Moisture-permeable waterproof film and laminate article comprising same

Abstract

An embodiment of the present invention provides a moisture-permeable waterproof film comprising: a polyolefin-based porous film; and a hydrophilic polymer applied to the surface of the polyolefin-based porous film by using a solution containing the hydrophilic polymer and a solvent, wherein the moisture-permeable waterproof film satisfies the following expression. Expression: 4 ≤ (C*D) / (A*B) ≤ 8 In the expression, A is the thickness (µm) of the polyolefin-based porous film, B is the air permeability (Gurley, sec / 100 ml) of the polyolefin-based porous film, C is the porosity (vol %) of the polyolefin-based porous film, and D is the solid content (wt%) of the hydrophilic polymer in the solution.

Description

Breathable waterproof film and laminate article containing the same

[0001] This specification relates to a breathable waterproof film and a laminate article containing the same.

[0002] Clothing, shoes, gloves, hats, etc., often include a layer possessing both breathability and waterproofness—so-called a breathable waterproof layer. This breathable waterproof layer can provide a comfortable wearing experience by keeping the wearer dry in humid conditions. Specifically, the breathable waterproof layer allows water vapor, such as sweat, inside the garment to pass through and be released to the outside, while preventing external moisture from penetrating into the garment. By keeping the garment waterproof from rain or snow and allowing sweat to escape, it helps regulate the wearer's body temperature and maintains comfort. With the recent increase in interest in health and leisure activities, fabrics incorporating breathable waterproof layers are being applied in various fields.

[0003] As a representative breathable waterproof fabric, the breathable waterproof film manufactured using a microporous PTFE membrane and hydrophilic polyurethane is currently GORE-TEX ® It is used in the manufacture of fabric laminates. Although the pore size of the PTFE membrane is larger than a water molecule, the pores are much smaller than individual water droplets; therefore, water vapor can pass through the membrane, whereas water droplets cannot. However, GORE-TEX ® Fluoropolymer resins, the main raw material for fabrics, are expensive and heavy, and are particularly harmful to the human body and the surrounding environment, so regulations are being tightened.

[0004] In response to this, there have been attempts to replace PTFE membranes with non-fluorinated resins such as polyester, but using non-fluorinated resins results in reduced breathability, moisture permeability, softness, and tactile feel compared to PTFE membranes, and causes or increases noise during bending and / or friction. Additionally, conventional breathable waterproof fabrics have a problem in which surfactants penetrate between the pores during the washing process, causing a significant decrease in waterproof performance after washing.

[0005] Accordingly, there is a need to develop a breathable waterproof film that uses a non-fluorinated resin, has excellent breathability and water permeability and breathability, produces less noise upon friction, and has an excellent tactile feel, thereby providing a comfortable wearing experience when applied to items such as clothing, shoes, gloves, and hats, while also having excellent washing durability.

[0006] The details of this specification are intended to solve the problems of the aforementioned prior art, and one objective of this specification is to provide a breathable waterproof film that has excellent breathability and water permeability and breathability, while also having low noise during friction, excellent tactile feel, and excellent washing durability, and a laminate article containing the same.

[0007] According to one aspect, a moisture-permeable waterproof film is provided, comprising: a polyolefin-based porous film; and a hydrophilic polymer applied to the surface of the polyolefin-based porous film by a solution comprising a hydrophilic polymer and a solvent, satisfying the following formula.

[0008] <Food>

[0009] 4 ≤ (C*D) / (A*B) ≤ 8

[0010] In the above formula, A is the thickness (μm) of the polyolefin-based porous film, B is the air permeability (Gurley, sec / 100ml) of the polyolefin-based porous film, C is the porosity (volume%) of the polyolefin-based porous film, and D is the solid content (weight%) of the hydrophilic polymer in the solution.

[0011] In one embodiment, the polyolefin-based porous film may be formed from one polyolefin-based resin selected from the group consisting of polyethylene, polypropylene, polybutylene, polymethylpentene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations of two or more of these.

[0012] In one embodiment, the thickness of the polyolefin-based porous film may be 5 to 100 μm.

