Waterproof, breathable and moisture-permeable polyurethane composite fabric

Abstract

The utility model provides a waterproof, breathable and moisture-permeable polyurethane composite fabric, characterized by comprising, from bottom to top, a moisture-absorbing base layer, a mutual micro-porous layer and a waterproof and breathable layer, which are sequentially laminated and bonded; the moisture-absorbing base layer comprises a base cloth and a hydrophilic polyurethane resin impregnated in the base cloth; the mutual micro-porous layer comprises a polyester-polyether type polyurethane resin with a plurality of micro-holes of 0.5-5 microns in diameter uniformly distributed and interconnected inside; and the waterproof and breathable layer is a polyester type polyurethane resin. The utility model improves the breathability and moisture permeability of the base cloth by impregnating the base cloth with ethylene glycol-modified polyurethane resin. A mutual micro-porous layer with high-speed air exchange is formed on the surface of the base cloth by coating and drying foamed polyurethane resin on the surface of the base cloth. Finally, a dense high-molecular waterproof and breathable layer is formed on the surface, which improves the waterproofness and physical strength of the composite material, and thus has good surface waterproofness, upper and lower moisture-permeable and breathable performance, and is suitable for sports shoes, casual shoes, outdoor shoes and the like.

Description

Technical Field

[0001] This utility model belongs to the field of synthetic leather technology, specifically relating to a waterproof, breathable and moisture-permeable polyurethane composite fabric. Background Technology

[0002] In the current synthetic leather manufacturing field, the production of dry polyurethane films still commonly employs release paper transfer technology. The core step of this process involves coating the prepared polyurethane slurry onto the surface of release paper, drying and curing it into a film in an oven tunnel, and then transferring and bonding it to the base fabric. However, this mainstream process suffers from several significant technical bottlenecks:

[0003] I. Cost and Efficiency Constraints: As a core disposable consumable, release paper requires frequent replacements. This, coupled with the long-term reliance on imports for high-end products, results in a significantly higher per-square-meter production cost for dry lamination compared to wet lamination. Furthermore, the complexity of the multi-layer lamination process severely restricts equipment turnover efficiency and reduces overall production effectiveness.

[0004] II. Microporous Structure and Functional Defects: More critically, during the film forming process, the physical barrier effect of the release paper restricts the solvent swelling process of the surface polyurethane. This inhibition directly hinders the development of the microporous structure within the leather, making it difficult to form a complete and interconnected three-dimensional network. As a result, the key functional indicators of the finished synthetic leather, such as air permeability and moisture permeability, fail to meet the requirements of high-performance applications.

[0005] Meanwhile, the global outdoor sports market is showing a trend towards diversification and all-weather development. The popularity of activities such as hiking, mountaineering, and cycling has placed unprecedentedly stringent demands on the environmental adaptability of footwear leather materials. High-performance footwear materials must achieve excellent breathability and moisture permeability while ensuring effective waterproofing, presenting a comprehensive technical challenge. The global athletic footwear market continues to grow, and leading brands are increasingly focusing their competition on functional innovation. Against this backdrop, synthetic leather with superior waterproof, breathable, and moisture-permeable properties has become a core technological barrier and a significant source of value for high-end outdoor footwear and professional athletic shoes, resulting in significant market premiums for related products.

[0006] In summary, existing synthetic leather produced using release paper transfer technology only meets basic outdoor needs in terms of functionality (especially breathability and moisture permeability). Facing the growing market for high-performance footwear materials, its performance limitations are becoming increasingly apparent. Therefore, there is an urgent need for fundamental technological innovation to overcome the limitations of existing technologies and develop a new generation of synthetic leather manufacturing technology that combines excellent waterproofing, high breathability, and high moisture permeability to meet the pressing needs of the high-end market. Utility Model Content

[0007] Therefore, the purpose of this utility model is to address the above-mentioned shortcomings by providing a polyurethane composite fabric with waterproof, breathable, and moisture-permeable properties that does not rely on release paper transfer process.

