Waterproof and breathable membrane with thermal insulation function

Abstract

The application belongs to the technical field of waterproof membranes, and specifically discloses a waterproof and breathable membrane with heat insulation function. The waterproof and breathable membrane with heat insulation function comprises a base layer, a heat insulation layer and an outer layer arranged in sequence. The heat insulation layer comprises the following raw materials in parts by weight: polyurethane acrylate 100-120 parts, aluminum oxide 25-30 parts, silver oxide 15-25 parts, modified bentonite 30-50 parts, nano titanium dioxide 15-18 parts, coupling agent 5-8 parts and dispersing agent 5-8 parts. The waterproof and breathable membrane with heat insulation function prepared in the application has good tensile strength, tear resistance and elongation at break under the premise of ensuring good heat insulation performance.

Description

Technical Field

[0001] This application relates to the technical field of waterproof membranes, and in particular to a waterproof and breathable membrane with heat insulation function. Background Technology

[0002] Waterproof and breathable membranes are a type of high-molecular waterproof material, typically made of polyvinyl chloride, polypropylene, polyethylene, polystyrene, and other resins into thin films. They are used for packaging and as a coating layer and have been widely applied in footwear, clothing, food, pharmaceuticals, chemicals, and other fields, bringing great convenience to people's lives.

[0003] Currently used heat insulation films generally employ an aluminum plating process, which involves plating a layer of metallic aluminum onto the surface of the film to achieve a high-efficiency heat insulation effect. However, in actual use, the metallic aluminum plating on the film surface is prone to tearing or breaking during the film stretching process, thus affecting the overall heat insulation effect of the film. Therefore, there is an urgent need to research a waterproof and breathable membrane with good mechanical properties and heat insulation function. Summary of the Invention

[0004] To improve the poor mechanical properties of aluminized heat-insulating films, this application provides a waterproof and breathable membrane with heat insulation function.

[0005] This application provides a waterproof and breathable membrane with heat insulation function, using the following technical solution:

[0006] A waterproof and breathable membrane with heat insulation function includes a base layer, a heat insulation layer and an outer layer arranged sequentially.

[0007] The heat insulation layer comprises the following raw materials in parts by weight: 100-120 parts of polyurethane acrylate, 25-30 parts of alumina, 15-25 parts of silver oxide, 30-50 parts of modified bentonite, 15-18 parts of nano titanium dioxide, 5-8 parts of coupling agent and 5-8 parts of dispersant.

[0008] By adopting the above technical solutions, polyurethane acrylate has excellent wear resistance, flexibility, and high elongation at break. It also has good high and low temperature resistance and good adhesion. As a thermal insulation layer, it has excellent comprehensive performance. The non-flammability and low density of alumina and silver oxide give it high temperature resistance, thermal shock resistance, and high mechanical strength. At the same time, it can increase the viscosity of the thermal insulation layer system, so that the thermal insulation layer has good thermal insulation and mechanical strength.

[0009] Modified bentonite has a large specific surface area and good adsorption properties, enabling it to adsorb alumina, silver oxide, and nano-titanium dioxide. Furthermore, modified bentonite itself possesses excellent thermal insulation and moisture-regulating properties, thereby increasing the thermal insulation performance of the insulation layer system. It also enhances the insulation layer's antioxidant capacity, UV radiation resistance, and stability. Nano-titanium dioxide has antibacterial, deodorizing, thermal insulation, and antifouling properties. When nano-titanium dioxide is loaded onto the surface and within the pores of modified bentonite, it further increases the specific surface area of ​​the modified bentonite, thus further improving the thermal insulation performance of the insulation layer.

