Aqueous aerogel insulation mass coat and method of making

Abstract

The application relates to the paint technology field, in particular to a water-based aerogel heat-insulating thick intermediate paint and a preparation method thereof.According to mass fractions, the water-based aerogel heat-insulating thick intermediate paint comprises 12-14 parts of modified hollow glass microbeads, 6-8 parts of aerogel particles, 5 parts of elastic acrylic emulsion, 20-25 parts of styrene-acrylic emulsion, 0.5 part of hydrophobic fumed silica, 0-2 parts of a crosslinking agent, 2 parts of an additive, 1-2 parts of a film-forming agent, 0.3 part of a pH regulator and 45-50 parts of deionized water.The particle size of the aerogel particles is 600 mu m; and the preparation method of the modified hollow glass microbeads comprises the following steps: after hollow glass microbeads are cleaned by using acetone or ethanol, the hollow glass microbeads and gamma-aminopropyl triethoxysilane are added into 25% ethanol solution at a mass ratio of 100:1, the mixture is uniformly mixed, a modifier is added, and stirring is carried out at 1500-2000 rpm for 10 min to obtain the modified hollow glass microbeads.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a water-based aerogel thermal insulation thick intermediate coating and its preparation method. Background Technology

[0002] Under my country's current "dual carbon" goal, energy conservation and emission reduction will become the main direction for the future development of the construction industry. Aerogel, also known as "blue smoke," has received widespread attention in the field of building energy conservation in recent years due to its extremely low density, relatively high specific surface area, and excellent thermal insulation performance. It is widely used in coatings, felts, and concrete mortars.

[0003] Aerogel thermal insulation thick intermediate coating is a new type of coating for building and pipeline insulation, prepared using acrylic emulsion as a binder, aerogel material as thermal insulation filler, hollow glass microspheres as coating skeleton, and deionized water as diluent. In traditional preparation processes, aerogel powder with a particle size of 100μm is often used to prepare water-based aerogel thermal insulation thick intermediate coating. However, on the one hand, due to its hydrophobicity and extremely low density, aerogel powder is very easy to float in the air and cannot be directly added to the water-based aerogel thermal insulation thick intermediate coating. It must be prepared into a water slurry with a certain solid content through a complex process before use, which not only prolongs the production cycle but also wastes energy. On the other hand, due to the large specific surface area of ​​hollow glass microspheres, the resulting coating has poor stability and workability and is prone to cracking. Summary of the Invention

[0004] This application provides a water-based aerogel thermal insulation thick intermediate coating and its preparation method, in order to solve the problem in related technologies that, while using hollow glass microspheres to enhance thermal insulation performance, the stability and workability of the coating cannot be guaranteed.

[0005] In a first aspect, a water-based aerogel insulating thick intermediate coating is provided, comprising, by weight parts:

[0006] 12-14 parts modified hollow glass microspheres, 6-8 parts aerogel particles, 5 parts elastic acrylic emulsion, 20-25 parts styrene-acrylic emulsion, 0.5 parts hydrophobic fumed silica, 0-2 parts crosslinking agent, 2 parts additives, 1-2 parts film-forming agent, 0.3 parts pH adjuster, and 45-50 parts deionized water.

[0007] The aerogel particles have a particle size of 600 μm;

[0008] The method for preparing the modified hollow glass microspheres includes:

[0009] After the hollow glass microspheres are cleaned with acetone or ethanol, the hollow glass microspheres and γ-aminopropyl triethoxysilane are added into a 25% ethanol solution at a mass ratio of 100:1, and then a modifier is added after being uniformly mixed, and stirring is carried out at 1500-2000 rpm for 10 min to obtain modified hollow glass microspheres.

[0010] Preferably, the modifier comprises a water-based polyurethane resin, an aminoethyl phosphinic acid, a tannic acid, and deionized water, and the mass ratio of the water-based polyurethane resin, the aminoethyl phosphinic acid, the tannic acid, and the deionized water is (5-8):(1-2):(0-1):100.

[0011] Preferably, the elastic acrylic emulsion comprises deionized water, a composite monomer, an initiator, an emulsifier, NaHCO3, and ammonia water at a mass ratio of 50:47.5:1.8:1.2:1:1.

[0012] The emulsifier is one or more of sodium dodecyl benzene sulfonate SDBS, dodecyl phenol polyoxyethylene ether OP-10, and fatty alcohol polyoxyethylene ether AEO-9.

[0013] Preferably, the composite monomer comprises a hard monomer, a soft monomer, and a functional monomer at a mass ratio of 8:10:1.

[0014] The hard monomer is one or more of styrene St, methyl methacrylate MMA, and acrylonitrile AN, the soft monomer is one or more of isooctyl acrylate 2-EHA, butyl acrylate BA, and ethyl acrylate EA, and the functional monomer is one or more of glycidyl methacrylate GMA, isobornyl acrylate IBOA, and hydroxypropyl acrylate HPA.

[0015] Preferably, the crosslinking agent is microcrystalline cellulose, and the microcrystalline cellulose has a diameter of 10-20 nm.

[0016] Preferably, the auxiliary agent comprises a bactericide, a macromolecular dispersant, a wetting agent, and an antifoaming agent at a mass ratio of 2:5:5:5.

[0017] Preferably, the film-forming agent comprises one or more of DPNB, DPM, and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

[0018] In a second aspect, a preparation method of an aqueous aerogel thermal insulation heavy coating is provided, which is used for preparing the aqueous aerogel thermal insulation heavy coating as described in any one of the above aspects, and the preparation method comprises the following steps:

[0019] S1, deionized water, an auxiliary agent, and hydrophobic fumed silica are added into a stirring tank, and stirring and mixing are carried out to uniformly disperse;

[0020] S2, stirring after mixing the elastic acrylic emulsion, styrene-acrylic emulsion, film forming agent and pH regulator, and adding the mixture obtained in S1 during stirring;

[0021] S3, adding a crosslinking agent, aerogel particles and modified hollow glass microspheres to the product obtained in S2, stirring uniformly to obtain the water-based aerogel thermal insulation thick intermediate coating.

