A water-based heat-reflective thermal insulation coating and a preparation method thereof

Abstract

The present application relates to the field of heat-reflecting thermal insulation finish, and particularly relates to a water-based heat-reflecting thermal insulation coating and a preparation method thereof, raw materials of the coating include, by mass fraction, water-based nano-silica sol-acrylic acid emulsion 45-55 parts, water-based nano-TiO2 modified hollow glass microsphere slurry 7-15 parts, nano-ATO modified ceramic microsphere 12-18 parts, titanium white powder 5-9 parts, filler 8-15 parts, water 3-11 parts, and other additives 1.7-5.2 parts.The coating has excellent corrosion resistance and weather resistance, and the performance of the matching coating, such as acid resistance (>=72h) and alkali resistance (>=72h), meets the index requirements, the finish coating has artificial aging resistance >=500h, meets the requirement of long-term outdoor protection, and can be used for the outer wall of a crude oil storage tank.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of heat-reflecting thermal insulation finish, in particular to a water-based heat-reflecting thermal insulation coating and a preparation method thereof. BACKGROUND

[0002] The heat-reflecting thermal insulation coating is a coating with high solar reflectance and high infrared emissivity, which can reflect high in the solar infrared light range and visible light range of 400nm-2500nm, and can automatically radiate heat to reduce the temperature of the object. At the same time, the function filler with extremely low thermal conductivity in the coating plays a heat insulation function, ensuring that the internal space of the object can maintain a lower temperature.

[0003] If the outer surface of the tank and equipment such as oil storage tank and liquefied natural gas (LNG) storage tank is not protected by heat-reflecting thermal insulation coating, not only energy loss will occur, but also serious safety accidents such as fire and explosion may occur. Among the heat-reflecting thermal insulation coatings, the water-based heat-reflecting thermal insulation coating is a simple and effective energy-saving material, and has become a research and development hotspot.

[0004] At present, the fillers in the heat-reflecting thermal insulation coatings on the market mostly use hollow glass microbeads, titanium dioxide, ceramic microspheres, etc. These fillers play the functions of heat insulation, reinforcement, and solar light reflection. For example, Chinese patent document CN114456659A discloses a solar heat-reflecting thermal insulation coating and a preparation method thereof, which uses modified rutile titanium dioxide and hollow glass microbeads as the main light-emitting coating, which can reflect solar light effectively, and the prepared coating has excellent thermal conductivity and stain resistance. However, in actual application, the water-based heat-reflecting thermal insulation coating coated on the outer surface of the tank and equipment is directly contacted with the external environment, and is affected by cold and hot changes, wind and rain erosion, which puts higher requirements on the weather resistance, corrosion resistance and service life of the water-based heat-reflecting thermal insulation coating. SUMMARY

[0005] To solve the problems of weather resistance, corrosion resistance and service life of the existing heat-reflecting thermal insulation coating, the present application provides a water-based heat-reflecting thermal insulation coating, which comprises, by mass fraction:

[0006]

[0007] It should be noted that ATO refers to antimony tin oxide.

[0008] Further, the other additives include a water-based dispersant, a water-based defoaming agent and a water-based thixotropic agent;

[0009] Preferably, the other additives include 0.8-2 parts of a water-based dispersant, 0.4-1.2 parts of a water-based defoaming agent, and 0.5-2 parts of a water-based thixotropic agent.

[0010] The aqueous dispersant is one or more of BYK-190, BYK-191, Tego747w and Surfynol 104E;

[0011] The aqueous defoamer is one or more of Tego-810, Tego-901w and DAPRO DF1760;

[0012] The aqueous thixotropic agent is one or more of BASF PU1190, RM-8W, RM-12W, Tego-299;

[0013] The filler is one or more of heavy calcium, precipitated barium sulfate, talcum powder and kaolin.

[0014] The titanium white powder is one or more of Longbai R996, Yuxing R818 and Ananda ATR-311;

[0015] Further, the preparation method of the aqueous nano-silica sol-acrylic emulsion comprises the following steps:

[0016] (1) Preparation of modified nano-silica sol: uniformly disperse silica sol, anionic surfactant, distilled water, anionic alcohol ammonium salt solution and first silane coupling agent, then stir and disperse at 45-65℃ for 60-120min to obtain the modified nano-silica sol;

[0017] (2) Mix the modified nano-silica sol, second silane coupling agent and acrylic ester monomer to make the modified nano-silica sol completely dissolved in the acrylic ester monomer to form a mixed solution;

[0018] Stir the mixed solution and emulsion to perform pre-emulsification to obtain a pre-emulsion;

[0019] Mix the pre-emulsion and initiator solution, stir and heat under nitrogen atmosphere and a reaction system pressure of 0.15-0.2MPa, when the temperature reaches 75-90℃, the system appears blue phase, after the blue phase is obvious, keep warm for 20-40min to obtain the aqueous nano-silica sol-acrylic emulsion.

