Waterproof TPU film

Abstract

The invention relates to a waterproof TPU (thermoplastic polyurethane) film, and relates to the field of film materials, and the waterproof TPU film is prepared from the following raw materials in parts by mass: 80-100 parts of polyurethane resin, 10-20 parts of a compatible modifier, 5-10 parts of waterproof moisture-permeable filler, 0.5-1.5 parts of an antioxidant, 0.4-0.8 part of a light stabilizer and 0.5-1 part of a lubricant, the polyurethane resin is prepared by the following steps: dehydrating polytetrahydrofuran ether glycol, adding 4, 4 '-diphenylmethane diisocyanate in a protective atmosphere, heating and stirring to react, adding 1, 4-butanediol and a catalyst under a stirring condition, curing, granulating and drying to obtain the polyurethane resin. The waterproof and moisture permeable TPU film has the effect of improving the waterproof and moisture permeable performance of the TPU film, and the film has good tensile property.

Description

Technical Field

[0001] This application relates to the field of thin film materials, and in particular to a waterproof TPU film. Background Technology

[0002] Significant progress has been made in the development of thin film materials, especially in functional thin films. As people's demands for product performance continue to increase, functional thin films are playing an increasingly important role in many industries. For example, in industries such as clothing, construction, and electronics, the demand for thin films with special properties is growing. These films not only need to meet basic physical properties but also need to possess specific functions such as waterproofing and breathability to adapt to different application scenarios, bringing new opportunities and changes to the development of various industries.

[0003] There are several conventional methods used in existing technologies to address the issue of waterproofing and breathability of membranes. One common method is to use ordinary plastic film, which has some waterproofing properties but poor breathability, making it difficult to meet the needs of applications requiring high breathability. Another method is to use a coating, applying a waterproof coating to the surface of the membrane to enhance its waterproofing ability, but this coating may affect the membrane's flexibility and durability. Additionally, a multi-layer composite method can be used, combining membranes with different properties to achieve both waterproofing and breathability. However, this composite method is often complex, costly, and prone to problems with weak interlayer bonding during the lamination process.

[0004] However, these existing technologies have significant drawbacks. Ordinary plastic films have poor air permeability, which cannot meet the needs of some applications that require timely removal of moisture; coated films have poor flexibility and durability, and are prone to problems such as coating peeling during use; multilayer composite film processes are complex and costly, and weak interlayer bonding may lead to unstable film performance, so improvements are needed. Summary of the Invention

[0005] To improve the waterproof and breathable properties of the film, this application provides a waterproof TPU film.

[0006] The waterproof TPU film provided in this application adopts the following technical solution:

[0007] A waterproof TPU film, the raw materials for which are prepared include the following components in parts by weight:

[0008] 80-100 parts of polyurethane resin

[0009] 10-20 parts of compatibility modifier

[0010] 5-10 parts of waterproof and breathable filler

[0011] Antioxidant 0.5-1.5 parts

[0012] Light stabilizer 0.4-0.8 parts

[0013] Lubricant 0.5-1 part;

[0014] The polyurethane resin is prepared using the following steps:

[0015] Polytetrahydrofuran ether diol was dehydrated, and 4,4'-diphenylmethane diisocyanate was added under a protective atmosphere. The mixture was heated and stirred to react. 1,4-butanediol and a catalyst were added under stirring conditions. The mixture was then cured, pelletized, and dried to obtain polyurethane resin.

[0016] The waterproof and breathable properties, as well as the tensile properties, of TPU films are improved by using a composite system of polyurethane resin, compatibility modifier, and functional filler. The polyurethane resin itself can form a dense microphase separation structure of soft and hard segments, providing the material with basic elasticity and a certain degree of barrier properties. The introduced compatibility modifier helps to improve the interfacial bonding between the filler and the resin matrix, allowing the waterproof and breathable filler to be more uniformly dispersed and to construct a suitable microscopic path for water vapor to pass through but blocking liquid water within the film. This effectively improves the waterproof and breathable properties of the film while maintaining its mechanical integrity.

[0017] Preferably, the polytetrahydrofuran ether diol is prepared by modification using the following steps:

[0018] Under a protective atmosphere, polytetrahydrofuran ether diol was mixed with ethyl acetate, heated, and 3-glycidyl etheroxypropyltrimethoxysilane and a catalyst were added. The mixture was stirred and reacted. Then, 3,3,3-trifluoro-1-propanol and a catalyst were added, and the mixture was stirred and reacted. The mixture was cooled, purified, and dried to obtain modified polytetrahydrofuran ether diol.

