Waterproof moisture-permeable coating film as well as preparation method and application thereof

Abstract

The invention discloses a waterproof moisture-permeable coating film as well as a preparation method and application thereof, and belongs to the field of film materials. The waterproof moisture-permeable coating film is prepared from the following raw materials in parts by weight: 45-50 parts of polyurethane resin; 33-42 parts of an organic solvent; 1 to 3 parts of aerogel; 0.5-2 parts of a dispersant; the polyurethane resin is prepared from the following raw materials in parts by weight: 40-50 parts of polyethylene glycol; 7.5 to 15 parts of polytetramethylene ether glycol; 30 to 35 parts of diisocyanate; and 8-10 parts of a chain extender. The fabric has the advantages that the waterproof, breathable and perspiration effects are achieved, and meanwhile the good heat insulation and heat preservation effects are achieved.

Description

Technical Field

[0001] The present application relates to the field of membrane materials, and in particular to a waterproof and breathable coating film, a preparation method thereof, and applications thereof. Background Art

[0002] With the rise of outdoor sports, the market demand for clothing such as jackets and life-saving protective clothing has increased significantly. Most of the jackets or life-saving protective clothing currently sold on the market are made of composite fiber materials. Composite fiber materials are mainly a combination of modified bamboo fibers and other chemical fibers. Composite fiber materials rely on surface resin coatings to achieve corresponding functions.

[0003] In outdoor sports, clothing needs to be waterproof to cope with rainy weather and breathable and sweat-wicking to cope with the wearer's sweating process. As outdoor sports become more and more extensive, the requirements for clothing are also increasing. Therefore, clothing is also required to be able to cope with high altitude and low temperature environments. Therefore, the heat insulation effect of the resin coating on the surface of the clothing is particularly important.

[0004] The current coatings are difficult to obtain good thermal insulation effects while achieving waterproof and breathable perspiration-wicking effects, which limits the application of waterproof and breathable coatings. Summary of the invention

[0005] In order to achieve good thermal insulation and heat preservation effects while achieving waterproof and breathable perspiration effects, the present application provides a waterproof and breathable coating film, a preparation method and an application thereof.

[0006] In the first aspect, the present application provides a waterproof and breathable coating film adopting the following technical solution: A waterproof and breathable coating film is prepared by including the following raw materials in parts by weight: 45-50 parts of polyurethane resin; 33-42 parts of organic solvent; 1 to 3 parts of aerogel; Dispersant 0.5-2 parts; The polyurethane resin is prepared by including the following raw materials in parts by weight: 40-50 parts of polyethylene glycol; 7.5-15 parts of polytetramethylene ether glycol; 30-35 parts of diisocyanate; Chain extender 8-10 parts.

[0007] By adopting the above technical solution, aerogel is added to the polyurethane resin. The aerogel has high porosity, low density and large specific surface area, so it has a low thermal conductivity, which can improve the thermal insulation performance of the polyurethane coating. For polyurethane coatings with waterproof and breathable requirements, the addition of aerogel will affect the pore size and distribution of the coating, and then affect the waterproof and breathable properties of the coating. Based on this, the coating of the present application is based on the polyurethane resin prepared from the above-mentioned proportion of raw materials, and polyethylene glycol and polytetramethylene ether glycol are compounded as polyether diols, so that the polyurethane resin itself has high waterproof and breathable properties. In addition, the polyurethane resin obtains good compatibility with the aerogel. While dispersing the aerogel, a good arrangement is formed between the aerogels, which not only extends the heat transfer path and gives full play to the thermal insulation effect of the aerogel, but also reduces the negative impact of the aerogel on the fine pore structure of the coating, ensuring the water pressure resistance and moisture permeability of the coating, thereby achieving waterproof and breathable perspiration effects while obtaining good thermal insulation effects.

[0008] Optionally, the number average molecular weight of the polyethylene glycol is 2000-6000, and the number average molecular weight of the polytetramethylene ether glycol is 1000-3000.

[0009] Optionally, the number average molecular weight of the polyethylene glycol is 4000-5000, and the number average molecular weight of the polytetramethylene ether glycol is 2000-2500.

