A waterproof and breathable roll material

Abstract

This invention discloses a waterproof and breathable roll material, belonging to the field of waterproof roll material technology. The roll material is a four-layer structure formed by combining a ZnO@PU / PVDF nanofiber membrane, a fiberglass base fabric, and a waterproof TPO material. The fiberglass base fabric, as the reinforcing fiber layer, possesses good mechanical properties. Polypropylene resin, calcium carbonate, TPO resin, and polyethylene resin are melt-extruded and calendered with the fiberglass base fabric to form a two-layer structure. Based on this, the ZnO@PU / PVDF nanofiber membrane is electrospun and hot-pressed to prepare the four-layer waterproof and breathable roll material. Nano-zinc oxide imparts good antibacterial and UV aging resistance to the roll material. The nanofiber membrane prepared by combining polyurethane and PVDF has excellent waterproof and breathable properties, and the bonding properties of PVDF enable an L-shaped overlap structure, reducing costs while improving the convenience of overlap operations.

Description

Technical Field

[0001] This invention belongs to the field of waterproof membrane technology, specifically relating to a waterproof and breathable membrane that is impermeable. Background Technology

[0002] Waterproof membranes are mainly used in building walls, roofs, tunnels, highways, landfills, etc., to resist external rainwater and groundwater seepage. They are flexible building materials that can be rolled up and serve as a leak-proof connection between the foundation and the building. They are the first line of defense for waterproofing the entire project and play a vital role in the overall project.

[0003] Based on their constituent materials, waterproof membranes commonly used in construction engineering are classified into three types: asphalt waterproof membranes, synthetic polymer waterproof membranes, and modified asphalt waterproof membranes. Synthetic polymer waterproof membranes use rubber and synthetic resins as base materials, with the addition of small amounts of fillers and chemical additives. They are manufactured through multiple processes into sheet-like waterproof materials capable of being rolled up. The membrane has polyester layers on both sides and a polymer layer in the middle. Examples of such membranes include ethylene propylene diene monomer (EPDM) waterproof membranes and neoprene rubber membranes. According to their main components, products can be broadly categorized as: ethylene propylene diene monomer (EPDM) membranes, polyvinyl chloride (PVC) membranes, thermoplastic polyolefin (TPO) waterproof membranes, and polymer self-adhesive pre-laid (MBP) waterproof membranes. Synthetic polymer membranes exhibit high performance indicators, possessing excellent waterproofing, weather resistance, elasticity, and tensile strength.

[0004] Currently, most waterproof membranes on the market are either non-breathable or have very low breathability. When used for roof waterproofing, this hinders ventilation, reducing living comfort. Furthermore, when exposed to sunlight and ultraviolet radiation, these membranes age and develop surface cracks. In the long-term damp environment of roofs and walls, waterproof membranes can breed large amounts of bacteria, which is detrimental to human health. Summary of the Invention

[0005] The purpose of this invention is to provide a waterproof and breathable membrane to improve the breathability and antibacterial properties of waterproof membranes.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] This invention provides a waterproof and breathable roll material, comprising, from top to bottom, a breathable upper layer, a reinforcing fiber layer, a waterproof TPO layer, and a breathable lower layer. The breathable upper layer and the reinforcing fiber layer are bonded together by electrospinning and hot-pressing. Laterally, the breathable upper layer extends the same distance to the left and right as the reinforcing fiber layer, with the rightward extension sealed by hot-melt bonding to the right side of the roll material. The reinforcing fiber layer and the waterproof TPO layer are bonded together by calendering. The waterproof TPO layer and the breathable lower layer are bonded together by electrospinning and hot-pressing. Laterally, the breathable lower layer extends the same distance to the left and right as the waterproof TPO layer, with the leftward extension sealed by hot-melt bonding to the left side of the roll material.

[0008] Both the breathable upper layer and the breathable lower layer are ZnO@PU / PVDF nanofiber membranes;

[0009] Furthermore, the reinforcing fiber layer is a glass fiber base fabric;

[0010] The raw materials of the waterproof TPO layer, by weight, include 20-40 parts of polypropylene resin, 25-35 parts of calcium carbonate powder, 30-40 parts of TPO resin, 15-25 parts of polyethylene resin, 1-5 parts of antioxidant 1010, 1-3 parts of stearic acid, 0.5-2 parts of titanate coupling agent, and 0.5-2 parts of titanium dioxide.

