A waterproof vapor permeable membrane

Abstract

The application provides a waterproof vapor-permeable membrane. The waterproof vapor-permeable membrane comprises a first surface layer, a second surface layer and an intermediate layer arranged between the first surface layer and the second surface layer; the first surface layer and the second surface layer comprise a first polymer, and the intermediate layer comprises a second polymer; the first polymer comprises one or more functional groups selected from carboxyl, ester, anhydride and amino; and the second polymer is a hydrophilic thermoplastic polymer. The waterproof vapor-permeable membrane has good waterproof and vapor-permeable functions, and can be bonded to inorganic cementitious materials such as finishing mortar and putty without adhesive coating, so that continuous construction can be carried out and process time is saved.

Description

Technical Field

[0001] This invention belongs to the field of waterproofing and relates to a waterproof and breathable membrane. Background Technology

[0002] With the widespread application of exterior wall waterproofing, actively promoting building energy conservation and ensuring proper waterproofing of building walls are of great significance in practical development. Waterproof and breathable membranes are functional materials whose main function is to block the penetration of liquid water while allowing water vapor to pass through. They possess windproof, waterproof, and breathable properties, effectively blocking rainwater intrusion, reducing air convection heat loss, and simultaneously allowing water vapor inside the structure to diffuse and escape, preventing condensation and mold growth. They also offer moisture-proof and healthy living conditions.

[0003] There are many reports on waterproof and breathable membranes. For example, CN214688362U discloses a waterproof membrane for buildings, which includes a non-woven fabric layer, a PE film layer disposed on one side of the non-woven fabric layer, and a core layer disposed between the non-woven fabric layer and the PE film. The core layer is a three-dimensional structure layer formed by the aggregation of polyolefin fibers, and there are multiple interconnected channels in the core layer and / or between the core layer and the non-woven fabric and / or between the core layer and the PE film layer that can communicate with the outside world to achieve good breathability. CN202805837U discloses a composite waterproof and breathable membrane, in which the middle layer substrate is made of thermoplastic polyurethane elastomer, and the membranes on both sides of the substrate are polypropylene film or polyester non-woven fabric. The thermoplastic polyurethane elastomer and the membranes on both sides are bonded together by hot melt adhesive or hot pressing, which is used for breathable waterproofing of building exterior walls and roofs. However, none of the waterproof and breathable membranes reported above can be directly bonded to plastering mortar and putty. They generally require styrene or butyl hot-melt pressure-sensitive adhesive as a self-adhesive layer. After applying the adhesive, the membrane's breathability rapidly decreases to 10 g / m³. 2 • Below 24 hours, it severely affects vapor permeability.

[0004] To improve vapor permeability, the coating area is typically reduced, using methods such as spot coating or mesh coating to enhance permeability. For example, patent CN205314378U reports a self-adhesive waterproof and breathable membrane with a waterproof and breathable membrane on top and a release liner on the bottom. The release liner and the waterproof and breathable membrane are connected by a hot-melt pressure-sensitive adhesive layer. The hot-melt pressure-sensitive adhesive layer uses a permeable micropore, with the micropore diameter limited to 50-300 μm. The micropore area occupies 70-85% of the hot-melt pressure-sensitive adhesive layer area to improve vapor permeability. However, this technology inevitably leads to complex manufacturing processes, inconsistent vapor permeability over time, and incomplete adhesion to adjacent structural layers of external wall insulation materials.

[0005] In summary, how to make waterproof and breathable membranes possess both good waterproof and breathable properties and good adhesive properties remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This invention provides a waterproof and breathable membrane. Through special design of its composition and structure, it not only possesses excellent waterproof and breathable functions but also achieves a strong bond with insulation system materials such as plastering mortar and putty without the need for adhesives. When applied to the exterior wall insulation layer, it can be directly laid on the mortar surface using a wet-laying process, followed by applying putty directly to the waterproof and breathable membrane surface. This allows for continuous construction, saving time and effort.