[0010] By adopting the above technical scheme, the number average molecular weight combination of polyethylene glycol and polytetramethylene ether glycol is optimized, and while ensuring the waterproof and moisture permeability of the coating, the interfacial compatibility with the aerogel is improved, ensuring that the mechanical properties of the coating meet the standards, and being able to give full play to the thermal insulation and heat preservation effect of the aerogel, so that it can be applied to the surface of clothing such as jackets.

[0011] Optionally, the diisocyanate includes one or both of 4'4-diphenylmethane diisocyanate and 2'4-diphenylmethane diisocyanate.

[0012] Optionally, the chain extender includes one or both of 1,4-butanediol and 1,6-hexanediol.

[0013] Optionally, the aerogel is a silicon-based aerogel.

[0014] By adopting the above technical solutions, the silicon aerogel has excellent stability and continuously provides thermal insulation functions.

[0015] Optionally, the aerogel includes one or both of silicon dioxide aerogel and silicon carbide aerogel.

[0016] Optionally, the specific surface area of ​​the aerogel is 600 to 750 m 2 / g, the density of the aerogel is 0.07-0.10g / cm 3 .

[0017] By adopting the above technical solution, aerogel is prepared by sol-gel and drying, so that the aerogel forms a fine porous network structure, has the advantages of high specific surface area and low density, and performs well in thermal insulation, but it also brings the problem of easy spontaneous agglomeration. With the cooperation of the specially prepared polyurethane resin and dispersant in the present application, the dispersion stability of the aerogel in the film-forming system is promoted, and the occurrence of spontaneous agglomeration is reduced after sufficient stirring, so that the coating film obtains good thermal insulation effect while ensuring waterproof and moisture permeability.

[0018] Optionally, the dispersant is a graft copolymer dispersant.

[0019] By adopting the above technical scheme and the chain segment grafting combination of the dispersant, the compatibility of the aerogel and the polyurethane film-forming chain segment is improved, thereby improving the dispersibility of the aerogel, forming a stable thermal insulation network structure, and controlling the size and distribution of the membrane's micropores, thereby improving the thermal insulation performance and waterproof and moisture permeability.

[0020] Preferably, the dispersant is a graft copolymer dispersant with a nonlinear comb-like structure.

[0021] By adopting the above technical solution, the nonlinear comb structure in the dispersant helps to further improve the dispersion uniformity of the aerogel.

[0022] Optionally, the organic solvent includes one or both of N,N-dimethylformamide and ethyl acetate.

[0023] Optionally, the weight portion of N,N-dimethylformamide included in the raw material is 18 to 22 parts, and the weight portion of ethyl acetate is 15 to 20 parts.

[0024] By adopting the above technical solution, the selection of organic solvent will affect the curing process of the coating. Therefore, a specific ratio of N,N-dimethylformamide and ethyl acetate is selected as the organic solvent. While fully dispersing the raw materials, the volatilization rate of the organic solvent can be better controlled, so that the micropore structure during film formation is more in line with the requirements of a waterproof and breathable membrane.

[0025] Optionally, the raw materials further include one or more of a matting agent, an antioxidant and an anti-ultraviolet agent.

[0026] By adopting the above technical scheme, the matting agent can adjust the glossiness of the coating according to the design requirements of the coating; the antioxidant and anti-ultraviolet agent can resist the interference of the external environment to a certain extent to improve the durability of the coating.

[0027] Optionally, the weight portion of the matting agent included in the raw material is 1 to 3 parts, and the matting agent is fumed silica.

[0028] By adopting the above technical solution, fumed silica is prepared by high-temperature sintering or vapor deposition. For example, silicon halide is hydrolyzed at high temperature in a hydrogen-oxygen flame to generate smoky silica with extremely fine particles, which has a denser structure, higher density and good shading effect.

[0029] In the second aspect, the present application provides a method for preparing a waterproof and breathable coating film using the following technical solution: A method for preparing a waterproof and breathable coating film comprises the following steps: The polyethylene glycol and polytetramethylene ether glycol are mixed, inert gas is introduced for protection, heated, diisocyanate is added for prepolymerization, a chain extender is added for further reaction, and the material is discharged to obtain a polyurethane resin; The polyurethane resin, organic solvent, aerogel and dispersant are mixed, stirred and dispersed evenly, and degassed to obtain a polyurethane slurry; The polyurethane slurry is coated on the surface of the release material, dried, and separated to obtain a waterproof and moisture-permeable coating film.

