Energy-saving intelligent control building water-based paint composition

Abstract

The present invention provides an energy-saving intelligent control building water-based coating composition, by modifying VO 2 The intelligent control particles are compounded with water-based fluorocarbon emulsion to obtain fluorocarbon coatings, which have extremely high thermal insulation effects, are cost-effective, and can meet industrial needs.

Description

Technical Field

[0001] The present invention relates to a water-based architectural coating composition, to a water-based fluorocarbon coating, and in particular to a water-based coating composition with energy-saving and intelligent control effects, and a preparation method thereof. Background Art

[0002] Fluorocarbon coatings are a general term for a series of coatings with fluorine-containing resins as the main film-forming materials, also known as fluorocarbon paints, fluororesin coatings, etc. In Europe, the United States and other countries, coatings with fluoroolefin polymers or copolymers of fluoroolefins and other monomers as film-forming materials are called "fluorocarbon coatings". It has comprehensive advantages that other coatings cannot match in terms of weather resistance, corrosion resistance, chemical resistance, anti-fouling and high decorative properties. As a typical representative of green and environmentally friendly coatings, nano-fluorocarbon coatings have been greatly developed in application research. Nano-environmentally friendly coatings with photocatalytic activity are constantly expanding their application areas from air purification to health care. Extraordinary weather-resistant fluorocarbon coatings are suitable for exterior wall painting of high-rise buildings in areas with severe acid rain, showing unique application value. Water-based and high-solid nano-fluorocarbon coatings do not pollute the environment during production and use, meet the direction stipulated by the building materials industry, have the primary conditions for promotion and application, and belong to a new generation of green and environmentally friendly coatings.

[0003] In the field of building glass energy saving, there are many types of energy-saving glass, which can be divided into coating type (can be divided into heat-reflecting glass and low-radiation glass, namely Low-E glass), structural type (can be divided into vacuum glass and insulating glass), heat-absorbing type, etc. Among them, the preparation process of coating glass is simple and low-cost, so it has received extensive research and attention. Due to its special phase change properties, nano VO2 is composited with organic resin to form a film, and then the film material is attached to the glass as an intelligent nano-composite film used in the field of energy-saving glass. This nano-composite film material can reduce the transmittance of near-infrared band light when the temperature is high; and when the temperature is low, it can maintain a high transmittance of near-infrared band light, so that the indoor temperature can be intelligently adjusted according to the changes in the external temperature, so that it can be kept within a suitable temperature range, reducing the use of electrical appliances such as air conditioners and electric fans, and thus achieving the effect of energy saving and emission reduction.

[0004] Specifically, vanadium dioxide (VO2), as a typical thermochromic material, can transform from monoclinic M phase to tetragonal R phase at 68°C phase transition temperature (Tc) and lead to changes in near-infrared optical properties. Due to the spontaneous temperature-controlled phase transition and the preservation of visible light transmission, it does not increase additional energy consumption such as lighting. These characteristics make VO2 materials very suitable for the application of smart energy-saving glass.

[0005] For example, in the field of transparent coating technology of CN107573725B, in particular, an ultraviolet infrared absorbing coating coated on the surface of glass that can absorb ultraviolet rays and infrared rays at the same time, specifically provides a coating liquid, glass and a manufacturing method thereof that can absorb ultraviolet rays and infrared rays. The coating liquid comprises a hydrolysis condensate of a hydrolyzable silane compound, an ultraviolet absorber and infrared absorbing nanoparticles, and further comprises an alkali metal or alkaline earth metal element, wherein the alkali metal or alkaline earth metal element can replace at least part of the hydrogen bonds in the hydrolysis condensate of the hydrolyzable silane compound, and the hydrolysis condensate of the hydrolyzable silane compound in situ encapsulates the ultraviolet absorber and the infrared absorbing nanoparticles to form an ultraviolet core-shell structure and an infrared core-shell structure respectively. The present invention can improve the high temperature resistance and durability of the coating, improve the hardness and friction resistance of the coating, and further improve the infrared absorption rate of the formed ultraviolet infrared absorbing coating.