[0022] Preferably, the preparation method of the elastic acrylic emulsion comprises the following steps:

[0023] a, adding the emulsifier to a three-necked flask after mixing with deionized water, then adding the composite monomer, and stirring at high speed for 30 min to obtain a pre-emulsion;

[0024] b, adding 1 / 5 of the pre-emulsion to a four-necked flask, then adding NaHCO3 and 1 / 3 of the initiator in it, purging nitrogen for half an hour to remove air, then increasing the temperature to 80℃, adjusting the stirring speed to 400r / min, and reacting until blue light appears under the condition of condensate water;

[0025] c, adding the remaining pre-emulsion to the product obtained in step b dropwise, and dropwise for 3h, adding 1 / 3 of the initiator 6 times during the reaction, after dropwise addition, the temperature is reduced to 45℃ after 3h of incubation, then the remaining initiator is added, and the reaction is terminated after 20min of reaction, and the pH value of the emulsion is adjusted to 8-9 by adding ammonia water, and the obtained milky white flood light liquid is the target emulsion.

[0026] The technical scheme provided by the application brings the beneficial effects including:

[0027] (1) The water-based aerogel thermal insulation thick intermediate coating and the preparation method thereof provided by the application use aerogel particles with a particle size of 600μm, aerogel powders with a particle size of less than 100μm need to be made into pre-slurry with a certain solid content by a complex process before being added to the water-based aerogel thermal insulation thick intermediate coating, and the aerogel particles with a particle size of 600μm can be directly added to the water-based aerogel thermal insulation thick intermediate coating, so that the production process of the water-based aerogel thermal insulation thick intermediate coating can be simplified, and industrial production can be easily realized.

[0028] (2) The aerogel particles with a particle size of 600μm have a larger particle size than the aerogel powders with a particle size of less than 100μm, under the same addition amount, the aerogel particles with a particle size of 600μm can bring a more loose coating to the water-based aerogel thermal insulation thick intermediate coating, and can reduce the coating weight under the same thickness and the thermal conductivity of the water-based aerogel thermal insulation thick intermediate coating, while having little effect on the bonding strength.

[0029] (3) By self-made elastic acrylic emulsion and styrene-acrylic emulsion, the side effect of large particle size aerogel particles on the flexibility of the coating can be solved, so that the coating can meet the standard in flexibility while meeting the standard in bonding strength;

[0030] (4) Fumed silica is used as a sedimentation inhibitor in the intermediate coating. Fumed silica has small particle size and high surface energy, which can act as a dispersing aid. Adding fumed silica to the aerogel dispersion slurry makes the hydrophobic aerogel particles easier to disperse in water. Due to the presence of a large number of silanol bonds on the surface of fumed silica, it can form a "net" structure by itself or with the substrate, which can hold the light thermal filler such as aerogel particles and hollow glass microspheres, preventing them from floating. The intermediate coating made of fumed silica is less likely to separate during storage, and it can restore the working state without long stirring. Moreover, due to the small nano structure and high surface activity of fumed silica, the bonding strength between thick intermediate coating and substrate can be improved;

[0031] (5) Hollow glass microspheres are modified to enhance the surface toughness and form cross-linking with the porous structure of aerogel, which enhances the interface bonding between the two phases, inhibits the crack propagation of the coating, and effectively ensures the strength of the coating. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 The flow chart of the preparation method of the water-based aerogel thermal insulation thick intermediate coating provided by the present application is shown in the figure.

[0034] Figure 2 The SEM images of the water-based aerogel thermal insulation thick intermediate coating prepared by Example 1 and Comparative Example 1 of the present application under different magnifications are shown in the figure.

[0035] Figure 3 The simultaneous thermal analysis diagram of the water-based aerogel thermal insulation thick intermediate coating prepared by Example 1 of the present application is shown in the figure. DETAILED DESCRIPTION

[0036] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0037] Referring to Figures 1 to 3 As shown in the drawings, the present application provides a water-based aerogel thermal insulation heavy-duty mid-coat paint, which comprises, in terms of mass parts, modified hollow glass microbeads 12-14 parts, aerogel particles 6-8 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion 20-25 parts, hydrophobic fumed silica 0.5 part, crosslinking agent 0-2 parts, auxiliary agent 2 parts, film-forming agent 1-2 parts, pH regulator 0.3 part, and deionized water 45-50 parts; further, a preparation method thereof comprises the following steps:

[0038] S1, adding deionized water, auxiliary agent, and hydrophobic fumed silica into a stirring tank, stirring and mixing to disperse uniformly;

[0039] S2, mixing the elastic acrylic emulsion, styrene-acrylic emulsion, film-forming agent, and pH regulator, and stirring, and in the stirring process, adding the mixture obtained in S1;

[0040] S3, adding the crosslinking agent, aerogel particles, and modified hollow glass microbeads to the product obtained in S2, stirring uniformly to obtain the water-based aerogel thermal insulation heavy-duty mid-coat paint.

[0041] Further, the particle size of the aerogel particles is 600 μm.

[0042] In some embodiments, the auxiliary agent comprises a bactericide, a high-molecular dispersant, a wetting agent, and a defoaming agent in a mass ratio of 2:5:5:5;

[0043] Further, the bactericide is one or more of Dow M30 bactericide, Dow LXE bactericide, and domestic BT-30 bactericide; the high-molecular dispersant comprises one or more of Shendu SN-2330 dispersant, Tianyu TY-ZJ01 dispersant, and Diguo FX600 dispersant; the wetting agent comprises one or more of TEGO 4100 wetting agent, PE-100 wetting agent, and X-405 wetting agent; and the defoaming agent is Shengnuopu SN-NXZ defoaming agent.