[0030] In the third aspect, the application of a waterproof and breathable coating provided by the present application adopts the following technical solution: An application of a waterproof and breathable coating film, wherein the waterproof and breathable coating film is applied to a surface layer of clothing.

[0031] Optionally, the waterproof and breathable coating film is applied to the surface layer of the clothing by first forming a film on the surface of the release material and then bonding or sewing it to the fabric surface of the clothing.

[0032] Optionally, the waterproof and breathable coating is applied to the surface layer of clothing by dipping the surface of the fabric of the clothing into a film.

[0033] In summary, this application has the following beneficial effects: 1. The present application adds aerogel to the polyurethane resin. The aerogel has high porosity, low density and large specific surface area, so it has a low thermal conductivity, which can improve the thermal insulation performance of the polyurethane coating. For polyurethane coatings with waterproof and breathable requirements, the addition of aerogel will affect the pore size and distribution of the coating, and then affect the waterproof and breathable properties of the coating. Based on this, the coating of the present application is based on the polyurethane resin made from the above-mentioned proportion of raw materials, and polyethylene glycol and polytetramethylene ether glycol are compounded as polyether diols, so that the polyurethane resin itself has high waterproof and breathable properties. In addition, the polyurethane resin has good compatibility with the aerogel. While dispersing the aerogel, the aerogels are well arranged, which not only prolongs the heat transfer path and gives full play to the thermal insulation effect of the aerogel, but also reduces the negative impact of the aerogel on the fine pore structure of the coating, ensuring the water pressure resistance and moisture permeability of the coating, thereby achieving waterproof and breathable perspiration effects while obtaining good thermal insulation effects.

[0034] 2. This application optimizes the number average molecular weight combination of polyethylene glycol and polytetramethylene ether glycol and the size of the aerogel, ensuring the waterproof and moisture permeability of the coating while improving the interfacial compatibility with the aerogel, ensuring that the mechanical properties of the coating meet the standards, and being able to give full play to the thermal insulation and heat preservation effect of the aerogel, so that it can be applied to the surface of clothing such as jackets. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a photograph of the waterproof and breathable coating film prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1 This application is described in further detail.

[0037] Example 1 A method for preparing a waterproof and breathable coating film comprises the following steps: Weigh 4 kg of polyethylene glycol, 1.5 kg of polytetramethylene ether glycol, 3 kg of 4,4'-diphenylmethane diisocyanate, and 0.8 kg of 1,4-butanediol, wherein the number average molecular weight of polyethylene glycol is 2000; the number average molecular weight of polytetramethylene ether glycol is 3000.

[0038] Polyethylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0039] Weigh 4.5 kg of the polyurethane resin prepared above, 0.1 kg of silica aerogel, 0.05 kg of dispersant, 1.8 kg of N,N-dimethylformamide, 1.5 kg of ethyl acetate, 0.1 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent. The specific surface area of ​​the silica aerogel is 600 m 2 / g, density is 0.10g / cm 3 The dispersant is a nonlinear comb-structured graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0040] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0041] The polyurethane slurry is coated on the surface of the release paper by roller coating, dried at 130°C, and separated to obtain a waterproof and breathable coating film with a coating thickness of 0.03 mm. Figure 1 shown.

[0042] Example 2 A method for preparing a waterproof and breathable coating film comprises the following steps: Weigh 5 kg of polyethylene glycol, 0.75 kg of polytetramethylene ether glycol, 3.5 kg of 4,4'-diphenylmethane diisocyanate, and 1 kg of 1,4-butanediol, wherein the number average molecular weight of polyethylene glycol is 6000; the number average molecular weight of polytetramethylene ether glycol is 1000.

[0043] Polyethylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0044] Weigh 5 kg of the polyurethane resin prepared above, 0.3 kg of silica aerogel, 0.2 kg of dispersant, 2.2 kg of N,N-dimethylformamide, 2 kg of ethyl acetate, 0.3 kg of fumed silica, 0.02 kg of antioxidant, and 0.03 kg of anti-ultraviolet agent. The specific surface area of ​​the silica aerogel is 600 m 2 / g, density is 0.10g / cm 3The dispersant is a nonlinear comb-structured graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0045] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0046] The polyurethane slurry was coated on the surface of the release paper by roller coating, dried at 130° C., and separated to obtain a waterproof and moisture-permeable coating film with a coating thickness of 0.03 mm.