[0010] Preferably, the method for preparing the heat insulation layer includes the following steps:

[0011] (1) Disperse the modified bentonite in anhydrous ethanol, then add alumina, silver oxide, nano titanium dioxide and dispersant, stir for 1-2 hours in an inert gas environment at 85-90℃, and dry to obtain a mixture;

[0012] (2) Mix the mixture obtained in step (1) with polyurethane acrylate and coupling agent and stir for 3-5 hours, then heat to 260-280℃, extrude, cool and slice to obtain heat insulation masterbatch;

[0013] (3) Press the heat insulation masterbatch obtained in step (3) into a film, cool it, eliminate static electricity, roll it up and cut it to obtain the heat insulation layer.

[0014] By adopting the above technical solution, the modified bentonite has a porous and ordered structure. Alumina, silver oxide, and nano-titanium dioxide are uniformly loaded on the surface or in the pore structure of the modified bentonite. The dispersant helps to uniformly disperse alumina, silver oxide, and nano-titanium dioxide, and also helps to uniformly load each component on the surface of the modified bentonite. The modified bentonite has good adsorption, heat insulation, antibacterial and thickening properties, while alumina, silver oxide, and nano-titanium dioxide all have good heat insulation performance. The modified bentonite loaded with alumina, silver oxide, and nano-titanium dioxide further increases the heat insulation performance of the modified bentonite.

[0015] First, modified bentonite, alumina, silver oxide, and nano-titanium dioxide are mixed. Then, polyurethane acrylate and coupling agent are added and stirred to ensure that all raw material components are mixed evenly. The mixture is then extruded and sliced ​​to obtain a heat insulation masterbatch. The prepared heat insulation masterbatch is then wound up and slit to obtain a heat insulation layer. The preparation method is simple, the operation steps are simple, and a heat insulation layer with good comprehensive performance is obtained.

[0016] Preferably, the method for preparing the modified bentonite includes the following steps:

[0017] (1) Crush the bentonite, then soak it in potassium hydroxide solution for 1-3 hours, then wash it with water, disperse the treated bentonite in deionized water, and then add sodium carbonate and sodium cellulose in a mass ratio of 1:1-3. Stir at 200-220℃ for 3-5 hours to obtain sodium-based bentonite.

[0018] (2) Add graphene oxide and bamboo charcoal fiber to the sodium-based bentonite obtained in step (1), and stir at 80-85℃ for 10-12 hours to obtain a mixture;

[0019] (3) Add konjac glucomannan to the mixture obtained in step (2), stir at 50-60℃ for 10-15 min at a stirring rate of 1500-1800 r / min, dry at 80-90℃ for 5-6 h, and cool to room temperature to obtain modified bentonite.

[0020] By adopting the above technical solution, bentonite is first soaked in potassium hydroxide solution. The potassium hydroxide solution erodes the bentonite to a certain extent, increasing the pore size of the bentonite and thus increasing the specific surface area of ​​the bentonite, which helps the loading of subsequent components. At the same time, the potassium hydroxide solution can increase the sodium content and improve the dispersibility of bentonite. Then, sodium carbonate and sodium cellulose are added to prepare sodium-based bentonite. Sodium-based bentonite has good viscosity, air permeability and thermal stability. It is then used as a filler in the insulation layer to increase the air permeability and heat insulation performance of the insulation layer.

[0021] Graphene oxide has good mechanical properties, thermal insulation properties, air permeability and chemical stability, while bamboo charcoal fiber has better air permeability, antibacterial properties, adsorption and thermal insulation properties. When bamboo charcoal fiber is loaded on the surface of graphene oxide, graphene oxide can be loaded on the surface and in the pores of bentonite, thereby increasing the specific surface area of ​​bentonite and increasing its mechanical properties, thermal insulation properties and air permeability.

[0022] Konjac glucomannan has good water solubility, film-forming properties, adhesiveness, and thickening properties. When added to the system, konjac glucomannan forms a solution with a certain viscosity. After drying, the konjac glucomannan can coat bentonite, forming a film layer on the surface of the bentonite. This increases the adhesion between the bamboo charcoal fiber and graphene oxide and the bentonite, thereby increasing the overall performance of the bentonite. This contributes to the durability of the bentonite's mechanical properties, thermal insulation properties, and air permeability, resulting in modified bentonite with excellent thermal insulation, air permeability, and mechanical properties.