[0007] This invention provides a waterproof and breathable membrane, which includes a first surface layer, a second surface layer, and an intermediate layer disposed between the first surface layer and the second surface layer;

[0008] The first and second surface layers comprise a first polymer, and the intermediate layer comprises a second polymer;

[0009] The first polymer contains one or more functional groups selected from carboxyl, ester, acid anhydride, or amino groups;

[0010] The second polymer is a hydrophilic thermoplastic polymer.

[0011] The waterproof and breathable membrane as described above, wherein the first polymer comprises one or more of polyvinyl acetate, polyethylene methyl acrylate, ethylene ethyl acrylate, ethylene butyl acrylate, polyacrylate, thermoplastic polyurethane, and maleic anhydride-grafted polyolefin.

[0012] The waterproof and breathable membrane as described above, wherein the second polymer comprises one or more of polyether segments, polyacrylic acid segments, polyurethane segments, polyvinyl alcohol segments, polyamide segments, and polyester segments;

[0013] Preferably, the second polymer comprises one or more of polyvinyl alcohol, polycaprolactam, polyvinyl acetate, polyurethane, polybutylene terephthalate, and polylactic acid.

[0014] In the waterproof and breathable membrane described above, the mass content of the first polymer in the first surface layer and the second surface layer is 40% to 80%.

[0015] And / or, in the intermediate layer, the mass content of the second polymer is 50% to 90%.

[0016] The waterproof and breathable membrane described above, wherein the first surface layer and the second surface layer further include a first inorganic filler;

[0017] Preferably, the first inorganic filler includes one or more of calcium carbonate, silicon dioxide, wollastonite, aluminum hydroxide, silicate cement, and diatomaceous earth.

[0018] In the waterproof and breathable membrane described above, the mass content of the first inorganic filler in the first surface layer and the second surface layer is 20% to 60%.

[0019] The waterproof and breathable membrane described above, wherein the intermediate layer further includes a second inorganic filler;

[0020] Preferably, the second inorganic filler includes one or more of silica, wollastonite, sepiolite, montmorillonite, and calcium carbonate.

[0021] In the waterproof and breathable membrane described above, the mass content of the second inorganic filler in the intermediate layer is not higher than 40%.

[0022] The waterproof and breathable membrane described above, wherein the first surface layer and the second surface layer have a porous structure.

[0023] The waterproof and breathable membrane as described above, wherein the intermediate layer further includes a mesh fabric, and the second polymer is loaded on the surface of the mesh fabric;

[0024] Preferably, the mesh size of the mesh fabric is no greater than 8mm × 8mm.

[0025] The waterproof and breathable membrane described above, wherein the thickness of the first surface layer and the second surface layer is 100~400μm;

[0026] And / or, the thickness of the intermediate layer is 150μm~500μm.

[0027] The waterproof and breathable membrane described above, wherein the water vapor permeation rate of the waterproof and breathable membrane is ≥100 g / m² per 24 hours. 2 ;

[0028] The bonding strength between the waterproof and breathable membrane and the plastering mortar or putty is ≥0.4MPa.

[0029] The implementation of this invention has at least the following beneficial effects:

[0030] 1) This invention provides a waterproof and breathable membrane having a composite structure consisting of a first outer layer, an intermediate layer, and a second outer layer sequentially laminated together. The first outer layer contains a polymer with functional groups such as carboxyl groups, ester groups, acid anhydrides, and amino groups. These groups enable the two outer outer layers of the waterproof and breathable membrane to form good adhesion with conventionally used inorganic hydration cementitious materials such as mortar and putty, eliminating the need for further adhesive coating and allowing for continuous construction, thus saving time and labor. The intermediate layer comprises a hydrophilic thermoplastic polymer that can absorb water vapor molecules and transfer them to the outside through a diffusion mechanism, while preventing liquid water molecules from passing through, thus providing good waterproof and breathable functionality.

