Water-based paint composition, water-based paint, and preparation method and application of water-based paint

Abstract

The invention relates to the technical field of aerogel felt coatings, and discloses a water-based coating composition, a water-based coating and a preparation method and application of the water-based coating. The water-based coating composition comprises water-based resin, siloxane, nanoparticles, a silane coupling agent and water, and the water-based resin is selected from one or more of water-based polyurethane resin, water-based phenolic resin, water-based epoxy resin and water-based urea resin. The main component in the water-based paint composition is water-based resin, the water-based paint composition is safe, environmentally friendly and good in film-forming property, and a compact coating can be formed on the surface of the aerogel felt, so that falling and dusting of silicon dioxide aerogel in the surface processing, transporting and bending processes of the aerogel felt are effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of aerogel felt coating technology, specifically to a water-based coating composition and water-based coating, its preparation method, and its application. Background Technology

[0002] Petrochemical companies typically cover high-temperature pipelines with thick insulation materials. Insulating these pipelines effectively reduces energy consumption and carbon emissions. Traditional materials used for pipeline insulation in petrochemical plants include calcium silicate, composite silicates, rock wool, and polyurethane. However, after long-term operation, pipelines using conventional insulation materials such as calcium silicate, composite silicates, rock wool, and slag wool experience increased heat loss, leading to higher energy consumption. Furthermore, the high temperature on the pipeline's outer surface increases the risk of burns. Additionally, materials like rock wool and aluminum silicate are prone to absorbing water, causing insulation failure, while organic insulation materials like polyurethane have poor flame retardancy, affecting the normal operation of the project.

[0003] Aerogel is a solid material with a nanoporous network structure filled with a gaseous dispersion medium. Compared to traditional insulation materials, aerogel offers superior thermal insulation, longer service life, and excellent waterproofing and flame retardancy, making it the most efficient insulation material currently available and aligning with the major trend of energy conservation and emission reduction. However, the inorganic nanostructure of silica aerogel also makes it brittle, with poor bending and abrasion resistance, hindering its industrial application. While aerogel felts prepared using composite fiber materials show significantly improved strength, the addition of fibers also makes the silica aerogel on the surface of the felt more prone to detachment. This not only affects the long-term insulation performance but also generates dust pollution during construction, which is environmentally unfriendly and detrimental to the health of installation workers. Therefore, improving the dust shedding situation of aerogel materials is extremely important.

[0004] To address this issue, CN114933466A discloses a lightweight thermal insulation layer for special pipelines. This layer reduces dust shedding from the aerogel felt surface by coating the aerogel felt surface with flame-retardant adhesive and fiberglass cloth. While this method effectively reduces dust shedding during application, it involves complex processes and results in thicker, less flexible, and poorly bendable products, making it unsuitable for thermal insulation materials requiring flexibility.

[0005] Therefore, in response to the problems of easy powder shedding in the existing technology, the present invention has developed an aqueous coating composition for the surface of aerogel felt, which not only solves the powder shedding problem, but also does not have a significant impact on the basic properties and use of the material. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem of powder shedding in existing aerogel felts, and to provide a water-based coating composition, a water-based coating, a method for preparing the same, and its application. The main component of the water-based coating composition is a water-based resin, which is safe and environmentally friendly, has good film-forming properties, and can form a dense coating on the surface of the aerogel felt, thereby effectively preventing the silica aerogel from falling off and shedding powder during surface processing, transportation, and bending of the aerogel felt.

[0007] To achieve the above objectives, a first aspect of the present invention provides a waterborne coating composition comprising a waterborne resin, a siloxane, nanoparticles, a silane coupling agent, and water, wherein the waterborne resin is selected from one or more of waterborne polyurethane resin, waterborne phenolic resin, waterborne epoxy resin, and waterborne urea-formaldehyde resin.

[0008] A second aspect of the present invention provides a water-based coating prepared from the aforementioned water-based coating composition.

[0009] A third aspect of the present invention provides a method for preparing the aforementioned water-based coating, wherein the preparation method includes:

[0010] (1) Under stirring conditions, the aqueous resin, siloxane and water are first mixed to obtain a mixture;

[0011] (2) After mixing the nanoparticles and silane coupling agent, the mixture is filtered, washed and dried to obtain modified nanoparticles;

[0012] (3) The modified nanoparticles and the mixture are mixed to obtain an aqueous coating.