[0023] Preferably, the mass ratio of bentonite, graphene oxide and bamboo charcoal fiber in step (1) is 1g:0.01-0.03mg:0.1-0.2g.

[0024] By adopting the above technical solution and limiting the mass ratio of bentonite, graphene oxide, and bamboo charcoal fiber, a modified bentonite with superior mechanical properties, good thermal insulation performance, and excellent air permeability is obtained. Bentonite, graphene oxide, and bamboo charcoal fiber have a synergistic effect. The bamboo charcoal fiber is loaded on the surface of the graphene oxide, and the graphene oxide loaded with bamboo charcoal fiber can be loaded on the surface and in the pores of the bentonite, thereby increasing the specific surface area and adsorption capacity of the bentonite. At the same time, it increases the mechanical properties, thermal insulation performance, and air permeability of the bentonite, resulting in a modified bentonite with superior comprehensive performance. In subsequent applications in the preparation of thermal insulation layers, it can improve the mechanical properties, thermal insulation performance, and air permeability of the thermal insulation layer.

[0025] Preferably, the mass ratio of bentonite to konjac glucomannan in step (1) is 1:0.2-0.5.

[0026] By adopting the above technical solution and limiting the mass ratio of bentonite and konjac glucomannan, modified bentonite with superior mechanical properties, better thermal insulation performance, and better air permeability is obtained. Bentonite and konjac glucomannan have a synergistic effect. Konjac glucomannan can coat bentonite, and then coat graphene oxide and bamboo charcoal fiber, thereby increasing the adhesion between bamboo charcoal fiber and graphene oxide and bentonite. This further enhances the durability of the mechanical properties, thermal insulation performance, and air permeability of bentonite. When subsequently applied to the thermal insulation layer, it increases the corresponding comprehensive performance of thermal insulation.

[0027] Preferably, the thickness of the base layer is 2-5 μm, the thickness of the heat insulation layer is 6-10 μm, and the thickness of the outer layer is 8-12 μm.

[0028] By adopting the above technical solution and setting the thickness of the base layer, insulation layer and outer layer, the prepared insulation layer has good comprehensive performance, is lightweight, convenient for subsequent use, has good mechanical properties and thermal insulation, and has excellent comprehensive performance.

[0029] Preferably, the base layer, the insulation layer, and the outer layer are connected by polyethylene adhesive.

[0030] By adopting the above technical solution, polyethylene adhesive has good adhesion, can bond quickly, facilitates construction, and makes the connection between the base layer, the heat insulation layer and the outer layer tight, thereby increasing the overall comprehensive performance of the waterproof and breathable membrane.

[0031] Preferably, the base layer is a TPU layer and the outer layer is a polytetrafluoroethylene layer.

[0032] By adopting the above technical solution, the TPU layer has good tensile properties, abrasion resistance and tear resistance, as well as good elasticity and resilience. As a base layer, it has excellent comprehensive performance. The polytetrafluoroethylene layer has excellent high and low temperature resistance and corrosion resistance. The TPU layer and the polytetrafluoroethylene layer work together to increase the comprehensive performance of the waterproof and breathable membrane, including mechanical properties and chemical corrosion resistance.

[0033] Preferably, the coupling agent is one or more of coupling agent KH560, coupling agent KH550 and coupling agent KH570.

[0034] By adopting the above technical solution, the coupling agent can bind the components in the raw materials together and "couple" them together by chemical bonds, thus acting as a bridge and enabling the composition system to achieve good adhesion, which greatly improves the corrosion resistance, friction resistance and impact resistance of the heat insulation layer.

[0035] Preferably, the dispersant is one or more of 1,6-hexanediol diacrylate, polyethylene wax, and ethylene bis-stearamide.