[0008] like Figure 1 As shown, this embodiment of the invention provides a waterproof, breathable, and moisture-permeable polyurethane composite fabric, characterized in that it comprises layers stacked and joined sequentially from bottom to top:

[0009] The moisture-absorbing base layer (1) is composed of a base fabric and a hydrophilic polyurethane resin impregnated in the base fabric;

[0010] Interconnected microporous layer (2) comprises polyester polyether type polyurethane resin, which has uniformly distributed and interconnected micropores inside, the average pore size of the micropores being 0.5-5μm;

[0011] Waterproof and breathable layer (3), which contains polyester polyurethane resin.

[0012] This invention relates to a substrate with high breathability and moisture permeability obtained by impregnating a base fabric with glycol-modified polyurethane resin. Simultaneously, a foamed polyurethane resin is coated onto the surface of the polyurethane moisture-absorbing base layer using a direct coating process, and after drying, a layer of interconnected microporous layers with high-speed air exchange is formed. Finally, a dense polyurethane waterproof and breathable layer is transferred to the surface, simultaneously improving the waterproofness and physical strength of the composite fabric. This invention features excellent surface waterproofing and top and bottom moisture permeability, making it suitable for sports shoes, casual shoes, and outdoor shoes.

[0013] According to the waterproof, breathable, and moisture-permeable polyurethane composite fabric provided by this embodiment, the thickness of the moisture-absorbing base layer 1 can be 0.6-1.2 mm; the thickness of the interconnected microporous layer 2 can be 0.1-0.5 mm; and the thickness of the waterproof and breathable layer 3 can be 0.01-0.3 mm.

[0014] According to this embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric is used, wherein the lower surface of the interconnected microporous layer 2 is directly bonded to the upper surface of the moisture-absorbing base layer 1, and the two surfaces have matching contours and are seamlessly bonded and fixed.

[0015] This invention employs a dry direct coating process to directly coat a slurry containing polyester polyether polyurethane onto a substrate layer, which is then dried and shaped to form a structure in which two layers of material are physically adjacent and have no other transition layer in between. This avoids gaps or delamination between the layers and facilitates the control of the thickness of the interconnected microporous layer.

[0016] According to the present embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric is used, wherein the lower surface of the waterproof and breathable layer 3 is directly bonded to the upper surface of the interconnected microporous layer 2, and the two surfaces have matching contours and are seamlessly bonded and fixed.

[0017] This invention uses a printing process to transfer a paste containing polyester polyurethane resin to the surface of an interconnected microporous layer, and then cures it to form a structure in which two layers of material are physically adjacent and there is no other transition layer in between. This avoids gaps or delamination between the layers and facilitates the formation of an ultra-thin waterproof and breathable layer.

[0018] The waterproof and breathable layer is made of water-based polyurethane resin. The use of a fluorine-free waterproofing agent achieves waterproofing and breathability while avoiding the environmental damage caused by fluorine compounds. The production process uses solvent-free resin slurry, making the processing more environmentally friendly. Preferably, the porosity of the interconnected microporous layer 2 is 40%-60%. Preferably, the pore connectivity of the interconnected microporous layer 2 is greater than 90%.

[0019] According to this embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric is used, wherein the density of the waterproof and breathable layer 3 is greater than that of the polyurethane moisture-absorbing base layer 1, and the density of the polyurethane moisture-absorbing base layer 1 is greater than that of the interconnected microporous layer 2.

[0020] According to this embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric is disclosed, wherein the base fabric can be woven, knitted, or non-woven. Its material can be polyester fiber and / or nylon fiber. During the preparation process, the base fabric is impregnated with ethylene glycol-modified polyurethane resin to obtain a hydrophilic group-modified substrate, thereby imparting moisture-absorbing properties to the substrate. In some exemplary embodiments of this invention, the hydrophilic group-modified polyurethane can be selected from SW-5025 of Hefei Anli Polyurethane New Materials Co., Ltd.

[0021] According to this embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric is available, wherein the weight of the polyurethane composite fabric can be 210-280 g / m². 2 The preferred value is 220-240 g / m³. 2 .