[0044] In some embodiments, the hydrophobic fumed silica comprises one or more of Wanjing R972 fumed silica, Hui Fu HB151 fumed silica, and Huating HT812 fumed silica.

[0045] In some embodiments, the styrene-acrylic emulsion is one or more of Bardac RS-991N, Bardac RS-9987, Dow IC-1002, and Sunrise RC-6008A.

[0046] In some embodiments, the pH adjuster is one or more of AMP-95, DMEA, triethanolamine, and ammonia.

[0047] In some embodiments, the elastic styrene-acrylic emulsion includes deionized water, a composite monomer, an initiator, an emulsifier, NaHCO3, and ammonia in a mass ratio of 50:47.5:1.8:1.2:1:1, and a preparation method thereof includes the following steps:

[0048] a. The emulsifier is mixed with deionized water in a ratio of 3:1, and then the composite monomer is added into a three-necked flask, and then high-speed stirring is performed for 30 min to obtain a pre-emulsion;

[0049] b. One-fifth of the pre-emulsion is added into a four-necked flask, and then NaHCO3 and one-third of the initiator are added into the four-necked flask, nitrogen is blown for half an hour to remove air, and then the temperature is raised to 80°C, the stirring speed is adjusted to 400 r / min, and the reaction is performed until blue light appears under the condition of condensate water;

[0050] c. The remaining pre-emulsion is added dropwise into the product obtained in step b. within 3 h, one-third of the initiator is added in six times during the reaction, after the dropwise addition is completed, the temperature is maintained for 3 h, and then the remaining initiator is added, the reaction is terminated after 20 min, the pH adjuster is added to adjust the pH value of the emulsion to 8-9, and the obtained milky white flooding light liquid is the target emulsion (elastic styrene-acrylic emulsion).

[0051] In the preparation of the elastic styrene-acrylic emulsion, the pH adjuster is ammonia.

[0052] In some embodiments, the composite monomer includes hard monomers, soft monomers, and functional monomers in a mass ratio of 8:10:1.

[0053] The hard monomer is one or more of styrene St, methyl methacrylate MMA, and acrylic AN, the soft monomer is one or more of isooctyl acrylate 2-EHA, butyl acrylate BA, and ethyl acrylate EA, and the functional monomer is one or more of glycidyl methacrylate GMA, isobornyl acrylate IBOA, and hydroxypropyl acrylate HPA.

[0054] In some embodiments, the emulsifier is one or more of sodium dodecyl benzene sulfonate SDBS, dodecyl phenol polyoxyethylene ether OP-10, and fatty alcohol polyoxyethylene ether AEO-9.

[0055] In some embodiments, the initiator is one or more of ammonium persulfate APS, potassium persulfate KPS, sodium persulfate SPS, and sodium salt of organic sulfinic acid FF6M.

[0056] Further, the preparation method of the modified hollow glass microsphere comprises:

[0057] After the hollow glass microspheres are cleaned with acetone or ethanol, the hollow glass microspheres and γ-aminopropyl triethoxysilane are added into a 25% ethanol solution in a mass ratio of 100:1, and a modifier is added after being uniformly mixed, and stirred at 1500-2000 rpm for 10 min to obtain the modified hollow glass microspheres.

[0058] Further, the modifier comprises water-based polyurethane resin, aminoethyl phosphinic acid, tannic acid, and deionized water, and the mass ratio of the water-based polyurethane resin, aminoethyl phosphinic acid, tannic acid, and deionized water is (5-8):(1-2):(0-1):100.

[0059] In some embodiments, the hollow glass microspheres comprise one or more of Saint-Gobain HL15, HL20, HL25, and HL30 glass microspheres, and the specific source is Zhengzhou Saint-Gobain Hollow Glass Microspheres Co., Ltd.

[0060] The aerogel particles used in the following examples are aerogel particles with a particle size of 600 μm from Suzhou Zhongxu Nanometer.

[0061] Embodiment 1

[0062] According to the mass fraction, and each mass part is 50 g, the water-based aerogel heat-insulating thick intermediate coating provided in the embodiment comprises:

[0063] Modified hollow glass microspheres 13 parts, aerogel particles with a particle size of 600 μm 7 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion (BDF RS-991N) 22 parts, Evonik R972 fumed silica 0.5 parts, Dow M30 bactericide 0.2 parts, Shendu SN-2330 dispersant 0.5 parts, TEGO 4100 wetting agent 0.5 parts, Sancopco SN-NXZ defoamer 0.5 parts, 12 nm microcrystalline cellulose 1.5 parts, dipentyl phthalate DPNB 1.5 parts, Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, and deionized water 46 parts.

[0064] According to the mass fraction, and one part is 30 g, wherein the elastic acrylic emulsion comprises: deionized water 50 parts, styrene St 20 parts, isooctyl acrylate 2-EHA 25 parts, glycidyl methacrylate GMA 2.5 parts, initiator (ammonium persulfate) 1.8 parts, sodium dodecyl benzene sulfonate 1.2 parts, NaHCO3 1 part, and ammonia 1 part.

[0065] The preparation method of the water-based aerogel thermal insulation thick intermediate coating is as follows:

[0066] S401, 46 parts of deionized water, 0.2 parts of Dow M30 bactericide, 0.5 parts of Shendu SN-2330 dispersant, 0.5 parts of TEGO 4100 wetting agent, 0.5 parts of Sainuo SN-NXZ defoamer and 0.5 parts of Wincrete R972 fumed silica were added into a stirring tank, stirred and mixed to be uniformly dispersed;

[0067] S402, 5 parts of elastic acrylic emulsion, 22 parts of styrene-acrylic emulsion, 1.5 parts of dipentyl phthalate DPNB and 0.3 parts of Wacker BS168 multifunctional odor removal pH regulator were mixed and stirred, and during the stirring process, the mixture obtained in S401 was added;

[0068] S403, 1.5 parts of microcrystalline cellulose, 7 parts of aerogel particles with a particle size of 600 μm and 13 parts of modified hollow glass microbeads were added into the product obtained in S402, and stirred uniformly to obtain a water-based aerogel thermal insulation thick intermediate coating.