[0036] By adopting the above technical solution, the dispersant reduces the viscosity of the system, which helps to disperse the raw material components in the system evenly. Combined with the coupling agent, it increases the stability of each component in the system, maximizes the corresponding performance of the components in the system, and thus improves the overall performance of the system.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. The polyurethane acrylate in this application has excellent wear resistance, flexibility, and high elongation at break. It also has good high and low temperature resistance and good adhesion. As a heat insulation layer, it has excellent comprehensive performance. The non-flammability and low density of alumina and silver oxide give it high temperature resistance, thermal shock resistance, and high mechanical strength. At the same time, it can increase the viscosity of the heat insulation layer system, so that the heat insulation layer has good heat insulation and mechanical strength, thereby ensuring the heat insulation performance and mechanical properties of the waterproof and breathable membrane.

[0039] 2. The modified bentonite in this application has a large specific surface area and good adsorption properties, enabling it to adsorb alumina, silver oxide, and nano-titanium dioxide. Moreover, the modified bentonite itself has good thermal insulation and moisture absorption and regulation properties, thereby increasing the thermal insulation performance of the insulation layer system. It can also increase the oxidation resistance, UV radiation resistance, and stability of the insulation layer. Nano-titanium dioxide has antibacterial, deodorizing, thermal insulation, and antifouling properties. The nano-titanium dioxide is loaded on the surface and in the pores of the modified bentonite, thereby increasing the specific surface area of ​​the modified bentonite and further improving the thermal insulation performance of the insulation layer.

[0040] 3. The modified bentonite in this application has a porous and ordered structure. Alumina, silver oxide, and nano-titanium dioxide are uniformly loaded on the surface or within the pore structure of the modified bentonite. The dispersant helps to uniformly disperse alumina, silver oxide, and nano-titanium dioxide, and also helps to uniformly load each component on the surface of the modified bentonite. The modified bentonite has good adsorption, thermal insulation, antibacterial, and thickening properties, while alumina, silver oxide, and nano-titanium dioxide all have good thermal insulation properties. The modified bentonite loaded with alumina, silver oxide, and nano-titanium dioxide further increases the thermal insulation performance of the modified bentonite. Detailed Implementation

[0041] The present application will be further described in detail below with reference to the embodiments.

[0042] The raw materials used in the examples and comparative examples are all commercially available; the coupling agent is coupling agent KH560; and the dispersant is 1,6-hexanediol diacrylate.

[0043] Preparation example of modified bentonite

[0044] Preparation Example 1-1

[0045] The preparation method of modified bentonite includes the following steps:

[0046] (1) 1.5 kg of bentonite was crushed and then soaked in 2.5 L of potassium hydroxide solution for 3 h. After washing with water, the treated bentonite was dispersed in 3 L of deionized water. Sodium carbonate and sodium cellulose were added in a mass ratio of 1:2. The mixture was stirred at 220 °C for 4 h to obtain sodium-based bentonite. Sodium carbonate was 0.2 kg.

[0047] (2) Add graphene oxide and bamboo charcoal fiber to the sodium-based bentonite obtained in step (1), and stir at 80°C for 11 hours to obtain a mixture;

[0048] (3) Add konjac glucomannan to the mixture obtained in step (2), stir at 55°C for 13 min at a stirring rate of 1700 r / min, dry at 85°C for 6 h, and cool to room temperature to obtain modified bentonite.

[0049] In step (1), the mass ratio of bentonite, graphene oxide and bamboo charcoal fiber is 1g:0.01mg:0.1g.

[0050] The mass ratio of bentonite to konjac glucomannan in step (1) is 1:0.5.

[0051] Preparation Examples 1-2

[0052] The difference from Preparation Example 1-1 is that in step (1), potassium hydroxide solution is not added.

[0053] Preparation Examples 1-3

[0054] The difference from Preparation Example 1-1 is that sodium carbonate and sodium cellulose are not added in step (1).