[0013] In one embodiment, the air permeability (Gurley) of the polyolefin-based porous film may be 10 to 40 seconds / 100 ml.

[0014] In one embodiment, the porosity of the polyolefin-based porous film may be 60 to 90 volume%.

[0015] In one embodiment, the hydrophilic polymer may be one selected from the group consisting of ethylene vinyl acetate, ethylene vinyl alcohol, polyvinyl alcohol, polyacrylic acid, polyoxyethylene-polyoxypropylene block copolymer, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl butyral, cellulose derivative, polyurethane, polyamide, polyester, glycerol, and combinations of two or more of these.

[0016] In one embodiment, the solvent is water, NMP (N-Methyl-2-pyrrolidone), acetone, DMF (N,N-dimethylformamide), DMSO (Dimethyl sulfoxide), CHP (Cyclohexyl-pyrrolidinone), N12P (N-dodecyl-pyrrolidone), benzyl benzoate, N8P (N-Octyl-pyrrolidone), DMEU (dimethyl-imidazolidinone), cyclohexanone, DMA (dimethylacetamide), NMF (N-Methyl Formamide), bromobenzene, chloroform, chlorobenzene, benzonitrile, quinoline, benzyl ether, ethanol, isopropyl alcohol, methanol, butanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, THF (tetrahydrofuran), ethylene glycol, pyridine, It may be one selected from the group consisting of N-vinylpyrrolidone, methyl ethyl ketone, alpha-terffinol, formic acid, ethyl acetate, acrylonitrile, toluene, and combinations of two or more of these.

[0017] In one embodiment, the solid content of the hydrophilic polymer in the solution may be 15 to 35 weight percent.

[0018] In one embodiment, the water pressure resistance of the breathable waterproof film measured according to ATCC127 may be 9,000 to 20,000 mmH2O.

[0019] In one embodiment, the water vapor transmission rate (MVTR) of the breathable waterproof film, measured in accordance with DIN EN ISO 15496, is 5,000 to 20,000 g / m² 2 It can be / 24hr.

[0020] According to another aspect, a laminate article is provided comprising: the above-mentioned breathable waterproof film; and at least one layer bonded in contact with the above-mentioned breathable waterproof film.

[0021] In one embodiment, the layer may include one selected from the group consisting of a textile layer, a polymer film layer, a natural leather layer, a synthetic leather layer, a fleece layer, and a combination of two or more of these.

[0022] A breathable waterproof film according to one aspect of the present specification and a laminated article containing the same have excellent breathability and water permeability and breathability, while also having low noise and excellent tactile feel when applied to articles such as clothing, shoes, gloves, and hats, and can provide a comfortable wearing experience, and have excellent washing durability so that excellent breathability and water permeability can be maintained even after washing.

[0023] The effects of one aspect of this specification are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configurations described in the detailed description or claims of this specification.

[0024] Hereinafter, one aspect of this specification will be described based on specific examples. However, the details described in this specification may be implemented in various different forms and are therefore not limited to the embodiments described herein.

[0025] Throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0026] When a range of numerical values ​​is described in this specification, unless a specific range is otherwise described, the value has the precision of significant figures provided according to the standard rules in chemistry for significant figures. For example, 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49.

[0027] breathable waterproof film

[0028] A moisture-permeable waterproof film according to one aspect of the present specification comprises: a polyolefin-based porous film; and a hydrophilic polymer applied to the surface of the polyolefin-based porous film by a solution comprising a hydrophilic polymer and a solvent, and satisfies the following formula.

[0029] <Food>

[0030] 4 ≤ (C*D) / (A*B) ≤ 8

[0031] In the above formula, A is the thickness (μm) of the polyolefin-based porous film, B is the air permeability (Gurley, sec / 100ml) of the polyolefin-based porous film, C is the porosity (volume%) of the polyolefin-based porous film, and D is the solid content (weight%) of the hydrophilic polymer in the solution.

[0032] While conducting research to maximize the performance of a breathable waterproof film manufactured using a non-fluorinated polyolefin resin, the inventors recognized that when a hydrophilic polymer solution is applied to the surface of a polyolefin porous film, and the thickness, air permeability, porosity, and solid content ratio of the hydrophilic polymer solution are appropriately controlled, the film exhibits excellent breathability, waterproofness, and breathability, while also having low noise and excellent tactile feel upon friction, and at the same time, improved washing durability, and thus completed the present invention.