[0013] A fourth aspect of the present invention provides an application of the aforementioned water-based coating on the surface of an aerogel felt.

[0014] The water-based coating composition provided by the present invention through the above technical solution has the following advantages:

[0015] (1) The main component of the water-based coating composition is water-based resin, which is safe and environmentally friendly and has good film-forming properties. It can form a dense coating on the surface of aerogel felt, thereby effectively preventing the silica aerogel from falling off and powdering during surface processing, transportation and bending of aerogel felt.

[0016] (2) The siloxane in the water-based coating composition can effectively reduce the surface energy of the coating, while the nanoparticles can effectively increase the surface roughness of the coating, thereby playing a synergistic role in improving the hydrophobicity of the coating, which is beneficial for the storage and use of aerogel felt in humid environments.

[0017] (3) Nanoparticles can be better dispersed in water-based resins after pretreatment with silane coupling agents.

[0018] (4) The water-based coating prepared by the water-based coating composition has little effect on the performance of aerogel felt. After being coated on the surface of aerogel felt and dried, the density increases by no more than 10% and the thermal conductivity increases by no more than 20% compared with the untreated aerogel felt. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] As previously stated, the first aspect of the present invention provides a waterborne coating composition comprising a waterborne resin, a siloxane, nanoparticles, a silane coupling agent, and water, wherein the waterborne resin is selected from one or more of waterborne polyurethane resin, waterborne phenolic resin, waterborne epoxy resin, and waterborne urea-formaldehyde resin.

[0021] The inventors of this invention have discovered that using water-based resin can better form a protective film on the surface of aerogel felt, thereby effectively preventing the silica aerogel from falling off and shedding powder during surface processing, transportation, and bending of the aerogel felt; furthermore, using siloxane and modified nanoparticles can effectively improve the roughness of the coating surface, thereby playing a synergistic role in improving the hydrophobicity of the coating, which is beneficial for the storage and use of aerogel felt in humid environments.

[0022] According to the present invention, preferably, the waterborne resin is a waterborne polyurethane resin and / or a waterborne phenolic resin, more preferably, the waterborne resin is a waterborne polyurethane resin.

[0023] According to the present invention, the solid content of the aqueous resin is 40-60 wt%.

[0024] In this invention, the waterborne polyurethane resin is an aliphatic resin, anionic, with a pH of 7-9 and a viscosity greater than 1000 cP (25°C).

[0025] In this invention, the aqueous phenolic resin has a pH of 7-8 and a viscosity greater than 500 cP (25°C).

[0026] In this invention, the waterborne urea-formaldehyde resin has a pH of 7-8 and a viscosity greater than 800 cP (25°C).

[0027] In this invention, the epoxy equivalent of the waterborne epoxy resin is 450-550 g / mol, and the viscosity is 6000-12000 cP (25℃).

[0028] According to the present invention, relative to 100 parts by weight of the aqueous resin, the content of the siloxane is 5-20 parts by weight, the content of the nanoparticles is 0.5-5 parts by weight, the content of the silane coupling agent is 5-50 parts by weight, and the content of water is 150-900 parts by weight; preferably, relative to 100 parts by weight of the aqueous resin, the content of the siloxane is 10-15 parts by weight, the content of the nanoparticles is 1-2 parts by weight, the content of the silane coupling agent is 10-20 parts by weight, and the content of water is 300-500 parts by weight. In this invention, if the content of the water-based resin is too high, the coating viscosity will be too high, making it difficult to achieve uniform spraying or brushing; if the content of the water-based resin is too low, the film-forming properties of the coating will decrease; if the content of the siloxane is too high, it will affect the film-forming properties of the main coating; if the content of the siloxane is too low, the improvement effect on the hydrophobic properties of the coating will be limited; if the content of the nanoparticles is too high, the particles will easily agglomerate; if the content of the nanoparticles is too low, it will be difficult to construct a rough surface structure of the coating.

[0029] According to the present invention, the siloxane is selected from one or more of methyldimethoxysiloxane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and vinyltriethoxysilane; preferably, the siloxane is selected from methyldimethoxysilane and / or vinyltriethoxysilane.

[0030] According to the present invention, the nanoparticles are selected from one or more of nano-silica, nano-calcium carbonate and nano-titanium dioxide; preferably, the nanoparticles are nano-silica.

