25 mm, a gripping distance of 50 mm, and a tensile speed of 200 mm / min.

[0038] The surface treatment layer 4 is provided on the surface of the porous membrane 3 opposite to the fiber fabric 2 (this surface is referred to as the "surface treatment surface") among the two surfaces of the porous membrane 3. The surface treatment layer 4 is not provided over the entire surface treatment surface, but is provided so as to cover a predetermined ratio (less than 100%) of the area of the surface treatment surface. It is sufficient if there is at least a small portion on the surface treatment surface of the porous membrane 3 where the surface treatment layer 4 is not present. Under such conditions, it is preferable that the ratio of the area of the surface treatment layer 4 to the area of the surface treatment surface is closer to 100%. As a specific numerical value, the ratio of the area of the surface treatment layer 4 to the area of the surface treatment surface is preferably 15% or more and 98% or less, and more preferably 40% or more and 97% or less. Note that the area of the surface treatment surface is the combined area of the portion where the surface treatment layer 4 is provided and the portion where it is not provided.

[0039] The surface treatment layer 4 is made of a non-fluorine-based compound such as a silicone-based compound or a urethane resin, and has water repellency. It is particularly preferable that the surface treatment layer 4 is made of a silicone-based compound. As the silicone-based compound used for the surface treatment layer 4, the above-mentioned silicone-based compound contained in the porous membrane 3 can be used. Due to the water and oil repellency of the silicone-based compound, it becomes difficult for sweat, sebum, dirt, etc. to adhere to the porous membrane 3, and deterioration and functional decline of the porous membrane 3 are less likely to occur.

[0040] Since the surface treatment layer 4 is provided, it is difficult for the detergent to enter the micropores of the porous membrane 3 during washing, and the wash durability of the moisture permeable and waterproof fabric 1 is less likely to decrease. Also, since the ratio of the area of the surface treatment layer 4 to the area of the porous membrane 3 is less than 100%, it is difficult to inhibit the permeation of water vapor particles, etc. in the porous membrane 3, and the moisture permeability of the moisture permeable and waterproof fabric 1 is less likely to decrease. If the ratio of the area of the surface treatment layer 4 to the area of the porous membrane 3 is 15% or more and 98% or less, the balance between the wash durability and the moisture permeability of the waterproof fabric 1 is good, and if this ratio is 40% or more and 97% or less, the balance between the wash durability and the moisture permeability is even better.

[0041] It is preferable that the surface treatment layer 4 forms a pattern that is evenly disposed over the entire porous membrane 3. As such a pattern, a periodic pattern such as the lattice pattern shown in Fig. 2(a), the dot pattern shown in Fig. 2(b), the mesh pattern shown in Fig. 3, or a checked pattern (not shown) is preferable. Also, the pattern may be random.

[0042] The fiber fabric 2 and the porous membrane 3 are adhered by an adhesive. As the adhesive, various types of adhesives such as hot melt type, organic solvent type, and water-based type can be used. Among them, a moisture-curing hot melt urethane adhesive is preferable in terms of adhesiveness and flexibility.

[0043] The adhesive is not provided over the entire joint surface between the fiber fabric 2 and the porous membrane 3, but is provided in an area portion of a predetermined ratio (less than 100%) of the entire joint surface. Thereby, it is difficult for the adhesive to inhibit the moisture permeability of the moisture-permeable waterproof fabric 1. The ratio of the area of the portion where the adhesive is provided to the area of the entire joint surface between the fiber fabric 2 and the porous membrane 3 is preferably 15% or more and 60% or less.

[0044] It is preferable that the adhesive for adhering the fiber fabric 2 and the porous membrane 3 forms a pattern that is evenly disposed over the entire joint surface. As such a pattern, a periodic pattern such as a lattice pattern, a dot pattern, or a mesh pattern, similar to the surface treatment layer 4, is preferable.

[0045] At the location where the fiber fabric 2 and the porous membrane 3 are adhered by the adhesive, a layer composed only of the adhesive is formed between the fiber fabric 2 and the porous membrane 3.