[0055] Preparation Examples 1-4

[0056] The difference from preparation example 1-1 is that graphene oxide is not added in step (2).

[0057] Preparation Examples 1-5

[0058] The difference from preparation example 1-1 is that bamboo charcoal fiber is not added in step (2).

[0059] Preparation Examples 1-6

[0060] The difference from Preparation Example 1-1 is that konjac glucomannan is not added in step (3).

[0061] Preparation Examples 1-7

[0062] The difference from Preparation Example 1-1 is that the mass ratio of bentonite, graphene oxide and bamboo charcoal fiber in step (1) is 1g:0.03mg:0.2g.

[0063] Preparation Examples 1-8

[0064] The difference from Preparation Example 1-1 is that the mass ratio of bentonite, graphene oxide and bamboo charcoal fiber in step (1) is 1g:0.06mg:0.05g.

[0065] Preparation Examples 1-9

[0066] The difference from Preparation Example 1-1 is that the mass ratio of bentonite to konjac glucomannan in step (1) is 1:0.2.

[0067] Preparation Examples 1-10

[0068] The difference from Preparation Example 1-1 is that the mass ratio of bentonite to konjac glucomannan in step (1) is 1:0.8.

[0069] Example

[0070] Example 1

[0071] A waterproof and breathable membrane with heat insulation function includes a base layer, a heat insulation layer and an outer layer arranged sequentially.

[0072] The insulation layer comprises the following raw materials in parts by weight: 110 kg of polyurethane acrylate, 28 kg of alumina, 20 kg of silver oxide, 40 kg of modified bentonite, 17 kg of nano titanium dioxide, 6 kg of coupling agent, and 7 kg of dispersant.

[0073] The method for preparing the above-mentioned heat insulation layer includes the following steps:

[0074] (1) The modified bentonite was dispersed in anhydrous ethanol, and then alumina, silver oxide, nano titanium dioxide and dispersant were added. The mixture was stirred for 2 hours in an inert gas environment at 90°C and then dried to obtain a mixture.

[0075] (2) The mixture obtained in step (1) is mixed with polyurethane acrylate and coupling agent and stirred for 5 hours, then heated to 270°C, extruded, cooled and sliced ​​to obtain heat insulation masterbatch;

[0076] (3) Press the heat insulation masterbatch obtained in step (3) into a film, cool it, eliminate static electricity, roll it up and cut it to obtain the heat insulation layer.

[0077] The thickness of the base layer is 4μm, the thickness of the insulation layer is 8μm, and the thickness of the outer layer is 10μm.

[0078] The base layer, insulation layer, and outer layer are connected by polyethylene adhesive.

[0079] The base layer is a TPU layer, and the outer layer is a polytetrafluoroethylene layer.

[0080] The modified bentonite was prepared using Preparation Example 1-1.

[0081] Example 2

[0082] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-2.

[0083] Example 3

[0084] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-3.

[0085] Example 4

[0086] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-4.

[0087] Example 5

[0088] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-5.

[0089] Example 6

[0090] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-6.

[0091] Example 7

[0092] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-7.

[0093] Example 8

[0094] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-8.

[0095] Example 9

[0096] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-9.

[0097] Example 10

[0098] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that the modified bentonite is prepared using Preparation Examples 1-10.

[0099] Example 11

[0100] A waterproof and breathable membrane with heat insulation function differs from Example 1 in that, in the preparation method of the heat insulation layer, polyurethane acrylate, alumina, silver oxide, modified bentonite, nano titanium dioxide, coupling agent and dispersant are mixed, stirred evenly, heated to 270°C, extruded, cooled and sliced ​​to obtain heat insulation masterbatch; the obtained heat insulation masterbatch is pressed into a film, cooled, static electricity eliminated, wound and cut to obtain the heat insulation layer.