[0047] Example 3 A method for preparing a waterproof and breathable coating film comprises the following steps: Weigh 4.5 kg of polyethylene glycol, 1 kg of polytetramethylene ether glycol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, and 0.9 kg of 1,4-butanediol, wherein the number average molecular weight of polyethylene glycol is 3000; the number average molecular weight of polytetramethylene ether glycol is 2500.

[0048] Polyethylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0049] Weigh 4.6 kg of the polyurethane resin prepared above, 0.25 kg of silica aerogel, 0.1 kg of dispersant, 2 kg of N,N-dimethylformamide, 1.8 kg of ethyl acetate, 0.2 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent. The specific surface area of ​​the silica aerogel is 750 m 2 / g, density is 0.07g / cm 3 The dispersant is a nonlinear comb-structured graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0050] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0051] The polyurethane slurry was coated on the surface of the release paper by roller coating, dried at 130° C., and separated to obtain a waterproof and moisture-permeable coating film with a coating thickness of 0.03 mm.

[0052] Example 4 A method for preparing a waterproof and breathable coating film.

[0053] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane resin.

[0054] Specifically, 4.5 kg of polyethylene glycol, 1 kg of polytetramethylene ether glycol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, and 0.9 kg of 1,4-butanediol were weighed, wherein the number average molecular weight of polyethylene glycol was 4000; and the number average molecular weight of polytetramethylene ether glycol was 2000.

[0055] Polyethylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0056] Example 5 A method for preparing a waterproof and breathable coating film.

[0057] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane resin.

[0058] Specifically, 4.5 kg of polyethylene glycol, 1 kg of polytetramethylene ether glycol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, and 0.9 kg of 1,4-butanediol were weighed, wherein the number average molecular weight of polyethylene glycol was 5000; and the number average molecular weight of polytetramethylene ether glycol was 2500.

[0059] Polyethylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0060] Example 6 A method for preparing a waterproof and breathable coating film.

[0061] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane slurry.

[0062] Specifically, 4.6 kg of the polyurethane resin obtained in Example 3, 0.25 kg of silica aerogel, 0.1 kg of dispersant, 2 kg of N,N-dimethylformamide, 1.8 kg of ethyl acetate, 0.2 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent were weighed. The specific surface area of ​​the silica aerogel is 750 m 2 / g, density is 0.07g / cm 3 ; The dispersant is an anionic graft copolymer dispersant, model SPE 108; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the anti-ultraviolet agent is UV531.

[0063] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0064] Example 7 A method for preparing a waterproof and breathable coating film.

[0065] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane slurry.

[0066] Specifically, 4.6 kg of the polyurethane resin obtained in Example 3, 0.25 kg of silica aerogel, 0.1 kg of dispersant, 2 kg of N,N-dimethylformamide, 1.8 kg of ethyl acetate, 0.2 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent were weighed. The specific surface area of ​​the silica aerogel is 850 m 2 / g, density is 0.06g / cm 3 The dispersant is a nonlinear comb-like graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0067] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0068] Example 8 A method for preparing a waterproof and breathable coating film.

[0069] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane slurry.

[0070] Specifically, 4.6 kg of the polyurethane resin obtained in Example 3, 0.25 kg of silica aerogel, 0.1 kg of dispersant, 2 kg of N,N-dimethylformamide, 1.8 kg of ethyl acetate, 0.2 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent were weighed. The specific surface area of ​​the silica aerogel is 500 m 2 / g, density is 0.11g / cm 3 The dispersant is a nonlinear comb-structured graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0071] The polyurethane resin, silica aerogel, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0072] Example 9 A method for preparing a waterproof and breathable coating film.

[0073] The difference between this embodiment and embodiment 3 lies in the difference in polyurethane slurry.