[0006] For example, CN108504271B discloses a method for preparing an intelligent energy-saving composite film. The thermochromic slurry and the tungsten bronze endothermic slurry are mixed to form a composite slurry, and then a polymer film-forming agent is added and coated on a substrate to form an intelligent energy-saving composite film. The infrared absorption characteristics of tungsten bronze are used to improve the thermal sensitivity of the thermochromic material, increase the thermal response speed, and shorten the phase change response time. At the same time, the ultraviolet blocking characteristics of the thermochromic material are combined to improve the weather resistance of tungsten bronze, thereby obtaining a high-efficiency, high-stability, intelligent energy-saving composite film, which can be widely used in architectural glass, automotive glass, etc., and can achieve a comfortable temperature range indoors or in the car all year round, and has good application prospects.

[0007] The above processes all involve using VO2 as a phase change material, then increasing the temperature of the coating through a heat-absorbing material, and then forcing VO2 to transform from the monoclinic M phase to the tetragonal R phase and causing changes in near-infrared optical properties. However, the heat-absorbing particles rely on the absorption of infrared sunlight. The existing technology currently has the main purpose of lowering the phase change temperature of VO2, which is in urgent need of development.

[0008] There are many methods for preparing M phase, including hydrothermal method, redox method, sol-gel method, thermal decomposition method, and chemical deposition method, but all of them are complicated and multi-step, including at least synthesis and calcination steps, otherwise it is difficult to obtain high-purity M phase. Here we study the electrochemical preparation of VO2 phase, such as CN103409768B discloses a method for preparing M phase vanadium dioxide nanopowder. The method firstly mixes polyols with carbon chain lengths of 3 to 10 and monools with carbon chain lengths of 1 to 5 in a volume ratio of 1:6 to 15 to obtain a mixed alcohol solution, then adds quaternary ammonium salts with carbon chain lengths of 1 to 16 to obtain an electrolyte, wherein the concentration of the quaternary ammonium salts in the electrolyte is 1 to 5 g / L, then firstly uses a metal vanadium block as an anode and a metal platinum block or a metal vanadium block as a cathode, the distance between the two electrodes is 2 mm to 5 cm, and they are placed together in the electrolyte, and electrolyzed at a voltage of 2 to 30 V for 1 to 3 hours to obtain a reaction solution containing a precipitate, then performs solid-liquid separation and washing on the reaction solution to obtain an intermediate product, and then anneals the intermediate product at a pressure of 10 to 100 Pa and a temperature of 350 to 450° C. for 1 to 3 hours to obtain a target product with a particle size of 50 to 100 nm. The method has the characteristics of saving time, energy, being green and environmentally friendly, having a low preparation cost and being easy for large-scale industrial production. Obviously, the document obtains vanadium oxide powder by anodizing vanadium metal and then obtains the M phase by calcination, and the preparation method is complicated. Summary of the invention

[0009] Based on the understanding of the above-mentioned prior art, the present invention utilizes the special phase change properties of modified nano VO2 to intelligently adjust the light transmittance in the near-infrared band, and compounds the fluorine-tungsten modified VO2 smart control particles with tungsten bronze heat-absorbing particles that easily absorb near-infrared heat, so that the composite material can absorb heat and increase the surface temperature in a normal environment, and the phase transition temperature is effectively reduced by synthesizing the modified VO2 of fluorine-tungsten in one step through electrochemical reaction, and then the obtained fluorine-tungsten modified VO2 smart control particles are compounded with water-based fluorocarbon emulsion to obtain fluorocarbon coating.