[0020] Further, in the preparation process of the modified nano-silica sol, the ratio of the silica sol, anionic surfactant, anionic alcohol ammonium salt solution, first silane coupling agent and distilled water is (40-60)g:(4-6)g:(0.5-2.5)g:(2.5-4.5)g:(80-120)ml;

[0021] The emulsion is an aqueous solution of emulsifier, and the initiator solution is an aqueous solution of initiator.

[0022] The weight ratio of the modified nanometer silicon sol, the second silane coupling agent, the acrylate monomer, the emulsifier in the emulsion and the initiator in the initiator solution is (5-15) g:(0.4-0.8) g:(40-60) g:(0.5-1.0) g:(0.1-0.5) g;

[0023] The average particle size of the nanometer TiO2 powder is 0.2-0.3 μm.

[0024] Further, the anionic surfactant is one or more of NUOSPERSE FA 115, NUOSPERSE FA 182 and NUOSPERSE FA 620;

[0025] The anionic alcohol amine salt solution is one or more of BYK-151, BYK-154 and BYK-155;

[0026] The acrylate monomer is one or more of (methyl) acrylic acid, methyl acrylate, methyl methacrylate, styrene, acrylonitrile and vinyl acetate;

[0027] The emulsifier is one or more of dodecyl ammonium chloride, cetyl pyridinium bromide, octadecyl amine polyoxyethylene ether bisquaternary ammonium salt and dodecyl dimethyl ammonium chloride;

[0028] The initiator is one or more of benzoyl peroxide, tert-amyl 2-ethylhexyl acid peroxide, tert-butyl 2-ethylhexyl acid peroxide, tert-amyl acetate peroxide and tert-butyl benzoyl peroxide;

[0029] The first silane coupling agent and the second silane coupling agent are one or more of γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, KH-590 and KH-551.

[0030] Further, the preparation method of the aqueous nanometer TiO2 modified hollow glass microsphere slurry includes the following steps:

[0031] (1) Preparation of surface modified TiO2 powder: mix the nanometer TiO2 powder with the mixed solvent, add the third silane coupling agent at 80-100℃, and after the dropwise addition is completed, adjust the temperature to 70-90℃ and react for 2.5-5h; after the reaction, wash and dry to obtain the surface modified TiO2 powder;

[0032] (2) the preparation of the nano-TiO2 modified hollow glass microspheres: the surface modified TiO2 powder, the hollow glass microspheres, the ethylene glycol butyl ether and the first modified polyurethane aqueous solution are mixed uniformly, and then heated to reflux at 110-130℃ for 8-15 min, and after cooling, the nano-TiO2 modified hollow glass microspheres are obtained by filtration and drying;

[0033] (3) the nano-TiO2 modified hollow glass microspheres, the hydroxyethyl cellulose, the deionized water and the first acetylenic diol molecular solution are mixed uniformly, and the aqueous nano-TiO2 modified hollow glass microspheres slurry is obtained.

[0034] Further, in the preparation process of the surface modified TiO2 powder, the mixed solvent is anhydrous ethanol and deionized water mixed at a mass ratio of (8-10):1; the mass ratio of the nano-TiO2 powder, the mixed solvent and the third silane coupling agent is (20-40)g:(90-110)g:(3-7)g;

[0035] In the preparation process of the nano-TiO2 modified hollow glass microspheres, the mass ratio of the surface modified TiO2 powder, the hollow glass microspheres, the ethylene glycol butyl ether and the first modified polyurethane aqueous solution is (40-60)g:(4-6)g:(90-120)ml:(0.5-2.5)g;

[0036] The mass ratio of the nano-TiO2 modified hollow glass microspheres, the hydroxyethyl cellulose, the deionized water and the first acetylenic diol molecular solution is (10-20)g:(1-3)g:(40-60)g:(0.3-0.8)g.

[0037] Further, the preparation method of the nano-ATO modified ceramic microspheres is as follows:

[0038] (1) the SnO2 powder, the Sb2O3 powder, the second modified polyurethane aqueous solution and the deionized water are mixed uniformly, and then wet-milled by a ball mill for 30-40h to obtain a mixture water slurry;

[0039] (2) the ceramic microspheres, the mixture water slurry and the second acetylenic diol molecular solution are dispersed and mixed uniformly for 50-80 min, then the ceramic microbeads are taken out, and after water is removed by suction filtration, the nano-ATO modified ceramic microspheres are obtained by heating to 150℃ and keeping for 2-4h;

[0040] Further, the mass ratio of the SnO2 powder, the Sb2O3 powder, the second modified polyurethane aqueous solution and the deionized water is (92-100)g:(2-6)g:(10-20)g:(40-60)g;

[0041] The mass ratio of the ceramic microspheres, the mixture water slurry and the second acetylene diol molecular solution is (10-20) g:(90-110) g:(0.2-0.8) g.