[0011] Adding calcium carbonate powder increases the porosity of the waterproof TPO layer, which can improve the breathability of the roll material.

[0012] Furthermore, the thickness of the impermeable, waterproof, and breathable membrane is 2.0 mm;

[0013] Furthermore, the thickness of the ZnO@PU / PVDF nanofiber membrane is 0.1–0.3 mm;

[0014] Furthermore, the preparation steps of the impermeable, waterproof, and breathable membrane are as follows:

[0015] (1) Mix the raw materials of the waterproof TPO layer in proportion, put them into a twin-screw extruder, heat and melt extrusion, and form a composite material with the glass fiber base cloth through calendering and stretching. The upper layer of the composite material is the reinforcing fiber layer and the lower layer is the waterproof TPO layer.

[0016] (2) Polyurethane particles and PVDF powder were added to a mixed solvent in a mass ratio, and heated and stirred at 80°C to prepare a mixed solution. Nano zinc oxide powder was added to the mixed solution and ultrasonically dispersed to obtain ZnO@PU / PVDF spinning solution.

[0017] (3) Using the composite material as the receiving substrate, ZnO@PU / PVDF spinning solution forms ZnO@PU / PVDF nanofiber membranes on both the upper and lower layers of the composite material through electrospinning. The membrane is then hot-pressed at 170℃ to obtain an impermeable, waterproof and breathable roll material with a breathable upper layer and a breathable lower layer.

[0018] (4) Cut and heat-melt bond the waterproof and breathable membrane.

[0019] Furthermore, the heating temperature of the twin-screw extruder is 230–280°C.

[0020] Furthermore, the mass ratio of polyurethane particles to PVDF powder is 2:8 to 8:2. Polyurethane nanofiber membranes have excellent air permeability but hydrophobic defects, while PVDF has good hydrophobicity and toughness. The blending and modification of the two have a complementary effect.

[0021] Furthermore, the mixed solvent is prepared by mixing a polar solvent and acetone;

[0022] The volume ratio of the polar solvent to acetone is 2:8 to 4:6. The blending of the polar solvent and acetone is beneficial to the dissolution of polyurethane and PVDF.

[0023] The polar solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0024] Furthermore, the total mass percentage of polyurethane particles and PVDF powder in the mixed solution is 10%-15%.

[0025] The nano zinc oxide powder accounts for 1%-5% of the mass of the spinning solution.

[0026] Furthermore, the electrospinning voltage is 25kV, the receiving distance is 10cm, the spinning speed is 1mL / h, and the syringe needle inner diameter is 0.5mm.

[0027] The beneficial effects of this invention are:

[0028] (1) A four-layer waterproof and breathable roll material is formed by combining a breathable upper layer, a reinforcing fiber layer, a waterproof TPO layer and a breathable lower layer. Compared with traditional TPO waterproof roll material, the nanofiber membrane is used as the breathable upper layer and the breathable lower layer. Due to the small pore size and high porosity of the nanofiber membrane structure, the waterproof and breathable properties of the roll material are effectively improved. Moreover, the complex pore structure of the four-layer structure reduces the seepage channels and improves the impermeability.

[0029] (2) Nanofiber membranes are prepared by mixing nano zinc oxide, polyurethane and polyvinylidene fluoride. Nano zinc oxide absorbs, reflects and scatters ultraviolet light to improve the UV resistance of the roll material. Nano zinc oxide has a photocatalytic effect under light irradiation, producing substances such as hydroxide ions, oxygen negative ions and hydrogen peroxide, thereby playing an antibacterial role and giving the roll material antibacterial properties. The chelating effect of polyurethane makes it difficult for nano zinc oxide in the nanofiber membrane to fall off, thus improving the dispersibility.

[0030] (3) Doping with nano zinc oxide can transform polyvinylidene fluoride into a β-phase. The β phase is the secondary phase structure of PVDF, with a lower melting point and higher flexibility, which makes the nanofiber membrane have better adhesion when hot-pressed at a lower temperature and better compatibility with polyurethane.

[0031] (4) By cutting and hot-melting the waterproof and breathable roll material, an L-shaped structure with the extended part of the breathable layer as the overlap is formed. By making reasonable use of the hot-melt bonding performance of ZnO@PU / PVDF nanofiber membrane, the intermediate layer material is saved while making the overlap easy and the sealing performance good. Attached Figure Description

[0032] The invention will now be further described with reference to the accompanying drawings.