[0010] Specifically, an energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0011] Water-based fluorocarbon emulsion: 40-70 parts;

[0012] Fluorine-tungsten modified VO2 intelligent control particles: 10-20 copies;

[0013] Tungsten bronze heat absorbing particles: 5-10 parts;

[0014] Dispersant: 2-3 parts;

[0015] Wetting agent: 0.3-0.5 parts;

[0016] Defoaming agent: 0.5-0.7 parts;

[0017] Film-forming aid: 2-4 parts;

[0018] Thickener: 0.2-0.4 parts;

[0019] 30-50 parts water;

[0020] The fluorine-tungsten modified VO2 intelligent control particles are prepared by the following method:

[0021] (1) Preparation of electrolyte: Choline chloride and propylene glycol are mixed in a molar ratio of 1:(2-4) to obtain a eutectic ionic liquid, and then sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to the eutectic ionic liquid. After being fully stirred and mixed, oxalic acid is used to adjust the pH to 2-4 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the eutectic ionic liquid is (0.2-0.3):(0.1-0.15):(0.2-0.3):(0.1-0.2);

[0022] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 5-7wt.% hydrochloric acid for 2-3 minutes, soaking in high-purity acetone for 1-3 minutes, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0023] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0024] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 140-160°C, set the heating rate of the reactor to 15-20°C / min, use constant pressure to oxidize vanadium metal, the voltage is 10-20V, the oxidation time is 2-6h, turn off the power supply, and cool naturally to room temperature;

[0025] (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and then vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified VO2 intelligent control particles.

[0026] The hydroxyl value of the aqueous fluorocarbon emulsion is (35-45) mg KOH / g;

[0027] The dispersant is selected from ammonium polyacrylate or ammonium alkylbenzene sulfonate.

[0028] The wetting agent is selected from polyoxyethylene alkylphenol ether or polyoxyethylene fatty alcohol ether.

[0029] The defoamer is selected from mineral oil defoamers or organosilicon defoamers.

[0030] The film-forming aid is selected from propylene glycol butyl ether or dipropylene glycol butyl ether.

[0031] The thickener is selected from polyurethane thickeners.

[0032] A method for preparing an energy-saving intelligent control building water-based coating composition comprises the following steps:

[0033] Add water, fluorine tungsten modified VO2 intelligent control particles, tungsten bronze endothermic particles, dispersant, part of wetting agent, part of defoaming agent into a high-speed disperser and disperse evenly, then grind to a fineness of less than 30 microns, stir at a low speed, and then

[0034] Mix the film-forming aid, water-based fluorocarbon emulsion, thickener, remaining wetting agent, remaining defoamer and water evenly according to the formula amount and disperse for 0.5-1h.

[0035] The present invention needs to select the doping ions in advance, such as CN110203972A Hubei University discloses a method for preparing M-phase vanadium dioxide nanopowder, the dopant includes any one or a combination of two of soluble salts of tungsten, molybdenum, aluminum, magnesium, niobium, osmium, fluorine and ruthenium. For example, CN103031077B of the Guangzhou Institute of Energy, Chinese Academy of Sciences discloses a method for preparing intelligent temperature control glue and film, the VO2 particles contain a dopant, the dopant is selected from at least one of tungsten, molybdenum, niobium, tantalum, gold, silver, chromium, zirconium, fluorine and phosphorus, and the content of the dopant is 0-5% of the molar content of VO2. However, the above selections are disordered and the purpose is extremely unclear. The present invention is the first to synthesize M-phase VO2 in one step under electrochemical-solvothermal composite conditions. The impurity ions are selected from fluorine and tungsten. The principle may be that tungsten ions and fluorine ions replace vanadium atoms or oxygen atoms in the lattice. After replacing the vanadium atoms in the original lattice, tungsten will produce certain stresses, causing the lattice to be distorted to form lattice defects, thereby destroying the stability of the VO2 phase transition. After doping, when VO2 undergoes a phase transition, the outer electrons of the vanadium atoms will have energy band overlap at low temperatures, so the phase transition temperature will be reduced. The tungsten ion W6+ has a larger ion radius than V4+ and a larger charge number than V4+. It replaces the lattice position of the V atom and easily forms a lattice defect. At the same time, F- is more likely to enter the defect position or occupy the oxygen position, thereby more effectively reducing the phase transition temperature of VO2.