[0031] According to the present invention, the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane; preferably, the silane coupling agent is γ-glycidoxypropyltrimethoxysilane (i.e., 3-(2,3-epoxypropoxy)propyltrimethoxysilane).

[0032] According to the present invention, the water is preferably deionized water.

[0033] According to the present invention, the waterborne coating composition further includes a defoamer; preferably, the defoamer is selected from one or more of n-octanol, polyvinyl alcohol and organosilicon defoamers; preferably, the content of the defoamer is 0.5-3 parts by weight relative to 100 parts by weight of the waterborne resin, more preferably 1-2 parts by weight.

[0034] According to the present invention, the water-based coating composition comprises safe and environmentally friendly components and has a simple formulation.

[0035] A second aspect of the present invention provides a water-based coating prepared from the aforementioned water-based coating composition.

[0036] A third aspect of the present invention provides a method for preparing the aforementioned water-based coating, wherein the preparation method includes:

[0037] (1) Under stirring conditions, the aqueous resin, siloxane and water are first mixed to obtain a mixture;

[0038] (2) After mixing the nanoparticles and silane coupling agent, the mixture is filtered, washed and dried to obtain modified nanoparticles;

[0039] (3) The modified nanoparticles and the mixture are mixed to obtain an aqueous coating.

[0040] According to the present invention, in step (1), the aqueous resin, siloxane and water are added to a container and stirred to make them evenly mixed; wherein, the conditions for the first mixing include: a stirring speed of 300-1000 rpm and a stirring time of 1-4 h; preferably, the stirring speed is 500-800 rpm and the stirring time is 1-2 h.

[0041] According to the present invention, in step (2), the nanoparticles and the silane coupling agent are mixed and stirred at low speed, followed by filtration, washing, and drying; wherein the conditions for the second mixing include: a stirring rate of 200-800 rpm and a stirring time of 6-12 h; preferably, the stirring rate is 400-600 rpm and the stirring time is 6-10 h. In the present invention, the solvent used for washing is deionized water.

[0042] According to the present invention, in step (2), the drying conditions include: a temperature of 60-100°C and a drying time of 1-4 hours; preferably, the temperature is 60-80°C and the drying time is 1-2 hours.

[0043] According to the present invention, in step (3), preferably, the modified nanoparticles after step (2) are added to the mixture obtained in step (1), and an antifoaming agent is added and the mixture is ultrasonically stirred for 1 hour to obtain an aqueous coating.

[0044] A fourth aspect of the present invention provides an application of the aforementioned water-based coating on the surface of an aerogel felt.

[0045] According to the present invention, the application includes:

[0046] (1) Blow the aerogel felt to remove powder and particles that are easy to fall off the surface;

[0047] (2) The water-based coating is sprayed and / or brushed onto the surface of the aerogel felt treated in step (1);

[0048] (3) The aerogel felt material after step (2) is cured and coated with a water-based coating layer.

[0049] According to the present invention, the aerogel felt is a silica aerogel felt.

[0050] According to the present invention, in step (3), the curing conditions include: a curing temperature of 80-120°C and a curing time of 2-4 hours; preferably, the curing temperature is 80-100°C and the curing time is 2-3 hours. The mild curing conditions, when applied to the surface of the aerogel felt, result in a low vibrational mass loss rate for the aerogel felt.

[0051] According to the present invention, in step (3), the aerogel felt material processed in step (2) is cured at high temperature, and an aqueous coating layer is applied to the surface of the aerogel felt to obtain an aerogel composite material.

[0052] The present invention will be described in detail below through embodiments.

[0053] In the following examples and comparative examples:

[0054] Thermal conductivity at room temperature: Tested according to GB / T 10294-2008;

[0055] Vibration mass loss rate measurement: Tested according to GB / T 34336-2017 method;

[0056] Contact angle: Tested according to GB / T 30447-2013.

[0057] Waterborne polyurethane and other raw materials are commercially available products from McLean Corporation.

[0058] Example 1

[0059] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0060] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:1:10:1.

[0061] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0062] Example 2

[0063] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0064] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:400:10:1:10:1.

[0065] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0066] Example 3

[0067] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0068] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:500:10:1:10:1.

[0069] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0070] Example 4

[0071] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0072] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:150:10:1:10:1.

[0073] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0074] Example 5

[0075] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0076] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:900:10:1:10:1.