[0033] The above breathable waterproof film has excellent breathability and water permeability and breathability, and at the same time, produces little noise upon friction and has an excellent tactile feel, so it can provide a comfortable wearing experience when applied to items such as clothing, shoes, gloves, and hats, and has excellent washing durability, so it can maintain excellent breathability and water permeability even after washing.

[0034] The above (C*D) / (A*B) value may be 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, or a range between two of these values. If the (C*D) / (A*B) value is below the above range, the water pressure resistance or moisture permeability of the film may be low, making it unsuitable as a breathable waterproof film, and the tactile and noise characteristics of the film may be degraded; if it exceeds the above range, the water pressure resistance decreases significantly after washing, which may reduce washing durability.

[0035] The above polyolefin-based porous film may be formed from one polyolefin-based resin selected from the group consisting of polyethylene, polypropylene, polybutylene, polymethylpentene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations of two or more of these, but is not limited thereto.

[0036] The above polyolefin-based porous film may be formed from a polyolefin-based resin having a weight-average molecular weight of 350,000 to 450,000 g / mol. For example, the weight-average molecular weight of the above polyolefin-based resin may be 350,000 g / mol, 360,000 g / mol, 370,000 g / mol, 380,000 g / mol, 390,000 g / mol, 400,000 g / mol, 410,000 g / mol, 420,000 g / mol, 430,000 g / mol, 440,000 g / mol, 450,000 g / mol, or a range between two of these values. If the weight-average molecular weight of the polyolefin resin is below the above range, extrusion for sheet manufacturing may become difficult, and if it exceeds the above range, the tactile and noise characteristics of the film may deteriorate.

[0037] The term "weight-average molecular weight" as used in this specification refers to a value measured by gel permeation chromatography (GPC) using polystyrene as a standard sample according to the method described in the literature (Macromolecules, Vol. 34, No. 19, pp. 6812-6820 (2001) et al.).

[0038] The thickness of the above polyolefin-based porous film may be 5 to 100 μm. For example, it may be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, or a range between two of these values. If the thickness is less than the above range, the mechanical properties of the film may be excessively degraded or the breathability and water resistance may be reduced, and if it exceeds the above range, the softness of the film may be reduced or the noise characteristics during bending and / or friction may be reduced.

[0039] The thickness of the above polyolefin-based porous film can be measured using a micro-thickness measuring instrument.

[0040] The air permeability (Gurley) of the above polyolefin-based porous film may be 10 to 40 seconds / 100ml. For example, it may be 10 seconds / 100ml, 15 seconds / 100ml, 20 seconds / 100ml, 25 seconds / 100ml, 30 seconds / 100ml, 35 seconds / 100ml, 40 seconds / 100ml, or a range between two of these values. If the air permeability value exceeds the above range, the breathability of the film is reduced, and the wearing comfort may be reduced when applied to items such as clothing.

[0041] The term "Gurley" as used in this specification refers to the value obtained by measuring the time it takes for 100 ml of air to pass through a porous film specimen at a measuring pressure of 0.025 MPa using the Asahi Seiko Densometer EGO2-5 model.

[0042] The porosity of the above polyolefin-based porous film may be 60 to 90 volume%. For example, it may be 60 volume%, 65 volume%, 70 volume%, 75 volume%, 80 volume%, 85 volume%, 90 volume%, or a range between two of these values. If the porosity is below the above range, the moisture permeability and breathability of the film may be reduced, and if it exceeds the above range, mechanical properties including the tensile strength of the film may be excessively reduced.

[0043] The term "porosity" as used in this specification refers to a value measured using a PMI Capillary Porometer (CFP-1500AEL, wetting solution: Galwick) in accordance with ASTM F316-03.

[0044] The above hydrophilic polymer may be applied to one surface of the above polyolefin-based porous film.