[0069] The preparation method of the elastic acrylic emulsion is as follows:

[0070] a. Sodium dodecyl benzene sulfonate and deionized water were mixed and then added into a three-necked flask, then composite monomers were added, and high-speed stirring was carried out for 30 min to obtain a pre-emulsion;

[0071] b. 1 / 5 of the pre-emulsion was taken and added into a four-necked flask, then NaHCO3 and 1 / 3 of ammonium persulfate were added therein, nitrogen was blown for half an hour to remove air, then the temperature was raised to 80℃, the stirring speed was adjusted to 400 r / min, and the reaction was carried out under the condition of condensing water until blue light appeared;

[0072] c. The remaining pre-emulsion was added dropwise into the product obtained in step b, and the dropping was completed within 3 h, 1 / 3 of ammonium persulfate was added in 6 times during the reaction, after the dropping was completed, the temperature was kept for 3 h, then the remaining ammonium persulfate was added, the reaction was terminated after 20 min, ammonia water was added to adjust the pH value of the emulsion to 8.5, and the obtained milky white flood light liquid was the target emulsion (elastic acrylic emulsion).

[0073] The preparation method of the modified hollow glass microbead includes:

[0074] After the hollow glass microbead was cleaned with ethanol, 700 g of hollow glass microbead (Saint Lite HL25) and 7 g of γ-aminopropyl triethoxysilane were added into a 25% ethanol solution (the amount was just enough to cover the hollow glass microbead), and after drying, pretreated microbeads were obtained;

[0075] The pretreated microbeads were dispersed in deionized water, mixed with 42 g of aqueous polyurethane resin (solid content 50%, solvent deionized water), 10.5 g of aminoethyl phosphinic acid, and 1.4 g of tannic acid, stirred at 1500 rpm for 10 min to obtain modified hollow glass microbeads.

[0076] Example 2

[0077] The water-based aerogel thermal insulation heavy intermediate coating provided in this embodiment includes, in terms of mass parts, and each mass part being 50 g:

[0078] Modified hollow glass microbeads 12 parts, aerogel particles with a particle size of 600 μm 8 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion (Bardrich RS-9987) 25 parts, Hui Fu HB151 fumed silica 0.5 parts, Dow LXE biocide 0.2 parts, Tianyu TY-ZJ01 dispersant 0.5 parts, PE-100 wetting agent 0.5 parts, Sainopec SN-NXZ defoamer 0.5 parts, 10 nm microcrystalline cellulose 1 part, dipropylene glycol methyl ether 1.5 parts, Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, and deionized water 45 parts.

[0079] In terms of mass parts, and one part being 30 g, the elastic acrylic emulsion includes: deionized water 50 parts, methyl methacrylate GMA 20 parts, butyl acrylate BA 25 parts, isobornyl acrylate IBOA 2.5 parts, potassium persulfate 1.8 parts, dodecyl phenol polyoxyethylene ether 1.2 parts, NaHCO3 1 part, and ammonia 1 part.

[0080] The preparation method of the water-based aerogel thermal insulation heavy intermediate coating is as follows:

[0081] S201, add deionized water 45 parts, Dow LXE biocide 0.2 parts, Tianyu TY-ZJ01 dispersant 0.5 parts, PE-100 wetting agent 0.5 parts, Sainopec SN-NXZ defoamer 0.5 parts, and Hui Fu HB151 fumed silica 0.5 parts to a stirring tank, stir and mix to disperse uniformly;

[0082] S202, mix the elastic acrylic emulsion 5 parts, the styrene-acrylic emulsion 25 parts, the dipropylene glycol methyl ether 1.5 parts, and the Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, stir, and in the stirring process, add the mixture obtained in S201;

[0083] S203, add microcrystalline cellulose 1 part, aerogel particles with a particle size of 600 μm 8 parts, and modified hollow glass microbeads 12 parts to the product obtained in S202, stir uniformly to obtain the water-based aerogel thermal insulation heavy intermediate coating.

[0084] The preparation method of the elastic acrylic emulsion is as follows:

[0085] a. Mix dodecylphenol polyoxyethylene ether and deionized water in a ratio of 3:1 and add the mixture to a three-necked flask. Then add the composite monomer and stir at high speed for 30 minutes to obtain a pre-emulsion.

[0086] b. Add 1 / 5 of the pre-emulsion to a four-necked flask, then add NaHCO3 and 1 / 3 of potassium persulfate. Purge with nitrogen for half an hour to remove air, then heat to 80°C and adjust the stirring speed to 400 r / min. React under cooling water conditions until blue light appears.

[0087] c. Add the remaining pre-emulsion to the product obtained in step b, and finish adding it over 3 hours. During the reaction, add 1 / 3 of the potassium persulfate in 6 portions. After the addition is complete, keep the temperature at 45°C for 3 hours, then add the remaining potassium persulfate. Terminate the reaction after 20 minutes, add ammonia to adjust the pH of the emulsion to 8.3. The resulting milky white, luminous liquid is the target emulsion (elastic acrylic emulsion).

[0088] Methods for preparing modified hollow glass microspheres include:

[0089] After cleaning the hollow glass microspheres with acetone, 600g of hollow glass microspheres (Saint-Lait HL15) and 6g of γ-aminopropyltriethoxysilane were added to a 25% ethanol solution (the amount of ethanol should cover the hollow glass microspheres). After drying, the pretreated microspheres were obtained.