[0077] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0078] Example 6

[0079] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0080] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), methyldimethoxysiloxane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: methyldimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:5:1:10:1.

[0081] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0082] Example 7

[0083] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0084] 1. Preparation of the coating: Waterborne polyurethane resin (with a solid content of 40 wt%), vinyltriethoxysilane, and deionized water were added to a container and stirred at 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane were mixed and stirred at 400 rpm for 6 hours. The mixture was then filtered, washed, and dried at 80°C for 2 hours. Finally, the dried nanoparticles were added to the above mixture, and n-octanol was added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating was: waterborne polyurethane resin: deionized water: vinyltriethoxysilane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:1:10:1.

[0085] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0086] Example 8

[0087] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0088] 1. Preparation of the coating: Waterborne phenolic resin (the solid content of this waterborne polyurethane resin is 40 wt%), methyl dimethoxysiloxane, and deionized water are added to a container and stirred at a stirring rate of 500 rpm for 1 hour to ensure uniform mixing. Simultaneously, nano-silica and 3-(2,3-epoxypropoxy)propyltrimethoxysilane are mixed and stirred at a stirring rate of 400 rpm for 6 hours. After filtration, washing, and drying, the mixture is dried at 80°C for 2 hours. Finally, the dried nanoparticles are added to the above mixture, and n-octanol is added and ultrasonically stirred for 1 hour to obtain the coating composition. The mass ratio of the components in the coating is: waterborne polyurethane resin: deionized water: methyl dimethoxysiloxane: nano-silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:1:10:1.

[0089] 2. Preparation of coated aerogel felt: The silica aerogel felt is purged with air to remove easily detachable powder and particles. The above-mentioned water-based coating is uniformly sprayed onto the treated aerogel felt surface, with a coating composition dosage of 300 g / m². 2 The aerogel felt with a coating was obtained by curing at 80°C for 2 hours.

[0090] Example 9

[0091] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0092] The coated aerogel felt was prepared using the same method as in Example 1, except that "waterborne polyurethane resin" was replaced with "waterborne epoxy resin, wherein the solid content of the waterborne epoxy resin is 60 wt%".

[0093] The result is an aerogel felt with a coating.

[0094] Example 10

[0095] This embodiment illustrates the preparation of coated aerogel felt using the water-based coating composition of the present invention.

[0096] The coated aerogel felt was prepared using the same method as in Example 1, except that "waterborne polyurethane resin" was replaced with "waterborne urea-formaldehyde resin, wherein the solid content of the waterborne urea-formaldehyde resin is 60 wt%".

[0097] The result is an aerogel felt with a coating.

[0098] Comparative Example 1

[0099] Untreated aerogel mats, specifically including: simply blowing air through the surface of the aerogel mat to remove easily detachable powder and particles, without coating treatment, thus serving as a control sample.

[0100] Comparative Example 2

[0101] The coated aerogel felt was prepared using the same method as in Example 1, except that the mass ratio of the components in the coating was changed from "waterborne polyurethane: deionized water: methyl dimethoxysiloxane: nano silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:1:10:1" to "waterborne polyurethane resin: deionized water: methyl dimethoxysiloxane: nano silica resin: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:1:1:10:1".

[0102] The result is an aerogel felt with a coating.

[0103] Comparative Example 3

[0104] The coated aerogel felt was prepared using the same method as in Example 1, except that the mass ratio of the components in the coating was changed from "waterborne polyurethane resin: deionized water: methyl dimethoxysiloxane: nano silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:1:10:1" to "waterborne polyurethane resin: deionized water: methyl dimethoxysiloxane: nano silica: 3-(2,3-epoxypropoxy)propyltrimethoxysilane: n-octanol = 100:300:10:10:10:1".

[0105] The result is an aerogel felt with a coating.

[0106] Test Case

[0107] The performance of the aerogel felts prepared in the examples and comparative examples was tested, and the results are shown in Table 1.

[0108] Table 1

[0109]

[0110]

[0111] As can be seen from the results in Table 1, Examples 1-10 of the present invention have significantly better performance in terms of vibration mass loss rate compared with Comparative Example 1 (untreated aerogel felt), while ensuring that the density of the aerogel felt increases by no more than 10% compared with the untreated aerogel felt, and the room temperature thermal conductivity increases by no more than 20% compared with the untreated aerogel felt, while still maintaining a low density and thermal conductivity. Among them, Examples 1-3 have the best performance.