[0031] 2) This invention, through the design of the composition and structure of the waterproof and breathable membrane, enables it to achieve a strong bond with insulation system materials such as plastering mortar and putty without the need for adhesives, while also providing excellent waterproof and breathable functionality. When applied to the exterior wall insulation layer, it can be directly laid on the mortar surface using a wet-laying process, followed by applying putty directly to the waterproof and breathable membrane surface, allowing for continuous construction and saving time and effort. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a waterproof and breathable membrane according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of a waterproof and breathable membrane according to another embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 11: First surface layer;

[0036] 12: Intermediate layer;

[0037] 12A: Second polymer film layer;

[0038] 12B: Mesh fabric;

[0039] 13: Second surface layer. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] The first aspect of this invention provides a waterproof and breathable membrane. Figure 1 This is a schematic diagram of the structure of a waterproof and breathable membrane according to an embodiment of the present invention, as shown below. Figure 1 As shown, the waterproof and breathable membrane includes a first surface layer 11, a second surface layer 13, and an intermediate layer 12 disposed between the first surface layer and the second surface layer;

[0042] The first surface layer 11 and the second surface layer 13 comprise a first polymer, and the intermediate layer 12 comprises a second polymer;

[0043] The first polymer contains one or more functional groups selected from carboxyl, ester, acid anhydride, and amino groups;

[0044] The second polymer is a hydrophilic thermoplastic polymer.

[0045] The waterproof and breathable membrane of the present invention comprises a polymer having one or more functional groups selected from carboxyl, ester, acid anhydride and amino groups in its surface layer. These functional groups enable the polymer to have strong polarity, forming good adhesion with inorganic hydration cementitious materials such as mortar and putty. It can be directly applied to the mortar surface and then putty can be applied without the need for adhesive, thus forming good adhesion. It also maintains high storage stability before construction. Its middle layer comprises a hydrophilic thermoplastic polymer. The hydrophilic groups can absorb water vapor molecules and transfer them to the other side through a diffusion mechanism, thereby providing good breathability.

[0046] In summary, this invention features a special structural and compositional design for the waterproof and breathable membrane, enabling it to achieve excellent waterproof and breathable properties while forming a strong bond with external wall insulation materials without the need for adhesive coating. This allows for continuous construction and saves time and effort.

[0047] In one specific embodiment, the first polymer includes one or more of polyvinyl acetate, polyethylene methyl acrylate, ethylene ethyl acrylate, ethylene butyl acrylate, polyacrylate, thermoplastic polyurethane, and maleic anhydride-grafted polyolefin. These polymers, possessing polar groups such as ester groups and acid anhydrides, can provide good adhesion between the first and second surface layers.

[0048] In one specific embodiment, the second polymer comprises one or more of polyether segments, polyacrylic acid segments, polyamide segments, and polyester segments. All of these segments possess strong hydrophilic properties, which is beneficial for achieving excellent vapor permeability in the waterproof and breathable membrane.

[0049] Polymers having the above-mentioned hydrophilic segments include, but are not limited to, one or more of polyvinyl alcohol, polycaprolactam, polyvinyl acetate, polyurethane, polybutylene terephthalate (PBT), and polylactic acid (PLA).

[0050] It should be noted that, in addition to the first polymer, the first and second surface layers may also include one or more of polyethylene, ethylene-α-olefin copolymer, polyvinyl chloride, polymethyl methacrylate, and polypropylene. To ensure good adhesion between the first and second surface layers, the mass content of the first polymer in the first and second surface layers is controlled to be no less than 35%, preferably 40% to 80%. In addition to the hydrophilic second polymer, the intermediate layer may also include a non-hydrophilic thermoplastic polymer to enhance the mechanical strength of the intermediate layer, as long as the intermediate layer as a whole has hydrophilic properties. To ensure good vapor permeability of the intermediate layer, the mass content of the second polymer in the intermediate layer is controlled to be no less than 50%, preferably 50% to 90%.

[0051] For example, the content of the first polymer in the first and second surface layers can be any combination of 40 wt%, 45 wt%, 50 wt%, 55 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, or more; the content of the second polymer in the intermediate layer can be any combination of 50 wt%, 55 wt%, 60 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or more.

[0052] In one specific embodiment, the first and second surface layers further include a first inorganic filler. Adding the inorganic filler can improve the mechanical strength of the waterproof and breathable membrane. Furthermore, the inorganic filler with a certain particle size can form a microporous structure in the polymer membrane of the surface layer, allowing water vapor to pass through while preventing liquid water permeation, thus giving both the first and second surface layers good breathability, thereby improving the overall breathability of the waterproof and breathable membrane.