[0019] By chemically grafting polytetrahydrofuran ether diol, fluorinated hydrophobic segments and siloxane bridging structures are introduced into its molecular chain. This modification can promote the formation of a more regular microphase separation morphology between the hard and soft segments of polyurethane during subsequent polymerization. The fluorinated segments impart lower interfacial energy to the material surface to improve water resistance, while the introduction of siloxane units helps to enhance the crosslinking density and interfacial compatibility between molecular chains. Thus, while maintaining the moisture permeability channel structure of the film, it synergistically improves its tensile strength and long-term stability.

[0020] Preferably, the mass ratio of the polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is (0.95-1.05):0.2:0.3.

[0021] By limiting the mass ratio of polytetrahydrofuran ether diol, epoxy-containing silane, and perfluorool, the modified polyol molecular chains can maintain flexibility while achieving a balanced distribution of fluorinated segments and siloxane structures through controllable grafting density. This orderly regulation at the molecular level helps to form a more stable microphase separation structure during subsequent film formation. The hydrophobic regions formed by the aggregation of fluorinated segments can improve the hydrostatic pressure resistance of the film, while the appropriate cross-linking structure and the optimization of the ratio of soft and hard segments are conducive to maintaining the moisture permeability channels and enhancing the interaction between molecular chains, thereby achieving a synergistic improvement in both the moisture permeability and mechanical strength of the material.

[0022] Preferably, the compatibility modifier is prepared using the following steps:

[0023] Under a protective atmosphere, butyl acrylate, methyl methacrylate, and perfluorooctyl ethyl methacrylate were added to a solvent, along with maleic anhydride and a catalyst, to obtain a mixture. The mixture was heated and stirred to react. After the reaction was completed, the mixture was settled, filtered, washed, dried, melt-granulated, and then the compatibility modifier was obtained.

[0024] By designing fluorinated acrylate copolymers as compatibility modifiers, flexible segments, rigid units, fluorinated hydrophobic groups, and acid anhydride reactive functional groups are introduced into their molecular chains. This multi-component synergistic effect enables the modifier to form an interface bond with the polyurethane molecular chains through the acid anhydride groups. The flexible segments help maintain the elasticity of the material, the fluorinated side chains migrate to the surface to build a hydrophobic layer, and the rigid units enhance the interfacial anchoring strength. This improves the dispersibility of the filler while forming a stable interfacial transition layer, which helps to coordinate the balance between the moisture permeability channel structure and mechanical properties of the material.

[0025] Preferably, the mass ratio of butyl acrylate, methyl methacrylate and perfluorooctyl ethyl methacrylate is 1:0.7:(0.09-0.27).

[0026] By adjusting the mass ratio of butyl acrylate, methyl methacrylate, and fluorinated monomers, the synthesized compatibility modifier achieves a balanced configuration of flexible skeleton, rigid units, and hydrophobic groups in its molecular chain structure. This design enables the modifier to achieve good compatibility with polyurethane soft segments in the interfacial region through flexible chain segments, while also enhancing interfacial anchoring through rigid units. At the same time, the fluorinated side chains form an orderly hydrophobic layer on the material surface, thereby improving filler dispersibility and interfacial bonding while synergistically enhancing the material's hydrostatic pressure resistance and tensile properties.

[0027] Preferably, the amount of maleic anhydride used accounts for 8-10% of the mass of butyl acrylate.

[0028] By controlling the proportion of maleic anhydride in butyl acrylate, the synthesized compatibility modifier can form an anhydride functional group distribution of appropriate density on the molecular chain. These anhydride groups can form hydrogen bond interactions with the polyurethane molecular chain and establish interfacial connections. While improving the dispersibility of the filler, the interfacial bonding strength is enhanced through appropriate intermolecular forces, so that the material can maintain its flexibility while improving its mechanical strength, and is conducive to maintaining the structural stability of the moisture permeability channel.

[0029] Preferably, the waterproof and breathable filler comprises metal-organic framework material ZIF-8 and hydrophobic nano-silica.