[0042] Further, the third silane coupling agent is one or more of gamma-aminopropyl triethoxysilane, N-beta-(aminoethyl)-gamma-aminopropyl trimethoxysilane, KH-590 and KH-551.

[0043] The first modified polyurethane aqueous solution is one or more of Borchi Gen0451, Borchi Gen0577 and Tego 760w.

[0044] The first acetylene diol molecular solution and the second acetylene diol molecular solution are one or more of Greesol A04, Greesol G45 and Greesol DF05.

[0045] The application also provides a preparation method of the water-based heat-reflecting thermal insulation coating.

[0046] (1) mixing the water-based nano-silica sol-acrylic emulsion, a part of water, the water-based dispersant and the water-based defoaming agent uniformly to obtain a mixture I;

[0047] (2) mixing the water-based nano-TiO2 modified hollow glass microsphere slurry, the nano-ATO modified ceramic microsphere, the titanium white powder and the filler with the mixture I uniformly, adding the water-based thixotropic agent, and adjusting the viscosity by using the remaining water to obtain the water-based heat-reflecting thermal insulation coating.

[0048] Compared with the prior art, the water-based heat-reflecting thermal insulation coating and the preparation method thereof have the following beneficial effects:

[0049] 1. The water-based heat-reflecting thermal insulation coating provided by the application uses the water-based nano-silica sol-acrylic emulsion as a film-forming material, and adds the water-based nano-TiO2 modified hollow glass microsphere slurry and the nano-ATO modified ceramic microsphere as main thermal insulation fillers, so that the prepared coating not only has the near-infrared reflection ability, the thermal insulation ability and the light weight characteristics of the hollow glass microbead, but also contains the metal oxide ATO (tin antimony oxide) which has the mid-infrared radiation ability, so that the coating layer can maintain a lower temperature under the sun.

[0050] 2. The coating provided by the application simultaneously has excellent corrosion resistance and weather resistance, and the performance of the supporting coating, such as acid resistance (≥72 h), alkali resistance (≥72 h) and the like, meets the index requirements, the topcoat has a service life of artificial aging of ≥500 h, meets the requirements of long-term outdoor protection, and can be used for the outer wall of a crude oil storage tank.

[0051] 3、The coating of the present application is light in weight, and the coating thickness is controllable, energy-saving, environment-friendly, and simple in construction process, and can be applied by manual painting, roller coating, spraying and the like, and has the advantages of low energy consumption and less emission. DETAILED DESCRIPTION

[0052] To make the objectives, 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 below in a clear and complete manner. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0053] The present application provides a kind of water-based heat reflection thermal insulation coating, by mass parts, raw material includes: water-based nano silicon sol-acrylic emulsion 45-55 parts, water-based dispersing agent 0.8-2 parts, water-based defoaming agent 0.4-1.2 parts, water-based nano TiO 2 Modified hollow glass microspheres slurry 7-15 parts, nano ATO modified ceramic microspheres 12-18 parts, titanium white 5-9 parts, filler 8-15 parts, water 3-11 parts, water-based thixotropic agent 0.5-2 parts.

[0054] The present application also provides the preparation method of the above-mentioned water-based heat reflection thermal insulation coating, comprising the following steps:

[0055] (1) take water-based nano silicon sol-acrylic emulsion and add it to a container, add part of water, water-based dispersing agent and water-based defoaming agent into it, disperse at a speed of 400-600 r / min for 10-30 minutes to obtain mixture I;

[0056] (2) under the condition of stirring at a speed of 200-300 r / min, gradually add water-based nano TiO 2 Modified hollow glass microspheres slurry, nano ATO modified ceramic microspheres, titanium white and filler into mixture I, disperse at a speed of 700-900 r / min for 20-40 minutes, after dispersion, add water-based thixotropic agent, adjust the viscosity with the remaining water to obtain water-based heat reflection thermal insulation coating, and then pack by weight.

[0057] The water-based nano silicon sol-acrylic emulsion is prepared by solution polymerization of modified nano silicon sol and water-based acrylic emulsion, and the specific operation is as follows:

[0058] (1) preparation of modified nano silicon sol: uniformly mix silica sol and anionic surfactant, add into a round-bottom flask containing distilled water, drop anionic alcohol ammonium salt solution and silane coupling agent, ultrasonic dispersion for 10-20 min, then stir and disperse at 45-65 DEG C for 60-120 min to obtain the required modified nano silicon sol.

[0059] The ratio of the silicon sol, the anionic surfactant, the anionic alcohol ammonium salt solution, the silane coupling agent and distilled water is (40-60) g:(4-6) g:(0.5-2.5) g:(2.5-4.5) g:(80-120) ml.

[0060] (2) Preparation of the aqueous nano-silicon sol-acrylic emulsion:

[0061] S1, accurately weigh the emulsifier, then add deionized water, heat at 70-90 DEG C for 8-20 min to dissolve the emulsifier to form an emulsion; weigh the initiator, and add deionized water to form an initiation solution;

[0062] The concentration of the emulsion is (0.01-0.024) g / ml, and the concentration of the initiation solution is (0.005-0.02) g / ml.