[0045] The above hydrophilic polymer may be one selected from the group consisting of ethylene vinyl acetate, ethylene vinyl alcohol, polyvinyl alcohol, polyacrylic acid, polyoxyethylene-polyoxypropylene block copolymer, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl butyral, cellulose derivative, polyurethane, polyamide, polyester, glycerol, and combinations of two or more of these, but is not limited thereto.

[0046] The above solvent is water, NMP (N-Methyl-2-pyrrolidone), acetone, DMF (N,N-dimethylformamide), DMSO (Dimethyl sulfoxide), CHP (Cyclohexyl-pyrrolidone), N12P (N-dodecyl-pyrrolidone), benzyl benzoate, N8P (N-Octyl-pyrrolidone), DMEU (dimethyl-imidazolidinone), cyclohexanone, DMA (dimethylacetamide), NMF (N-Methyl Formamide), bromobenzene, chloroform, chlorobenzene, benzonitrile, quinoline, benzyl ether, ethanol, isopropyl alcohol, methanol, butanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, THF (tetrahydrofuran), ethylene glycol, pyridine, N-vinylpyrrolidone, It may be one selected from the group consisting of methyl ethyl ketone, alpha-terffinol, formic acid, ethyl acetate, acrylonitrile, toluene, and combinations of two or more of these, but is not limited thereto.

[0047] The solid content of the hydrophilic polymer in the above solution may be 15 to 35 wt%. For example, it may be 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, or a range between two of these values. If the solid content of the hydrophilic polymer in the solution is below the above range, the water pressure resistance or moisture permeability of the breathable waterproof film may decrease, and if it exceeds the above range, the waterproofness of the breathable waterproof film after washing may decrease significantly, which may reduce washing durability, and it may be difficult to manufacture a solution with a solid content of 40 weight% or more due to the clumping phenomenon of the hydrophilic polymer.

[0048] The water pressure resistance of the above breathable waterproof film, measured according to ATCC127, may be 9,000 to 20,000 mmH2O. For example, it may be 9,000 mmH2O, 10,000 mmH2O, 11,000 mmH2O, 12,000 mmH2O, 13,000 mmH2O, 14,000 mmH2O, 15,000 mmH2O, 16,000 mmH2O, 17,000 mmH2O, 18,000 mmH2O, 19,000 mmH2O, 20,000 mmH2O, or a range between two of these values. If the water pressure resistance is below the above range, the waterproofness of the film is insufficient and it may be unsuitable as a breathable waterproof film.

[0049] The moisture vapor transmission rate (MVTR) of the above breathable waterproof film, measured in accordance with DIN EN ISO 15496, is 5,000–20,000 g / m² 2 It can be / 24hr. For example, 5,000 g / m² 2 / 24hr, 6,000 g / m 2 / 24hr, 7,000 g / m 2 / 24hr, 8,000 g / m 2 / 24hr, 9,000 g / m 2 / 24hr, 10,000 g / m 2 / 24hr, 11,000 g / m 2 / 24hr, 2000 g / m 2 / 24hr, 13,000 g / m 2 / 24hr, 14,000 g / m 2 / 24hr, 15,000 g / m 2 / 24hr, 16,000 g / m 2 / 24hr, 17,000 g / m 2 / 24hr, 18,000 g / m 2 / 24hr, 19,000 g / m 2 / 24hr, 20,000 g / m 2It may be / 24hr or a range between the two of these values. If the moisture permeability is below the above range, the film may be unsuitable as a moisture-permeable waterproof film due to insufficient moisture permeability.

[0050] The above breathable waterproof film can maintain more than 90% of its waterproofness compared to before washing even after washing.

[0051] Laminated items

[0052] A laminate article according to another aspect of the present specification may comprise the above-described breathable waterproof film; and at least one layer bonded in contact with the breathable waterproof film.

[0053] The above laminated article includes a breathable waterproof film that has excellent breathability and water permeability and breathability, while also having low noise upon friction, excellent tactile feel, and excellent washing durability. When applied to items such as clothing, shoes, gloves, and hats, it can provide a comfortable wearing experience and maintain excellent breathability and water permeability even after washing.

[0054] The above layer may include one selected from the group consisting of a textile layer, a polymer film layer, a natural leather layer, a synthetic leather layer, a fleece layer, and a combination of two or more of these, but is not limited thereto.