[0030] By combining the metal-organic framework material ZIF-8 with hydrophobic nano-silica as a waterproof and breathable filler, the regular microporous structure of ZIF-8 provides selective permeation channels for water vapor molecules. At the same time, the hydrophobic properties contributed by the surface microstructure constructed by ZIF-8 and hydrophobic nano-silica help to improve the water pressure resistance of the film. In addition, the physical filling of these two fillers in the polyurethane resin matrix can adjust the stress distribution inside the material, thereby synergistically improving the tensile properties of the film.

[0031] Preferably, the mass ratio of the metal-organic framework material ZIF-8 to hydrophobic nano-silica is 1:(0.5-0.7).

[0032] By controlling the mass ratio of metal-organic framework material ZIF-8 to hydrophobic nano-silica, the two materials form a complementary distribution pattern in the polyurethane matrix: the regular pore structure of ZIF-8 provides a pathway for water molecule transport, while an appropriate amount of hydrophobic nano-silica maintains the hydrophobicity of the system and moderately enhances the interaction between the filler and the matrix interface, thus maintaining a reasonable moisture permeability channel inside the material and having a positive regulatory effect on mechanical properties, thereby synergistically optimizing the overall performance of the film.

[0033] In summary, this application includes at least one of the following beneficial technical effects:

[0034] The waterproof and breathable properties, as well as the tensile properties, of TPU films are improved by using a composite system of polyurethane resin, compatibility modifier, and functional filler. The polyurethane resin itself can form a dense microphase separation structure of soft and hard segments, providing the material with basic elasticity and a certain degree of barrier properties. The introduced compatibility modifier helps to improve the interfacial bonding between the filler and the resin matrix, allowing the waterproof and breathable filler to be more uniformly dispersed and to construct a suitable microscopic path for water vapor to pass through but blocking liquid water within the film. This effectively improves the waterproof and breathable properties of the film while maintaining its mechanical integrity.

[0035] By chemically grafting polytetrahydrofuran ether diol, fluorinated hydrophobic segments and siloxane bridging structures are introduced into its molecular chain. This modification can promote the formation of a more regular microphase separation morphology between the hard and soft segments of polyurethane during subsequent polymerization. The fluorinated segments impart lower interfacial energy to the material surface to improve water resistance, while the introduction of siloxane units helps to enhance the crosslinking density and interfacial compatibility between molecular chains. Thus, while maintaining the moisture permeability channel structure of the film, it synergistically improves its tensile strength and long-term stability.

[0036] By designing fluorinated acrylate copolymers as compatibility modifiers, flexible segments, rigid units, fluorinated hydrophobic groups, and acid anhydride reactive functional groups are introduced into their molecular chains. This multi-component synergistic effect enables the modifier to form an interface bond with the polyurethane molecular chains through the acid anhydride groups. The flexible segments help maintain the elasticity of the material, the fluorinated side chains migrate to the surface to build a hydrophobic layer, and the rigid units enhance the interfacial anchoring strength. This improves the dispersibility of the filler while forming a stable interfacial transition layer, which helps to coordinate the balance between the moisture permeability channel structure and mechanical properties of the material. Detailed Implementation

[0037] This application discloses a waterproof TPU film. Unless otherwise specified, all raw materials used in this application are commercially available. The following detailed description, in conjunction with embodiments, further illustrates this application:

[0038] Raw material description: Polytetrahydrofuran ether diol was purchased from Guangzhou Haoyi New Material Technology Co., Ltd.; 4,4'-diphenylmethane diisocyanate (CAS No.: 101-68-8); 1,4-butanediol (CAS No.: 110-63-4); stannous octoate (CAS No.: 301-10-0); butyl acrylate (CAS No.: 141-32-2); methyl methacrylate (CAS No.: 80-62-6); perfluorooctyl ethyl methacrylate (CAS No.: 1996-88-9); maleic anhydride (CAS No.: 108-31-6); benzoyl peroxide (CAS No.: 94-36). -0), metal-organic framework material ZIF-8 was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., hydrophobic nano silica model HB-139 was purchased from Hubei Huifu Nanomaterials Co., Ltd., antioxidant 1010 was purchased from Jiangsu Xinluda Polymer Materials Co., Ltd., UV-234 was purchased from Nanjing Milan Chemical Co., Ltd., calcium stearate was purchased from Dongguan Nuojia Plastics Co., Ltd., 3-glycidyl etheroxypropyltrimethoxysilane (CAS No.: 2530-83-8), 3,3,3-trifluoro-1-propanol (CAS No.: 2240-88-2), triphenylphosphine (CAS No.: 603-35-0).