[0063] S2, take the modified nano-silicon sol prepared in step (1), the silane coupling agent and the acrylic ester monomer, and make the modified nano-silicon sol completely dissolved in the monomer. The dissolved mixture and the emulsion in step S1 are added to a three-necked flask for pre-emulsification under mechanical stirring at a speed of 400-600 r / min. After stirring at room temperature for 0.5-1.5 h, a pre-emulsion is obtained, which is poured out after standing for standby use.

[0064] S3, the initiation solution in step S1 and the pre-emulsion in step S2 are added to a three-necked flask, nitrogen is introduced as a protective gas, the pressure is (0.15-0.2) MPa, slightly higher than atmospheric pressure, and the stirring speed is controlled at 200-400 r / min. When the temperature reaches 75-90 DEG C, the system will slowly appear blue phase. After the blue phase is obvious, heat for 20-40 min to obtain the aqueous nano-silicon sol-acrylic emulsion.

[0065] The weight ratio of the modified nano-silicon sol, the silane coupling agent, the acrylic ester monomer, the emulsifier in the emulsion and the initiator in the initiation solution is (5-15) g:(0.4-0.8) g:(40-60) g:(0.5-1.0) g:(0.1-0.5) g.

[0066] The preparation method of the aqueous nano-TiO2 modified hollow glass microsphere slurry is as follows:

[0067] (1) The nano-TiO2 powder is added to a container containing a mixed solvent, and is dispersed by high-speed stirring for 15-30 min. Then, the silane coupling agent is added at 80-100 DEG C, and the temperature is adjusted to 70-90 DEG C after the dropwise addition is completed, and the reaction is carried out for 2.5-5 h. After the reaction, the modified TiO2 powder is obtained by washing with anhydrous ethanol for 3 times and vacuum drying at 100-140 DEG C.

[0068] The mixed solvent is anhydrous ethanol and deionized water mixed in a mass ratio of (8-10):1.

[0069] The mass ratio of the nano-TiO2 powder, the mixed solvent, and the silane coupling agent is (20-40)g:(90-110)g:(3-7)g.

[0070] (2) The surface-modified TiO2 powder prepared in step (1) is mixed with hollow glass microspheres and added into a round-bottom flask containing ethylene glycol butyl ether, and a modified polyurethane aqueous solution is added dropwise and ultrasonically dispersed for 30-50 min, and then heated and refluxed at 110-130°C for 8-15 min, and then cooled and filtered, and the filter is baked in an oven at 40-60°C for 20-30 h to obtain the desired nano-TiO2 modified hollow glass microspheres;

[0071] The mass ratio of the surface-modified TiO2 powder, the hollow glass microspheres, the ethylene glycol butyl ether, and the modified polyurethane aqueous solution is (40-60)g:(4-6)g:(90-120)ml:(0.5-2.5)g.

[0072] (3) The nano-TiO2 modified hollow glass microspheres prepared in step (2) and hydroxyethyl cellulose are added to deionized water, and then an acetylenic diol molecular solution is added, and dispersed at a speed of 400-600 r / min for 5-10 min to obtain an aqueous nano-TiO2 modified hollow glass microsphere slurry;

[0073] The mass ratio of the nano-TiO2 modified hollow glass microspheres, the hydroxyethyl cellulose, the deionized water, and the acetylenic diol molecular solution is (10-20)g:(1-3)g:(40-60)g:(0.3-0.8)g.

[0074] The preparation method of the nano-ATO modified ceramic microspheres is as follows:

[0075] (1) SnO2 powder, Sb2O3 powder, and a modified polyurethane aqueous solution are added to deionized water, and dispersed at a speed of 300-500 r / min for 5-10 min, and then wet-milled by a ball mill for 30-40 h to obtain a mixture slurry;

[0076] The mass ratio of the SnO2 powder, the Sb2O3 powder, the modified polyurethane aqueous solution, and the deionized water is (92-100)g:(2-6)g:(10-20)g:(40-60)g.

[0077] (2) mixing the ceramic microspheres and the mixture water slurry prepared in step (1), then adding the acetylene glycol molecular solution, dispersing at a rotation speed of 400-600 r / min for 50-80 min, then taking out the ceramic microspheres, removing water by suction filtration, and then heating to 150 DEG C and keeping for 2-4 h to obtain the nano ATO modified ceramic microspheres with an ATO (antimony tin oxide) layer on the surface and a ceramic layer in the inner layer;

[0078] The mass ratio of the ceramic microspheres, the mixture water slurry and the acetylene glycol molecular solution is (10-20) g:(90-110) g:(0.2-0.8) g.

[0079] The application further provides the following examples and comparative examples.