[0036] The present invention adopts ionic liquid as electrolyte. Glycerol in the ionic liquid has high reducing property under solvent thermal conditions, and can effectively reduce vanadium pentoxide oxidized and dropped on the anode surface. The acidity of the ionic liquid is adjustable, and there are few side reactions. The ionic liquid can effectively and simply oxidize V metal without other obvious side reactions. Its property as a solvent is significantly higher than that of a water system. In addition, glycerol and ascorbic acid have high reducing property under high pressure and high temperature conditions, which is convenient for reducing oxidized vanadium oxide, that is, V2O5 obtained by anodic oxidation of vanadium metal drops from the anode. After V2O5 drops from the anode surface, the anodic oxidation process no longer occurs, and V2O5 enters the electrolyte, and the reduction process of V2O5 occurs in the electrolyte. Glycerol and ascorbic acid have suitable reducing property under high pressure and high temperature conditions, and the situation that the electrolyte reduction is greater than the anode oxidation and the oxide is difficult to be peeled off from the anode surface will not occur. In addition, hydrogen peroxide is mainly used to improve the oxidizability, and oxalic acid is used as a pH regulator because oxalic acid itself can react with V2O5 to generate water and CO2. The release of CO2 can increase the pressure of the solvent thermal reactor. Therefore, the hydrothermal temperature of the present invention only needs a conventional temperature of 140-160°C, without other high temperatures in the prior art. The final preparation of VO2 is as shown in the attached Figure 2 As shown, the product is spherical with a rough surface and a size of about 2-10 μm.

[0037] In order to improve the compatibility of vanadium oxide in the coating of the present invention, it is necessary to increase or decrease the dispersant, wetting agent and defoaming agent in the solution. The active groups contained in the wetting agent are directionally adsorbed on the surface of VO2, which can increase the affinity between the paint base and VO2; at the same time, it can reduce the paint

[0038] The surface tension of the material accelerates the compatibility of the paint base and VO2, replaces the water and air adsorbed on the surface of the pigment particles, thereby helping the grinding and dispersing equipment to disperse the VO2, reducing the grinding time, improving the efficiency and reducing the grinding energy consumption.

[0039] In addition to having the same wetting effect as a wetting agent, the dispersant's active group can be adsorbed on the surface of VO2 crushed into tiny particles at one end, and the other end can be solvated into the paint base to form an adsorption layer (the more adsorption groups, the longer the chain links, the thicker the adsorption layer), generating charge repulsion (water-based paint) or entropy repulsion (solvent-based paint), so that the VO2 particles are dispersed and suspended in the paint base for a long time, avoiding re-flocculation.

[0040] For defoamers used in water-based fluorocarbon coatings, the actual resin system, formula design, types and amounts of other additives, construction methods and conditions should be considered comprehensively. The general principle is to use defoamer products with strong defoaming ability, good compatibility, no effect on dispersibility, and long-lasting defoaming ability.

[0041] Film-forming aids can dissolve or swell the polymer particles in the emulsion, so that the particles can also produce plastic flow and elastic deformation and aggregate into a film at a lower temperature as the water evaporates. However, the film-forming aids can evaporate again in a short time after the film is formed, so as not to affect the glass transition temperature of the coating, and the coating will not become sticky again at high temperatures. The minimum film-forming temperature of the emulsion has an important influence on the hardness, glass transition temperature and low-temperature coating performance of the coating. When the minimum film-forming temperature is high, the hardness and gloss of the coating are high, but it cannot be painted at a slightly lower temperature; when the minimum film-forming temperature is too low, the low-temperature coating performance is good, but the coating has a low glass transition temperature, becomes soft and sticky at high temperatures, and has poor stain resistance. The basic function of the film-forming aid is to lower the minimum film-forming temperature of the emulsion and latex paint, so that the latex paint can be painted at low temperatures.