[0053] In one preferred embodiment, the first inorganic filler includes one or more of calcium carbonate, silica, wollastonite, aluminum hydroxide, silicate cement, and diatomaceous earth. These inorganic fillers are all conventionally used and each has its own characteristics, allowing for selection based on specific application requirements. For example, calcium carbonate is an inexpensive filler that can significantly reduce material costs; silica has excellent heat resistance and good adsorption capacity; wollastonite can significantly improve the strength and toughness of plastics and rubber; aluminum hydroxide can decompose and release water vapor at high temperatures, exhibiting good flame retardant effects and chemical stability; silicate cement can be mixed with various aggregates and additives, possessing good chemical resistance to meet different construction needs; and diatomaceous earth has the advantage of low density, enabling the waterproof and breathable membrane to be lighter.

[0054] Adding a certain amount of inorganic filler can improve the mechanical and vapor permeability of waterproof and breathable membranes, but excessive filler may cause the material to become brittle, thus affecting its waterproof performance. In a preferred embodiment, the mass content of the first inorganic filler in the first and second surface layers is 20% to 60%. Within this range, the waterproof and breathable membrane can exhibit superior overall performance.

[0055] For example, the content of the first inorganic filler in the first and second surface layers can be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, or any combination of the above.

[0056] In one specific embodiment, the intermediate layer further includes a second inorganic filler. Similarly, the addition of the second inorganic filler helps to improve the mechanical properties and vapor permeability of the intermediate layer, thereby improving the overall performance of the waterproof and breathable membrane.

[0057] In a preferred embodiment, the second inorganic filler includes one or more of silica, wollastonite, sepiolite, montmorillonite, and calcium carbonate. When mixed with a hydrophilic polymer, the above-mentioned second inorganic filler can absorb and permeate water, giving the intermediate layer excellent mechanical properties and vapor permeability.

[0058] The intermediate layer is the main structure that provides the waterproof function of the waterproof and breathable membrane, and a higher polymer content is beneficial for forming a denser waterproof layer, thus providing superior waterproof performance. Based on this, the mass content of the second inorganic filler in the intermediate layer is controlled to not exceed 40%. Within this content range, it not only helps maintain the good waterproof performance of the waterproof and breathable membrane, but also gives it good tensile strength, toughness, and weather resistance, resulting in a longer service life. For example, the content of the second inorganic filler in the intermediate layer can be 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, or any combination thereof.

[0059] In a preferred embodiment, the first and second surface layers have a porous structure. This porous structure facilitates the timely diffusion of water vapor permeating from the intermediate layer out of the waterproof and breathable membrane, forming multiple channels that connect water vapor to the outside environment, thereby further improving the breathability of the waterproof and breathable membrane.

[0060] This invention does not specifically limit the realization of porous structures; the corresponding method can be selected according to the desired pore size, shape, and distribution. For example, a porous structure can be generated by using phase separation, template method, foaming method, stretching method, etching method, electrospinning, etc., to form a polymer film with a first and a second surface layer.

[0061] Figure 2 This is a schematic diagram of the structure of a waterproof and breathable membrane according to another embodiment of the present invention, as shown below. Figure 2 As shown, the intermediate layer 12 also includes a mesh fabric 12B, with a second polymer loaded on the surface of the mesh fabric 12B. The second polymer may be loaded on only one side of the mesh fabric 12B, or it may be loaded on both sides. Figure 2 In the embodiment shown, the second polymer is loaded on both sides of the mesh fabric as a second polymer film layer 12A.

[0062] Mesh fabric is a type of fabric with a mesh structure that allows water vapor to pass through, thus maintaining good breathability in the intermediate layer. In addition, mesh fabric typically has high tensile strength and chemical resistance, providing beneficial reinforcement and strengthening effects, and improving the structural strength of the waterproof and breathable membrane.

[0063] This invention does not impose any special limitations on the material of the mesh fabric; it can be any mesh fabric widely used in the construction industry, including but not limited to fiberglass mesh fabric, polyester fiber mesh fabric, polypropylene fiber mesh fabric, nylon mesh fabric, carbon fiber mesh fabric, etc. Mesh fabrics made of the above materials can retain more than 90% of their mechanical strength after immersion in water.