[0090] The pretreated microspheres were dispersed in deionized water and mixed with 48g of waterborne polyurethane resin (50% solid content, deionized water as solvent) and 6g of aminoethylphosphonic acid. The mixture was stirred at 1800rpm for 10min to obtain modified hollow glass microspheres.

[0091] Example 3

[0092] The difference from Example 1 is that, according to parts by weight, with each part by weight being 50g, the water-based aerogel insulating thick intermediate coating provided in this example comprises:

[0093] Modified hollow glass microspheres 12 parts, aerogel particles with a particle size of 600 μm 7 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion (Dow IC-1002 and sunrise RC-6008A, mixed at 1:1) 22 parts, Huate HT812 fumed silica 0.5 parts, domestic BT-30 bactericide 0.2 parts, Degao FX600 dispersant 0.5 parts, X-405 wetting agent 0.5 parts, Sainopec SN-NXZ defoamer 0.5 parts, 20 nm microcrystalline cellulose 2 parts, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate 1 part, Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, and deionized water 50 parts.

[0094] According to the mass fraction, and one part is 30g, wherein the elastic acrylic emulsion includes: deionized water 50 parts, acrylonitrile 20 parts, ethyl acrylate EA 25 parts, hydroxypropyl acrylate HPA 2.5 parts, initiator (mixture of sodium persulfate SPS and organic sodium sulfinate FF6M, mass ratio 1:1) 1.8 parts, fatty alcohol polyoxyethylene ether AEO-9 1.2 parts, NaHCO3 1 part, ammonia 1 part.

[0095] The preparation method of the water-based aerogel thermal insulation thick intermediate coating is as follows:

[0096] S301, add deionized water 50 parts, domestic BT-30 bactericide 0.2 parts, Degao FX600 dispersant 0.5 parts, X-405 wetting agent 0.5 parts, Sainopec SN-NXZ defoamer 0.5 parts and Huate HT812 fumed silica 0.5 parts into a stirring tank, stir and mix and disperse uniformly;

[0097] S302, mix the elastic acrylic emulsion 5 parts, the styrene-acrylic emulsion 22 parts, the 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate 1 part and the Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, then stir, and in the stirring process, add the mixture obtained in S301;

[0098] S303, add microcrystalline cellulose 2 parts, aerogel particles with a particle size of 600 μm 7 parts and modified hollow glass microspheres 12 parts to the product obtained in S302, stir uniformly to obtain the water-based aerogel thermal insulation thick intermediate coating.

[0099] The preparation method of the elastic acrylic emulsion is as follows:

[0100] a, mix the fatty alcohol polyoxyethylene ether AEO-9 with deionized water in a ratio of 3:1, then add to a three-necked flask, then add the composite monomer, and stir at high speed for 30 min to obtain a pre-emulsion;

[0101] b. Take 1 / 5 of the pre-emulsified liquid and add it to a four-necked flask, then add NaHCO3 and 1 / 3 of the initiator into it, and then purify it with nitrogen for half an hour to remove air, and then increase the temperature to 80℃, adjust the stirring speed to 400r / min, and then react until blue light appears under the condition of condensing water;

[0102] c. Add the remaining pre-emulsified liquid to the product obtained in step b dropwise, and drop it within 3h, and then add 1 / 3 of the initiator in 6 times during the reaction, and then after the dropwise addition is completed, the temperature is reduced to 45℃ after 3h, and then the remaining initiator is added, and then the reaction is terminated after 20min, and then ammonia water is added to adjust the pH value of the emulsion to 8.4, and then the obtained milky white flood light liquid is the target emulsion (elastic acrylic emulsion).

[0103] The preparation method of the modified hollow glass microbeads comprises the following steps:

[0104] After the hollow glass microbeads are cleaned with ethanol, 600g of the hollow glass microbeads (Saint Light HL20) and 6g of γ-aminopropyl triethoxysilane are added into a 25% ethanol solution (the amount is enough to cover the hollow glass microbeads), and then the pretreated microbeads are obtained after drying.

[0105] The pretreated microbeads are dispersed in deionized water, and then mixed with 36g of the water-based polyurethane resin (solid content 50%, solvent is deionized water), 12g of aminoethyl phosphinic acid and 6g of tannic acid, and then stirred at a speed of 2000rpm for 10min to obtain the modified hollow glass microbeads.

[0106] Example 4

[0107] According to the mass fraction, and each mass part is 50g, the water-based aerogel thermal insulation thick intermediate coating provided in the embodiment comprises:

[0108] Modified hollow glass microbeads 14 parts, aerogel particles with a particle size of 600μm 6 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion (Bafu RS-991N) 25 parts, Yincui R972 fumed silica 0.5 parts, Dow M30 bactericide 0.2 parts, Shendu SN-2330 dispersant 0.5 parts, TEGO 4100 wetting agent 0.5 parts, Saint Nopco SN-NXZ defoamer 0.5 parts, dipentyl phthalate DPNB 1.5 parts, Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, and deionized water 46 parts.

[0109] According to the mass fraction, and one part is 30g, wherein the elastic acrylic emulsion comprises: deionized water 50 parts, styrene St 20 parts, isooctyl acrylate 2-EHA 25 parts, glycidyl methacrylate GMA 2.5 parts, ammonium persulfate 1.8 parts, sodium dodecyl benzene sulfonate 1.2 parts, NaHCO3 1 part, and ammonia water 1 part.