[0055] The above laminate article may be a two-layer laminate comprising a textile layer adhered to at least one surface of the porous film. Additionally, the above laminate article may be a three-layer laminate comprising a first textile layer adhered to one surface of the porous film and a second textile layer adhered to the other surface. Furthermore, by laminating additional layers, a multilayer laminate having four, five, six, or more layers may be produced.

[0056] The textile layer may be formed from woven fabric, nonwoven fabric, knit, etc. The textile layer may be formed from natural and / or synthetic textiles, for example, cotton, wool, silk, jute, polyamide, polyester, acrylic, aramid, viscose, rayon, carbon fiber, or a combination thereof, but is not limited thereto.

[0057] The polymer film layer may be formed from, for example, polyolefin, polyester, polyamide, polyurethane, polyvinyl alcohol, polyvinyl acetate, fluoropolymer, polyvinyl halide, polyvinyl chloride, epoxy resin, silicone polymer, or a combination thereof, but is not limited thereto.

[0058] The embodiments of this specification will be described in more detail below. However, the following experimental results represent only representative results among the above embodiments, and the scope and content of this specification should not be interpreted as being narrowed or limited by the embodiments. The respective effects of various embodiments of this specification not explicitly presented below will be described in detail in the relevant sections.

[0059] Preparation Example 1

[0060] A polyurethane coating solution having a solid content of 10 wt% was prepared by mixing a polyurethane resin and water.

[0061] Preparation Example 2

[0062] A polyurethane coating solution having a solid content of 20 wt% was prepared by mixing a polyurethane resin and water.

[0063] Preparation Example 3

[0064] A polyurethane coating solution with a solid content of 32 wt% was prepared by mixing polyurethane resin and water.

[0065] Preparation Example 4

[0066] A polyurethane coating solution having a solid content of 37 wt% was prepared by mixing polyurethane resin and water.

[0067] Comparative Manufacturing Example 1

[0068] We attempted to manufacture a polyurethane coating solution with a solid content of 40% by weight by mixing polyurethane resin and water, but it was impossible to manufacture the coating solution due to the clumping of the polyurethane resin.

[0069] Example 1

[0070] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 2 above to one surface of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%.

[0071] Example 2

[0072] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 3 above to one surface of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%.

[0073] Comparative Example 1

[0074] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 1 above to one surface of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%.

[0075] Comparative Example 2

[0076] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 4 above to one surface of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%.

[0077] Comparative Example 3

[0078] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 1 above to one surface of a polyethylene porous film having a thickness of 5 μm, a Gurley air permeability of 85 s / 100 ml, and a porosity of 43.4 volume%.

[0079] Comparative Example 4

[0080] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 2 above to one surface of a polyethylene porous film having a thickness of 5 μm, a Gurley air permeability of 85 s / 100 ml, and a porosity of 43.4 volume%.

[0081] Comparative Example 5

[0082] A moisture-permeable waterproof film was prepared by applying the polyurethane coating solution prepared in Preparation Example 3 above to one side of a polyethylene porous film having a thickness of 5 μm, a Gurley air permeability of 85 s / 100 ml, and a porosity of 43.4 volume%.

[0083] The characteristics of the polyethylene porous film and polyurethane coating liquid used in the manufacture of the moisture-permeable waterproof film of the above examples and comparative examples were summarized, and the ratio ((C*D) / (A*B)) of the value obtained by multiplying the porosity (C) of the polyethylene porous film and the solid content (D) of the polyurethane coating liquid to the value obtained by multiplying the thickness (A) and air permeability (B) of the polyethylene porous film was calculated and shown in Table 1 below.

[0084] Classification Polyethylene porous film Polyurethane coating liquid Breathable waterproof film A: Thickness (μm) B: Air permeability (Gurley, sec / 100ml) C: Porosity (Volume%) D: Solid content (Weight%) (C*D) / (A*B) Example 1 182079.2204.40 Example 2 182079.2327.04 Comparative Example 1 182079.2102.20 Comparative Example 2 182079.2378.14 Comparative Example 3 58543.4101.02 Comparative Example 4 58543.4202.04 Comparative Example 5 58543.4323.27

[0085] The thickness, air permeability, and porosity of the above polyethylene porous film were measured by the following method. Unless otherwise noted regarding temperature, measurements were taken at room temperature (25 ℃). - Thickness (μm): The thickness of the porous film specimen was measured using a micro-thickness gauge.