[0112] Comparing the results of Examples 1, 4, and 5, it can be seen that excessively high or low concentrations of water-based resin in the coating do not have an ideal effect on improving the powder-preventing problem of the material.

[0113] Comparing the results of Example 1 and Example 6, it can be seen that a low concentration of siloxane in the coating does not significantly improve the hydrophobicity of the coating.

[0114] Comparing the results of Example 1 and Example 7, it can be seen that methyldimethoxysilane in the coating is more effective than vinyltriethoxysilane in improving the hydrophobicity of the coating.

[0115] Comparing the results of Examples 1 and 8-10, it can be seen that the waterborne polyurethane resin in the coating improves the material properties better than other waterborne resins.

[0116] Comparing the results of Example 1 and Comparative Example 2, it can be seen that if the siloxane content in the coating is too low, it will affect the hydrophobicity of the coating.

[0117] Comparing the results of Example 1 and Comparative Example 3, it can be seen that if the content of nanoparticles in the coating is too high, it is easy for them to agglomerate, thus affecting the hydrophobicity of the coating.

[0118] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A water-based coating composition, characterized in that, The waterborne coating composition comprises a waterborne resin, a siloxane, nanoparticles, a silane coupling agent, and water, wherein the waterborne resin is selected from one or more of waterborne polyurethane resin, waterborne phenolic resin, waterborne epoxy resin, and waterborne urea-formaldehyde resin.

2. The water-based coating composition according to claim 1, wherein, The solid content of the water-based resin is 40-60 wt%.

3. The water-based coating composition according to claim 1 or 2, wherein, Relative to 100 parts by weight of the aqueous resin, the content of the siloxane is 5-20 parts by weight, the content of the nanoparticles is 0.5-5 parts by weight, the content of the silane coupling agent is 5-50 parts by weight, and the content of water is 150-900 parts by weight. Preferably, relative to 100 parts by weight of the aqueous resin, the content of the siloxane is 10-15 parts by weight, the content of the nanoparticles is 1-2 parts by weight, the content of the silane coupling agent is 10-20 parts by weight, and the content of water is 300-500 parts by weight.

4. The water-based coating composition according to any one of claims 1-3, wherein, The siloxane is selected from one or more of methyldimethoxysiloxane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and vinyltriethoxysilane; And / or, the nanoparticles are selected from one or more of nano-silica, nano-calcium carbonate, and nano-titanium dioxide; And / or, the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

5. The waterborne coating composition according to any one of claims 1-4, wherein, The water-based coating composition also includes a defoamer; Preferably, the defoamer is selected from one or more of n-octanol, polyvinyl alcohol, and silicone defoamers; Preferably, the content of the defoamer is 0.5-3 parts by weight relative to 100 parts by weight of the aqueous resin, more preferably 1-2 parts by weight.

6. A water-based coating prepared from the water-based coating composition according to any one of claims 1-5.

7. A method for preparing the water-based coating according to claim 6, characterized in that, The preparation method includes: (1) Under stirring conditions, the aqueous resin, siloxane and water are first mixed to obtain a mixture; (2) After mixing the nanoparticles and silane coupling agent, the mixture is filtered, washed and dried to obtain modified nanoparticles; (3) The modified nanoparticles and the mixture are mixed to obtain an aqueous coating.

8. The preparation method according to claim 7, wherein, In step (1), the conditions for the first mixing include: a stirring rate of 300-1000 rpm and a stirring time of 1-4 h; And / or, in step (2), the conditions for the second mixing include: a stirring rate of 200-800 rpm and a stirring time of 6-12 h; And / or, in step (2), the drying conditions include: a temperature of 60-100°C and a drying time of 1-4 hours.

9. The application of the water-based coating of claim 6 on the surface of an aerogel felt.

10. The application according to claim 9, wherein, The applications include: (1) Blow the aerogel felt to remove powder and particles that are easy to fall off the surface; (2) The water-based coating is sprayed and / or brushed onto the surface of the aerogel felt treated in step (1); (3) The aerogel felt material after step (2) is cured and coated with a water-based coating layer.

11. The application according to claim 10, wherein, The aerogel felt is a silica aerogel felt; And / or, in step (3), the curing conditions include: a curing temperature of 80-120°C and a curing time of 2-4 hours.

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