[0064] The mesh size of the mesh fabric also affects its strength and breathability. Smaller mesh sizes mean more fiber interweaving, which is beneficial for improving the strength and stability of the mesh fabric, but detrimental to breathability. Larger mesh sizes, while more beneficial for breathability, are less desirable for the strength of the mesh fabric. Therefore, the mesh size of the mesh fabric should be controlled to be no larger than 8mm × 8mm to ensure that the mesh fabric has both high strength and good breathability.

[0065] Understandably, the thickness of the waterproof and breathable membrane also affects its waterproofness, breathability, and mechanical strength. Specifically, a thicker first and second surface layer is more conducive to achieving greater adhesive strength, but a thicker layer is less conducive to the breathability of the surface layer. Similarly, a thicker intermediate layer is more conducive to achieving excellent waterproof performance and high mechanical strength, but excessive thickness will also lead to increased costs. Based on the above considerations, the thickness of the first and second surface layers is controlled at 100~400μm, and the thickness of the intermediate layer is controlled at 150μm~500μm, so that the waterproof and breathable membrane has excellent waterproofness, breathability, and mechanical strength. For example, the thickness of the first and second surface layers can be any combination of 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm or more; the thickness of the intermediate layer can be any combination of 150μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm or more.

[0066] This invention, through the control of the composition and structure of the waterproof and breathable membrane, enables the membrane to possess both excellent breathability and adhesive strength, achieving a water vapor permeability of ≥100 g / m³. 2 • After 24 hours, the bonding strength with the plastering mortar and putty is ≥0.4MPa.

[0067] In one specific embodiment, the waterproof and breathable membrane of the present invention can be prepared by the following method:

[0068] After granulating the raw materials that make up the first surface layer, the second surface layer and the intermediate layer, the granules are extruded to form the first surface layer membrane, the second surface layer membrane and the intermediate layer membrane respectively. Finally, the first surface layer membrane, the intermediate layer membrane and the second surface layer membrane are co-extruded and compounded to form a waterproof and breathable membrane.

[0069] Granulation of raw materials allows for more thorough and uniform mixing. When the raw materials for the first, second, and intermediate layers are unfilled, granulation can be eliminated, and the raw materials can be directly extruded to form the first, second, and intermediate layer films, respectively.

[0070] The waterproof and breathable membrane provided by the present invention will be described in detail below with reference to specific embodiments.

[0071] In the following embodiments, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods. Experimental methods without specific conditions shall be performed in accordance with conventional methods and conditions in the art, or according to the product instructions.

[0072] Example 1

[0073] This embodiment provides a waterproof and breathable membrane, the preparation method of which includes the following steps:

[0074] 1. Preparation of the interlayer membrane: PBT (Ultradur® B 4300 G2BK5110, BASF), EVA (28005, LG Chem), EVA (40W, Mitsui Chemicals), and calcium carbonate (CARB-5JI, Omia) were mixed and extruded into granules according to a mass ratio of 50:20:10:20. After granulation, the mixture was fed into the first extruder to obtain an interlayer membrane with a thickness of 200 μm.

[0075] 2. Preparation of the first and second surface films: EVA (28005, LG Chem), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), ordinary silicate cement (AALBORG 42.5), and calcium carbonate (CARB-5JI, Omia) were mixed and extruded into granules according to a mass ratio of 20:40:15:25. After granulation, the mixture was fed into a second extruder to obtain the first and second surface films with thicknesses of 200 μm, respectively.

[0076] 3. After placing the first surface layer membrane, the intermediate layer membrane, and the second surface layer membrane in sequence, they are co-extruded at 170℃-180℃ to obtain a waterproof and breathable membrane.

[0077] Example 2

[0078] This embodiment provides a waterproof and breathable membrane, the preparation method and composition of which are basically the same as those in Example 1. The difference is that the intermediate layer raw materials include PLA (REVODE721, Haizheng Biotechnology), EVA (28005, LG Chem), EVA (40W, Mitsui Chemicals), and montmorillonite (WSG-PN06, Shanghai Wanzhao) in a mass ratio of 50:20:10:20.