[0110] The preparation method of the water-based aerogel thermal insulation thick intermediate coating is as follows:

[0111] S401, 46 parts of deionized water, 0.2 parts of Dow M30 bactericide, 0.5 parts of Shendu SN-2330 dispersant, 0.5 parts of TEGO 4100 wetting agent, 0.5 parts of Sainofo SN-NXZ defoamer and 0.5 parts of Wincreate R972 fumed silica are added into a stirring tank, stirred and mixed to be uniformly dispersed;

[0112] S402, 5 parts of elastic acrylic emulsion, 25 parts of styrene-acrylic emulsion, 1.5 parts of dipentyl phthalate and 0.3 parts of Wacker BS168 multifunctional odor-free pH regulator are mixed and stirred, and during the stirring process, the mixture obtained in S401 is added;

[0113] S403, 6 parts of aerogel particles with a particle size of 600 μm and 14 parts of modified hollow glass microspheres are added into the product obtained in S402, and stirred uniformly to obtain a water-based aerogel thermal insulation thick intermediate coating.

[0114] The preparation method of the elastic acrylic emulsion is as follows:

[0115] a. Sodium dodecyl benzene sulfonate and deionized water are mixed in a ratio of 3:1 and then added into a three-necked flask, then the composite monomer is added, and high-speed stirring is carried out for 30 min to obtain a pre-emulsion;

[0116] b. 1 / 5 of the pre-emulsion is taken and added into a four-necked flask, then NaHCO3 and 1 / 3 of ammonium persulfate are added therein, nitrogen gas is passed for half an hour to expel air, then the temperature is raised to 80℃, the stirring speed is adjusted to 400 r / min, and the reaction is carried out under the condition of passing condensed water until blue light appears;

[0117] c. The remaining pre-emulsion is added dropwise into the product obtained in step b, and the dropping is completed within 3 h, 1 / 3 of ammonium persulfate is added in 6 times during the reaction, after the dropping is completed, the temperature is kept for 3 h, then the remaining ammonium persulfate is added, the reaction is terminated after 20 min, ammonia water is added to adjust the pH value of the emulsion to 8.5, and the obtained milky white flooding light liquid is the target emulsion (elastic acrylic emulsion).

[0118] The preparation method of the modified hollow glass microspheres includes:

[0119] After the hollow glass microspheres are cleaned with ethanol, 700 g of hollow glass microspheres (Saint Light HL15 and Saint Light HL30 mixed in a mass ratio of 1:1) and 7 g of γ-aminopropyl triethoxysilane are added into a 25% ethanol solution (the amount covers the hollow glass microspheres), and after drying, pretreated microspheres are obtained;

[0120] The pretreated microbeads were dispersed in deionized water, mixed with 35 g of aqueous polyurethane resin (solid content 50%, solvent deionized water), 7 g of aminoethyl phosphinic acid, stirred at 1800 rpm for 10 min, and the modified hollow glass microbeads were obtained.

[0121] Example 5

[0122] The difference between this embodiment and example 1 is that the water-based aerogel thermal insulation thick intermediate coating provided by this embodiment includes, in terms of mass parts, and each mass part is 50 g:

[0123] Modified hollow glass microbeads 14 parts, aerogel particles with a particle size of 600 μm 7 parts, elastic acrylic emulsion 5 parts, styrene-acrylic emulsion (Bafu RS-991N) 20 parts, Wacker R972 fumed silica 0.5 parts, Dow M30 bactericide 0.2 parts, Shendu SN-2330 dispersant 0.5 parts, TEGO 4100 wetting agent 0.5 parts, Sainofo SN-NXZ defoamer 0.5 parts, 12 nm microcrystalline cellulose 0.5 parts, dipentyl phthalate DPNB 1.5 parts, Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, and deionized water 46 parts.

[0124] The preparation method of the water-based aerogel thermal insulation thick intermediate coating is as follows:

[0125] S201, add 46 parts of deionized water, 0.2 parts of Dow M30 bactericide, 0.5 parts of Shendu SN-2330 dispersant, 0.5 parts of TEGO 4100 wetting agent, 0.5 parts of Sainofo SN-NXZ defoamer, and 0.5 parts of Wacker R972 fumed silica into a stirring tank, and stir and mix to disperse uniformly;

[0126] S202, mix the elastic acrylic emulsion 5 parts, the styrene-acrylic emulsion 20 parts, the dipentyl phthalate DPNB 2 parts, and the Wacker BS168 multifunctional odor removal pH adjuster 0.3 parts, stir, and add the mixture obtained in S201 during stirring;

[0127] S203, add 0.5 parts of microcrystalline cellulose, 7 parts of aerogel particles with a particle size of 600 μm, and 14 parts of modified hollow glass microbeads to the product obtained in S202, stir uniformly, and obtain the water-based aerogel thermal insulation thick intermediate coating.

[0128] The preparation method of the modified hollow glass microbeads includes:

[0129] After cleaning the hollow glass microbeads with ethanol, 700 g of hollow glass microbeads (Saint Lite HL25) and 7 g of γ-aminopropyl triethoxysilane were added to a 25% ethanol solution (the amount was just enough to cover the hollow glass microbeads), and after drying, pretreated microbeads were obtained;

[0130] The pretreated microbeads were dispersed in deionized water, mixed with 42 g of an aqueous polyurethane resin (solid content 50%, solvent deionized water), 7 g of aminoethyl phosphinic acid, and 3.5 g of tannic acid, and stirred at a speed of 1500 rpm for 10 min to obtain modified hollow glass microbeads.

[0131] Comparative Example 1

[0132] The water-based aerogel thermal insulation heavy-duty mid-coat paint provided by the present comparative example includes, by mass fraction and with each mass fraction being 50 g:

[0133] Modified hollow glass microbeads 13 parts, aerogel slurry with an effective component of 20% made of aerogel powder with a particle size of 50 μm 30 parts, styrene-acrylic emulsion 27 parts, Wacker R972 fumed silica 0.5 parts, Dow M30 bactericide 0.2 parts, Shendu SN-2330 dispersant 0.5 parts, TEGO 4100 wetting agent 0.5 parts, Sancrope SN-NXZ defoamer 0.5 parts, 12 nm microcrystalline cellulose 1.5 parts, dipentyl phthalate DPNB 1.5 parts, Wacker BS168 multifunctional odor control pH adjuster 0.3 parts, and deionized water 46 parts.