[0086] - Air permeability (Gurley, seconds / 100ml): Using the Asahi Seiko Densometer EGO2-5 model, the time it takes for 100 ml of air to pass through a porous film specimen at a measurement pressure of 0.025 MPa was measured.

[0087] - Porosity (volume%): According to ASTM F316-03, the porosity of the porous film specimen was measured using a PMI Capillary Porometer (CFP-1500AEL, wetting solution: Galwick).

[0088] Experimental Example 1

[0089] To evaluate the breathability of the breathable waterproof films prepared in the above examples and comparative examples, their water pressure resistance and water permeability were measured.

[0090] For comparison, the water pressure resistance and moisture permeability of a polyethylene porous film without a polyurethane coating solution were measured together (Comparative Example 6: a polyethylene porous film with a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 vol%; Comparative Example 7: a polyethylene porous film with a thickness of 5 μm, a Gurley air permeability of 85 s / 100 ml, and a porosity of 43.4 vol%).

[0091] Water pressure and water vapor permeability were each measured at least four times using the following method, and the average of the measured values ​​was calculated. The results are shown in Table 2 below.

[0092] - Water pressure resistance (mmH2O): The water pressure resistance of the film specimen was measured according to ATCC127.

[0093] - Water vapor permeability (g / m²) 2 / 24hr): The moisture vapor transmission rate (MVTR) of the film specimen was measured according to DIN EN ISO 15496.

[0094] Classification Water Pressure Resistance (mmH2O) Water Permeability (g / m²) 2 / 24hr) Example 1 18,124 8,254 Example 2 20,000 7,564 Comparative Example 1 16,542 9,726 Comparative Example 2 20,000 6,322 Comparative Example 3 20,000 6,121 Comparative Example 4 20,000 6,658 Comparative Example 5 20,000 5,625 Comparative Example 6 15,841 10,786 Comparative Example 7 20,000 7,341

[0095] Referring to Table 2 above, it was confirmed that the breathable waterproof films of Examples 1 and 2 and Comparative Examples 1 to 5, which were prepared by applying a polyurethane coating solution to one side of a polyethylene porous film, had increased or maintained water pressure resistance and decreased water permeability compared to Comparative Examples 6 and 7, which were polyethylene porous films without a polyurethane coating solution.

[0096] The moisture-permeable waterproof films of Examples 1 and 2, which were coated with polyurethane coating solutions having solid content of 20 wt% and 32 wt% respectively on one side of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%, were evaluated to have excellent moisture-permeable waterproofness, as both water pressure resistance and moisture permeability values ​​were high.

[0097] The polyethylene porous film of Comparative Example 6 and the moisture-permeable waterproof film of Comparative Example 1, which had a polyurethane coating solution with a solid content of 10 wt% applied to one side of the same film, had low water pressure resistance and insufficient waterproofing, and the moisture-permeable waterproof film of Comparative Example 2, which had a polyurethane coating solution with a solid content of 37 wt% applied to one side of the same film, had low moisture permeability and insufficient moisture permeability.

[0098] It was confirmed that the polyethylene porous film of Comparative Example 7 and the moisture-permeable waterproof films of Comparative Examples 3 to 5, which had a polyurethane coating solution applied to one side of the same film, had low moisture permeability and insufficient moisture permeability.

[0099] Experimental Example 2

[0100] To evaluate the washing durability of the breathable waterproof films prepared in the above examples and comparative examples, their water pressure resistance and water vapor permeability were measured after washing.

[0101] For comparison, water pressure resistance and moisture permeability were measured after washing of a polyethylene porous film without a polyurethane coating solution applied (Comparative Example 6: a polyethylene porous film with a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 vol%; Comparative Example 7: a polyethylene porous film with a thickness of 5 μm, a Gurley air permeability of 85 s / 100 ml, and a porosity of 43.4 vol%).