[0080] Example 1

[0081] An aqueous heat-reflecting and heat-insulating coating, raw materials are shown in Table 1

[0082] Table 1

[0083]

[0084]

[0085] The preparation method of the aqueous heat-reflecting and heat-insulating coating is as follows:

[0086] (1) adding the aqueous nano silicon sol-acrylic acid emulsion into a dispersing tank according to the formula amount, adding a part of the third water, the aqueous wetting dispersant BYK-191 and the aqueous defoaming agent Tego-810 according to the formula amount in sequence, and dispersing at a medium speed of 600 r / min for 15 min to obtain a mixture I;

[0087] (2) adding the aqueous nano TiO2 modified hollow glass microspheres slurry, the nano ATO modified ceramic microspheres, the fillers (precipitated barium sulfate and talcum powder) and the titanium white powder Longbai R996 according to the formula amount into the mixture I under stirring at a low speed of 300 r / min, and dispersing at a high speed of 800 r / min for 40 min, then adding the aqueous thixotropic agent according to the formula amount, and adjusting the viscosity by using another part of the third water to obtain the aqueous heat-reflecting and heat-insulating coating, which can be packed by weight.

[0088] The third water as the diluent appearing for the first time in the table is the raw material added in step (1), the third water as the diluent appearing for the second time in the table is the raw material added in step (2), and the same applies hereinafter.

[0089] Example 2

[0090] An aqueous heat-reflecting and heat-insulating coating, raw materials are shown in Table 2

[0091] Table 2

[0092]

[0093]

[0094] The preparation method of the water-based heat-reflecting thermal insulation paint of the present example is as follows:

[0095] (1) The water-based nano-silica sol-acrylic emulsion is added into a dispersing tank according to the formula amount, and a part of the tertiary water, the water-based wetting dispersant BYK-190 and the water-based defoaming agent Tego-901w are sequentially added according to the formula amount, and are dispersed at a medium speed of 500 r / min for 20 minutes to obtain a mixture I;

[0096] (2) The water-based nano-TiO2 modified hollow glass microspheres slurry, the nano-ATO modified ceramic microspheres, the pigments and fillers (heavy calcium, kaolin) and the titanium white powder Yuxing R818 are gradually added into the mixture I under stirring at a low speed of 200 r / min, and are dispersed at a high speed of 700 r / min for 20 minutes, and after the dispersion is completed, the water-based thixotropic agent is added according to the formula amount, and the viscosity is adjusted by using another part of the tertiary water to obtain the water-based heat-reflecting thermal insulation paint, which is packaged by weight.

[0097] Example 3

[0098] A water-based heat-reflecting thermal insulation paint, and the raw materials are shown in Table 3

[0099] Table 3

[0100]

[0101]

[0102] The preparation method of the water-based heat-reflecting thermal insulation paint of the present example is as follows:

[0103] (1) The water-based nano-silica sol-acrylic emulsion is added into a dispersing tank according to the formula amount, and the tertiary water, the water-based wetting dispersant Surfynol 104E and the water-based defoaming agent DAPRO DF 1760 are sequentially added according to the formula amount, and are dispersed at a medium speed of 400 r / min for 30 minutes to obtain a mixture I;

[0104] (2) The water-based nano-TiO2 modified hollow glass microspheres slurry, the nano-ATO modified ceramic microspheres, the pigments and fillers (precipitated barium sulfate, heavy calcium), the titanium white powder Annada ATR311 are gradually added into the mixture I under stirring at a low speed of 250 r / min, and are dispersed at a high speed of 900 r / min for 30 minutes, and after the dispersion is completed, the water-based thixotropic agent is added according to the formula amount, and the viscosity is adjusted by using another part of the tertiary water to obtain the water-based heat-reflecting thermal insulation paint, which is packaged by weight.

[0105] The preparation method of the aqueous nano-silica sol-acrylic emulsion in Examples 1-3 is as follows:

[0106] (1) Preparation of modified nano-silica sol: 50 g of silica sol (30% by mass) is uniformly mixed with an anionic surfactant at a mass ratio of 10:1, and then added to a round-bottom flask containing 100 ml of distilled water. 1.5 g of an anionic alcohol ammonium salt solution and 3.5 g of a silane coupling agent are added dropwise, and ultrasonic dispersion is performed for 10 min. Then, under the condition of 55°C, stirring and dispersion are performed for 90 min to obtain the desired modified nano-silica sol.