[0042] Thickeners have a regulating effect and improvement function on the thickening, stabilization and rheological properties of water-based fluorocarbon coatings. In the production stage of water-based fluorocarbon coatings, thickeners can improve the stability of the emulsion and help disperse and grind the particle fillers. In the storage stage, the thickeners coat the VO2 particles in the coating in a monolayer of the thickener, and slow down the sedimentation of the VO2 particles due to the increase in viscosity, thereby improving the stability of the coating and improving its freeze-thaw resistance and mechanical properties. In the construction stage, the viscosity of the water-based fluorocarbon coating is reduced effortlessly at high shear rates during roller and brush coating due to the increase in the viscosity of the coating and making it thixotropic. After application, the shear force is eliminated and the viscosity of the coating is restored, thereby preventing sagging during coating. At the same time, the thickener can also delay the drying time of the coating film and improve the coating performance of the water-based fluorocarbon coating.

[0043] Beneficial technical effects: (1) The present invention utilizes the special phase change properties of modified nano VO2 to intelligently adjust the light transmittance in the near-infrared band, and compounds the fluorine-tungsten modified VO2 smart control particles with tungsten bronze heat-absorbing particles that easily absorb near-infrared heat, so that the composite material can absorb heat in a normal environment to increase the surface temperature, and the modified VO2 of fluorine-tungsten is synthesized in one step by electrochemistry to effectively reduce the phase transition temperature; (2) The ionic liquid used in the present invention is an electrolyte, and the reducing property is compounded with alcohol, ascorbic acid, and oxalic acid, which can effectively reduce VOx to obtain pure phase VO2, and can maintain a low solvent thermal environment; (3) The obtained fluorine-tungsten modified VO2 smart control particles are compounded with water-based fluorocarbon emulsion to obtain a fluorocarbon coating with extremely high thermal insulation effect, high cost performance, and can meet industrial needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Attached Figure 1 XRD patterns of VOx prepared in Example 1 of the present invention.

[0045] Attached Figure 2 Morphology of VO2 prepared in Example 2 of the present invention.

[0046] Attached Figure 3 DSC diagram of Example 2 of the present invention. DETAILED DESCRIPTION Example 1

[0047] An energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0048] Water-based fluorocarbon emulsion: 40 parts;

[0049] Fluorine-tungsten modified VO2 intelligent control particles: 10 parts;

[0050] Tungsten bronze heat absorbing particles: 5 parts;

[0051] Dispersant: 2 parts;

[0052] Wetting agent: 0.3 parts;

[0053] Defoaming agent: 0.5 parts;

[0054] Film-forming aid: 2 parts;

[0055] Thickener: 0.2 parts;

[0056] 30 parts water;

[0057] The fluorine-tungsten modified VO2 intelligent control particles are prepared by the following method:

[0058] (1) Preparation of electrolyte: Choline chloride and propylene glycol are mixed in a molar ratio of 1:(2) to obtain a eutectic ionic liquid, and then sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to the eutectic ionic liquid. After being fully stirred and mixed, oxalic acid is used to adjust the pH to 2 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the eutectic ionic liquid is (0.2):(0.1):(0.2):(0.1);

[0059] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 5wt.% hydrochloric acid for 2 minutes, soaking in high-purity acetone for 1 minute, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0060] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0061] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 140°C, set the heating rate of the reactor to 15°C / min, use constant pressure to oxidize vanadium metal, the voltage is 10V, the oxidation time is 2h, turn off the power supply, and cool naturally to room temperature;

[0062] (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and then vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified VO2 intelligent control particles.

[0063] The dispersant is selected from ammonium polyacrylate.

[0064] The wetting agent is selected from polyoxyethylene alkylphenol ethers.

[0065] The defoamer is selected from mineral oil defoamers.

[0066] The film-forming aid is selected from propylene glycol butyl ether.

[0067] The thickener is selected from polyurethane thickeners. Example 2

[0068] An energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0069] Water-based fluorocarbon emulsion: 55 parts;

[0070] Fluorine-tungsten modified VO2 intelligent control particles: 15 parts;

[0071] Tungsten bronze heat absorbing particles: 7.5 parts;

[0072] Dispersant: 2.5 parts;

[0073] Wetting agent: 0.4 parts;

[0074] Defoaming agent: 0.6 parts;

[0075] Film-forming aid: 3 parts;

[0076] Thickener: 0.3 parts;

[0077] 40 parts water;

[0078] The fluorine-tungsten modified VO2 intelligent control particles are prepared by the following method:

[0079] (1) Preparation of electrolyte: Choline chloride and propylene glycol are mixed in a molar ratio of 1:(3) to obtain a eutectic ionic liquid, and then sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to the eutectic ionic liquid. After being fully stirred and mixed, oxalic acid is used to adjust the pH to 3 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the eutectic ionic liquid is (0.25):(0.125):(0.25):(0.15);

[0080] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 6wt.% hydrochloric acid for 2.5min, soaking in high-purity acetone for 2min, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0081] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0082] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 150°C, set the heating rate of the reactor to 17.5°C / min, use constant voltage to oxidize vanadium metal, the voltage is 15V, the oxidation time is 4h, turn off the power supply, and cool naturally to room temperature;

[0083] (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and then vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified VO2 intelligent control particles.

[0084] The dispersant is selected from ammonium polyacrylate.

[0085] The wetting agent is selected from polyoxyethylene fatty alcohol ethers.

[0086] The defoamer is selected from silicone defoamers.

[0087] The film-forming aid is selected from propylene glycol butyl ether.

[0088] The thickener is selected from polyurethane thickeners. Example 3

[0089] An energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0090] Water-based fluorocarbon emulsion: 70 parts;

[0091] Fluorine-tungsten modified VO2 intelligent control particles: 20 copies;

[0092] Tungsten bronze heat absorbing particles: 10 parts;

[0093] Dispersant: 3 parts;

[0094] Wetting agent: 0.5 parts;

[0095] Defoaming agent: 0.7 parts;

[0096] Film-forming aid: 4 parts;

[0097] Thickener: 0.4 parts;

[0098] 50 parts water;

[0099] The fluorine-tungsten modified VO2 intelligent control particles are prepared by the following method:

[0100] (1) Preparation of electrolyte: Choline chloride and propylene glycol in a molar ratio of 1:(4) are mixed evenly to obtain a eutectic ionic liquid, and then sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to the eutectic ionic liquid. After being fully stirred and mixed evenly, oxalic acid is used to adjust the pH to 4 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the eutectic ionic liquid is (0.3):(0.15):(0.3):(0.2);

[0101] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 7wt.% hydrochloric acid for 2-3 minutes, soaking in high-purity acetone for 1-3 minutes, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0102] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0103] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 160°C, set the heating rate of the reactor to 20°C / min, use constant pressure to oxidize vanadium metal, the voltage is 20V, the oxidation time is 6h, turn off the power supply, and cool naturally to room temperature;

[0104] (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and then vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified VO2 intelligent control particles.

[0105] The dispersant is selected from ammonium alkylbenzene sulfonate salts.

[0106] The wetting agent is selected from polyoxyethylene fatty alcohol ethers.

[0107] The defoamer is selected from silicone defoamers.

[0108] The film-forming aid is selected from dipropylene glycol butyl ether.

[0109] The thickener is selected from polyurethane thickeners.

[0110] Comparative Example 1, an energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0111] Water-based fluorocarbon emulsion: 55 parts;

[0112] Smart Control Granules: 15 servings;

[0113] Tungsten bronze heat absorbing particles: 7.5 parts;

[0114] Dispersant: 2.5 parts;

[0115] Wetting agent: 0.4 parts;

[0116] Defoaming agent: 0.6 parts;

[0117] Film-forming aid: 3 parts;

[0118] Thickener: 0.3 parts;

[0119] 40 parts water;

[0120] Wherein, the intelligent control particles are prepared by the following method:

[0121] (1) preparing an electrolyte: mixing choline chloride and propylene glycol in a molar ratio of 1:(3) to obtain a eutectic ionic liquid, then adding hydrogen peroxide to the eutectic ionic liquid, stirring and mixing thoroughly, and adjusting the pH to 3 with hydrochloric acid to obtain an electrolyte;

[0122] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 6wt.% hydrochloric acid for 2.5min, soaking in high-purity acetone for 2min, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0123] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0124] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 150°C, set the heating rate of the reactor to 17.5°C / min, use constant voltage to oxidize vanadium metal, the voltage is 15V, the oxidation time is 4h, turn off the power supply, and cool naturally to room temperature;

[0125] (5) Post-processing: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and vacuum dry it at room temperature to obtain powdered intelligent control particles.