[0046] Next, we will explain the performance of breathable waterproof fabrics. The porous membrane of breathable waterproof fabrics has numerous micropores, but these micropores are small, preventing large water droplets such as raindrops from passing through the porous membrane. Therefore, breathable waterproof fabrics have high waterproofness (water pressure resistance). Furthermore, because the porous membrane contains silicone-based compounds, even though the porous membrane does not contain fluorine-based compounds, it has washability as described above and maintains high water pressure resistance even after repeated washing. Additionally, because the porous membrane has numerous micropores, water vapor particles can pass through it, resulting in high breathability. Breathable waterproof fabrics also possess water-repellent properties. These properties will now be explained.

[0047] First, the breathable waterproof fabric has a water pressure resistance of 150 kPa or more before washing. More preferably, the water pressure resistance before washing is 200 kPa or more. Furthermore, the breathable waterproof fabric has a water pressure resistance of 50 kPa or more after 10 washes. More preferably, the water pressure resistance after 20 washes is 100 kPa or more. High water pressure resistance after 10 or 20 washes means high washability.

[0048] Here, water pressure resistance refers to the water pressure resistance measured by JIS L 1092 Method B (high water pressure method). Water pressure resistance is an indicator of waterproofness, and the higher the value, the more waterproof the product. Furthermore, washing refers to washing in accordance with JIS L 1930 Annex F C4M.

[0049] Furthermore, the breathable waterproof fabric has a breathability of 6000 g / m² as measured by the JIS L 1099 A-1 method (calcium chloride method). ２ - It is 24 hours or more. More preferably, the moisture permeability measured by the A-1 method above is 10,000 g / m ２ • 24 hours or more. Note: g / m ２ 24h is 1m ２ This refers to the weight of water vapor that permeates per 24-hour period.

[0050] Further, the moisture-permeable waterproof fabric preferably satisfies the above numerical values for the moisture permeability measured by the above A-1 method, and further preferably satisfies a predetermined numerical value for the JIS L 1099 B-1 method (potassium acetate method). Specifically, the moisture permeability measured by the above B-1 method is preferably 10000 g / m ２ ·24 h or more, and more preferably 15000 g / m ２ ·24 h or more.

[0051] Further, the moisture-permeable waterproof fabric preferably has a water repellency of 4th grade or higher (i.e., 4th or 5th grade) before washing. Here, the water repellency is the grade determined by the spray test of JIS L 1092.

[0052] Further, the moisture-permeable waterproof fabric preferably satisfies the condition that the water repellency before washing is 4th grade or higher, and the water repellency after 20 times of washing is 3rd grade or higher (i.e., 3rd, 4th or 5th grade). Here, the washing is the washing in accordance with Appendix F C4M of JIS L 1930.

[0053] Next, an example of the method for manufacturing the moisture-permeable waterproof fabric will be described. As a general process, a porous membrane is formed by the wet coagulation method, the porous membrane is adhered to a fiber fabric, and further a compound (surface treatment agent) serving as a surface treatment layer is applied on the porous membrane. The specific method will be described.

[0054] First, a porous membrane is formed on a peelable substrate. As a specific method, first, a solution containing a polyurethane resin, inorganic fine particles, a silicone-based compound and a polar organic solvent is applied to one side of the peelable substrate. Thereby, a solution layer is formed on the peelable substrate.

[0055] Here, as the polar organic solvent, one or a combination of two or more known polar organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, and N-methylpyrrolidone is used. N,N-dimethylformamide is particularly preferred as the polar organic solvent. Furthermore, the releaseable substrate can be any material that has release properties to the porous film completed on the releaseable substrate. For example, a film made of resin such as olefin resin or silicone resin can be used as the releaseable substrate. Alternatively, a release agent may be applied to paper, fabric, or resin film as the releaseable substrate.

[0056] In the solution layer on the releaseable substrate, inorganic fine particles and a polar organic solvent are dispersed. Because the inorganic fine particles have a high affinity for the polar organic solvent, the concentration of the polar organic solvent is higher around the inorganic fine particles.

[0057] Next, the solution layer on the releaseable substrate is exposed to a gas phase in which water droplets are uniformly dispersed. The average diameter of the water droplets is, for example, between 1 μm and 30 μm. The temperature of the gas phase is, for example, between 5°C and 50°C. Methods for exposing the solution layer to the gas phase include placing the releaseable substrate coated with the solution layer into a tank filled with the gas phase, or blowing the gas phase onto the solution layer on the releaseable substrate.