[0107] (2) Preparation of aqueous nano-silica sol-acrylic emulsion:

[0108] S1, accurately weigh 0.7 g of emulsifier, then add 50 ml of deionized water, heat at 80°C for 10 min to dissolve the emulsifier and form an emulsion; weigh 0.3 g of initiator and add 20 mL of deionized water to form an initiation solution;

[0109] S2, weigh 10 g of modified nano-silica sol prepared in step (1), 0.6 g of silane coupling agent, and 50 g of acrylic ester monomer, so that the modified nano-silica sol is completely dissolved in the monomer. The dissolved mixture and the emulsion in step S1 are added to a three-necked flask for pre-emulsification under mechanical stirring at a speed of 500 r / min. After stirring at room temperature for 1 h, a pre-emulsion is obtained, which is then poured out after standing for use;

[0110] S3, add the initiation solution in step S1 and the pre-emulsion in step S2 to a three-necked flask, and pass in nitrogen as a protective gas with a pressure of 0.15 Mpa. Control the stirring speed at 300 r / min. When the temperature reaches 80°C, the system will slowly appear blue phase. After the blue phase is obvious, heat for 30 min to obtain the aqueous nano-silica sol-acrylic emulsion.

[0111] The specific raw material components selected are as follows: the anionic surfactant is NUOSPERSE FA 115; the acrylic ester monomer is methyl acrylate; the anionic alcohol ammonium salt solution is BYK-151; the silane coupling agent is γ-aminopropyl triethoxysilane; the emulsifier is dodecyl ammonium chloride; and the initiator is benzoyl peroxide (BPO).

[0112] The preparation method of the nano-TiO2 modified hollow glass microsphere slurry in Examples 1-3 is as follows:

[0113] (1) Put 30 parts of nano-TiO2 powder into a three-necked flask containing 100 parts of mixed solvent (deionized water and anhydrous ethanol mixed at a mass ratio of 9:1), and disperse at high speed for 20 min, then add 5 parts of silane coupling agent at 90°C, and adjust the temperature to 80°C after the dropwise addition is completed, and react for 3 h; then wash with 100 parts of anhydrous ethanol for 3 times, and dry at 120°C under vacuum after completion to obtain surface-modified TiO2 powder.

[0114] (2) Mix 50 parts of the surface-modified TiO2 powder prepared in step (1) with hollow glass microspheres (particle size D90≤115 μm, compressive strength≥500 Psi) at a ratio of 10:1, add to a round-bottom flask containing 100 ml of ethylene glycol butyl ether, and add 1.5 parts of modified polyurethane aqueous solution dropwise, ultrasonic dispersion for 40 min, then heat reflux at 120°C for 10 min, cool and filter, and place the filter in a 50°C oven for 24 h to obtain the desired nano-TiO2 modified hollow glass microspheres.

[0115] (3) Add 15 parts of the nano-TiO2 modified hollow glass microspheres prepared in step (2) and 2 parts of hydroxyethyl cellulose to 50 parts of deionized water, then add 0.5 parts of an alkyne diol molecular solution, and disperse at a dispersion speed of 500 r / min for 5 min to obtain a solution, i.e. an aqueous nano-TiO2 modified hollow glass microsphere slurry.

[0116] Among them, the selected raw material components are: silane coupling agent is KH-590; modified polyurethane aqueous solution is BorchiGen0451; alkyne diol molecular solution is Greesol A04;

[0117] The preparation method of the nano-ATO modified ceramic microspheres in Examples 1-3 is:

[0118] (1) According to the weight fraction, add 96 parts of SnO2 powder, 4 parts of Sb2O3 powder and 15 parts of modified polyurethane aqueous solution to 50 parts of deionized water, disperse at a dispersion speed of 400 r / min for 5 min, pass through a ball mill, and wet mill for 36 h to obtain a mixture water slurry;

[0119] (2) According to the weight fraction, mix 15 parts of ceramic microspheres (average particle size≤30 μm) with 100 parts of the mixture water slurry prepared in step (1), then add 0.5 parts of an alkyne diol molecular solution, disperse at a dispersion speed of 500 r / min for 60 min, then take out the ceramic microbeads, remove water by suction filtration, and then heat to 550°C and keep for 3 h to obtain nano-ATO modified ceramic microspheres with ATO (tin antimony oxide) as the surface layer and ceramic as the inner layer;

[0120] The raw material components are specifically: the modified polyurethane aqueous solution is Borchi Gen0577; the acetylenic diol molecular solution is Greesol G45.

[0121] Comparative Example 1

[0122] Different from Example 1, the mixture of nano-TiO2 powder and hollow glass microspheres is used to replace the aqueous nano-TiO2 modified hollow glass microsphere slurry in the raw materials, and other raw materials and preparation methods remain the same as Example 1.

[0123] The amount of the mixture of nano-TiO2 powder and hollow glass microspheres is 12 parts, and the mass ratio of nano-TiO2 powder to hollow glass microspheres is 10:1.

[0124] Comparative Example 2

[0125] Different from Example 1, the mixture of SnO2 powder, Sb2O3 powder and ceramic microspheres is used to replace the nano-ATO modified ceramic microspheres in the raw materials, and other raw materials and preparation methods remain the same as Example 1.

[0126] The amount of the mixture of SnO2 powder, Sb2O3 powder and ceramic microspheres is 15 parts, and the mass ratio of SnO2 powder, Sb2O3 powder and ceramic microspheres in the mixture is 96:4:15.