[0134] The method for preparing modified hollow glass microbeads is as in Example 1.

[0135] The method for preparing the water-based aerogel thermal insulation heavy-duty mid-coat paint is as follows:

[0136] S1, add deionized water 46 parts, Dow M30 bactericide 0.2 parts, Shendu SN-2330 dispersant 0.5 parts, TEGO 4100 wetting agent 0.5 parts, Sancrope SN-NXZ defoamer 0.5 parts, and Wacker R972 fumed silica 0.5 parts to a stirring tank, and stir and mix to disperse uniformly;

[0137] S2, mix styrene-acrylic emulsion 27 parts, dipentyl phthalate DPNB 1.5 parts, and Wacker BS168 multifunctional odor control pH adjuster 0.3 parts, and stir, and in the process of stirring, add the mixture obtained in S1;

[0138] S3, add microcrystalline cellulose 1.5 parts, aerogel slurry with an effective component of 20% made of aerogel powder with a particle size of 50 μm 30 parts, and modified hollow glass microbeads 13 parts to the product obtained in S2, and stir uniformly to obtain the water-based aerogel thermal insulation heavy-duty mid-coat paint.

[0139] That is, compared with Example 1, 7 parts of aerogel particles with a particle size of 600 μm are replaced by 35 parts of aerogel slurry with an effective component of 20% made of aerogel powder with a particle size of 50 μm, no elastic acrylic emulsion is used, and the fraction of styrene-acrylic emulsion is adjusted to 27 parts.

[0140] Comparative Example 2

[0141] The difference between this comparative example and Example 2 is that 8 parts of aerogel particles with a particle size of 600 μm are replaced with 40 parts of an aerogel slurry with an active ingredient of 20% made of aerogel powder with a particle size of 50 μm, and no elastic acrylic emulsion is used, and the number of parts of the styrene-acrylic emulsion is adjusted to 30 parts.

[0142] Comparative Example 3

[0143] The difference between this comparative example and Example 3 is that 7 parts of aerogel particles with a particle size of 600 μm are replaced with 35 parts of an aerogel slurry with an active ingredient of 20% made of aerogel powder with a particle size of 50 μm, and no elastic acrylic emulsion is used, and the number of parts of the styrene-acrylic emulsion is adjusted to 27 parts.

[0144] Comparative Example 4

[0145] The difference between this comparative example and Example 1 is that no fumed silica is added.

[0146] Comparative Example 5

[0147] The difference between this comparative example and Example 1 is that 7 parts of aerogel particles with a particle size of 600 μm are replaced with 35 parts of an aerogel slurry with an active ingredient of 20% made of aerogel powder with a particle size of 50 μm, and no fumed silica is added.

[0148] Comparative Example 6

[0149] The difference between this comparative example and Example 1 is that no elastic acrylic emulsion is used, and the number of parts of the styrene-acrylic emulsion is adjusted to 27 parts.

[0150] Comparative Example 7

[0151] The difference between this comparative example and Example 1 is that the hollow glass microspheres are not modified.

[0152] Examples 1-5 and Comparative Examples 1-7 are tested for adhesive strength and thermal conductivity coefficient according to the requirements in TCECS10126-2021 Aerogel Insulation Thick Coating System, and 30-day storage stability is measured, and the results are shown in Table 1.

[0153] Table 1

[0154]

[0155]

[0156] The adhesive strength of each embodiment and comparative example is greater than 0.6, meeting the requirement of adhesive strength in TCECS10126-2021 "Aerogel thermal insulation thick coating system", that is, using aerogel particles instead of aerogel powder does not affect the adhesive strength of the paint film.

[0157] Through the comparison of the thermal conductivity of Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 3 and Comparative Example 3, it is analyzed that using aerogel particles instead of aerogel powder can bring lower thermal conductivity to the coating.

[0158] Through the comparison of Example 1 and Comparative Example 4 and Comparative Example 5, it is analyzed that fumed silica can not only effectively prevent the coating from delamination and maintain good construction state, but also improve the adhesive strength between thick intermediate paint and substrate.

[0159] Through the comparison of Example 1 and Comparative Example 6, it is analyzed that the combination of elastic acrylic emulsion and styrene-acrylic emulsion can effectively solve the problem of poor flexibility of the coating after adding aerogel particles.

[0160] Through the comparison of Example 1 and Comparative Example 7, it is analyzed that the modified hollow glass beads can promote the combination of its interface with elastic acrylic emulsion and styrene-acrylic emulsion, form a cross-linked network, and improve the strength of the coating.

[0161] Further referring to Figure 2 , which are SEM images of Example 2 and Comparative Example 2 at different magnifications.

[0162] Among them Figure 2 , a, b and c are SEM images of the water-based aerogel thermal insulation thick intermediate paint made of aerogel particles with a particle size of 600 μm in Example 2 at magnifications of 50 times, 100 times and 1000 times, Figure 2 , d, e and f are SEM images of the water-based aerogel thermal insulation thick intermediate paint made of aerogel powder with a particle size of 50 μm in Comparative Example 2 at magnifications of 50 times, 100 times and 1000 times.

[0163] Firstly, compare Figure 2 a and Figure 2 d at 50 times, Figure 2 b and Figure 2 e at 100 times, Figure 2 b not only can see the hollow glass beads cut by the blade when making the section, but also can see the internal complete hollow glass beads through the larger holes than the latter, while Figure 2 e can only see the surface hollow glass beads cut by the blade due to the dense paint film; Figure 2 c and Figure 2As shown in f, the pores in the former are much larger than those in the latter, and the paint film in the latter is denser. Comparing the SEM images of the two at different magnifications clearly reveals the reason for the difference in thermal conductivity, further proving the advantage of using aerogel particles.