[0058] When the solution layer on the release substrate is exposed to the gas phase, water droplets adhere to the surface of the solution layer, and solidification of the solution begins at the surface of the solution layer. The solution layer then enters a semi-solid state where solidification is progressing at the surface, but not yet progressing internally.

[0059] It should be noted that the step in which the solution layer is exposed to the gas phase and reaches a semi-solid state is not essential and can be omitted.

[0060] Next, a releaseable substrate having a semi-solidified solution layer is immersed in water. The water temperature is, for example, between 0°C and 70°C, and the immersion time is, for example, between 30 seconds and 10 minutes. Immersion in water allows water to penetrate the solution layer, replacing the polar organic solvent in the solution layer with water, and solidification progresses to the interior of the solution layer. As a result, the original solution layer becomes a solidified layer with water dispersed inside.

[0061] Next, the solidified layer on the releaseable substrate is dried. The drying temperature is, for example, between 50°C and 150°C, and the drying time is, for example, between 1 minute and 10 minutes. Through drying, the water inside the solidified layer evaporates, and the areas where water originally existed become micropores. As a result, a porous membrane with numerous micropores is completed on the releaseable substrate.

[0062] In addition to the porous membrane, a fibrous fabric is prepared. The fibrous fabric is knitted or otherwise prepared using a known method, and is preferably treated with a water-repellent agent that is not fluorine-based. The water-repellent treatment is applied using a known method such as padding or spraying.

[0063] Next, the porous membrane is peeled off the release substrate and bonded to one side of the fibrous fabric with an adhesive. Alternatively, the porous membrane, while still resting on the release substrate, is bonded to one side of the fibrous fabric with an adhesive, and then the release substrate is peeled off the porous membrane. The adhesive used is, as described above, a hot-melt adhesive or the like. It is preferable that the adhesive is applied not to the entire bonding surface between the fibrous fabric and the porous membrane, but to form a pattern such as a grid, dots, or mesh.

[0064] Next, a compound (surface treatment agent), which is the raw material for the surface treatment layer, is applied to the surface of the porous membrane that has been bonded to the fibrous fabric. As mentioned above, the compound used as the raw material for the surface treatment layer is, for example, a silicone-based compound. Such a compound is not applied to the entire surface of the porous membrane, but rather to a predetermined proportion of the surface area of ​​the porous membrane. Once the applied compound dries, the surface treatment layer is completed.

[0065] In this way, a porous membrane is laminated on the fibrous fabric, and a surface treatment layer is laminated on the porous membrane 3 to complete a breathable waterproof fabric. The manufacturing method described here can be modified as appropriate. For example, the porous membrane may be formed directly on the fibrous fabric. However, the method of forming the porous membrane on a releaseable substrate and then adhering it to the fibrous fabric allows for the lamination of the porous membrane on a wider variety of fibrous fabrics (for example, fibrous fabrics on which it is difficult to form a porous membrane directly) than the method of forming the porous membrane directly on the fibrous fabric.

[0066] The breathable waterproof fabric of this embodiment can be used in a variety of applications where it is required to suppress the intrusion of water such as rain and to suppress stuffiness. Specific applications of the breathable waterproof fabric include, for example, sportswear (running and cycling wear, etc.), outdoor clothing (jackets and pants for mountaineering and hiking, etc.), cold-weather clothing (gloves and hats, etc.), outdoor equipment (tents and sleeping bags, etc.), footwear (rain boots and snow boots, etc.), waders, bags, etc. Furthermore, because the porous membrane of the breathable waterproof fabric of this embodiment contains polyurethane resin and has high elasticity, it is suitable for use in products and parts where stretchability is required. When the breathable waterproof fabric is used in clothing, it is used with the porous membrane facing the skin and the fibrous fabric facing outwards.

[0067] When the breathable waterproof fabric of this embodiment is used in clothing, the high waterproofness of the fabric makes it difficult for water to penetrate the clothing, and the high breathability of the fabric prevents sweat from the wearer from accumulating inside the clothing, thus reducing stuffiness. Furthermore, the performance does not deteriorate easily even after repeated washing of the clothing. The same applies when the breathable waterproof fabric of this embodiment is used in items other than clothing.