[0079] Example 3

[0080] This embodiment provides a waterproof and breathable membrane, the preparation method of which includes the following steps:

[0081] 1. Preparation of the interlayer membrane: EVA (28005, LG Chem), polylactic acid (REVODE101, Zhejiang Hisun), calcium carbonate (CARB-5JI, Omia), and montmorillonite (WSG-PN06, Shanghai Wanzhao) were mixed and extruded into granules according to a mass ratio of 20:50:20:10. After granulation, the interlayer membrane with a thickness of 150 μm was obtained by extrusion through the first extruder.

[0082] 2. Preparation of the first and second surface films: Ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), acrylate copolymer (LK2140, KURARAY CO.,LTD), silica (AEROSIL® 200, Degussa), and calcium carbonate (CARB-5JI, Omia) were mixed and extruded into granules according to a mass ratio of 20:40:10:20:10. After granulation, two films with a thickness of 250 μm were obtained by extrusion through a second extruder, which are the first surface film and the second surface film, respectively.

[0083] 3. After placing the first surface layer membrane, the intermediate layer membrane, and the second surface layer membrane in sequence, they are co-extruded at 170℃-180℃ to obtain a waterproof and breathable membrane.

[0084] Example 4

[0085] This embodiment provides a waterproof and breathable membrane, the preparation method of which includes the following steps:

[0086] 1. Preparation of the intermediate layer

[0087] The intermediate layer of this embodiment includes a three-layer structure consisting of a first non-porous and moisture-permeable membrane layer, a mesh fabric layer, and a second non-porous and moisture-permeable membrane layer arranged sequentially.

[0088] The mesh fabric layer has a mesh size of 3mm × 3mm and a weight of 110g / m². 2 Composed of a mesh fabric;

[0089] The preparation process of the first and second non-porous permeable membrane layers is as follows: EVA (28005, LG Chem), polylactic acid (REVODE101, Zhejiang Hisun), calcium carbonate (CARB-5JI, Omia), and montmorillonite (WSG-PN06, Shanghai Wanzhao) are extruded and granulated according to a mass ratio of 20:50:20:10, and then extruded through the first extruder to obtain two membranes with a thickness of 150μm, which are the first and second non-porous permeable membrane layers, respectively.

[0090] 2. Preparation of the first and second surface layers: Ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), acrylate copolymer (LK2140, KURARAY CO.,LTD), silica (AEROSIL® 200, Degussa), and calcium carbonate (CARB-5JI, Omia) were mixed and extruded into granules according to a mass ratio of 20:40:10:20:10. After granulation, the mixture was fed into a second extruder to obtain two films with a thickness of 200 μm, which are the first and second surface layers, respectively.

[0091] 3. The first surface membrane, the first non-porous breathable membrane, the mesh fabric, the second non-porous breathable membrane, and the second surface membrane are placed in sequence and then co-extruded at 170℃-180℃ to obtain a waterproof and breathable membrane.

[0092] Example 5

[0093] This embodiment provides a waterproof and breathable membrane, the preparation method of which is basically the same as that in Example 4, except that:

[0094] The intermediate layer materials were replaced with polybutylene terephthalate (6130NC010, DuPont), maleic anhydride-grafted styrene thermoplastic elastomer (FG1901, Kraton), and silica (AEROSIL®200, Degussa) in a mass ratio of 50:10:10:30.

[0095] The raw materials of the first and second surface layers were replaced with polyurethane block copolymer (TU-S5265, Kuraray), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), maleic anhydride-grafted styrene thermoplastic elastomer (FG1901, Kronen), and silica (AEROSIL® 200, Degussa) in a mass ratio of 50:10:10:30.

[0096] Example 6

[0097] This embodiment provides a waterproof and breathable membrane, the preparation method of which is basically the same as that of embodiment 3, except that the thickness of the intermediate layer, the first surface layer and the second surface layer are all 100μm.

[0098] Example 7

[0099] This embodiment provides a waterproof and breathable membrane, the preparation method of which is basically the same as that of Embodiment 3, except that the thickness of the intermediate layer is 400 μm, and the thickness of the first and second surface layers is 100 μm.