[0039] Example 1

[0040] Preparation of polyurethane resin

[0041] The mass ratio of polytetrahydrofuran ether diol, 4,4'-diphenylmethane diisocyanate, 1,4-butanediol and catalyst is 1:0.38:0.09:0.001.

[0042] Polytetrahydrofuran ether diol was dehydrated at 110°C and under a vacuum of <-0.095 MPa for 2 hours, then cooled to 80°C. Under a nitrogen atmosphere, 4,4'-diphenylmethane diisocyanate was added, and the mixture was stirred at 200 rpm at 80°C for 2 hours. The mixture was then cooled to 70°C, and 1,4-butanediol and a catalyst (stannous octoate) were added while stirring at 800 rpm. After stirring for 3 minutes, the mixture was heated to 100°C and matured for 5 hours under a dry nitrogen atmosphere. The mixture was then pelletized and dried under vacuum at 80°C to obtain polyurethane resin.

[0043] Preparation of compatibility modifiers

[0044] The mass ratio of butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride and catalyst is 1:0.7:0.09, and the amount of maleic anhydride accounts for 8% of the mass of butyl acrylate.

[0045] Under a nitrogen protective atmosphere, butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride, and catalyst (benzoyl peroxide, 0.5% of the total monomer mass) were added to a solvent (ethyl acetate) to obtain a mixture with a solid content of 45%. The mixture was stirred at 250 rpm for 7 h at 80 °C. After the reaction was completed, it was poured into ethanol to settle, filtered, washed with ethanol, dried under vacuum at 70 °C, and melt-granulated at 170 °C to obtain a compatibility modifier.

[0046] Preparation of waterproof TPU film

[0047] Weigh out 80 parts of polyurethane resin, 10 parts of compatibility modifier, 5 parts of waterproof and breathable filler, 0.5 parts of antioxidant, 0.4 parts of light stabilizer, and 0.5 parts of lubricant. The waterproof and breathable filler is composed of metal-organic framework material ZIF-8 and hydrophobic nano-silica in a mass ratio of 1:0.5. The antioxidant is antioxidant 1010, the light stabilizer is UV-234, and the lubricant is calcium stearate.

[0048] Polyurethane resin, compatibility modifier, waterproof and breathable filler, antioxidant, light stabilizer and lubricant are mixed and premixed at 500 rpm for 5 min at 45℃. The mixture is then transferred to a twin-screw extruder for melt blending at 185-195℃. After water cooling and pelletizing, the mixture is vacuum dried at 80℃ to obtain masterbatch. The masterbatch is fed into a blown film machine and melt-plasticized at 190℃. The blow-up ratio is controlled at 3.0 and the traction rate is 10 m / min. After cooling and winding, a waterproof TPU film is obtained.

[0049] Example 2

[0050] Preparation of polyurethane resin

[0051] The mass ratio of polytetrahydrofuran ether diol, 4,4'-diphenylmethane diisocyanate, 1,4-butanediol and catalyst is 1:0.38:0.09:0.001.

[0052] Polytetrahydrofuran ether diol was dehydrated at 110°C and under a vacuum of <-0.095 MPa for 2 hours, then cooled to 80°C. Under a nitrogen atmosphere, 4,4'-diphenylmethane diisocyanate was added, and the mixture was stirred at 200 rpm at 80°C for 2 hours. The mixture was then cooled to 70°C, and 1,4-butanediol and a catalyst (stannous octoate) were added while stirring at 800 rpm. After stirring for 3 minutes, the mixture was heated to 100°C and matured for 5 hours under a dry nitrogen atmosphere. The mixture was then pelletized and dried under vacuum at 80°C to obtain polyurethane resin.

[0053] Preparation of compatibility modifiers

[0054] The mass ratio of butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride and catalyst is 1:0.7:0.27, and the amount of maleic anhydride is 10% of the mass of butyl acrylate.

[0055] Under a nitrogen protective atmosphere, butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride, and catalyst (benzoyl peroxide, 0.5% of the total monomer mass) were added to a solvent (ethyl acetate) to obtain a mixture with a solid content of 45%. The mixture was stirred at 250 rpm for 7 h at 80 °C. After the reaction was completed, it was poured into ethanol to settle, filtered, washed with ethanol, dried under vacuum at 70 °C, and melt-granulated at 170 °C to obtain a compatibility modifier.