[0101] Example 12

[0102] A waterproof and breathable membrane with heat insulation function, which differs from Example 1 in that the heat insulation layer includes the following raw materials in parts by weight: 100 kg of polyurethane acrylate, 25 kg of alumina, 15 kg of silver oxide, 30 kg of modified bentonite, 15 kg of nano titanium dioxide, 5 kg of coupling agent and 5 kg of dispersant.

[0103] Example 13

[0104] A waterproof and breathable membrane with heat insulation function, which differs from Example 1 in that the heat insulation layer includes the following raw materials in parts by weight: 120 kg of polyurethane acrylate, 30 kg of alumina, 25 kg of silver oxide, 50 kg of modified bentonite, 18 kg of nano titanium dioxide, 8 kg of coupling agent and 8 kg of dispersant.

[0105] Comparative Example

[0106] Comparative Example 1

[0107] A waterproof and breathable membrane with heat insulation function, which differs from Example 1 in that the heat insulation layer includes the following raw materials in parts by weight: 80 kg of polyurethane acrylate, 20 kg of alumina, 10 kg of silver oxide, 25 kg of modified bentonite, 10 kg of nano titanium dioxide, 3 kg of coupling agent and 2 kg of dispersant.

[0108] Comparative Example 2

[0109] A waterproof and breathable membrane with heat insulation function, which differs from Example 1 in that the heat insulation layer includes the following raw materials in parts by weight: 130 kg of polyurethane acrylate, 35 kg of alumina, 30 kg of silver oxide, 55 kg of modified bentonite, 25 kg of nano titanium dioxide, 10 kg of coupling agent and 10 kg of dispersant.

[0110] Comparative Example 3

[0111] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that it does not contain modified bentonite.

[0112] Comparative Example 4

[0113] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that it does not contain nano titanium dioxide.

[0114] Comparative Example 5

[0115] A waterproof and breathable membrane with heat insulation function is different from Example 1 in that an equal amount of bentonite is used instead of modified bentonite.

[0116] The performance testing experiments were conducted on the waterproof and breathable membranes with heat insulation function prepared in Examples 1-13 and Comparative Examples 1-5, and the mechanical properties and heat insulation properties were tested.

[0117] Tensile strength, elongation at break, and tear strength were tested according to ASTM D 882-2010 at a tensile rate of 45 mm / min. Right-angle tear tests of the film were conducted in the transverse and longitudinal directions according to QB / T1130-1991 at a test speed of 180 mm / min. Four parallel samples were tested in each group, and the average value was taken. The results are shown in Table 1.

[0118] Table 1 Test data for the examples and comparative examples

[0119]

[0120]

[0121] As can be seen from Table 1, the waterproof and breathable membranes with heat insulation function prepared in Examples 1, 7, 9 and 12-13 of this application have good mechanical properties and heat insulation performance. The tensile strength reaches 56.5 MPa, the elongation at break reaches 32.3%, and the tear strength reaches 120.1 kN / m. This indicates that the waterproof and breathable membranes with heat insulation function prepared in this application have superior mechanical properties. While ensuring the heat insulation performance of the membrane, they also have good tensile strength, elongation at break and tear strength, which is conducive to the widespread application of breathable membranes.

[0122] In Example 2, the modified bentonite was prepared without the addition of potassium hydroxide solution. As shown in Table 1, compared with Example 1, the mechanical properties were significantly reduced, with a tensile strength of 50.1 MPa, an elongation at break of 25.0%, and a tear strength of 110.3 kN / m. This indicates that the potassium hydroxide solution eroded the bentonite to a certain extent, increasing the pore size of the bentonite and thus increasing the specific surface area of ​​the bentonite. This helps to improve the loading of subsequent components and thus improves the mechanical properties of the bentonite.

[0123] In Example 3, the modified bentonite was prepared without the addition of sodium carbonate and sodium cellulose. As shown in Table 1, compared with Example 1, the mechanical properties were significantly reduced, with a tensile strength of 51.2 MPa, an elongation at break of 25.9%, and a tear strength of 112.3 kN / m. This indicates that the addition of sodium carbonate and sodium cellulose resulted in the preparation of sodium-based bentonite. Sodium-based bentonite has good viscosity, air permeability, and thermal stability, and can be used as a filler in the insulation layer to increase the air permeability and thermal insulation performance of the insulation layer.