[0033] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0034] In the diagram: 1. Breathable upper layer; 2. Reinforcing fiber layer; 3. Waterproof TPO layer; 4. Breathable lower layer. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figure 1This invention provides a waterproof and breathable roll material, comprising a breathable upper layer 1, a reinforcing fiber layer 2, a waterproof TPO layer 3, and a breathable lower layer 4. The breathable upper layer 1 and the reinforcing fiber layer 2 are bonded together by electrospinning and hot-pressing. Laterally, the breathable upper layer 1 extends the same distance to the left and right as the reinforcing fiber layer 2. The rightward extension is sealed by hot-melt bonding to the right side of the roll material. The reinforcing fiber layer 2 and the waterproof TPO layer 3 are bonded together by calendering. The waterproof TPO layer 3 and the breathable lower layer 4 are bonded together by electrospinning and hot-pressing. Laterally, the breathable lower layer 4 extends the same distance to the left and right as the waterproof TPO layer 3. The leftward extension is sealed by hot-melt bonding to the left side of the roll material. When two waterproof and breathable roll materials need to overlap, the leftward extension of the breathable upper layer 1 is hot-melt bonded to the upper surface of the waterproof and breathable roll material, and the rightward extension of the breathable lower layer 4 is hot-melt bonded to the lower surface of the waterproof and breathable roll material, achieving an L-shaped overlap structure.

[0037] Example 1

[0038] Weigh the raw materials according to the following weight proportions: 30 parts polypropylene resin, 30 parts calcium carbonate powder, 35 parts TPO resin, 20 parts polyethylene resin, 3 parts antioxidant 1010, 2 parts stearic acid, 1 part titanate coupling agent, and 1 part titanium dioxide. Mix the raw materials and feed them into a twin-screw extruder at a temperature of 250℃ for melt extrusion. Introduce the glass fiber base fabric as a reinforcing fiber layer into the drawing rolls. Extrude and draw the composite reinforcing fiber layer and the waterproof TPO layer through the upper and lower rolls to form a composite material. The upper layer of the composite material is the reinforcing fiber layer, and the lower layer is the waterproof TPO layer.

[0039] A mixed solvent with a DMF / acetone volume ratio of 3:7 was prepared. Polyurethane (PU) particles and PVDF powder were added to the mixed solvent at a mass ratio of 5:5. The mixture was heated and stirred at 80°C to prepare a mixed solution. The total mass percentage of PU and PVDF in the mixed solution was 12%. Then, nano zinc oxide powder was added to the mixed solution, with a mass percentage of 3%. The mixture was ultrasonically dispersed for 1 hour to obtain a spinning solution, which was then cooled to room temperature.

[0040] The electrospinning voltage was set to 25kV, the receiving distance to 10cm, the spinning speed to 1mL / h, and the syringe needle inner diameter to 0.5mm. The composite material was used as the receiving substrate, and the spinning solution was sprayed through the syringe to form a ZnO@PU / PVDF nanofiber membrane with a thickness of 0.2mm on both sides of the composite material. Further hot-pressing treatment at 170℃ was performed to bond the ZnO@PU / PVDF nanofiber membrane to the composite material as a breathable upper and lower layer, resulting in a waterproof and breathable roll material with a thickness of 2.0mm.

[0041] The obtained waterproof and breathable membrane is further cut and hot-melt bonded to obtain a membrane with... Figure 1The shown is a waterproof and breathable roll material with an overlapping edge structure.

[0042] Example 2

[0043] The difference from Example 1 is that the mass ratio of polyurethane (PU) particles to PVDF powder is 2:8, while the other steps are the same as in Example 1.

[0044] Example 3

[0045] The difference from Example 1 is that the mass ratio of polyurethane (PU) particles to PVDF powder is 8:2, while the other steps are the same as in Example 1.

[0046] Example 4

[0047] The difference from Example 1 is that the nano zinc oxide powder accounts for 1% of the total mass, while the other steps are the same as in Example 1.

[0048] Example 5

[0049] The difference from Example 1 is that the nano zinc oxide powder accounts for 5% of the total mass, while the other steps are the same as in Example 1.