[0127] The products prepared in the above examples and comparative examples are subjected to the following performance tests, and the test results are obtained as shown in Table 4 below:

[0128] Table 4

[0129]

[0130]

[0131] It can be known from Table 4 that the water-based thermal reflective heat insulation coating provided by the examples of the present application has excellent corrosion resistance and weather resistance, and the acid resistance (≥72h), alkali resistance (≥72h) and other performances of the matching coating meet the index requirements, the surface paint has a service life of ≥500h under artificial aging, meets the requirements of long-term outdoor protection, and can be used for the outer wall of a crude oil storage tank.

[0132] From the data of the above comparative examples and examples, it can be known that:

[0133] The difference between Comparative Example 1 and Example 1 is that the mixture of nano-TiO2 powder and hollow glass microspheres is used to replace the aqueous nano-TiO2 modified hollow glass microspheres slurry, the infrared light reflectance, near-infrared light reflectance and hemispherical emittance of the coating are all lower than the technical index, and the mixture of nano-TiO2 powder and hollow glass microspheres cannot be uniformly dispersed, and the effect of the aqueous nano-TiO2 modified hollow glass microspheres slurry in the coating cannot be achieved.

[0134] The difference between Comparative Example 2 and Example 1 is that the mixture of SnO2 powder, Sb2O3 powder and ceramic microspheres is used to replace the nano-ATO modified ceramic microspheres, the infrared light reflectance, near-infrared light reflectance and equivalent thermal conductivity of the coating are all lower than the technical index, and the mixture of SnO2 powder, Sb2O3 powder and ceramic microspheres does not have the chemical properties of the nano-ATO modified ceramic microspheres in the coating system, does not have the mid-infrared radiation ability, and the coating cannot maintain a lower temperature under the sun.

[0135] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An aqueous heat-reflective thermal barrier coating, characterized by: By mass fraction, raw materials include: Water-based nano-silica sol-acrylic emulsion 45-55 parts Water-based nano-TiO2 modified hollow glass microspheres slurry 7-15 parts Nanometer ATO modified ceramic microspheres 12-18 parts Titanium dioxide 5-9 parts Filler 8-15 parts Water 3-11 parts Other additives 1.7-5.2 parts; The preparation method of the water-based nano-silica sol-acrylic emulsion includes the following steps: (1) Preparation of modified nano-silica sol: uniformly disperse and mix silica sol, anionic surfactant, distilled water, anionic alcohol ammonium salt solution and first silane coupling agent, then stir and disperse at 45-65℃ for 60-120min to obtain the modified nano-silica sol; (2) Mix the modified nano-silica sol, second silane coupling agent and acrylic ester monomer to make the modified nano-silica sol completely dissolved in the acrylic ester monomer to form a mixed solution; Stir the mixed solution and emulsion to perform pre-emulsification to obtain a pre-emulsion; Mix the pre-emulsion and initiator solution, stir and heat under nitrogen atmosphere and reaction system pressure of 0.15-0.2MPa, when the temperature reaches 75-90℃, the system appears blue phase, after the blue phase is obvious, keep warm for 20-40min to obtain the water-based nano-silica sol-acrylic emulsion; The preparation method of the water-based nano-TiO2 modified hollow glass microspheres slurry includes the following steps: (1) Preparation of surface modified TiO2 powder: uniformly mix nano-TiO2 powder and mixed solvent, then add third silane coupling agent at 80-100℃, after dropwise addition is completed, adjust the temperature to 70-90℃ and react for 2.5-5h; after reaction, wash and dry to obtain the surface modified TiO2 powder; (2) Preparation of nano-TiO2 modified hollow glass microspheres: uniformly mix the surface modified TiO2 powder, hollow glass microspheres, ethylene glycol butyl ether and first modified polyurethane aqueous solution, then heat and reflux at 110-130℃ for 8-15min, after cooling, filter and dry to obtain the nano-TiO2 modified hollow glass microspheres; (3) Mix the nano-TiO2 modified hollow glass microspheres, hydroxyethyl cellulose, deionized water and first alkyne diol molecular level solution uniformly to obtain the water-based nano-TiO2 modified hollow glass microspheres slurry; The preparation method of the nano-ATO modified ceramic microspheres is: (1) Mix SnO2 powder, Sb2O3 powder, second modified polyurethane aqueous solution and deionized water uniformly, then wet mill through a ball mill for 30-40h to obtain a mixture water slurry; (2) Disperse and mix ceramic microspheres, the mixture water slurry and second alkyne diol molecular level solution uniformly for 50-80min, then fish out the ceramic microbeads, remove water by suction filtration, then heat to 150℃ and keep warm for 2-4h to obtain the nano-ATO modified ceramic microspheres; The first modified polyurethane aqueous solution and the second modified polyurethane aqueous solution are one or more of Borchi Gen0451, Borchi Gen0577 and Tego760w.