[0124] In Example 4, the modified bentonite was prepared without the addition of graphene oxide. As shown in Table 1, compared with Example 1, the mechanical properties were significantly reduced, with a tensile strength of 45.2 MPa, an elongation at break of 20.3%, and a tear strength of 105.2 kN / m. This indicates that graphene oxide has good mechanical properties, thermal insulation properties, air permeability, and chemical stability, and can be loaded on the surface and inside the pores of bentonite, thereby improving the mechanical properties of bentonite.

[0125] In Example 5, the modified bentonite was prepared without bamboo charcoal fiber. As shown in Table 1, compared with Example 1, the mechanical properties were significantly reduced, with a tensile strength of 46.1 MPa, an elongation at break of 21.1%, and a tear strength of 106.2 kN / m. This indicates that bamboo charcoal fiber has good mechanical properties and can be loaded on the surface and in the pores of bentonite, thereby increasing the specific surface area of ​​bentonite and improving its mechanical properties, thermal insulation properties, and air permeability.

[0126] In Example 6, the modified bentonite was prepared without the addition of konjac glucomannan. As shown in Table 1, compared with Example 1, the mechanical properties were significantly reduced, with a tensile strength of 48.7 MPa, an elongation at break of 23.6%, and a tear strength of 109.5 kN / m. This indicates that the konjac glucomannan solution has a certain viscosity and can coat the bentonite, increasing the adhesion between the bamboo charcoal fiber and graphene oxide and the bentonite, thereby increasing the corresponding properties of the bentonite.

[0127] Example 8 changed the mass ratio of bentonite, graphene oxide and bamboo charcoal fiber in step (1). As can be seen from Table 1, the mechanical properties decreased significantly compared with Example 1, but were better than the test results of Examples 4-5. This indicates that bentonite, graphene oxide and bamboo charcoal fiber have a good synergistic effect, and the three have better mechanical properties within a certain proportion range.

[0128] In Example 10, the mass ratio of bentonite and konjac glucomannan in step (1) was changed. As shown in Table 1, the mechanical properties decreased significantly compared to Example 1, but were better than those in Example 6. This indicates that bentonite and konjac glucomannan have a good synergistic effect and exhibit better mechanical properties within a certain ratio range.

[0129] In the preparation method of the insulation layer in Example 11, the order of adding raw materials was changed. As shown in Table 1, compared with Example 1, the mechanical properties decreased significantly. The tensile strength was 51.4 MPa, the elongation at break was 26.3%, and the tear strength was 115.2 kN / m, indicating that the insulation layer prepared by the method of this application has better mechanical properties.

[0130] Comparative Examples 1-2 varied the amount of raw materials used in the insulation layer. As shown in Table 1, compared with Example 1, the tensile strength, elongation at break, and tear strength all decreased significantly. The tensile strength was approximately 42.3 MPa, the elongation at break was approximately 17.3%, and the tear strength was approximately 101.3 kN / m. This indicates that the insulation layer has good mechanical and thermal insulation properties when the raw material components are mixed in a certain proportion. The change in the amount of each raw material affects the corresponding performance of the insulation layer.

[0131] Comparative Example 3, without the addition of modified bentonite, shows, as seen in Table 1, a significant decrease in mechanical properties compared to Example 1. The tensile strength is 35.1 MPa, the elongation at break is 10.3%, and the tear strength is 94.1 kN / m. This indicates that the modified bentonite has good thermal insulation and adsorption properties, and can adsorb alumina, silver oxide, and nano-titanium dioxide, thereby increasing the mechanical properties and other corresponding properties of the modified bentonite.