[0022] According to this embodiment, a novel waterproof, breathable, and moisture-permeable polyurethane composite fabric has a waterproof water pressure resistance of up to 100 cm H2O and a breathability of 200-300 cm. 3 / cm 2 / s (internal and external pressure difference 125Pa), moisture permeability can reach 13-20 mg / (cm²) 2 (⋅h). This embodiment uses a novel polyurethane composite fabric that achieves a balance between waterproofing, breathability, and moisture permeability through structural and coating design.

[0023] In a preferred embodiment of this invention, the waterproof and breathable layer is prepared from a mixture containing the following components in parts by weight:

[0024] 50-160 parts of polyester polyurethane resin,

[0025] 3-10 parts of curing agent

[0026] Leveling agent 0.3-3 parts

[0027] Defoamer 0.1-1 part

[0028] 0.3-5 parts of alkali-swellable thickener

[0029] 1-8 parts of fluoride-free water repellent

[0030] 5-20 parts pigment.

[0031] In a preferred embodiment of this invention, the interconnected microporous layer is prepared from the following components in parts by weight:

[0032] 120-200 parts of polyester polyether polyurethane

[0033] 80-300 parts of curing agent

[0034] 1-10 parts of foaming agent

[0035] 0.1-1 part of silicone leveling agent,

[0036] 10-30 parts pigment.

[0037] In a preferred embodiment of this invention, the interconnected microporous layer 2 forms micropores through the thermal activation of a foaming agent. The foaming agent can be thermoplastic hollow polymer microspheres (commonly known as foaming powder), whose structure consists of a thermoplastic acrylic resin polymer shell and encapsulated alkane gas inside. When heated to the activation temperature, the gas pressure inside the microspheres increases, the polymer shell softens and expands, and the volume increases rapidly to 3-5 times its original size. After continuous heating to the shell rupture threshold, the alkane gas is released and forms uniformly distributed interconnected channels in the polymer matrix. After curing and shaping, a three-dimensional interconnected network structure with an average pore size of 0.5-5 μm and a pore connectivity rate >90% is finally formed within the interconnected microporous layer 2. This structure provides a directional diffusion path for water vapor molecules while blocking liquid water penetration, forming the core structural basis for achieving the fabric's breathable, moisture-wicking, and waterproof functions. The foaming agent / foaming powder can be commercially available, for example, EHL101 and EMH204 microsphere foaming powders from Sekisui Chemicals of Japan, TX series microsphere foaming powders from Dongguan Hongfu Chemical, or Hydrocerol foaming powder from Shenzhen Sude Trading.

[0038] It should be noted that the core innovation of this utility model lies in the structural design of the multi-layer composite structure, rather than the selection of materials themselves. The resins, additives, and other components used in the moisture-absorbing base layer 1, the interconnected microporous layer 2, and the waterproof and breathable layer 3 are all conventional materials known in the art, and this utility model does not specifically limit their types. The preferred formulation provided above is merely one feasible implementation method for achieving this composite structure and is not intended to limit the scope of protection of this utility model.

[0039] This invention improves the breathability and moisture permeability of a base fabric by impregnating it with ethylene glycol-modified polyurethane resin. Simultaneously, a direct coating process is used to coat the base fabric surface with foamed polyurethane resin, which, after drying, forms a layer of interconnected microporous layers with high-speed air exchange. Finally, a dense polymer waterproof and breathable layer is transferred to the surface, simultaneously improving the waterproofness and physical strength of the composite material. The polyurethane composite fabric provided by this invention possesses waterproof, breathable, and moisture-permeable properties. Its waterproof resistance to water pressure can reach 100 cm H2O, and its breathability is 200-300 cm under an internal and external pressure difference of 125 Pa. 3 / (cm 2 ·s), moisture permeability can reach 13-20 mg / (cm³). 2 (h). This fabric utilizes an integrated design to form a three-dimensional functional architecture consisting of a "surface hydrophobic molecular barrier - a middle interconnected porous network - a bottom affinity conductive layer," achieving a balance between surface waterproofing and the bidirectional dynamic transmission of internal gas and liquid molecules. Based on this waterproof, breathable, and moisture-permeable technology, the product is suitable for various footwear applications, including athletic shoes, urban casual shoes, and professional outdoor shoes, providing wearers with an intelligent microclimate regulation experience in all weather conditions. Attached Figure Description

[0040] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings, wherein:

[0041] Figure 1 This is a cross-sectional schematic diagram of the waterproof, breathable, and moisture-permeable polyurethane composite fabric provided by this utility model, which includes: 1-polyurethane moisture-absorbing base layer, 2-interconnected microporous layer and 3-waterproof and breathable layer. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0044] The waterborne polyurethane resins KTT736A, KTT7200, KTA708, and KT703G used in the following examples are products of Hefei Ketian Waterborne Technology Co., Ltd.