[0050] Example 6

[0051] The difference from Example 1 is that the thickness of the ZnO@PU / PVDF nanofiber membrane is 0.1 mm, while the other steps are the same as in Example 1.

[0052] Example 7

[0053] The difference from Example 1 is that the thickness of the ZnO@PU / PVDF nanofiber membrane is 0.3 mm, while the other steps are the same as in Example 1.

[0054] Example 8

[0055] Weigh the raw materials according to the following weight proportions: 20 parts polypropylene resin, 25 parts calcium carbonate powder, 30 parts TPO resin, 15 parts polyethylene resin, 1 part antioxidant 10101, 1 part stearic acid, 0.5 parts titanate coupling agent, and 0.5 parts titanium dioxide. Mix the raw materials and feed them into a twin-screw extruder at a temperature of 230℃ for melt extrusion. Introduce the glass fiber base fabric as a reinforcing fiber layer into the drawing rolls. Extrude and draw the composite reinforcing fiber layer and the waterproof TPO layer through the upper and lower rolls to form a composite material. The upper layer of the composite material is the reinforcing fiber layer, and the lower layer is the waterproof TPO layer.

[0056] A mixed solvent with a DMAC / acetone volume ratio of 2:8 was prepared. Polyurethane (PU) particles and PVDF powder were added to the mixed solvent at a mass ratio of 5:5. The mixture was heated and stirred at 80°C to prepare a mixed solution. The total mass percentage of PU and PVDF in the mixed solution was 10%. Then, nano zinc oxide powder was added to the mixed solution, with a mass percentage of 3%. The mixture was ultrasonically dispersed for 1 hour to obtain a spinning solution, which was then cooled to room temperature.

[0057] The electrospinning voltage was set to 25kV, the receiving distance to 10cm, the spinning speed to 1mL / h, and the syringe needle inner diameter to 0.5mm. The composite material was used as the receiving substrate, and the spinning solution was sprayed through the syringe to form a ZnO@PU / PVDF nanofiber membrane with a thickness of 0.2mm on both sides of the composite material. Further hot-pressing treatment at 170℃ was performed to bond the ZnO@PU / PVDF nanofiber membrane to the composite material as a breathable upper and lower layer, resulting in a waterproof and breathable roll material with a thickness of 2.0mm.

[0058] The obtained waterproof and breathable membrane is further cut and hot-melt bonded to obtain a membrane with... Figure 1 The shown is a waterproof and breathable roll material with an overlapping edge structure.

[0059] Example 9

[0060] The raw materials are weighed according to the following weight proportions: 40 parts polypropylene resin, 35 parts calcium carbonate powder, 40 parts TPO resin, 25 parts polyethylene resin, 10105 parts antioxidant, 3 parts stearic acid, 2 parts titanate coupling agent, and 2 parts titanium dioxide. The raw materials are stirred and mixed and then fed into a twin-screw extruder at a temperature of 280℃ for melt extrusion. The glass fiber base cloth is introduced into the drawing roll as a reinforcing fiber layer. The reinforcing fiber layer and the waterproof TPO layer are extruded and drawn together by the upper and lower rolls to form a composite material. The upper layer of the composite material is the reinforcing fiber layer, and the lower layer is the waterproof TPO layer.

[0061] A mixed solvent with a DMAC / acetone volume ratio of 2:8 was prepared. Polyurethane (PU) particles and PVDF powder were added to the mixed solvent at a mass ratio of 5:5. The mixture was heated and stirred at 80°C to prepare a mixed solution. The total mass percentage of PU and PVDF in the mixed solution was 15%. Then, nano zinc oxide powder was added to the mixed solution, with a mass percentage of 3%. The mixture was ultrasonically dispersed for 1 hour to obtain a spinning solution, which was then cooled to room temperature.

[0062] The electrospinning voltage was set to 25kV, the receiving distance to 10cm, the spinning speed to 1mL / h, and the syringe needle inner diameter to 0.5mm. The composite material was used as the receiving substrate, and the spinning solution was sprayed through the syringe to form a ZnO@PU / PVDF nanofiber membrane with a thickness of 0.2mm on both sides of the composite material. Further hot-pressing treatment at 170℃ was performed to bond the ZnO@PU / PVDF nanofiber membrane to the composite material as a breathable upper and lower layer, resulting in a waterproof and breathable roll material with a thickness of 2.0mm.