[0068] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. [Example 1] A nylon fabric was prepared as a textile using 66 nylon false-twist yarn of 22 dtex / 20 filaments for both the warp and weft threads, and was scouring and dyed by conventional methods. Next, the textile was immersed in a 5% by weight aqueous dispersion of a non-fluorine water repellent ("Neoseed NR-158," manufactured by Nikka Chemical Co., Ltd.), squeezed with a mangle (squeezing rate: approximately 40%), dried at 120°C for 1 minute, and then heat-treated at 160°C for 1 minute.

[0069] Next, a polyester film with a release treatment applied to its surface was prepared as a release substrate, and a porous film was formed on it by a wet solidification method. Specifically, first, a resin solution with the composition shown in Formulation 1 was applied to the polyester film using a knife coater so that the thickness after drying was approximately 35 μm. Next, the polyester film coated with the resin solution was exposed to a gas phase in which water droplets were uniformly dispersed by running it in an exposure device equipped with a water spray humidifier. Then, the polyester film was immersed in water at 15°C for 1.5 minutes to completely solidify the resin solution, immersed in warm water at 50°C for 5 minutes, and then dried at 130°C for 2 minutes. Thus, the porous film of Example 1 was obtained. <Formulation 1> 1) Rezamin CU-8614; 80 parts by weight (Polycarbonate-based polyurethane resin solution, manufactured by Dainichi Seika Kogyo Co., Ltd.) 2) Rezamin CU-4340NS; 20 parts by weight (Polyester-based polyurethane resin solution, manufactured by Dainichi Seika Kogyo Co., Ltd.) 3) Aerosil R972; 10 parts by weight (Silicon dioxide fine particles, particle size: approximately 17 nm, manufactured by Nippon Aerosil Co., Ltd.) 4) NipSeal SS-50F; 1.5 parts by weight (Silicon dioxide fine particles, average particle size: approximately 1.2 μm, manufactured by Tosoh Silica Co., Ltd.) 5) Drypon 600E; 3 parts by weight (Silicone emulsion, manufactured by Nikka Chemical Co., Ltd.) 6) Drypon Z-7; 3 parts by weight (Organic acid zinc compound, catalyst for the above silicone, manufactured by Nikka Chemical Co., Ltd.) 7) N,N-dimethylformamide; 50 parts by weight Next, the porous membrane was bonded to the back surface of the fiber fabric using a moisture-curing hot-melt polyurethane adhesive ("Tiforce NH-321", manufactured by DIC Corporation) (in a fine dot pattern, bonding area: approximately 30%), and after the adhesive had sufficiently cured, the polyester film was peeled off to obtain a moisture-permeable waterproof fabric in which the fiber fabric and the porous membrane were laminated.