[0045] In some embodiments provided by this utility model, the preparation method of the waterproof, breathable, and moisture-permeable polyurethane composite fabric may include:

[0046] (1) The base fabric is impregnated in a polyurethane impregnation solution modified with hydrophilic groups and dried to form a moisture-absorbing base layer;

[0047] (2) The interconnected microporous layer slurry containing polyester polyether polyurethane resin is coated onto the surface of the moisture-absorbing substrate obtained in step (1) by a dry direct coating process, and foamed under a gradient temperature of 80-130℃ to form an interconnected microporous layer.

[0048] (3) The waterproof and breathable layer slurry containing polyester polyurethane resin is transferred to the surface of the interconnected microporous layer obtained in step (2) by printing process and cured at 100-150℃ to form a waterproof and breathable layer.

[0049] The solid content of the impregnation liquid in step (1) can be 18%-30%, preferably 20%-25%.

[0050] In step (2), the interconnected microporous layer is directly coated onto the substrate using a dry direct coating process, resulting in higher production efficiency and a simpler processing method. The dry direct coating process is repeated 1-3 times.

[0051] Preferably, in the printing process described in step (3), the paste transfer thickness is relatively thin, generally 0.005mm-0.05mm. In the printing process, the printing roller can be selected from various aspects based on the required feel, gloss, color, etc., and the texture depth should generally not be too deep. In the preferred embodiment of this utility model, the texture depth of the printing roller is 20-50 μm.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. This invention provides a polyurethane composite material product with waterproof, breathable, and moisture-permeable properties. The process involves impregnating a base fabric with ethylene glycol-modified polyurethane resin to obtain a substrate with high breathability and moisture permeability. Simultaneously, a foamed polyurethane resin is coated onto the base fabric surface using a direct coating process, and after drying, a layer of interconnected microporous layers with high-speed air exchange is formed. Finally, a dense polymer waterproof and breathable layer is transferred to the surface, simultaneously improving the waterproofness and physical strength of the composite material. This invention exhibits excellent surface waterproofing and top and bottom moisture permeability, making it suitable for sports shoes, casual shoes, outdoor shoes, etc.

[0054] 2. The polyurethane composite material product with waterproof, breathable and moisture-permeable properties prepared by this utility model adopts a dry direct coating process, which solves the problems of poor air and moisture permeability in products prepared by the release paper transfer method in traditional processes, ensuring that the product has excellent air and moisture permeability, and also has higher production efficiency and simpler production process adjustment.

[0055] 3. The polyurethane composite material product with waterproof, breathable and moisture-permeable properties prepared by this utility model adopts a printing process. There are no organic solvents in the production process, the production process is energy-saving and environmentally friendly, and the product has low VOC. It is an ideal environmentally friendly leather material for sports and leisure shoes.

[0056] Example 1

[0057] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Materials Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of approximately 85%.

[0058] A resin slurry was prepared by mixing 180 parts of KTT7200, 8 parts of curing agent, 5 parts of foaming agent, 1 part of silicone leveling agent, and 20 parts of pigment. The slurry was then directly coated onto the substrate using a dry direct coating process to form an interconnected microporous layer with a coating thickness of 0.5 mm. The interconnected microporous layer was then dried and set at 130°C and rolled up.

[0059] A waterproof and breathable layer slurry (120 parts KTT736A, 5 parts curing agent, 0.5 parts leveling agent, 0.3 parts defoamer, 0.5 parts alkali-swellable thickener, 5 parts fluorine-free water-repellent agent, and 15 parts pigment) was prepared according to the specified ratio. The slurry was then transferred to the surface of the interconnected microporous layer through a printing process and cured at 150°C to form a waterproof and breathable layer with a thickness of 1.0 mm.