[0074] Specifically, 4.6 kg of the polyurethane resin obtained in Example 3, 0.25 kg of silica aerogel, 0.1 kg of dispersant, 2 kg of butanone, 1.8 kg of ethyl acetate, 0.2 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent were weighed. The specific surface area of ​​the silica aerogel is 750 m 2 / g, density is 0.07g / cm 3 The dispersant is a nonlinear comb-structured graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica is 80 nm; the antioxidant is antioxidant 1010; and the UV inhibitor is UV531.

[0075] The polyurethane resin, silica aerogel, dispersant, butanone, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0076] Comparative Example 1 A method for preparing a waterproof and breathable coating film.

[0077] The difference between this comparative example and Example 3 lies in the difference in polyurethane slurry.

[0078] Specifically, 4.6 kg of the polyurethane resin obtained in Example 3, 0.1 kg of dispersant, 2 kg of N,N-dimethylformamide, 1.8 kg of ethyl acetate, 0.45 kg of fumed silica, 0.01 kg of antioxidant, and 0.02 kg of anti-ultraviolet agent were weighed. Among them, the dispersant was a nonlinear comb-like graft copolymer dispersant, model SPE 107-1; the average particle size of the fumed silica was 80 nm; the antioxidant was antioxidant 1010; and the anti-ultraviolet agent was UV531.

[0079] The polyurethane resin, dispersant, N,N-dimethylformamide, ethyl acetate, fumed silica, antioxidant and anti-ultraviolet agent were mixed, dispersed at a high speed of 1300 rpm with stirring for 30 minutes, and vacuum degassing was performed to obtain a polyurethane slurry.

[0080] Comparative Example 2 A method for preparing a waterproof and breathable coating film.

[0081] The difference between this comparative example and Example 3 lies in the difference in polyurethane resin.

[0082] Specifically, 4.5 kg of polyethylene glycol, 1 kg of polypropylene glycol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, and 0.9 kg of 1,4-butanediol were weighed, wherein the number average molecular weight of polyethylene glycol was 3000, and the number average molecular weight of polypropylene glycol was 3000.

[0083] Polyethylene glycol and polypropylene glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO groups was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0084] Comparative Example 3 A method for preparing a waterproof and breathable coating film.

[0085] The difference between this comparative example and Example 3 lies in the difference in polyurethane resin.

[0086] Specifically, 4.5 kg of polypropylene glycol, 1 kg of polytetramethylene ether glycol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, and 0.9 kg of 1,4-butanediol were weighed, wherein the number average molecular weight of the polypropylene glycol was 3000; and the number average molecular weight of the polytetramethylene ether glycol was 2500.

[0087] Polypropylene glycol and polytetramethylene ether glycol were mixed, nitrogen was introduced for protection, the reaction system was heated to 80°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization reaction was carried out for 2 hours, 1,4-butanediol was added and the reaction was continued for 2 hours, the residual amount of -NCO group was detected, di-n-butylamine was calculated and added to consume the residual 4,4'-diphenylmethane diisocyanate, and the material was discharged to obtain a polyurethane resin.

[0088] Performance Testing: Water pressure resistance test: With reference to JIS L1092 "Water resistance of textiles" hydrostatic pressure test B, the waterproof and breathable coating film was subjected to a water pressure resistance test. The test results are shown in Table 1.

[0089] Water vapor permeability test: Referring to JIS L1099 B1 (potassium acetate-inverted cup method), the water vapor permeability test of the waterproof and breathable coating was carried out. The test results are shown in Table 1.

[0090] Thermal conductivity test: The thermal conductivity of the waterproof and breathable coating was tested using a thermal conductivity tester. The test results are shown in Table 1.

[0091] Table 1 According to the test results of water pressure resistance, moisture permeability and thermal conductivity, it can be seen that the coatings of Examples 1-3 have the advantages of high water pressure resistance, high moisture permeability and low thermal conductivity, meeting the performance requirements of clothing such as jackets in terms of waterproof, moisture permeability, and thermal insulation.

[0092] Comparing Comparative Example 1 with Example 3, it can be seen that when the coating is only filled with fumed silica, the thermal conductivity of the coating is high, greater than 0.12 W / m·K, which does not meet the requirements of thermal insulation materials and is difficult to meet the requirements of thermal insulation of clothing such as jackets, indicating that aerogel has excellent thermal insulation effect in the coating, and the low density of aerogel reduces the impact on the waterproof and moisture permeability of the coating.