2. The aqueous heat-reflective thermal barrier coating of claim 1, wherein: The other additives include water-based dispersant, water-based defoamer and water-based thixotropic agent; The water-based dispersant is one or more of BYK-190, BYK-191, Tego747w and Surfynol 104E; The water-based defoaming agent is one or more of Tego-810, Tego-901w and DAPRO DF1760; The water-based thixotropic agent is one or more of BASF PU1190, RM-8W, RM-12W and Tego-299; The filler is one or more of heavy calcium, precipitated barium sulfate, talcum powder and kaolin.

3. The aqueous heat-reflective thermal barrier coating of claim 2, wherein: The other auxiliary agent includes 0.8-2 parts of a water-based dispersant, 0.4-1.2 parts of a water-based defoaming agent, and 0.5-2 parts of the water-based thixotropic agent.

4. The aqueous heat-reflective thermal barrier coating of claim 1, wherein: In the preparation process of the modified nano-silica sol, the ratio of the silica sol, the anionic surfactant, the anionic alcohol ammonium salt solution, the first silane coupling agent and distilled water is (40-60) g:(4-6) g:(0.5-2.5) g:(2.5-4.5) g:(80-120) ml; The emulsion is an aqueous solution of an emulsifier, and the initiator solution is an aqueous solution of an initiator; The weight ratio of the modified nano-silica sol, the second silane coupling agent, the acrylic ester monomer, the emulsifier in the emulsion and the initiator in the initiator solution is (5-15) g:(0.4-0.8) g:(40-60) g:(0.5-1.0) g:(0.1-0.5) g.

5. The aqueous heat-reflective thermal barrier coating of claim 4, wherein: The anionic surfactant is one or more of NUOSPERSE FA 115, NUOSPERSE FA 182 and NUOSPERSE FA 620; The anionic alcohol ammonium salt solution is one or more of BYK-151, BYK-154 and BYK-155; The acrylic ester monomer is one or more of (methyl) acrylic acid, methyl acrylate, methyl methacrylate, styrene and acrylonitrile; The emulsifier is one or more of dodecyl ammonium chloride, cetyl pyridine bromide, octadecyl amine polyoxyethylene ether double quaternary ammonium salt and dodecyl dimethyl ammonium chloride; The initiator is one or more of benzoyl peroxide, tert-amyl 2-ethylhexyl acid peroxide, tert-butyl 2-ethylhexyl acid peroxide, tert-amyl acetate peroxide and tert-butyl benzoyl peroxide; The first and second silane coupling agents are one or more of γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, KH-590 and KH-551.

6. The aqueous heat-reflective thermal barrier coating of claim 1, wherein: In the preparation process of the surface-modified TiO2 powder, the mixed solvent is a mixture of anhydrous ethanol and deionized water in a mass ratio of (8-10):1; the mass ratio of the nano-TiO2 powder, the mixed solvent and the third silane coupling agent is (20-40) g:(90-110) g:(3-7) g. The ratio of the surface modified TiO2 powder, the hollow glass microspheres, the ethylene glycol butyl ether, the first modified polyurethane aqueous solution in the preparation process of the nano TiO2 modified hollow glass microspheres is (40-60) g: (4-6) g: (90-120) ml: (0.5-2.5) g; The ratio of the nano TiO2 modified hollow glass microspheres, the hydroxyethyl cellulose, the deionized water and the first acetylenic diol molecular solution is (10-20) g: (1-3) g: (40-60) g: (0.3-0.8) g.

7. The aqueous heat-reflective thermal barrier coating of claim 1, wherein: The mass ratio of the SnO2 powder, the Sb2O3 powder, the second modified polyurethane aqueous solution and the deionized water is (92-100) g: (2-6) g: (10-20) g: (40-60) g; The mass ratio of the ceramic microspheres, the mixture water slurry and the second acetylenic diol molecular solution is (10-20) g: (90-110) g: (0.2-0.8) g.

8. The aqueous heat-reflective thermal barrier coating of claim 6 or 7, wherein: The third silane coupling agent is one or several of γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, KH-590 and KH-551; The first acetylenic diol molecular solution and the second acetylenic diol molecular solution are one or several of Greesol A04, Greesol G45 and Greesol DF05.

9. The method of preparing an aqueous heat reflective insulating coating according to any one of claims 1-8, characterized in that, The method comprises the following steps: (1) mixing the aqueous nano silicon sol-acrylic acid emulsion, a part of water, the aqueous dispersant and the aqueous defoaming agent uniformly to obtain a mixture I; (2) mixing the aqueous nano TiO2 modified hollow glass microsphere slurry, the nano ATO modified ceramic microspheres, the titanium white powder, the filler and the mixture I uniformly, adding the aqueous thixotropic agent, and adjusting the viscosity with the remaining water to obtain the water-based thermal reflective and insulating coating.

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