[0060] A polyurethane composite fabric with waterproof, breathable, and moisture-permeable properties was obtained.

[0061] Example 2

[0062] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Materials Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of approximately 80%.

[0063] A resin slurry was prepared by mixing 180 parts of KTT7200, 8 parts of curing agent, 5 parts of foaming agent, 1 part of silicone leveling agent, and 20 parts of pigment. The slurry was then directly coated onto the substrate using a dry direct coating process to form an interconnected microporous layer with a coating thickness of 0.1 mm. The interconnected microporous layer was dried and set at 130°C and then wound up.

[0064] A waterproof and breathable layer slurry (150 parts KT703G, 7 parts curing agent, 0.5 parts leveling agent, 0.3 parts defoamer, 0.8 parts alkali-swelling thickener, 5 parts fluorine-free water-repellent agent, and 20 parts pigment) was prepared according to the specified ratio. The slurry was then transferred to the surface of the interconnected microporous layer through a printing process and cured at 150℃ to form a waterproof and breathable layer with a thickness of 1.0 mm.

[0065] A polyurethane composite fabric with waterproof, breathable, and moisture-permeable properties was obtained.

[0066] Example 3

[0067] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Materials Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of approximately 90%.

[0068] A resin slurry was prepared by mixing 150 parts of KTA708, 6 parts of curing agent, 5 parts of foaming agent, 1 part of silicone leveling agent, and 15 parts of pigment. The slurry was then directly coated onto the substrate using a dry direct coating process to form an interconnected microporous layer with a coating thickness of 0.5 mm. The interconnected microporous layer was dried and set at 130°C and then wound up.

[0069] A waterproof and breathable layer slurry (150 parts KT703G, 7 parts curing agent, 0.5 parts leveling agent, 0.3 parts defoamer, 0.8 parts alkali-swelling thickener, 5 parts fluorine-free water-repellent agent, and 20 parts pigment) was prepared according to the specified ratio. The slurry was then transferred to the surface of the interconnected microporous layer through a printing process and cured at 150℃ to form a waterproof and breathable layer with a thickness of 1.2 mm.

[0070] A polyurethane composite fabric with waterproof, breathable, and moisture-permeable properties was obtained.

[0071] Example 4

[0072] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Material Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of 85%.

[0073] A resin slurry was prepared by mixing 150 parts of KTA708, 6 parts of curing agent, 1 part of silicone leveling agent, and 15 parts of pigment. The slurry was then directly coated onto the substrate using a dry direct coating process to form an interconnected microporous layer with a coating thickness of 0.2 mm. The interconnected microporous layer was then dried and set at 130°C and rolled up.

[0074] A waterproof and breathable layer slurry (120 parts KTT736A, 5 parts curing agent, 0.5 parts leveling agent, 0.3 parts defoamer, 0.5 parts alkali-swellable thickener, 5 parts fluorine-free water-repellent agent, and 15 parts pigment) was prepared according to the specified ratio. The slurry was then transferred to the surface of the interconnected microporous layer through a printing process and cured at 150℃ to form a waterproof and breathable layer with a thickness of 1.2 mm.

[0075] A polyurethane composite fabric with waterproof, breathable, and moisture-permeable properties was obtained.

[0076] Comparative Example 1

[0077] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Material Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of 85%.

[0078] A resin slurry was prepared by mixing 180 parts of KTT7200, 8 parts of curing agent, 5 parts of foaming powder, 1 part of silicone leveling agent, and 20 parts of pigment. The slurry was then directly coated onto the substrate using a dry direct coating process to form an interconnected microporous layer with a coating thickness of 0.5 mm. The interconnected microporous layer was dried and set at 130°C and then wound up to obtain a polyurethane composite fabric for comparison with Example 1.

[0079] Comparative Example 2

[0080] A 1.0mm nylon nonwoven fabric (Anhui Hongyuan Co., Ltd.) was impregnated with ethylene glycol-modified polyurethane resin (SW-5025, Hefei Anli New Material Polyurethane Co., Ltd.) to obtain a modified substrate containing hydrophilic groups, with a wet slurry impregnation rate of 85%.