[0126] The dispersant is selected from ammonium polyacrylate.

[0127] The wetting agent is selected from polyoxyethylene fatty alcohol ethers.

[0128] The defoamer is selected from silicone defoamers.

[0129] The film-forming aid is selected from propylene glycol butyl ether.

[0130] The thickener is selected from polyurethane thickeners.

[0131] Comparative Example 2, an energy-saving intelligent control building water-based coating composition, the coating comprises the following components by weight:

[0132] Water-based fluorocarbon emulsion: 55 parts;

[0133] Fluorine tungsten modified intelligent control particles: 15 parts;

[0134] Tungsten bronze heat absorbing particles: 7.5 parts;

[0135] Dispersant: 2.5 parts;

[0136] Wetting agent: 0.4 parts;

[0137] Defoaming agent: 0.6 parts;

[0138] Film-forming aid: 3 parts;

[0139] Thickener: 0.3 parts;

[0140] 40 parts water;

[0141] The fluorine-tungsten modified intelligent control particles are prepared by the following method:

[0142] (1) Preparation of electrolyte: sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to a deionized water solution, and after being fully stirred and mixed, oxalic acid is used to adjust the pH to 3 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the low eutectic ionic liquid is (0.25): (0.125): (0.25): (0.15);

[0143] (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 6wt.% hydrochloric acid for 2.5min, soaking in high-purity acetone for 2min, repeatedly rinsing with deionized water and drying with cold air, and using a copper sheet as cathode;

[0144] (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor;

[0145] (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 150°C, set the heating rate of the reactor to 17.5°C / min, use constant voltage to oxidize vanadium metal, the voltage is 15V, the oxidation time is 4h, turn off the power supply, and cool naturally to room temperature;

[0146] (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified intelligent control particles.

[0147] The dispersant is selected from ammonium polyacrylate.

[0148] The wetting agent is selected from polyoxyethylene fatty alcohol ethers.

[0149] The defoamer is selected from silicone defoamers.

[0150] The film-forming aid is selected from propylene glycol butyl ether.

[0151] The thickener is selected from polyurethane thickeners.

[0152] XRD tests were performed on Example 2 and Comparative Examples 1-2, and it was found that only Example 2 could obtain pure VO2 phase. In comparison, in Comparative Example 1, the lack of doping ions and reducing agents resulted in the inability to effectively reduce the vanadium tungsten oxide obtained by anodization. In Comparative Example 2, the lack of ionic liquid resulted in the corresponding VO2 phase diffraction peak in the obtained product, but with more impurities. The main reason was that the hydrothermal conditions were insufficient and the temperature was too low, which made it difficult to obtain pure VO2 at low temperature and low pressure. In addition, it should be noted that a small amount of doped tungsten and fluorine did not change the crystal form of VO2, see Appendix. Figure 1 .

[0153] The DSC test was performed on the fluorine tungsten VO2 modified according to Example 2, and its phase transition temperature was 41.0°C. If tungsten VO2 modified particles were prepared according to Example 2, the phase transition temperature was 47.3°C. If fluorine VO2 modified particles were prepared according to Example 2, the phase transition temperature was 53.1°C. If VO2 modified particles were prepared according to Example 2, the phase transition temperature was 60.5°C, which was also lower than the phase transition temperature of about 68°C in the prior art. That is, the phase transition temperature of VO2 depends on the doping composition and particle morphology.