[0093] Comparing Comparative Examples 2-3 with Example 3, it can be seen that when the polyether diol is compounded with polyethylene glycol and polytetramethylene ether glycol, the obtained polyurethane resin not only maintains the stability of the fine pores of the coating film, thereby achieving a good balance between water pressure resistance and moisture permeability, but also has the best compatibility with aerogel, promotes the full dispersion of aerogel and forms a stable thermal insulation network structure, greatly reduces the thermal conductivity of the coating film, and improves the thermal insulation performance.

[0094] Comparing Example 3 with Examples 4-5, it can be seen that when polyethylene glycol and polytetramethylene ether glycol with a specific molecular weight are used, the polyurethane segment structure of the coating and the dispersed structure of the aerogel are further optimized, which can further improve the water pressure resistance of the coating and reduce the thermal conductivity of the coating, thereby promoting waterproofing and heat insulation effects.

[0095] Comparing Example 3 with Example 6, it can be seen that the nonlinear comb-like structured graft copolymer dispersant has a better dispersion effect on the aerogel, and promotes the reduction of the thermal conductivity of the coating.

[0096] Comparing Example 3 with Examples 7-8, it can be seen that when the size parameters of the aerogel are maintained within a specific range, the thermal conductivity of the coating can be kept below 0.05 W / m·K, meeting the requirements of high-efficiency thermal insulation materials, and the appropriate size parameters make the aerogel more compatible with the polyurethane chain segments, ensuring that the waterproof and moisture permeability effect of the coating is at a good level.

[0097] Comparing Example 3 with Example 9, it can be seen that the volatility of the organic solvent will affect the formation of the coating film. Therefore, the selection of the organic solvent has a certain influence on the final waterproof, moisture permeability and heat insulation effect of the coating film.

[0098] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A waterproof and breathable coating film, characterized in that: Prepared by including the following raw materials in parts by weight: 45-50 parts of polyurethane resin; 33-42 parts of organic solvent; Aerogel 1-3 parts; Dispersant 0.5~2 parts; The polyurethane resin is prepared by including the following raw materials in parts by weight: 40-50 parts of polyethylene glycol; 7.5-15 parts of polytetramethylene ether glycol; 30-35 parts of diisocyanate; Chain extender 8~10 parts.

2. A waterproof and breathable coating according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol is 2000-6000, and the number average molecular weight of the polytetramethylene ether glycol is 1000-3000.

3. A waterproof and breathable coating according to claim 2, characterized in that: The number average molecular weight of the polyethylene glycol is 4000-5000, and the number average molecular weight of the polytetramethylene ether glycol is 2000-2500.

4. The waterproof and breathable coating according to claim 1, characterized in that: The specific surface area of ​​the aerogel is 600-750 m 2 / g, the density of the aerogel is 0.07~0.10g / cm 3 .

5. The waterproof and breathable coating according to claim 1, characterized in that: The dispersant is a graft copolymer dispersant.

6. The waterproof and breathable coating according to claim 1, characterized in that: The organic solvent includes one or both of N,N-dimethylformamide and ethyl acetate.

7. A waterproof and breathable coating according to any one of claims 1 to 6, characterized in that: The raw materials also include one or more of a matting agent, an antioxidant and an anti-ultraviolet agent.

8. The waterproof and breathable coating according to claim 7, characterized in that: The weight portion of the matting agent included in the raw material is 1 to 3 parts, and the matting agent is fumed silica.

9. A method for preparing a waterproof and breathable coating film according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polyethylene glycol and polytetramethylene ether glycol are mixed, inert gas is introduced for protection, heated, diisocyanate is added for prepolymerization, a chain extender is added for further reaction, and the material is discharged to obtain a polyurethane resin; The polyurethane resin, organic solvent, aerogel and dispersant are mixed, stirred and dispersed evenly, and degassed to obtain a polyurethane slurry; The polyurethane slurry is coated on the surface of the release material, dried, and separated to obtain a waterproof and moisture-permeable coating film.

10. Application of a waterproof and breathable coating film according to any one of claims 1 to 8, characterized in that: The waterproof and breathable coating film is applied to the surface layer of clothing.

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