[0056] Preparation of waterproof TPU film

[0057] Weigh 100 parts of polyurethane resin, 20 parts of compatibility modifier, 10 parts of waterproof and breathable filler, 1.5 parts of antioxidant, 0.8 parts of light stabilizer, and 1 part of lubricant; the waterproof and breathable filler is composed of metal-organic framework material ZIF-8 and hydrophobic nano-silica in a mass ratio of 1:0.7; the antioxidant is antioxidant 1010, the light stabilizer is UV-234, and the lubricant is calcium stearate.

[0058] Polyurethane resin, compatibility modifier, waterproof and breathable filler, antioxidant, light stabilizer and lubricant are mixed and premixed at 500 rpm for 5 min at 45℃. The mixture is then transferred to a twin-screw extruder for melt blending at 185-195℃. After water cooling and pelletizing, the mixture is vacuum dried at 80℃ to obtain masterbatch. The masterbatch is fed into a blown film machine and melt-plasticized at 190℃. The blow-up ratio is controlled at 3.0 and the traction rate is 10 m / min. After cooling and winding, a waterproof TPU film is obtained.

[0059] Example 3

[0060] Preparation of polyurethane resin

[0061] The mass ratio of polytetrahydrofuran ether diol, 4,4'-diphenylmethane diisocyanate, 1,4-butanediol and catalyst is 1:0.38:0.09:0.001.

[0062] Polytetrahydrofuran ether diol was dehydrated at 110°C and under a vacuum of <-0.095 MPa for 2 hours, then cooled to 80°C. Under a nitrogen atmosphere, 4,4'-diphenylmethane diisocyanate was added, and the mixture was stirred at 200 rpm at 80°C for 2 hours. The mixture was then cooled to 70°C, and 1,4-butanediol and a catalyst (stannous octoate) were added while stirring at 800 rpm. After stirring for 3 minutes, the mixture was heated to 100°C and matured for 5 hours under a dry nitrogen atmosphere. The mixture was then pelletized and dried under vacuum at 80°C to obtain polyurethane resin.

[0063] Preparation of compatibility modifiers

[0064] The mass ratio of butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride and catalyst is 1:0.7:0.18, and the amount of maleic anhydride accounts for 9% of the mass of butyl acrylate.

[0065] Under a nitrogen protective atmosphere, butyl acrylate, methyl methacrylate, perfluorooctyl ethyl methacrylate, maleic anhydride, and catalyst (benzoyl peroxide, 0.5% of the total monomer mass) were added to a solvent (ethyl acetate) to obtain a mixture with a solid content of 45%. The mixture was stirred at 250 rpm for 7 h at 80 °C. After the reaction was completed, it was poured into ethanol to settle, filtered, washed with ethanol, dried under vacuum at 70 °C, and melt-granulated at 170 °C to obtain a compatibility modifier.

[0066] Preparation of waterproof TPU film

[0067] Weigh out 90 parts of polyurethane resin, 15 parts of compatibility modifier, 7.5 parts of waterproof and breathable filler, 1 part of antioxidant, 0.6 parts of light stabilizer, and 0.75 parts of lubricant. The waterproof and breathable filler is composed of metal-organic framework material ZIF-8 and hydrophobic nano-silica in a mass ratio of 1:0.6. The antioxidant is antioxidant 1010, the light stabilizer is UV-234, and the lubricant is calcium stearate.

[0068] Polyurethane resin, compatibility modifier, waterproof and breathable filler, antioxidant, light stabilizer and lubricant are mixed and premixed at 500 rpm for 5 min at 45℃. The mixture is then transferred to a twin-screw extruder for melt blending at 185-195℃. After water cooling and pelletizing, the mixture is vacuum dried at 80℃ to obtain masterbatch. The masterbatch is fed into a blown film machine and melt-plasticized at 190℃. The blow-up ratio is controlled at 3.0 and the traction rate is 10 m / min. After cooling and winding, a waterproof TPU film is obtained.

[0069] Example 4

[0070] Example 4 is based on Example 3. The only difference between Example 4 and Example 3 is that the polytetrahydrofuran ether diol used in the preparation of polyurethane resin in Example 4 has been modified. It is prepared using the following steps:

[0071] The mass ratio of polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is 0.95:0.2:0.3.