[0164] Furthermore, the service temperature of the waterborne aerogel insulating thick intermediate coating prepared in Example 1 was determined by simultaneous thermal analysis (TG-DSC) under air atmosphere conditions. The curve of the simultaneous thermal analysis is shown below. Figure 2 As shown. From Figure 3 Figure 3 It can be seen that the TG curve is nearly parallel to the X-axis in the range of 0–120℃, indicating that the coating remains essentially unchanged. The minimal weight loss is due to the evaporation of adsorbed water, proving that this waterborne aerogel insulating thick intermediate coating can operate stably below 120℃. Above 120℃, the weight loss rate of the coating begins to increase, primarily due to film-forming agents adsorbed in the aerogel pores, and also partly due to slight gelatinization of the emulsion, mainly caused by the breaking of oligomer bonds and partial vaporization. After 223.87℃, the weight loss of the coating accelerates further. After 600℃, the coating almost stops losing weight, with a weight loss rate of approximately 51%. Observing the DTG curve, peaks are observed at 353.34℃ and 486.44℃, corresponding to two exothermic behaviors in the DSC curve. These are analyzed to be the rapid exothermic oxidation of acrylic resin formed by the elastic acrylic emulsion film formation and the hydrophobic groups on the surface of the 600μm aerogel particles in air.

[0165] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A water-based aerogel thermal insulation thick intermediate coating, characterized in that, According to parts by weight, it includes: 12-14 parts modified hollow glass microspheres, 6-8 parts aerogel particles, 5 parts elastic acrylic emulsion, 20-25 parts styrene-acrylic emulsion, 0.5 parts hydrophobic fumed silica, 0-2 parts crosslinking agent, 2 parts additives, 1-2 parts film-forming agent, 0.3 parts pH adjuster, and 45-50 parts deionized water. The aerogel particles have a particle size of 600 μm; The elastic acrylic emulsion comprises deionized water, composite monomers, initiator, emulsifier, NaHCO3 and ammonia in a mass ratio of 50:47.5:1.8:1.2:1:

1. The composite monomer comprises hard monomers, soft monomers, and functional monomers in a mass ratio of 8:10:

1. The hard monomer is one or more of styrene, methyl methacrylate and acrylonitrile; the soft monomer is one or more of isooctyl acrylate, butyl acrylate and ethyl acrylate; and the functional monomer is one or more of glycidyl methacrylate, isobornyl acrylate and hydroxypropyl acrylate. The crosslinking agent is microcrystalline cellulose, and the microcrystalline cellulose has a diameter of 10~20 nm. The method for preparing the modified hollow glass microspheres includes: After cleaning the hollow glass microspheres with acetone or ethanol, add the hollow glass microspheres and γ-aminopropyltriethoxysilane to a 25% ethanol solution at a mass ratio of 100:

1. After mixing evenly, add the modifier and stir at 1500~2000 rpm for 10 min to obtain modified hollow glass microspheres. The modifier includes waterborne polyurethane resin, aminoethylphosphonic acid, tannic acid and deionized water, and the mass ratio of the waterborne polyurethane resin, aminoethylphosphonic acid, tannic acid and deionized water is (5~8):(1~2):(0~1):

100.

2. The water-based aerogel thermal insulation thick intermediate coating as described in claim 1, characterized in that: In the elastic acrylic emulsion, the emulsifier is one or more of sodium dodecylbenzenesulfonate, dodecylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

3. The water-based aerogel thermal insulation thick intermediate coating as described in claim 1, characterized in that: The additives include bactericides, polymeric dispersants, wetting agents, and defoamers in a mass ratio of 2:5:5:

5.

4. The water-based aerogel thermal insulation thick intermediate coating as described in claim 1, characterized in that: The film-forming agent includes one or more of DPNB, DPM and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

5. A method for preparing a water-based aerogel insulating thick intermediate coating, characterized in that, It is used to prepare the water-based aerogel thermal insulation thick intermediate coating as described in any one of claims 1 to 4, and the preparation method includes the following steps: S1. Add deionized water, additives and hydrophobic fumed silica into a mixing tank, stir and mix until evenly dispersed; S2. Mix the elastic acrylic emulsion, styrene-acrylic emulsion, film-forming agent and pH adjuster and stir. During the stirring process, add the mixture obtained in S1. S3. Add crosslinking agent, aerogel particles and modified hollow glass microspheres to the product obtained in S2, stir evenly to obtain water-based aerogel thermal insulation thick intermediate coating.

6. The method for preparing the water-based aerogel insulating thick intermediate coating as described in claim 5, characterized in that: The preparation method of the elastic acrylic emulsion includes the following steps: a. Mix the emulsifier with deionized water and add it to a three-necked flask. Then add the composite monomer and stir together at high speed for 30 minutes to obtain a pre-emulsion. b. Add 1 / 5 of the pre-emulsion to a four-necked flask, then add NaHCO3 and 1 / 3 of the initiator, purge with nitrogen for half an hour to remove air, then heat to 80°C, adjust the stirring speed to 400 r / min, and react under the condition of purging with cooling water until blue light appears. c. Add the remaining pre-emulsion to the product obtained in step b, and finish adding it over 3 hours. During the reaction, add 1 / 3 of the initiator in 6 portions. After the addition is complete, keep the temperature at 45°C for 3 hours, then add the remaining initiator. Terminate the reaction after 20 minutes, add ammonia to adjust the pH of the emulsion to 8-9. The resulting milky white, luminous liquid is the elastic acrylic emulsion.

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