[0102] The film was washed in lukewarm water at approximately 41°C for 12 minutes in accordance with AATCC 135, and the process of washing followed by spin-drying for 6 minutes was repeated 5 times. After drying, water pressure resistance and moisture permeability were measured in the same manner as in Experimental Example 1. In addition, the percentage of water pressure resistance after washing relative to the water pressure resistance before washing measured in Experimental Example 1 was calculated (Percentage of water pressure resistance after washing = (Water pressure resistance after washing / Water pressure resistance before washing) * 100). The results are shown in Table 3 below.

[0103] Classification Water pressure resistance after washing (mmH2O) Percentage of water pressure resistance after washing (%) Moisture permeability after washing (g / m²) 2 / 24hr) Example 1 17,102 948,564 Example 2 18,645 937,894 Comparative Example 1 16,542 100 9,365 Comparative Example 2 15,600 786,832 Comparative Example 3 16,841 847,865 Comparative Example 4 18,742 947,123 Comparative Example 5 19,520 986,548 Comparative Example 6 11,881 7511,245 Comparative Example 7 14,200 717,953

[0104] Referring to Table 3 above, the water pressure resistance decreased after washing compared to before washing, and the moisture permeability showed a tendency to increase after washing.

[0105] The breathable waterproof films of Examples 1 and 2, which were coated with polyurethane coating solutions having solid content of 20 wt% and 32 wt% respectively on one side of a polyethylene porous film having a thickness of 18 μm, a Gurley air permeability of 20 s / 100 ml, and a porosity of 79.2 volume%, were evaluated to have excellent washing durability, with high water pressure resistance and water vapor permeability values ​​after washing and a low rate of water pressure reduction after washing.

[0106] The polyethylene porous film of Comparative Example 6 and the breathable waterproof film of Comparative Example 2, which had a polyurethane coating solution with a solid content of 37 wt% applied to one side of the same film, showed a decrease in water pressure resistance of 20% or more after washing compared to before washing, indicating a significant decrease in waterproofness after washing. The breathable waterproof film of Comparative Example 1, which had a polyurethane coating solution with a solid content of 10 wt% applied to one side of the same film, was evaluated as having low water pressure resistance before washing and insufficient waterproofness even after washing.

[0107] The polyethylene porous film of Comparative Example 7 showed a 29% decrease in water pressure resistance after washing compared to before washing, indicating a significant deterioration in water resistance after washing. Similarly, the breathable waterproof film of Comparative Example 3, which had a polyurethane coating solution with a solid content of 10 wt% applied to one side of the same film, also showed a 16% decrease in water pressure resistance after washing compared to before washing. Furthermore, the breathable waterproof films of Comparative Examples 4 and 5, which had polyurethane coating solutions with solid content of 20 wt% and 32 wt% applied to one side of the same film, respectively, were evaluated as having low water permeability before washing and insufficient water permeability even after washing.

[0108] Experimental Example 3

[0109] The noise characteristics upon friction of the breathable waterproof films prepared in the above examples and comparative examples were evaluated in the following manner. The results are shown in Table 4 below.

[0110] - Noise Characteristics (dB): In a space equipped with a sound barrier, breathable waterproof film specimens measuring 20 cm x 30 cm were folded in half and overlapped (10 cm x 30 cm). The noise levels were measured using the TES-1350A noise measuring device while holding the specimens at 10 cm intervals and moving them vertically. The distance between the specimen and the noise measuring device was set to 10 cm, and measurements were recorded at 5-second intervals for 30 seconds. The noise level was measured five times for each specimen, and the minimum (Min), maximum (Max), and average (Ave) values ​​of each measurement were evaluated. For comparison, the baseline noise of the space where the noise measurements were performed was additionally measured.

[0111] Classification Minimum Value (Min) Maximum Value (Max) Average Value (Ave) Example 1 46.5 58.6 52.4 Example 2 45.9 56.9 51.2 Comparative Example 4 62.5 67.5 64.1 Comparative Example 5 64.2 70.2 67.2 Basic Noise 36.6 39.1 37.8

[0112] Referring to Table 4 above, it was confirmed that the breathable waterproof film specimens prepared in Examples 1 and 2 produced less noise upon friction compared to the breathable waterproof film specimens prepared in Comparative Examples 4 and 5. This difference in noise magnitude was perceptible even to the human ear.