[0081] A waterproof and breathable layer slurry (150 parts KT703G, 7 parts curing agent, 0.5 parts leveling agent, 0.3 parts defoamer, 0.8 parts alkali-swellable thickener, 5 parts fluorine-free water-repellent agent, and 20 parts pigment) was prepared according to the specified ratio. The slurry was transferred to the surface of a polyurethane moisture-absorbing base layer using a printing process and cured at 150°C to form a 1.2 mm thick waterproof and breathable layer. A polyurethane composite fabric was thus prepared for comparison with Example 1.

[0082] Characterization and testing methods

[0083] I. Appearance Testing

[0084] Under natural light, observe the material surface from a vertical perspective at a distance of 30-50 cm from the sample, and evaluate the appearance quality of the material surface (such as whether it is transparent, uniformity, defects, etc.).

[0085] Judgment criteria:

[0086] Normal: The surface is free of defects such as transparent bottom, cracks, bubbles, and impurities;

[0087] Transparent: The color or texture of the substrate is clearly visible through the surface (as in Comparative Example 2).

[0088] II. Morphological Characterization

[0089] The cross-section morphology of the composite fabric prepared in Example 1 was observed using a scanning electron microscope (SEM): the sample was placed in liquid nitrogen for brittle fracture and then sputtered with gold; the cross-sectional structure was observed under an accelerating voltage of 5 kV.

[0090] III. Peel Strength Test (Unit: N / 3cm)

[0091] Referring to ASTM D3359, "Test Method for Peel Adhesion of Adhesive Tapes", the test material was bonded to a standard substrate (stainless steel plate) to form a 3 cm wide specimen with a 10 cm bond length. After standing for 24 hours, peeling was performed at a peel angle of 180° and a tensile speed of 300 mm / min. The force values ​​during the peeling process were recorded using an electronic universal testing machine, and the average value was taken as the peel strength.

[0092] IV. Waterproof and water pressure resistance test (unit: cm H2O)

[0093] Referring to GB / T 4744 "Water Resistance Test for Textiles - Hydrostatic Pressure Test", cut a 5cm × 5cm sample and fix it on the sample holder of the testing device. Gradually increase the water pressure at a rate of 10 cm H2O / min, and maintain the target water pressure at 100 cm H2O for 30 minutes. Observe whether water seepage occurs on the sample surface. If there is no water seepage within 30 minutes, the water pressure resistance meets the standard; if water seepage occurs, the water pressure resistance is 0 (as in Comparative Example 1).

[0094] V. Air permeability test (unit: cm) 3 / cm 2 / s)

[0095] The air permeability test was conducted according to the standard GB / T5453-1997, "Test Method for Air Permeability of Nonwoven Fabrics in Textiles." Samples of uniform thickness were selected and placed flat in the test area of ​​the fabric air permeability tester to determine the fabric air permeability rate. The pressure difference was set at 10 kPa, and the effective test area was 20 cm². 2 For each sample, the experiment was repeated more than 10 times at different locations, and the average value was taken.

[0096] VI. Moisture permeability test (unit: mg / (cm²・h))

[0097] The moisture permeability test was conducted according to standard GB / T 12704.1-2009 Textiles / Fabrics - Test Method for Moisture Permeability - Part 1: Moisture Absorption Method. The equipment was conditioned, and a 70mm diameter sample was cut, weighed, and placed with the test surface facing upwards on the moisture permeability cup. A gasket and pressure ring were installed, and the nut was screwed on. The pressure ring, gasket, and moisture permeability cup were then sealed from the side with vinyl tape to form the test assembly. The assembly was placed in the conditioned test chamber and, after a certain equilibration time, removed and weighed. The difference in mass between the two weighings was recorded as Δm. By measuring the difference in mass between the two weighings of the blank group (the moisture permeability of the moisture permeability cup without a sample) Δm′, the interference of ambient humidity and the device's own water vapor transmission on the results was eliminated. (Δm - Δm′) represents the actual mass difference of water vapor permeating from the sample.