[0100] Example 8

[0101] This embodiment provides a waterproof and breathable membrane, the preparation method and composition of which are basically the same as those in Example 1. The difference is that the intermediate layer raw materials include PBT (Ultradur® B 4300 G2 BK5110, BASF), EVA (28005, LG Chem), and EVA (40W, Mitsui Chemicals) in a mass ratio of 30:40:30.

[0102] Example 9

[0103] This embodiment provides a waterproof and breathable membrane, the preparation method and composition of which are basically the same as those in Example 1. The difference is that the first and second surface layers include EVA (28005, LG Chem), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), ordinary silicate cement (AALBORG 42.5), calcium carbonate (CARB-5JI, Omia), and foaming agent masterbatch (SAFOAM FPE-20, Guangzhou Edenda) in a mass ratio of 20:40:15:24:1.

[0104] Example 10

[0105] This embodiment provides a waterproof and breathable membrane, the preparation method and composition of which are basically the same as those in Example 11. The difference is that the first and second surface layers include EVA (28005, LG Chem), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), ordinary silicate cement (AALBORG 42.5), calcium carbonate (CARB-5JI, Omia), and foaming agent masterbatch (SAFOAM FPE-20, Guangzhou Edenda) in a mass ratio of 20:40:15:24.5:0.5.

[0106] Example 11

[0107] This embodiment provides a waterproof and breathable membrane, the preparation method and composition of which are basically the same as those in Example 11. The difference is that the first and second surface layers include EVA (28005, LG Chem), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), ordinary silicate cement (AALBORG 42.5), calcium carbonate (CARB-5JI, Omia), and foaming agent masterbatch (SAFOAM FPE-20, Guangzhou Edenda) in a mass ratio of 20:40:15:22:3.

[0108] Comparative Example 1

[0109] This comparative example provides a waterproof and breathable membrane, the preparation method of which is as follows:

[0110] EVA (28005, LG Chem), ethylene-vinyl acetate copolymer (EVM50M27, Yunnan Zhengbang), ordinary silicate cement (AALBORG 42.5), and calcium carbonate (CARB-5JI, Omia) were mixed and extruded into granules according to a mass ratio of 20:40:15:25. After granulation, the mixture was extruded into a film to obtain a waterproof and breathable membrane with a thickness of 600μm.

[0111] Comparative Example 2

[0112] This comparative example provides a waterproof and breathable membrane, the preparation method of which is basically the same as that in Example 1, except that:

[0113] The intermediate layer consists of LLDPE (DFDA7042, Guangzhou Petrochemical), EVA (28005, LG Chem), EVA (40W, Mitsui Chemicals), and calcium carbonate (CARB-5JI, Omia) in a mass ratio of 30:40:10:20; the first and second surface layers consist of LLDPE (DFDA7042, Guangzhou Petrochemical) and calcium carbonate (CARB-5JI, Omia) in a mass ratio of 80:20.

[0114] Comparative Example 3

[0115] This comparative example uses commercially available DuPont 1.0mm thick aluminum alloy. TM Tyvek ® Trevez ® Windproof, waterproof, and breathable membranes are used as waterproof and breathable membranes.

[0116] Test case

[0117] The following performance tests were conducted on the waterproof and breathable membranes of the above embodiments and comparative examples:

[0118] 1. Water vapor transmission rate

[0119] Test method: The test shall be conducted at 23℃ and 90% relative humidity, in accordance with the method in GB / T 17146-2015.

[0120] 2. Bond strength with plastering mortar and putty

[0121] Test method: The test shall be conducted in accordance with GB / T 5210-2006.

[0122] 3. Impermeability

[0123] Test method: Refer to Method A of GB / T 328.7-2007 for testing.

[0124] 4. Tensile strength and elongation

[0125] Test method: Refer to method A of GB / T 328.9-2007 for testing.

[0126] 5. Heating expansion and contraction rate

[0127] Test method: Refer to GB / T 12027-2004 for testing.