[0072] Under a nitrogen protective atmosphere, dehydrated polytetrahydrofuran ether diol (120℃, -0.1MPa, 2h) was mixed with anhydrous ethyl acetate, heated to 110℃, and 3-glycidyl etheroxypropyltrimethoxysilane and catalyst (triphenylphosphine, 1.5% of the mass of polytetrahydrofuran ether diol) were added dropwise over 1h. The mixture was stirred at 200 rpm for 5h, cooled to 80℃, and stirred at 5200 rpm for 5h. After cooling, the mixture was purified by precipitation in ice-cold ethanol and dried under vacuum at 80℃ to obtain modified polytetrahydrofuran ether diol.

[0073] Example 5

[0074] Example 5 is based on Example 4. The only difference between Example 5 and Example 4 is that in Example 5, the mass ratio of polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is 1.05:0.2:0.3.

[0075] Example 6

[0076] Example 6 is based on Example 4. The only difference between Example 6 and Example 4 is that in Example 6, the mass ratio of polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is 1:0.2:0.3.

[0077] Example 7

[0078] Example 7 is based on Example 4. The only difference between Example 7 and Example 4 is that in Example 7, the mass ratio of polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is 0.9:0.2:0.3.

[0079] Example 8

[0080] Example 8 is based on Example 4. The only difference between Example 8 and Example 4 is that in Example 8, the mass ratio of polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is 1.1:0.2:0.3.

[0081] Example 9

[0082] Example 9 is based on Example 3. The only difference between Example 9 and Example 3 is that in Example 9, the mass ratio of butyl acrylate, methyl methacrylate and perfluorooctyl ethyl methacrylate is 1:0.7:0.05 when preparing the compatibility modifier.

[0083] Example 10

[0084] Example 10 is based on Example 3. The only difference between Example 10 and Example 3 is that in Example 10, the mass ratio of butyl acrylate, methyl methacrylate and perfluorooctyl ethyl methacrylate is 1:0.7:0.35 when preparing the compatibility modifier.

[0085] Example 11

[0086] Example 11 is based on Example 3. The only difference between Example 11 and Example 3 is that the amount of maleic anhydride used in the preparation of the compatibility modifier in Example 11 is 6% of the mass of butyl acrylate.

[0087] Example 12

[0088] Example 12 is based on Example 3. The only difference between Example 12 and Example 3 is that the amount of maleic anhydride used in the preparation of the compatibility modifier in Example 12 is 12% of the mass of butyl acrylate.

[0089] Example 13

[0090] Example 13 is based on Example 3. The only difference between Example 13 and Example 3 is that in Example 13, the waterproof and breathable filler is composed of metal-organic framework material ZIF-8 and hydrophobic nano-silica in a mass ratio of 1:0.3.

[0091] Example 14

[0092] Example 14 is based on Example 3. The only difference between Example 14 and Example 3 is that in Example 14, the waterproof and breathable filler is composed of metal-organic framework material ZIF-8 and hydrophobic nano-silica in a mass ratio of 1:0.9.

[0093] Comparative Example 1

[0094] Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that no compatibility modifier is added when preparing the waterproof TPU film in Comparative Example 1.

[0095] Performance testing

[0096] (1) The standard “T / SHPTA076-2024 Waterproof and breathable thermoplastic polyurethane film” was selected. The hydrostatic pressure resistance and water vapor permeability of the samples were tested. Each sample was tested three times, and the average value was taken after measurement. The results were recorded in Table 1.

[0097] (2) The tensile strength of the specimens was tested by taking GB / T 1040.3-2008 Determination of tensile properties of plastics Part 3: Test conditions for films and sheets as the standard. Each specimen was tested three times, and the average value was taken after measurement. The results were recorded in Table 1.

[0098] Table 1. Test results of waterproof and breathable properties and tensile properties Test results Hydrostatic pressure resistance (kPa) Moisture permeability (g / (m²·24h)) Tensile strength (MPa) Example 1 132 5682 27.5 Example 2 139 5815 28.4 Example 3 145 5940 29.2 Example 4 158 5943 30.8 Example 5 156 5910 30.5 Example 6 160 5935 31.7 Example 7 153 5890 30.0 Example 8 155 5920 30.4 Example 9 130 6100 25.3 Example 10 152 5805 25.6 Example 11 141 5965 25.0 Example 12 148 5912 26.5 Example 13 137 6119 25.5 Example 14 154 5744 26.8 Comparative Example 1 110 5285 23.1

[0099] As shown in Table 1, the hydrostatic pressure resistance of Examples 1-3 is greater than 132 kPa, the moisture permeability is greater than 5682 g / (m²·24h), and the tensile strength is greater than 27.5 MPa. This demonstrates that the waterproof TPU membrane prepared in this application has good waterproof and moisture permeability as well as tensile properties.