[0132] Comparative Example 4, without the addition of nano-titanium dioxide, shows, as per Table 1, a significant decrease in mechanical properties compared to Example 1. The tensile strength is 38.9 MPa, the elongation at break is 15.9%, and the tear strength is 96.7 kN / m. This indicates that nano-titanium dioxide possesses antibacterial, deodorizing, and thermal insulation properties. The nano-titanium dioxide is loaded onto the surface and within the pores of the modified bentonite, thereby increasing the mechanical properties of the modified bentonite and further improving the thermal insulation performance of the insulation layer.

[0133] Comparative Example 5 uses an equal amount of bentonite instead of modified bentonite. As shown in Table 1, compared with Example 1 and Comparative Example 3, the mechanical properties are significantly worse than those of Example 1, but better than those of Comparative Example 4. This indicates that the modified bentonite prepared in this application has better mechanical properties, which can further improve the corresponding performance of the waterproof and breathable membrane.

[0134] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A waterproof and breathable membrane with heat insulation function, characterized in that, It includes a base layer, an insulation layer, and an outer layer arranged in sequence; The heat insulation layer comprises the following raw materials in parts by weight: 100-120 parts of polyurethane acrylate, 25-30 parts of alumina, 15-25 parts of silver oxide, 30-50 parts of modified bentonite, 15-18 parts of nano titanium dioxide, 5-8 parts of coupling agent and 5-8 parts of dispersant. The method for preparing the modified bentonite includes the following steps: (1) Crush the bentonite, then soak it in potassium hydroxide solution for 1-3 hours, then wash it with water, disperse the treated bentonite in deionized water, and then add sodium carbonate and sodium cellulose in a mass ratio of 1:1-3. Stir at 200-220℃ for 3-5 hours to obtain sodium-based bentonite. (2) Add graphene oxide and bamboo charcoal fiber to the sodium-based bentonite obtained in step (1), and stir at 80-85℃ for 10-12 hours to obtain a mixture; (3) Add konjac glucomannan to the mixture obtained in step (2), stir at 50-60℃ for 10-15 min at a stirring rate of 1500-1800 r / min, dry at 80-90℃ for 5-6 h, and cool to room temperature to obtain modified bentonite. The mass ratio of bentonite, graphene oxide, and bamboo charcoal fiber is 1g:0.01-0.03mg:0.1-0.2g; The mass ratio of bentonite to konjac glucomannan is 1:0.2-0.

5.

2. The waterproof and breathable membrane with heat insulation function according to claim 1, characterized in that, The method for preparing the heat insulation layer includes the following steps: (1) Disperse the modified bentonite in anhydrous ethanol, then add alumina, silver oxide, nano titanium dioxide and dispersant, stir for 1-2 hours in an inert gas environment at 85-90℃, and dry to obtain a mixture; (2) Mix the mixture obtained in step (1) with polyurethane acrylate and coupling agent and stir for 3-5 hours. Then heat to 260-280℃, extrude, cool and slice to obtain heat insulation masterbatch. (3) Press the heat insulation masterbatch obtained in step (3) into a film, cool it, eliminate static electricity, roll it up and cut it to obtain the heat insulation layer.

3. The waterproof and breathable membrane with heat insulation function according to claim 1, characterized in that, The thickness of the base layer is 2-5 μm, the thickness of the heat insulation layer is 6-10 μm, and the thickness of the outer layer is 8-12 μm.

4. The waterproof and breathable membrane with heat insulation function according to claim 1, characterized in that, The base layer is a TPU layer, and the outer layer is a polytetrafluoroethylene layer.

5. A waterproof and breathable membrane with heat insulation function according to claim 1, characterized in that, The coupling agent is one or more of coupling agent KH560, coupling agent KH550 and coupling agent KH570.

6. The waterproof and breathable membrane with heat insulation function according to claim 1, characterized in that, The dispersant is one or more of 1,6-hexanediol diacrylate, polyethylene wax, and ethylene bis-stearamide.

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