[0128] Table 1

[0129]

[0130] As can be seen from Table 1:

[0131] 1) The waterproof and breathable membranes of Examples 1 to 11 of the present invention have high water vapor permeability and high bonding strength with plastering mortar and putty. They also have no leakage during application, have good waterproof performance, high tensile strength and elongation, and low thermal shrinkage rate, indicating that they have good performance. Among them, the thickness of the intermediate layer membrane in Example 7 is large, which significantly affects the water vapor permeability of the waterproof and breathable membrane, resulting in a low water vapor permeability. After adding mesh cloth to the intermediate layer, the tensile strength of the waterproof and breathable membranes in Examples 4 and 5 is significantly improved, but the elongation rate is reduced, which has no significant impact on other properties.

[0132] 2) The waterproof and breathable membrane of Comparative Example 1 lacks hydrophilic polymers, resulting in very low water vapor permeability and poor breathability. Comparative Example 2, with its surface layer lacking a polar first polymer and its middle layer lacking a hydrophilic second polymer segment, yielded a waterproof and breathable membrane that was non-sticky and also had poor breathability. Comparative Example 3 used commercially available DuPont... TM Tyvek ® Trevez ® Although windproof, waterproof, and breathable membranes have good breathability, they cannot be bonded.

[0133] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waterproof and breathable membrane, characterized in that, The waterproof and breathable membrane includes a first surface layer, a second surface layer, and an intermediate layer disposed between the first surface layer and the second surface layer; The first and second surface layers comprise a first polymer, and the intermediate layer comprises a second polymer; The first polymer contains one or more functional groups selected from carboxyl, ester, acid anhydride, or amino groups; The second polymer is a hydrophilic thermoplastic polymer.

2. The waterproof and breathable membrane according to claim 1, characterized in that, The first polymer includes one or more of polyvinyl acetate, polyethylene methyl acrylate, ethylene ethyl acrylate, ethylene butyl acrylate, polyacrylate, thermoplastic polyurethane, and maleic anhydride-grafted polyolefin.

3. The waterproof and breathable membrane according to claim 1 or 2, characterized in that, The second polymer includes one or more of polyether segments, polyacrylic acid segments, polyurethane segments, polyvinyl alcohol segments, polyamide segments, and polyester segments; Preferably, the second polymer comprises one or more of polyvinyl alcohol, polycaprolactam, polyvinyl acetate, polyurethane, polybutylene terephthalate, and polylactic acid.

4. The waterproof and breathable membrane according to any one of claims 1-3, characterized in that, In the first and second surface layers, the mass content of the first polymer is not less than 35%, preferably 40% to 80%; And / or, in the intermediate layer, the mass content of the second polymer is not less than 50%, preferably 50% to 90%.

5. The waterproof and breathable membrane according to any one of claims 1-3, characterized in that, The first and second surface layers further include a first inorganic filler; Preferably, the first inorganic filler includes one or more of calcium carbonate, silicon dioxide, wollastonite, aluminum hydroxide, silicate cement, and diatomaceous earth.

6. The waterproof and breathable membrane according to claim 5, characterized in that, The mass content of the first inorganic filler in the first and second surface layers is 20% to 60%.

7. The waterproof and breathable membrane according to any one of claims 1-6, characterized in that, The intermediate layer also includes a second inorganic filler; Preferably, the second inorganic filler includes one or more of silica, wollastonite, sepiolite, montmorillonite, and calcium carbonate.

8. The waterproof and breathable membrane according to claim 7, characterized in that, The mass content of the second inorganic filler in the intermediate layer is no higher than 40%.

9. The waterproof and breathable membrane according to any one of claims 1-8, characterized in that, The first and second surface layers have a porous structure.

10. The waterproof and breathable membrane according to any one of claims 1-9, characterized in that, The intermediate layer further includes a mesh fabric, and the second polymer is loaded onto the surface of the mesh fabric; Preferably, the mesh size of the mesh fabric is no greater than 8mm × 8mm.

11. The waterproof and breathable membrane according to any one of claims 1-10, characterized in that, The thickness of the first and second surface layers is 100~400μm; And / or, the thickness of the intermediate layer is 150μm~500μm.

12. The waterproof and breathable membrane according to any one of claims 1-11, characterized in that, The water vapor permeability of the waterproof and breathable membrane is ≥100 g / m² per 24 hours. 2 ; The bonding strength between the waterproof and breathable membrane and the plastering mortar or putty is ≥0.4MPa.

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