[0098] The moisture permeability WVT (unit: g / (m³)) is calculated using the following formula. 2 ·h)):

[0099]

[0100] Where A is the effective moisture permeability area of ​​the sample (m²) 2 ), where t is the test time (h).

[0101] Characterization and test results

[0102] I. Scanning electron microscopy (SEM) results show that the sample in Example 1 has the following morphological characteristics:

[0103] (1) There is no visible gap at the interface between the interconnected microporous layer 2 and the moisture-absorbing substrate layer 1. The lower surface of the microporous layer is embedded in the concave-convex structure of the upper surface of the substrate layer, presenting a mechanically interlocked form.

[0104] (2) The interface between the waterproof and breathable layer 3 and the interconnected microporous layer 2 is in a continuous transition state, without delamination or cracks.

[0105] (3) Interconnected microporous layer structure: The micropores are distributed in a three-dimensional interconnected network with an average pore diameter of 2±0.5μm; the pore wall thickness is uniform and the porosity is about 55%; the micropore interconnection path is clear and the connectivity rate is >90%.

[0106] (4) Hygroscopic base layer impregnation state: The hydrophilic polyurethane resin completely covers the base fabric fibers, and the gaps between the fibers are filled by the resin to form a dense structure.

[0107] II. The results of performance tests on the polyurethane composite fabrics prepared in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1 below.

[0108] Table 1

[0109]

[0110] Testing revealed that the waterproof and breathable layer of this invention plays a crucial role in the waterproof and water pressure-resistant performance of polyurethane composite fabric products, while the interconnected microporous layer forms the main body of the product's surface color. Furthermore, the thickness of the interconnected microporous layer negatively impacts breathability and moisture permeability; that is, the greater the thickness, the worse the breathability and moisture permeability. Through the interaction of the waterproof and breathable layer, the interconnected microporous layer, and the moisture-permeable base layer, the material's waterproof, breathable, and moisture-permeable properties are ensured. While meeting the physical strength requirements of traditional sports and leisure shoe leather, it achieves a combination of waterproof, breathable, and moisture-permeable properties, thus enhancing the product's competitive advantage in the market.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A waterproof, breathable, and moisture-permeable polyurethane composite fabric, characterized in that, Including those that are stacked and joined from bottom to top: The moisture-absorbing base layer (1) has a thickness of 0.6-1.2 mm and is composed of a base fabric and a hydrophilic polyurethane resin impregnated in the base fabric; Interconnected microporous layer (2), with a thickness of 0.1-0.5 mm, contains polyester polyether type polyurethane resin, and has uniformly distributed and interconnected micropores inside, the average pore size of the micropores being 0.5-5 μm; A waterproof and breathable layer (3), with a thickness of 0.01-0.3 mm, comprises polyester-type polyurethane resin. The lower surface of the interconnected microporous layer (2) is directly bonded to the upper surface of the moisture-absorbing base layer (1), and the two surfaces are matched in contour and seamlessly bonded together. The lower surface of the waterproof and breathable layer (3) is directly bonded to the upper surface of the interconnected microporous layer (2), and the two surfaces are matched in contour and seamlessly bonded and fixed.

2. The polyurethane composite fabric according to claim 1, characterized in that, The density of the waterproof and breathable layer (3) is greater than that of the moisture-absorbing base layer (1), and the density of the moisture-absorbing base layer (1) is greater than that of the interconnected microporous layer (2).

3. The polyurethane composite fabric according to claim 1, characterized in that, The base fabric is woven fabric, knitted fabric, or nonwoven fabric.

4. The polyurethane composite fabric according to claim 1, characterized in that, The porosity of the interconnected microporous layer (2) is 40%-60%.

5. The polyurethane composite fabric according to claim 1, characterized in that, The pore connectivity of the interconnected microporous layer is greater than 90%.

6. The polyurethane composite fabric according to any one of claims 1 to 5, characterized in that, The polyurethane composite fabric has a basis weight of 210-280 g / m². 2 .

7. The polyurethane composite fabric according to claim 6, characterized in that, The polyurethane composite fabric has a basis weight of 220-240 g / m². 2 .

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