[0063] The obtained waterproof and breathable membrane is further cut and hot-melt bonded to obtain a membrane with... Figure 1 The shown is a waterproof and breathable roll material with an overlapping edge structure.

[0064] Comparative Example 1

[0065] Compared to Example 1, nano titanium dioxide powder was used instead of nano zinc oxide powder, while the other steps were the same as in Example 1.

[0066] Comparative Example 2

[0067] Compared to Example 1, polyurethane (PU) and nano zinc oxide powder were used to prepare the spinning solution, and PVDF powder was removed. Other steps were the same as in Example 1.

[0068] Comparative Example 3

[0069] Compared to Example 1, PVDF powder and nano zinc oxide powder were used to prepare the spinning solution to remove polyurethane (PU), while other steps were the same as in Example 1.

[0070] Comparative Example 4

[0071] Compared to Example 1, polyurethane (PU) and PVDF powder were used to prepare the spinning solution, and nano zinc oxide powder was removed. Other steps were the same as in Example 1.

[0072] Comparative Example 5

[0073] Compared to Example 1, the waterproof and breathable roll material does not have a breathable upper layer and a breathable lower layer. Instead, it uses fiberglass base fabric as the middle reinforcing fiber layer and two layers of calendered composite waterproof TPO layers.

[0074] Weigh the raw materials according to the following proportions: 30 parts polypropylene resin, 30 parts calcium carbonate powder, 35 parts TPO resin, 20 parts polyethylene resin, 3 parts antioxidant 1010, 2 parts stearic acid, 1 part titanate coupling agent, and 1 part titanium dioxide. Mix the raw materials thoroughly and feed them in equal amounts into two twin-screw extruders at 250℃ for melt extrusion. Introduce the fiberglass base fabric as the intermediate reinforcing fiber layer into the drawing rolls. Extrude the composite waterproof TPO upper layer, reinforcing fiber layer, and waterproof TPO lower layer through a three-roll extrusion process to form a roll material. The roll material is shown below. Figure 1The layers are overlapped as shown, with the upper waterproof TPO layer similar to the breathable upper layer of the embodiment, and the lower waterproof TPO layer similar to the breathable lower layer of the embodiment.

[0075] Performance tests were conducted on Examples 1-9 and Comparative Examples 1-5, and the results are shown in Table 1.

[0076] Mechanical properties and water permeability / absorption properties were tested in accordance with GB 27789-2011 "Thermoplastic Polyolefin (TPO) Waterproof Membrane";

[0077] Gas permeability was tested in accordance with GB / T 1038.1-2022 "Test methods for gas permeability of plastic films and sheets - Part 1: Differential pressure method";

[0078] The antibacterial performance was tested in accordance with GB / T 30706-2014 "Test Method and Evaluation of Antibacterial Performance of Photocatalytic Antibacterial Materials and Products under Visible Light Irradiation".

[0079] Table 1

[0080]

[0081]

[0082] As shown in Table 1, in Examples 1-3, adjusting the mass ratio of urethane (PU) particles to PVDF powder in the ZnO@PU / PVDF nanofiber membrane resulted in an increased PU content. This led to an initial increase followed by a decrease in the elongation at break of the roll material, an increase in water absorption, an increase in air permeability, and a slight decrease in water permeability. Excessive PU was detrimental to waterproofing performance, while a suitable proportion was beneficial for improving elongation at break. Compared to Example 1, Examples 4 and 5 showed different proportions of nano-zinc oxide. Increased nano-zinc oxide content significantly improved antibacterial and anti-aging properties. In Examples 6 and 7, the thickness of the ZnO@PU / PVDF nanofiber membrane differed from that in Example 1. Increased thickness enhanced mechanical and impermeability properties, but excessive thickness significantly reduced air permeability. The roll materials in Examples 8 and 9 exhibited similar performance to those in Example 1, with good overall performance. In Comparative Example 1, nano-titanium dioxide replaced nano-zinc oxide, but nano-zinc oxide showed superior antibacterial and UV-resistant properties compared to nano-titanium dioxide. In Comparative Example 2, the water absorption rate of the roll material without PVDF increased, its waterproof performance decreased, and the seam peel strength was significantly reduced. In Comparative Example 3, the air permeability of the roll material without polyurethane was poor, and its antibacterial and UV resistance were slightly reduced, mainly due to the obvious agglomeration of nano-zinc oxide. In Comparative Example 4, without the addition of nano-zinc oxide, the antibacterial and anti-aging properties of the roll material decreased significantly. Comparative Example 5 used a TPO waterproof roll material prepared by a traditional process. TPO material has poor adhesion compared to PVDF material, resulting in poor seam peel strength at overlaps and very low gas permeability, leading to significantly weaker antibacterial and anti-aging properties.