[0100] As shown in Table 1, the only difference between Examples 4-8 and Example 3 is that: in Examples 4-6, polytetrahydrofuran ether diol was modified within a limited ratio range, which effectively improved its waterproof and tensile properties, while maintaining good moisture permeability; in Examples 7 and 8, the limited ratio was disrupted, resulting in a decrease in the performance improvement effect.

[0101] As shown in Table 1, the only difference between Examples 9 and 10 and Example 3 is that the limited ratio of the compatibility modifier in Examples 9 and 10 was disrupted. Too much or too little fluorinated monomer will affect hydrophobicity and compatibility, and thus affect the balance between waterproof and breathable properties and tensile properties.

[0102] As shown in Table 1, the only difference between Examples 11 and 12 and Example 3 is that the specified ratio of maleic anhydride added during the preparation of the compatibility modifier was broken in Examples 11 and 12. Too little maleic anhydride will affect the interfacial bonding, while too much maleic anhydride will affect the moisture permeability.

[0103] As shown in Table 1, the only difference between Examples 13 and 14 and Example 3 is that the specified ratio of waterproof and breathable filler was disrupted in Examples 13 and 14, which affected the balance between the waterproof and breathable properties of the TPU film, resulting in a decrease in performance.

[0104] As shown in Table 1, the only difference between Comparative Example 1 and Example 3 is that no compatibility modifier was added in Comparative Example 1, resulting in a significant decrease in the dispersibility and compatibility between the components, and a noticeable impact on performance.

[0105] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A waterproof TPU film, characterized in that: The raw materials for preparation include the following components in parts by mass: 80-100 parts of polyurethane resin 10-20 parts of compatibility modifier 5-10 parts of waterproof and breathable filler Antioxidant 0.5-1.5 parts Light stabilizer 0.4-0.8 parts Lubricant 0.5-1 part; The polyurethane resin is prepared using the following steps: Polytetrahydrofuran ether diol was dehydrated, and 4,4'-diphenylmethane diisocyanate was added under a protective atmosphere. The mixture was heated and stirred to react. 1,4-butanediol and a catalyst were added under stirring conditions. The mixture was then cured, pelletized, and dried to obtain polyurethane resin.

2. The waterproof TPU film according to claim 1, characterized in that: The polytetrahydrofuran ether diol was prepared by the following steps after modification: Under a protective atmosphere, polytetrahydrofuran ether diol was mixed with ethyl acetate, heated, and 3-glycidyl etheroxypropyltrimethoxysilane and a catalyst were added. The mixture was stirred and reacted. Then, 3,3,3-trifluoro-1-propanol and a catalyst were added, and the mixture was stirred and reacted. The mixture was cooled, purified, and dried to obtain modified polytetrahydrofuran ether diol.

3. The waterproof TPU film according to claim 2, characterized in that: The mass ratio of the polytetrahydrofuran ether diol, 3-glycidyl etheroxypropyltrimethoxysilane and 3,3,3-trifluoro-1-propanol is (0.95-1.05):0.2:0.

3.

4. The waterproof TPU film according to claim 1, characterized in that: The compatibility modifier is prepared using the following steps: Under a protective atmosphere, butyl acrylate, methyl methacrylate, and perfluorooctyl ethyl methacrylate were added to a solvent, along with maleic anhydride and a catalyst, to obtain a mixture. The mixture was heated and stirred to react. After the reaction was completed, the mixture was settled, filtered, washed, dried, melt-granulated, and then the compatibility modifier was obtained.

5. A waterproof TPU film according to claim 4, characterized in that: The mass ratio of butyl acrylate, methyl methacrylate and perfluorooctyl ethyl methacrylate is 1:0.7:(0.09-0.27).

6. The waterproof TPU film according to claim 5, characterized in that: The amount of maleic anhydride used is 8-10% of the mass of butyl acrylate.

7. The waterproof TPU film according to claim 1, characterized in that: The waterproof and breathable filler includes metal-organic framework material ZIF-8 and hydrophobic nano-silica.

8. The waterproof TPU film according to claim 7, characterized in that: The mass ratio of the metal-organic framework material ZIF-8 to the hydrophobic nano-silica is 1:(0.5-0.7).