[0070] Next, the surface treatment agent shown in Formulation 2 was applied to the surface (surface treatment surface) of the porous membrane of the aforementioned breathable waterproof fabric using a gravure coater equipped with a 40-mesh roll, and dried at 130°C for 1 minute to form a surface treatment layer. Thus, the breathable waterproof fabric of Example 1 was obtained. <Formulation 2> 1) Solven S-2610; 100 parts by weight (silicone compound, manufactured by Kyoken Kasei Co., Ltd.) 2) Solven 800; 15 parts by weight (polyurethane resin, manufactured by Kyoken Kasei Co., Ltd.) 3) Petroleum solvent: 50 parts by weight A 40-mesh roll is a roll on which 40 square pockets are engraved per inch (25.4 mm), resulting in 1600 square pockets per inch x 1 inch area on the outer surface. In the gravure coater, the surface treatment agent accumulated in these pockets is transferred to the surface treatment surface of the porous membrane. As a result, 1600 square surface treatment layers 4 are formed on the surface treatment surface of the porous membrane for each 1-inch x 1-inch area, as shown in Figure 3. In addition, the parts of the porous membrane 3 that are not covered by the surface treatment layer 4 appear as a grid consisting of many vertical and horizontal lines. In Example 1, which uses this 40-mesh roll, the ratio of the area of ​​the surface treatment layer 4 to the area of ​​the surface treatment surface of the porous membrane 3 is 97%. [Example 2] A breathable waterproof fabric of Example 2 was obtained in the same manner as in Example 1, except that the surface treatment was omitted. [Example 3] A breathable waterproof fabric of Example 3 was obtained in the same manner as in Example 1, except that the amount of Aerosil R972 in the resin solution of Formulation 1 was set to 15 parts, and the amount of N,N-dimethylformamide was adjusted so that the viscosity of the resin solution was the same as in Formulation 1. [Example 4] A breathable waterproof fabric of Example 4 was obtained in the same manner as in Example 3, except that the surface treatment was performed twice. [Example 5] In Example 3, the gravure roll used for surface treatment was changed from 40 mesh to 120 mesh (120 pockets per inch), and the coating area was reduced. Except for this change, the breathable waterproof fabric of Example 5 was obtained in the same manner as in Example 3. [Example 6] In Example 3, the surface treatment was omitted. Except for this change, the breathable waterproof fabric of Example 6 was obtained in the same manner as in Example 3.[Example 7] A breathable waterproof fabric of Example 7 was obtained in the same manner as in Example 1, except that the amount of Drypon 600E and Drypon Z-7 in the resin solution of Formulation 1 was set to 7 parts each, the amount of N,N-dimethylformamide was adjusted so that the viscosity of the resin solution was the same as that of Formulation 1, and the surface treatment was omitted. [Comparative Example 1] A breathable waterproof fabric of Comparative Example 1 was obtained in the same manner as in Example 2, except that the amount of Drypon 600E and Drypon Z-7 in the resin solution of Formulation 1 was changed to 13 parts of Solven EF-2400 (hydrocarbon compound, manufactured by Kyoken Kasei Co., Ltd.), and the amount of N,N-dimethylformamide was adjusted so that the viscosity of the resin solution was the same as that of Formulation 1. [Comparative Example 2] A breathable waterproof fabric of Comparative Example 2 was obtained in the same manner as in Example 2, except that Drypon 600E and Drypon Z-7 were omitted from the resin solution of Formulation 1, and the amount of N,N-dimethylformamide was adjusted so that the viscosity of the resin solution was the same as that of Formulation 1. [Reference Example] A breathable waterproof fabric of Reference Example was obtained in the same manner as in Example 2, except that Drypon 600E and Drypon Z-7 were replaced with 7.5 parts of Asahi Guard AG-E082 (fluorine-based water and oil repellent agent, manufactured by AGC Inc.) in the resin solution of Formulation 1, and the amount of N,N-dimethylformamide was adjusted so that the viscosity of the resin solution was the same as that of Formulation 1.

[0071] Tables 1 and 2 summarize the composition of the completed porous films and the characteristics of the surface treatment layers for Examples 1-7, Comparative Examples 1-2, and Reference Examples.

[0072] For each breathable waterproof fabric, the moisture permeability and water pressure resistance were measured according to the respective standards described above. Additionally, the tensile elongation of each porous membrane was measured according to the same standards. The measurement results are shown in Tables 1 and 2, confirming that each example exhibited sufficient breathability, water pressure resistance (waterproofing), and washability.

[0073]

[0074]

[0075] 1... Breathable waterproof fabric, 2... Fiber fabric, 3... Porous membrane, 4... Surface treatment layer

Claims

1. A breathable waterproof fabric comprising at least a fibrous fabric and a porous membrane laminated on one side of the fibrous fabric, wherein the water pressure resistance measured by JIS L1092 Method B (high water pressure method) before washing is 150 kPa or more, the water pressure resistance after 10 washes in accordance with JIS L 1930 Annex F C4M is 50 kPa or more, and the breathability measured by JIS L 1099 Method A-1 (calcium chloride method) is 6000 g / m². ２ A breathable, waterproof fabric characterized by having a breathability of 24 hours or more and not containing fluorine-based compounds.

2. The breathable waterproof fabric according to claim 1, wherein the porous membrane comprises a polyurethane resin, inorganic fine particles, and a silicone-based compound.

3. The breathable waterproof fabric according to claim 1 or 2, wherein the weight ratio of inorganic fine particles to silicone-based compound in the porous membrane is 30:1 to 4:

1.

4. The breathable waterproof fabric according to claim 1 or 2, wherein the pore size of the micropores contained in the porous membrane is 5 μm or less.

5. The breathable waterproof fabric according to claim 1 or 2, wherein a surface treatment layer made of a silicone compound is provided on the surface treatment surface of the porous membrane that is opposite to the surface of the fibrous fabric, and the area of ​​the surface treatment layer is less than 100% of the area of ​​the surface treatment surface.

6. The breathable waterproof fabric according to claim 1 or 2, wherein the tensile elongation of the porous membrane is 150% or more.

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