[0083] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0084] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waterproof and breathable roll material, characterized in that, From top to bottom, it includes a breathable upper layer (1), a reinforcing fiber layer (2), a waterproof TPO layer (3), and a breathable lower layer (4). The breathable upper layer (1) and the reinforcing fiber layer (2) are bonded by electrospinning and hot pressing. The breathable upper layer (1) extends to the left and right by the same distance as the reinforcing fiber layer (2) in the horizontal direction. The rightward extension is bonded and sealed by hot melting and the right side of the roll material. The reinforcing fiber layer (2) and the waterproof TPO layer (3) are bonded by calendering. The waterproof TPO layer (3) and the breathable lower layer (4) are bonded by electrospinning and hot pressing. The breathable lower layer (4) extends to the left and right by the same distance as the waterproof TPO layer (3) in the horizontal direction. The leftward extension is bonded and sealed by hot melting and the left side of the roll material. Both the breathable upper layer (1) and the breathable lower layer (4) are ZnO@PU / PVDF nanofiber membranes, and the thickness of the ZnO@PU / PVDF nanofiber membrane is 0.1~0.3mm. The reinforcing fiber layer (2) is a glass fiber base fabric; The raw materials of the waterproof TPO layer (3) by weight include 20-40 parts of polypropylene resin, 25-35 parts of calcium carbonate powder, 30-40 parts of TPO resin, 15-25 parts of polyethylene resin, 1-5 parts of antioxidant 1010, 1-3 parts of stearic acid, 0.5-2 parts of titanate coupling agent and 0.5-2 parts of titanium dioxide; Waterproof and breathable membrane is prepared through the following steps: S1. Mix the raw materials of waterproof TPO layer (3) thoroughly according to the proportion, put them into a twin-screw extruder, heat and melt extrusion, and form a composite material with glass fiber base cloth through calendering and stretching. The upper layer of the composite material is the reinforcing fiber layer (2), and the lower layer is the waterproof TPO layer (3). S2. Polyurethane particles and PVDF powder are added to a mixed solvent in a certain mass ratio, and the mixture is heated and stirred at 80°C to prepare a mixed solution. Nano zinc oxide powder is added to the mixed solution and ultrasonically dispersed for 1 hour to obtain ZnO@PU / PVDF spinning solution. The mass ratio of polyurethane particles to PVDF powder is 2:8~8:

2. The mass percentage of nano zinc oxide powder in the spinning solution is 1%-5%. S3. Using the composite material as the receiving substrate, ZnO@PU / PVDF spinning solution is electrospun to form ZnO@PU / PVDF nanofiber membranes on both the upper and lower layers of the composite material. The membrane is then hot-pressed at 170℃ to obtain a waterproof and breathable roll material with the upper layer being a breathable upper layer (1) and the lower layer being a breathable lower layer (4). S4. Cut and hot-melt bond the waterproof and breathable membrane to form an L-shaped overlap structure.

2. The waterproof and breathable membrane according to claim 1, characterized in that, The thickness of the waterproof and breathable membrane is 2.0 mm.

3. The waterproof and breathable membrane according to claim 1, characterized in that, The heating temperature of the twin-screw extruder is 230~280℃.

4. The waterproof and breathable membrane according to claim 1, characterized in that, The mixed solvent is prepared by mixing a polar solvent and acetone; The volume ratio of the polar solvent to acetone is 2:8 to 4:6; The polar solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

5. The waterproof and breathable membrane according to claim 1, characterized in that, The combined mass percentage of polyurethane particles and PVDF powder in the mixed solution is 10%-15%.

6. The waterproof and breathable membrane according to claim 1, characterized in that, The electrospinning voltage is 25kV, the receiving distance is 10cm, the spinning speed is 1mL / h, and the syringe needle inner diameter is 0.5mm.

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