[0113] In addition, the breathable waterproof film specimen prepared in the example was evaluated to have a superior tactile feel compared to the breathable waterproof film specimen prepared in the comparative example.

[0114] The foregoing description of this specification is for illustrative purposes only, and those skilled in the art to which one aspect of this specification pertains will understand that other specific forms can be easily modified without altering the technical concept or essential features described in this specification. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0115] The scope of this specification is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of this specification.

Claims

1. Polyolefin-based porous film; and A hydrophilic polymer applied to the surface of the polyolefin-based porous film by a solution comprising a hydrophilic polymer and a solvent; comprising A breathable waterproof film satisfying the following formula: <Food> 4 ≤ (C*D) / (A*B) ≤ 8 In the above formula, A is the thickness (μm) of the above polyolefin-based porous film, and B is the air permeability (Gurley, seconds / 100ml) of the above polyolefin-based porous film, and C is the porosity (volume%) of the above polyolefin-based porous film, and D is the solid content (weight%) of the hydrophilic polymer in the above solution.

2. In Paragraph 1, The above-mentioned polyolefin-based porous film is a breathable waterproof film formed from a polyolefin-based resin selected from the group consisting of polyethylene, polypropylene, polybutylene, polymethylpentene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations of two or more of these.

3. In Paragraph 1, A moisture-permeable waterproof film having a thickness of 5 to 100 μm of the above polyolefin-based porous film.

4. In Paragraph 1, A moisture-permeable waterproof film having a Gurley air permeability of 10 to 40 seconds / 100ml of the above polyolefin-based porous film.

5. In Paragraph 1, A moisture-permeable waterproof film having a porosity of 60 to 90 volume% of the above polyolefin-based porous film.

6. In Paragraph 1, The above-mentioned hydrophilic polymer is one selected from the group consisting of ethylene vinyl acetate, ethylene vinyl alcohol, polyvinyl alcohol, polyacrylic acid, polyoxyethylene-polyoxypropylene block copolymer, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl butyral, cellulose derivative, polyurethane, polyamide, polyester, glycerol, and combinations of two or more of these, a breathable waterproof film.

7. In Paragraph 1, The above solvent is water, NMP (N-Methyl-2-pyrrolidone), acetone, DMF (N,N-dimethylformamide), DMSO (Dimethyl sulfoxide), CHP (Cyclohexyl-pyrrolidone), N12P (N-dodecyl-pyrrolidone), benzyl benzoate, N8P (N-Octyl-pyrrolidone), DMEU (dimethyl-imidazolidinone), cyclohexanone, DMA (dimethylacetamide), NMF (N-Methyl Formamide), bromobenzene, chloroform, chlorobenzene, benzonitrile, quinoline, benzyl ether, ethanol, isopropyl alcohol, methanol, butanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, THF (tetrahydrofuran), ethylene glycol, pyridine, N-vinylpyrrolidone, A breathable waterproof film selected from the group consisting of methyl ethyl ketone, alpha-terffinol, formic acid, ethyl acetate, acrylonitrile, toluene, and combinations of two or more of these.

8. In Paragraph 1, A breathable waterproof film having a solid content of the hydrophilic polymer in the above solution of 15 to 35 weight%.

9. In Paragraph 1, A breathable waterproof film having a water pressure resistance of 9,000 to 20,000 mmH2O as measured according to ATCC127.

10. In Paragraph 1, The water vapor transmission rate (MVTR) of the above breathable waterproof film, measured in accordance with DIN EN ISO 15496, is 5,000–20,000 g / m² 2 24hr breathable waterproof film.

11. The breathable waterproof film of paragraph 1; and A laminated article comprising at least one layer bonded in contact with the above-mentioned breathable waterproof film.

12. In Paragraph 11, The above layer comprises one selected from the group consisting of a textile layer, a polymer film layer, a natural leather layer, a synthetic leather layer, a fleece layer, and a combination of two or more of these, a laminated article.