[0154] As attached Figure 3 As shown, the fluorine tungsten VO2 particles and coatings prepared in Example 2 (glass plate as substrate) were subjected to DSC testing. The phase transition temperature did not change significantly, but the phase transition content decreased significantly. The phase transition temperature of VO2 obtained in Example 2 was 41.0°C, and the enthalpy area was 27.32 J / g. The phase transition temperature of the coating obtained in Example 2 was 41.3°C, and the enthalpy area was 5.9 J / g. The glass plate and the coated glass plate obtained in Example 2 were tested. The ultraviolet transmittance, visible light transmittance, and infrared transmittance of the glass plate were 74%, 95%, and 86%, respectively. The transmittance of Example 2 was 21%, 68%, and 34%. A 300W infrared lamp was used to perform a heat insulation test on the glass plate and the glass plate coating. After 30 minutes (room temperature), the temperatures of the glass plate and the glass plate coating were 73.5°C and 65.2°C, respectively, and the temperatures in the test box passing through the glass plate and the glass plate coating were 56.1°C and 42.2°C, respectively, proving that the coating obtained in Example 2 has a good heat insulation effect. In addition, when the room temperature was adjusted to 10°C, the temperatures of the glass plate and the glass plate coating were 29.8°C and 28.3°C, respectively, and the temperatures in the test box passing through the glass plate and the glass plate coating were 33.0°C and 36.2°C, respectively, i.e., it has a heat preservation function.

[0155] For those skilled in the art, various other corresponding changes and modifications can be made according to the above technical solutions and concepts, and all of these changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. An energy-saving intelligent control building water-based coating composition, characterized in that The coating comprises the following components by weight: Water-based fluorocarbon emulsion: 40-70 parts; Fluorine-tungsten modified VO2 intelligent control particles: 10-20 copies; Tungsten bronze heat absorbing particles: 5-10 parts; Dispersant: 2-3 parts; Wetting agent: 0.3-0.5 parts; Defoaming agent: 0.5-0.7 parts; Film-forming aid: 2-4 parts; Thickener: 0.2-0.4 parts; 30-50 parts water; Among them, the fluorine-tungsten modified VO2 intelligent control particles are synthesized in one step under electrochemical-solvothermal composite conditions. The preparation process is as follows: (1) Preparation of electrolyte: Choline chloride and propylene glycol are mixed in a molar ratio of 1:(2-4) to obtain a eutectic ionic liquid, and then sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide are added to the eutectic ionic liquid. After being fully stirred and mixed, oxalic acid is used to adjust the pH to 2-4 to obtain an electrolyte, wherein the molar ratio of sodium tungstate, sodium fluoride, ascorbic acid and hydrogen peroxide in the eutectic ionic liquid is (0.2-0.3):(0.1-0.15):(0.2-0.3):(0.1-0.2); (2) Surface treatment of substrate: Using metal vanadium as anode and undergoing surface pretreatment, the pretreatment process includes: soaking in 5-7wt.% hydrochloric acid for 2-3 minutes, soaking in high-purity acetone for 1-3 minutes, repeatedly rinsing with deionized water and drying with cold air; using copper sheet as cathode; (3) Reactor setup: introduce the electrolyte prepared in step (1) into the reactor, connect the cathode and anode to a power source and immerse them in the electrolyte, and seal the reactor; (4) Electro-oxidation of vanadium metal: Turn on the power supply, set the temperature of the reactor to 140-160°C, set the heating rate of the reactor to 15-20°C / min, use constant pressure to oxidize vanadium metal, the voltage is 10-20V, the oxidation time is 2-6h, turn off the power supply, and cool naturally to room temperature; (5) Post-treatment: Filter the electrolyte, rinse the filtered product with anhydrous ethanol and deionized water, and then vacuum dry it at room temperature to obtain powdered fluorine-tungsten modified VO2 intelligent control particles.

2. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The hydroxyl value of the aqueous fluorocarbon emulsion is (35-45) mg KOH / g.

3. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The dispersant is selected from ammonium polyacrylate or ammonium alkylbenzene sulfonate.

4. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The wetting agent is selected from polyoxyethylene alkylphenol ether or polyoxyethylene fatty alcohol ether.

5. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The defoamer is selected from mineral oil defoamers or organosilicon defoamers.

6. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The film-forming aid is selected from propylene glycol butyl ether or dipropylene glycol butyl ether.

7. The energy-saving intelligent control building water-based coating composition according to claim 1, characterized in that The thickener is selected from polyurethane thickeners.

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